Patent EA-001019-B1 (EA)
Title: Screwing element
Inventor: OSTERLE HELMUT
IPC: H04L12/54
Filed: 1998-02-16
Abstract: 1. A screwing element for holding and for forcibly turning a fastener (6), with a plurality of jaws (3, 4), which are disposed in succession in circumferential direction for seizing the fastener (6), wherein the jaws (3, 4) engage in a tubular holder (2) and, in combination with this holder (2), in a first end position can be forced radially apart for the purpose of holding the fastener, and in a second end position can be radially squeezed together by mechanical action of the holder (2) in response to application of axial and/or radial force, characterized in that incisions (15, 16) or recesses are formed on the free end region of the jaws (3, 4) for mechanical and/or frictional accommodation of a fastener head (5), and in that gripper-like parts (17, 18) jutting outwardly toward the central axis (24) or directed away therefrom are formed on the free end of the jaws (3,4), adjoining the incisions (15, 16) or recesses, for the purpose of additional mechanical and/or frictional seizing of portions of the fastener head (5). 2. A screwing element according to claim 1, characterized in that the incisions (15, 16) or recesses on the jaws (3, 4) correspond at least approximately to the cross section of the rim region of the fastener head (5) to be seized or of a shoulder (10) formed thereon. 3. A screwing element according to claim 1 and/or 2, characterized in that, in the region of the incisions (15, 16) or recesses or adjoining these in offset position in axial direction or even on the gripper-like parts (17, 18) there are provided openings or profiled structures for acting on the fastener head (5) or on portions thereof. 4. A screwing element according to claim 1, characterized in that the jaws (3, 4) are spring-loaded toward their open position. 5. A screwing element according to one of claims 1 to 4, characterized in that the thickness of the gripper-like parts (17, 18) viewed in axial direction of the screwing element (1 ) is smaller than the axial length (B) of a portion (12) on a fastener head (5), which on the shank side adjoins a circumferentially formed shoulder (10) at the fastener head (5). 6. A screwing element according to claim 1 and one of the preceding claims, characterized in that, on the inside of the holder (2) and/or on the outside surface of the jaws (3, 4), there are formed camming surfaces (25, 26) which taper sharply toward the central axis (24), wherein the jaws (3, 4) can be squeezed together by the camming surfaces (25, 26) in response to being forced axially into the holder (2). 7. A screwing element according to claim 6, characterized in that sharply tapering camming surfaces (25, 26) are provided on both the holder (2) and on the jaws (3, 4). 8. A screwing element according to claim 1 and one of the preceding claims, characterized in that the jaws (3, 4) are provided at their ends protruding into the tubular holder (2) with radially inwardly directed toes (27, 28), which engage in a radially circumferential groove (29) of a stud (30) that is axially slidable in the screwing element (1) and can be fixed in a plurality of latching positions, wherein this stud (30) can be positioned together with the jaws (3, 4) by the action of axial pushing or pulling thereon. 9. A screwing element according to claim 8, characterized in that the stud (30) can be fixed latchingly at least in the two end positions of the jaws (3, 4). 10. A screwing element according to claims 8 and 9, characterized in that the stud (30) is provided with at least two latching positions formed by circumferential grooves (33, 34), wherein a spring-loaded pin (36) or a ball which engages in the corresponding circumferential groove (33, 34) is held on the tubular holder (2). 11. A screwing element according to claim 8, characterized in that the stud (30) is adapted on its portion (31) adjoining the groove (29) for engagement with the toes (27, 28) formed on the jaws (3, 4) to the inside cross section of the jaws (3, 4) in closed condition, wherein the transition between the groove (29) and the end part (32) of the stud (30) and the corresponding regions of the jaws (3, 4) are spherically convex. 12. A screwing element according to claim 1 and one of the preceding claims, characterized in that a tool for an internal drive can be formed at the center between the jaws (3, 4). 13. A screwing element according to claims 1 and 12, characterized in that the tool for an internal drive is formed or disposed at the free end of the stud (30) which is slidable in the tubular holder (2). 14. A screwing element according to claim 1 and one of the preceding claims, characterized in that the jaws (3, 4) are forced resiliently toward each other by an O-ring (22) inlaid in a groove on the outside circumference of the jaws (3, 4) in the region of the inwardly projecting toes (27, 28), so that the jaws (3, 4) are pressed apart into open position when in their position withdrawn from the holder. 15. A screwing element according to claim 1 and one of the preceding claims, characterized in that compression springs (23) are inserted between the jaws (3, 4) in the region of their free ends, so that the jaws (3, 4), when in their position withdrawn from the holder (2), are forced apart into open position. 16. A screwing element according to claim 1 and one of the preceding claims, characterized in that the gripper-like parts (17, 18) are each extended over the entire sector region of the jaws (3, 4). 17. A screwing element according to claim 1 and one of the preceding claims, characterized in that there are provided two jaws (3, 4) extending approximately over an angular region of 18 degree C.