Abstract: A check valve (14) with a valve opening actuator and a bypass passage (16) are disposed in parallel in a pressurized oil supply/discharge passage (3) connected in communication with a hydraulic actuation chamber (2). A residual pressure holding valve (17) and a flow restrictor (21) are disposed in series in the bypass passage (16). The supply/discharge passage (3) and a discharge passage (7) are connected in communication by a pressure compensation valve (12). While the valve (17) is adapted to be moved to a valve closing position by means of pressure supplied at a check valve inlet (14a) and a residual pressure holding spring (19), it is adapted to be moved to its valve opening position by means of pressure supplied at a check valve outlet (14b). The valve (17) includes a valve member (38) resiliently urged to a valve seat (40) by means of a spring (19).

Abstract: In a hydraulic cylinder apparatus of a type actuated by a booster, a plunger chamber (39) of a booster (32) is connected in communication with an extension cylinder chamber (35) of a hydraulic cylinder (30). An annular oil make-up chamber (48) is disposed outside an outer peripheral surface of the cylinder chamber (35). The oil make-up chamber (48) is connected in communication with the plunger chamber (39) and an electromagnetically opened and closed type shutoff valve (49) is interposed between both said chambers (39) (48).

Abstract: In a check valve with a valve opening device, a check valve member (32) inserted into a check valve chamber (21) formed in a valve box (20) is resiliently urged for valve closing by means of a check spring (33) as well as the check valve member (32) is manipulated for valve opening through a manipulation lever (45), an actuator shaft (43) and a valve opening member (36) in order. The valve opening member (36) is adapted to be held at a valve opening position (F) by means of a valve opened state holding means (38). The valve opened state holding means (38) is arranged in both the valve opening member (36) and the valve box (20). A manipulation lever return spring (46) is disposed in a manipulation force transmitting system from the manipulation lever (45) to the valve box (20) through the actuator shaft (43).

Abstract: In a hydraulic clamp with a direct operated clamping-member, a piston (13) is so inserted into a cylinder bore (11) formed in an upper portion of a housing (4) as to be slidable in the vertical direction. A peripheral wall (11a) of the cylinder bore (11) is projected downwardly and fixedly secured to a lower portion of the housing (4). An opening (12) is so formed in the lower portion of the peripheral wall (11a) as to face a fixed object (2) such as a metal mould. A clamping actuation oil chamber (15) is formed above the piston (13). A spring accommodation bore (21) is formed upwardly from below in a clamping-member (5) which protrudes downwardly from the piston (13), and an unclamping spring (23) is inserted into the spring accommodation bore (21).

Abstract: In a hydraulic clamp with a direct operated rotary clamping-member, a clamping-member (6) is fixedly secured to the lower portion of a clamp rod (22) adapted to be actuated by a hydraulic cylinder (12). When the hydraulic cylinder (12) is actuated for clamping, the clamping-member (6) is upward straightly actuated and changed over to a clamping condition (C) after being rotated to a clamping preparation condition (B) from an unclamping condition (A), through a rotary actuation device (13) and the clamp rod (22). The clamp rod (22) is interlockingly connected to a rotary member (27) of the rotary actuation device (13) in the rotatably actuated and slidably lowered state with respect to the rotary member (27).

Abstract: An actuation member (B) supported by a housing (A) is actuated for clamping upwardly by means of a spring force and actuated downwardly for unclamping by means of an actuation means (D). A piston (11) is inserted into a cylinder (10) fixedly secured to the upper portion of the housing (A), and a liquid sealing chamber (12) is formed below the piston (11). The piston (11) is fixedly secured to the actuation member (B). When the actuation member (B) is held in the clamped condition, a liquid sealing valve (15) is closed so as to seal an oil (L) within the liquid sealing chamber (12). Whereby, in case that a pulling down force larger than the clamping spring force is imposed to the actuation member (B), a pressure generated within the liquid sealing chamber (12) serves to prevent the piston (11) from lowering, against the pulling down force.

Abstract: In a three way valve assembly with a pressure compensating valve, a three way valve (2) is adapted to selectively communicate a work port (A) to a pressure supply port (S) and to a pressure discharge port (T). A pressure compensating valve (3) is adapted to release a pressure abnormally raised at a very slow speed within the work port (A) to the pressure discharge port (T). A first housing (10) of the three way valve (2) is fixedly secured between left and right end plates (4) (5) by means of assembly bolts (6) (7). A second housing (57) of the pressure compensating valve (3) is fixedly secured to one end surface (10c) of upper, lower, front and back end surfaces of the first housing (10) by means of a fixing means (67).

