Abstract: The present invention provides an apparatus and method for manipulating plasmons. The apparatus comprises a support structure and two or more plasmon-responsive elements. The plasmon-responsive elements are disposed adjacent the support structure and configured for interaction with electromagnetic radiation and generation of a plurality of plasmons. At least a first of the plasmon-responsive elements is configured to manipulate interaction of at least some of the plurality of plasmons with at least a second of the plasmon-responsive elements.

Abstract: A fluid system is connected to a three chamber fluid cylinder. The effective pressure responsive areas of two of the pressure chambers are equal such that when fluid at a selected rate of flow and at a predetermined pressure is communicated to one of the chambers, a force of a predetermined magnitude is generated to cause contraction of the fluid cylinder at a predetermined rate. A servo valve is disposed in the system between the inlet and outlet of a fluid pump to selectively direct fluid to either of the equal pressure chambers to selective expand or contract the fluid cylinder. The fluid system further comprises an accumulator and a directional control valve adapted to communicate a third chamber of the fluid cylinder to the accumulator. The accumulator maintains the pressure in the third fluid chamber to exert a force on the fluid cylinder balancing a selected load that the cylinder may be carrying during the expansion and contraction stages of the cylinder.

Abstract: A single rod three chamber fluid cylinder is driven in an initial rapid advance forward stroke by a main pump, pumping fluid through a proportional directional control valve to act against a first equal area at the head end of the piston. Fluid expelled from a second equal area at the rod side of the piston is returned to the reservoir through a proportional directional control valve which is in a first position while a two position valve is in its first position allowing an accumulator to fill a third chamber exposed to a third area of the head side. When shifting to the feed stroke, the two position valve switches to its second position disconnecting the accumulator to the third area and connecting the main pump to the third area while also connected to the first equal area. Upon the return stroke of the piston, the fluid from the first equal area is returned to the sump and the fluid from the third area is routed to the accumulator.

Abstract: A hydraulically powered lift system for raising and lowering lift platforms of relatively large area employs two sets of hydraulic cylinders hydraulically connected in parallel in a closed loop system to a main system pump via a directional control valve. The piston rods of both sets of cylinders are mechanically connected to the lift platform, but the mechanical interconnections between the rods of one set of cylinders and the lift platform differ from those employed between the rods of the other set of cylinders and the lift platform. The differing types of mechanical interconnections establish a mechanical advantage of one set of cylinders which is substantially constant throughout a working stroke while the mechanical advantage of the other set of cylinders is variable over the stroke, the parallel hydraulic connections of the cylinders distributing the fluid supplied by the pump to maintain a common equal pressure at all cylinders.

Abstract: A single rod three chamber fluid motor is driven in a forward stroke which includes a rapid initial advance followed by a relatively short and slow feed stroke under high pressure. The rapid advance is performed by a closed loop system in which a high displacement main pump, pumps fluid to act against a first equal area at the head side of the piston and receives fluid expelled from a second equal area at the rod side of the piston while an accumulator maintains the third chamber exposed to a third area of the head side of the piston filled with fluid. Upon shifting to the feed stroke, the main pump is disconnected and a feed pump applies pressure to both of the first and third areas at the head side of the piston and receives fluid expelled by the second equal area and from a charge pump. The access fluid added to the feed pump circuit by the charge pump is returned via the accumulator to the charge pump sump during the return stroke of the piston.

Abstract: A pilot control circuit including a pilot pressure pump and a float center connected directional control pilot valve is provided with a warm up circuit for warming up the hydraulic fluid in the pilot circuit. The warm up circuit includes a pair of branch conduits commonly connected to the high pressure side of the pilot pressure pump and respectively connected via flow restriction to the pilots of a primary directional control valve. Fluid can flow from the branch conduits through the pilots and then through the centered pilot valve to the low pressure side of the pilot pump, allowing a warm up circulation of fluid through the entire pilot circuit while its control valve remains centered.

Abstract: A self-regulating hydraulic control circuit for controlling the flow of fluid to and from the cylinder of a double-acting hydraulic motor employs two pumps, one of which supplies fluid at a relatively high pressure and low displacement while the second pump is a relatively high displacement pump which operates only against a relatively low pressure requirement. The system is especially adapted for applications where, during a working stroke, the piston of the hydraulic motor moves from a start position through a first portion of the stroke during which the piston encounters but a minimal resistance to movement and then suddenly encounters a high resistance to movement. One example of such an application would be a press in which, at some point during the stroke of the piston, a tool carried by the piston initially encountered a workpiece.

Abstract: A hydraulic drive system for driving a platen in forward and return reciprocatory strokes includes a hydraulically driven reciprocable piston and a reversible rotary hydraulic motor having a crank coupled to the platen by a link. A hydraulic circuit employs a variable output pump connected via a reversible direction control valve to drive the piston and crank in unison to cooperatively drive the platen. The piston and crank motor are connected in parallel to the pump and the pump output is advantageously distributed variably between the piston and motor during the stroke cycle. Where the stroke of the platen is vertical, the system may include a hydraulic counterbalance circuit to counterbalance the weight of the platen. The pump output may be varied to control the velocity of the platen at selected points in its stroke.

Abstract: An hydraulic control system coordinates the rate of rotation of a workpiece about a fixed axis with the radial displacement of an end facing tool from that axis to maintain a constant feed rate or cutting speed of the workpiece to the tool as the tool moves radially across the workpiece. A doubled rodded piston has one rod connected to drive the tool and a second rod which projects into the chamber of a master cylinder. Fluid displaced from the master cylinder by tool driving movement of the piston is employed to drive a slave piston coupled to a speed control of a variable speed motor which drives the workpiece in rotation.

