A multistation press has a three-axis transfer provided with transport rails onto which carrier rails are placed. The carrier rails carry grippers for the workpieces. During the tool change, the carrier rails are deposited on corresponding receiving devices of the sliding table. The transport rail is at first moved to deposit a first carrier rail connected therewith on the receiving device. Then the transport rail is separated from the carrier rail and is moved to bring a second carrier rail still connected therewith to the receiving device. The receiving device receives the second carrier rail in the immediate vicinity of the first carrier rail, whereby two carrier rails overlap and are spaced closely side-by-side. The receiving device is then laterally swivelled away. The carrier rails are deposited on the receiving device without the aid of driving devices operating between the transport rail and the carrier rail.

The present invention relates to a multistation press having several press stations arranged behind one another corresponding to a machining sequence.
Multistation presses are frequently constructed as an individual machine or as a system of presses which are directly linked with one another. This is particularly so if they operate in a given cycle in a mutually coordinated manner and are linked with one another by a transfer system which transports workpieces from one press station to the next. In this known type of press, the press stations are provided with tools which are set up for the respective workpiece type to be machined. Gripper devices are also provided on the transfer system for the special workpiece to be machined and to be transported.
If multistation presses are constructed for the machining of a special workpiece or are converted from the machining of one workpiece to the machining of another workpiece, the workpiece-specific parts of the press stations and of the transfer system must be exchanged. This should take place as fast and automatically as possible.
DE 38 43 975 C1 describes a transport device for larger workpieces for a transfer press. The transfer press has several press stations which are arranged along a transport direction, are spaced away from one another and in which bottom dies or bottom tools provided for receiving the workpieces are exchangeably arranged on sliding tables. Above the sliding tables, slides are provided which can be moved vertically up and down and which are driven synchronously. Each slide is equipped with a top tool and, together with the bottom tool arranged on the sliding table, defines a press station.
For the known workpiece transport, a cross-traverse transfer device is arranged between the press stations and has two mutually parallel transport rails. The transport rails are guided on both sides of the press stations along the entire length of the transfer press and are connected with one another by cross-traverses. Coupling devices detachably couple the cross-traverses are detachably connected with the transport rails. Between the press stations, so-called rig pins are arranged which are each connected in pairs with a sliding table and are used for receiving the cross-traverses to be exchanged. For the conversion, i.e., for exchanging the workpiece-specific parts of the press, the cross-traverses are deposited on the rig pins and are moved by the sliding tables laterally out of the press.
During the construction of this press, care must be taken that also the rig pins, which are arranged between the sliding tables and are each connected with a sliding table, can be moved laterally out of the press. For this reason, neither sliding tables nor rig pins connected with them can be arranged in the column area.
DE-PS 36 07 323 describes a press working line with individual presses in which the workpiece transport is carried out by gripper rails. To permit an automatic converting operation, the presses are equipped with sliding tables which can be moved in and out through the press columns of the press transversely to the transport direction of the parts. The respective sliding table permit the exchange of the tools which are used for machining the workpieces. The gripper rails provided for the transfer have part-related gripper rail parts which are each set up for the transport of the special part to be transported.
An exchange of these gripper rail parts is permitted by dividing each of the gripper rail parts into three parts which are detachably connected with the gripper rail. The gripper rail parts are equipped with the grippers which must be engaged with the respective workpiece while the continuous sections of the gripper rails are used only as supports for the gripper rail parts. The gripper rail parts are formed by one center part respectively as well as two exterior adjoining parts. Relative to the respective center part, the exterior parts are telescopically displaceable and are driven by piston-cylinder units.
For exchanging the gripper rail parts, the exterior parts are adjusted by the piston-cylinder units in the direction of the center part, after which the gripper rail parts forming a unit are deposited on a corresponding receiving device of the sliding table and are moved out of the press. The considerable weight of the gripper rails and of the piston-cylinder units driving them disadvantageously increases the weight of the gripper rails.
U.S. Pat. No. 5,248,288 describes a transfer press system which has several linked successive press stations by a cross-traverse transfer device. The cross-traverse transfer device has two parallel transport rails which are driven synchronously. Between the transport rails, cross-traverses are suspended transversely to the transport direction and are detachably connected with the transport rails by coupling devices. In each press station, a sliding table is provided by which the deforming tools can be moved laterally out of the press area. Each sliding table is equipped with a receiving device for cross-traverses detached from the transport rods which is arranged in a space defined by the adjacent sliding table. This receiving device contains two telescopic cylinders which, by way of a lever parallelogram, can be swivelled in parallel to the sliding table and can be height adjusted.
For the tool change, the receiving device takes the cross-traverses off the transport rails and folds the cross-traverses against the workpieces situated on the sliding table in order to achieve a compact arrangement of the tools to be exchanged. This manner of exchanging the gripper devices and the tools requires a transfer system with cross-traverses which requires spaces between the sliding tables.
DE 43 09 643 A12 describes a transfer device for the workpiece transfer which is constructed as a three-axis transfer. The transfer device is provided on a press with several press stations and has two transport rails extending at a distance parallel along the entire press length. These transport rails are synchronously moved in and against the transport direction, and are lifted and lowered as required by way of corresponding lifting devices. In addition, the transport rails can be moved toward and away from one another. The transport rails support carrier rails equipped with workpiece gripping devices. Depositing supports for receiving carrier rails are provided on each sliding table. In order to separate the carrier rails from the transport rails and place them on the depositing devices, particularly carrier rails situated in the column area are moved by the transport rails out of the column area and into the corresponding depositing position at the sliding tables and are deposited in a mutually aligned manner. In this position, the carrier rails with the sliding tables and the tools deposited thereon can be moved laterally out of the press.
Particularly in the case of presses with several columns which stand relatively close to one another, the passages required for the lateral moving out of the sliding tables are relatively limited with respect to their dimensions, and this can present problems.
It is an object of the present invention to provide a multistation press with a transfer device in which tools used for machining the workpieces, as well as gripper devices used for the transport of the workpieces and provided on the transfer device, can be automatically and simply exchanged without the requirement of additional space for moving the transport rails or for the lateral moving out of the sliding tables.
It is another object of the present invention to provide a process for changing the gripper devices during a tool change which meets the above-mentioned requirements.
These objects have been achieved in accordance with the present invention by providing a multistation press having a plurality of press stations arranged behind one another corresponding to a machining sequence; sliding tables associated with respective ones of the press stations; a transfer device for transporting workpieces between the press stations in a transport direction, and having at least two transport rails; a driving device for driving the transport rails to carry out a transfer movement; carrier devices detachably connected in a mutually spaced manner with the transport rails and provided with gripper devices; and at least one receiving device provided on the sliding table and arranged for connecting with the carrier devices, and for holding at least two separate carrier devices in spaced relationship to one another, wherein the carrier devices have a smaller distance from one another with respect to the distance on the transport rails.
In addition, the objects are achieved by a process for changing tools and gripper devices in press systems provided with sliding tables and with a workpiece transfer system, in which the workpiece transfer system has transport rails detachably connected with mutually separate carrier devices carrying gripper devices, comprising the steps of bringing a receiving device provided on the sliding table to the sliding table in a movement directed laterally to a transport direction defined by the workpiece flow; bringing the carrier device to a receiving point of the receiving device by a movement of the transport rail to be coupled therewith; detaching the transport rail from the carrier device which is now carried by the receiving device; bringing another carrier device to another receiving point of the receiving device by another movement of the transport rail to be coupled therewith, whereby the receiving points are adjacent each other; detaching the transport rail from the another carrier device which is now carried by the receiving device; moving the receiving device away by the sliding table; and moving the sliding table, which carries the tool and the carrier device, laterally out of a working range of the press system.
The multistation press of the present invention which may be an individual machine or a sequence of several presses linked with one another by the transfer device, is provided with sliding tables which can be moved laterally out of the press and permit a quick tool change. The transfer device has two mutually parallel transport rails which support mutually spaced carrier devices which, in turn, are provided with gripper devices for the workpieces. The carrier devices can be detached from the transport rails, with receiving devices for receiving the carrier rails are arranged on the sliding tables.
The carrier devices are each arranged on the transport rails in a mutually spaced manner, and the receiving devices of the sliding tables are constructed such that the carrier devices can be deposited close to one another, in which case they are not aligned with one another. Two carrier devices which are mutually adjacent on the transport rail carry out a longitudinal stroke during the transfer movement which longitudinal stroke corresponds to their respective own length plus the distance to the respective next adjacent carrier device.
Both carrier devices can be housed on the sliding table in an area whose longitudinal course measured in the transport direction does not exceed the stroke width and is preferably maximally as long as a single carrier device. This can be achieved particularly by an overlapping arrangement of the carrier devices in that these are, for example, stacked above one another. Such a housing of the carrier devices permits the receiving of additional carrier devices which will be required particularly if intermediate depositing devices are arranged between the sliding tables Each transport rail will then support two carrier devices per sliding table.
As a result of the receiving of the carrier devices on the sliding tables which saves space in the longitudinal direction, carrier devices situated in the column area are movable by a longitudinal stroke movement of the transport rails out of the column area to be deposited on corresponding holding devices of the sliding table in a mutually overlapping manner. A sliding table can receive on each side, for example, two carrier devices arranged above one another which do not project beyond the sliding table. It can, therefore, be moved without any problems laterally out of the press area even if the passage provided for this purpose is restricted by adjacent press columns.
Furthermore, no devices are required for providing the carrier devices with a longitudinal movement with respect to the transport rails. Thereby, the mass of the carrier devices and transport rails and thus the occurring accelerating and braking forces remain within limits. This is a particular advantage in view of the transport rail driving device.
A particularly space-saving arrangement of the carrier devices on the sliding tables is obtained if the carrier devices are parallel to one another, either next to one another or above one another. If, in this case, the carrier devices each have a low height, the vertical adjustability of the transport rail, which exists anyhow, will be sufficient for depositing the carrier device on the receiving devices. This preferably takes place without providing driving devices on the carrier devices. That is, the carrier devices have a purely passive construction which keeps their weight comparatively low.
For fastening the carrier rail on the transport rail, a locking device is preferably arranged to act between them and has the purpose of coupling the gripper devices during the normal operation of the transfer device, i.e., during the workpiece transfer, stationarily to the transport rails. As soon as the carrier device is received by the receiving device and is form-lockingly connected therewith, the locking device will change into the release position. As a result of a suitable longitudinal movement, the transport rail can detach and separate from the carrier device.
The receiving device, which can, for example, also be rigid, is preferably swivellably disposed at the sliding table. Thereby, after the transfer of the carrier devices has taken place, the receiving device can be laterally swivelled away so that the gripper devices can be moved out of the tool range and the carrier devices can be moved out of the moving range of the transport rail.
The transfer unit which is formed by the transport rails of the driving unit and the gripper devices is preferably constructed as a three-axis transfer. The transport rails are arranged parallel to one another as well as parallel to the transport direction and can be moved in, the transport direction; i.e., horizontally, vertically as well as toward and away from one another. In such a three-axis transfer, the transferring of the carrier devices held by the transport rails to the corresponding receiving devices on the sliding tables can be carried out in a particularly simple manner using the three-axis transfer for the fetching and the suspending of the carrier devices in the receiving devices without the aid of additional driving units.
A transport rail allows the first one of the carrier devices received by the holding device to be first inserted into the holding device by a lateral depositing movement. Thereafter, the transport rail is separated from the carrier device preferably by a combined advancing/lowering movement. Then the transport rail brings the additional carrier device to be connected with the holding device and deposits it thereon. The carrier devices can be held close to one another and therefore held in a very space-saving manner on the sliding table.


