An exposure apparatus includes a projection device for projecting a pattern drawn on a surface of a master, a stage apparatus which moves at least a substrate of the master and a substrate relative to the projection device, and an exposure device for repeatedly exposing the substrate to the pattern of the master. A plurality of pipes connected to movable units of the stage apparatus are joined to each other at partial outer surfaces of the pipes and constitute an integrated pipe array. Electrical cables or signal line cables connected to the movable unit pass through hollow portions of some of the pipes serving as the integrated pipe array.

FIGS. 1A and 1B are views for explaining the prior art of the present invention and show X and Y piping assemblies on a wafer stage and cross sections of the X piping assembly, respectively.
As shown in FIGS. 1A and 1B, a pressure air system comprises pressure air pipes 120a to 120e, which supply pressure air. A vacuum system comprises vacuum pipes 120f and 120g, which supply chuck vacuum air for a wafer 109 and chuck vacuum air for a wafer chuck 108. A coolant system comprises coolant pipes 120h and 120i, which supply/recover a coolant. An electrical system comprises electrical cables 120j and 120k, which supply signals and driving currents among an illuminance sensor 112 on a fine adjustment stage 107, a photosensor within a stage reference mark 113, and driving units. A Y piping assembly 121 has almost the same arrangement as that of an X piping assembly and aims at movably connecting pipes in the Y direction. A pipe coupling wire 122 binds the piping assemblies of the respective systems to connect the pipes 120a to 120g of the pressure air and vacuum systems, the coolant pipes 120h and 120i of the coolant system, and the electrical cables 120j and 120k of the electrical system in almost a belt-like manner. A piping assembly of this type and an arrangement based on the same concept are disclosed in Japanese Patent Laid-Open No. 11-030294.
However, in the above-mentioned prior art example, the pipes of the systems are separately connected to a stage movable unit. When the stage movable unit moves, the pipes of the systems may rub against each other, may warp at an indefinite position, or may warp at the pipe coupling portion. Disturbance from the connecting portion of each piping system may decrease the control accuracy of a stage.
When a stage apparatus is used in a low-humidity environment, such as a nitrogen-purged atmosphere or a vacuum, movement of the piping system connecting portions tends to generate static electricity to charge the surfaces of the respective piping members. An electrostatic spark may occur at an indefinite position between the pipes or between components on the stage apparatus to damage the pipes, the electrical cables, and the components of the stage.
The present invention has been made in consideration of the conventional drawbacks, and to provide an exposure apparatus capable of minimizing disturbance by a piping system connecting portion, dust, and electrostatic buildup on the surfaces of piping members.


A steerable bow thruster (12) system is located substantially within the pontoons (20) of a semisubmerged vessel (10) exclusive of a rotating nozzle (42) which is located on the upper side of the pontoons. The rotating nozzle can turn in any direction and allows the steerable bow thruster system to thrust forward, aft and side to side and in any direction in between to allow the semisubmerged vessel to maneuver freely and without the assistance of the main engines. To minimize draft and to prevent ecological harm, the nozzles are installed on top of the pontoons allowing the pontoons to act as a barrier to keep thrust wash from disturbing shallow ocean bottoms and reefs over which the vessel may be operating. The propelling means may be shrouded to prevent harm or injury to swimmers who may be in the water. A rudder (44) may also be coupled to the thruster nozzle to provide directional control for the semisubmerged vessel when it is underway at higher speeds. The nozzle of the propelling means may be located forward of the center of lateral resistance of the semisubmerged vessel.

1. Field of the Invention
This invention relates to semisubmerged, small water plane area twin hull (swath) ships, specifically to steerable bow thrusters which draw seawater in from the sides of the pontoons, and discharge it from a steerable nozzle on the top of the pontoons. The nozzles are directional, and allow the swath to remain in one place without anchoring, also known as station-keeping.
2. Description of Prior Art
Small water plane area twin hull (swath) vessels, also called semisubmerged vessels, have been developed for improved motion, seakeeping and performance characteristics in high sea states. Many U.S. patents including U.S. Pat. No. 234,794 to Lundborg (1880), U.S. Pat. No. 3,063,397 to Boericke (1962), U.S. Pat. No. 3,623,444 to Lang (1971) and U.S. Pat. No. 4,174,671 to Seidl (1979) have been granted which disclose ships of this configuration.
Each of the configurations noted includes submerged pontoons that are parallel to each other and the design water line, vertical struts of reduced waterplane area, and an upper bridging deck. The above patents show a number of configurations for swath vessels.
Thruster systems have been developed for maneuvering and/or propelling a marine vessel by means of pump, tunnel prop, pipe and valve arrangements which take water in from the sea and discharge the water through outlets located in the boat hull so as to achieve the desired propulsive or turning effect. Such systems, as described for example, in U.S. Pat. Nos. 3,517,633, 4,056,073, and 4,214,544 typically employ pipes of various cross sections which curve or join other pipes or nozzles to form the water transport path. Thruster systems have also been developed which employ propellers of many types including screw, cycloidal or shrouded impellers on drive units that extend out of the vessel's hull as shown in U.S. Pat. Nos. 4,294,186 and 4,732,104.
All of these systems designed for conventional monohull vessels employ the bottom or side of the hull for locating the propulsive device. The swath hull form provides a new alternative that is superior for a number of reasons. The new alternative is to locate the propulsive device on the top side of the submerged pontoons. By locating the propulsive device on the top side of the submerged pontoons rather than on the bottom side, the draft of the vessel is minimized and damage to the propulsive device is eliminated in the event of grounding. In shallow water, the water on the top side of the pontoons is also likely to have less foreign matter that can foul or damage the propulsive device than the seawater on the bottom side of the pontoons due to its distance away from the sea bottom.
Conventional monohulls today employ rotatable propellers which extend downward from the bottom of the hull. Pursuant to the advancements disclosed in this patent an improvement of that system for swath vessels would be to invert the outdrive unit and attach it to the upper side of the submerged pontoon. Conventional monohulls today also employ tunnels with pumps or shrouded propellers which pull water in from the sides and discharge it out the bottom through a grating with louvered vents. The grating can be rotated to direct the thrust in approximately the desired direction. The direction is approximate because of the sharp change of direction the water must make through the relatively inefficient vents. Much of the thrust is spilled downward instead of aft, forward or athwartship. In accordance with the ideas advanced in this patent this system would also be improved for swath vessels by inverting the discharge and directing it out the top of the pontoon.
For a swath vessel operating in shallow draft areas, additional advantage is gained with respect to environmental impact. The environmental community has recognized the biological and ecological importance of the ocean bottom and the negative impact of sediment transport due to propeller wash. This is particularly relevant for vessels operating in and around shallow tropical reefs. Locating the propulsive device on top of the pontoons for swath vessels moves the propeller wash well away from the ocean bottom and even provides the pontoon itself as a barrier between the propeller wash and the ocean bottom greatly reducing and even eliminating the adverse environmental impact.
This advantage is even more apparent when one considers a vessel that is carrying snorkel and scuba divers to a shallow tropical reef. Such a vessel is discouraged from employing anchors due to the damage they will inflict on the fragile reef. Presently, permanent moorings are sometimes installed on reefs to allow vessels to visit, but they involve a substantial effort and expense to install and maintain. They are also of limited value to larger vessels due to the limited strength of the coral formations and coral substrate to which the moorings are attached.
The ideal solution for these vessels would be to not attach to the reef in any way whatsoever but rather station-keep above the reef. A vessel is station-keeping when it is maintaining a single location without mechanical attachment to the seafloor usually through the use of thrusters. Presently, many vessels without thrusters will drift with the wind and current for a period of time and then occasionally motor back to the area of the dive group. Ideally, the vessel would be under control at all times and either station-keep over one particular spot on the reef or slowly follow the dive group as it swims across the reef. For larger vessels, use of the main engines for this purpose is usually not satisfactory as the propeller wash would disturb the sediment on the ocean bottom reducing visibility. Any vessel using exposed propellers also endangers swimmers or divers in the water with the rotating propeller blades. Additionally, the use of the main propulsion engines to station-keep or maneuver the vessel with top speeds up to two knots would not be a very efficient use of engines that are designed to move the vessel at much greater speeds.
A conventional monohull with a rotatable bow thruster fitted to the bottom would station-keep but would still have the problem of propeller wash disturbing the sediment and reducing underwater visibility. Depending on the specific propulsive device utilized, rotating propellers may also pose a hazard to swimmers and divers. Pursuant to the ideas disclosed in this patent, a swath vessel with the propulsive device mounted on top of the pontoon would not at any time disturb the bottom sediments. By shrouding the propulsive device, danger for swimmers and divers would also be eliminated.
Mounting of the propulsion device on top of the pontoon rather than on the side has additional mechanical benefits. Top mounting of the propulsion device allows thrust in any horizontal direction by simply rotating the propulsive unit about a vertical axis. If the propulsive unit were installed on the side of the pontoon, the thrust would be limited to fore and aft direction with no athwartship capability unless additional range-of-motion capability were added to the propulsion device. Additional range-of-motion capability would inherently be more complex leading to additional hardware and sealing problems. Also, installation of a propulsion device on a side of a pontoon limits the thrust to only one side of the pontoon. On a two pontoon swath, a side installation would make only one of two thrusters available for athwartship movement.
The advancement described in this patent has additional features. Shrouding the propulsive device and ducting the thrust through piping provides the greatest level of safety for swimmers and divers. Seawater intake or suction drawn from the side of the pontoons will allow a swath vessel to maneuver even if it is temporarily ballasted up so that the upper side of the pontoons are clear of the water. Sea water intakes on the side and a rotating nozzle on top of the pontoon for the sea water discharge as opposed to a rotatable propeller will eliminate cavitation or emmersion of the propeller in a seaway.

