A protection system for an electrical power line system of the type comprising radially connected power line sections, wherein a first electrically upstream one of the line sections is connectable to a power source. The protection system comprises at least one relay installed at or near at least the upstream end of each line section to protect that line section, each relay having an associated circuit breaker. The relays are provided with a first set of accelerated overcurrent functions and a second set of under-current/under-voltage functions, the relays being directional and the first and second sets of functions being time graded in reverse to each other. The first and second sets of functions are distributed amongst the relays such that if an under-current/under-voltage function in a second relay located downstream of a first relay triggers operation of a circuit breaker associated with the second relay, an accelerated overcurrent function in the first relay triggers accelerated operation of a circuit breaker associated with the first relay, thereby to isolate from the power source the line section that the first relay protects.

One of the most important known fault protection techniques for power lines (including power cables) is the so-called Overcurrent (OC) protection technique. See, e.g., GEC Alsthom Protection and Control Ltd, "Protective Relays Application Guide", Third Edition, June 1987. Protection devices using the technique monitor the current in the power line through connections to current transformers in the line and when the current exceeds a predefined threshold, the protection device issues a trip signal to open a power line circuit breaker associated with the device. Such protection devices are conveniently referred to as 'relays' and they have current and time settings which are adjustable to grade the settings with respect to the settings of their neighboring relays to allow correct discrimination to be achieved during fault or overload conditions. In power networks having several sections of power line connected in series without significant impedance at their junctions, and where the source impedance is much greater than the impedance of the sections, there will be little difference between the magnitudes of currents which flow for faults in different positions on the network. In these circumstances, grading of the relays' current settings ("current grading") is not able to offer satisfactory performance, so correct discrimination is obtained during fault conditions by using time graded relays, i.e., relays set to operate after different time delays. The timing difference between the relays associated with adjacent sections can be made sufficient to allow the appropriate circuit-breaker to open and clear the fault on its section before the relay associated with adjacent section nearer to the source can initiate the opening of its circuit breaker.
FIG. 1 shows a radially connected power line system provided with a known type of protection scheme based on time graded OC relays. Looked at from the source end of the system, a source S feeds power onto a busbar 1 and a line section L1 feeds current from busbar 1 to busbar 2. Current flowing in line section L1 near busbar 1 is measured by a current transformer CT, whose signal is passed to a relay R1 for controlling an associated circuit breaker B1, shown by the symbol X. The current fed into busbar 2 by section L1 is distributed to two further sections L21 and L22, which are connected to busbar 2 in parallel (though of course each of L21 and L22 considered individually is in series with L1). Sections L21 and L22 in turn carry the current to two further busbars 31 and 32, each of which have further line sections L31, L32, L33, etc., connected to them in parallel, and so on to complete the system. Hence, in such a power line system, current is said to radiate from the source end of the system to its far end through the above-described branching paths comprising "radially connected" power line sections. Similarly to section L1, each further line section L21, L22, etc., is provided with its own current transformer feeding line section current measurements to protection relays R21, R22, etc., with their associated circuit breakers B21, B22, etc. Each relay R1, R21, R22, etc., with its associated circuit breaker and line current transformer (which may be combined with a voltage transformer) is installed proximate, i.e., at or near, the electrically upstream end of each line section, this being the end nearest the source.
In such a power line system, with a single generating source at one end as shown, fault currents can flow in only one direction, i.e., from source to fault. To protect their line sections, each relay installed at a different position on the system is arranged to operate with a different time delay. The sequence from right to left is tf4→tf3→tf2→tf1, with operating times of 0.1→0.5→0.9→1.3 seconds, respectively. As can be seen from FIG. 1, the relays located in line sections nearer the source S have slower operating times than the relays in sections further away. A fault such as F1 in section L1 will cause higher current levels than a fault such as F3 in a section remote from the source S. In fact, fault currents in section L1 are likely to be so high that they can only be allowed to persist for a short period, which conflicts with the requirement for slower operating times. It will therefore be realized that although it is very easy to select the slower operating times needed to ensure that correct discrimination will be achieved when relays with predetermined time delays are used, their use must be restricted to networks with relatively few serially connected sections.


A magnetic head of the present application has a sensor which employs the extraordinary magnetoresistance (EMR) effect. The magnetic head includes a body of semiconductor material positioned over a tail end of a carrying mechanism; a field receiving surface of the body oriented perpendicular to a sensing plane of the magnetic head; an electrically conducting shunt coupled to a first end of the body; a plurality of electrically conducting contacts coupled to a second end of the body opposite the first end; and a magnetic flux guide having a first end at least partially formed over the field receiving surface and a second end exposed at the sensing plane. Advantageously, the magnetic flux guide orients a signal field of recorded data from a magnetic medium in a suitable direction for the field receiving surface, at least partially shields the field receiving surface magnetically, and allows for positioning of the magnetic head on the tail end of the carrying mechanism. Preferably, the slider over which the body is formed is made from a material of similar crystal structure, but higher electrical resistance, as the material of the body. In this way, the body may be grown epitaxially from the slider and be integrally formed therewith.

1. Field of the Technology
This invention relates generally to magnetic heads of magnetic storage devices such as disk drives, and more particularly to magnetic heads having extraordinary magnetoresistance (EMR) sensors.
2. Description of the Related Art
Magnetoresistive (MR) sensors have typically been used as read sensors in hard disk drives. An MR sensor detects magnetic field signals through the resistance changes of a read element, fabricated of a magnetic material, as a function of the strength and direction of magnetic flux being sensed by the read element. The conventional MR sensor, such as that used as a MR read head for reading data in magnetic recording disk drives, operates on the basis of the anisotropic magnetoresistive (AMR) effect of the bulk magnetic material, which is typically permalloy. A component of the read element resistance varies as the square of the cosine of the angle between the magnetization direction in the read element and the direction of sense current through the read element. Recorded data can be read from a magnetic medium, such as the disk in a disk drive, because the external field from the recorded magnetic medium (the signal field) causes a change in the direction of magnetization in the read element, which causes a change in resistance of the read element and a resulting change in the sensed current or voltage. Other types of sensors, such as GMR sensors and tunnel valve sensors, also utilize magnetic materials for operation.
Today's sensors are becoming very small, with trackwidths (TWs) approaching between about 50-200 nanometers (nm). With increasing areal densities and advancements in electron beam (e-beam) lithography, the trackwidth may shrink even below 50 nm. Given such reduced sizes, conventional sensors increasingly suffer from magnetic noise. In particular, the volume of a free layer of the sensor needs to be reduced in accordance with the trackwidth. However, a reduced volume makes the free layer magnetization more susceptible to thermal agitation, which leads to magnetic noise. Therefore, a sensor made from non-magnetic materials may be desirable for detecting small magnetic excitations such as those found in an ultrahigh-density disk drive.
A recently recognized type of semiconductor material exhibits extraordinary magnetoresistance (EMR). While such semiconductor material has been recognized as a candidate for use in storage technology, there have been minimal advancements in actual implementations of such application. The different characteristics exhibited by the EMR material with respect to traditional materials used with MR magnetic heads represent one reason for this lack of advancement. In particular, the MR magnetic heads can not simply be substituted with EMR magnetic heads. EMR magnetic heads require the signal field to be perpendicular to a field receiving surface of the magnetic head to achieve the EMR effect.
Accordingly, there is a need to solve this implementation issue so that EMR magnetic heads may be suitable for use in magnetic recording disk drives or any other desired storage technology context.

EMR magnetic head having a magnetic flux guide and a body formed at a tail end of a slider

Hitachi Global Storage Technologies Netherlands B.V.


Method and arrangement for implementing a system (10) for providing multi-angular SPECT radiation sampling utilizing slant-angle collimation. The system (10) includes a collimator (13) positioned between a radiating mass (19) within a patient (60) and a radiation detector (21). The collimator (13) is spaced apart from a translational path (25) of the radiating mass (19) at a predefined distance (24). A plurality of apertures (27) extend through the collimator (13) and each forms a passageway (28) for radiation rays (20) emanating from the radiating mass (19) in a direction substantially aligned with a longitudinal axis (29) of the respective passageway (29) and in this manner enables the aligned radiation rays (20) to strike the radiation detector (21). The plurality of passageways (28) include a first group (30) of passageways adjacently aligned in a first row (32) and arranged so that the longitudinal axes (29) of the first group (30) of passageways (32) are substantially contained in a first plane (34) oriented substantially perpendicularly to a central plane (16) of the collimator (13). Each of the parallel longitudinal axes (29) of the first row (32) of passageways are obliquely oriented with respect to the central plane (16) of the collimator (13) with an included angle (36) therebetween. Each of the included angles, when measured clockwise from the central plane (16) or face of the collimator (13) to a respective longitudinal axis, is an acute angle.

