US3892165A - Rotary hydraulic jack device - Google Patents

Rotary hydraulic jack device Download PDF

Info

Publication number
US3892165A
US3892165A US348598A US34859873A US3892165A US 3892165 A US3892165 A US 3892165A US 348598 A US348598 A US 348598A US 34859873 A US34859873 A US 34859873A US 3892165 A US3892165 A US 3892165A
Authority
US
United States
Prior art keywords
pressure
piston
jack
rotary
oil
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US348598A
Other languages
English (en)
Inventor
Jean Lioux
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GAMET PRECISION SA ROUTE D'EPEGARD 27110 LE NEUBOURG FRANCE A CORP OF FRANCE
Original Assignee
LA PRECISION INDUSTRIELLE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LA PRECISION INDUSTRIELLE filed Critical LA PRECISION INDUSTRIELLE
Application granted granted Critical
Publication of US3892165A publication Critical patent/US3892165A/en
Assigned to GAMET PRECISION S.A., ROUTE D'EPEGARD 27110 LE NEUBOURG, FRANCE, A CORP OF FRANCE reassignment GAMET PRECISION S.A., ROUTE D'EPEGARD 27110 LE NEUBOURG, FRANCE, A CORP OF FRANCE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: LA PRECISION INDUSTRIELLE S.A., A CORP OF FRANCE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
    • B23B31/02—Chucks
    • B23B31/24—Chucks characterised by features relating primarily to remote control of the gripping means
    • B23B31/30—Chucks characterised by features relating primarily to remote control of the gripping means using fluid-pressure means in the chuck
    • B23B31/302—Hydraulic equipment, e.g. pistons, valves, rotary joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2231/00—Details of chucks, toolholder shanks or tool shanks
    • B23B2231/24—Cooling or lubrication means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2260/00—Details of constructional elements
    • B23B2260/004—Adjustable elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T279/00—Chucks or sockets
    • Y10T279/12—Chucks or sockets with fluid-pressure actuator
    • Y10T279/1208—Chucks or sockets with fluid-pressure actuator with measuring, indicating or control means