Steerable bow thruster for swath vessels


A process cartridge of an image-forming apparatus including a cartridge frame, first and second plates assembled to both sides of the cartridge frame, and first through fourth guiding protuberances arranged on both sides of the cartridge frame, to guide attachment/detachment of the process cartridge to and from a cartridge mounting part formed on a main body frame of the image-forming apparatus. The first and the third guiding protuberances among the four guiding protuberances are formed on the first and the second plates, and the second and the fourth guiding protuberances are formed on both sides of the cartridge frame, respectively, and the first and the second through holes to receive the second and the fourth guiding protuberances in a passing through manner, are formed in the first and the second plates.

1. Field of the Invention
The present invention relates to an image-forming apparatus and more particularly to a process cartridge of an electrophotographic image-forming apparatus.
2. Description of the Related Art

As is well known, the electrophotographic image-forming apparatus carries out developing of an electrostatic latent image formed on a photoconductive medium by using toner and outputting the developed image, i.e., toner image by transferring the toner image on the photoconductive medium into a printing paper.
Such electrophotographic image-forming apparatus has a photoconductive medium, a light-exposing unit to form an electrostatic latent image on the photoconductive medium, a developing unit to develop an electrostatic latent image, a transferring unit to transfer the developed image onto a paper, a fixing unit to fix the transferred image on the paper, and a paper-feeding/discharging unit.
There are a variety of rollers required to constitute the photoconductive medium and the developing unit, and the rollers are degraded in performance over time, causing image degradation. Accordingly, these rollers require periodic replacement. Additionally, toner is a consumable and should be supplied in time when used up.
The process cartridge is designed to make the replacement process simple and convenient by incorporating elements such as a variety of rollers of the photoconductive medium and the developing unit and a predetermined amount of toners, all having similar lifespan, into one part as a cartridge.
FIG. 1 is a cross-sectional view of an inner structure of the general process cartridge, and FIGS. 2A and 2B are left side and right side perspective views, respectively.
Referring to FIG. 1, a reference numeral 10 refers to a cartridge frame. As shown in FIG. 1, the cartridge frame 10 has a toner reservoir 11 and a toner recovery part 12. The photoconductive medium 20 is positioned between the toner reservoir 11 and the toner recovery part 12 of the frame 10. The developing roller 31 is installed in the cartridge frame 10, maintaining a predetermined developing nip with respect to the photoconductive medium 20. The toner supplying roller 32 is installed in the cartridge frame 10 to supply toner to the developing roller 31. In FIG. 1, the reference numerals 33, 41, and 42 represent an agitator, a charging roller, and an auxiliary charging roller, respectively, and the reference numerals 43, and 44 represent a doctor blade and a cleaning blade, respectively.
As shown in FIGS. 2A and 2B, the process cartridge has first and second plates 50 and 51 joined on both sides of the cartridge frame 10, supporting both ends of the shafts of respective rollers installed in the cartridge frame 10, including the photoconductive medium 20, the developing roller 31, the toner supplying roller 32, the agitator 33, the charging roller 41, and the auxiliary charging roller 42.
First through fourth guiding protuberances 50a, 50b, 51a, and 51b are formed on the first and the second plates 50 and 51 to provide guidance during attachment/ detachment of the process cartridge to and from the image-forming apparatus. More particularly, the first and the third guiding protuberances 50a and 51a are formed in register with the photoconductive medium shaft 20a, and the second and the fourth guiding protuberances 50b and 51b are formed apart from the first and the third guiding protuberances 50a and 51a by a predetermined distance.
Referring to FIG. 3, a cartridge mounting part 61, on which the process cartridge is mounted, is provided to a main body frame 60 of the image-forming apparatus, and the cartridge mounting part 61 has a guide rail 61a, which is inclined a predetermined angle, and an seating part 61b, having a substantially semicircular shape.
With such a configuration, when the process cartridge is mounted on the main body frame 60 of the image-forming apparatus, the first through the fourth guiding protuberances 50a, 50b, 51a, and 51b, formed on the first and the second plates 50 and 51 of the process cartridge, enter by sliding on the guiding rail 61a. Then, as shown in FIG. 4, the first and the third guiding protuberances 50a and 51a settle down on the seating part 61b, whereby the photoconductive medium is normally grounded and mounted.
In dismounting the process cartridge from the main body frame 60 of the image-forming apparatus to replace the process cartridge, the process cartridge is drawn in the direction of the arrow in FIG. 5A, and accordingly, the first and the third guiding protuberances 50a and 51a are rotated in the direction of the arrow as shown in FIG. 5B with the second and the fourth guiding protuberances 50b and 51b acting as a hinge point, moving out of the seating part 61b of a semicircle shape, so that the process cartridge may be separated through the process as shown in FIG. 5C.
However, since, in the above-described general process cartridge of the image-forming apparatus, the first through the fourth guiding protuberances 50a, 50b, 51a, and 51b to guide attachment/detachment of the process cartridge, are integrally formed on the first and the second plates 50 and 51, which are joined to both sides of the cartridge frame 10, the following problems may be generated.
The first and the second plates 50 and 51 are assembled to the cartridge frame 10 by way of a screw fastening operation. Upon assembling of the first plate 51 (e.g., on the right side), a force C to rotate the plate 51 in the screw rotating direction, is generated as shown in FIG. 6A of the cartridge. Such rotational force C of the plate 51 pushes out the developing roller 31 to rotate in the clockwise direction with the seen direction used for the reference, while in contact with a side of the photoconductive medium 20. But, upon assembling of the second plate 50 (left side), as shown in FIG. 6B, since the developing roller 31 is rotated in the counterclockwise direction with the seen direction used for the reference, the rotational direction of the developing roller 31 is forced to rotate in a direction opposite to the screw rotating direction. Namely, a force D is generated, causing a rotation of the plate 50 toward the direction in which the developing roller 31 is separated from the photoconductive medium 20.
Such rotation of the first and the second plates 50 and 51 in the assembling process causes non-uniformity in right and left developing nips between the photoconductive medium 20 and the developing roller 31. This results in, irregular densities in right and left portions of an image and a difference in developing amounts at right and left sides. Accordingly, lifespans of right and left parts, including the roller in the cartridge, are different, and image output becomes irregular. In a serious case, the photoconductive medium 20 and the developing roller 31 partially disengage, causing the white-void on the image.
Also, the rotation of the plates 50 and 51 may generate deformation of the cartridge frame 10 and may cause aging of the photoconductive medium 20 and the roller 31, whereby serious image problem may result.
Also, in the conventional process cartridge, upon assembling, the plates 50 and 51 are assembled with a photoconductive medium shaft 20a used for the reference, but aligning all parts to be assembled using such one reference point is difficult.
Also, there is no way to check the error if the dimensions of the projecting portions of the plates 50 and 51, such as the distance between the first guiding protuberance 50a and the second guiding protuberance 50b or the distance between the third guiding protuberance 51a and the fourth guiding protuberance 51b are formed inaccurately during the manufacturing process, and the process cartridge may be incorrectly mounted on the main body frame of the image-forming apparatus.

Process cartridge for image forming apparatus


A bonding tool assembly (10) for supporting a composite part structure (11) during fabrication and curing processes, includes a bonding tool (12) and a plurality of fairing bars (14). The bonding tool (12) contains a support surface (16) upon which a composite part structure (11) is placed. The plurality of fairing bars (14) are placed completely around the periphery of the composite part structure (11) providing lateral support. The fairing bars (14) each contain a mating surface (18) which is placed directly upon the support surface (16) of the bonding tool (12). Each mating surface (18) contains a plurality of extended indexing protrusions (20) which form a distinct pattern and are secured by threaded fasteners (21). The support surface (16) contains a plurality of indexing recesses (22) that are configured to form the same pattern as the indexing protrusions (20) such that the fairing bars (14) and the bonding tool (12) are matable. Each fairing bar (14) also contains a plurality of magnets (24) that are located in pockets (26) slightly above the mating surface (18) of the fairing bars (14). The magnets (24) are secured in the pockets (26) by a heat-resistant adhesive (28). The fairing bars (14) magnetically adhere to the support surface (16) of the bonding tool (12) which is either adapted of a magnetically conductive material or contain magnetically conductive inserts (30).

