Clamping device
AssigneeSitema, Gesellschaft fur Sicherheitstechnik and Maschinenbau mbH
InventorsAdolf Rastetter, Erich Schmalenbach
Life of this patent
Estimating the term…
Abstract
A clamping device includes three clamping jaws guided at an angle in a hong for engaging an axially displaceable load-bearing rod. Reliable clamping is obtained without alteration of the setting position reached. This is achieved by providing a servo-piston in the housing, which piston is displaceable in both directions by servo-force and is directly connected to the clamping jaws. The frictional force between the rod and the bearing faces of the clamping jaws as well as between the guide faces of the clamping jaws and their associated guide tracks in the housing, as well as the angle of inclination of the guide tracks are such that, in operation, self-locking occurs. The clamping action of the clamping jaws may be released only by moving the servo piston.
Claims12
A device for clamping an axially displaceable load-bearing rod, said device comprising:
- a housing positioned with the rod extending therethrough, said housing having therein a plurality of planar guide tracks inclined relative to the axis of the rod;
- a plurality of clamping jaws spaced around the rod, each said clamping jaw being displaceable within said housing along a respective said guide track;
- a single annular servo-piston positioned within said housing surrrounding the rod and directly operating said clamping jaws;
- first means operable for moving said servo-piston and hence said clamping jaws in a first axial direction with respect to said housing such that said clamping jaws are drawn along their respective said inclined guide tracks toward the rod into clamping engagement therewith, the frictional force between the rod and the bearing faces of said clamping jaws, the frictional force between the guide faces of said clamping jaws and their said respective guide tracks and the angles of inclination of said guide tracks being such that, upon clamping of said clamping jaws against the rod, self-locking occurs;
- and
- servo second means, operable separately of said first means, for moving said servo-piston and hence said clamping jaws with respect to said housing in a second axial direction opposite to said first axial direction, and thereby to release said clamping jaws from the rod.
Dependencies are inferred from the claim text.