Definitions

  • ABSTRACT A rotary hydraulic jack device, intended for control- 0 ling a chuck of a machine tool, comprising a rotary [30] l Apphcatm Pnorny Dam hydraulic joint for the alternate placing of each of two Apr. ll. I972 Italy 2l/ compartments of the jack in communication respectively with a source of hydraulic fluid under pressure US. Cl.
  • the rotary chucks of hydraulically controlled machine tools are usually provided with rotary control jacks so as to avoid transmitting the force of the jack to the chuck by means of a rotary member which, due to the heavy loading, would wear rapidly.
  • the radially oriented non-return valves which it includes are strongly influenced by the centrifugal force.
  • this radial disposition associated with the employment of a common central piston for forcing open the two valves in turn by means of the extensions provided at the two ends of the said piston prevents the provision in the rotary jack of an axial passage which allows the manufacture on a lathe of a series of short articles from a long bar traversing the fixed headstock.
  • the impossibility of providing such an axial passage in the rotary jack has been accepted in said SWiss Specification and, in order to avoid unbalance, the hydraulic pressure accumulator is disposed axially.
  • the present invention aims to overcome these disadvantages and to provide a jack which is rotatable at high speed and has a normal axial passage therethrough.
  • the invention not only allows the maintenance of the pressure originally supplied to the jack, but also an increase in the effective pressure which is applied to the jack compartments.
  • a rotary hydraulic jack device comprises a rotary hydraulic joint for the alternate placing of each of two compartments of the jack in communication respectively with a source of oil (as hereinbefore defined) under pressure and with exhaust, each of two oil-flow paths from said rotary joint to the two compartments of the jack including a non-return valve which, for each of said paths is capable of being controlled to the open position by the hydraulic pressure in the other of said paths, the oil-flow path to each of the compartments of the rotary jack being in communication with a pressure accumulator constituted by a cylindrical cavity arranged longitudinally in the rotary tubular shaft of the jack, each cavity containing a compensating piston urged by a spring in opposition to the pressure of the oil.
  • the oil acts on the two sections of the piston to ensure the compression of the spring and, when the control pressure disappears, the non-return valve closes communication between the jack compartment and the exterior, whilst the spring compresses the oil in this compartment up to a pressure which is a multiple of the control pressure substantially in the ratio of the area of the large diameter section of the piston to the area of its smaller diameter section.
  • the jack Under these conditions, if the jack is perfectly oiltight, it can work with a limited control pressure for ensuring the movements and a first clamping. When this operation has been achieved, the operating pressure is reduced to a very low value with the object of permitting lubrication of the bearings of the radial joint transferring the pressure. At this time, however, the pressure which acts in the active compartment under consideration is multiplied in the ratio 8/5 in which 8 and s are, respectively, the larger area and the small area of each differential piston. For example, if 5].: 5, the operating pressure being 20 bars, the pressure developed after the over-pressure effect will be 20 X 5 bars.
  • the very low pressure for example 2 bars, which may be admitted into the jack during the time of use other than the operations of clamping and unclarnping, considerably limits the heating of the assembly and of the oil of the hydraulic generator since, in order to de' velop the same force in the jack, a pressure of 100 bars would have to be continually applied.
  • FIG. I is a schematic axial section view of a first embodiment of the invention, this Figure showing, for the sake of clarity, the members distributed in two different radial planes.
  • This Figure corresponds substantially to two radial sections inclined to one another at an acute angle and joined according to the line XX,
  • FIG. 2 is a schematic view ofa more evolved emobdiment of the invention, permitting compensation of possible losses of pressure oil and if necessary the creation of an overpressure,
  • FIG. 3 is an elevation of the rear of the jack shown schematically in FIG. 2,
  • FIGS. 4 and 5 are sections taken on the lines IV-IV and V-V respectively, of FIG. 3, the jack parts being shown in different positions in the upper and lower halves of these two Figures,
  • FIG. 6 is a section taken on the line VIVI of FIG.
  • FIG. 7 is a section taken on the line VIIVII of FIG. 6, and
  • FIGS. 8 and 9 are sections taken, respectively, on the lines VIIIVIII and IXIX of FIG. 5.
  • the numeral 1 designates the head of a cylinder 2 of a rotary hydraulic jack, the head I being fixed to the hollow spindle (not shown) of a machine tool.
  • the cylinder 2 contains an annular piston 3 formed integrally with a sleeve 4 provided, for example, with a screw-thread 5 for exerting a pull on a control member (not shown) of a workholding chuck (not shown) mounted at the other end of the spindle.
  • the annular piston 3 is traversed by a tubular rod 6 fixed to the cylinder 2 in a radial plane which bisects the solid acute angle between the two radial planes which together constitute the section shown in FIG. I.
  • FIGS. 2 to 9 For the practical construction of such a rod 6, and indeed for the construction of other details of the jack illustrated in FIG. I, reference should be made to FIGS. 2 to 9, since the embodiment shown in these latter Figures has numerous points in common with that illustrated in FIG. I.
  • the piston 3 defines in the cylinder 2 two compartments A and B which can be placed under pressure alternately by means described hereafter, the compartment B receiving oil through the interior of the rod 6.
  • the cylinder 2 is extended by a cylindrical tubular portion 2a which, by means of bearings 9 and 10, is centred in, and rotates in, a fixed sleeve ll, which is mounted in an internal sleeve 12 forming an integral part of an oil-collecting casing 13.
  • the grooves a and b communicate, respectively, with the jack compartments A and B, as described in U.S. Specification No. 2,835,227.
  • the tubular portion 2a includes two borings 20 and 21 which open into the compartment A of the jack.
  • the central narrow part 20a of the boring 20 contains a solid piston 23 which has two pointed extensions 24A and 24B,