A data communication receiver (100) includes a first antenna feed (106) coupled to a first receiver element (110) for demodulating (502) a radio signal containing data bits and for deriving a first phase-locked loop error signal. The data communication receiver (100) also includes a second antenna feed (108) coupled to a second receiver element (112) for demodulating (502) the radio signal and for deriving a second phase-locked loop error signal. A received signal strength indicator (134, 144) measures signal strength of the radio signal from the first antenna feed (106) during reception of a data bit, and concurrently measures signal strength from the second antenna feed (108). A processor (146) then defines (506, 508, 512) the data bit as received from the antenna feed (106, 108) having the greater signal strength to be the optimum data bit.

Diversity reception radio receivers are well known in the art. Such receivers have been used to substantially improve radio reception in a changing multipath environment. Diversity receivers are particularly desirable in mobile and portable applications, in which a receiver may be moved into an isolated weak signal area caused by self-cancellation of multipath signals.
One conventional approach to a diversity receiver has comprised a dual antenna space-diversity system, the dual antennas coupled to a switch for selectively coupling one of the dual antennas to a single receiver. During operation the receiver is switched to an alternate antenna in response to a signal received from a currently selected antenna deteriorating below a predetermined switching threshold. This approach has a drawback in that the approach does not always select the antenna having the stronger signal. For example, a currently selected antenna having a signal marginally above the predetermined switching threshold would remain selected, even though a signal from a non-selected antenna is much stronger.
Another conventional approach to the diversity receiver has comprised a dual space-diversity antenna system separately coupled to dual receiver elements for amplifying and demodulating a radio signal received by the dual antennas. Such receivers have typically utilized an electronic switch to select the "best" output signal from one of the dual receiver elements based upon a measurable selection criterion, such as signal-to-noise ratio. Unfortunately, some conventional output signal selection techniques have been slow to respond, possibly causing loss of received information. Also, while the dual receiver approach to diversity reception has provided performance superior to the single receiver approach, it has typically been a power-hungry approach. This is because the dual receiver approach obviously has required double the amount of receiver circuitry and thus double the power of the single receiver approach. Power requirements are an especially important design consideration in battery powered portable receivers, such as selective call receivers, thereby limiting the widespread use of the conventional dual-receiver diversity approach for such applications.
Thus, what is needed is a way of building a diversity receiver that provides the superior performance of the dual receiver approach but does not require double the amount of power compared to the single receiver approach. A diversity receiver is needed that can switch to a better signal source quickly enough to avoid missing any received information.

Method and apparatus for dual-channel diversity reception of a radio signal


In a method of monitoring the operation of a plain bearing, a lubricant passage (15) of a bearing segment, this lubricating passage (15) being provided for jacking oil for example, is used during hydrodynamic operation of the plain bearing for extracting samples for a temperature measurement. For producing the measuring operation, a switch-over device (19) clears a flow path from the lubricant passage (15) into an outflow passage (23) in such a way that lubricant from the lubricating film (13) flows through the lubricant passage, the temperarature of this lubricant being determined by a temperature sensor (16, 18).

In a hydrostatic or hydrodynamic plain bearing, in which the actual support is carried out by a formed thin lubricating film consisting of a fluid (e.g. of an oil), a measurement of the temperature of the lubricant in the lubricating film or a temperature measurement in the adjacent sliding surfaces provides information about the state of the bearing and is therefore especially suitable for monitoring the operation.
Thus it is known from EP 0 161 644, in a plain bearing for the early detection of damage, to monitor the temperature in the region of the sliding layer in order to be able to take countermeasures in good time in the event of a noticeable increase in temperature. In this case, however, a change in the lubricant temperature is recorded with a considerable time delay and only indirectly. Even if the temperature sensor were to be run directly to the surface or sliding surface, the temperature of the bearing segment at best would be measured. The lubricant or fluid temperature may locally be markedly above this, since 90-97% of the heat generated in the fluid is dissipated by the fluid itself, that is to say past the temperature sensor; only 5% of the heat in terms of the order of magnitude is directed through the bearing segment.
A direct measurement of the lubricant temperature in the lubricating film is not known in the prior art. The problem with the direct measurement is that the film, for example in the case of oil as lubricant, is only 20 μm to about 200 μm thick, so that no probes can be fitted. German Patent 883 984 specifies a bearing design for rolling mills which is supplied with an excess lubricant quantity for cooling, which is larger than the lubricant quantity which is to penetrate into the lubricating gaps. The excess quantity is drawn off from fresh-oil chambers through a return line. German Patent 883 984 proposes to arrange a temperature sensor in this return line in order to determine the temperature of the bearing surface. In this case, however, there is on the one hand the risk of the measurement being distorted by feed lubricant; on the other hand, the proposed measuring method can only be used in special bearings which are operated with excess oil. Furthermore, there are considerable uncertainties when drawing conclusions about the temperature in the bearing gap, since of course the measured medium does not originate explicitly from the bearing gap.

Method and device for monitoring the operation of a plain bearing


An apparatus for the artificial ageing of blocks, in particular concrete blocks, clinker bricks and natural stone blocks, has a base on which the blocks can be placed in such a way that their surfaces to be treated and the adjoining edges are exposed. Essentially freely movable striking bodies are used for treating the surfaces and the adjoining edges of the blocks. A vibrating device sets the blocks and the striking bodies in motion relative to one another in such a way that the striking bodies act on the surfaces and the exposed edges of the blocks. In this case, the striking bodies are movably fastened to a retaining device in such a way that the striking bodies are freely movable within a defined region of the surface of the blocks.