1. Field of the Invention
The present invention relates to systems and methods used in radiation imaging; and more particularly, to collimators utilized in cooperation with radiation detectors that permit only desired radiation to strike the detector thereby producing a more accurate image-of-interest, typically of an internal portion of a patient when medical and diagnostic applications are considered.
2. Description of the Background Art
In conventional radiation imaging arrangements, collimators are used in a wide variety of equipment in which it is desired to permit only beams of radiation emanating along a particular path to pass a selected point or plane. Collimators are frequently used in radiation imagers to ensure that only radiation beams passing along a direct path from the known radiation source strike the detector thereby minimizing detection of beams of scattered or secondary radiation.
Particularly in radiation imagers used for medical diagnostic analysis or for non-destructive evaluation procedures, it is important that only radiation emanating from a known source and passing along a direct path from that source be detected and processed by the imaging equipment. If the detector is struck by undesired radiation such as that passing along non-direct paths to the detector, performance of the imaging system can be degraded.
Collimators are positioned to substantially absorb the undesired radiation before it reaches the detector. The collimator includes (or is manufactured from) a relatively high atomic number material and the collimator is positioned so that undesired radiation strikes the body of the collimator and is absorbed before being able to strike the detector. In a typical detector system the collimator includes barriers associated with the detector and located in the direction of the radiation source. An example exists in radiation imaging systems used for medical diagnosis which use a small point source of radiation to expose the patient under examination. The radiation passes through the patient and strikes a radiation detector that is oppositely positioned.
Another diagnostic technology that incorporates collimators is the gamma camera typically utilized in Single Photon Emission Computed Tomography (SPECT) scanning, which is a nuclear medicine procedure in which gamma camera(s) have traditionally rotated around the patient taking pictures from many angles. From these images, a computer is employed to form a tomographic (cross-sectional) image of the internal area-of-interest within the patient using a calculation process that is similar to that used in X-ray Computed Tomography (CT) and in Positron Emission computed Tomography (PET).
In the instance of SPECT scanning, a subject (patient) is infused with a radioactive substance that emits gamma rays. Conventionally, a gamma camera includes a transducer to receive the gamma rays and record an image therefrom. In order for the image to be a true representation of the subject being investigated, a collimator having collimating apertures is positioned between the transducer and the subject to screen out all of the gamma rays except those directed along a straight line through the collimating apertures between a particular part of the subject and a corresponding particular part of the transducer. Traditionally, the collimator is made of a radiation opaque material such as lead, and collimating apertures have been formed therein by various means such as drilling, casting, or lamination of corrugated strips of lead foil.
In conventional SPECT system designs, the gamma cameras have been supported on gantries that rotate the camera heads through a specific angular range around the patient, usually covering one hundred eighty or three hundred and sixty degrees. One drawback associated with this requirement however, is that such gantry systems are relatively expensive subsystems of the diagnostic tool because they must be capable of providing rapid rotation is of the large and heavy camera heads through very precise orbits about the patient. As a result, the object of the present invention is to accommodate the use of lower cost, simplified gantries, without sacrificing image quality, or driving the cost of related subsystems higher.

System and method for providing slant-angle collimation for nuclear medical imaging


This invention relates to a polymeric membrane composition utilizing the non-hazardous compound 4-aminophenyl disulfide (“APD”), a method of making the polymeric membrane, and a process for separating components of a feedstream utilizing the polymeric membrane. More particularly, but not by way of limitation, this invention relates to utilizing the polymeric membrane composition in a process for the separation of aromatics from a hydrocarbon feedstream containing aromatics and aliphatic compounds.

Polymeric membrane based separation processes such as reverse osmosis, pervaporation and perstraction are conventional. In the pervaporation process, a desired feed component, e.g., an aromatic component, of a mixed liquid feed is preferentially absorbed by the membrane. The membrane is exposed at one side to a stream comprised of a mixture of liquid feeds and a vacuum is applied to the membrane at the opposite side so that the adsorbed component migrates through the membrane and is removed as a vapor from the opposite side of the membrane via a solution-diffusion mechanism. A concentration gradient driving force is therefore established to selectively pass the desired components through the membrane from its upstream side to its downstream side.
The perstraction process is utilized to separate a liquid stream into separate products. In this process, the driving mechanism for the separation of the stream into separate products is provided by a concentration gradient exerted across the membrane. Certain components of the fluid will preferentially migrate across the membrane because of the physical and compositional properties of both the membrane and the process fluid, and will be collected on the other side of the membrane as a permeate. Other components of the process fluid will not preferentially migrate across the membrane and will be swept away from the membrane area as a retentate stream. Due to the pressure mechanism of the perstraction separation, it is not necessary that the permeate be extracted in the vapor phase. Therefore, no vacuum is required on the downstream (permeate) side of the membrane and permeate emerges from the downstream side of the membrane in the liquid phase. Typically, permeate is carried away from the membrane via a swept liquid.
The economic basis for performing such separations is that the two products achieved through this separation process (i.e., retentate and permeate) have a refined value greater than the value of the unseparated feedstream. Membrane technology based separations can provide a cost effective processing alternative for performing the product separation of such feedstreams. Conventional separation processes such as distillation and solvent extraction can be costly to install and operate in comparison with membrane process alternatives. These conventional based processes can require a significant amount of engineering, hardware and construction costs to install and also may require high levels of operational and maintenance personnel costs to maintain the associated facilities in an operating status. Additionally, most of these processes require the heating of the process streams to relatively high temperatures in order to separate different components during the processing steps resulting in higher energy costs than are generally required by low-energy membrane separation processes.
In general, the membrane technology in the present art has the benefit of lower per unit energy costs per volume of separation than the conventional technologies in present art. However, a major obstacle in perfecting the commercial operation of membrane separation technologies is to improve the flux and selectivity characteristics of the current membrane systems in order to make the construction costs and separation efficiencies of membrane technologies economically viable, for example, on a refinery scale operations and on-board vehicle separation processes.
A myriad of polymeric membrane compositions have been developed over the years. Such compositions include polyurea/urethane membranes (U.S. Pat. No. 4,914,064); polyurethane imide membranes (U.S. Pat. No. 4,929,358); polyester imide copolymer membranes (U.S. Pat. No. 4,946,594); polyimide aliphatic polyester copolymer membranes (U.S. Pat. No. 4,990,275); and diepoxyoctane crosslinked/esterfied polyimide/polyadipate copolymer (diepoxyoctane PEI) membranes (U.S. Pat. No. 5,550,199).
These copolymeric membranes are generally comprised of "soft segments" and "hard segments" which form polymer chains in the membrane. The soft segments of the polymer provide the active area for the selective diffusion of the permeate through the membrane. However, these soft segments of the membrane have limited structural and thermal strength characteristics. Therefore, in order to provide structural strength to the membrane, a hard segment polymer (e.g., the reaction product of a dianhydride and a diamine) is added to the soft segment polymer in a suitable solvent to form long copolymer chains in the final membrane preferably comprised of alternating soft and hard polymer segments. These hard segments provide significant mechanical and thermal stability to the membrane, but are essentially non-permeable to the process stream components. These copolymer membranes of the prior art then undergo a high temperature "thermal cross-linking" to further promote molecular bonding between these copolymer chains in the final membrane composition.
For a given polymeric membrane composition, the flux across a given membrane is generally inversely proportional to the thickness of the membrane. Therefore, the cross-section of a constructed membrane is commonly very thin (on the order of about 0.1 to about 50 microns) in order to derive the selectivity benefit of the membrane while maximizing the flux characteristics of the membrane. However, for a membrane operated at constant feed composition and process conditions, the selectivity of a particular membrane composition is substantially independent of the thickness of the membrane and is principally dependent upon the compositional characteristics of the membrane.
Therefore, in order to increase the selectivity for membrane processes, new membrane compositions must be discovered that have improved selectivity characteristics. Although a high flux capacity of a membrane is desired, deficiencies in a membrane composition's flux characteristics can be overcome by increasing the active membrane area or fabricating membranes of thinner cross sections. Similar "mechanical variables" generally cannot be utilized to improve a membrane composition's inherent selectivity performance.
Additionally, some of the compounds that are utilized in the present art for the fabrication of polymeric membranes are categorized as toxic to human life and/or harmful to the environment. In particular, two of these compounds of concern, methylene dianiline ("MDA") and methylene diochloroaniline ("MOCA"), are used in the fabrication of the polyethylene adipate (PEA)/diepoxy based membranes in the prior art (see U.S. Pat. Nos. 4,990,275 and 5,550,199 to Ho et al.). The Sigma-Aldrich chemical company website classifies MDA as toxic, a possible carcinogen, and harmful to aquatic environments. Sigma-Aldrich, Chemical Name 4,4′-Methylene-13C-dianiline <http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/491500> (accessed May 8, 2006). The Sigma-Aldrich chemical company website classifies MOCA as toxic, a possible carcinogen, and extremely harmful to aquatic environments. Sigma-Aldrich, Chemical Name 4,4′-Methylene-bis(2-chloroaniline), <http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/117323>, (accessed May 8, 2006).
The use of hazardous components in the fabrication of polymeric membranes also results in higher costs of manufacturing due to increased shipping and handling costs as well as higher costs for the installation, operation and maintenance of personnel and environmental protective equipment required for the manufacture and handling of these compounds. Therefore, in addition to the potential health concerns and potential adverse environment aspects of utilizing hazardous components, there is also is an economically driven need in the industry associated with the discovery and utilization of new non-hazardous materials for the fabrication of membranes which can meet or exceed the processing capabilities, durability and performance of the polymeric membranes of the prior art.
Therefore there is a need in the industry for new membrane compositions with improved inherent selectivity characteristics. There is also a separate need in the industry for new membrane compositions utilizing materials which possess non-toxic and minimal negative environmental impact properties.

Membrane for separating aromatic and aliphatic compounds

ExxonMobil Research and Engineering Company


A reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.