  • the boring 21 contains two pistons 32A and 32B separated by a spring 33.
  • the piston 32A is subjected directly to the pressure reigning in the compartment A.
  • the piston 32B bears against a stop 34 formed integrally with a plug 35 which also bears against the cover 30.
  • the stop member 34, 35 is disposed in an enlarged portion 21a of the boring 2I which, via a boring 36 formed in the wall of the tubular portion 2a, communicates with a part 20b of the boring 20 situated between the plug 29 and the valve seating 258.
  • the longitudinal boring 37 shown in chain lines, which connects with the boring 36, corresponds, as indicated by the arrow 38, with the interior of the tubular rod 6 for evacuating the jack compartment Bv
  • the arrangement of FIG. I functions as follows:
  • the balls of the valves are subjected to centrifugal force, which is capable of altering the function. It will be noticed, however, that these balls are in practice situated on the smallest possible radius of the rotating jack, having regard to the existence of the axial passage through the jack.
  • the balls may be made from a light metal, for example from oxidised anodic aluminium.
  • valve seatings 25A, 258, may be engaged simply in the corresponding borings, Under the effect of the pressure. they behave as valves and are not influenced by the movement.
  • FIGS. 2 to 9 has numerous analogies with the embodiment that has just been described and similar members carry the same reference numerals.
  • the non-return valves are of the slide valve type, each valve being movable to open position by an independent piston-operated push rod, Finally, the pistons for maintaining the pressure are arranged to increase this pressure.
  • FIG. 2 The principle of operation is illustrated by FIG. 2.
  • the non-return valves 41A and 41B are disposed, respectively, the non-return valves 41A and 41B and, due to the provision of the crossed branch connections 42A and 428, the placing under pressure of one of the two grooves opens the non-return valve associated with the other groove.
  • the pressure of the control oil, upstream of the non-return valves, is applied via the by-pass lines 47A and 478 to the annular surfaces 48A and 48B of the differential pistons.
  • the loss of oil may attain half a cubic centimetre, without falling below this control value, It is still more than a twentieth of a cubic centimetre for a pressure of five bars.
  • the differen tial pistons 45A and 45B are housed in shouldered axial borings 50A and 505. As shown in FIGS. 5 and 9, a direct connection of the groove a with the annular chamber defined in the boring 50A by the piston 45A, is obtained by a short radial boring 51 starting from the groove 0 which intersects an oblique boring 52 closed by a plug 53.
  • the pressure in the groove 0 acts directly on the head 56 of the valve 41A which, applied against its seat, obturates the communication with the chamber A through a conduit 57.
  • This conduit serves as a support for one end of a spring 58 of the valve, the conduit being retained by a spring ring 59.
  • the head of the hollow valve is thinned down and includes radial borings 60 for placing the oil supply in communication with the conduit 57.
  • the groove a is in direct communication with a cylinder 62 containing a piston 63B intended to force open the valve 418.
  • the latter is arranged, like the valve 41A, to place the groove b, via a radial opening 64, in connection with the tubular rod 6 which communicates with the compartment B.
  • the groove 1) is also in direct communication with the boring 505 in order to act on the annular area of the differential piston 458.
  • the groove h is placed in communication with a cylindrical space 69 which contains a piston provided with a pushrod 63A intended to act on the valve 41A.
  • transverse conduit 70 which connects the boring 508 with a boring 71 containing the valve 418 and the end of the tubular rod 6, the pressure ofthe compartment B is transmitted to the small section 44A of the piston 45A.
  • each of the grooves a and b is associated with three paths, one towards the said valve, the second towards the piston which forces open the other non-return valve, and the third which terminates at the annular chamber of the differential piston which compensates or amplifies the pressure, the small surface of this piston being in direct communication with the corresponding compartment of the jack.
  • the invention is applicable to the control of chucks of machine tools and especially of lathes having high speeds of rotation.
  • a hydraulic jack device comprising a rotary cylinder
  • conduit means including rotary joint means for connecting each of said compartments to a source of liquid under pressure, said conduit means including, between said rotary joint means and each compartment, a liquid flow-path provided with a pressure responsive nonreturn valve,
  • pressure operated piston means for forcibly opening a respective non-return valve in one flow path responsive to pressure in the other flow path
  • first duct means connecting said piston means with each flow path upstream of said non-return valves
  • each flow-path means defining a stepped cylindrical cavity comprising a first portion of small diameter and a second portion of large diameter forming an extension of said first portion,
  • second duct means connecting the end of said first portion remote from said second portion with the associated flow-path downstream of the corresponding said non-return valve
  • a differential piston in said cavity having two sections secured to one another and respectively cooperating with both cavity portions
  • third duct means connecting the annular space comprised between the junction of said portions and the two sections of the differential piston with the associated path upstream of the corresponding non-return valve.
  • a hydraulic jack device adapted for equipment of a lathe headstock wherein said cylinder with said piston mounted thereon is tubular, an axial tubular extension of said cylinder, said rotary joint means being arranged on said axial tubular exten sion of said cylinder, and wherein, in said tubular extension, said non-return valves and piston means are located in axial bores, and said cavities are axially bored in said tubular extension, and said flow-paths and duct means are drillings also pierced in said tubular extension.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Gripping On Spindles (AREA)
  • Actuator (AREA)
  • Fluid-Pressure Circuits (AREA)
US348598A 1972-04-11 1973-04-06 Rotary hydraulic jack device Expired - Lifetime US3892165A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7212621A FR2180425B1 (zh) 1972-04-11 1972-04-11

