Abstract: The power screwdriver comprises a functional part (11) with a housing (14) through which a shaft (17) passes. The shaft (17) is provided with a toothing (18), into which a ratchet lever of the functional part (11) engages. A splined shaft toothing (20) of the shaft (17) has an insertion recess (21) that changes into a cavity (22). The wall of the cavity (22) is provided with a torsion sensor (23) and forms a measuring section (25) that is located in the area of the shaft (17) covered by the housing (14). A torsion measurement is effected in the measuring section (25). Due to the measuring section (25) being located in the area of the shaft covered by the housing (14), the shaft (17) is relatively short whereby it may be used under tight spatial screwing conditions involving a low head height above the screw. The power wrench is additionally provided with an angle measuring device (33) whereby torque and angle of rotation can be simultaneously provided and can be used for controlling and recording.

Abstract: The power wrench comprises a housing (10) consisting of a head portion (11) and a driving portion (12). The driving portion (12) includes a cylinder bushing (21) which is introduced into the housing (10) through an opening (22) on the side facing away from the head portion (11). The cylinder bushing (21) with the piston (28) contained therein can easily be exchanged. With a lock connection, the piston rod (29) engages the pivotable lever (17) included in the head portion so that it can be pulled off by the lever (17).

Abstract: The power wrench comprises a housing (10) consisting of a head portion (11) and a drive portion (12). The drive portion (12) contains a cylinder sleeve (21) which is introduced into the housing (10) from the side facing away from the head portion (11). A pressure channel being connected to the hose connector (41) consists of a longitudinal bore (45) extending in the wall of the cylinder sleeve (21) to supply the high pressure required to the rearward cylinder chamber (36). Thereby, it is avoided that the housing (10), in the area of support, is additionally subject to hydraulic pressure. In case of bursting of the pressure duct, the cylinder sleeve (21) is still held together by the housing (10).

Abstract: The power wrench has a substantially T-shaped configuration and comprises a transversely extending housing (10) and a headpiece (11) extending centrally therefrom. The housing (10) comprises a working cylinder (17) and an additional cylinder (21). Both cylinders guide a unit (60) having at the one end a working piston (25) and at the other end an additional piston (29). The lever (41) of the headpiece (11) engages in a coupling member (27). The additional cylinder (21) drives the return stroke. Its area is substantially smaller than that of the working cylinder (17), so that the return movement does not require much hydraulic fluid. The headpiece (11) can easily be exchanged. Its lever (41) loosely engages in the coupling member (27) of the unit (60).

Abstract: A power wrench comprises a ring member for connection to the screw head to be rotated, the ring member being rotated with an engaging lever. The ratchet lever is driven by the piston rod of a piston. The piston has a convex circumferential surface so that it may be tilted within the cylinder in order to adapt to different orientations of the piston rod.

Abstract: The power wrench is provided with two pistons (38,41) arranged within each other. The pistons (38,41) abut against a pressure member (26) for pivoting a lever (18). The lever (18) is connected by an annular member (14) to the bolt head to be rotated. In a working stroke, the path of the first piston (38) is limited in that this piston impinges onto an abutment (46) while the second piston (41) moves on. The largest part of the working stroke is performed exclusively by the second piston (41) and thus is effected with low hydraulic throughput. When the force of the second piston (41) is not sufficient anymore, the working strokes are performed by both pistons (38,41) in common over the shorter piston path.

Abstract: The pressure-operated power wrench is provided with an annular member (14) rotatably supported within a headpiece (10). The annular member (14) can be coupled to the bolt to be rotated and is taken along in a moving direction by a ratchet lever (18). The lever (18) is actuated by a hydraulically moved piston (40). The piston (40) has a first piston face (45) and a second piston face (47) arranged coaxially thereto. When the load moment is small, only the first piston face (45) is pressurized. When this pressure exceeds a limit value, a back-check valve (57) is opened whereby also the second piston face (47) is pressurized. In the phase wherein rotation for tightening a bolt is still easy, only a small quantity of oil need be moved. Thus, power and heat losses are small. Further, the easy-rotating phase is abbreviated by fast reciprocation of the piston.

Abstract: The power wrench is provided with a coupling (14), switching dependent on the rotational moment and switching between a fast run mode and a load mode, when the rotational moment of the output exceeds a limit value. A distributing shaft (23) simulaneously drives two drive gears (26, 27). The output shaft (28) is pulled by a coupling member (32) that may be engaged to any one of said drive gears (26, 27). The coupling member (32) is prestressed by a spring (38) towards said first drive gear. At reaching the limit moment, the guiding member (40) shifts along the guide surface (39). This causes an axial movement of the coupling member (32) to disengage from said first drive gear (26) and to engage with said second drive gear (27).

Abstract: The power wrench is provided with a hydraulic cylinder unit (12) and a wrench head (10). The cylinder unit (12) is movable with an arm (11) of the wrench head along a female guiding track (15), which is substantially parallel to the axis (16) of the wrench head (10). This way, the wrench head (10) may be less wide than the cylinder unit (12) and the cylinder unit (12) can be set so as not to collide with obstacles near the screw head to be turned.