An optical observation device on a high-precision optical observation satellite may be subject to vibration and disturbance inside the satellite as well as shift and blur of a pointing axis due to a change in attitude at the time of maneuvering of the satellite or depending on control accuracy of an attitude control system. In the following, the shift and blur of the pointing axis will be simply referred to as a "pointing error". A technique widely known as a measure against such a pointing error corrects the pointing error by installing a directivity control mirror inside the optical observation device and driving the mirror on the basis of a pointing error signal outputted from an image sensor. However, such a directivity control mirror has mass and moment of inertia of a mirror part, and it is known that driving the mirror at a high speed itself is a cause of vibration inside the satellite and become a factor in generating the pointing error.
Patent Literature 1 and Non Patent Literature 1 each disclose a fast steering mirror system equipped with a reactionless gimbal system that reduces disturbance caused by driving of a mirror by driving a reaction mass having the same mass property as that of the directivity control mirror in an opposite phase to that of the directivity control mirror. A reaction compensation device disclosed in Patent Literature 1 is composed of a mechanical system and a control system. The mechanical system is composed of a device with inertia and mass, and a position sensor. Such a device with inertia and mass will be hereinafter simply referred to as a "device" in some cases. The device includes a drive mechanism with a mass property provided to satisfy a functional performance of the device, a reaction mass drive mechanism disposed to be opposed to the drive mechanism, and a mounting surface provided with the drive mechanism and the reaction mass drive mechanism. The position sensor is installed to measure a relative position between a movable part and a fixed part of the drive mechanism with the mass property provided to satisfy the functional performance of the devices. The control system is provided to perform control to feed back a detection signal of the position sensor which is installed for measuring the relative position between the movable part and the fixed part of the drive mechanism with the mass property provided to satisfy the functional performance of the device, and to drive the drive mechanism with the mass property provided to satisfy the functional performance of the device in anti-phase with the reaction mass drive mechanism disposed to be opposed to the drive mechanism.

Reaction compensation device and fast steering mirror system


Techniques for reassembly-free rewriting of out-of-order data packet payload are described herein. In one aspect of the invention, in response to packets received at a network access device from a first network node destined to a second network node, the packets are stored in a buffer within the network access device if the packets need to be modified before sending the packets to the second network node. The original our-of-order packets are dropped and do not reach the second network node. The payloads of the packets stored in the buffer are modified and thereafter, the modified packets with the modified payloads are sent to the second network node. Other methods and apparatuses are also described.

Today, in many security products, pattern matching is used to prevent many types of security attacks. For example, some existing desktop virus scanning may include scanning files against certain recognizable patterns. These files usually come from mail attachments and website downloads. These desktop applications are simpler in that by the time the pattern matching is performed, the input has been all accumulated in the correct order. The situation is more complicated for gateway products, such as firewalls, attempting to match patterns for other purposes, such as deep packet inspection. Some of these products scan for patterns over Transport Control Protocol (TCP) packets. Since TCP usually breaks down application data into chunks called TCP segments, the full pattern may reside in several TCP segments. One conventional approach is to reassemble all TCP packets together into one large chunk and perform pattern matching on this chunk, similar to scanning files.
Another major problem in pattern matching is that the packets may arrive out of order. Again, using TCP as an example, the application data is broken into what TCP considers the best sized chunks to send, called a TCP segment or a TCP segment. When TCP sends a segment, it maintains a timer and waits for the other end to acknowledge the receipt of the segment. The acknowledgement is commonly called an ACK. If an ACK is not received for a particular segment within a predetermined period of time, the segment is retransmitted. Since the IP layer transmits the TCP segments as IP datagrams and the IP datagrams can arrive out of order, the TCP segments can arrive out of order as well. Currently, one receiver of the TCP segments reassembles the data if necessary, and therefore, the application layer receives data in the correct order.
One approach is to reassemble at run-time the out-of-order packets for pattern scanning purposes and letting the out-of-order packets through to reach the destination while the scanning is performed. In certain circumstances, the out-of-order packets may need to be modified before reaching the destination. There has been a lack of mechanisms to handle these situations.

Reassembly-free rewriting of out-of-order data payload


In a pump housing of a pump apparatus, a pump shaft is rotatably supported by two bearings and is connected to a pump unit. A rotary drive member is fixed to one end of the pump shaft projecting from the tip end portion of the housing. The rotary drive member includes a boss portion fixed to the one end of the pump shaft projecting from the housing, and a rim portion integral with the boss portion. The rim portion is offset from the boss portion to cover at least a portion of the tip end portion of the housing. A groove portion for receiving a drive belt is formed on the outer circumference of the rim portion. The widthwise center plane of the groove portion is located between the respective centers of the two bearings. In place of the groove portion, a tooth portion engageable with a drive gear may be formed on the outer circumference of the rim portion. Preferably, the pump unit is of a balanced vane type.

1. Field of the Invention
The present invention relates to a pump apparatus of relatively small size, and more particularly to an improvement on the structure of a pump shaft drive portion of a pump apparatus.
2. Description of the Related Art
FIG. 1 shows a conventional compact pump apparatus for supplying operation fluid to a power steering apparatus of a vehicle. In the pump apparatus, a pump shaft 2 for driving a pump unit 5 disposed within a housing 1 is supported by a ball bearing 3 and a slide bearing 4; and a pulley 9 is fixed to one end of the pump shaft 2 projecting from the housing 1. A groove portion 9a is formed on the outer circumference of the pulley 9, around which a drive belt (not shown) is wound in order to transmit rotation of an engine of the vehicle to the pump shaft 2. As a result, the pump unit 5 is operated, so that operation fluid sucked from an inlet port 6 into the interior of the pump unit 5 is discharged from an outlet port 8 via a pressure chamber 7. Generally, the pump unit 5 is a balanced-type vane pump. In such a balanced-type vane pump, a plurality of (typically, two) suction ports are provided at symmetric positions; and a plurality of (typically, two) discharge ports are provided at symmetric positions. Therefore, radial forces generated within the pump unit 5 are cancelled out, so that almost no net load acts on the pump shaft 2. Accordingly, when merely the pump unit is considered, only one end of the pump shaft 2 is required to be supported by use of a bearing having a small load capacity.
However, since a large tension is applied to the drive belt in order to prevent slippage, the following problem occurs. That is, a large tensile force W1 acts on the pump shaft 2 perpendicularly at a position corresponding to a center plane L1 of the drive belt wound around the groove portion 9a of the pulley 9. Since the center plane L1 is located on the tip end side with respect to the ball bearing 3, a moment which inclines the pump shaft 2 is produced, and a force greater than the tensile force W1 acts on the ball bearing 3. Therefore, the ball bearing 3 must have a large load capacity; and the distance between the two bearings 3 and 4 must be increased. Therefore, the size of the bearing support portion of the housing 1 increases. This problem of the bearing support portion of the housing 1 having a large size is always present even in the case where both the bearings 3 and 4 are formed of ball bearings or slide bearings, or in the case where the bearings 3 and 4 are replaced with a single long slide bearing.
FIG. 2 shows another conventional pump apparatus of a compact type. In the pump apparatus, opposite ends of a pump shaft 11 for driving a pump unit 14 are supported by slide bearings 12 and 13, which are provided within a housing 10 to be located on the front and rear sides, respectively, of the pump unit 14; and a gear 17 is fixed to one end of the pump shaft 11 projecting from the housing 10. Rotation of an engine of the vehicle is transmitted to the gear 17 via a drive gear in meshing-engagement with a tooth portion 17a of the gear 17. Thus, the pump shaft 11 is rotated to drive the pump unit 14, whereby operation fluid sucked from an inlet port 15 into the interior of the pump unit 14 is discharged from an outlet port (not shown) via a pressure chamber 16.
In the conventional pump apparatus shown in FIG. 2, since the two slide bearings 12 and 13 for supporting the opposite ends of the pump shaft 11 are attached to two members which are fixed to each other by use of bolts, aligning the center axes of the slide bearings 12 and 13 is difficult, so that smooth rotation of the pump shaft 11 cannot be expected. Therefore, the conventional pump apparatus shown in FIG. 2 has drawbacks of increased frictional torque and generation of vibration and noise.
In view of the foregoing, an object of the present invention is to provide a pump apparatus which can solve the various problems involved in conventional pump apparatuses.
To achieve the above-object, the present invention provides a pump apparatus which is driven by drive force from a drive source, comprising a housing; a bearing member provided within a tip end portion of the housing; a pump shaft rotatably supported by the bearing member, one end of the pump shaft projecting from the tip end portion of the housing; a pump unit accommodated within the housing and operated through rotation of the pump shaft; and a drive member fixed to the one end of the pump shaft projecting from the housing and adapted to transfer drive force from the drive source to the pump shaft. The drive member includes a drive force input portion to which the drive force is transferred from the drive source. The center of the bearing member in the axial direction of the pump shaft coincides with-the center of the drive force input portion in the axial direction of the pump shaft.
Preferably, the drive member includes a boss portion fixed to the one end of the pump shaft projecting from the housing, and a rim portion integral with the boss portion, the rim portion being offset from the boss portion to cover at least a portion of the tip end portion of the housing; and the drive input portion is formed on the outer circumference of the rim portion.
Preferably, the bearing member consists of two bearings disposed adjacent to each other; and the center of the drive force input portion in the axial direction of the pump shaft is located between the respective centers of the two bearings in the axial direction of the pump shaft.
The drive force input portion may be a groove portion which is engaged with a drive belt extended between and wound around the groove portion and a pulley of the drive source. In this case, the center of the groove portion in the axial direction of the pump shaft is located between the respective centers of the two bearings in the axial direction of the pump shaft.
The drive force input portion may be a tooth portion which is in meshing-engaged with a drive gear of the drive source. In this case, the center of the tooth portion in the axial direction of the pump shaft is located between the respective centers of the two bearings in the axial direction of the pump shaft.
Preferably, the pump unit is a vane pump. More preferably, the vane pump is a balanced-type vane pump having a plurality of suction ports disposed symmetrically with respect to the pump shaft and a plurality of discharge ports disposed symmetrically with respect to the pump shaft.

