Selective Diverse Supply Or Exhaust Paths For Distributor Motor Patents (Class 91/278)
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Patent number: 10883242Abstract: A double-acting hydraulic impact hammer includes a drop weight and an inner hydraulic piston. The drop weight is arranged to be driven in an upward and downward direction and the drop weight acts on a pile during its downward motion. The piston has a voided internal area defining a piston volume which is arranged to receive a piston rod and along which the piston extends and retracts axially. The piston volume is in sealed hydraulic communication with the hollow rod volume to form a first volume which changes size as the piston moves along the piston rod whereby the application of hydraulic pressure to the first volume biases the piston towards its extended position. The hammer includes a bore and a collar. The collar forms an outer piston having a working surface which when exposed to hydraulic fluid has sufficient surface area to lift the piston and the drop weight.Type: GrantFiled: June 29, 2017Date of Patent: January 5, 2021Assignee: DAWSON CONSTRUCTION PLANT LIMITEDInventors: Stephen Desborough, David Andrew Brown
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Patent number: 10150209Abstract: Provided is a hydraulic hammering device having improved hammering efficiency and of low cost. A piston has a valve switching groove between large-diameter sections thereof. A cylinder has three control ports at positions corresponding to the valve switching groove. A switching valve mechanism has a valve presser for always pressing a valve in one direction and also has a valve controller for moving, when supplying pressurized oil, the valve in the opposite direction against the pressing force of the valve presser. A valve control port communicates with the valve controller so as to supply the pressurized oil to the valve controller and is separated from a piston front chamber and a piston rear chamber. Only either a piston retraction control port or a piston advance control port communicates with the valve control port depending on advance or retraction of the valve switching groove.Type: GrantFiled: January 30, 2015Date of Patent: December 11, 2018Assignee: Furukawa Rock Drill Co., Ltd.Inventors: Toshio Matsuda, Tsutomu Kaneko
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Patent number: 8578708Abstract: In various embodiments, compressed-gas energy storage and recovery systems feature one or more valves, which may be disposed within end caps of cylinder assemblies in which gas is expanded and/or compressed, for admitting fluid to and/or exhausting fluid from the cylinder assembly.Type: GrantFiled: November 30, 2011Date of Patent: November 12, 2013Assignee: SustainX, Inc.Inventors: Benjamin R. Bollinger, Lee Doyle, Michael Neil Scott, Troy O. McBride, Andrew Shang
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Patent number: 8069928Abstract: A percussive device and method having, inside a machine housing (3), a reciprocally moveable percussive piston (2), the movement of which is controlled by a control valve (5), which is arranged to alternatively connect a chamber to a pressure source and to low pressure in dependence on a signal corresponding to the axial position of the percussive piston, and a valve (16) arranged to allow adjustment of the axial position of the percussive piston at which the signal is transmitted, by opening and blocking of a connection between one or more control channels (10, 11, 12, 13) and the control valve.Type: GrantFiled: September 12, 2007Date of Patent: December 6, 2011Assignee: Atlas Copco Rock Drills ABInventor: Peter Birath
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Patent number: 7207116Abstract: A main spindle of an air saw is reciprocated by sliding a piston in a cylinder chamber with the pressure of air supplied to the cylinder chamber via an air supply path so as to alternately apply the air pressure to pressure-receiving surfaces of a back plate and a front plate, wherein a rear air-cushion chamber is formed in a portion for fixing a return spring for urging the back plate toward the center of a cylinder while a front air-cushion chamber is formed in a portion for fixing a return spring for urging the front plate toward the center of the cylinder, so that the front and rear balance is maintained.Type: GrantFiled: September 9, 2002Date of Patent: April 24, 2007Assignee: Kuken Co., Ltd.Inventor: Akinori Nakamura
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Patent number: 7137330Abstract: A fluid powered vehicle seat adjustment system comprising a fluid actuator a source of pressurized hydraulic fluid and a controller. The fluid actuator including first and second inlet/outlet conduits, and the controller selectively controlling and directing pressurized fluid selectively to either the first or second inlet/outlets of the actuator. The actuator further comprising actuator isolation valves associated with each of the first and second inlet/outlets of the actuator. Each actuator isolation valve allowing a flow of fluid from the actuator only when pressurized fluid is supplied to the actuator and other isolation valve in order to prevent movement of the actuator except when pressurized fluid is supplied to the actuator.Type: GrantFiled: November 24, 2004Date of Patent: November 21, 2006Assignee: Lear CorporationInventor: Hugh H. Christopher
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Patent number: 5752571Abstract: An apparatus for generating impacts which has a hydraulic cylinder and a reciprocating piston. The hydraulic cylinder has an impact chamber, a cavity which receives and diverts fluid, and a throat which connects the impact chamber with the cavity. When the pressure line is connected to the cavity, the piston is lifted to an upper position. When the overflow line is connected to the cavity, the piston drops down such that the piston enters and covers the throat at the impact chamber. The pressure in the chamber remains low as the chamber is sealed by the piston entering the throat, where the energy loss is insignificant. The piston enters into the throat such that it is stopped and presses against the fluid inside the impact chamber, and thereby generates an impact therein. The piston is lifted up to repeat the cycle, when the cavity is connected to the pressure line.Type: GrantFiled: December 15, 1995Date of Patent: May 19, 1998Inventor: Zinoviy A. Sapozhnikov