An apparatus of the generic type for ageing has been disclosed by DE 20 2004 020 206.9.
Blocks, for example, surfacing elements, facade elements, sand-lime blocks, concrete blocks, bricks or clinker bricks, natural stone blocks and the like, irrespective of their material condition, are often subjected to a subsequent treatment in order to lose their artificial appearance.
Freshly produced, set concrete blocks, in particular concrete paving blocks, are subjected to such a subsequent treatment especially frequently, in the course of which the surfaces and/or the edges are struck or broken in order to adapt the appearance to natural stone in this way. To this end, a relatively large number of concrete blocks are put into a rotary drum and "rumbled" there; the surfaces and edges of the blocks striking one another and the blocks thus treated leaving the drum in an "aged" state. Such an apparatus has been disclosed by DE-A 29 22 393.
During the treatment of the concrete blocks in a rotary drum, surfaces and edges which, for example when using the aged blocks, are not visible at all in a paving are also treated. To this extent, energy and time are needlessly wasted. Furthermore, it is necessary to put the treated concrete blocks leaving the rotary drum onto a pallet for dispatching in a regular arrangement, the amount of work and time which this involves being disproportionately high.
Sorting installations for sorting the blocks are known from the prior art, these sorting installations accordingly orienting the blocks and arranging them in a pallet form. Such sorting installations involve high procurement and operating costs and also take up a corresponding amount of space.
DE 36 21 276 C2 discloses a method in which concrete blocks are put onto a plate-like base in a single layer in a regular arrangement. The exposed surfaces and the adjoining exposed edges or essentially only the edges of the concrete blocks are then struck irregularly by way of a vibrating knocking or striking device.
Due to this method, a subsequent sorting device can be dispensed with, since the production layer is not changed. Before the treatment by the knocking or striking devices, the blocks are pushed together and oriented on the plate-like base, so that the blocks fit closely against one another and there is no longer any intermediate spaces between them. The striking tools of the striking device are arranged on a movable carriage which guides said striking tools across the surfaces of the blocks, so that the free surfaces of the blocks and those edges of the blocks lying at the top are struck by the striking tools.
A disadvantage with this method, however, is that the blocks aged in this way look artificially treated and not naturally aged. The use of the method of the generic publication does not result in ideal breaking of the edges of the blocks as is obtained by the rumbling of the blocks in a rotary drum.
Disclosed by EP 0 860 258 B2 is an apparatus and a method in which the blocks are arranged in one or two layers, preferably in their production layer, between two elements, preferably plates. In this case, the bottom plate, on which the concrete blocks rest, is in interaction with a vibrating device. The blocks are set in motion by the vibrating device so that they move back and forth between the plates. In the process, the blocks strike one another and also strike the top and the bottom plate as a result of which the edges on the top side and the underside are broken. In addition, the top sides and the undersides of the blocks are struck by the respectively assigned plates. The vertical side edges of the concrete blocks and the side faces are broken or struck by the respectively adjoining concrete blocks.
It has been found in tests that the breaking of the edges is all the poorer, the larger the block to be aged is. This results from the fact that the striking angle becomes all the smaller, the larger the block put between the plates is. The small striking angle results in unfavorable breaking of the edges.
As with the ageing method by way of the rotary drum, there is the disadvantage in this case that surfaces and edges of the blocks are treated which are possibly not visible at all, as a result of which energy and time are needlessly wasted. In addition, the requisite treatment time, in particular in the case of set concrete blocks, is long and the breaking of the edges is not ideal.
The generic publication DE 20 2004 020 206.9 discloses an apparatus for the artificial ageing of blocks in which the blocks (preferably in their production layer) are placed on a base, so that the surfaces to be treated and the adjoining edges of the blocks are exposed. By way of a magnet, freely movable striking bodies (of metal) are then applied to the surface to be treated. The base on which the blocks rest is set in vibration by way of a vibrating device. The blocks and the striking bodies are, therefore, set in motion relative to one another in such a way that the striking bodies act on the surfaces and the exposed edges of the blocks.
The apparatus disclosed by DE 20 2004 020 206.9 enables rapid and effective ageing of the top side of the blocks and the adjoining, exposed edges. The striking bodies randomly hit the surface of the blocks and, therefore, strike the latter irregularly, so that an optical effect is produced which corresponds to that of a naturally aged block.
According to the ageing process, the metallic striking bodies are lifted from the surface of the blocks again by the magnet by the latter being brought close to the blocks. The block layer can be removed and a new block layer can be fed. It is a disadvantage that the magnet to be used involves high costs. A further disadvantage is that downtimes occur due to the striking bodies being put down and picked up again by the magnet and these downtimes lead to longer cycle times.
The object of the present invention is, therefore, to improve the apparatus disclosed by the generic publication for the artificial ageing of blocks, in particular to develop an apparatus and a method which permits especially cost-effective and rapid ageing of blocks.

Process and apparatus for artificially ageing blocks

Baustoffwerke Gebhart & Sohne GmbH & Co. KG


A refillable tape dispenser comprising a housing including a side wall, and a hub having a longitudinal axis defining an axial direction. The hub has inner and outer surfaces, and a first end fixed to the side wall. The hub comprises first and second opposed flexible portions having distal ends remote from the side wall which flexible portions project axially from the side wall. The dispenser also includes a retaining lug at the distal end of each of the flexible portions. The retaining lugs have remote ends spaced axially from the flexible portions. Ribs are present at the distal end of each of the flexible portions. The ribs project radially outward of the flexible portions and have axially extending arcuate bearing surfaces. The dispenser of the present invention is particularly suitable for coupling to a backcard having chevron-shaped openings.

The art is replete with dispensers including a polymeric housing including a hub, a roll of tape including a core journaled on the hub and a length of pressure sensitive adhesive coated tape helically wound around the core, and a paper backcard attached at one end of the hub by which the dispenser can be hung on a display shelf or rack. The backcard is disposed around one end of the hub with the hub disposed within a through opening in the core and a portion of the backcard adjacent one side surface of the roll of tape.
In a known non-reuseable type dispenser, the backcard is held adjacent one side surface of the roll of tape and the roll of tape is prevented from sliding axially off the cylindrical outer surface of the hub by a series of tabs integral with the hub and formed by heat sealing or ultrasonically welding the tabs in a position projecting generally perpendicular to a longitudinal axis of the hub. While the backcard is reliably attached to the dispenser, the heat sealing or ultrasonic processes used to form the tabs are irreversible and thus result in a product which is non-reuseable and non-refillable. Also, the heat sealing process used to form the tabs requires time during the manufacturing process which increases the time needed to manufacture a dispenser.
Non-reuseable dispensers are associated with environmental problems, such as problems related with disposal of spent dispensers. Many hand held tape dispensers are manufactured from polystyrene which has a relatively slow degeneration rate. These types of dispensers are used until the roll of tape is depleted and then disposed.
FIGS. 1 and 2 are illustrations of existing tape dispensers which can be re-used. The dispenser 10 depicted in FIG. 1 is a SCOTCH brand transparent tape dispenser available from 3M Argentina. The dispenser 50 of FIGS. 2 and 2A is a NICHIBAN double sided tape dispenser available from Nichiban of Japan which has many parts that are essentially the same as the parts of the dispenser 10 and which have been identified by the same reference numeral to which has been added the suffix "A". Each dispenser 10, 50 includes a housing 20, 20A including a side wall 21, 21A, and a tubular hub 22, 22A having cylindrical inner 23, 23A and outer 24, 24A surfaces, and a first end 25A (FIG. 2A) fixed to the side wall 21, 21A. The hub 22, 22A comprises a base portion 26A joined to the side wall 21, 21A opposite arcuate guide portions 27, 27A projecting axially from the base portion 26A, and first 28, 28A and second 29, 29A opposed arcuate arm portions having a distal end 30, 30A remote from the base portion 26A. The first 28, 28A and second 29, 29A arm portions project axially from the base portion 26A between the guide portions 27, 27A.
The distal ends 30, 30A of the arm portions 28, 28A, 29, 29A include planar cam surfaces 31, 31A and lips 32, 32A; 33, 33A extending radially outward from the hub adjacent the planar cam surface 31, 31A and each of the arm portions 28, 28A, 29, 29A further have arcuate or sloping edges 34, 35, 36, 37; 34A, 35A, 36A, 37A adjacent their distal ends 30, 30A which are located at the edges of the planar cam surfaces 31, 31A. The dispenser 50 shown in FIG. 2 includes an axially extending rib 51A that is believed to assist the hub 22A in holding the backcard 41A on the dispenser 50.
FIGS. 7 and 7A show typical backcards 40, 40A used with the dispensers 10, 50 of FIGS. 1, 2 and 2A which include a hanging aperture 41, 41A adapted to afford display of the dispenser 10, 50, and through openings 42, 42A, 43, 43A disposed between an outer portion of the dispenser housing 49, 49A and the lips 32, 32A, 33, 33A of the hub 22, 22A. The backcard 40 of FIG. 7 is used in conjunction with the dispenser 10 shown in FIG. 1, and comprises cuts 44 and 45 which extend radially away from the through openings 42, 43. The cuts 44, 45 are adapted to permit flexing of the backcard 40 to afford passage of the cam surfaces 31 and lips 32, 33 of the hub 22 through the openings 42, 43 from one side of the backcard 40 to the other during joining of the backcard to the dispenser.
The backcard 40A illustrated in FIG. 7A is used in conjunction with the dispenser 50 shown in FIG. 2. Unlike the guide portions 27 of the dispenser 10, the guide portions 27A of the dispenser 50 extend axially beyond the outer portion 49A of the dispenser housing and fit into large arcuate holes 52A in the backcard 40A (FIG. 2A). This feature is believed to assist in retaining the backcard upon the hub 22A.
During the manufacturing and assembly processes, the dispensers 10, 50 described in FIGS. 1, 2 and 2A, encounter problems when they are joined to the backcards 40, 40A. To join the backcards 40, 40A to the dispensers 10, 50, the cam surfaces 31, 31A and lips 32, 32A, 33, 33A of the hubs 22, 22A must penetrate the openings 42, 42A, 43, 43A of the backcards 40, 40A. The planar cam surfaces 31, 31A and the distal ends 30, 30A of the arm portions present blunt surfaces which are not readily adapted to penetrate the through openings 42, 42A, 43, 43A of the backcards 40, 40A. A failure to join the backcard to the dispenser may result in undesirable consequences such as an increase in the number of rejected dispensers on an assembly line. Such a result may also cause an accumulation or pile-up of dispensers on an assembly line of a high speed assembler which tends to cause assembler failure.
The dispensers disclosed in FIGS. 1, 2 and 2A also encounter problems with retaining the backcards 40, 40A between the lips 32, 32A, 33, 33A and the outer portion 49, 49A of the dispenser housing 20, 20A. The hand held dispensers 10, 50 are subject to a variety of loads such as torque, vibration and shock loads, which can cause the backcards 40, 40A to separate from the hubs 22, 22A. This is an undesirable result for the user as the user must manually replace the backcards in order to hang the dispenser on a commercial display. One solution to this problem has been to place a length of adhesive coated tape across the backcard 40, 40A and the camming surface 31, 31A. This solution, however, is expensive and requires at least one additional step during the manufacturing process.
Also, backcards which utilize through openings with "square" edges or edges formed by the intersection of two straight members tend to tear at the intersection of the two straight member, particularly when the dispenser and backcard are dropped. Stress is believed to be concentrated at the intersection of the two straight members which tends to cause the backcard to tear at the intersection. Such tearing of the backcard tends to lead to backcard rotation and backcard separation from the dispenser. Excessive backcard rotation adversely affects the product's presentation to the consumer, and backcard separation requires extra effort by the user as the backcard must again be attached to the dispenser before the dispenser may be displayed on a commercial display rack.