The use of high strength fiber-reinforced composite material in the manufacture of aircraft and other lightweight structures has increased steadily since the introduction of such materials. Composite materials have a high strength to weight ratio and stiffness. These properties make composite materials attractive for use in the design of lightweight structures. One of the major drawbacks to using composite materials however, is the relatively high cost of production using these type of materials.
When a bonded composite assembly is fabricated it is "layed-up" in a bonding tool. Most composite assemblies consist of a skin (usually fiberglass, graphite, or aluminum) that sandwiches a core material that is also usually fiberglass, graphite, aluminum, or titanium. The core is generally hexagonal in shape although other core shapes can be implemented as well. There are several different variations of the composite assembly process in use, but all are eventually autoclave or oven cured in a bonding tool.
During the curing process a composite assembly is sealed inside a vacuum bag and then placed in an autoclave or oven, for curing at elevated pressures. To prevent damage to the composite assembly during the curing process, fairing bar are required to be used. The function of the fairing bars is two-fold: (1) to keep the vacuum bag from breaking due to bridging over voids or gaps along the edges, and (2) to prevent the composite core from being crushed in a "domino effect" due to the lateral forces from the pressurization. Composite materials are typically quite susceptible to collapse from lateral forces and thus need to be supported laterally in order to withstand the forces created by the elevated pressures of the curing process.
Fairing bars are typically positioned around the periphery of each composite assembly. Typically between 12 and 20 fairing bars are used per tool, although this number can vary widely depending upon the size and complexity of the composite assembly. The composite fabrication process requires that the fairing bars be removable. Thus, each fairing bar is configured to be bolted or otherwise hard fastened to the bonding tool, usually with a minimum of three bolts per fairing bar. Such bolts engage vacuum bushings inserted through the facesheet of the tool at each bolt location. Inserting such bushings typically requires that a computer controlled six axis mill be used to bore each hole, countersink the hole, and then backspotface the hole. After each hole is machined, an internally threaded vacuum bushing is inserted, sealed (usually with a silicone adhesive), and then checked for integrity.
The bonding tool is then released to production workers who bolt each fairing bar in place during the composite fabrication process. In order to hold each fairing bar in position bolts are used that are approximately 0.5 inches to 2.0 inches in length.
Prior to bolting the fairing bars in place, the bolts are coated using a releasing agent, such as Frekote.RTM.. This releasing agent is designed to prevent the composite resins, which flow freely in the composite assembly during curing, from permanently adhering the bolts to the fairing bars and the bonding tool and thus, the fairing bars to the bonding tool. Following each oven or autoclave cycle, these bolts are removed along with the fairing bars. At this stage bolts are often lost, requiring the acquisition of replacement bolts. In addition to the time required to obtain new bolts, further time is also required for each new bolt to be coated with a releasing agent.
For the manufacture of most parts, production workers must spend several hours locating bolts and securing the fairing bars to the bonding tool. This process is then subsequently repeated, since these fairing bars must be removed after every autoclave or oven cure cycle. In approximately 25% of any given run of composite parts, at least one of the bolts becomes bonded into the tool, thus locking the fairing bar to the bonding tool. This can require several further hours to remedy. Also, approximately 0.25% of all composite parts have to be scrapped due to loss of vacuum pressure during an autoclave cycle. This is directly attributable to vacuum bushings leaking, which occurs as a result of over torquing of the bushings and cracking of the bushings due to temperature and pressure cycling.
Previous attempts have been made to avoid the above mentioned problems and costly production time requirements. One such attempt to quicken the indexing and securing of fairing bars to a bonding tool, relied on "bullet nosed liners" to replace bolts. This technique basically mated short male pins with female bushing. This technique was unsuccessful however in that the pins had a tendency to fall out and/or break under heated, pressurized conditions. This pin/bushing method was also ineffective in holding a fairing bar to a vertical surface. Thus, a sound technique is still needed that can provide the benefits of securely bolting fairing bars to bonding tools without the inherent costly production time delays resulting therefrom.


A stabilizing fin that includes a hollow tubular element that has an upper surface for attachment to the bottom surface of a water planing device. The tubular element has an open front end and open rear end. During use thereof the hollow tubular element provides lateral stability and vertical stability while allowing for increased turning ability for enhanced control by a user. The water planing device may be, for example, a surfboard, a wind surfing board, a kite board, a water ski, a wake board or a boat.

1. Field of the Invention
The field of this invention relates generally to the field of fins for water craft and more particularly toward a fin or keel that stabilizes a surfboard or other water craft laterally, vertically. The primary purpose of the instant invention is the stabilization of a surfboard or other water craft where the intended craft direction, wave direction and hydraulic lift form a critical nexus of conditions which are to be controlled and maneuvered when operating the water craft.
2. Description of the Prior Art
There are many different types of stabilizing fins and keels or rudders on the market. The present invention seeks to offer greater control in a wider range of conditions than those currently found on the market. When maneuvering water planing devices it is beneficial to utilize a steering mechanism of some sort. Traditional methods of maneuvering and steering water craft typically involve a propulsion system and a steering system. The steering system benefits from physical engineering aspects, such as the manipulation and control of vertical lift and horizontal tracking combined with craft characteristics that effect aspects of control, such as buoyancy, rail or edge shape and bottom aspects like rocker, flat, concave or convex attributes.
Some water crafts achieve propulsion from a pull type propulsion force. Sail boarding, sailing, wakeboarding, water skiing, wind surfing and kite surfing are examples of this). Other water crafts utilize push type propulsion forces. Surfing and motor boating on waves are examples of this. Each type of propulsion system benefits from different combinations of craft and fin, or keel characteristics that work together to achieve the most desirable maneuverability. Craft speed and direction in relation to the propulsion direction combine with occupant weighting to the fore, or aft, left (starboard) and right (port) as well as relative pitch or angle on the water surface provide necessary inputs to optimal craft and occupant ride. The maneuverability of water craft depends on the direction of propulsion, the force of propulsion, the plane of the water surface, the pitch and direction of water craft, i.e., the edges, bottom profile, rocker and keel/rudder/fin.
The instant invention seeks as its primarily application for use on surfboards and high performance windsurfing boards. However, it is understood that it can be used on any water planing water craft or device. Persons who engage in floating and sliding water sports seek maximum control over their craft in a variety of conditions. Surfboards, of all of the common types of water craft, operate in the most dynamic and rigorous conditions. Accordingly, for illustration purposes, this application will be directed by way of example to the dynamics of steering a surfboard in the most critical of conditions, i.e., slow and mushy or hollow and fast waves. Nonetheless, the benefits described herein apply to different effect to all other water craft.
Three primary attributes that traditional steering mechanisms for water craft focus on are drag, stall and lift. Stall is a commonly used term in surfing and windsurfing where the rider of the water craft wishes to significantly alter the course of their water craft and a condition exists where there is not enough momentum and leverage to complete the desired course correction. Stall often ends the ride on the wave via the wave continuing on with the rider falling into the water, or otherwise impairs an ideal ride on the wave. Stall can also have other and very dangerous consequences for riders. Stall can be used to describe the situation where a water craft's momentum down the face of a wave is overcome by significant upward thrust of waves, called hydraulic lift. When the forward momentum is overcome by the force of the hydraulic lift and stall occurs, it can send the board reeling in the circular path of the dominant force of the wave as it crests and breaks. A rider in the path of a reeling board driven by the wave and the thousands of pounds per square inch that is possible when waves crash can be lethal. Minimizing board stall, accordingly, has many advantages to the rider.
The instant invention assists in steering and maneuvering water craft with increased effectiveness in both slow and mushy waves as well as in steep an fast ones. Various types of water craft in need of steering mechanisms can benefit from the device of the instant invention. Surfboard and wind surfboards benefit the most and so those types of water planing devices will be the focus of this disclosure. The benefits are realized, however, in many of the otherwise mentioned planing devices.
The ability of prior art mechanisms to overcome or minimize forces creating drag and stall are sufficient, but they miss out on potential benefits in many circumstances.
The problem with some prior art designs is the drag involved with the shaft, which is difficult to overcome. Bolen has several patents (U.S. Pat. Nos. 6,106,346, 6,379,204, 6,767,266, 6,217,402) utilizing a fin that has planar elements on top of and on the bottom of a cylindrical fin. These planar elements serve to increase drag and reduces lift. The instant invention removes the problematic elements of these inventions to provide for improved performance. U.S. Pat. No. 6,089,935 to Fleming III does not have a cylindrical mounting surface that is found in the instant design, i.e., there is no top to the fin. Fleming discloses a cylindrical bottom which is the point that actually adds drag. The instant invention contains the majority of the surface focused where the board meets the fin. U.S. Pat. No. 6,955,577 suffers from similar limitations found in Fleming. U.S. Pat. No. 3,103,673 to Martin has a planar element and uses a tilt that is downward at the fore and aft angles toward the ski. This creates significant drag and holds the ski down in the water. The instant invention operates to create lift and angles the cylinder in the opposite direction from Martin. U.S. Pat. No. 3,089,157 to May suffers from similar limitations described herein. The object of the instant invention is to provide a water planing device that reduces drag and increases lift, something that all of the prior art has failed to do.
To a large extent, the designs of steering mechanisms for water craft have not evolved much. Standard fin designs utilize a dorsal-type fin, which primarily works with the agency of propulsion referred to as drift. To understand, one can visualize a tuna swimming and using its tail fin for thrust or propulsion (back and forth motion). A tuna uses its dorsal and pectoral fins to control vertical and horizontal steering, while mainly using its tail for propulsion. Standard surfboard steering is achieved through a dorsal style fin or fins and vertically oriented tail fins. These surfboard fins offer very little in terms of positive effects on lift. Furthermore, their rigid straight line construction with its perpendicular orientation to the board actually is a hindrance to some aspects of performance. This hindrance appears in its effect on draft, stall and low-lift.
It is the object of the instant invention to provide an improved device to place on the bottom surface of water planing devices in order to overcome the shortcomings of the prior art. The instant invention provides lift and reduced stall by approximately mimicking cetaceans or dolphin and whale tails, or bat rays/manta rays, and bird wings; rather than shark, tuna, or dolphin tail/dorsal fin combinations.

