Patents by Inventor David P. Smith

David P. Smith has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Fluid system for two hydraulic circuits having a common source of pressurized fluid
    Patent number: 6681568
    Abstract: A fluid system having a common source of pressurized fluid is provided to selectively control the speed and/or pressure of a first hydraulic circuit while also providing flow/pressure priority to a second hydraulic circuit. The first hydraulic circuit includes a first electrically controlled proportional relief valve connected between the source of pressurized fluid and a first fluid actuator and a second electrically controlled proportional relief valve connected between the reservoir and a point downstream of the first electrically controlled proportional relief valve. The second hydraulic circuit is connected to the source of pressurized fluid in parallel with the first hydraulic circuit.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: January 27, 2004
    Assignee: Caterpillar Inc
    Inventor: David P. Smith
  • Hydro-mechanical combiner
    Patent number: 6651794
    Abstract: A power combining device is provide for use in a work system to combine mechanical power and hydraulic power. The power combining device includes a first rotatable input/output member connected to a power source, a second rotatable input/output member connected to a working member. A valving plate, a drive sleeve and a camplate are drivingly connected to the first rotatable input/output member. A rotating barrel having a plurality of piston disposed therein to define pressure chambers is drivingly connected to the second rotatable input/output member and operative in cooperation with the valving plate to control pressurized fluid within the pressurized chambers. The subject power combining device is compact and cost effective to produce.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: November 25, 2003
    Assignee: Caterpillar Inc
    Inventor: David P. Smith
  • Hydraulic regeneration system
    Publication number: 20030213238
    Abstract: A hydraulic regeneration system for a work machine is provided. The hydraulic regeneration system includes a first hydraulic actuator having a first chamber and a second chamber, a second hydraulic actuator having a third chamber and a fourth chamber, and a source of pressurized fluid. A first directional control valve is disposed between the source of pressurized fluid and the first chamber of the first hydraulic actuator and the third chamber of the second hydraulic actuator. A second directional control valve is disposed between the source of pressurized fluid and the second chamber of the first hydraulic actuator and the fourth chamber of the second hydraulic actuator. An accumulator may also be used to store pressurized fluid and selectively supply pressurized fluid to increase the efficiency of the work machine.
    Type: Application
    Filed: May 17, 2002
    Publication date: November 20, 2003
    Applicants: Caterpillar Inc, Shin Caterpillar Mitsubishi Ltd.
    Inventor: David P. Smith
  • System for definable single lever control shift pattern joint
    Patent number: 6631653
    Abstract: A single lever control assembly that limits motion due to the inherent design of the assembly. In other words, no additional components are required to limit the motion of the single lever control assembly. The assembly includes two U-shaped members each having a base and parallel legs extending from the base, a lever connected to one of the U-shaped members and a pivot block interconnecting the parallel legs for allowing the U-shaped members to rotate relative to one another. The assembly has at least one of the parallel legs having a projection that engages one of the parallel legs of the other U-shaped member. In general, the single lever control assembly is a type of modified universal joint whose movement is limited by a projection.
    Type: Grant
    Filed: December 6, 2000
    Date of Patent: October 14, 2003
    Assignee: Caterpillar Inc.
    Inventors: Chad T. Brickner, John R. Connolly, Paul Gilbert, Thomas J. Hajek, Jr., Rudy V. Mills, David P. Smith
  • Variable pressure relief valve
    Publication number: 20030183282
    Abstract: A single stage, electrically controlled variable pressure relief valve assembly is provided that uses a valving element assembly slideably disposed within a housing having first and second inlet and outlet ports, the valving element assembly has a differential area defined thereon which acts in cooperation with an electrically controlled coil assembly to proportionally control the flow of fluid between the inlet port and an outlet ports of the housing. The valving element assembly has inlet and outlet ports that are oriented generally perpendicular to the flow of the fluid through the valving element assembly to effectively offset the effects of flow forces acting on the valving element.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 2, 2003
    Inventor: David P. Smith
  • FLUID SYSTEM FOR TWO HYDRAULIC CIRCUITS HAVING A COMMON SOURCE OF PRESSURIZED FLUID
    Publication number: 20030182938
    Abstract: A fluid system having a common source of pressurized fluid is provided to selectively control the speed and/or pressure of a first hydraulic circuit while also providing flow/pressure priority to a second hydraulic circuit. The first hydraulic circuit includes a first electrically controlled proportional relief valve connected between the source of pressurized fluid and a first fluid actuator and a second electrically controlled proportional relief valve connected between the reservoir and a point downstream of the first electrically controlled proportional relief valve. The second hydraulic circuit is connected to the source of pressurized fluid in parallel with the first hydraulic circuit.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 2, 2003
    Inventor: David P. Smith
  • System and method for starting an engine
    Publication number: 20030121265
    Abstract: A system and method for starting an engine having a crankshaft is provided. Pressurized fluid is stored in an accumulator. A flow of pressurized fluid is released from the accumulator. The flow of pressurized fluid released from the accumulator is directed to a pump that is operatively engaged with the crankshaft of the engine. The flow of pressurized fluid drives the pump to generate a rotation of the crankshaft and thereby start the engine.