Pump apparatus having drive force input portion aligned with pump shaft bearing member


The invention relates to a wiper blade (10) of flat bar design composed of a wiper strip (14) comprising a wiper lip (18) connected to a head strip (22) via a tilting web (20), at least one pre-bent, elastic spring rail (46, 52, 54) acting as a supporting element, a connecting element (12) and a spoiler (32) having a flowing profile (34) and a holding profile (38), wherein the spoiler (32) includes in the flowing profile (34) thereof at least one longitudinal channel (44, 48, 50) with a spring rail (46, 52, 54), and the holding profile (38) thereof has at the longitudinal sides thereof free branches (42) opposite each other, directed inward, engaging into respective longitudinal grooves (24) of the head strip (22). According to the invention, the head strip (22) is free of spring rails, and in particular no spring rail (46, 52, 54) will contact the head strip (22).

The invention is based on a wiper blade of flat bar design.
DE 10 2006 020 524 A1 discloses a wiper blade of the type in question. The wiper strip of said wiper blade has a relatively wide head strip in which a longitudinal channel is provided for receiving a spring rail which is approximately rectangular in cross section. The spring rail together with part of the head strip is surrounded by a retaining profile of a spoiler, the mutually facing, free limbs of which retaining profile engage in the head strip in lateral longitudinal grooves below the spring rail. On that side of the spring rail which faces away from a vehicle window, a further longitudinal channel for receiving a second spring rail, which is likewise rectangular in cross section, is arranged in the spoiler. A further longitudinal channel serving to save on material is provided thereabove in the region of an approach flow profile toward a longitudinal ridge of the spoiler. In order to facilitate the installation, the longitudinal channel provided in the spoiler and intended for receiving the second spring rail has a longitudinal gap toward the head strip. The spoiler is produced from a softer material in the region of the approach flow profile than in the region of the retaining profile thereof, wherein the separating surface runs below the second spring rail toward the head strip.


A process for preparing isosorbide ethoxylate di(meth)acrylate by transesterifying alkyl (meth)acrylate with isosorbide ethoxylate, comprising the steps of:    (i) ethoxylating isosorbide to give isosorbide ethoxylate,    (ii) reacting alkyl (meth)acrylate with isosorbide ethoxylate in the presence of potassium phosphate as catalyst and a stabilizer and in the presence of an azeotroping agent which forms an azeotrope with the alcohol bound in the alkyl (meth)acrylate,    (iii) continuously distilling off the azeotrope of azeotroping agent and alcohol, wherein steps (ii) and (iii) are conducted simultaneously until the isosorbide ethoxylate has been essentially fully converted,    (iv) removing the catalyst from the product mixture comprising isosorbide ethoxylate di(meth)acrylate,    (v) distilling unconverted alkyl (meth)acrylate and azeotroping agent out of the product mixture.

E2BADMA (dimethacrylate of bisphenol A alkoxylated with 2 ethylene oxide units in each case) and E3BADMA (dimethacrylate of bisphenol A alkoxylated with 3 ethylene oxide units in each case) are bisphenol A-based dimethacrylates which are used as crosslinkers, for example in coatings and mixtures for drillholes. They are notable for a rapid reaction time which leads to partial load-bearing capacity of 2-pack mixtures even after a short time and attainment of the final tensile strength after a few hours. In addition, they have a high polymer density with a very good cohesion/adhesion ratio, good crystallization resistance with simultaneously low shrinkage and a low tendency to embrittlement, and high wetting power in order to assure good creeping capacity in capillary cracks.
DE 41 31 458 A1 discloses two-pack adhesive compositions for chemical securing technology, comprising a synthetic resin comprising the di(meth)acrylate of an alkoxylated bisphenol and a hardener for the synthetic resin.
For particular applications, bisphenol A-free crosslinkers having a similar profile of properties are being sought.
Isosorbide is a diol based on renewable raw materials and, in structural terms, is an alternative to bisphenol A, since it has a similarly rigid base structure.
One means of preparing di(meth)acrylates from isosorbide is the esterification of isosorbide with (meth)acrylic acid or the transesterification of methyl acrylate, ethyl acrylate or methyl methacrylate with isosorbide in the presence of suitable catalysts. Both OH groups of isosorbide are secondary OH groups having comparatively low reactivity, and the relative reactivities of the two OH groups are additionally very different. Thus, incomplete conversion is to be expected.
DE 2 317 226 A1 discloses a method of preparing (meth)acrylic esters from a mixture of C10-C18 alkanols by transesterification of methyl (meth)acrylate in the presence of titanium alkoxide as catalyst and 2,6-di-tert-butylparacresol (TBC) as stabilizer. This method is carried out in the presence of activated carbon. Once the reaction has ended, water is added to hydrolyze the titanium alkoxide to titanium hydroxide/oxide which adsorbs onto the activated carbon. The solid is filtered off and the reaction product is subjected to a steam distillation.
WO 2009/080380 discloses a process for preparing methacrylates of C6-C22 alcohols by transesterifying methyl (meth)acrylate with the appropriate alcohols in the presence of titanium alkoxide as catalyst. In example 1, methyl methacrylate is reacted with 2-ethylhexanol in the presence of hydroquinone monomethyl ether (MEHQ) as stabilizer and tetraisopropyl titanate as catalyst. An azeotropic mixture of methanol/methyl methacrylate is distilled off. After distilling off unconverted methyl methacrylate, the catalyst-comprising 2-ethylhexyl methacrylate is subjected to a purifying distillation under reduced pressure (about 30 mbar). This affords 2-ethylhexyl methacrylate in 99.4% purity.

Process for preparing isosorbide ethoxylate di(meth)acrylate


A telephony communication device is capable, upon an election by a user, of transmitting a defer answer signal in response to receiving notification of an incoming call. The defer answer signal causes the telephony infrastructure equipment to place the calling party on hold and play a voice message to the calling party requesting that the party remain on hold and preferably informing the calling party that the called party will be able to accept the call within a predetermined time. Upon the called party becoming available to accept the incoming call, the called party retrieves the waiting call by sending a connect call signal from subscriber's communication device.

This invention is generally directed to telecommunication systems, and is more specifically directed to providing the called party with additional options for handling an incoming call where it is not desired to answer the call immediately.
Telephone subscribers may receive an incoming telephone call at a time that is inconvenient to answer. For example, the subscriber may be engaged in an in-person conversation with another and does not desire to interrupt the current conversation to answer an incoming call. This situation is especially common for wireless subscribers that normally carry a cellular telephone. Assuming that the subscriber utilizes a voicemail service, the unanswered incoming call could be diverted to the subscriber's voicemail service giving the caller an opportunity to leave a message. However, this does not satisfy a need for an interactive conversation.
A common situation exists in which the called party does not wish to immediately answer an incoming call, but would be able to answer the incoming call within a short time, e.g. one or two minutes. Such a "deferred" answer may be preferable to both the calling and called parties. In many situations the ability to employ a defer answer may provide efficiencies. It eliminates the called party from having to retrieve a voicemail message and attempting to reach the other party by initiating a new call. From the calling party's perspective, it eliminates the uncertainty of when the called party will be available to retrieve a voicemail message and the uncertainty of possibly being unavailable to accept the return call.
Telecommunication systems offer wireless and wireline users the ability to subscribe to call waiting service. This service provides a subscriber engaged in a telephone conversation with another party with an alert indicating that the subscriber has another incoming call. The basic service provides an audible tone to the called party to indicate another incoming call is waiting. An advanced form of the call waiting service provides the called party with the telephone number and/or name of the call waiting party utilizing incoming call identification (CID). The called party after being alerted of the call waiting call can ignore the incoming call and continue the conversation with the other party, or can put the current party on hold and answer the incoming new call. Although the called party can return to the conversation with the other party after electing to answer the incoming new call, it is an interruption and often times an annoyance to both the other party and the called party. A defer answer capability would permit the called party to handle a call waiting caller without having to disrupt the conversation with the other party. Thus, there exists a need for a defer answer capability.

Incoming call control by the called party


An apparatus for testing an optical test piece comprising an interferometer for emitting an incident light beam. The apparatus includes a first reflective optic that receives the incident beam and produces a first reflected beam by focusing and expanding the received incident beam. The apparatus also includes a second reflective optic that receives and collimates the first reflected beam and outputs the collimated beam toward the optical test piece. Both the first and the second reflective optics are fixed to their respective positions relative to a thermally insensitive platform and the optical test piece is docked to the thermally insensitive platform and can be removed.

Interferometry techniques are used for testing surfaces of optical elements. In one interferometry test configuration, known as a Fizeau interferometer, a plane parallel wavefront is used to test flat optics. There are several such devices available from manufacturers and most commonly have a 4 inch diameter aperture. When a measurement is required on a larger flat, it is often accomplished by coupling one of these common 4 inch Fizeau interferometers to a beam expander.
Commercially available beam expanders are typically made from large refractive elements. One of the purposes of using refractive optics in interferometry techniques is to guide light through the interferometer system. However, refractive optical elements tend to produce beam scattering which degrades the quality of the interferometer output measurements. Moreover, functionalities of refractive optics are dependent on the wavelength of operation. As such, the interferometer system needs to be adjusted for a specific wavelength every time the operational wavelength is changed.

System and method for setting up secondary reflective optic


Interruption of a reception signal is achieved by placing a first low noise amplifier into the sleep state, and short-circuiting a shunt switch provided between differential input terminals of a second low noise amplifier during a DC offset canceling period. Further, an antenna switch is switched to a circuit system where DC offset canceling is not performed for preventing the input of the reception signal to a circuit system where DC offset canceling is performed.