Publications (1)

Publication Number Publication Date
US3892165A true US3892165A (en) 1975-07-01

Family

ID=9096650

Family Applications (1)

Application Number Title Priority Date Filing Date
US348598A Expired - Lifetime US3892165A (en) 1972-04-11 1973-04-06 Rotary hydraulic jack device

Country Status (6)

Country Link
US (1) US3892165A (zh)
JP (1) JPS4916074A (zh)
DE (1) DE2318240A1 (zh)
FR (1) FR2180425B1 (zh)
GB (1) GB1424225A (zh)
IT (1) IT981790B (zh)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3972537A (en) * 1975-01-09 1976-08-03 The Warner & Swasey Company Chuck actuator assembly
US3986437A (en) * 1973-04-24 1976-10-19 La Precision Industrielle Double-acting rotary hydraulic jack
US4034958A (en) * 1974-06-14 1977-07-12 Messier Hispano Independent device for opening and closing rotary valves by remote control
US4249451A (en) * 1977-04-07 1981-02-10 La Precision Industrielle Rotary hydraulic jack device
US4349207A (en) * 1980-11-14 1982-09-14 Metrology Systems Corp. Fluid actuated chuck
US4380150A (en) * 1979-02-22 1983-04-19 Carlson John C Pump jack assembly for wells
US4630441A (en) * 1984-09-04 1986-12-23 The Boeing Company Electrohydraulic actuator for aircraft control surfaces
US4669362A (en) * 1983-11-04 1987-06-02 Kabushiki Kaisha Kitagawa Tekkosho Rotary fluid pressure cylinder device for operating chucks for machine tools
WO1987003941A1 (en) * 1985-12-23 1987-07-02 Sundstrand Corporation Rotating hydraulic cylinder actuator utilizing rotation generated centrifugal head for piston positioning
US4762050A (en) * 1985-10-23 1988-08-09 Aced S.A. Rotary hydraulic actuator
WO1989006580A1 (en) * 1988-01-19 1989-07-27 GEDIB Ingenieurbüro und Innovationsberatung GmbH Device for producing a clamping force for operating a power clamping device for rotating working spindles
US4941542A (en) * 1986-10-01 1990-07-17 Mazda Motor Corporation Automotive four wheel steering system
US20060249016A1 (en) * 2005-03-31 2006-11-09 Nabtesco Corporation Hydraulic circuit and its valve gear
WO2016029695A1 (zh) * 2014-08-26 2016-03-03 大连光洋科技集团有限公司 无动力空腔推拉器及其应用的夹紧器