Abstract: A fluid system is disclosed as having a variable displacement fluid pump connected in a closed-loop circuit to a multi-pressure chamber fluid cylinder. The effective pressure responsive areas of two of the pressure chambers are equal such that when fluid at a selected rate of flow and at a predetermined pressure is communicated to one of the chambers, a force of a predetermined magnitude is generated to cause contraction of the fluid cylinder at a predetermined rate. Similarly, when fluid at the same rate and flow is communicated to the other pressure chamber, a force of the same predetermined magnitude is generated to expand the fluid cylinder. A directional control valve is disposed in the closed circuit between the inlet and outlet of the fluid pump so as to selectively direct fluid to either of the pressure chambers to selectively expand or contract the fluid cylinder.

Abstract: A fluid system has a variable displacement pump connected in a closed-loop circuit to a fluid cylinder having a piston and one connecting rod extending from the piston through an opposite side wall such that the effective pressure responsive areas on the opposite sides of the piston are unequal. The fluid system includes a circuit which permits an unequal displacement cylinder to be connected in a closed-loop circuit to a fluid pump.

Abstract: A hydraulic motor having a housing and a shaft journaled for rotation along the longitudinal axis of the housing. The shaft carries an eccentric on which is rotatably mounted a bearing block. The housing has a plurality of hydraulic cylinders grouped about the axis of the shaft in a common plane normal to the axis of rotation of the shaft with each cylinder having a hollow piston displaceable therein and biased in a direction toward the bearing block. The shaft and the eccentric have inlet and outlet passages communicating with the bearing block and adapted to communicate a source of hydraulic fluid pressure and an exhaust means respectively therewith. Means are provided on the eccentric for separating these passages from one another with the bearing block having a port communicating fluid from the aforementioned passages to the piston interior, whereby fluid pressure may be admitted to the cylinders in turn, one after another, during the operation of the motor to exert a direct thrust on the eccentric.

Abstract: A fluid system having a variable displacement fluid pump connected in a closed-loop fashion to a hydraulic motor-driven winch of the spool type. A directional control valve connected between the pump and motor selectively directs fluid to the hydraulic motor-operated winch to control the direction of movement thereof. The hydraulic winch is provided with a pressure responsive brake that is normally set to brake the winch and prevent its operation, while fluid under pressure communicated to the brake will release the same and permit the winch to operate. A separate source of fluid pressure is provided and selectively communicated to the hydraulic brake of the winch through a directional control valve, while a second control valve is provided for exhausting the control pressure to the reservoir in the event the main system pressure drops below a predetermined value.

Abstract: A closed-loop hydrostatic drive unit having a variable displacement fluid pump driven by an electric motor for generating high-pressure fluid adapted to be communicated to a fluid motor and returned to the fluid pump via a high-pressure filter. The closed-loop hydrostatic drive unit is mounted to a rectangularly-shaped reservoir housing having upper and bottom surfaces connected by side walls and end walls to define therein a chamber for the storage of fluid at a low pressure which is communicated to the fluid pump via a charge pump and suitable conduits and check valves. In a first embodiment of the invention the interior of the reservoir housing is divided by means of a partition to define the fluid-holding chamber, while the remaining portion of the reservoir housing defines a separate chamber for the mounting and storage of the high-pressure filter and/or other selected fluid power components.

Abstract: A fluid system having a source of fluid pressure such as a fluid pump connected to a fluid user such as a fluid motor is provided with a directional control valve between the fluid source and the fluid user for selectively controlling its direction of movement. The directional control valve is a three-position, tandem-center, pilot operated four-way valve which, in the preferred embodiment of the invention, is modified to include a two-position, four-way directional control valve between the pilot valve and the main valve of the system to provide a hydraulic memory.

Abstract: A closed-loop hydrostatic drive unit having a variable displacement fluid pump driven by an electric motor for generating high-pressure fluid adapted to be communicated to a fluid motor and returned to the fluid pump via a high-pressure filter. The closed-loop hydrostatic drive unit is mounted to a rectangularly-shaped reservoir housing having upper and bottom surfaces connected by side walls and end walls to define therein a chamber for the storage of fluid at a low pressure which is communicated to the fluid pump via a charge pump and suitable conduits and check valves. In a first embodiment of the invention the interior of the reservoir housing is divided by means of a partition to define the fluid-holding chamber, while the remaining portion of the reservoir housing defines a separate chamber for the mounting and storage of the high-pressure filter and/or other selected fluid power components.

Abstract: A fluid system having a variable displacement fluid pump connected in a closed-loop fashion to a pair of inlet ports of a fluid motor of the type having two output shafts and a fluid pressure responsive means operable upon communication with fluid pressure through said inlet ports to translate said fluid pressure to one of the output shafts in the form of a high torque output while rotating one shaft at a low speed. The fluid pressure responsive means of the fluid motor is further operable to translate fluid pressure to the other of the drive shafts in the form of a low torque output while rotating the other shaft at a high speed. Suitable clutching means responsive to selective operation of the system are provided for alternate and independent coupling of the motor output shafts to a common system drive shaft to provide an output of which the speed and torque may be selectively varied from a high speed-low torque output to a high torque-low speed output.