Abstract: A hand tool for expanding hollow bodies contains a casing (2) having a laterally extending first hand lever (3). A second hand lever, (7) which consists of steel and is joined to the casing so as to pivot on a shaft (5), bears a pinion sector (6) surrounding the shaft (5). The two hand levers (3, 7) form a pliers In the casing (2) a bore is disposed for guiding a rack consisting of steel, one end of which cooperates within the bore with the pinion sector (6) such that an expansion wedge can be displaced outwardly by a closing movement of the two hand levers (3, 7). The casing has means by which an expansion head with radially moving expander jaws can be placed coaxially onto the outwardly tapered end of the spreading wedge. To reduce both the weight and the force required for operation, the casing (2) and its hand lever (3) consist of a light material from the plastic and light metal group. The casing (2) thus forms together with the rack a low-friction combination of light material and steel.

Abstract: A hand tool for expanding hollow bodies contains a casing (2) having a laterally extending first hand lever (3). A second hand lever, (7) which consists of steel and is joined to the casing so as to pivot on a shaft (5), bears a pinion sector (6) surrounding the shaft (5). The two hand levers (3, 7) form a pliers In the casing (2) a bore is disposed for guiding a rack consisting of steel, one end of which cooperates within the bore with the pinion sector (6) such that an expansion wedge can be displaced outwardly by a closing movement of the two hand levers (3, 7). The casing has means by which an expansion head with radially moving expander jaws can be placed coaxially onto the outwardly tapered end of the spreading wedge. To reduce both the weight and the force required for operation, the casing (2) and its hand lever (3) consist of a light material from the plastic and light metal group. The casing (2) thus forms together with the rack a low-friction combination of light material and steel.

Abstract: In a chuck for the rotary machining of workpieces (15), having a hollow shaft possessing a hollow shaft axis and jaws (13) which can be turned about axially parallel pivot pins (12) and which are configured as two-armed levers whose one end (13b) can be applied with gripping surfaces (13c) to the workpieces (15) and whose other end (13a) can be turned about the pivot pins (12) by means of a driven ring gear (8) coaxial with the hollow shaft axis (A-A), which can be rotated to a limited extent about the latter, a braking device (22) is associated with the hollow shaft (9). In order to reduce construction costs and permit a uniform increase of force by the operating thrust in both directions of rotation, the jaws (13) are in mirror-image symmetry with their own planes of symmetry running through the axes of the pivot pins (12), and furthermore, the jaws (13) can be swung to both sides according to the direction of rotation of the ring gear (8), with respect to a radial line passing through these axes.