Fluid Pressure Patents (Class 137/413)
  • Patent number: 4153071
    Abstract: A mechanism for selectively distributing liquid flow to at least two separate outlet conduits includes a tank for receiving liquid and at least two tubular members having bellows-like sections mounted in the tank in flow communication with the associated outlet conduits. Actuator devices are connected for selectively compressing or extending the bellows-like sections to determine the elevations of the mouths of the tubular members within, or above, the liquid in the tank to thereby control the flow through the outlet conduits.
    Type: Grant
    Filed: July 27, 1977
    Date of Patent: May 8, 1979
    Assignee: Envirotech Corporation
    Inventors: Brent C. Black, P. Larry Hill
  • Patent number: 4119016
    Abstract: A hydraulic control device for use in a hydraulic system having a pump supplying fluid from a reservoir to a working circuit. The control device detects leaks in the working circuit by monitoring the level of hydraulic fluid in the reservoir. In the event of a drop in the level of hydraulic fluid beyond a predetermined low level, the control device automatically diverts the fluid output side of the pump to the fluid input side to prevent further loss of fluid in the working circuit and to safeguard against cavitation in the pump due to the low level of fluid in the reservoir. The control device also senses excessive pressure peaks in the working circuit and operates to relieve the excessive pressure peaks by automatically venting a portion of the fluid on the output side of the pump to the reservoir.
    Type: Grant
    Filed: July 1, 1976
    Date of Patent: October 10, 1978
    Assignee: International Harvester Company
    Inventors: Christian Pfeil, Hans Breidenbach
  • Patent number: 4116586
    Abstract: A housing contains a slidable spool operable to port a first pressurized fluid line to a fluid motor, and a housing reservoir has a float movable with a fluid level. The motor drives a pump which "pumps down" the reservoir. A second pressurized fluid line is directed through a primary fixed orifice and against one end of the spool, acting against a spring bias, and is permitted to exit through an end orifice to the reservoir. The float moves in response to the fluid level and operates to shut off the end orifice flow, thereby building up backpressure to shift the spool, and thus varying outlet flow from the valve in accordance with the reservoir level. Therefore, the reservoir is pumped down in accordance with reservoir build-up.
    Type: Grant
    Filed: May 9, 1977
    Date of Patent: September 26, 1978
    Assignee: Cincinnati Milacron Inc.
    Inventors: Richard Davidson Forney, Richard Samuel Hernandez, Richard Anderson Curless
  • Patent number: 4101174
    Abstract: A liquid level sensor for determining the fluid level in a container and for controlling a fluid inlet to the container in response to the fluid level therein. The sensor includes a buoyant liquid-filled flexible conduit or liquid-filled hinged pipe member in the container and a pressure transducer responsive to the head pressure of the liquid in the flexible conduit or hinged pipe member.
    Type: Grant
    Filed: March 25, 1977
    Date of Patent: July 18, 1978
    Assignee: Continental Oil Company
    Inventor: Thomas R. Miller
  • Patent number: 4057076
    Abstract: A valve connects a waste water producing unit to a vacuum sewer. The valve comprises a collecting chamber receiving waste water, a closing member a connection between the collecting chamber and the vacuum sewer, a pressure controlled operating device for moving the closing member, a float moved by liquid level variations in the collecting chamber, and a pilot valve. The operating device of the closing member is controlled by the latter and the latter is controlled by the float. The operating device is constantly in connection with the vacuum system of the vacuum sewer and is influenced by the pilot valve so that the vacuum in the operating device is either increased or decreased to obtain a pressure difference in the operating device which pressure difference causes the valve opening movement.
    Type: Grant
    Filed: May 13, 1976
    Date of Patent: November 8, 1977
    Inventors: Martti Varis, Krister Nordberg
  • Patent number: 3954351
    Abstract: A device for sensing and controlling liquid level in a reservoir container. The device includes a sensing element in the form of a displacer which enters the liquid through the surface and displaces a predetermined volume. The displacer is located in a surge tank into which the liquid is initially fed and from which it is supplied to the reservoir. The displacer is mounted on an arm of a lever, the displacer being counterbalanced to respond to a liquid level in the surge tank. The lever carries a switch actuating mechanism which is moved in response to a change in the liquid level in the surge tank and which controls actuation of a single acting piston pump air motor to supply liquid to the surge tank.
    Type: Grant
    Filed: December 27, 1974
    Date of Patent: May 4, 1976
    Assignee: Nordson Corporation
    Inventors: Charles H. Scholl, Alan B. Reighard
  • Patent number: 3930423
    Abstract: A power shift transmission having a fluid pressure control system having an intake screen and level control located centrally in the bottom of the sump and a pump and regulator valve supplying pressure to the shift control system and to a sump oil level control. The sump oil level control has a small float controlling a relay valve to control an oil level control valve connecting an elevated oil reservoir for gravity feed to fill the sump and pressure return to the reservoir to dump the sump. When the transmission input and pump is not driven, there is no pressure in the chambers at opposite ends of the differential land area level valve and balanced springs hold the level valve in a central closed position blocking flow to and from the reservoir, to the sump and from the pressure line so the oil level control is inoperative. When the transmission input is driven, a small flow of line pressure is supplied through an inlet restriction to each chamber.
    Type: Grant
    Filed: November 29, 1974
    Date of Patent: January 6, 1976
    Assignee: General Motors Corporation
    Inventor: James T. Craig