Abstract: A housing (3) has an upper end wall (3a) which supports an upper slide portion (11) of a clamp rod (5) vertically movably. The housing (3) has a lower end wall (3b), a support cylinder (13) of which supports a lower slide portion (12) of the rod (5) vertically movably. The rod (5) is provided with an input portion (14) between the upper slide portion (11) and the lower slide portion (12). A clamp spring (20) connected to the input portion (14) drives the rod (5) downwards for clamping. The lower slide portion (12) has an outer periphery provided with a helical rotary groove (27) and a straight groove (28) which is in upward continuity with the rotary groove (27). A ball (29) engages with the rotary groove (27) and the straight groove (28). The ball (29) is supported by an inner wall (13a) of the support cylinder (13).

Abstract: A first piston (22) of a first locking cylinder (20) descends when a pressure of compressed air in an actuation chamber (23) has exceeded a pressure for locking commencement (P1) and ascends by a first spring (24) when the pressure of the compressed air has decreased to a pressure for releasing commencement (P2). A second advancing and retreating cylinder (32) comprises an inlet chamber (41) and an outlet chamber (45) formed below and above a second piston (35), respectively, and a second spring (46). The actuation chamber (23) communicates with the outside air through the outlet chamber (45). A restricting passage (37) is provided in a route between the actuation chamber (23) and the outside air. The actuation chamber (23) communicates with one of the inlet chamber (41) and the outlet chamber (45) through a communication hole (62).

Abstract: A work pallet (3) is opened to provide a circular positioning hole (5). A plug member (12) is inserted into the positioning hole (5) and projects from a base plate (2). The plug member (12) is provided with a slant outer surface (13) which narrows upwards. An intermediate member (15) in the shape of a thin-walled cylinder is arranged outside the plug member (12). The intermediate member (15) is provided with a straight outer surface (16) which is fitted into the positioning hole (5) and with a slant inner surface (17) which opposes to the slant outer surface (13) of the plug member (12). A coned disk spring (34) moves down the intermediate member (15) for locking through a pull member (21).

Abstract: A clamp rod (5) is vertically movably inserted into a housing (3). The housing (3) has a lower end wall (3b) formed with a detecting hole (58) substantially concentrically with an axis of the clamp rod (5). The detecting hole (58) has a peripheral surface opened to provide at least one inlet hole (71, 72) for supplying compressed air. A detecting member (62) is vertically movably fitted into the detecting hole (58). The detecting member (62) has an outer peripheral surface provided with a closing surface (68) which closes an opening portion (71a, 72a) of the inlet hole (71, 72) and with a recess (69) which communicates the opening portion (71a, 72a) with the outside air. The clamp rod (5) has a downwardly oriented projection (5a). The projection (5a) is connected to the detecting member (62) so that it can make a relative movement radially.

Abstract: A housing (3) has an upper end wall (3a) and a lower end wall (3b) which support an upper slide portion (11) and a lower slide portion (12) of a clamp rod (5) vertically movably, respectively. The rod (5) is moved downwards for clamping through a clamp spring (20). The lower slide portion (12) has an outer periphery provided with guide grooves (26), each of which comprises a helical rotary groove (27) and a straight groove (28), peripherally in plural number. Engaging balls (29) which are fitted into the respective guide grooves (26) are rotatably supported by through holes (31) provided in an upper portion of the lower end wall (3b). A sleeve (35) is externally fitted over the engaging balls (29) rotatably around an axis.

Abstract: A clamp rod (5) is inserted into a housing (3) rotatably around an axis and movably downwards for clamping. The clamp rod (5) has an outer peripheral portion formed with three guide grooves (26) which are arranged peripherally at substantially the same spacing. An engaging ball (29) which is fitted into every guide groove (26) is supported by a lower end wall (3b) of the housing (3). Each of the guide grooves (26) comprises a rotary groove (27) and a straight groove (28) which is in upward continuity with the rotary groove (27). The rotary grooves (27) as well as the straight grooves (28) are arranged in parallel with one another. A partition wall between the adjacent guide grooves (26), (26) has a minimum thickness (T) set to a value smaller than a diameter (D) of the engaging ball (29).

Abstract: When supplying pressurized oil from a first port (51) to a second port (78), first, a pallet (2) is lowered to a table (1). And a first stop member (45) of a socket (21) is brought into butting contact with a second stop member (67) of a plug (22), thereby forming a contact gap (B) between the second stop member (67) and a check member (72) within a check valve chamber (70) of the plug (22). Next, the pallet (2) is fixed to the table (1) by a locking device (3). Subsequently, the pressurized oil at the first port (51) is supplied to the second port (78) via the check valve chamber (70) and thereafter is discharged to an exterior area.

