US 4,902,025 AGranted

Self-clamping or self-tightening chuck

AssigneeJoseph Albrecht, Bohrfutterfabrik GmbH & Co.

InventorArno W. Zimdars

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Abstract

To provide for an axially short self-tightening chuck, a spiral spring (22) is located inside the chuck to couple together a cylindrical surface (24) formed on the chuck spindle, for example on an extending flange (17) thereof and a cylindrical surface (25) on an axial extension (16) of a holding sleeve which retains the chucking mechanism, including clamping jaws (9) and the like. An operating ring (23) is engageable with an end portion of the spring. The spring has a direction of winding which, with a given direction of rotation of the tool, tightens the spring about the axially adjacent surfaces (24, 25) on the chuck body and the holding sleeve, so that they will rotate together, and, even under conditions of vibrations or sudden stopping, not loosen, since relative reverse rotation is inhibited by frictional engagement of the spiral spring between the parts. To release the chuck, an operating ring (23) is engageable with an end portion (27) of the spring, so that the spring can be mechanically released from the frictional engagement with the adjacent surfaces.

Claims13

Dependent claims

Self-clamping or self-tightening chuck having

an at least partly cylindrical base body (1);
a back-up spindle means (8, 11) coaxially secured to the base body;
a plurality of clamping or holding jaws (9) abutting against the terminal end of the spindle means and coupled thereto for rotational movement therewith;
a holding sleeve means (13, 14, 18) surrounding said jaws, and retaining said jaws in position, including a rotation-symmetrical coaxial sleeve (18) extending over said base body (1);
said holding sleeve means being rotatably positioned on the base body;
and
selectively engageable coupling means (22) located between said holding sleeve means (13, 14, 18) and said base body (1) which, upon relative rotation in the first direction of the holding sleeve means and the base body, release engagement between the holding sleeve means and the base body and, further, upon selective relative rotation in an opposite or second direction, engages and couples the holding sleeve means to the base body to thereby provide for tightening of the jaws about a tool held in the chuck,
wherein, in accordance with the invention,
said coupling means (22) comprises
a surrounding spring clutch or coupling including a spiral spring (22) coaxially located about the base body;
a first rotation-symmetrical zone (24) being located on the base body (1);
a second rotation-symmetrical zone (25) being located on the holding sleeve means (13, 14, 18) and positioned axially adjacent said first zone (24);
said spiral spring (22) spanning both said first and second zones (24, 25) for selectively connecting or disconnecting said base body and said holding sleeve means;
and
selectively operable coupling control means (23, 28) operatively associated with the spiral spring (22) for controlling release of coupling engagement of said spiral spring with both said zones.

12 more elements

Dependencies are inferred from the claim text.