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Patent number: 5669281Abstract: Method and apparatus for controlling a percussive machine by determining, during the phase of rebound of a piston following impact, the existence of an instantaneous flow rate of fluid flowing from a top chamber toward the high-pressure fluid feed circuit. The instantaneous flow rate is determined on the basis of the differential pressure between the top chamber and the high pressure fluid feed circuit. If a flow rate is detected, a control device is fed with pressurized fluid so as to shift a selector piston in a direction for lengthening the stroke of the striking piston.Type: GrantFiled: November 30, 1995Date of Patent: September 23, 1997Assignee: Etablissements MontabertInventor: Jean S. Comarmond
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Patent number: 5129466Abstract: A hydraulically operated striking mechanism includes a contact pressure control member held at least temporarily in contact with an insertion end of a drilling tool by a mechanism which applies a restoring force in the striking direction. A control conduit is connected by way of the contact pressure control member either to a pressure conduit or to a pressure return conduit. The control conduit actuates a switching element so that a control unit which alternatingly switches the movement of the striking piston performs a reversal movement into an operating stroke position at an earlier or later point in time during the return stroke of the striking piston and thus actuates the operating stroke of the striking piston in the striking direction.Type: GrantFiled: September 9, 1991Date of Patent: July 14, 1992Assignee: Krupp Maschinentechnik Gesellschaft mit beschrankter HaftungInventors: Robert-Jan Bartels, Hans-Dieter Piotrowski
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Patent number: 4413687Abstract: In a hydraulic rock drill the valve (27) is controlled by two control lines (37, 42), each control line having a plurality of branches with ports (38-41 and 43-46) which open into the hydraulic cylinder of the rock drill.A valving pin (48) is slidable in a bore that intersects all of the branches of both control lines. By axially displacing the pin, the operator can pre-select the stroke length by deactivating some of the control lines and thereby the impact energy per blow. The control lines are deactivated in a predetermined bound relationship to each other.Type: GrantFiled: February 13, 1981Date of Patent: November 8, 1983Assignee: Atlas Copco AktiebolagInventor: Ake T. Eklof
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Patent number: 4342255Abstract: An oscillator actuated hydraulic impulse of the type including a spool valve actuated by an alternating signal from an oscillator to switch the hydraulic pressure in a double acting cylinder in order to cause reciprocating motion of a piston which strikes a boring tool. The hydraulic impulse device further includes a means for controlling the transition from the impulse stroke to the return stroke of the piston. In some embodiments, the hydraulic impulse device may further include a means for varying the duration of the impulse stroke and the return stroke of the piston.Type: GrantFiled: October 30, 1980Date of Patent: August 3, 1982Assignee: Mitsui Engineering and Shipbuilding Co., Ltd.Inventors: Takeo Watanabe, Makoto Matsuda
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Patent number: 4207801Abstract: A hydraulically-operated road breaker comprises a casing with a tool mounting and housing an oscillatory piston/striker and cylinder arrangement. A sequence valve mounted in the casing controls pressurization and exhausting of the piston to produce power and return strokes of the piston. Pilot port means positioned in the cylinder of the device are uncovered, at the end of each return stroke of the piston, to allow a valve-actuating flow of hydraulic fluid through the port means to change over the sequence valve and thereby cause stroke reversal of the piston. Manually-operable stroke selection means provide for adjustment of the position of the piston in the cylinder at which the valve-actuating flow occurs, whereby to vary the piston stroke.Type: GrantFiled: November 8, 1977Date of Patent: June 17, 1980Assignee: A. F. Hydraulics LimitedInventor: Lionel A. Reynolds
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Patent number: 4172411Abstract: A hydraulic hammer wherein the reciprocal motion of a drill-striking piston is operated by means of a spool valve for switching hydraulic pressure to a double-acting cylinder depending upon the position of the piston. The hydraulic hammer further includes a self starter means which assures activation of the hammer whenever hydraulic pressure is applied to the hydraulic hammer and a means for compensating for variations in boring conditions such that energy is efficiently delivered by the drill striking piston.Type: GrantFiled: June 6, 1977Date of Patent: October 30, 1979Assignee: Mitsui Engineering & Shipbuilding Co., Ltd.Inventors: Makoto Matsuda, Takeo Watanabe
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Patent number: 4006665Abstract: This disclosure relates to a percussion tool which includes a housing having a chamber reciprocally mounting a piston with first and second pressure ducts at opposite ends of the latter and a control duct therebetween as well as a return duct in fluid communication with the chamber at a point intermediate the points of entry of the first and second pressure ducts and reciprocal valve means for controlling the reciprocal motion of the piston, the improvement including a plurality of branch ducts of the control duct opening into the chamber in such a fashion that the branch ducts are successively opened and closed during the reciprocation of the piston.Type: GrantFiled: May 1, 1975Date of Patent: February 8, 1977Assignee: Fa. Ingenieur Gunter Klemm Spezialuntrnehmen fur BohrtechnikInventor: Gunter Klemm