Abstract: A housing (3) has an upper end wall (3a) and a lower end wall (3b) which support an upper slide portion (11) and a lower slide portion (12) of a clamp rod (5) vertically movably, respectively. The rod (5) is moved downwards for clamping through a clamp spring (20). The lower slide portion (12) has an outer periphery provided with guide grooves (26), each of which comprises a helical rotary groove (27) and a straight groove (28), peripherally in plural number. Engaging balls (29) which are fitted into the respective guide grooves (26) are rotatably supported by through holes (31) provided in an upper portion of the lower end wall (3b). A sleeve (35) is externally fitted over the engaging balls (29) rotatably around an axis.

Abstract: A housing (4) has a cylinder bore (10) into which an annular hydraulic piston (11) is inserted vertically movably. The piston (11) has a tubular bore (11a) into which a driven rod (6) is inserted. The driven rod (6) is provided with an input portion (6a), around which a plurality of transmission members (15) are arranged peripherally side by side. The transmission members (15) swing to a disengaging position (Y) through a push member (30) by a lowering spring (31). When clamping, the piston (11) is driven upwards. Then, first, a slant cam (27) swings the transmission members (15) to an engageable position (X), thereby enabling engaging portions (17) to face the input portion (6a). Next, the piston (11) upwardly drives the input portion (6a) through the engaging portions (17).

Abstract: A work pallet (3) is opened to provide a circular positioning hole (5). A plug member (12) is inserted into the positioning hole (5) and projects from a base plate (2). The plug member (12) is provided with a slant outer surface (13) which narrows upwards. An intermediate member (15) in the shape of a thin-walled cylinder is arranged outside the plug member (12). The intermediate member (15) is provided with a straight outer surface (16) which is fitted into the positioning hole (5) and with a slant inner surface (17) which opposes to the slant outer surface (13) of the plug member (12). A coned disk spring (34) moves down the intermediate member (15) for locking through a pull member (21).

Abstract: A first piston (22) of a first locking cylinder (20) descends when a pressure of compressed air in an actuation chamber (23) has exceeded a pressure for locking commencement (P1) and ascends by a first spring (24) when the pressure of the compressed air has decreased to a pressure for releasing commencement (P2). A second advancing and retreating cylinder (32) comprises an inlet chamber (41) and an outlet chamber (45) formed below and above a second piston (35), respectively, and a second spring (46). The actuation chamber (23) communicates with the outside air through the outlet chamber (45). A restricting passage (37) is provided in a route between the actuation chamber (23) and the outside air. The actuation chamber (23) communicates with one of the inlet chamber (41) and the outlet chamber (45) through a communication hole (62).

Abstract: A clamp rod (5) is vertically movably inserted into a housing (3). The housing (3) has a lower end wall (3b) formed with a detecting hole (58) substantially concentrically with an axis of the clamp rod (5). The detecting hole (58) has a peripheral surface opened to provide at least one inlet hole (71, 72) for supplying compressed air. A detecting member (62) is vertically movably fitted into the detecting hole (58). The detecting member (62) has an outer peripheral surface provided with a closing surface (68) which closes an opening portion (71a, 72a) of the inlet hole (71, 72) and with a recess (69) which communicates the opening portion (71a, 72a) with the outside air. The clamp rod (5) has a downwardly oriented projection (5a). The projection (5a) is connected to the detecting member (62) so that it can make a relative movement radially.

Abstract: A work pallet (3) has an under surface opened to provide a positioning hole (12). The positioning hole (12) has an upper wall which supports a pull rod (13) diametrically movably. A clamp pallet (2) projects an annular plug portion (21), onto which a shuttle member (23) is externally fitted. The shuttle member (23) makes a tapering engagement with the positioning hole (12). The plug portion (21) has a cylindrical hole (21a), into which a transmission sleeve (31) is inserted. The transmission sleeve (31) supports an engaging ball (34), which engages with an engaged portion (13b) of the pull rod (13). Defined between the cylindrical hole (21a) and an outer peripheral surface (31b) of the transmission sleeve (31) is a flow passage (43) through which cleaning compressed air passes.