    Type: Application
    Filed: November 25, 2002
    Publication date: July 3, 2003
    Applicant: Caterpillar Inc.
    Inventors: Thomas J. Hajek, David P. Smith
  • Hydraulic quick drop circuit
    Publication number: 20030121410
    Abstract: A fluid circuit for raising and lowering an implement including a quick drop valve member movable between at least a first position and a second position, the first position corresponding to a non-quick drop hydraulic fluid flow path of the fluid circuit and the second position corresponding to a quick drop hydraulic fluid flow path of the fluid circuit, the quick drop valve member being movable between at least the first and second positions based on pressures in the fluid circuit produced by hydraulic fluid. The fluid circuit further including a control system configured to selectively apply a biasing force against the quick drop valve member biasing the quick drop valve in the first position, the control system providing the biasing force independent of pressures in the fluid circuit produced by the hydraulic fluid.
    Type: Application
    Filed: December 28, 2001
    Publication date: July 3, 2003
    Inventors: David P. Smith, Rudy V. Mills, Robert A. Aarestad, Chad T. Brickner
  • METHOD, SYSTEM AND COMPUTER SOFTWARE FOR ONLINE ORDERING OF CUSTOM PROBE ARRAYS
    Publication number: 20030120432
    Abstract: A genomic portal system is described that receives user-selected identifiers of potential probes. The system determines verified probes corresponding to the identifiers and generates a custom probe array design. The system then displays the custom probe array design to the user via a graphical user interface and receives a user selection specifying acceptance, modification, or rejection of the design. The system provides the user with the accepted or modified custom probe array. The system may also enable a number of users to share space on a custom probe array. Another optional feature is to enable a number of users to share in ordering portions of a lot of catalog probe arrays to take advantage of economies of scale from lot-size purchases.
    Type: Application
    Filed: November 26, 2002
    Publication date: June 26, 2003
    Applicant: Affymetrix, Inc.
    Inventors: Xue Mei Zhou , David P. Smith , Elizabeth M. Kerr , Lianne McLean , Shaw Sun , Michael A. Siani-Rose , Michael A. Mittman , Shawn H. Becker , Lee A. Jacobek
  • Hydro-mechanical combiner
    Publication number: 20030106764
    Abstract: A power combining device is provide for use in a work system to combine mechanical power and hydraulic power. The power combining device includes a first rotatable input/output member connected to a power source, a second rotatable input/output member connected to a working member. A valving plate, a drive sleeve and a camplate are drivingly connected to the first rotatable input/output member. A rotating barrel having a plurality of piston disposed therein to define pressure chambers is drivingly connected to the second rotatable input/output member and operative in cooperation with the valving plate to control pressurized fluid within the pressurized chambers. The subject power combining device is compact and cost effective to produce.
    Type: Application
    Filed: December 7, 2001
    Publication date: June 12, 2003
    Inventor: David P. Smith
  • Electro-hydraulic pump control system
    Publication number: 20030106314
    Abstract: A method is provided for controlling displacement of a variable displacement pump coupled to a load. The method includes determining an electrical signal to be applied to a proportional solenoid for a desired pump displacement based on known pump characteristics. The electrical signal is provided to the proportional solenoid. The displacement of the variable displacement pump is controlled based on the electrical signal to the proportional solenoid.
    Type: Application
    Filed: October 26, 2001
    Publication date: June 12, 2003
    Applicants: Caterpillar, Inc., Delaware Corporation
    Inventor: David P. Smith
  • Fluid system having variable pressure relief
    Publication number: 20030106315
    Abstract: A fluid control system includes a pressure supply and a valve arrangement having an inlet and an outlet and being in fluid communication with the pressure supply. The valve arrangement includes a relief operator configured to provide fluid communication between the inlet and the outlet of the valve arrangement in response to a predetermined pressure condition at said inlet. The valve arrangement is configured to provide fluid communication between the inlet and the outlet of the valve arrangement in response to an outlet pressure being greater than an inlet pressure.
    Type: Application
    Filed: December 10, 2001
    Publication date: June 12, 2003
    Inventor: David P. Smith
  • Compact pump or motor with internal swash plate
    Patent number: 6572344
    Abstract: A fluid translating device is provided that includes a first member having fluid inlet/outlet ports and a second member having a plurality of pistons disposed therein secured to a stationary central shaft. A camplate and port plate is disposed in the fluid translating device about the stationary central shaft and located between the first and second members. The camplate is in communication with the fluid inlet/outlet ports and the plurality of pistons is in mating contact with the port plate. An outer input/output member is secured about the camplate and is rotatably disposed about the first and second members to form a compact arrangement.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: June 3, 2003
    Assignee: Caterpillar Inc
    Inventors: Thomas J. Hajek, Jr., David P. Smith
  • COMPACT PUMP OR MOTOR WITH INTERNAL SWASH PLATE
    Publication number: 20030099551
    Abstract: A fluid translating device is provided that includes a first member having fluid inlet/outlet ports and a second member having a plurality of pistons disposed therein secured to a stationary central shaft. A camplate and port plate is disposed in the fluid translating device about the stationary central shaft and located between the first and second members. The camplate is in communication with the fluid inlet/outlet ports and the plurality of pistons is in mating contact with the port plate. An outer input/output member is secured about the camplate and is rotatably disposed about the first and second members to form a compact arrangement.