Stabilizing fin for a water planing device


In general, techniques are described for providing feedback loops for service engineered paths. A service node comprising an interface and a control unit may implement the techniques. The interface receives traffic via a path configured within a network to direct the traffic from an ingress network device of the path to the service node. The control unit applies one or more services to the traffic received via the path and generates service-specific information related to the application of the one or more services to the traffic. The interface then sends the service-specific information to at least one network device configured to forward the traffic via the path so that the at least one network device configured to forward the traffic via the path is able to adapt the path based on the service-specific information.

Recently, network devices that form computer networks have been adapted to enable a form of networking referred to as "software-defined networking." In software-defined networking, the forwarding plane of a network switch, router or other network device is made available via a communication protocol such that this forwarding plane may be configured via the communication protocol rather than a routing protocol. In many implementations, the network devices may execute software to enable communications with other network devices in the network via this communication protocol so as to configure paths through the network. One example of a communication protocol that facilitates software-defined networking is the so-called "OpenFlow" communication protocol. OpenFlow is an open standard that allows users (e.g., researchers) to install software on the routers to run experimental or proprietary protocols to control packet routing or switching within a network.
The software controlled path setup may then orchestrate the configuration and deployment of paths on an as-needed basis to suit a particular service. To illustrate, orchestrating software that controls path setup may be manually configured with information identifying a network address translation (NAT) service operated by a first network device (service node). A second network device that does not provide a NAT service may communicate with the orchestrating software, learn of this NAT service and subscribe to this service, whereupon the orchestrating software may configure a path through the network from the second network device to the first network device. The second network device may then push traffic requiring NAT service through the path, where the first network device may apply the NAT traffic. When establishing the path, the orchestrating software may configure one or more filters on the second network device controlling admission of network traffic into the path. These paths having been engineered for a particular service, i.e., NAT service in this example, having filters controlling admission to the path may be referred to as "service engineered paths" (or "SEPs"). In this respect, the orchestrating software may define these SEPs to suit a particular service in terms of defining filters tailored for that service.
While SEPs may provide for service sharing and enable other network devices to forward traffic via a path that meets the needs of the service application (e.g., in terms of quality of service (QoS) provided, bandwidth, etc.), SEPs may not generally be responsive to changes in the service application. In other words, the control software managing the forwarding planes of the routers or switches along a SEP may be configured to accommodate network conditions through provisioning of paths that meet certain network requirements (e.g., in terms of bandwidth, quality of service, etc.), but may not be adapted to dynamically or automatically accommodate changes at service nodes.

Feedback loop for service engineered paths


A demodulation image sensor, such as used in time of flight (TOF) cameras, extracts all storage- and post-processing-related steps from the pixels to another array of storage and processing elements (proxels) on the chip. The pixel array has the task of photo-detection, first processing and intermediate storage to create subframes, while the array of storage and processing elements provides accumulation into frames. Particularly, sampled values of several subframes are summed in a compressed manner. Possible compression is to use exponential function.

Electronic imaging sensors usually have an array of m×n photo-sensitive pixels, with m>=1 rows and n>=1 columns. Each pixel of the array can individually be addressed by dedicated readout circuitry for column-wise and row-wise selection. Optionally a block for signal post-processing is integrated on the sensor.
The pixels typically have four basic functions: photo detection, signal processing, information storage, and analog or digital conversion. Each of these functions consumes a certain area on the chip.
A special group of smart pixels, called demodulation pixels, is well-known for the purpose of three dimensional (3D) time of flight (TOF) imaging. Other applications of such demodulation pixels include fluorescence life-time imaging (FLIM). The pixels of these demodulation imaging sensors typically demodulate the incoming light signal by means of synchronous sampling or correlating the signal. Hence, the signal processing function is substituted more specifically by a sampler or a correlator. The output of the sampling or correlation process is a number n of different charge packets or samples (A0, A1, A3 . . . An−1) for each pixel. Thus, n storage sites are used for the information storage. The typical pixel output in the analog domain is accomplished by standard source follower amplification. However, analog to digital converters could also be integrated at the pixel-level.
The image quality of demodulation sensors is defined by the per-pixel measurement uncertainty. Similar to standard 2D imaging sensors, a larger number of signal carriers improves the signal-to-noise ratio and thus the image quality. For 3D imaging sensors, more signal carriers mean lower distance uncertainty. In general, the distance measurement standard deviation a shows an inverse proportionality either to the signal A or to the square root of the signal, depending whether the photon shot noise is dominant or not.
  σ  ∝      1          A
if photon shot noise is dominant
  σ  ∝      1    A
it other noise sources are dominant
A common problem for all demodulation pixels used in demodulation sensors, such as for TOF imaging or FLIM, or otherwise, arises when trying to shrink the pixel size to realize arrays of higher pixel counts. Since the storage nodes require a certain area in the pixel in order to maintain adequate full well capacity and thus image quality, the pixel's fill factor suffers from the shrinking process associated with moving to these larger arrays. Thus, there is a trade-off between the storage area needed for obtaining a certain image quality and the pixel's photo-sensitivity expressed by the fill-factor parameter. In the case of a minimum achievable image quality, the minimum size of the pixel is given by the minimum size of the total storage area.
In 3D imaging, typically a few hundreds of thousands up to several million charge carriers, i.e. typically electrons, need to be stored in order to achieve centimeter down to millimeter resolution. This performance requirement, in turn, means that the storage nodes typically cover areas of some hundreds of square micrometers in the pixel. Consequently, pixel pitches of 10 micrometers or less become almost impossible without compromises in terms of distance resolution and accuracy.
The aforementioned trade-off problem becomes even more critical if additional post-processing logic is to be integrated on a per-pixel basis. Such post-processing could include for example analog-to-digital conversion, logic for a common signal subtraction, integrators, and differentiators, to list a few examples.
Another challenge of the demodulation pixels is the number of samples required to unambiguously derive the characteristics of the impinging electromagnetic wave. Using a sine-modulated carrier signal, the characteristics of the wave are its amplitude A, the offset B and the phase P. Hence, in this case, at least three samples need to be acquired per period. However, for design and stability reasons, most common systems use four samples. Implementing a pixel capable of capturing and storing n=4 samples requires in general the four-fold duplication of electronics per pixel such as storage and readout electronics. The result is the further increase in the electronics per pixel and a further reduction in fill factor.
In order to avoid this loss in sensitivity, most common approaches use so-called 2-tap pixels, which are demodulation pixels able to sample and store two samples within the same period. Such type of pixel architectures are ideal in terms of sensitivity, since all the photo-electrons are converted into a signal and no light is wasted, but on the other hand, it requires at least two consequent measurements to get the four samples. Due to sampling mismatches and other non-idealities, even four images might be required to cancel or at least to reduce pixel mismatches. Such an approach has been presented by Lustenberger, Oggier, Becker, and Lamesch, in U.S. Pat. No. 7,462,808, entitled Method and device for redundant distance measurement and mismatch cancellation in phase measurement systems, which is incorporated herein by this reference in its entirety. Having now several images taken and combined to deduce one depth image, motion in the scene or a moving camera renders artifacts in the measured depth map. The more those different samples are separated in time, the worse the motion artifacts are.
A new architecture has been disclosed by Oggier and Buettgen in U.S. Pat. Pub. No. 2011/0164132A1. The architecture enables the shrinking of the pixel size without significantly reducing the pixel's fill factor and without compromising the image quality due to smaller storage nodes. The solution even provides the possibility for almost arbitrary integration of any additional post-processing circuitry for each pixel's signals individually. Furthermore, it can reduce the motion artifacts of time-of-flight cameras to a minimum. Specifically, this demodulation sensor comprises a pixel array comprising pixels that each produce at least two samples and a storage or proxel array comprising processing and/or storage elements, each of the storage elements receiving the at least two samples from a corresponding one of the pixels. The pixels comprise photosensitive regions in which incoming light generates charge carriers and demodulators/correlators that transfer the charge carriers among multiple storage sites in the pixels. A transfer system is provided that transfers the samples generated by the pixels to the corresponding storage elements of the proxel array. In example embodiments, the transfer system analog to digitally converts the samples received by the storage elements. The proxel array then accumulates multiple subframes in time until the entire frame is readout from the proxel array.

Time of flight sensor with subframe compression and method


A 5 GHz wireless stereo sound system having a transmitter and a receiver; the transmitter and the receiver are wirelessly connected via a 5 GHz signal. The 5 GHz wireless stereo sound system wirelessly transmits on a 5.2/5.8 GHz frequency in 24-bit/48K digital only, thereby avoiding interference from wireless devices that transmit on 2.4 GHz frequency band (including Bluetooth and personal area networks), infrared devices and so forth, thus solving the problems of mutual interference between conventional wireless devices and instability of signal transmission, thereby ensuring transmission stability.