Abstract: The power wrench comprises a housing (10) with a rearward housing member (12) which forms a protection against bursting for the hydraulic cylinder (27) arranged within the housing member (12). Through a joint (38, 40) and self-aligning, the piston (35) acts upon the lever (18) which is supported coaxially to the ring (14). The lever (18) comprises a ratchet element (17) being supported at the lever (18) by a semisperical pressure member (20). The power wrench can be submitted to extremely high hydraulic pressures without a danger to the environment.

Abstract: The piston-cylinder unit (30') of a power wrench presses against the arm (16), by means of a ball and socket joint (44, 45), for swivelling the ring (11), which is connected secure against rotation to the wrench head to be turned. The piston (35) and the arm (16) have complementary spherical surfaces (40, 41) which press against each other. The dimensions of the spherical surfaces can be selected in dependence on the maximum power to be transmitted. The result is a uniform power distribution and a force-free adaptation of the movements of piston (35) and arm (16), without jamming and tilting.

Abstract: A power wrench operated with a pressure medium comprises a wrench head casing (10) which is engaged by a piston-cylinder unit (28,29). The other end of the piston-cylinder unit (28,29) is pressing against a support element (27) guided on a guideway (22) of the wrench head casing (10). The outer end (28) of the support element is applied to a stationary abutment. Upon rotating the wrench head (10) the ring (11) retaining the bolt or screw head is entrained by a ratchet (15) only in one sense of rotation, while the wrench head casing (10) is returned idly without entrainment of ring (11) in the other sense of rotation.

Abstract: The rotary tool contains a gear portion (16) whose input shaft (26) is driven by a hydraulic motor. The input shaft (26) is coupled with the output shaft (31) via an overload clutch (35,36,42) to ensure that with a low load, the transmission ratio is 1:1. With a higher load, the overload clutch automatically disengages so that the drive will be effected from the input shaft (26) via a double-stage sun-and-planet gear to the output shaft (31) which then is turning at a lower speed. Between the first stage (I GS) and the second stage (II GS) of the reduction gear, there is an overrunning clutch (52) which only couples with each other the two gear stages if the output shaft (31) turns more slowly than the input shaft (26).

Abstract: This power wrench includes a wrench head that rotatably supports a ring having a non-circular internal profile. A ratchet device moves the ring only in one direction of rotation with respect to the wrench head. The wrench head has an internal extension and a support element is coaxially pivotally attached to the wrench head. A piston cylinder unit, including a piston and a piston rod is provided. The first end of the piston cylinder unit is rigidly connected to the integral extension of the wrench head and the second end of the unit is in contact with the support element. The distance between the center of the wrench head and the first end of the piston cylinder unit is about the same as the distance between the center of the wrench head and the second end of the unit. One end of the piston rod is flexibly held at the piston and the other end is flexibly held at the support element.

Abstract: The screw assembly comprises a drive unit whose output shaft (14) can be connected with a button die to be applied to a screw head.To prevent the casing (10) of the drive unit from rotating, it is fitted with a retainer (24) which is placed against a solid abutment.The retainer (24) has a ring (23) enclosing the output shaft and being connected via a torsionally elastic element (16) with the casing (10).Torsional deformation of the torsionally elastic element (16) is used as a measure for the torque acting on the screw head. (FIG. 1).

Abstract: A wrench having a handle with an actuating lever arm pivoted for operation to rotate a nut engaging ring geometrically configured to accept a nut or bolt head. The nut engaging ring includes two tappets extending in the plane of rotation of the lever arm. A torque applied to the lever arm engages these tappets and thereby causes the nut engaging ring to rotate with increased force.

Abstract: This disclosure relates to a tool for rotating elements, such as nuts, bolts, screws or like fasteners, and includes a ring having ratchet teeth, the ring being driven by a lever, a pawl carried by the lever for engaging the ratchet teeth, a flexible tension-applying member in at least partial surrounding relationship to the ring, means for supporting the pawl, and the tension-applying member being disposed between the supporting means and the lever whereby upon movement of the lever in a first direction the pawl rotates the ring through the engagement of a tooth of the ring and the tension-applying member deforms slightly to frictionally grip the ring.

Abstract: A power wrench having at least a partially annular drive head connected at first and second pivots through a first of a pair of telescopic members and to a third member, respectively, the third member being connected by a third pivot to the second member, and upon a relative linear telescopic motion of the first and second members, the drive head is rotated through a predetermined arc under the control of the third member.

Abstract: Methodwise this disclosure relates to the manufacture of workpieces having polygonal inner or outer contours based upon radii of predetermined inner and outer circles with n being the number of angles of the desired polygon, the method including the steps of rotating a workpiece about its axis, moving the tool along an ellipsoidal path while in contact with the rotating workpiece with tool travel along the ellipsoidal path having velocity varying generally sinusoidally as a function of tool location, said ellipsoidal paht is radially offset from the workpiece axis of rotation and its width generally corresponds to the difference between said inner and outer radii, and rotating the workpiece about its axis for a duration of time longer than the duration of movement of the tool along the ellipsoidal path by said factor n.