    Type: Application
    Filed: November 26, 2001
    Publication date: May 29, 2003
    Inventors: Thomas J. Hajek, David P. Smith
  • Method and apparatus for managing fluid pressure using an accumulator
    Patent number: 6564830
    Abstract: An accumulator assembly for managing pressurized fluid includes a housing and a partition provided in the housing moveable in response to fluid pressure imparted on the partition. A deflection member is disposed in the housing and is displaceable between a first position and a second position. The deflection member includes at least one deflection element including a first end and a second end and a flexing portion therebetween. The deflection member provides a resistive force between the first and the second positions of the deflection member in response to movement of the partition. The resistive force is substantially constant between the first and said second positions of the deflection member.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: May 20, 2003
    Assignee: Caterpillar Inc
    Inventor: David P. Smith
  • Portable worktop
    Publication number: 20020177397
    Abstract: A portable worktop that may be used for cleaning, preparing, or serving food has been developed. The portable worktop includes a work surface with an opening in the work surface. The worktop is held in place on a stable supporting base by a fastening ring. The opening is positioned over the supporting base so that the opening may be used for waste disposal.
    Type: Application
    Filed: May 28, 2002
    Publication date: November 28, 2002
    Inventor: David P. Smith
  • System for definable single lever control shift pattern joint
    Publication number: 20020066329
    Abstract: A single lever control assembly is disclosed that limits motion due to the inherent design of the assembly. In other words, no additional components are required to limit the motion of the single lever control assembly. The assembly includes two U-shaped members each having a base and parallel legs extending from the base, a lever connected to one of the U-shaped members and a pivot block interconnecting the parallel legs for allowing the U-shaped members to rotate relative to one another. The assembly has at least one of the parallel legs having a projection that engages one of the parallel legs of the other U-shaped member. In general, the single lever control assembly is a type of modified universal joint whose movement is limited by a projection.
    Type: Application
    Filed: December 6, 2000
    Publication date: June 6, 2002
    Inventors: Chad T. Brickner, John R. Connolly, Paul Gilbert, Thomas J. Hajek, Rudy V. Mills, David P. Smith
  • High force feel bumper with low final load
    Patent number: 6394431
    Abstract: The feel bumper includes a plunger disposed for movement by an input device along a predetermined path, and at least one damper element disposed to engage the plunger when in a predetermined initial position along the path corresponding to a desired operating position for exerting a first opposing feedback force against the plunger in opposition to movement thereof along the path in a first direction, the at least one damper element being yieldable to the plunger when moved in the first direction past the predetermined initial position and exerting a second opposing feedback force against the plunger in opposition to the continued movement of the plunger in the first direction through subsequent operating positions.
    Type: Grant
    Filed: March 21, 2001
    Date of Patent: May 28, 2002
    Assignee: Caterpillar Inc.
    Inventor: David P. Smith
  • Countermeasure apparatus for deploying interceptor elements from a spin stabilized rocket
    Patent number: 6279482
    Abstract: There is provided a countermeasure defense system against hostile missiles by employing non-explosive intercepting (“NEI”) elements 14 deployed by the spin stabilized rocket 10. The NEI are carried in a payload section 17 and contained by a sleeve assembly 16 which is removed by a drive mechanism 20 or a pyrotechnic device 152 after a countdown time delay programmed into the trigger release assembly 46 as controlled by the control unit 150. The drive assembly includes a drive rod 26 that is releasably held by a release assembly 46 a compressed coiled spring unit 30 drives the sleeve assembly 16 forward exposing the payload section 17 to the centrifugal force of the spin stabilized rocket propelling the NEI elements out from the rocket at constant angular velocity creating an interceptor cloud of elements.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: August 28, 2001
    Assignee: TRW Inc.
    Inventors: David P. Smith, Jane M. Lin
  • Face seal with inner and outer seal retainer members
    Patent number: 6224065
    Abstract: A face seal for forming a sealed condition between two spaced, opposed surfaces. The face seal includes an inner seal retainer member and an outer seal retainer member each defining an area having an axis therethrough. The inner and outer seal retainer members each having a first axial end portion, an opposite second axial end portion, and an axial extent as measured between the first axial end portion and the second axial end portion. The outer seal retainer member is disposed radially outwardly of the inner seal retainer member, defining a space therebetween. An elastomeric seal member having an axial extent longer than the axial extent of the first and second inner and outer seal retainer members is disposed in a predetermined portion of the space between the inner seal retainer member and the outer seal retainer member.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: May 1, 2001
    Assignee: Caterpillar Inc.
    Inventor: David P. Smith