Abstract: In a roller conveyor device, a plurality of rollers (7) are rotatably supported by left and right support walls (16)(16) which extend in the fore and back direction and scrapers (21) are provided on the fore and the back sides of each roller (7) respectively between both the support walls (16)(16). The scraper (21) comprises an upper wall (24a), a left and a right side walls (22b)(24b) and scraper portions (25) projected integrally in the fore and back direction from the upper wall (24a) and adapted to be kept in contact with an upper portion of an outer peripheral surface of each roller (7). Spherical shelly convexed portions (27)(27) are provided in each said side wall (24b), and through-holes (29)(29) for engaging with the respective spherical shelly convexed portions (27)(27) are opened in the inside surfaces of the respective support walls (16)(16).

Abstract: A hydraulic clamp includes an inclined direct operated clamping member, a cylinder bore formed in a housing in such an inclined manner as forwardly descending, a piston inserted into the cylinder bore, a clamping actuation hydraulic chamber formed behind the piston within the cylinder bore, and a clamping member forwardly protruding from the upper portion of the front end of the piston. A spring accommodation recess is formed so as to extend rearward from the piston front end, and a spring retainer is supported by the housing in front of the piston. An unclamping spring is installed between the spring retainer and a spring retaining seat formed in the rearward most portion of the spring accommodation recess.

Abstract: An upper portion (3a) of an upper-die (3) is fixedly secured to a lower portion (2) of a ram (1) extending horizontally by way of a first clamping member (5) and a second clamping member (6) therebetween from both the fore side and the back side. The second clamping means (6) comprises a plurality of press plates (8)(8) arranged side by side in the horizontal direction. An opperating oil chamber (20) of a hydraulic cylinder (19) provided in each press plate (8) is connected in communication to a pressurized oil outlet port (42) and to a pressurized oil inlet port (41) both of which are opened in laterally opposed end surfaces (8b)(8a) of the press plate (8) respectively. The pressurized oil outlet port (42) and the pressurized oil inlet port (41) facing each other of the adjacent press plates (8)( 8) are connected in communication to each other by means of an interconnection pipe ( 23).

Abstract: In an apparatus and a method for replacing a working-object of a processing machine, there are provided a working-object replacing support (6), a working-object moving passage (12) and a push/pull drive means (18) for the working-objects (5a)(5b).The push/pull drive means (18) is provided with a push/pull drive device (19), a push/pull engaging member pedestal (20), a push/pull transmission member (21), a guide rail (22) and a push/pull engaging member (23).An engaging portion (59) of the engaging member (23) is adapted to be shifted to a position lower than height positions of lower surfaces of engaged portions (25)(26) of the working-objects (5a)(5b) under the changed over condition to the disengagement position (Y) and at least to face upward so as to be engaged with the engaged portions (25)(26) from below under the changed over condition to the engagement position (X).

Abstract: An apparatus for driving a piston by fluid pressure in which a piston (8) is reciprocated upward and downward by supplying and discharging pressure fluid to and from an actuation chamber (9) disposed in a cylinder (7) through a pilot valve (18) and a fluid pressure supply-discharge valve (13). Above a supply-discharge valve member (30) of the supply-discharge valve (13) there is provided a cylinder chamber (70a), into which a pilot valve casing (71) is inserted so as to hermetically slide up and down. The fluid pressure in the discharge actuation chamber (35) disposed above the supply-discharge valve member (30) allows the pilot valve casing (71) to ascend against a return spring (73).

Abstract: A control valve assembly for a pressurized oil has a valve chamber (4) within which a pressure supply valve seat (15), a first chamber (11), a short-circuit prevention valve seat (17), a second chamber (12) and a return valve seat (16) are arranged in order. A check valve member (19) inserted into the first chamber (11) is adapted to be resiliently urged to the pressure supply valve seat (15) for valve closing by means of a valve closing spring (19) through a resilient sealing member (21). A return valve member (22) and a short-circuit prevention valve member (23) are inserted into the second chamber (12) in series. The return valve member (22) is adapted to be resiliently urged to the return valve seat (16) for valve closing by means of another valve closing spring (30).

Abstract: A first coupling (51) and a second coupling (52) composing a quick-acting coupling (26) are respectively provided with check valve bodies (54)(154) and non-spill valve bodies (55)(155). When both the couplings (51)(52) are manipulated for the disconnection thereof, a leak of liquid is adapted to be prevented by means of the respective check valve bodies (54)(154) as well as a spill of liquid is adapted to be prevented by means of the non-spill valve bodies (55)(155). The respective non-spill valve bodies (55)(155) are fitted slidably inside respective non-spill valve port surfaces (71)(171) so as to carry out a liquid sealing respectively. Further, at the time of disconnecting manipulation of the coupling (26), a volume of the liquid phase portion within a non-spill valve casing chamber (63) is adapted to be increased by the movement of a non-spill valve casing (56) in which the first non-spill valve body (55) is fitted.