1. Field of the Invention
The present invention relates to a wireless communication receiver circuit of a direct conversion system. In particular, the present invention relates to a wireless communication receiver circuit which has a DC offset canceling function.
2. Description of Related Art
Conventional signal processing systems used in wireless communication for cellular phones or the like include a superheterodyne system. In such a superheterodyne system, a process of downconverting of a reception signal to an intermediate frequency is temporarily required, and thus, the circuit scale is large.
In recent years, as a solution of this problem, a direct conversion system has been developed wherein downconversion into the intermediate frequency is not necessary. However, in the direct conversion system, the output of the DC offset to the next stage is amplified undesirably when a DC offset is present in a reception signal path.
A solution of this problem presents a DC offset canceling method. A receiver circuit carrying out this method has a structure, for example, as shown in FIG. 3. Specifically, the receiver circuit includes a duplexer 101, a first low noise amplifier 102, a band pass filter 103 comprising a SAW (surface acoustic wave) filter, a second low noise amplifier 104, demodulators 105_1, 105_2 comprising mixers, a local oscillator 106, a control logic circuit 107, gain control amplifiers 108_1, 108_2, DC offset canceling circuits 109_1, 109_2, lowpass filters 110_1, 110_2, and a base band block 111. Posterior the demodulators 105_1, 105_2, the circuit is separated into two signal paths for carrying out the signal processes of the in-phase component and the quadrature component separately.
In the receiver circuit having the above structure, the DC offset canceling circuits 109_1, 109_2 respectively connect the input ends to the output ends of the gain control amplifiers 108_1, 108_2. The DC offset canceling circuits 109_1, 109_2 calibrate the DC offset at the input portions of the gain control amplifiers 108_1, 108_2.
The control logic circuit 107, being connected to a local oscillator 106, outputs a frequency control signal for controlling the oscillating frequency. The frequency control signal, being inputted to the local oscillator 106, defines the oscillating frequency in the local oscillator 106. At the time of starting the DC offset canceling operation, the control logic circuit 107 outputs a DC offset canceling signal. The DC offset canceling signal is inputted to the DC offset canceling circuits 109_1, 109_2, and the DC offset canceling operation by the DC offset canceling circuits 109_1, 109_2 starts.
FIG. 4 shows a specific example of a DC offset canceling circuit disclosed in Japanese Laid-Open Patent Publication No. 2001-211098. As shown in FIG. 4, in the DC offset canceling circuit 109_1, the DC offset component at the output of the gain control amplifier 108_1 is read and digitalized by an AD converter 401, and inputted to a control circuit 402. Thereafter, based on a digital signal corresponding to the inputted DC offset component, the control circuit 402 outputs a calibration signal to the DA converter 403 as a digital signal for canceling the DC offset. The DA converter 403 converts the inputted calibration signal to an analog signal and outputs to the gain control amplifier 108_1. Thus, the DC offset voltage at the output of the gain control amplifier 108_1 is calibrated, and the DC offset is cancelled.
As shown in FIG. 4, at the time of canceling the DC offset, the DC offset is detected at the output portion of the gain control amplifier 108_1. When a reception signal is present at the time of detecting the DC offset, an AC voltage is superimposed on the offset potion of the DC voltage. Therefore, during the DC offset canceling operation period, it is not possible to detect only the DC offset if the reception signal is present. Therefore, the accuracy in the DC offset canceling operation is low.

Matsushita Electric Industrial Co., Ltd.


A loop antenna adapted for a communication device is provided. The loop antenna includes a feed, a ground, a circular loop, at least one first tuning element, and at least one second tuning element. The circular loop is connected to the feed and the ground. The first tuning element is extended from the circular loop and corresponds to a first frequency band. The second tuning element is extended from the circular loop and corresponds to a second frequency band. Bandwidths of the first frequency band and the second frequency band of the loop antenna are changed by adjusting the first tuning element and the second tuning element, respectively.

1. Field of the Invention
The invention relates to a loop antenna; more particularly, the invention relates to a loop antenna with an adjustable bandwidth.
2. Description of Related Art
Research and development of communication devices are often conducted according to the market demands, and different types of the communication devices are presented to the public step by step. For instance, since a wireless fidelity (Wi-Fi) function has already become indispensable for normal users, a new communication device featuring Wi-Fi is often presented at first; in a later stage, the same type of communication device that further supports global system for mobile communication (GSM) or long term evolution (LTE) may then be developed. In theory, when the device featuring Wi-Fi is designed, the space for placing antennas with low frequency bands (e.g., GSM or LTE) may be kept in advance, so as to save the time and costs on subsequent re-molding and re-design.
The space for placing antennas with low frequency bands may sometimes not be kept in some types of devices. In this case, it is rather difficult for a designer to design antennas. For instance, the space capable of placing an antenna may have other circuits or metal and is not completely available, and a printed circuit board with high-speed signal lines or any other metal devices may be extremely close to the antenna, e.g., the distance therebetween may be less than 5 mm. Under these circumstances, the types of antennas become crucial, and a loop antenna, for instance, is not apt to be affected by surroundings.
Generally, the length of the antenna is determined according to the minimum frequency required by the antenna. For instance, if the desired frequency is 824 MHz, the required wavelength is approximately 0.364 meters because the light velocity (3×108 meters/seconds) is calculated by multiplying the frequency of light (8.24×108 MHz) by the wavelength. Since the required length of the loop antenna is half the wavelength, i.e., 0.182 meters, the required length of the loop antenna in the limited space within the communication device needs to satisfy 0.182 meters. As a result, the loop antenna within the communication device is often designed to be bent or surround the insulation elements in the communication device, such that the loop antenna may occupy less space.
FIG. 1 is a schematic view illustrating a conventional loop antenna. With reference to FIG. 1, the conventional loop antenna 10 includes a feed 12, a ground 14, and a circular loop 16 that is connected to the feed 12 and the ground 14. After the sample loop antenna 10 is made, the circular loop 16 can be barely adjusted. Even though the bandwidth corresponding to the conventional loop antenna 10 is different from the originally designed bandwidth, it is rather difficult to rectify this deficiency.


A rigid glove has openings at the ends of the fingers such that the ends of the fingers from the most distal joint to the end protrude therefrom. The fingers may be flexed as an exercise. Caps of varying resistance may also be applied to the ends of the glove's fingers.

1. Field of the Invention
The present invention relates to an exercise device for strengthening the most distal phalanges, the digits. Specifically, the exercise device allows the wearer to isolate and strengthen the muscles that control the digits.
2. Prior Art
Sports at all levels are highly competitive. Athletes are constantly practicing and exercising to improve their ability in a particular sport. Countless exercise devices have been designed to isolate and improve the strength of both muscle groups and individual muscles. While most attention has focused on the larger muscle groups of the legs, arms and trunk, little attention has been given to exercising various muscles that give strength to the fingers. This is somewhat surprising considering that most sports require the handling of a ball or other instrument in which a strong grip is important. The most important part of an athlete's grip lies in the digits, the most distal phalanges of the fingers. The ends of the fingers are vital for gripping a basketball or football, as well as many other sport objects. While many glove devices have been designed, none allow the wearer to focus on strengthening his or her digits.
Cronin (U.S. Pat. No. 4,706,658) discloses a splint across the palm and includes extensions for supporting the fingers and perhaps the thumb. Although it discloses a somewhat rigid glove optionally having flexible joints, it does not disclose a rigid glove that only allows flexing of the most distal joints.
Martel et al. (U.S. Pat. No. 5,498,234) discloses a hand and arm support. The front edge includes spaced finger holes, while the rear edge defines an opening for a hand. The glove body is made from a thin lightweight elastic spandex material. This patent only discloses use of an elastic material.
Stephens (U.S. Pat. No. 5,604,933) discloses a hand and wrist restraint for a patient. This glove is made of soft material, such as cotton, and therefore does not disclose the present invention. Eck (U.S. Pat. No. 5,746,707) discloses a wrist and two digit restraining device for the treatment of carpal tunnel syndrome. The device comprises a palmar brace having a wrist support receiving the wrist of a patient, a portion supporting the heel and palm of the patient's hand and terminating at the base of the second, third and forth fingers of the hand. This device does not allow for flexing of the digits.
Reich (U.S. Pat. No. 5,794,265) discloses a garment sleeve adapted to receive the arm and hand of a user and so constructed that the palm of the user is protected, with finger movement unrestricted, as the hand extends out of the distal end of the sleeve and at the same time the distal end is sealed against entry of wind, air, rain and the like. This patent allows free movement of the fingers.
Gunn (U.S. Pat. No. 5,829,057) discloses an article which incorporates fabrics or chemicals having a low coefficient of friction either overall or in specific areas of the apparel. This device does not disclose a rigid glove.
Robinson (U.S. Pat. No. 6,010,473) discloses a remedial hand wear article comprising a glove for comfortably fitting onto a hand of an individual, an enclosure superimposed on a top side of the glove and permanently attached thereto, and a substantially rigid member positioned within the enclosure and operably associated with a finger of the individual to position that finger in a desired posture. The glove portion of the hand wear article provides comfort to the user while also serving to lessen the noticeability of any hand or finger grotesqueness. A proximal knuckle of at least one finger is blocked to prevent hyperextension, while the proximal knuckle and the distal knuckles of the finger are capable of full anatomical finger flexure.
Chow (U.S. Pat. No. 6,475,174) discloses a sleeve having a splint to partially immobilize the thumb side of a hand. It does not disclose a rigid glove and allows only movement about the most distal knuckle.
Chow (U.S. Pat. No. 6,496,984) discloses a sleeve, including a splint very similar to the previous patents. The only substantial difference is in the location of the rigid splint. Like the previous patent, it does not disclose the rigid glove similar to the present invention.
Flores (U.S. Pat. No. 6,539,550) discloses a set of three driving gloves, each having a different length to be worn by a driver. Each glove has a varying length with finger portions cut away to allow for greater flexibility when driving. This patent discloses cut-away finger portions of the glove so that the fingers may be flexed.
Williams (U.S. Pat. No. 6,571,397) discloses protective garments, such as gloves and socks and the method of making the same that are comfortable to wear and at the same time provide a high degree of protection to the user against exposure to various chemical vapors, and hazardous agents including noxious gases. This invention does not disclose the use of rigid gloves.
None of these patents disclose a device suitable for flexing the digits only and keeping all of the joints in the hand stationary. They are therefore not suitable for exercising and strengthening the ends of the fingers.
It is therefore desirable to provide a device for exercising the most distal phalanges, or digits.
It is also desirable to provide a device for isolating and flexing only the digits while maintaining the rest of the hand in a stationary position.


