Abstract: The safety coupling comprises a housing (12) made up of a housing capsule (13) and a screwed-on housing cover (14). The torque is transmitted from the input shaft (10) via coupling disks (17, 18) to the output shaft (19). The first coupling disk (17) comprises rollers (23) rolling on a contoured coupling track (25) of the second coupling disk. The coupling track (25) is configured such that the rollers (23) are in exact line contact with the coupling track (25) over their length so that each roller (23) provides full support. Further, a locking device (33) is provided by means of which the turning position, to which the housing cover (14) has been adjusted for determinating the trip moment, can be locked.

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).