Minnesota Mining and Manufacturing Company


A reticle pod, comprising an upper cover having a first accommodating space and a lower cover having a second accommodating space, a third accommodating space being formed after the upper cover and the lower cover close together, wherein the characteristic of the reticle pad is in that: the reticle pod includes a plurality of supporting pieces respectively and suspendingly disposed at each corner of the inner surfaces of the upper cover and of the lower cover, and two ends of each of the plurality of supporting pieces are respectively connected to two neighboring sides of corner of the inner surface to form a closed sheet body and a gap is formed at the bend of the closed sheet body.

1. Field of the Invention
The present invention is related to a reticle pod, and more particularly, to a reticle pod with a plurality of supporting pieces respectively and suspendingly disposed at each corner of the inner surface of the upper cover and the lower cover for ensuring the stability of the photomask stored in the reticle pod and preventing from unnecessary collisions that will lead to displacement or damage of the photomask stored in the reticle pod.
2. Description of the Prior Art
In the rapidly developing semiconductor technology, optical lithography plays an important role and wherever pattern definition is conducted, optical lithography is requisite. In the application of optical lithography relating to semiconductors, a designed circuit pattern is used to produce a light-transparent photomask with a particular shape. With the principle of exposure as basis, after a light source passes through the photomask to project on a silicon wafer, the circuit pattern formed on the photomask can be exposed onto the silicon wafer. Since any dust (such as particles, powders or organic matters) can cause negative impact on the quality of such projected pattern, the photomask used to produce the pattern is required to be kept with absolute cleanness, and therefore in ordinary wafer process, clean room environment is provided to prevent from contamination of particles in the air. However, the status of absolute cleanliness still cannot be achieved in the clean room currently in use. At present, anti-contamination reticle pod is used in the semiconductor process for storing and transporting the photomask to ensure the cleanliness of the photomask.
However, when the reticle pod is used to store and transport the photomask, a plurality of supporting pieces need to be disposed in the reticle pod for supporting and propping up the photomask. When the photomask is placed in the reticle pod for storage, the supporting pieces are in direct contact with the photomask and therefore friction between the supporting pieces and the photomask occur more easily and will then generate static electricity that leads to damage of the photomask; when the photomask is placed in the reticle pod for being transported, the vibration generated in the transporting process will cause damage or crack of the photomask more easily. How to provide the supporting pieces with both the merit of resistance to damage from static electricity and the merit of anti-vibration thus becomes a critical subject.


A hammerhead used for magnetically holding different sizes and lengths of nails. Also, the hammerhead can be used for holding tacks, brads and other types of fasteners. The hammerhead is used to start the initial driving of a nail into a nail receiving surface and avoids the holding of the nail with one hand and possibly hitting the hand with the hammerhead. The hammerhead is characterized by having a head member with an outwardly extending annular shaped nose. The nose includes a rear portion integral to and extending outwardly from the head member, a front portion with a nail striking face, a top portion and a bottom portion. The length of the top portion of the nose includes a "V" shaped groove for receiving a portion of the nail therein. A magnet hole, in the top portion of the nose, is disposed next to the nail striking face. The magnet hole is used for receiving a magnet with a non-magnetic sleeve therearound. Extending downwardly from the magnet hole is a knock-out hole which is used for removing the magnet when the magnet is damaged or it loses it's magnetic flux. The top of the magnet is disposed along the length of the "V" shaped groove for holding the nail received in the groove. The top portion also includes a nail head slot at one end of the "V" shaped groove for receiving different size nail heads.

(a) Field of the Invention
This invention relates to hand held hammers and more particularly, but not by way of limitation, to an improved hammerhead for holding various types of nails and fasteners thereon.
(b) Discussion of Prior Art
Heretofore there have been a variety of different types of hammers using magnets and nail retaining clips for holding a nail when starting the nail into a nail receiving surface.
In U.S. Pat. No. 2,597,876 to Kurkjian and U.S. Pat. No. 4,465,115 to Palomera, hammers are shown with a magnet mounted in the hammerhead for holding a nail in place during the initial driving of the nail into a nail receiving surface. In the Palomera patent, the hammerhead is shown with a magnet held therein using a threaded screw. A longitudinal recess is formed in the top of the hammerhead for receiving a nail with the magnet holding the nail in the recess. The hammerhead described in the Palomera patent does not provide for handling nails of different sizes and lengths. Also, the Palomera patent does describe means for increasing the life of a magnet when mounted on the hammerhead and for providing increased holding power when the nail is engaged by the magnet on top of the hammerhead.
In U.S. Pat. No. 115,008 to Young, U.S. Pat. No. 759,556 to Scholtes, U.S. Pat. No. 1,258,058 to Starrett, U.S. Pat. No. 1,443,864 to Blustein et al., U.S. Pat. No. 1,922,890 to Gevert and U.S. Pat. No. 745,973 to Starrett various types of nail retaining clips are disclosed and mounted on various locations on the hammerhead for starting a nail.
None of the above mentioned patents provide for a magnet next to a nail striking face of a hammerhead for holding different size nails and fasteners for driving the nail or fastener initially into a surface. Also, none of the above mentioned patents and prior art hammers incorporate the unique combination of structure and function of the subject improved hammerhead with magnet nail holder as described herein.


Embodiments of the present invention can provide systems, methods and/or computer program products that can obtain an effective pattern density of a layer of an integrated circuit from layout data that defines the layout. A grid of pattern cells is defined for the layout data. A respective pattern density is determined for a respective the pattern cell in the grid. An effective pattern density is calculated for a first pattern cell in the grid. The effective pattern density for the first pattern cell is a function of the pattern density of at least second pattern cell in the grid that is remote from (i.e. nonadjacent) the first pattern cell, and a distance of the at least a second pattern cell from the first pattern cell. Adjacent cells also may be included, and preferably are included, in the effective pattern density.