The present invention belongs to the field of sound and more particularly pertains to a 5 GHz wireless stereo sound system.
Existing wireless audio technology usually involves two types, namely analog and digital audio. Wireless analog audio comprises FM (frequency modulation), AM (amplitude modulation), infrared and so forth. Analog audio signals are commonly susceptible to the problems of interference and instability. Wireless digital audio comprises Bluetooth, Wifi, Apple's AirPlay, Android DLNA and so forth, which belongs to the field of 2.4 GHz wireless audio technology.
2.4 GHz wireless audio technology solves the problems such as cabling difficulty and time-consuming issues, reduces installation and maintenance costs, and has wide application range, high bandwidth and low power consumption. However, due to a massive selection of 2.4 GHz (2.4-2.484 GHz) ISM band, the electromagnetic compatibility problem of this band is serious. Signals interfere with each other, resulting in pause or intermittence in wireless audio transmission.
In addition, most existing wireless audio systems adopt an integrated design which integrate wireless receiving, decoding and power amplification in speaker. Although the integration of the audio system simplifies the configuration of the audio system, it is impossible to select combination of components since all parts are integrated; it is also not possible to combine and form new desired systems.


A method for photographic processing of an exposed photosensitive film wherein a plurality of photographic processing elements comprising a carrier layer and a photographic processing layer containing photographic processing material are brought into contact, consecutively, with the exposed photosensitive film whereby a visible image is formed in the film. Each photographic processing element is initially brought into contact with the photosensitive film with the application of pressure and the processing element and the film are allowed to remain in contact with each other for a required period of time, during which at least one, and preferably a plurality of, additional pressure applications are carried out.

The invention is directed generally to a photographic processing method wherein an image is formed in an exposed photosensitive film and, more particularly, to such a method which utilizes photographic processing elements comprising a carrier layer and a photographic processing layer containing photographic processing materials.
Generally, it is known in the art to carry out photographic processing of an exposed photosensitive film with photographic processing elements which comprise a carrier layer and a photographic processing layer which contains photographic processing materials. U.S. Pat. No. 2,558,857 to Land teaches bringing a sheet material having a viscous coating comprising a liquid composition including a developer and a silver halide solvent into contact with an exposed photosensitive layer to develop a latent image in the photosensitive layer and thereby form a visible image. A photographic processing method of this type is generally referred to in the art as "dry" since the photographic processing chemicals are included in a layer of the photographic processing element and the photographic processing elements take the place of the photographic processing solution baths utilized in conventional "wet" photographic processing methods.
The prior art also describes materials which may be used in the dry photographic processing techniques. U.S. Pat. No. 3,615,482 to Cronig teaches gelable photoprocessing solutions which comprise a photoprocessing solution and an amount of gel-forming carrageenan or furcellaran sufficient to cause gelation of the solutions. The gelled compositions are taught as being useful to develop, bleach, fix, wash, etc. exposed photographic films. U.S. Pat. No. 3,680,462 to Cronig teaches a photographic processing apparatus which utilizes gelled photographic processing compositions.
Variations of photographic processing using dry photographic processing elements have been described in the art. In one technique a single processing element is brought into contact with the photosensitive film to carry out photographic development. U.S. Pat. No. 5,440,366 to Reiss and Cocco teaches a photographic processing system and method wherein individual dry photographic processing elements are sequentially wrapped onto a single processing spool. One embodiment utilizes a processing spool which houses all the photosensitive processing sections carried on a single carrier layer such as, for example, a first processing section which contains a photographic developer, a second processing section which contains bleaching and fixing chemicals and a third processing section which contains washing and stabilizing chemicals. An exposed photosensitive film, which is housed in a separate cartridge is extracted from the cartridge and the first processing section is brought into contact with the film for a predetermined period of time following which the first processing section is separated from the film and the second processing section is brought into contact with the film for a requisite period of time. Subsequently, the second processing section and the film are separated from each other and the third processing section is brought into contact with the film for a requisite period of time. After the third processing section and the film are separated from each other the photographic processing is complete and a visible image is formed in the film.
While there has been interest in carrying out photographic processing of exposed photosensitive film with dry processing elements, the systems and methods described in the prior art have not been entirely satisfactory insofar as providing the desired results. Accordingly, there is a continuing need for novel and improved systems and methods for forming images in exposed photosensitive films using dry photographic processing materials.
It is therefore an object of this invention to provide a novel photographic processing method.
It is another object to provide a photographic processing method wherein an exposed photosensitive film is processed with a plurality of dry photographic processing elements.
It is a further object of the invention to provide a photographic processing method wherein an exposed photosensitive film is processed with a plurality of separate dry photographic processing elements.


A method for phase-contrast magnetic resonance imaging (PC-MRI) acquires undersampled PC-MRI data using a magnetic resonance imaging scanner and reconstructs MRI images from the undersampled PC-MRI data by reconstructing a first flow-encoded image using a first convolutional neural network, reconstructing a complex difference image using a second convolutional neural network, combining the complex difference image and the first flow-encoded image to obtain a second flow-encoded image, and generating a velocity encoded image from the first flow-encoded image and second flow-encoded image using phase difference processing.

Phase Contrast Magnetic Resonance Imaging (PC-MRI) is widely considered the clinical gold-standard for non-invasive and time-resolved visualization and quantification of blood velocity (cm/s) and flow (mL) throughout the cardiovascular system. Clinically, PC-MRI is used to aid in the diagnosis and treatment of cardiovascular disease, including valvular stenosis (velocity) as well as regurgitation, right/left lung flow splits, and shunts (flow). However, one of the main challenges associated with the technique is the need to minimize the breath hold duration while accommodating the spatiotemporal requirements for accurate and precise measurements of blood velocity and flow.
PC-MRI uses encoding gradients to map the velocity of flowing blood to the phase of the measured complex MR signal. This method requires the acquisition of at least two images with appropriate flow encoding, such that the phase difference of the two flow encoded images eliminates intravoxel off-resonance effects due to magnetic field inhomogeneity. Furthermore, to mitigate artifacts associated with cardiac and respiratory motion, cardiac ECG triggering is used to acquire data over several heartbeats. This acquisition scheme requires patients to hold their breath for upwards of 20 seconds, which oftentimes can be difficult. Also, conventional PC-MRI requires the scan operator to balance scan duration, artifact mitigation, spatial resolution, temporal resolution, and signal-to-noise ratio (SNR). This balancing act limits the accuracy, precision, and repeatability of the technique.
A wide variety of methods have been proposed to reduce PC-MRI scan times, including non-Cartesian sampling strategies, Parallel Imaging (PI) undersampling, Compressed Sensing (CS), and Low-Rank (LR) matrix recovery. CS is one of the most successful techniques, to date, to decrease PC-MRI scan times by reducing the number of acquired k-space samples via a pseudorandom undersampling scheme. These schemes produce noise-like artifacts that are later removed with iterative reconstruction algorithms that alternately enforce data consistency and denoise based on prior sparse modeling. Specifically for PC-MRI, several studies have exploited the spatiotemporal redundancy of dynamic cardiac images. Nevertheless, the generic assumptions of CS are often unable to accurately describe the complexity of cardiac dynamics, limiting the achievable acceleration and/or reducing the accuracy and precision of clinically important quantitative measures. More recent work has extended the CS sparse representation model to PC-MRI data by directly reconstructing Complex Difference (CD) images rather than traditional phase difference images. CD images are considerably more sparse and could potentially result in increased accuracy and precision at higher acceleration factors.

Artificial intelligence based reconstruction for phase contrast magnetic resonance imaging

The Board of Trustees of the Leland Stanford Junior University

The United States of America as represented by The Department Of Veterans Affairs


A power amplifier includes a baseband modulator configured to receive a baseband amplitude component and generate a baseband modulated pulse string, an oscillator configured to receive a baseband phase component and generate phase modulated complex carrier signals, a complex up-converter configured to receive and mix the baseband modulated pulse string with the phase modulated complex carrier signals into mixed product signals, and two or more switched mode power amplifiers coupled to the complex up-converter, configured to amplify and switch the mixed product signals at the carrier frequency. The power amplifier further comprises complex filters individually coupled to one of the switch mode power amplifiers, configured to suppress image components in the amplified and switched mixed product signals, and a power combiner coupled to the two or more complex filters, configured to combine the real component of the complex filtered and amplified mixed product signals to generate an RF transmission signal.

Bandwidth-efficient modulation methods with a non-constant envelope are used in base stations of the third and higher generations. It is precisely this fluctuation that leads to the need to operate "quasi-linear" high-frequency power amplifiers with a large back-off operating point in order to meet the high linearity requirements that are usually specified by a standard. Utilizing this operating mode, however, leads to poor efficiency, which is reflected strongly in the production and operation costs of the base station.
There are a number of measures that can be used to improve efficiency under a given set of linearity requirements. This can be achieved by special HF power amplifier architectures, using improved transistor technologies, and by special linearization circuits (which can be realized both in the high-frequency range and in the digital baseband). The overall efficiency, which can be achieved by these state-of-the-art methods, however, is still only about 30%. Accordingly, there is a continued need to improve the efficiency of base station power amplifier and modulation systems.

Modulation system and method for switched amplifiers


A steering wheel/steering shaft assembly (10) comprising: a steering shaft (50) including a shaft portion having a first end (62), the first end including a first securing and aligning mechanism (52) which cooperates with a second securing and aligning mechanism (40) in the steering wheel (13) which clamps upon the first securing and aligning mechanism to orient the steering wheel at a preferred orientation to the shaft and lock same in place.