An object is to enhance direct-current insulating performance of a gas-blast circuit breaker. The gas-blast circuit breaker includes: a pair of main contacts disposed in a gas tank to face each other and configured to operate for opening and closing a circuit; a pair of arc contacts disposed to face each other and configured to operate for opening and closing the circuit, the arc contacts being disposed coaxially with the main contacts at locations close to the centers of the main contacts, respectively; and an elastic electrically conductive material disposed on an outer surface of an insulating nozzle facing an inner surface of one of the main contacts.

Recently, electric power systems have been made to deal with higher voltage and larger current. In order to achieve the required circuit breaking performance, gas-blast circuit breakers with a larger capacity have been developed.
With reference to FIG. 9, the following will describe a schematic configuration of a conventional gas-blast circuit breaker and how the conventional gas-blast circuit breaker operates for interrupting electric current. The gas-blast circuit breaker is accommodated in a gas tank (not illustrated) filled with insulating gas. Normally, a driving-side arc contact 1 on an operation device side and a driven-side arc contact 2 on a side facing the operation device are electrically connected to each other, and a driving-side main contact 3 and a driven-side main contact 4 are electrically connected to each other. However, when an accident happens and a command to open the circuit is given, the driving side is actuated by the operation device (not illustrated) via a puffer shaft 6 and an insulating rod (not illustrated), which causes a transition to a state where the driving-side arc contact 1 on the driving side and the driven-side arc contact 2 on the driven side are physically separated from each other and the driving-side main contact 3 and the driven-side main contact 4 are physically separated from each other.
Even after the contacts are separated from each other, electric current still flows between the driving-side arc contact 1 and the driven-side arc contact 2, which causes generation of an arc. The gas-blast circuit breaker blows high-pressure insulating gas to the arc to extinguish the arc. While the driving side is operating, insulating gas in a puffer chamber 9 is compressed by a puffer piston 8, and is blown into an arc space 10, so that the arc is extinguished. At the time of the extinguishment of the arc, hot gas is generated, which flows through a driving-side exhaust gas guide and then is discharged into a tank. To increase the pressure of the insulating gas in the puffer chamber 9 is important to enhance the circuit breaking performance for extinguishing the arc.
Recently, for the purpose of reducing operation power, a heat puffer type gas-blast circuit breaker has been developed that utilizes arc heat to achieve a pressure of gas to be blown to arc. Meanwhile, for the purpose of enhancing the circuit breaking performance, a bidirectional driving type gas-blast circuit breaker has been proposed that drives a driven-side electrode, which has been fixed in the conventional configuration, in a direction opposite to a driving direction of a driving-side electrode.
With reference to FIG. 1, the following will explain how the bidirectional driving type gas-blast circuit breaker operates. A driving side and a driven side are coupled to each other by a driving-side coupling rod 21 via an insulating nozzle 5 and a lever 22. The lever 22 is turnably fixed to a guide 27 with a lever fixing pin 23. The lever 22 is coupled to a driven-side rod 26 with a driven-side pin 25. Pulling with an operation device toward the driving side causes the whole of the driving-side coupling rod 21, which is connected to the insulating nozzle 5, to move toward the driving side. In response to the movement of the driving-side coupling rod 21, the lever 22 turns around the lever fixing pin 23, whereby the driven-side rod 26 and a driven-side arc contact 2 move, via the driven-side pin 25, in a direction away from the driving side.
In addition, as a result of an increase in pressure of the gas to be blown, internal pressures applied to a puffer cylinder 7 and the insulating nozzle 5 have been increased. The insulating nozzle 5 is often made of an insulating material excellent in heat resistance and insulating property. However, the insulating nozzle 5 is weak in mechanical strength, and thus may potentially be deformed due to an increase in pressure that occurs during circuit breaking operation. According to PTL 1, the insulating nozzle 5 has an outer circumferential surface covered with an insulating material excellent in insulating property. In this manner, PTL 1 reinforces the insulating nozzle 5 without giving any effect on the electric field. The mechanical strength may alternatively be enhanced by increasing a radial thickness of the insulating nozzle 5 or by covering the outer circumferential surface of the insulating nozzle 5 with a metallic component having an excellent mechanical strength. The outer circumferential surface of the insulating nozzle 5 may be covered with a metallic component excellent in mechanical strength in the following manner. That is, the driving-side main contact 3 may be designed to have an inner diameter that allows an inner surface of the driving-side main contact 3 to be in contact with the outer surface of the insulating nozzle 5. This configuration can enhance the strength of the insulating nozzle 5 without adding any component, and thus is advantageous in terms of cost. Ideally, the insulating nozzle 5 may be designed to have an outer diameter identical to an inner diameter of the driving-side main contact 3. However, considering an allowance, ease of assembling, and the like, the insulating nozzle 5 should be designed to have an outer diameter with a negative allowance, and the driving-side main contact 3 should be designed to have an inner diameter with a positive allowance. This configuration may potentially create a minute gap. In addition, the insulating nozzle 5, which is made of a resin, and the driving-side main contact 3, which is made of a metal, have different coefficients of thermal expansion, and therefore the minute gap 14 may be increased or reduced.
In the circuit breaker of the bidirectional driving type, the driving side and the driven side are connected to each other via the driving-side coupling rod 21 even while the circuit is opened. Accordingly, the voltage across the electrodes is applied to the insulating nozzle 5. The gas-blast circuit breaker has various interruption duties. When the gas-blast circuit breaker interrupts leading small current, such as charging current in a no-load transmission line and/or a capacitor for power adjustment, direct-current voltage may be applied to one side of the circuit breaker. In order to deal with this, the bidirectional driving type gas-blast circuit breaker is configured such that the electrodes are connected to each other via an insulator. In the gas-blast circuit breaker in which the electrodes are connected to each other via the insulator, a dielectric constant is dominant in an alternating-current electric field, and an electric conductivity is dominant in a direct-current electric field.


The present invention is directed to a purified polyalkylsiloxane composition having a boiling point, under atmospheric conditions, of less than about 250.degree. C. and containing high boiling impurities, including siloxanes and silanol-terminated siloxanes, that have boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of less than 14 ppm. The present invention is further directed to a method of producing a purified polyalkylsiloxane composition, having a boiling point, under atmospheric conditions, of less than about 250.degree. C., by distilling a polyalkylsiloxane starting material containing high boiling impurities having boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of at least 14 ppm, under conditions effective to produce a purified polyalkylsiloxane composition having a boiling point under atmospheric conditions of less than about 250.degree. C., and containing high boiling impurities, having boiling points, under atmospheric conditions, of greater than about 250.degree. C., in a total concentration of less than 14 ppm. In preferred embodiments, low boiling components (including silanols and preferably also hexamethylcyclotrisiloxane) are reduced to less than about 100 ppm. The present invention is further directed to a method of producing fused silica glass by conversion of the purified polyalkylsiloxane composition.

