Flex shaft-tool connection for power operated rotary knife

1. A driver assembly detachably coupled between a flexible shaft drive transmission having an outer casing and an elongated drive transmitting shaft rotatable within the outer casing and a handle assembly of a power operated tool to provide rotational power from a coupler fitting of the drive transmitting shaft and a drive train of the power operated tool, the driver assembly comprising:

a) a tube assembly comprising a main tube defining first and second ends and a throughbore, the first end of the main tube defining a distal end wall of the main tube and the second end of the main tube defining a proximal end wall of the main tube, and first and second bushings disposed within the throughbore at the respective first and second ends of the main tube and a casing coupler secured to and extending beyond the proximal end wall of the second end of the main tube, the casing coupler configured to releasably attach the driver assembly to the outer casing; and

b) an elongated shaft supported for rotation by the first and second bushings of the tube assembly, a first end portion of the shaft rotatably supported in the first bushing and a second end portion of the shaft rotatably supported in the second bushing, the first end portion of the elongated shaft including a driver fitting extending axially beyond the distal end wall of the first end of the main tube, the first bushing contacting the first end of the main tube and extending beyond the distal end wall of the first end of the main tube and defining a first bushing distal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in a first direction, the second end portion of the elongated shaft including a driven fitting extending axially beyond the proximal end wall of the second end of the main tube, the second bushing contacting the second end of the main tube and extending beyond the proximal end wall of the second end of the main tube and including a second bushing proximal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in a direction opposite of the first direction.

2. The driver assembly of claim 1 wherein an enlarged end of the first bushing extends axially beyond the distal end wall of the first end of the main tube and an enlarged end of the second bushing extends axially beyond the proximal end wall of the second end of the main tube.

3. The driver assembly of claim 2 wherein the enlarged end of the first bushing defines the first bushing distal end wall of the first bushing.

4. The driver assembly of claim 2 wherein the enlarged end of the second bushing defines the second bushing proximal end wall of the second bushing.

5. The driver assembly of claim 1 wherein the driver fitting of the elongated shaft includes an enlarged head which abuts the first bushing distal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in the first direction.

6. The driver assembly of claim 1 wherein the second end portion of the elongated shaft includes a stop which abuts the second bushing proximal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in the direction opposite the first direction.

7. The driver assembly of claim 1 wherein the first end portion of the elongated shaft supported in the first bushing has an enlarged diameter with respect to a central portion of the elongated shaft.

8. The driver assembly of claim 1 wherein the second end portion of the elongated shaft supported in the second bushing has an enlarged diameter with respect to a central portion of the elongated shaft.

9. The driver assembly of claim 1 wherein the driver fitting is attached to the elongated shaft by a threaded connection.

10. The driver assembly of claim 1 wherein the casing coupler of tube assembly is attached to the main tube by a threaded connection.

11. The driver assembly of claim 1 wherein the main tube is rigid.

12. The driver assembly of claim 1 wherein the first bushing distal end wall of the first bushing is axially spaced from the distal end wall of the first end of the main tube and the second bushing proximal end wall of the second bushing is axially spaced from the proximal end wall of the second end of the main tube.

13. A driver assembly detachably coupled between a flexible shaft drive transmission having an outer casing and an elongated drive transmitting shaft rotatable within the outer casing and a power operated tool, the driver assembly comprising:

a) a tube assembly comprising a main tube defining first and second ends and a throughbore, the first end of the main tube defining a distal end wall of the main tube and the second end of the main tube defining a proximal end wall of the main tube, and first and second bushings disposed within the throughbore at the respective first and second ends of the main tube; and

b) an elongated shaft supported for rotation by the first and second bushings of the tube assembly, a first end portion of the shaft rotatably supported in the first bushing and a second end portion of the shaft rotatably supported in the second bushing, the first end portion of the elongated shaft including a driver fitting extending axially beyond the distal end wall of the first end of the main tube, the first bushing contacting the first end of the main tube and extending beyond the distal end wall of the first end of the main tube and defining a first bushing distal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in a first direction, the second end portion of the elongated shaft including a driven fitting extending axially beyond the proximal end wall of the second end of the main tube, the second bushing contacting the second end of the main tube and extending beyond the proximal end wall of the second end of the main tube and including a second bushing proximal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in a direction opposite of the first direction.

14. The driver assembly of claim 13 further including a casing coupler configured to releasably attach the driver assembly to the outer casing of the flexible shaft drive transmission, the casing coupler is secured to and extends beyond the proximal end wall of the second end of the main tube.

15. The driver assembly of claim 13 wherein an enlarged end of the first bushing extends axially beyond the distal end wall of the first end of the main tube, the enlarged end of the first bushing defining the first bushing distal end wall of the first bushing.

16. The driver assembly of claim 13 wherein an enlarged end of the second bushing extends axially beyond the proximal end wall of the second end of the main tube, the enlarged end of the second bushing defining the second bushing proximal end wall of the second bushing.

17. The driver assembly of claim 13 wherein the driver fitting of the elongated shaft includes an enlarged head which abuts the first bushing distal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in the first direction.

18. The driver assembly of claim 13 wherein the second end portion of the elongated shaft includes a stop which abuts the second bushing proximal end wall to constrain axial movement of the elongated shaft with respect to the tube assembly in the direction opposite the first direction.

19. The driver assembly of claim 13 wherein the first end portion of the elongated shaft supported in the first bushing has an enlarged diameter with respect to a central portion of the elongated shaft and the second end portion of the elongated shaft supported in the second bushing has an enlarged diameter with respect to a central portion of the elongated shaft.

20. The driver assembly of claim 13 wherein the first bushing distal end wall of the first bushing is axially spaced from the distal end wall of the first end of the main tube and the second bushing proximal end wall of the second bushing is axially spaced from the proximal end wall of the second end of the main tube.