The present invention generally relates to steering wheels and steering shafts, and more particularly to an apparatus and method by which the steering wheel is attached to the steering shaft.
The typical steering wheel includes a rim and spokes which extend between a hub and the rim. The hub includes a splined bore which is press fit upon complementary splines formed at the end of the steering shaft. The end of the steering shaft is also threaded. After the steering wheel is properly aligned to the steering shaft it is pushed onto the end of the shaft with the end passing through the hub. A nut is screwed upon the splined/threaded end of the steering shaft. The above mounting procedure is possible since the upper side of the hub is accessible. Thereafter an air bag module, typically comprising a housing, inflator, air bag and cover, is secured to the upper side of the hub covering the nut. Other steering wheel/steering shaft attachment methods include inserting a threaded bolt into a threaded bore in the steering shaft with a key provided in the shaft and steering wheel to achieve proper alignment.
It has been proposed to replace the conventional steering wheel with an integrated steering wheel. The integrated steering wheel comprises an armature or metal core covered by a styled molded layer which covers the wheel spokes and wheel rim and also forms an air bag module cover. The air bag and air bag inflator are integrated within the steering wheel and situated between the integrally formed cover and the hub. The integrated steering wheel may also include a conventional steering wheel and a conventional air bag module comprising an air bag, inflator and cover. The steering wheel is attached to the steering shaft before the air bag module is secured to the hub of the steering wheel. Thereafter this integrated assembly is attached to the end of the steering shaft. As can be appreciated, it is no longer possible to attach the steering wheel to the steering shaft as described above, since access to the end of the steering (which extends into and through the hub) is now precluded. Consequently, new methodologies of attaching this integrated steering wheel/air bag assembly must be defined.
Since access to the front side of the steering wheel would no longer be available any attachment device will be located on the rear (or bottom) of the hub of the steering wheel. As can also be appreciated, with this attachment device located on the bottom of the hub, the assembly of the steering wheel to the steering shaft is a "blind" operation. As such, the assembly techniques must accommodate this type of operation.
In the assembly of any mating parts, there will be rotational and linear tolerances associated with both parts. It is an object of the present invention to provide an attachment system which accounts for these various tolerances.
It is a further object of the present invention to provide a clamping or gripping type of mechanism to connect the steering wheel and steering shaft.
The present invention comprises a specially shaped steering column and a gripping mechanism located on the back of a steering wheel. The top of the steering shaft contains a rectangular shaped section with a groove located in its center (or alternatively two spaced rectangular sections can be used to defined the groove). Positioned immediately below the rectangular section(s), about the shaft, is a circumferential groove. The gripping mechanism includes a first gripping (or clamping) part which is fixed to the lower side of the steering wheel hub and a slidably mounted second gripping (or clamping) part connected to the first gripping part by a threaded bolt. As will be seen below "gripping" and clamping" are used interchangeably. Each gripping part contains a flat surface which aligns with a corresponding flat side of the rectangular section of the steering shaft as the two clamping parts are moved together. This clamping action simultaneously causes the alignment of the steering wheel to a preferred orientation relative to the steering shaft. The two opposing gripping parts also mate with the circular groove, in the steering shaft, in such a manner as to remove tolerances up and down the shaft. This interconnection axially secures the steering wheel to the steering shaft.
Accordingly, the present invention comprises: a steering wheel/steering shaft assembly comprising: a steering shaft including a shaft portion having a first end, the first end including a first means for aligning and securing a steering wheel thereto. The steering wheel includes a second means, cooperating with the first means, for providing a clamp upon the steering shaft and in cooperation with the first means for causing the self-aligning of the steering wheel to a preferred orientation relative to the steering shaft. More particularly, the steering shaft includes a v-groove and a rectangular projection at its top. The second means includes two relatively movable gripping members, one of which is attached to the bottom of the steering wheel hub, which when in a clamping configuration positions a wedge within the v-groove to positively secure the wheel to the shaft and which engages the rectangular projection to align the steering wheel to a precise orientation relative to the steering shaft and to the passenger compartment.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.

Steering wheel assembly and method of use


The present invention relates to integral skin-foam molded articles obtained by reaction-injection molding a polyurethane foam material comprising a polyol component, an isocyanate component, a catalyst, and a blowing agent. Catalysts may be selected from tin and amine compounds. Water has been successfully used as a blowing agent.

Fluorocarbon-type blowing agents which enable the easy formation of integral skin (IS) layers, especially chlorofluorocarbons (CFCs) represented by trichlorofluoromethane (Freon-11), are frequently employed as the blowing agents in conventional urethane foam molding materials for producing urethane steering wheels (ISF molded articles) because CFCs meet the requirements for blowing agents enabling easy formation of IS layers (i.e., having moderate boiling points (-40.degree. to 70.degree. C.) and being easily liquified by slight pressurizing) and are free from the fear of fire or explosion, non-toxic, and inexpensive. However, since fluorocarbons, particularly CFCs, are thought to be a cause of the destruction of the ozone layer, there is an international trend toward control of the use of these components. Hydrofluorocarbons (HCFCs), for this reason, are attracting attention because it is thought they are less apt to destroy the ozone layer. However, substitution of HCFCs is not the ultimate solution because the compounds are not thought to completely eliminate the fear of ozone layer destruction.
On the other hand, molded articles produced from PUR foam materials of so-called water-blown formulations in which water is employed as the blowing agent have been marketed. However, the water-blown formulations have conventionally been thought to be unsuited for the production of ISF molded articles because it has been difficult to form a uniform IS layer using such formulation. Illustratively stated, the water-blown formulation practiced by one skilled in the art, foaming is based on carbon dioxide gas generated by the reaction of an isocyanate with water and this carbon dioxide gas is less apt to liquify at ordinary mold temperatures. Even with pressurization, the carbon dioxide gas generated in the foaming system, in a mold, does not liquify nor does it liquify on the outer part of the mold, where temperatures are lower. As a result, an IS layer is hardly formed.


Disclosed is a method for producing a homogeneous polycarbonate composition, which comprises feeding a first polycarbonate in a molten state to a first inlet of an extruder, while feeding a mixture of an second polycarbonate and at least one thermal stabilizer to a second inlet of the extruder, wherein the second inlet is disposed downstream of the first inlet, and extruding the first polycarbonate and the mixture through the extruder. By the method of the present invention, additives can be uniformly dispersed in a molten polycarbonate without dissolving the additives in a solvent, and a polycarbonate composition of the polycarbonate and the additive, which has various excellent properties, such as excellent thermal stability, can be produced efficiently.