Abstract: A first coupling (51) and a second coupling (52) composing a quick-acting coupling (26) are respectively provided with check valve bodies (54)(154) and non-spill valve bodies (55)(155). When both the couplings (51)(52) are manipulated for the disconnection thereof, a leak of liquid is adapted to be prevented by means of the respective check valve bodies (54)(154) as well as a spill of liquid is adapted to be prevented by means of the non-spill valve bodies (55)(155). The respective non-spill valve bodies (55)(155) are fitted slidably inside respective non-spill valve port surfaces (71)(171) so as to carry out a liquid sealing respectively. Further, at the time of disconnecting manipulation of the coupling (26), a volume of the liquid phase portion within a non-spill valve casing chamber (63) is adapted to be increased by the movement of a non-spill valve casing (56) in which the first non-spill valve body (55) is fitted.

Abstract: A hydraulic clamp, which actuates a clamping means by a hydraulic pressure of a hydraulic cylinder, has a clamping actuation oil chamber, a piston and the clamping means arranged in a cylinder body of the hydraulic cylinder in this order in the axial direction of the hydraulic cylinder. The clamping means is adapted to be shifted expansively and contractively between advanced position clamping and a retracted position (unclamping) which are at different distances from the axis of the hydraulic cylinder. The clamping means is adapted to be advanced from the retracted position to the advanced position in an early stage of the application of a hydraulic actuation force in the clamping actuation oil chamber, by which the piston is hydraulically actuated, and the clamping means is adapted to be actuated for clamping by a latter stage of the hydraulic pressure in the clamping actuation oil chamber.

Abstract: In a hydraulic clamp adapted to fixedly secure an object such as a die, a workpiece and the like strongly to a machine tool such as an injection molding machine, a press machine and the like by means of multiplication action of a wedge,a drive chamber is formed in a clamp housing with its front end open and a clamp arm is inserted in the drive chamber to be vertically pivotable,a driving wedge is inserted between a wedge retaining surface defining an upper part of the drive chamber and a driven portion formed at a top of the clamp arm from behind and adapted to be moved longitudinally reciprocatively by means of a hydraulic cylinder, anda sliding shuttle member is interposed between the sliding contact surfaces of the driving wedge and of at least one of the wedge retaining surface and the driven portion to be slidable in a forward and backward direction within a given range.

Abstract: A cylinder type hydraulic clamp having a clamping mechanism is adapted to be actuated by means of a hydraulic cylinder, and has a piston rod projected through the cylinder body of the hydraulic cylinder and is equipped at its leading end portion with the clamping means. The clamping means is arranged concentrically with the piston rod and is adapted to be resiliently urged by means of a contraction spring toward its contracted position to be pushed by means of an expansion slant cam toward its expanded position. At the time of the clamping actuation, when the clamping means is hydraulically actuated toward the cylinder body through the piston and the piston rod, the clamping means is first expanded diametrically by means of the expansion slant cam against the resilient force of the contraction spring and then a member to be clamped is fixedly pressed between the cylinder body and the clamping means expanded as mentioned above.

Abstract: A pneumatic-hydraulic booster type driving device for the cushion-knockout mechanism associated with the slide of a press-machine serves to stably hold down a work plate such as a printed board and the like while performing a cushion operation at the time of a pressing stroke and serves to knock out the work plate after the pressing stroke in the press-machine. In the driving device, a pneumatic-hydraulic booster is connected through a pressure oil supply and discharge means to a hydraulic actuation chamber of a cushion cylinder provided in the slide of the press-machine, and the pressure oil supply and discharge means comprises a valve chamber within a valve casing and a knockout actuator which is fixedly secured to the valve casing so as to perform the valve opening operation of the valve unit.

Abstract: In a plunger pump system of a quick pressure-rise type which is utilized for increasing the pressure of a working fluid to be supplied quickly to a hydraulic actuator, such as an oil hydraulic cylinder, both a high pressure plunger pump and a quick-charging pump are connected interlockingly to one prime mover so as to be driven synchronously. During a low pressure range of operation, a large amount of working fluid delivered from a quick-charging plunger chamber is adapted to be supplied to the hydraulic actuator through a high pressure plunger chamber. On the other hand, during a high pressure range of operation, a small amount of high pressure working fluid is adapted to be delivered from the high pressure plunger chamber to the hydraulic actuator.