Abstract: A socket (A) includes a first flow passage (4) which is provided with a first closure member (14) and a first check member (32). And a plug (B) includes a second flow passage (54) which is provided with a second closure ember (64) and a second check member (82). The second check member (82) comprises a larger-diameter member (86) and a smaller-diameter member (88). A first cylindrical filter (20) is arranged on an outer periphery of the first closure member (14). A second cylindrical filter (37) is arranged on an outer periphery of the first check member (32). A third cylindrical filter (70) is arranged on an outer periphery of the second closure member (64). Each of the cylindrical filters (20), (37) and (70) comprises an inner perforated sheet (41), a screen (42) and an outer perforated sheet (43) arranged in the mentioned order from an interior area.

Abstract: A clamp rod (5) is inserted into a housing (3) rotatably around an axis and movably downwards for clamping. The clamp rod (5) has an outer peripheral portion formed with three guide grooves (26) which are arranged peripherally at substantially the same spacing. An engaging ball (29) which is fitted into every guide groove (26) is supported by a lower end wall (3b) of the housing (3). Each of the guide grooves (26) comprises a rotary groove (27) and a straight groove (28) which is in upward continuity with the rotary groove (27). The rotary grooves (27) as well as the straight grooves (28) are arranged in parallel with one another. A partition wall between the adjacent guide grooves (26), (26) has a minimum thickness (T) set to a value smaller than a diameter (D) of the engaging ball (29).

Abstract: A housing (3) has an upper end wall (3a) which supports an upper slide portion (11) of a clamp rod (5) vertically movably. The housing (3) has a lower end wall (3b), a support cylinder (13) of which supports a lower slide portion (12) of the rod (5) vertically movably. The rod (5) is provided with an input portion (14) between the upper slide portion (11) and the lower slide portion (12). A clamp spring (20) connected to the input portion (14) drives the rod (5) downwards for clamping. The lower slide portion (12) has an outer periphery provided with a helical rotary groove (27) and a straight groove (28) which is in upward continuity with the rotary groove (27). A ball (29) engages with the rotary groove (27) and the straight groove (28). The ball (29) is supported by an inner wall (13a) of the support cylinder (13).

Abstract: Two positioning devices (4, 5) are horizontally spaced apart from two clamping devices (6, 6) at a predetermined interval. Each of the positioning devices (4, 5) includes a positioning hole (23) provided by opening a work pallet (2), a plug portion (27) projecting from a clamp pallet (1), and an intermediate member (30) vertically movably supported by the plug portion (27). The intermediate member (30) is urged upwards by a coned disk spring (31) and has a tapered surface (33) which makes a tapering engagement with the positioning hole (23). The clamping device (6) fixes the work pallet (2) to the clamp pallet (1).

Abstract: When supplying pressurized oil from a first port (51) to a second port (78), first, a pallet (2) is lowered to a table (1). And a first stop member (45) of a socket (21) is brought into butting contact with a second stop member (67) of a plug (22), thereby forming a contact gap (B) between the second stop member (67) and a check member (72) within a check valve chamber (70) of the plug (22). Next, the pallet (2) is fixed to the table (1) by a locking device (3). Subsequently, the pressurized oil at the first port (51) is supplied to the second port (78) via the check valve chamber (70) and thereafter is discharged to an exterior area.

Abstract: When obtaining load displaying calibration data, first, a reference die height position (a) where a load (F) of a mechanical press (1) comes to minimum load value (Fa) is sought as well as a reference die height position (f) where the load (F) comes to maximum load value (Ff). Then a plurality of intermediate die height positions (b . . . e) are selected between these reference die height positions (a) and (f). Subsequently, a load is imposed on the mechanical press (1) at each of the die height positions (a . . . f) and a pressure sensor (33) senses peak oil pressures (Pa . . . Pf) corresponding to the respective die height positions (a . . . f). Thereafter, relative relationships between load values (Fa . . . Ff) corresponding to the die height positions (a . . . f) and the peak oil pressures (Pa . . . Pf) are obtained as a characteristic curve (B).

Abstract: A clamp pallet (2) is fixed to a table (1) of a machining center. A work pallet (3) has a positioning hole (12) and an engaging hole (13) formed in order from a lower side. A plug portion (21) projects upwards from the clamp pallet (2). A shuttle member (23) is vertically movably fitted onto the plug portion (21). A coned disc spring (24) urges the shuttle member (23) upwards. The shuttle member (23) has a tapered surface (28) with which the positioning hole (12) makes a tapering engagement. A pull rod (31) is inserted into the plug portion (21). The pull rod (31) pushes engaging balls (34) to the engaging hole (13), thereby driving the work pallet (3) downwards.