1. Field of the Invention
The present invention relates to a method for producing a homogeneous polycarbonate composition. More particularly, the present invention is concerned with a method for producing a homogeneous polycarbonate composition of a polycarbonate and an additive, which comprises feeding a main polycarbonate in a molten state to a first inlet of an extruder, while feeding a resin/additive mixture of an auxiliary polycarbonate and at least one additive to a second inlet of the extruder, wherein the second inlet is disposed downstream of the first inlet, and extruding the main polycarbonate and the resin/additive mixture through the extruder. By the method of the present invention, additives can be uniformly dispersed in a molten polycarbonate, so that a polycarbonate composition having various excellent properties can be produced efficiently. For example, when a thermal stabilizer is added to and mixed with a molten polycarbonate by the method of the present invention, a polycarbonate composition having excellent thermal stability can be produced efficiently.
2. Prior Art
In recent years, polycarbonates have been widely used in various fields as engineering plastics which have excellent heat resistance, impact resistance and transparency. Various studies have been made with respect to processes for producing polycarbonates. Up to now, processes, such as one utilizing interfacial condensation polymerization of an aromatic dihydroxy compound, such as 2,2-bis(4-hydroxyphenyl)propane (hereinafter, frequently referred to as "bisphenol A"), with phosgene (hereinafter, frequently referred to as the "phosgene process"), have been commercially practiced. In the phosgene process, a mixed solvent of water or an aqueous alkali solution and a water-immiscible organic solvent are generally used (a mixed solvent of an aqueous sodium hydroxide solution and methylene chloride is practically employed as the mixed solvent); a tertiary amine or a quanternary ammonium compound is employed as a catalyst; and chlorine-containing by-products, such as hydrogen chloride are formed, and for example, hydrogen chloride is removed as a salt thereof with a base.
However, in the phosgene process, (1) toxic phosgene must be used; (2) due to the by-produced chlorine-containing compounds, such as hydrogen chloride and sodium chloride, an apparatus used is likely to be corroded; (3) it is difficult to remove impurities, which adversely influence the properties of the desired polycarbonate, such as sodium chloride, from the polymer; and (4) since methylene chloride (which is generally used as a reaction solvent) is a good solvent for polycarbonate and has a strong affinity to polycarbonate, the methylene chloride inevitably remains in produced polycarbonate. With respect to the remaining methylene chloride, removal thereof is extremely costly, and complete removal of the remaining methylene chloride from the obtained polycarbonate is almost impossible. Further, it is noted that the methylene chloride remaining in the polymer is likely to be decomposed, e.g., by heat at the time of molding the polymer, thereby forming hydrogen chloride, which not only causes corrosion of a molding machine but also lowers the quality of a molded product.
As mentioned above, the phosgene process involves too many problems, so that it has been desired to develop a process for producing a polycarbonate, which is free from difficulties inevitably accompanying the phosgene process.
Recently, a large number of researches and developments have been made with respect to a transesterification process for producing a polycarbonate from an aromatic dihydroxy compound and a carbonic diester, especially a melt transesterification process, which is attracting attention as a substitute for the phosgene process.
It is known that the melt transesterification process is advantageous in that a polycarbonate is obtained in a molten state at the time of completion of the polymerization reaction. For example, a polycarbonate obtained in a molten state can be directly subjected to pelletization and, hence, production of polycarbonate pellets can be conducted efficiently [see "Plastic Zairyo Koza 5, Polycarbonate Jushi (Lecture on Plastic Materials 5, Polycarbonate Resin)", p.62-67, published from The Nikkan Kogyo Shimbun Ltd. (The Daily Industrial News), Japan, 1969]. When it is desired to incorporate an additive into a polycarbonate in pellet form, it is necessary to mix polycarbonate pellets with an additive and melt the resultant mixture so as for the molten mixture to be melt-kneaded in an extruder. This operation is troublesome and economically disadvantageous. Therefore, it has been attempted to produce a polycarbonate/additive composition before a polycarbonate obtained in a molten form by a melt transesterification process is fabricated into pellets.
With respect to the method for producing a polycarbonate/additive composition obtained in a molten form by a melt transesterification process, wherein the additive, for example, a thermal stabilizer is incorporated, there can be mentioned Unexamined Japanese Patent Application Laid-Open Specification (Kokai) No. 5-310906 (corresponding to EP Publication 559953 and U.S. Pat. Nos. 5,278,279, 5,387,628 and 5,391,690) and Examined Japanese Patent Application Publication (Kokoku) No. 5-46843, which disclose a method for adding a phosphorus-containing thermal stabilizer to a polycarbonate obtained in a molten form by a melt transesterification process, wherein the thermal stabilizer is added during the melt polymerization reaction. Further, another method for mixing a polycarbonate obtained by a melt transesterification process with additives is disclosed in Unexamined Japanese Patent Application Laid-Open Specification (Kokai) No. 4-103626, wherein a thermal stabilizer is added to a polycarbonate in a molten state immediately after completion of the melt polymerization reaction.
However, the method disclosed in Japanese Kokai No. 5-310906 and Japanese Kokoku No. 5-46843 has problems in that a lowering of the polymerization rate occurs due to the presence of the thermal stabilizer, and that the polycarbonate composition containing the polycarbonate and the thermal stabilizer suffers discoloration because decomposition and other undesired reactions of the thermal stabilizer occur during the polymerization reaction. On the other hand, the method disclosed in Japanese Kokai No. 4-103626, in which a thermal stabilizer is added after completion of the polymerization reaction, would be free from the above-mentioned problems accompanying the techniques disclosed in Japanese Kokai No. 5-310906 and Japanese Kokoku No. 5-46843. However, this prior art document only describes that a thermal stabilizer and a polycarbonate are kneaded using a twin-screw extruder, but contains no description as to how to add the thermal stabilizer to the polycarbonate and achieve intimate blending of the former with the latter.
On the other hand, with respect to a polycarbonate obtained in the phosgene process (wherein the polycarbonate is obtained in powder or slurry form), it is relatively easy to blend the polycarbonate with an additive, such as a thermal stabilizer, uniformly and obtain a homogeneous composition. Illustratively stated, in the case of a phosgene-process polycarbonate in powder or slurry form, first, a thermal stabilizer which is either dissolved in a solvent, such as methylene chloride, or not dissolved, is added to the polycarbonate; second, the polycarbonate and the thermal stabilizer are then mixed well in a batchwise manner by using, for example, a Henschel mixer, to thereby obtain a mixture; and, third, the obtained mixture is subjected to melt extrusion, thereby obtaining a homogeneous polycarbonate/thermal stabilizer composition. Thus, with respect to a polycarbonate obtained by the phosgene process, it is possible to obtain a homogeneous polycarbonate composition comprising the polycarbonate and an additive (e.g., thermal stabilizer), even when the additive is used in a very small amount. However, as mentioned above, the phosgene process involves too many problems.
As mentioned above, with respect to a polycarbonate obtained in a molten state by a melt transesterification process, it is very difficult to uniformly blend a molten polycarbonate with a small amount of an additive.
Generally, in formulation of a composition of a polycarbonate and an additive, such as a thermal stabilizer, the additive is added in an extremely small amount, specifically in an amount as small as 0.0001 to 0.1 part by weight, relative to 100 parts by weight of the polycarbonate. Therefore, in producing polycarbonate compositions from polycarbonates in molten form and additives, such as a thermal stabilizer, the following various difficulties are encountered.
When a thermal stabilizer in a solid state at room temperature is added to a polycarbonate in a molten state, the thermal stabilizer is heat-melted in a feeder having a pump and fed to an extruder by using the pump, and in the extruder, the thermal stabilizer is mixed with a molten polycarbonate. When a thermal stabilizer is heat-melted in a feeder, the thermal stabilizer is inevitably kept in a molten state for a relatively long period of time, so that the thermal stabilizer deteriorates by heat to suffer discoloration and, hence, the resultant polycarbonate composition, containing such a discolored thermal stabilizer, also suffers from discoloration. On the other hand, when a thermal stabilizer which is in a liquid state at room temperature is added to a polycarbonate, the thermal stabilizer is fed to an extruder by using a feeder having a pump, and in the extruder, the thermal stabilizer is mixed with a molten polycarbonate. In this case, there is a problem such that when the thermal stabilizer is used in a very small amount, the thermal stabilizer cannot be dispersed uniformly, so that when the obtained polycarbonate composition is subjected to molding (in which the composition is heat-melted), the polycarbonate composition suffers discoloration because of its non-homogeneity. On the other hand, a method has been proposed in which a thermal stabilizer which is either in a solid state or in a liquid state at room temperature is dissolved in a solvent, such as methylene chloride, so as to increase its volume, and is fed to a liquid inlet of an extruder. By this method, a thermal stabilizer is well dispersed in a polycarbonate. However, the solvent used for dissolving the thermal stabilizer remains in the obtained polycarbonate composition in an amount as large as several tens to several thousands ppm. A polycarbonate composition containing such a large amount of solvent has poor thermal stability, so that not only is the composition likely to suffer discoloration at the time of molding, but a molded article is also likely to suffer discoloration when it is used under high temperature conditions.
Further, when a thermal stabilizer in powder or granular form, as such, is fed to an auxiliary inlet of an extruder (which auxiliary inlet is provided separately form a main inlet for a polycarbonate and is originally intended for use in feeding such a type of additive as used in a relatively large amount, e.g. a filler, a glass fiber or a carbon fiber), the feeding rate of the thermal stabilizer cannot be controlled precisely at a predetermined level because the amount of the thermal stabilizer to be fed to the extruder per unit time is so small that it is extremely difficult to feed the thermal stabilizer precisely to an extruder by means of a feeder thereof. Therefore, the thermal stabilizer cannot be dispersed uniformly in a polycarbonate, so that the thermal stability of the obtained polycarbonate composition is poor and, hence, not only does the composition suffer discoloration at the time of molding, but a molded article is also likely to suffer discoloration when it is used under high temperature conditions. Further, no feeder is available which can be suitably used for feeding a thermal stabilizer in a very small amount.
As mentioned above, it is very difficult to uniformly disperse a small amount of an additive in a molten polycarbonate obtained by the melt transesterification process, especially when the additive is used in a very small amount. When the additive is dissolved in a solvent and mixed with the polycarbonate, the additive can be well dispersed in the polycarbonate. However, as mentioned above, when a thermal stabilizer is dissolved in a solvent and mixed with the polycarbonate, the solvent remains in the resultant polycarbonate composition, so that the composition has poor thermal stability. Thus, it has conventionally been impossible to uniformly disperse a small amount of an additive in a molten polycarbonate obtained by a transesterification process, so that a polycarbonate composition having various excellent properties, such as excellent thermal stability has not been obtained.

Method for producing a homogeneous polycarbonate composition


A reel handler including at least one reel arm for engaging a reel is mounted on a frame. A moving device moves the reel arm to raise and lower the engaged reel, and a hydraulic motor for rotating the reel is contained within the end of the reel arm. The hydraulic motor includes a crank shaft operable to rotate the reel when the crank shaft is rotated. Preferably, two spaced reel arms are pivotally mounted on a transverse, telescoping support cylinder that allows the reel arms to be spaced at varying distances to accommodate reels of various sizes. At least two cylinder and piston assemblies are attached to the crank shaft for rotation of the crank shaft upon movement of each piston between a minimum and maximum point of travel in the cylinders. The two cylinders are offset with respect to each other such that each piston reaches its said minimum and maximum points of travel while the other is offset from its own said minimum point of travel. A valve assembly, driven by the crank shaft, provides hydraulic fluid to the cylinders under pressure to sequentially move each piston between its said minimum and maximum points of travel by providing hydraulic fluid under pressure on each piston in the desired direction of piston travel while evacuating hydraulic fluid under lesser pressure from the other side of the piston in its cylinder.