Various processes are known in the art that involve the production of metal oxides from vaporous reactants. Such processes require a feedstock solution, a means of generating and transporting vapors of the feedstock solution (hereafter called vaporous reactants) and an oxidant to a reaction site, and a means of catalyzing oxidation and combustion coincidentally to produce finely divided, spherical aggregates, called soot. This soot can be collected in any number of ways, ranging from a collection chamber to a rotating mandrel. It may be simultaneously or subsequently heat treated to form a non-porous, transparent, high purity glass article. This process is usually carried out with specialized equipment having a unique arrangement of nozzles and burners.
Much of the initial research that led to the development of such processes focused on the production of bulk fused silica. Selection of the appropriate feedstock was an important aspect of this work. Consequently, it was, at that time, determined that a material which could generate vapor pressure of 200-300 Torr at temperatures below 100.degree. C. would be useful for making such bulk fused silica. The high vapor pressure of silicon tetrachloride (SiCl.sub.4) suggested its usefulness as a convenient vapor source for soot generation and launched the discovery and use of a series of similar chloride-based feedstocks. This factor, more than any other, is responsible for the presently accepted use of SiCl.sub.4, GeCl.sub.4, POCl.sub.3, ZrCl.sub.4, TiCl.sub.4, and BCl.sub.3 as vapor sources, even though these materials have certain chemically undesirable properties. Returning to SiCl.sub.4, it has been the industry standard over the years for the production of high purity silica glasses. As disclosed in U.S. Pat. No. 3,698,936, one of several reactions may take place to produce high purity fused silica via oxidation of SiCl.sub.4 ; namely: EQU SiCl.sub.4 +O.sub.2 --SiO.sub.2 +2Cl.sub.2, (1) EQU SiCl.sub.4 +2/3O.sub.3 --SiO.sub.2 +2Cl.sub.2, or (2) EQU SiCl.sub.4 +2H.sub.2 O--SiO.sub.2 +4HCl, (3)
whereby burners or jet assemblies are utilized in feeding the reactant gases and vapors to a reaction space. It should be noted that reaction (2) rarely occurs or is used. There are inherent economic disadvantages to each of these reactions. Moreover, these reactions, which oxidize SiCl.sub.4 through pyrolysis and hydrolysis, have the disadvantage of producing noxious and corrosive hydrochloric acid or chlorine by-products.
While the first two reactions occur theoretically, an auxiliary fuel is generally needed to achieve pyrolytic temperature. As to the third reaction, the hydrolysis of SiCl.sub.4 results in the formation of hydrochloric acid (HCl), a by-product that is detrimental not only to many deposition substrates and to reaction equipment but also is harmful to the environment. Emission abatement systems have proven to be very expensive due to down-time, loss, and maintenance of equipment caused by the corrosiveness of HCl. The handling and disposal problems of the HCl by-product notwithstanding, the third reaction, hydrolysis of SiCl.sub.4, tends to be the preferred commercial method of producing fused silica for economic reasons.
Though hydrolysis of SiCl.sub.4 has been the preference of industry for producing high purity fused silica over the years, the enhanced global sensitivity to environmental protection has led to more strict government regulation of point source emissions, prompting a search for less environmentally pernicious feedstocks. Point source emission regulations require that HCl, the by-product of hydrolyzing SiCl.sub.4, be cleansed from exhaust gases prior to their release into the atmosphere. The economic consequences of meeting these regulations have made commercial production of fused silica from halide-based feedstocks less attractive to industry.
As an alternative, high purity fused quartz or silica has also been produced by thermal decomposition and oxidation of silanes. Silanes are silicon-containing compounds analogous to hydrocarbons in which silicon is substituted for carbon. (For clarity, we note that siloxanes are compounds having an oxygen atom bonded to two silicon atoms, viz. Si--O--Si.) However, thermal decomposition and oxidation requires taking safety measures in handling because of the violent reaction that results from the introduction of air into a closed container of silanes. Silanes react with carbon dioxide, nitrous oxide, oxygen, or water to produce high purity materials that are potentially useful in producing, among other things, semiconductor devices. However, silanes have proven to be much too expensive and reactive to be considered for commercial use except possibly for small scale, extremely high purity applications.
A number of patents describe the production of high purity metal oxides, particularly fused silica, from a chloride-based feedstock. These patents disclose equipment with a number of burner arrangements and feedstock delivery systems to achieve oxidation of a metal chloride through flame hydrolysis or pyrolysis. Illustrative of this is U.S. Pat. No. 4,491,604 to Lesk et al., where trichlorosilane, dichlorosilane, and silicon tetrachloride are flame hydrolyzed to form soot, and U.S. Pat. No. 3,666,414 to Bayer, where silicon halides such as trichlorosilane are flame hydrolyzed. In similar processes, U.S. Pat. Nos. 3,486,913 to Zirngibl ("Zirngibl") and 2,269,059 to McLachlan ("McLachlan") teach oxidation of halides. Volatilized inorganic halide components such as TiCl.sub.4, CrCl.sub.3, CrO.sub.2 Cl.sub.2, SiCl.sub.4, AlCl.sub.3, ZrCl.sub.4, FeCl.sub.2, FeCl.sub.3, ZnCl.sub.2, or SnCl.sub.4 that are oxidized with air, steam, or oxygen are employed in Zirngibl, while silicon halides, ethyl silicate, methyl borate, TiCl.sub.4, AlCl.sub.3, and ZrCl.sub.4 are used by McLachlan.
U.S. Pat. No. 3,416,890 to Best et al. discloses a process for preparing finely-divided metal or metalloid oxides by the decomposition of a metal or metalloid perhalide in a flame produced by the combustion of an oxidizing gas and an auxiliary fuel, such as carbon disulfide, carbon selenide sulfide, thiophosgene, or other hydrogen-free compounds containing sulfur bonded directly to carbon.
U.S. Pat. No. 2,239,551 to Dalton discloses a method of making glass by decomposing a gaseous mixture of glass-forming compounds in a flame of combustible gas. The mixture is used in the formation of anhydrous oxides of silicon, aluminum, and boron. Decomposable compounds such as ethyl or methyl silicate, trichlorosilane, and silicon tetrafluoride may be substituted for silicon tetrachloride; methyl borate or boron hydride may be substituted for boron fluoride, etc.
U.S. Pat. No. 2,326,059 to Nordberg details a technique for making silica-rich ultra-low expansion glass by vaporizing tetrachlorides of Si and Ti into the gas stream of an oxy-gas burner, depositing the resultant mixture to make a preform, vitrifying the preform at 1500.degree. C. to make an opal glass, and firing the opal preform at a higher temperature to cause it to become transparent.
U.S. Pat. No. 2,272,342 to Hyde discloses a method of producing glass articles containing vitreous silica by vaporizing a hydrolyzable compound of silicon such as silicon chloride, trichlorosilane, methyl silicate, ethyl silicate, silicon fluoride, or mixtures thereof, using a water bath. The silicon compound vapor is hydrolyzed by water vapor in the flame of a burner, and the resulting amorphous oxide is collected and subsequently sintered until a transparent glass results.
U.S. Pat. No. 4,501,602 to Miller et al. describes the production of particulate metal oxide soot utilizing .beta.-diketonate complexes of metals from Groups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, and the rare earth series of the Periodic Table.
Also cited in the art are several patents where silane compounds have been used in producing high purity fused silica.
Japanese Patent Application No. 90838-1985 to Okamoto et al., discloses a method of doping quartz glass by utilizing an ester silane expressed by the general formula R.sup.1.sub.n Si(OR.sup.2).sub.4-n and one or more dopants defined by the formulas Ge(OR.sup.3).sub.3, B(OR.sup.3).sub.3, and PH.sub.3, where R.sup.1 is a hydrogen atom, methyl or ethyl group; R.sup.2 is a methyl or ethyl group; R.sup.3 is an univalent hydrocarbon group; and n is an integer ranging between 0 and 4. A great many organometallic compounds are disclosed, including methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, tetramethoxysilane, methyltriethoxysilane, and tetraethoxysilane.
U.S. Pat. No. 3,117,838 to Sterling describes a method of producing very pure fused quartz or silica by the combined thermal decomposition and oxidation of silanes, where either carbon dioxide, nitrous oxide, or water vapor and a silane are fed into a burner or torch jet and the flame is allowed to impinge on a carbon substrate upon which silica is deposited.
U.S. Pat. No. 4,810,673 to Freeman discloses a method of synthesizing high quality silicon oxides by chemical vapor deposition of a source gas mixture which includes a halogenated silane component and an oxygen source, namely, dichlorosilane and nitrous oxide.
U.S. Pat. No. 4,242,487 to Hasegawa et al. discloses a method of producing a heat resistant, semi-inorganic compound that is useful as a raw material for making various heat-resistant materials by reacting an organoborosiloxane compound with at least one of the group of aliphatic polyhydric alcohols, aromatic alcohols, phenols, and aromatic carboxylic acids at 250.degree. C. to 450.degree. C. in an inert atmosphere.
As is clear from the preceding discussion, it is highly desirable for both economic and environmental reasons to find halide-free silicon compounds to replace the silicon halide feedstocks typically used to produce high purity silica glass. Such halide-free starting materials would produce carbon dioxide and water, rather than noxious and corrosive Cl.sub.2 and HCl, as by-products of the glass-making process.
U.S. Pat. No. 5,043,002 to Dobbins et al., the disclosure of which is hereby incorporated by reference, discloses the usefulness of polymethylsiloxanes, in particular, polymethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane in a method of making fused silica glass. The method can be applied to the production of a non-porous body of silica glass doped with various oxide dopants and for the formation of optical waveguide fibers. U.S. Pat. No. 5,043,002 to Dobbins et al. also discloses the use of hexamethyldisiloxane; see also reference to hexamethyldisiloxane in Japanese Patent Application No. 1-138145.
U.S. Pat. No. 5,152,819 to Blackwell et al., the disclosure of which is hereby incorporated by reference, describes additional halide-free silicon compounds, in particular, organosilicon-nitrogen compounds having a basic Si--N--Si structure, siloxasilazones having a basic Si--N--Si--O--Si structure, and mixtures thereof, which may be used to produce high purity fused silica glass without the concomitant generation of corrosive, polluting by-products.
Although use of halide-free silicon compounds as feedstocks for fused silica glass production, as described in U.S. Pat. Nos. 5,043,002 and 5,152,819, avoids the formation of HCl, some problems remain, particularly when the glass is intended for the formation of optical waveguide fibers. Applicants have found that the presence of high boiling impurities in, for example, a polyalkylsiloxane feedstock, can result in the formation of gel deposits in the line carrying the vaporous reactants to the burner or within the burner itself. This leads to a reduction in the deposition rate of the soot preform that is subsequently consolidated to a blank from which an optical fiber is drawn. Furthermore, particulates of the high molecular weight, high boiling impurities may be deposited on the optical fiber blank, resulting in "defect" or "clustered defect" imperfections that adversely affect the quality of the subsequently drawn fiber and can require scrapping of an entire blank.
Defects are small (i.e. 0.1 to 4.0 mm in diameter) bubbles in a glass body. They can be formed in fused silica by an impurity, such as uncombusted gelled polyalkylsiloxane. A very small particle of siloxane gel can be the initiation site for a defect. The siloxane decomposes at high temperature after being deposited on the glass body, giving off gases which cause the formation of the defect.
Thermophoresis is the process by which soot is attracted to the preform. In fact, it produces the driving force which moves the particles towards the cooler preform. The hot gases from the burner pass around the preform during laydown; the soot particles do not have sufficient momentum by combustion alone to strike the preform. Thermophoresis moves particles in a temperature gradient from hot regions to cooler regions. The burnt gases from a burner are hotter than the preform. As these gases pass around the preform, a temperature gradient is produced. Hot gas molecules have higher velocity than cold gas molecules. When hot gas molecules strike a particle, they transmit more momentum to the particle than a cold gas molecule does. Thus, particles are driven towards the colder gas molecules and, in turn, toward the preform.
Clustered defects are larger glass defects found in optical fiber preforms. They are made up of a series of defects in the form of a line or a funnel- or flower-shaped cluster. A large particle of gel can be the initiation site for a clustered defect. After the gel particle has struck the porous preform, it causes a raised area to stand out from the preform surface. Because the clustered defect is a raised site, more heat transfer passes to this site. Because of this increased heat transfer, more thermophoresis occurs at this site, causing the imperfection to grow and leave behind a string of defects. As a result of the clustered defect, the affected portion of the optical fiber preform cannot be consolidated normally, and the consequent irregularity in the blank yields defective optical fiber.
Thus, there is a need for a purified polyalkylsiloxane composition having a very low concentration of high boiling impurities to serve as a feedstock for the production of high purity fused silica glass and articles formed therefrom, including optical waveguide fibers. The present invention is directed to fulfilling this need.