This invention relates to systems, methods and computer program products for designing, testing and fabricating integrated circuits, and more particularly to systems, methods and computer program products for determining a density of a pattern in an integrated circuit and for simulating a chemical-mechanical polishing process using the density that was determined.
Present-day Ultra-Large Scale Integration (ULSI) integrated circuits may include hundreds, thousands or millions of interconnected active and passive electronic devices in an integrated circuit chip. The large capital investment to fabricate and test these ULSI circuits prior to sale, and the difficulty, expense and/or loss of goodwill associated with reworking and replacing integrated circuits that fail to operate as planned, have increased the need to accurately simulate the design and fabrication of integrated circuits prior to their fabrication.
In fabricating integrated circuit devices, a plurality of patterned layers, such as wiring layers, generally are formed on a wafer. The patterned layer may cause a relative height difference, often referred to as a step difference, between the patterned and non-patterned areas of the layer. This step difference may increase with the number of layers that are formed, the fineness of the pattern and/or the increase in the level of integration. As is well known to those having skill in the art, an increased step difference can cause failure in many individual integrated circuit fabrication steps, and may also degrade the operating characteristics of the integrated circuit. Accordingly, it is known to provide planarization technology to reduce and preferably minimize the step differences that occur during fabrication of an integrated circuit. Chemical-mechanical polishing (CMP) is a widely used planarization technology.
CMP may be carried out using an apparatus such as that shown in FIG. 1 to planarize integrated circuits as shown in FIGS. 2A and 2B. Referring to FIG. 1, a wafer containing integrated circuits to be planarized is mounted on a wafer carrier 150. As shown in FIG. 2A, the wafer may include an integrated circuit substrate 210 on which a patterned layer 220, such as a metal wiring layer is formed. A planarization layer 230 is formed on the patterned layer 220. In order to perform the CMP process, the wafer carrier 150 is rotated about an axis 160, while a platen 120 on which a polishing pad 110 is mounted, also is rotated about an axis 130. A polishing slurry 170 is disposed on the polishing pad 110, so that the wafer 140 is exposed to a chemical polishing process, in addition to the mechanical polishing due to the friction between the polishing pad 110 and the wafer 140. By performing CMP for a predetermined period of time, the thickness of the planarization layer 230 of FIG. 2A may be reduced, resulting in a polished planarization layer 235, as shown in FIG. 2B, that is generally more planar than the initial planarization layer 230 of FIG. 2A.
Unfortunately, the results of a CMP process may vary depending on several parameters including polishing time, velocity of the platen 120, velocity of the wafer carrier 150, downward polishing pressure of the wafer 140 on the polishing pad 110, and/or the elastic modulus of the polishing pad 110. Accordingly, in certain cases, the CMP may cause a dishing phenomenon (portion A of FIG. 2B) to occur where a region of the planarization layer 235 without a pattern is depressed, or may cause a thinning phenomenon (portion B of FIG. 2B) to occur where fine patterns are polished by the CMP. Accordingly, it is desirable to improve and preferably optimize the above-parameters, to reduce and preferably minimize dishing and/or thinning. Unfortunately, the optimization of these parameters may be a difficult and time consuming task, which may require numerous test runs of the CMP process.
Thus, in order to reduce the time and/or labor involved in determining the parameters through multiple CMP test trials, analytical modeling or simulation using computers has been devised. However, such analytical modeling or simulation should provide accurate prediction within a reasonable time.
U.S. Pat. No. 5,552,996 to Hoffman et al. describes a method and system that can facilitate the control of an IC chip fabrication level of an IC chip fabrication process based upon the design pattern of the IC chip being fabricated. A grid having multiple sections is imposed over the design pattern of a fabrication level of the IC chip. Then, pattern density values are automatically established for the design pattern contained in each section of the grid. The IC chip fabrication level is then controlled based upon the pattern density values. For example, the established pattern density values facilitate the automatic determination of a CMP process stop parameter, or the automatic compensation for etch rate variations caused by pattern density differences across the design pattern of the IC chip.
Moreover, a publication by Takahashi et al. entitled Modeling of Chemical Mechanical Polishing Process for Three-Dimensional Simulation, 1997 Symposium on VLSI Technology, June 1997, pp. 25-26, describes a new model of CMP planarization. Machine time of actual calculation can be estimated less than {fraction (1/100)} of Finite Element Method and the simulation is in excellent agreement with experimental results. This model provides a physical image of planarization for three-dimensional surface profile during CMP. Furthermore, an optimized LSI chip layout or an appropriate processing condition can be estimated. In particular, this method can incorporate the data from adjacent meshes that surround a specified mesh.
Notwithstanding the above discussion, there continues to be a need for systems, methods and/or computer program products that can accurately simulate CMP results. Moreover, conventional simulators may carry out simulations on an integrated circuit chip level of a wafer, rather than over the entire wafer. Because tens or more of integrated circuit chips are repeatedly fabricated with the same pattern in a wafer, the CMP results over the entire wafer may be predicted based on the CMP results with respect to only one chip. However, wafers may be asymmetric due to a flat zone thereof, and/or the different patterns that may exist at the wafer periphery, where integrated circuits are not found.
Embodiments of the present invention can provide systems, methods and/or computer program products that can obtain an effective pattern density of a layer of an integrated circuit from layout data that defines the layout. A grid of pattern cells is defined for the layout data. A respective pattern density is determined for a respective pattern cell in the grid. An effective pattern density is calculated for a first pattern cell in the grid. The effective pattern density for the first pattern cell is a function of the pattern density of at least a second pattern cell in the grid that is remote from (i.e. nonadjacent) the first pattern cell, and a distance of the at least a second pattern cell from the first pattern cell. Adjacent cells also may be included and preferably are included, in the effective pattern density.
In other embodiments, a weighted average pattern density of a plurality of pattern cells in the grid around the first pattern cell and including the second pattern cell is calculated, that is inversely weighted as a function of the respective distances of the plurality of pattern cells from the first pattern cell. In yet other embodiments, the respective patterned densities of the respective plurality of pattern cells is multiplied by a weighted value that is inversely proportional to respective distances of the plurality of pattern cells from the first pattern cell and by the pattern density of the first pattern cell, to obtain a respective weighted pattern density for a respective one of the plurality of pattern cells. The respective weighted pattern densities are summed and divided by the number of cells in the selected plurality of pattern cells, to obtain the effective pattern density of the first pattern cell.
In still other embodiments, the pattern densities may be scaled as a function of fabrication processes that are used to fabricate the integrated circuit. Scaling may be performed by changing a pattern width and/or by multiplying a pattern density by a scaling factor based on the fabrication processes that are used to fabricate the integrated circuit.
Other embodiments of the present invention can determine the thickness of the planarization layer as a function of CMP polishing time, based on the effective pattern density. Moreover, in determining the thickness of the planarization layer as a function of CMP polishing time, at least one of the parameters may vary as a function of location of the integrated circuit in the wafer. These parameters therefore may be determined as a function of the location of the integrated circuit in the wafer.
According to yet other embodiments of systems, methods and/or computer program products according to the present invention, a layout which defines a pattern of the patterned layer is divided into a plurality of pattern cells. A percentage of the pattern occupying area in each pattern cell is computed as the pattern density of each pattern cell. Then, the effects of patterns of peripheral pattern cells on the pattern density of a selected cell are computed, for each of the pattern cells, as a function of the distances of respective peripheral cells from the selected pattern cell, to obtain an effective pattern density for each of the pattern cells based on the computed distances. When CMP is performed on a planarization layer, stacked on the patterned layer, the thickness and/or the step difference distribution of the planarization layer in the integrated circuit in accordance with the polishing time are computed based on the effective pattern density of each pattern cell in which the effects of patterns of the peripheral pattern cells has been reflected.
In yet other embodiments, a pattern may be extended and/or reduced based on the fabrication process that is used for the planarization layer. Accordingly, scaling may be used to evenly extend and/or reduce the pattern prior to computing the pattern density of each pattern cell, or multiplying the pattern density of each pattern cell by a predetermined scaling factor after computing the pattern density of each pattern cell.
In still other embodiments, the thickness and/or the step difference distribution of a planarization layer, which has been computed by an integrated circuit chip level simulation, can be extended to across an entire wafer that includes a plurality of integrated circuit chips. In one embodiment, the relative velocity V of the wafer with respect to a polishing pad, and the pressure P of the polishing pad on the wafer, which can vary in accordance with the position of each chip in the wafer, are computed. The computed parameters are then substituted into an equation used to calculate the thickness of a planarization layer in a chip, so that the thickness and/or the step difference distribution of the planarization layer in each chip of the wafer can be calculated with respect to the positions of each chip within the wafer.
In yet other embodiments, a CMP stop time and/or a monitoring point can be determined, based on the thickness and the step difference distribution of the planarization layer, which have been computed at a chip and/or wafer level. Alternatively, a dummy pattern for compensation of the step difference can be established, so that the results of the simulation can be reflected in the design of the integrated circuit.
Accordingly, the thickness of a planarization layer after CMP can be predicted accurately by using a pattern density which has been calculated in consideration of the effects of patterns of the remote (nonadjacent) pattern cells, and also preferably adjacent pattern cells, as a function of the distances between each cell and the remote pattern cells. Also, the CMP simulation performed at a chip level can be extended to a wafer level.

Systems, methods and computer program products for obtaining an effective pattern density of a layer in an integrated circuit, and for simulating a chemical-mechanical polishing process using the same


An intraocular scissors including a handpiece which supports a detachable assembly having a pair of elongated relatively reciprocable blade members suitable for intraocular surgery. One of the blade members is fixedly mounted with respect to the handpiece and the other is mounted for reciprocating movement. Drive means are provided to operate the scissors in various modes including different rates of movement of the reciprocating blade member.