Motors that are driven by fluid pressure are not new. Steam engines utilize the expansion of pressurized steam in a cylinder to drive the piston, thereby deriving work energy from the expansion step. Internal combustion engines derive work energy from combustion of fuels in oxygen from the air to drive a piston in a cylinder. In both of these types of motors, the cylinder is subjected to rapid expansion of gasses that push the piston through one step in the power cycle. Depending on the particular type of motor, such as steam, two or four cycle internal combustion or diesel combustion, products are produced that are expelled via exhaust valves and the like.
Hydraulic motors are also used in some instances, where a fluid under pressure is introduced into a cylinder to drive a piston and thus convert hydrostatic energy to movement, usually rotational, by driving a crank shaft and the like. In some cases the hydraulic motor is designed to drive a shaft, usually in combination with a transmission or at gear box.
One form of hydraulic motor that has found use in industry is the low speed/high torque hydraulic motor. These motors have been found to have substantial advantages over systems in which a high speed motor is used in combination with a gear box speed reducer. A significant advantage is that the combination of low speed and high torque provides a large amount of power in a relatively small drive package. Other benefits include low noise and vibration, as well as high energy efficiency. Such low speed and high torque motors are capable of rapid reversal of direction by reversing the direction of hydraulic fluid flow.
These low speed and high torque hydraulic motors come in two basic forms and in a variety of designs. The motors either are gear reduction motors or radial piston motors. In the former, high speed motors are reduced using a complicated series of gears to lower the speed and achieve higher torque. In the latter, various schemes for moving fluids around the axis of a crankshaft have been provided.
Vane motors employ pressure against a plurality of vanes riding on a ring cam to form sealed chambers that carry fluid through the device, optimally at low pressure. The major disadvantage is that there are too many leakage paths. Rolling-vane motors sequence fluid flow to put high pressure against trailing surfaces and low pressure against leading surfaces, but are limited in displacement.
There are also a variety of piston motors. Radial piston motors have a wide displacement range and are very efficient in medium or high displacement ranges. Cam type radial piston motors are less efficient and have difficulty at low speed. Axial piston motors are effective and have good starting torque characteristics. Two sources of heavy duty hydraulic motors are Nutron Motor Co., Inc. in Eliot, Maine, which produces a radial piston hydraulic motor under the MHA series, and Kawasaki Precision Machinery, Inc. which produces radial piston hydraulic motors at its Staffa facility in Plymouth, England.
One of the principle drawbacks to hydraulic motors is that the commercial designs are extremely large for the power that is produced. Both the space or volume taken up by such motors and the weight that is needed are so great as to be seen as drawbacks or handicaps when selection of a motor is being made. In order to have useful torque in industrial applications, such as in heavy equipment, moveable boat and lumber lifts, end loaders, reel drives, winches, and other hub drive designs, great amounts of power is needed. However, all presently known designs are not capable of effectively using the power of a short stroke, high displacement motor arranged within a compact area or motor volume so as to be adapted to the device of interest.
It would be of great advantage if an improved hydraulic motor could be provided that would deliver the same or greater power using less space and having less weight than conventional motors which have been described.
In addition, it would be an advance in the art if high torque, low speed motors could be designed that did not require the use of multiple reducing gears to translate high speed motion into low speed, high torque output.
Further, it would be an advance in the art if a hydraulic motor could be provided that was capable of reversing virtually instantaneously to reverse the movement of any power transmission shaft to which the motor would be attached.
It would be a significant advance if a hydraulic motor could be provided that had the capability of self braking, so that no additional brake device would be needed for the motor, and the equipment to which it is attached, to remain motionless while supporting the full weight of the load being driven. In other words, it would be a great advance if the motor could stop at any pre-selected point and support the load attached thereto without the use of additional brake elements.
Reel handlers for loading and unloading reels from trucks or trailers are not new per se. Some reel handlers allow for powered payout and take-up of cable from the loaded reels by the use of friction rollers contacting the periphery of the reels. Examples are Hall, U.S. Pat. Nos. 3,184,082 and 3,325,118; and Woodruff, U.S. Pat. No. 4,228,967. Skalleberg et al U.S. Pat. No. 5,123,602 discloses a drive for cable reels by the use of frictional contact of the reel periphery with a powered car tire as the roller. However these methods of reel rotation are not precise and braking of the reel by friction contact of the rollers/tires against the reel is less than optimal. Further, powered rotation, and prompt reversal of the rotation, is limited by slippage of the roller at the reel periphery.
It would be an advance in the art if a reel handler could be provided that allowed for precise powered rotation of reels with self-braking features and rapid, almost instantaneous reversal of reel rotation.
McVaugh, U.S. Pat. No. 3,820,673 allows for engagement of reels of varying sizes and permits transfer of one reel to a first location and return for a second reel.
Mechanically complex devices to rotate mounted reels are disclosed in, for example, Berry, III et al., U.S. Pat. Nos. 5,246,180 and 5,333,809. Berry, III et al. require the use of high torque electrical gear motors or motor/gear reducer combinations with drive screw and drive nut arrangements. Similar complex mechanisms are also used in the Berry, III et al. 5,333,809 portal traverse assembly to substantially vary the width between the spaced masts to engage reels of varying sizes. However these motors are complex and relatively heavy. The motors are also large, bulky and require the use of reducing gears to convert the high speed of the motors to the low speed, high torque necessary for controlled reel rotation.
It would be of great advantage if a reel handler could be provided that used motors and devices of few moving parts to engage and rotate reels of varying sizes and to raise and lower the reel to facilitate loading and unloading of the reels from a chassis and payout and take-up of cable from the reel.
Hirakawa et al., U.S. Pat. No. 4,460,135 discloses a mill roll stand that permits raising and lowering of a paper roll and movement of the movable frames holding the paper roll along a threaded shaft. Again this is a mechanism that can be easily damaged.
It would be a advance in the art if a reel handler could be provided that used rugged motors and devices of relatively few moving parts to minimize damage and breakdown of the reel handler during use.
Other devices have been used to load, unload, and in some cases unroll, round hay bales. For example, see Parker, U.S. Pat. No. 3,946,887; and Hostetler, U.S. Pat. No. 4,044,963. Hostetler allows the round bale to be unrolled by controlled positioning of the bale adjacent the ground surface and rolling the bale thereon upon movement of the vehicle. None of the prior art provides for the use of a compact, high torque/low speed motor that is contained within a reel lift arm.
It would be an advance in the art if an improved reel handler could be provided that incorporated a compact, high torque, low speed hydraulic motor within its supporting reel arm to rotate the reel.
The prior art does not provide a safety mechanism that reliably prevents inadvertent release of the engaged reels. Engagement of the reels is of critical importance during transportation of the reels at high speeds along public roads and highways.
It would be a significant advance in the art if a safety device could be provided that reliably prevented inadvertent release of engaged reels.
Accordingly, it is an object of the present invention to provide a hydraulic motor capable of operating under high torque and low speed, such motor being suitable for operation in a smaller space than prior art designs such as within a reel arm of a reel handler.
A further object of this invention is to provide a hydraulic motor capable of producing high torque and low speed without the need for multiple reducing gears to translate high speed motion into the resultant high torque and low speed to make the motor more reliable during use in, for example, a reel handler.
Another object of this invention is to provide a hydraulic motor which is capable of supporting a load at zero velocity without the need or requirement of an additional brake device to facilitate, for example, precise reel payout and take-up of a reel handler.
Yet another object of the present invention is to provide a hydraulic motor capable of almost instantaneous reversal allowing for a like reversal of any power transmission shaft to which the motor would be attached to facilitate, for example, precise reel payout and take-up of a reel handler.
Another object of the present invention is to provide an improved reel handler with relatively few moving parts to engage and rotate reels of varying sizes and to raise and lower the reel to facilitate loading and unloading of the reels from a chassis, and payout and take-up of cable from the reel.
Yet a further object of the present invention is to provide a simple safety device for a reel handler that reliably prevents inadvertent release of engaged reels.
Other objects will appear hereinafter.


The control apparatus of the present invention is applied to a hybrid vehicle having an internal combustion engine that is capable, during operation, of changing over its operational mode to lean combustion or to stoichiometric combustion. The control apparatus preferentially selects an operational mode having high system efficiency in relation to the requested power, and selects the stoichiometric combustion mode (S104) when, under the specific condition that the system efficiency is higher in the lean combustion mode as compared to the EV mode and moreover is lower in the stoichiometric combustion mode as compared to the EV mode, also the temperature (Tnc) of an exhaust purification catalyst is less than or equal to a first predetermined value (Tα) (S101, S102).

Per se known is a control apparatus that is applied to a hybrid vehicle including an internal combustion engine that can change over to a lean combustion mode and to a stoichiometric combustion mode and that incorporates an EGR device through which exhaust is circulated, a first motor-generator, and a second motor generator, and that, during execution of an EV mode in which combustion in the internal combustion engine is stopped and the vehicle travels by using the second motor-generator as a source of propulsion power, suppresses decrease of the temperature of an exhaust purification catalyst in the exhaust passage by circulating exhaust through the EGR device while motoring the internal combustion engine with the first motor-generator (refer to Patent Document #1). Apart from the above, Patent Documents #2 through #4 in the Citation List below may be considered to be relevant to the present invention.