Claims
- 1. A rotatable driving tool for imparting torque to a driven member, the tool comprising: a body having a longitudinal axis of rotation, and a plurality of driving portions projecting laterally from said body and equiangularly spaced about said axis, each of said driving portions having non-planar surfaces meeting to form an outer edge which defines a portion of a substantially circular helix having a helix angle less than six degrees, where a helix is a non-planar curve.
- 2. The driving tool of claim 1, wherein said body includes six of said driving portions.
- 3. The driving tool of claim 1, wherein each of said driving portions is in the form of a longitudinally elongated blade, said blades being separated by axially elongated concave grooves formed in said body.
- 4. The driving tool of claim 3, wherein said blades are respectively provided with outer peripheral surfaces which lie along a common circular cylinder.
- 5. The driving tool of claim 1, wherein the axial extent of said driving portions is less than one-quarter inch.
- 6. The driving tool of claim 1, wherein said helix angle is no greater than about six degrees.
- 7. The driving tool of claim 1, wherein said helix angle is in the range of from about one degree to about three degrees.
- 8. A rotatable driving tool for imparting torque to a rotatable driven member about an axis of rotation, the driven member having formed therein an axial recess having a plurality of equiangularly spaced-apart lobes each extending the full axial extent of the recess and having a longitudinal axis, said tool comprising: a body adapted to be received coaxially in the recess of the driven member, and a plurality of longitudinal driving portions on said body equal in number to and respectively receivable in the lobes when said body is received in the recess, each of said driving portions having a longitudinal axis inclined with respect to the longitudinal axis of the associated lobe and non-coplanar with the axis of rotation when said body is received in the recess, each of said driving portions having non-planar surfaces meeting to form an outer edge which defines a substantially circular helix, where a helix is a non-planar curve, whereby each of said driving portions engages in the associated lobe at longitudinally spaced-apart locations in a wedging interference fit to retain the driven member in engagement with said driving tool.
- 9. The driving tool of claim 8, wherein the longitudinal axis of each of said driving portions is inclined at an angle less than five degrees with respect to the longitudinal axis of the associated lobe.
- 10. The driving tool of claim 8, wherein each of said driving portions has a longitudinal outer edge having end points which are offset from each other in directions substantially normal to the axis of rotation.
- 11. The driving tool of claim 8, wherein each of said driving portions is substantially circularly helical having a helix angle less than five degrees.
- 12. The driving tool of claim 8, wherein each of said driving portions is in the form of an axially elongated blade having a pair of longitudinal outer side edges disposed substantially parallel to each other.
- 13. In combination: a driven member having a longitudinal axis of rotation, said driven member having formed in one end thereof an axial recess having a plurality of equiangularly spaced-apart lobes, each of said lobes extending the full axial extent of said recess and having a longitudinal axis; and a rotatable driving tool having a body adapted to be received coaxially in said recess for imparting torque to said driven member, said body including a plurality of driving portions equal in number to and respectively receivable in said lobes when said body is received in said recess, each of said driving portions having a longitudinal axis inclined with respect to the longitudinal axis of the associated lobe and non-coplanar with the axis of rotation when said body is received in said recess, each of said driving portions having non-planar surfaces meeting to form an outer edge which defines a substantially circular helix, where a helix is a non-planar curve; whereby each of said driving portions engages in the associated one of said lobes at longitudinally spaced-apart locations in a wedging interference fit to retain said driven member in engagement with said driving tool.
- 14. The combination of claim 13, wherein said driven member is a threaded fastener.
- 15. The combination of claim 14, wherein said fastener is a socket-head screw wherein the socket defines said recess.
- 16. The combination of claim 13, wherein the longitudinal axes of said lobes are substantially parallel to said axis of rotation.
- 17. The combination of claim 13, wherein each of said driving portions is substantially circularly helical having a helix angle of less than five degrees.
- 18. The combination of claim 13, wherein each of said driving portions is in the form of an axially elongated blade having an outer peripheral surface bounded by substantially parallel side edges spaced apart by a distance which is less than the width of the associated lobe by a predetermined clearance distance, the opposite ends of each of said edges being offset from each other in directions substantially normal to the axis of rotation a distance greater than said clearance distance.
- 19. The combination of claim 13, wherein each of said driving portions is shaped and arranged so as to engage in the associated one of said lobes at two locations, the innermost one of which is spaced a slight distance from the inner end of said recess to insure a wedge fit.
- 20. A combination of claim 13, wherein the number of said lobes and said driving portions is six.
Parent Case Info
This is a continuation of application Ser. No. 327,735, filed Mar. 23, 1989 abandoned.
US Referenced Citations (9)
Continuations (1)
|
Number |
Date |
Country |
Parent |
327735 |
Mar 1989 |
|