This invention relates to an improved intraocular surgical instrument which can be used with microsurgical scissors, forceps, knives and the like.
The invention will be described in connection with its preferred usage and that is a microsurgical scissor. Microsurgical scissors are in widespread use during intraocular operations by surgeons worldwide. Three types of driver (actuation) systems for these scissors are in current use: manually operated handles with squeeze-type or lever depression actuation, pneumatic piston linear drivers, and electrical motors of direct current or solenoid drive.
Grieshaber and Co., A.G. of Switzerland produces a wide variety of microsurgical scissors and driver systems including the Proportional Control System (PCS), a Membrane Peeler Cutter (MPC) and manual drive handles (Southerland Style). Pneumatic drivers are produced by Storz Instrument Co. of St. Louis, Mo.; Alcon Surgical, Inc. of Ft. Worth, Tex.; The Dutch Ophthalmic Research Corporation (DORC) of Holland; and TREK Medical of Muckwamago, Wis. Each company provides various scissortips attachable to these drivers, or allow them to cross adapt to other manufacturer's designs. Manual handles are provided by Grieshaber, Alcon, Storz, DORC, TREK and others.
Most intraocular scissors have design similarities in which a pair of cutting blades extend from the end of a tubular needle with one blade being fixed and the opposite opposing blade end being reciprocated between an open and closed position with respect to the fixed blade. This reciprocating movement is accomplished through the action of one of the three above-listed driving systems, i.e. manual, pneumatic or motor.
In the manual driver, actuation of one blade end against the other is through the transfer of movement to the movable blade by depression of a single lever extending from the handle (Southerland-Grieshaber) or by squeezing two opposing platforms on opposing sides of the handle. The movable blade moves through an excursion of 60 to 70 mils (0.060 to 0.070 inch) from the fully open to the fully closed portion during actuation.
In the pneumatic driver, actuation is achieved by pressurizing a piston with a compressed gas source into a chamber within the handle, which causes the piston to move forward against a spring, moving the one blade against the other, closing the blades. Opening the blades is accomplished by movement in the opposite direction through energy stored in the spring, as the gas within the piston chamber is released. Control of the gas pressure release to the piston is accomplished by depression of a foot pedal by the surgeon. Scissor actuation is thus accomplished via footpedal control rather than via finger control, allowing the surgeon to hold the instrument steady without inducing any unnecessary tremor or motion to the blades due to finger movement. The footswitch is a linear depression switch which also allows selection between a "proportional cut" mode versus a "multicut" mode by the manufacturer. In the "proportional cut" mode, the scissors blades close at a rate and position directly related to the rate and position of depression of the pedal, e.g. one-half depression of the pedal will close the scissors half way, full depression will close the scissors fully, etc. The scissors will move open and closed inducing a cutting force only as the footpedal is depressed and released, with a more rapid depression resulting in a more rapid closure, etc. A full depression of the footpedal by the surgeon closes the blades to reduce the width of the scissor blade profile so that it can be inserted through a small slit, e.g. 1.0 mm slit, in the eyeball. Once within the eyeball, the scissor blade can be opened and closed by the footpedal action described above. To remove the scissors from the eyeball, the blades are fully closed by complete depression of the footpedal to again reduce the scissor width. In the event of failure of the piston driver while it is in the eyeball, the surgeon can manually close the scissors in this emergency situation by screwing a thumbscrew down on the driver to allow its safe removal from the eye. While the scissors are in the eye, the surgeon can select the "multi-cut" mode by the temporary lateral motion of the footpedal. Depression of the pedal in this mode causes movement of the blade from its open to its closed position and back to its open position repetitively at a rate of approximately one stroke per second. A slight depression of the footpedal activates this multiple repetition mode, which continues at the same rate regardless of the amount of depression to the pedal. The surgeon returns to the "proportional cut" mode and fully depresses the pedal to fully close the scissor blades and holds them closed to remove them from the eye.
Motor drivers of either rotary or linear solenoid style activate scissor closure by controlled transfer of the motor energy to the movable blade. The MPC is an automated solenoid-style microscissors that has a nondetachable pair of cutting blades extending from the end of a tubular needle, with the outer blade end being fixed and the inner blade end being reciprocated between an open and closed position with respect to the fixed blade. A first footswitch is operated by the surgeon to move the movable blade to a closed position reducing its profile allowing its introduction into the eye. Once inside the eye, the first footpedal is released and the movable blade snaps open due to energy stored in a spring within the driver handle. Depression of a second footpedal causes the blades to move from an open position to a closed position against a spring, and then back to an open position. The scissors always default to an open position during activation of the second footpedal. The blade excursion is again 60 to 70 mils (0.060 to 0.070 inch) and travels at a rate of 1000 mm/sec from the open to the closed position. The moving blade cuts in about 5 milliseconds and remains shut for about 15 milliseconds before automatically returning to the open position. The MPC can also be operated in a "single cut" mode versus a "multicut" mode. In a single cut mode, depression of the second footpedal results in one excursion of the movable blade and one resulting cut. Release and redepression of the second footpedal is required to initiate a second excursion and cut. In the "multicut" mode, hereinafter referred to as an oscillation or oscillatory mode, the blade moves through a series of repetitive cuts or oscillations at a rate of one to five strokes per second, with each stroke traveling at 1000 mm/sec. These oscillations continue While the second footswitch is held in the depressed position. This MPC microsurgical scissor is gas sterilizable and is not recommended to be steam autoclaved, except in "emergency situations", as would be desirable for an intraocular scissor.
In the PCS-Grieshaber system, there is a power operation and control of a variety of Southerland intraocular instrument tips including a scissor by energy from a DC motor within the handle. This PCS system includes movement of the cutting blade in either the "single" stroke cutting mode or a continuous oscillatory motion mode. Manual selector switches allow choice between these modes, as well as selection of the rate of scissor closure for either mode, and the rate of oscillations in the oscillatory mode. Additionally, a manual dial switch allows the opening distance between the radius of curvature of the blades to range from 1/3, 2/3 or full.
In the MPC automated microscissors and in some other Southerland and manual scissors, the scissor tip is of the vertical design in which the outer fixed blade has a cutting edge substantially parallel to the cutting edge of an inner movable blade such that the cutting edges cut on a substantially straight line on a guillotine principle. The surfaces are not perfectly parallel, however, and do have some angle between them, creating a cutting point where the blades are in contact. The MPC scissors close so quickly, however, that their cutting point is effectively a straight line rather than a single point as in conventional angled scissors described below.
Shear is a force responsible for division of the tissue held within the scissor blades regardless of their design, and describes a vector perpendicular to the vector of movement of the direction of closure to the blades. The strength of the force vector pushing the blades one against the other is responsible for the creation of the shear force vector.
Guillotine or parallel blade scissors tend to crush the tissue between the blades before the shear begins to divide the tissue. This crush action has an advantage of holding the tissue within the blades and preventing forward thrust of the tissue out from the blades. It has a distinct disadvantage, however, of creating crush artifact in the tissues due to tissue deformation that occurs prior to its shearing, as illustrated in FIGS. 25 and 26 hereinafter. Due to motion of the scissors between cuts and the inability to begin a cut immediately in the exact same position as the ending of the previous cut, the tissue is engaged in a slightly different location, resulting in steps or shoulders between cuts and also in curved or scalloped surfaces on the cut tissue wall, as shown in FIGS. 25 and 26. Parallel or vertical-style scissors manually driven exhibit the same tissue sectioning artifacts as the MPC microsurgical scissor and is shown in FIG. 22.
Angled or horizontal-style scissors can be manually or automatically driven depending on the manufacturer, but the cutting characteristics are similar, and different from vertical scissors. In angled scissors, the blades pivot from a fulcrum point and create a single cutting point where the blades are in contact. When the blades are fully open, this point is closest to the fulcrum and successively moves forward down the scissor blades toward the tip as the scissor closes. The blades also become relatively more parallel as they close and begin to induce some crush action near the tip.
As the forward movement of the cutting point proceeds toward the tips of the blades it induces a forward thrusting motion to the tissue due to the resistance of the tissue being sheared, thus serving to push the tissue ahead of the scissor as it closes. Also, a greater area of tissue is included between the blades during closure, further increasing tissue resistance and thus contributing to increased forward thrust. Forward thrust of tissue during ocular surgery is annoying and clinically undesirable as it contributes to irregular cuts and longer procedures. Needing to "chase" the target tissue puts additional traction on surrounding normal tissue and contributes to tears and accidental cuts within the normal tissue.
With a force applied about the fulcrum of the scissors blades the shear forces are at a maximum when the cutting point is nearest to the or fulcrum point of the blades. The blades will stay together with the greatest force near the pivot and thus shear is maximum here. Further, less force is required to close the blades to create this shear force when the cutting point is near the pivot. As the cut proceeds and the cutting point moves farther from the pivot, mechanical advantage is lost, greater forces are required to close the blades, shear force is lost and the scissor blades may actually be pushed apart at the tips if the tissue resistance force becomes greater than the shear force.
In order to maintain a force pushing the blades together at the cutting points, the blades are positioned against each other by two opposing forces called camber. The radius of curvature of the camber increases along the length of the blade, to create more shear force at the tip to try to overcome some of the loss of shear force due to the loss of mechanical advantage, as shown in FIG. 29.
In cross section, scissor blades are actually asymmetric wedges opposed to each other, and each want to drive into the tissue at an oblique angle called the "preferential wedge path" (FIG. 30). The camber and closing movement of the blades want to drive the blades into the tissue 60.degree. to 90.degree. away from the wedge path (FIG. 31). The resulting actual movement of the blade is more of a twisting motion as shown in FIG. 32. Because the tissue has resistance to shear, it too will be twisted, more or less by the twisting motion of the blades with softer and thicker tissues twisting and deforming more than harder and thinner tissues. The resulting cross sectional cut has an "S" shape rather than being perpendicular to tissue surface, as shown in FIG. 33. Ocular tissues are usually soft enough to result in "S" shape cuts by conventional scissors, which is less desirable due to its irregular surface, as shown in FIGS. 23 and 24.
As more of the blade surface becomes buried within the tissue during the cut, the lateral resistance increases, preventing a side-to-side motion or a "steering" redirection to the scissors. If the scissors are wide open, the lateral resistance is at a minimum and the scisors can be steered to a new location without distortion induced by lateral resistance.
Every microsurgical scissor currently available for ocular surgery has more or less of the following disadvantages dependent on its individual design: (1) forward thrust during closure pushes the target tissue out of the scissor because of forward motion of the cutting point; (2) crush artifact deforms the tissue during shear; (3) irregular "S" shaped cross-sectional cuts occur, the severity of which is determined by individual ocular tissue characteristics; (4) loss of mechanical advantage during closure causes loss of shear, creating tissue incarceration at the tips, and resultant lateral crush artifact; and (5) increased lateral resistance during closure prevents re-direction of the scissor along a curved line without creating crush and distortion artifact into the cut.


Successive approximation register (SAR) analog-to-digital converters (ADCs) generally employ capacitive digital-to-analog converters (CDACs) to perform data conversions. In these CDACs, matching of capacitive values is important, and for conventional high resolution SAR ADCs, complex trimming or calibration procedures can be too costly. Here, however, a SAR ADC is provided that performs error correction so as to reduce the overall cost compared to conventional SAR ADCs.