Method for purifying polyalkylsiloxanes and the resulting products


A lifting apparatus to facilitate lifting and maneuvering of a scaffold or the like by a forklift is provided. The lifting apparatus includes two identical portions, each portion including two end structure portions and a backbone portion. The end structure portions removably secure the lifting apparatus to the scaffold. The backbone portion is adapted to accommodate the width of the working platform of a scaffold, to link the end structure portions together, and to provide locations for a forklift to attach to the lifting apparatus. The lifting apparatus is adapted to allow the forklift to align perpendicular or parallel to the length of the scaffold. Furthermore, the lifting apparatus aligns the lifting structure of the scaffold with the center of mass of the scaffold.

Large hydraulic scaffolds are commonly used in the construction industry to allow workers to be properly positioned at the worksite to accomplish their task. Generally, the workers are constructing or working on a wall of a building or structure. As the work progresses, the hydraulic scaffold may be raised or lowered as required to re-position the workers and to acquire and off load additional materials. These hydraulic scaffolds provide a significant advantage over rigid scaffold, which is typically constructed in a fixed manner. Once constructed, the rigid scaffold requires that the workers climb up and down the skeleton of the scaffold to reach the work platforms. The skeleton of the platform must also be manually constructed and destructed to relocate the scaffold as the work progresses at the construction site.
A typical base scaffold unit includes a working platform section, hydraulic motors, lifting towers, etc. The length of the working platform of the hydraulic scaffold assembly may be expanded quite extensively by adding additional scaffold units to the base scaffold unit. An industrial-strength extendible-boom forklift is typically used to move the hydraulic scaffold and assemble the sections to form the scaffold assembly. To facilitate the lifting of these various scaffold sections, each scaffold unit includes pre-installed forklift tang receptacles on the edge and under the scaffold platform. These receptacles are positioned about the center of the length of the scaffold unit to accommodate the forklift tangs to facilitate the lifting and movement of that single unit such that the weight of the scaffold is roughly balanced.
When two sections of scaffold are coupled together to extend the working length of the platform, it is still desirable to lift the assembly from the center to balance the weight. However, the positioning of the tang receptacles on one section do not align with those on the other section to accommodate both forklift tangs when attempting to balance the load when lifting the assembly. However, the forklift must be positioned such that the load is balanced on each side of the forklift. Unfortunately, the spacing between the receptacles on each end of the connected sections is wider than the spacing between the forklift tangs. While one forklift tang may be accommodated in a receptacle of one platform portion, the receptacle of the added platform portion is not positioned to allow the other forklift tang to be accommodated therein. As a result, at least one of the tangs of the forklift is not accommodated in a receptacle and the scaffold simply rests on this tang. In this limited controlled configuration, damage to the hydraulic scaffold assembly, the support structures of the scaffold and the forklift may result.
Additionally, even when a single scaffold unit is lifted by a forklift with both tangs properly in the receptacles, the depth of the working platform for a typical hydraulic scaffold is such that a significant torque arm is presented to the forklift. As will be discussed more fully below in relation to FIG. 6, this torque arm is created because the forklift is required to lift the hydraulic scaffold from the side of the working platform. Indeed, this lifting position is furthest from the center of mass of the scaffold when the base scaffold unit is lifted. This is because the hydraulic motors, towers, and lifting mechanism must be positioned adjacent to the building so that the weight of the workers and bricks do not present a significant torque on the lifting structure of the scaffold itself during use. Furthermore, the offset center of mass of the scaffold is a safety feature, because this configuration tends to cause the scaffold to tip towards the building, rather than away from the building. However, the amount of weight and torque presented to the forklift that is lifting the scaffold from the side opposite the center of mass can be significant. The significant torque presented to the forklift by the weight of the scaffold has been known to create stress and fatigue cracking of integral lifting components of the forklift.
Indeed, this torque loading on the forklift resulting from the positioning of the forklift receptacles of these hydraulic scaffolds is such that it is difficult if not impossible to lift a hydraulic scaffold assembly that includes multiple scaffold units. As a result, the scaffold assembly must be taken apart to allow the scaffold to be moved around or to the work site. This assembly and disassembly process wastes significant amounts of time and money.
Not only is the need to assemble and disassembly the scaffold wasteful of time and money, but it is difficult as well. That is, adding and removing additional platform units to a hydraulic scaffold assembly is not aided by the positioning of the tang receptacles. This is because the positioning of the receptacles requires the forklift to be positioned transverse to the direction of movement necessary to add the additional platform unit to the assembly. Specifically, the receptacles require that the forklift be positioned perpendicular to the length of the scaffold unit. However, the scaffold unit must be moved in a direction along its length to be brought into conjunction with another unit. Since a typical forklift cannot move sidewise (perpendicular to the direction that it is facing), it is of little use in constructing the scaffold assembly.
However, since these units are quite heavy, it is most desirable to use the forklift to maneuver these units to aid in their assembly. Currently, in an attempt to use the lifting power of the forklift when assembly multiple units, chains or straps are used. Specifically, the forklift is positioned in-line with the length of the scaffold unit to be moved and chains or straps coupled to the scaffold unit are picked up by the tangs of the forklift. The forklift is then driven forward to bring the scaffold unit into conjunction with another unit. Unfortunately, since neither chains nor straps provide a rigid connection with the platform, the scaffold unit may swing and sway. This severely limits the forklift operator's control over movement and positioning of the additional scaffold unit. This lack of control over the scaffold unit requires additional workers to steady the scaffold unit while it is being lifted and moved into position and to assist in the assembly of the scaffold. Also, if the chains and straps are improperly attached to the platform, structural members of the platform may become damaged. Furthermore, the size of chains required to lift the scaffold are themselves heavy, inconvenient and expensive.
Therefore, there exists a need in the art for a mechanism that facilitates the lifting, movement, assembly, and disassembly of scaffold units that overcomes the above described and other problems existing in the art.

Lifting apparatus for scaffold and method


A method for preventing the copying of useable video content is disclosed. The method includes identifying the video signal content of a video signal that is suitable to be extracted, extracting video content from the video signal to transmit to a receiver, and replacing the extracted video content with marred video content in the video signal. The method further includes placing the extracted video content in a user data channel of a program stream for transmission to a receiver. In addition, the method includes transmitting portions of the video signal that contains the marred video content in a first channel of the program stream, and transmitting the extracted video content in a second channel of the program stream to the receiver. The signals transmitted in the program stream are synchronized for presentation in the display of the receiver. Only the program stream components that contain the marred video content may be recorded by a VCR or DVD recorder and the marred video is unsuitable for piracy or rebroadcast.

Feature presentations such as sporting events, live concerts, and broadcast premieres etc., are among the most highly valued assets of television program content providers. Their exclusive control of the availability of this material significantly increases its value. Consequently, program content providers are able to charge a premium for access to such programs. The unauthorized copying of these programs diminishes their value.
Currently, content providers are limited in their capacity to prevent unauthorized copying of program content. One measure employed by content providers is watermarking. Watermarking entails placing a logo on the displayed video image. In many cases the logo is placed in the corner of the displayed video image. However, this measure has proven to be practically useless as a meaningful deterrent to unauthorized copying of the program.
Another technique that has been employed is the use of copy control information (CCI). A feature of this scheme is the transfer of data from transmitter to receiver where the transmitter side system determines the copy restriction level of the content that is being transmitted. In addition, the qualifications of the receiver side system to receive the content can be verified. If complete authentication is established between the receiver-side system and the transmitter-side system, the content is encrypted and transmitted from transmitter to receiver. Once the content has been received, the CCI information may be modified to indicate that copying is prohibited so that unauthorized copying may be prevented.
A drawback of the use of CCI information is its reliance on the receiver side system to perform operations that prevent receiver-side devices from making unauthorized copies of the transmitted content. For example, upon receiving the transmitted content, the receiver side system may be employed to rewrite the CCI information to include data that either facilitates: (1) free copying, (2) the permission of one time copying, or (3) the prohibition of copying altogether. However, because of the relative ease with which the data that facilitates the free copying of the transmitted content may be manipulated, through such manipulation, unauthorized copying may be facilitated.
Other measures employed include the inclusion of stern warnings that outline the legal penalties that may be incurred for making copies of video content or re-broadcasting it without permission. However, such measures do not eliminate the users capacity to make perfectly clean copies of transmitted video content using VCR or DVD recorders. Consequently this system, along with the other systems currently available, do not prevent the unauthorized copying of transmitted video content, that is currently widespread, from continuing unabated.

Method and system for preventing the unauthorized copying of video content