Stud Extracting Device (Patent No: 957489)

Inventor: Dorosh, Michael

Location: Boyle

Comments: N/A

Description: The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A torque transmitting device for insertion into an orifice in a workpiece, said device comprising a shaft with at least a portion thereof provided with a plurality of longitudinal slots therein, a workpiece engaging blade extending along each said slot, and means for displacing each blade outwardly of said shaft, each said blade formed with an outer cutting edge for biting engagement with said workpiece to apply a torque thereto upon turning of said shaft.

2. A torque transmitting device as claimed in claim 1, wherein said shaft is provided with means for engagement with torque applying means.

3. A torque transmitting device as claimed in claim 2, wherein said shaft comprises a first portion carrying said means for engagement with torque applying means and a second portion coextensive with said first portion, said second portion having said slots therein the bottom surfaces of said slots flared outwardly away from said first shaft portion and each said blade adapted for sliding contact with the bottom surface of its respective slot.

4. A torque transmitting device as claimed in claim 3, wherein said first shaft portion is threaded and said means for engagement with torque applying means comprises an internally threaded member threadedly engaged with said first shaft portion and adapted to move upon rotation thereof along said first shaft portion into abutment with said blades and, upon further rotation thereof, to cause each said blade to slide along the respective slot bottom surface associated therewith and outwardly from said first shaft portion into biting engagement with said workpiece.

5. A torque transmitting device as claimed in claim 4 wherein said internally threaded member is a nut.

6. A torque transmitting device as claimed in claim 1 or claim 2, wherein each said blade is biased outwardly of its associated slot under the influence of resilient means located between said blade and the bottom surface of said slot.

7. A torque transmitting device as claimed in claim 2 wherein each said blade is biased outwardly of its associated slot under the influence of resilient means located between said blade and the bottom surface of said slot, and said means for engagement with torque applying means is integral with said shaft.

8. A torque transmitting device as claimed in claim 7 wherein said resilient means are compression springs.

9. A torque transmitting device as claimed in claim 7 or claim 8, wherein said means for engagement with torque applying means is a polygonally shaped extension of said shaft.

10. A torque transmitting device as claimed in claim 3 wherein each said blade is formed with said cutting edge and a rear edge, said rear edge adapted for sliding contact with the bottom surface of its respective slot, and said cutting edge subtending an angle with said rear edge approximately equal to the angle of flare of said slot bottom surface from said shaft axis, whereby said cutting edge of each said blade is generally parallel to said shaft axis.

11. A torque transmitting device as claimed in claim 1, wherein each said blade is biased outwardly of its associated slot under the influence of resilient means located between said blade and the bottom surface of said slot, each said blade formed with said cutting edge and a rear edge, said resilient means located between said rear edge and said slot bottom surface and said cutting edge flared towards one end thereof with respect to the axis of said shaft.

12. A torque transmitting device as claimed in claim 2, wherein each said blade is biased outwardly of its associated slot under the influence of resilient means located between said blade and the bottom surface of said slot, each said blade formed with said cutting edge and a rear edge, said resilient means located between said rear edge and said slot bottom surface and said cutting edge tapered towards one end thereof remote from said means for engagement with torque applying means with respect to the axis of said shaft.

13. A torque transmitting device as claimed in claim 10, wherein said blade is chamfered at one end thereof adjacent the shallow end of said slot.

14. A torque transmitting device as claimed in claim 11 or claim 12, wherein said blade is chamfered at said one end thereof.

15. A torque transmitting device as claimed in claim 1, wherein each said blade is provided with an outwardly extending tab adapted for engagement with means for removal of said device from said workpiece.

16. A torque transmitting device as claimed in claim 3, wherein each said blade is provided at or adjacent an extremity thereof adjacent said first shaft portion with an outwardly extending tab adapted for engagement with means for removal of said device from said workpiece.

17. A torque transmitting device as claimed in claim 4 or claim 5, wherein said first shaft portion is provided with longitudinally extending flats.