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4747337A (en) * 1985-02-18 1988-05-31 Kitagawa Iron Works Co., Ltd. Rotary fluid cylinders for operating chucks
DE3642262A1 (de) * 1986-12-11 1988-06-23 Stromag Maschf Schaltkupplung

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2283961A (en) * 1938-06-09 1942-05-26 Bliss E W Co Pressure booster unit
US2359949A (en) * 1942-06-23 1944-10-10 Adel Prec Products Corp Hydraulic remote control system
US2599664A (en) * 1950-03-01 1952-06-10 Cushman Chuck Co Swivel connection for airoperated chucks
US2780065A (en) * 1955-07-20 1957-02-05 Letourneau Westinghouse Compan Closed hydraulic system
US2809612A (en) * 1956-11-28 1957-10-15 Whiton Machine Company Valve and cylinder construction for an air operated chuck
US3145662A (en) * 1960-09-06 1964-08-25 Eickmann Karl Device for damping vibrations, fluctuations of pressure and fluctuation of deliveryvolume or suction volume of rotary piston machines
US3213874A (en) * 1961-06-02 1965-10-26 Parker Hannifin Corp Pressure responsive flow control valve for directional control valve
US3369464A (en) * 1964-01-24 1968-02-20 Forkardt Paul Kg Method of and apparatus for actuating double-acting rotatable clamping means, especially for working spindles
US3641875A (en) * 1969-03-07 1972-02-15 Rohm Gmbh Werkzeug Und Maschin Omnidirectional pressurized hydraulic and pneumatic fluid-actuated piston-type power means for operating mechanisms, such as a chuck, by reciprocating linear movements, omnidirectionally, within any plane

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1215943A (fr) * 1957-11-29 1960-04-21 Adamovske Strojirny Np Dispositif de sécurité pour installations fonctionnant sous pression
CH471328A (de) * 1968-04-30 1969-04-15 Forkardt Paul Kg Vorrichtung zum Zuführen von Druckflüssigkeit zu einem umlaufenden, doppeltwirkenden Hydraulikzylinder

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2283961A (en) * 1938-06-09 1942-05-26 Bliss E W Co Pressure booster unit
US2359949A (en) * 1942-06-23 1944-10-10 Adel Prec Products Corp Hydraulic remote control system
US2599664A (en) * 1950-03-01 1952-06-10 Cushman Chuck Co Swivel connection for airoperated chucks
US2780065A (en) * 1955-07-20 1957-02-05 Letourneau Westinghouse Compan Closed hydraulic system
US2809612A (en) * 1956-11-28 1957-10-15 Whiton Machine Company Valve and cylinder construction for an air operated chuck
US3145662A (en) * 1960-09-06 1964-08-25 Eickmann Karl Device for damping vibrations, fluctuations of pressure and fluctuation of deliveryvolume or suction volume of rotary piston machines
US3213874A (en) * 1961-06-02 1965-10-26 Parker Hannifin Corp Pressure responsive flow control valve for directional control valve
US3369464A (en) * 1964-01-24 1968-02-20 Forkardt Paul Kg Method of and apparatus for actuating double-acting rotatable clamping means, especially for working spindles
US3641875A (en) * 1969-03-07 1972-02-15 Rohm Gmbh Werkzeug Und Maschin Omnidirectional pressurized hydraulic and pneumatic fluid-actuated piston-type power means for operating mechanisms, such as a chuck, by reciprocating linear movements, omnidirectionally, within any plane

