Effective Area Of Working Member End Face Selectively Variable Patents (Class 92/6R)
  • Patent number: 5477932
    Abstract: An impact device includes a cylinder and a plunger which is received within the cylinder and movable in forward and rearward directions. The plunger includes a first and a second pressure receiving surface for receiving pressure of a pressurized fluid so as to apply force to the plunger in the forward and rearward directions, respectively. An additional pressure receiving surface is formed on the plunger for receiving the pressure from the pressurized fluid so as to apply force in the same direction as one of the first and second pressure receiving surfaces. A first control device is operable to selectively apply the pressure of the pressurized fluid to the additional pressure receiving surface.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: December 26, 1995
    Assignee: Teisaku Corporation
    Inventors: Shigeki Asakura, Tokan Okawa
  • Patent number: 5440968
    Abstract: A variable force cylinder device with a piston reciprocated by a pressurized fluid in a cylinder chamber, in which the piston has a large-diameter portion and a small-diameter portion, the cylinder chamber has a large-bore portion corresponding to the large-diameter portion of the piston and a small-bore portion corresponding to the small-diameter portion of the piston, and a variable force mechanism is provided for varying a pressure-receiving area of the piston under an interaction of the piston with the cylinder chamber varying depending on the phases of the piston stroke.
    Type: Grant
    Filed: November 30, 1993
    Date of Patent: August 15, 1995
    Assignee: SMC Kabushiki Kaisha
    Inventor: Akira Sekine
  • Patent number: 5317954
    Abstract: The present invention provides a pressure switch assembly for monitoring a source of fluid pressure. In one embodiment, the pressure switch assembly senses a variation of fluid pressure for actuation of a micro-switch to open or close an electric circuit. In another embodiment, the pressure switch assembly provides a self contained cluster of piston members which are selectively interengagable to permit a variety of pre-determined pressure ratings to act on the pressure switch assembly in response to a fluid pressure source, the cluster being manually reorganizable without adding or removing any parts to provide one valve assembly which may be responsive to a number of pre-selectable pressure ratings.
    Type: Grant
    Filed: April 3, 1992
    Date of Patent: June 7, 1994
    Inventor: Kip B. Goans
  • Patent number: 4986357
    Abstract: A subsurface well tool having a hydraulic piston and cylinder assembly actuator which is adapted to be connected to and controlled by a hydraulic control line extending to the well surface. The assembly has a cross-sectional area exposed to the hydraulic control fluid which increases in one direction of movement of the assembly and decreases in the opposite direction for reducing surface operating pressure problems. Preferably, one of the piston and cylinder includes a tapered surface, and includes a flexible seal between the piston and cylinder.
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: January 22, 1991
    Inventor: Ronald E. Pringle
  • Patent number: 4723479
    Abstract: A system of hydraulic tools utilizing removably, replaceable and substantially interchangeable valve assemblies, fluid reservoirs and hydraulic driving mechanisms. The fluid reservoir maintains the hydraulic fluid under moderate pressure. The valve assembly can contain a hydraulic pump for powering the driving mechanism. The hydraulic pump preferably has displacement varying means for changing the power transfer ratio of the pump. The hydraulic assemblies are removably received in a variety of tool bodies.
    Type: Grant
    Filed: June 24, 1987
    Date of Patent: February 9, 1988
    Inventor: William Gallentine
  • Patent number: 4452126
    Abstract: A pneumatic drive has at least one working cylinder composed of a pair of parallel stationary walls and a pair of walls which extend at right angles to the first pair and are movable relative thereto, towards and away from each other. This varies the volumetric content of the cylinder and changes one transverse dimension thereof. A piston is reciprocable in the cylinder and constructed of a plurality of sections which together define the piston surface that is exposed to the pressurized working medium of the drive. During the working stroke these sections move apart from one another so as to together define a piston surface of maximum area; during the idle (return) stroke the sections are moved together by an arrangement provided for this purpose, so that some of them are concealed behind or within others, thus reducing the piston surface to an area which may only amount to about 20% of the former area.
    Type: Grant
    Filed: April 9, 1982
    Date of Patent: June 5, 1984
    Inventor: Mitko Tomov
  • Patent number: 4080871
    Abstract: A pressure medium servo-motor, especially for servo-steering systems, in which a working piston operating in a working cylinder is provided with a piston pressure surface actuatable by the pressure in one working pressure chamber of the working cylinder for producing a servo-force directed in the sense of the relative movement of the working piston with respect to the working cylinder; the piston pressure surface of the working piston is thereby reduced with respect to the reference value fulfilling the equilibrium condition of the piston pressure forces in the neutral position of the working piston, by a reducing piston which includes a pressure disengaging surface actuatable by the pressure in the working pressure chamber and a relief pressure surface actuatable by the pressure in a relief pressure chamber.
    Type: Grant
    Filed: January 16, 1976
    Date of Patent: March 28, 1978
    Assignee: Daimler-Benz Aktiengesellschaft
    Inventors: Klaus Katz, Jaromir Bordovsky
  • Patent number: 3995535
    Abstract: An expansible chamber device in which a cylinder of preferably rectangular configuration supports a pair of opposing flaps pivotally attached to the corners of the cylinder. The flaps sealably and slidably engage the top surface of a piston disposed within the cylinder such that the surface area of the flaps together with the exposed surface area of the top surface of the piston between the flaps constitutes the effective working area of the device. This area is considerably greater than the area of the piston surface itself whereby overall efficiency of the chamber is increased.
    Type: Grant
    Filed: May 23, 1975
    Date of Patent: December 7, 1976
    Inventor: Russell Ozechowski