A typical successive approximation register (SAR) ADC includes capacitive digital-to-analog converter (CDAC) for performing a successive approximation of a sampled input signal. The CDAC includes an array of capacitors, where each capacitor can be assigned to a bit of the digital output word of the SAR ADC. Generally, the capacitors can be commonly coupled at a common node, which can be coupled to an input of a comparator. During each conversion step, the comparator 110 are its input signals and provides a bit of a digital output word to a control stage or SAR controller. Each of the capacitors of the CDAC are then switched in accordance with the comparison result.
Additionally, the capacitors of the CDAC may be further subdivided in to two or more stages. For example, there may be a first stage or main CDAC that includes capacitors relating to the most significant bits (MSBs) of the digital output word of the SAR ADC and a second stage or sub-CDAC that includes capacitors related to the least significant bits (LSBs) of the digital output word of the SAR ADC. There may also be a serial capacitor coupling the main CDAC and the sub-CDAC for scaling the two stages for approximation steps relating to the MSBs and the LSBs, respectively. The absolute capacitance values in the two stages may also be almost similar. However, in order to achieve high resolution, and good linearity, the matching of the capacitance values is important.
With the typical matching constraints of capacitance values in a semiconductor (e.g., CMOS) technology, a resolution of the SAR ADC of about 10 to 12 bit can be achieved. For higher resolution the capacitors mismatch has to be adjusted. The digital output word of the SAR ADC can be digitally corrected by adding or subtracting digital correction values in order to compensate static mismatch of the capacitance values. However, this approach is only applicable as long as the successive approximation process converges. Convergence generally means that at the end of the conversion procedure, a voltage difference at the comparator input is equal to or smaller than the value that corresponds to an LSB. If mismatch becomes too large, digital correction becomes impossible. Therefore, the capacitance values in the main CDAC have to be physically trimmed after production in order to achieve improved matching and to guarantee convergence of the successive approximation process. Ideal convergence generally means that the voltage difference between the comparator inputs corresponds to a value that is smaller than +/−½ LSB. The capacitors in the sub-CDAC (relating to the LSBs) are usually not trimmed after production of the integrated circuit.
There are several different principals which can be applied for trimming the capacitors of the main-CDAC. One is based on laser trimming, where capacitor values are added or subtracted from the capacitor array by use of laser beam, which removes connections in a prior assembly step. Another principle is based on adding or subtracting capacitors to and from the capacitor array based on setting switches and storing the appropriate states of the switches in a memory. Both techniques may use a self calibration procedure which aims to determine the amount of mismatch of the capacitors indicating the capacitance values which are to be added or subtracted from the capacitors of the main CDAC. However, both trimming and calibration procedures require a rather complex production step, which increases production costs. Furthermore, the trimming process for correcting the capacitance values of the main CDAC based on switches and capacitors and a memory requires a large amount of additional chip area for the switches and the memory.
U.S. Pat. No. 6,747,589 generally discloses a dynamic error correction step for an SAR ADC in order to increase speed and reduce current drive requirements of the SAR ADCs. The basic idea consists in testing a bit decision as to whether or not the error is below a maximum admissible limit. Testing and correction is performed quasi-simultaneously by selectively coupling one or two additional correction capacitors of the same size as the capacitor of the tested bit. The two additional correction capacitors are switched between the reference voltages in order to add or subtract a charge value to the network, which is equivalent to a certain bit capacitor and the output of the comparator is used as an indicator of the error. The correction capacitors provide that the successive approximation process converges. However, the digital output word of the SAR ADC is corrected by adding or subtracting single bits corresponding to the corrected position and the mismatch of the capacitance values of the capacitors is removed by trimming procedures as described above.
There are more and less significant bits in a digital output word of a SAR ADC, and corresponding more or less significant capacitors in the CDAC. The significance of a capacitor is not strictly related to its capacitance value, but rather to its contribution to the voltage level on the comparator input (common node). This contribution can be considered as a difference voltage or voltage step ΔV on a node, typically on the common node. The more significant bits of a digital output word are determined earlier than less significant bits during the successive approximation process. Therefore, the capacitor(s) are also used in order of their significance starting with the most significant capacitor and ending with the least significant capacitor(s).
In an integrated circuit or IC, the maximum and the minimum physical size of a capacitor is limited. The upper limit is due to chip costs due to chip area and the lower limit due to technological boundaries, as minimum structure size and parasitic effects. Therefore, the minimum and maximum capacitance value of a capacitor should remain within reasonable limits.


Provided is a method comprising reacting the anionic living end of a polymer that is end capped with a steric hindering compound with a carbonyl-containing compound to produce a polymer with a homolytically cleaveable group. An engineered plastic may then be produced by adding the polymer containing a homolytically cleavable group to a solvent comprising at least one vinyl monomer; (b) optionally adding at least one additional inert solvent; (c) optionally adding additives selected from the group consisting of extender oils, modifiers, and antioxidants; and (d) initiating polymerization of the at least one vinyl monomer by the use of an initiator and/or heat, wherein a free radical is produced from the polymer containing a homolytically cleavable group.

Copolymerization is one of the most widely used techniques in the polymer industries. For example, polystyrene is one of the largest volume thermoplastic resins in commercial production today. However, homopolymer polystyrene resin is typically a brittle resin having a poor impact strength, and is only suited to applications where its brittleness is acceptable. It has long been known that impact strength of polystyrene can be greatly improved by the blending/grafting of rubbery particles dispersed throughout the polystyrene matrix. Polystyrene resins of improved strength achieved by incorporation of rubbery particles are often referred to as high impact strength polystyrene (HIPS).
The physical characteristics and mechanical properties of HIPS are dependent upon many factors, including rubber dispersion and rubber morphology. For example, when HIPS polymers are formed by incorporation of polybutadiene (PB) phase in polystyrene (PS) through the in situ formation of PB-graft-PS, phase separation begins early in the polymerization because of the immiscibility of the rubber within the polystyrene being formed and the depletion of the styrene phase. The immiscibility of PB in PS and the in situ formation of the compatibilizer, PB-graft-PS, gives rise to the formation of varied morphologies of the lamellar, globular, capsule, and other types. These microstructures are responsible for the absorption of energy when the material is subjected to high intensity (impact) or low intensity (tension) forces.
Copolymerization of styrene and butadiene is also necessary in preparing other rubber modified styrenic polymers such as as high impact polystyrene, styrene-maleic anhydride copolymer, methylmethacrylate-butadiene-styrene (MBS) copolymer, transparent impact polystyrene, and acrylonitrile butadiene styrene copolymer (ABS). ABS resin generally comprises a rigid matrix copolymer phase of styrene and acrylonitrile monomers having dispersed therein a graft copolymer of a butadiene rubber substrate grafted with the styrene/acrylonitrile copolymer. ABS resins are most often produced by initially preparing a polybutadiene seed latex and copolymerizing styrene and acrylonitrile in emulsion in the presence of the seed latex.
The copolymerization of styrene and polybutadiene to produce HIPS, ABS, and MBS typically is conducted via free radical polymerization between the styrene and polybutadiene. Free radical polymerization is typically initiated by the use of an initiator.
U.S. Publication 2006/0241265 discloses a method for converting an anionic living end of a polymer to a protected free radical "living" end. The polymer having a protected free radical "living" end may be used in the copolymerization of styrene and butadiene. Furthermore, U.S. Publication 2006/0241265 discloses that the polymer having a protected free radical "living" end may be reversibly coupled, such that upon decoupling, a free radical is generated for further copolymer chain reaction.
Advantageously, the present invention provides a novel method of copolymerization that involves reversibly coupling a polymer having a protected free radical "living" end by using a carbonyl-containing compound.

Method for generating free radical capable polymers using carbonyl-containing compounds


Dust emissions can be reduced in a metal or slag casting apparatus by providing an endless conveyor having a plurality of casting molds with upper open tops wherein the conveyor is arranged to move the casting molds in a first section from a casting station to a discharge station and in a second section back to the casting station. The method for reducing dust emissions includes (a) providing a casing forming a bottomless box over at least part of the first section of the conveyor, (b) injecting within the casing a gas on the surface of the mold with an angle configured to blow off loose, solid particles, formed at the surface of the metal, during early stages of the cooling down and to start the solidification of a superficial layer of metal or slag, and (c) extracting the gas and the solid particles by suction from within the casing.

As it is well known within the art, liquid hot metal is either poured directly out of the bottom of the blast furnace through a trough into a ladle car for transfer to the steel mill. If it cannot be processed directly, it is cast in the form of ingots, so-called pigs, for storage or for further transport.
Nowadays, so-called pig casting machines or apparatuses are used for manufacturing said pigs of pig iron. They conventionally comprise a casting station, at least one endless conveyor with a plurality of casting molds, as well as a removal station at the discharge point of the endless conveyor.
When reaching the casting station, the (empty) casting mould is filled with liquid hot metal and is conveyed to the discharge point. The conveying path and/or conveying time of the metal within the casting machine must be chosen such that the liquid metal in the respective pig casting mould is essentially solidified before reaching the discharge point. In order to accelerate the solidification process of the liquid hot metal and to thereby reduce the required length of the conveyor, the pig casting machines generally further comprise an active cooling zone at some distance of the casting station and before the discharge point. In this active cooling zone, the casting molds and/or the metal inside are generally cooled with water, either from the sides or beneath the molds or from above, or using any combination thereof. Examples of casting machines with active water cooling zone(s) are described e.g. in U.S. Pat. No. 4,605,055, in JP 4 052050 or in FR 1 302 669. When passing through the discharge point, the casting molds either automatically empty by tilting over an inversion point or the pigs are removed by means of a corresponding device.
During the slow solidification of a Fe-C alloy containing more than 4.3% C (i.e. a hypereutectic composition), such as pig iron, part of the carbon is pushed out of the liquid matrix and forms light, flyable particles named "graphite kish" or "carbon flakes" on the surface of the solidifying metal. This is especially true while casting metal out of a blast furnace (C=4.3%-5.1%). Because of their light weight, these graphite particles can fly everywhere, in and around, the workshop and can be a concern in term of industrial hygiene and environmental protection.
Furthermore, the graphite particles still remaining on the surface of the pigs when entering the active cooling zone in the upper part of (a first section of) the conveyor are lifted off by the steam formed when the cooling water comes in contact with the hot metal which leads to a further dissemination of the graphite particles around the plant.
At least, in theory, the phenomenon of flaking out can be avoided if the solidification speed is sufficient enough to freeze the liquid composition in its initial state. In practice however, this is rarely possible due to the size of the pigs.
Although graphite kish formation is a particular issue during pig iron casting, the dust formation during casting of other metals or slags may also be a concern. The dusts in all these cases may take their origin in the smelting of the metal itself, in the pouring of the molten metal in the casting station or during reaction with the ambient atmosphere, such as slag and dross residues, fine solidified particles of metal and metal oxides, etc.