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3986437A (en) * 1973-04-24 1976-10-19 La Precision Industrielle Double-acting rotary hydraulic jack
US4034958A (en) * 1974-06-14 1977-07-12 Messier Hispano Independent device for opening and closing rotary valves by remote control
US3972537A (en) * 1975-01-09 1976-08-03 The Warner & Swasey Company Chuck actuator assembly
US4249451A (en) * 1977-04-07 1981-02-10 La Precision Industrielle Rotary hydraulic jack device
US4380150A (en) * 1979-02-22 1983-04-19 Carlson John C Pump jack assembly for wells
US4349207A (en) * 1980-11-14 1982-09-14 Metrology Systems Corp. Fluid actuated chuck
US4669362A (en) * 1983-11-04 1987-06-02 Kabushiki Kaisha Kitagawa Tekkosho Rotary fluid pressure cylinder device for operating chucks for machine tools
US4630441A (en) * 1984-09-04 1986-12-23 The Boeing Company Electrohydraulic actuator for aircraft control surfaces
US4762050A (en) * 1985-10-23 1988-08-09 Aced S.A. Rotary hydraulic actuator
WO1987003941A1 (en) * 1985-12-23 1987-07-02 Sundstrand Corporation Rotating hydraulic cylinder actuator utilizing rotation generated centrifugal head for piston positioning
US4753071A (en) * 1985-12-23 1988-06-28 Sundstrand Corporation Self-powered rotating-cylinder type linear actuator utilizing rotation-generated centrifugal head for piston positioning
US4941542A (en) * 1986-10-01 1990-07-17 Mazda Motor Corporation Automotive four wheel steering system
WO1989006580A1 (en) * 1988-01-19 1989-07-27 GEDIB Ingenieurbüro und Innovationsberatung GmbH Device for producing a clamping force for operating a power clamping device for rotating working spindles
US20060249016A1 (en) * 2005-03-31 2006-11-09 Nabtesco Corporation Hydraulic circuit and its valve gear
US7263924B2 (en) * 2005-03-31 2007-09-04 Nabtesco Corporation Hydraulic circuit and its valve gear
WO2016029695A1 (zh) * 2014-08-26 2016-03-03 大连光洋科技集团有限公司 无动力空腔推拉器及其应用的夹紧器

Also Published As

Publication number Publication date
GB1424225A (en) 1976-02-11
FR2180425B1 (zh) 1974-08-30
IT981790B (it) 1974-10-10
JPS4916074A (zh) 1974-02-13
DE2318240A1 (de) 1973-10-25
FR2180425A1 (zh) 1973-11-30

Similar Documents

Publication Publication Date Title
US3892165A (en) Rotary hydraulic jack device
US3855902A (en) Cylinder piston unit for a power operated revolving chuck
US2886346A (en) Drill head with hydraulic thrust balancing means
US3168013A (en) Hydraulic systems
US4791841A (en) Chucking device
US5060957A (en) Power-operated chuck
US2577858A (en) High-speed rotating cylinder
US4149602A (en) Hydraulically-operated percussive device
US4723778A (en) Automatic lubricating system of power chuck
US3641875A (en) Omnidirectional pressurized hydraulic and pneumatic fluid-actuated piston-type power means for operating mechanisms, such as a chuck, by reciprocating linear movements, omnidirectionally, within any plane
US4249451A (en) Rotary hydraulic jack device
US4349207A (en) Fluid actuated chuck
US3924514A (en) Apparatus for actuating a work gripping device
US3439925A (en) Hydraulic cylinder
US3417672A (en) Rotary hydraulic cylinder
US4762050A (en) Rotary hydraulic actuator
US3988969A (en) Rotary hydraulic jack
US2910905A (en) Slidable tailstock
US3425322A (en) Hydraulic slide control
US2528442A (en) Power chuck
USRE23822E (en) Power feed mechanism
US3380350A (en) Rotating air cylinder utilizing air as air seal
US3685397A (en) Swivel fitting
US4332186A (en) Hydraulic actuator for lathe chuck
US2157892A (en) Transmission and control

Legal Events

Date Code Title Description
AS Assignment

Owner name: GAMET PRECISION S.A., ROUTE D EPEGARD 27110 LE NEU

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:LA PRECISION INDUSTRIELLE S.A., A CORP OF FRANCE;REEL/FRAME:004492/0057

Effective date: 19850122