Dust emission reduction during metal casting


A locking member for a loose-leaf binder includes a member having an integrally pivoted portion pivotally mounted in a first actuating member, an engaging projection which engages with an engaging recess of a second actuating member to prevent movement of the second actuating member. An elastic portion which abuts against an upper surface of a first base plate to urge the engaging projection to the engaging recess, first finger hooking portion, whereby under a condition where the binder rings are closed, movement of both the base plates are prevented against an opening forces acting upon the binder rings. When first finger hooking portion is pushed toward second finger hooking portion, the engaging projection is disengaged from the second actuating member against the elastic force of the elastic portion, and both of the base plates are then moved in such directions as to open the binder rings.

1. Technical Field of the Invention
The present invention relates to a loose-leaf binder of a type in which binder rings are elastically opened and closed by actuating members, and more particularly, it relates to a loose-leaf binder with a lock to eliminate an accidental detachment of leaves owing to unintentional opening of binder rings during transportation, exhibition and storage.
2. Prior Art
Quite frequently, experienced are accidents of dislodgement of leaves of loose-leaf binders due to unintentional opening of binder rings caused by vibration or shock exerted in operation for transportation, reshipment, exhibition, storage or the like. In order to eliminate such an accident, the inventors of the present application have proposed a loose-leaf binder with locking means in Japanese Patent Publication No. 88,680/1993. Describing briefly, as shown in FIGS. 1 to 4 the disclosed loose-leaf binder includes a first and a second base plate 1 and 2 abutting against each other on their inner sides and each having a plurality of semicircular binder rings 3 and 4 adapted to abut against each other, an elastic metal sheath 7 restraining outer edges of both the base plates 1 and 2 to permit the binder rings 3 and 4 to open and close by elastic upward and downward movements of the base plates 1 and 2, and a first and a second actuating member 10 and 11 each mounted at one end of the base plate 1 and 2 to intersect each other and having a finger hooking portion 17 and 16. The first actuating member 10 fixed to the first base plate 1 includes an engaging projection 15, while the second actuating member 11 is pivotally connected to a shaft 14 at the corner of the lower end of the second base plate 2 and has an engaging portion 18′ which can be engaged with and released from the engaging projection 15 by the pivotal movement of the second actuating member 11 in its locking and unlocking directions, respectively.
In the loose-leaf binder with the lock, after both the binder rings have been closed in opposite directions by fingers, the second actuating member 11 is pivotally moved from a state of FIG. 4 to a state of FIG. 1 to engage the engaging projection 15 with the engaging portion. Under this condition, there is not any risk that the binder rings unintentionally open and the leaves are dislodged therefrom owing to vibration or shock exerted in operations such as transportation, reshipment or exhibition of the loose-leaf binders in which the leaves are bound. On the other hand, when some bound leaves are replaced with others or another handling is done, the finger hooking portions 16 and 17 of both the actuating members 10 and 11 are pushed in opposite directions by fingers to move both the base plates 1 and 2 from their lower positions to their upper positions, whereby the engaging portion 18′ can be disengaged from the engaging projection 15 only by a push operation with the fingers when the binder rings 3 and 4 are opened. Therefore, the above binder is excellent in operability.


A panel mounted electrical connector is disclosed in combination with an equipment rack, multiple units of electronic equipment arranged in the rack, each unit having a connector in mating engagement with the connector mounted on the back panel of the rack. The panel mounted connector is arranged to align and hold in proper position multiple connectors, thereby forming a composite connector that mates with a mating composite connector on the unit of electronic equipment. Cutouts are provided in a surface of the composite connector so that cabling that is terminated to the connector may exit the connector at right angles thereto substantially parallel with the back panel.

It is common practice in the industry to individually mount connectors to the back panel, or back plane of an equipment rack. In doing this care must be taken to assure that the individual connectors are in proper alignment so that when the drawer containing the unit of equipment is inserted into the rack, the connectors of the unit properly mate with the connectors mounted to the back panel. Additionally, when the connectors are mounted to the back panel on the unit side, the interconnect cables must exit the connectors through openings cut through the panel. What is needed is a connector that is a composite of the connectors that are required by a particular unit of equipment so that these connectors are automatically held in the proper alignment with respect to one another and a provision for exiting the interconnect cables without the need for openings in the back panel.

Electrical connector for back panel mounting


A container for holding a plurality of magazines, includes a first side wall having a first bottom edge, a first rear edge, a first top edge and a first front edge; a second side wall having a second bottom edge, a second rear edge, a second top edge and a second front edge; a bottom wall connecting the first and second bottom edges of the first and second side walls together; a rear wall connecting the first and second rear edges of the first and second side walls together; the bottom wall and the rear wall maintaining the first and second side walls in substantially parallel, spaced apart relation; the first and second top edges of the first and second side walls being unconnected with each other; and the first and second front edges of the first and second side walls being unconnected with each other; wherein side walls of a first such container fits within side walls of a second such container with a friction fit.

This invention relates generally to magazine and paper holders and, more particularly, is directed to a nesting magazine organizer.
Open ended containers for holding and organizing magazines and other papers are well known. Such containers are formed with parallel, spaced apart side walls connected by a bottom wall, a rear wall, and either a front wall or a top wall. If a top wall is provided, access is attained through the front of the container, and if a front wall is provided, access is attained through the top of the container. The side walls have dimensions generally at least as great as the magazines to be received therebetween, and are made of a sturdy plastic, cardboard or like material.
As with most containers, a problem occurs during shipping of the containers. Specifically, because of the free space between the side walls, the containers occupy an undue amount of space when shipped. This results in an increase in the shipping cost of the same, particularly when shipping thousands of such containers.
U.S. Pat. No. 776,042 to Acheson discloses a packing and display box which is used for storing and displaying bluing devices in the form of sticks. The box is formed in two halves which are Joined together by nails during shipping and are separated into the two halves for display thereafter. The two halves can each be used for displaying the sticks. However, the two halves, when joined together, are flush with each other, thereby requiring the aforementioned nails to temporarily secure the two halves together during shipping.
U.S. Pat. No. 1,065,922 to Cutler discloses a receptacle formed of two halves which are hingedly connected to each other. However, only one of the halves is used for storing materials, and the other half is used as a cover.
German Offenlegungsscrift No. 1,486,241, which was filed on May 6, 1965 and published on May 29, 1969, discloses a packaging container of foam plastic, with a base and side walls designed so that containers can be stacked one on top of the other, and aligned with others alongside. The construction, however, requires a relatively complicated configuration, with edges thereof formed with a zig-zag type shape in order to intermesh with each other.
French Patent No. 1,253,068 discloses a container having two identical separable parts which are held together by tongue-type connectors. In this manner, the positioning of the tongues must be precise in order to obtain a secure fitting of the separable parts. The tongues therefore increase the manufacturing costs and complexity of the container.
Lastly, U.S. Pat. No. 3,952,903 to Sanders et al. discloses another container held together with snap fasteners.


A door panel that is capable of maintaining the adhering strength of the adhesive is provided. An outer panel and an inner panel are joined together by an adhesive. Adhesive retaining portions, each of which includes an adhesive retaining channel for retaining the adhesive, are provided in adhering portions of the inner panel. Each adhering portion includes vertically extending portions, and the adhesive retaining portions of the inner panel are formed in the shape of an extended raised portion and extend vertically in the respective vertically extending portions of the adhering portions, along ventilation openings, which are formed at locations corresponding to groups of ventilation holes of the outer panel. Each adhesive retaining portion is provided at the middle of each vertically extending portion of the adhering portions so as to be flanked by adhesion margins of identical width.

FIG. 18 illustrates a hydraulic excavator 10, which is a work machine. The hydraulic excavator 10 includes a lower structure 11, an upper structure 12, a cab 13, a work equipment 14, and a power system 15 that includes an engine. The cab 13, the work equipment 14, and the power system 15 are mounted on the upper structure 12, which is rotatably mounted on the lower structure 11. The power system 15 is covered by a top cover 16, side doors 17,18, and other such components. The side doors 17,18 are mounted by hinges, which will be explained later, so as to be capable of opening and closing, and secured in the closed state by means of a latching device 19.
Examples of conventional side doors 17,18 of a work machine include a door panel with a double-panel structure including an outer panel and an inner panel. When producing such a door panel, the inner panel is fixed to the outer panel by the adhering strength of an adhesive, and the adhering surfaces of the outer panel and the inner panel to which the adhesive is applied are uniformly flat surfaces (e.g. See Japanese Laid-open Patent Publication No. 9-228412 (page 3, and FIG. 7)).
As the adhering surfaces of the outer panel and the inner panel of the conventional side door described above are flat surfaces, the adhesive may become completely flattened at some areas where there is little remaining adhesive, resulting in reduction in the adhering strength of the adhesive.
This presents a particularly serious problem in the case of a door designed with high-heat tolerance, because such a door requires openings, and the region around the openings is prone to not only reduction in the strength but also reduction in the remaining area of the adhering surfaces, making it difficult to maintain the adhering strength of the adhesive and impairing the integrity of the entire door panel.
In order to solve the above problems, an object of the invention is to provide a door panel that is capable of maintaining the adhering strength of the adhesive. Another object of the invention is to provide a door panel that includes openings for high-heat resistance and is capable of maintaining the adhering strength of the adhesive and preventing reduction in the strength around the openings.