Extension apparatus between tool and tool bit

1. An extension apparatus for connecting a tool with a tool bit, the extension apparatus including a driving element with a first end for engagement with the tool and a second end for engagement with the tool bit; a telescopic element inserted in the driving element; a magnet attached to the telescopic element; a barrel movably mounted on the driving element for receiving a fastener to be driven by the tool bit, with the barrel having a first end and a second end, with an annular stop groove defined in an external side of the driving element adjacent the second end of the driving element; and a stop ring located in the annular stop groove of the driving element, with an annular stop groove defined in an internal side of the barrel between the first and second ends, with the annular stop groove of the barrel including an annular shoulder and an annular slope, with the annular shoulder located intermediate the annular slope and the first end of the barrel, with the annular shoulder abutting with the stop ring for keeping the barrel on the driving element, the annular slope having increasing spacing from the internal side in a direction toward the first end of the barrel facilitating removal of the stop ring from the annular stop groove formed in the barrel when moving the barrel toward the first end of the driving element.

2. The extension apparatus according to claim 1 wherein the driving element includes an insert formed at the first end and a socket formed at the second end.

3. The extension apparatus according to claim 2 including a detent, wherein the socket defines a space for receiving the tool bit and an aperture communicated with the space, and the detent is extensible into the space defined in the socket for contact with the tool bit.

4. The extension apparatus according to claim 3 including an elastic element for biasing the detent.

5. The extension apparatus according to claim 4 wherein the elastic element is a detent ring mounted on the socket.

6. The extension apparatus according to claim 5 wherein the detent ring is a C-ring.

7. The extension apparatus according to claim 5 wherein the socket defines an annular detent groove defined in an external side in order to receive the detent ring.

8. The extension apparatus according to claim 5 wherein the detent is a boss integrally extending from and formed as a single piece with the detent ring.

9. The extension apparatus according to claim 3 wherein the detent is a ball.

10. The extension apparatus according to claim 1 further comprising: an end ring, with an annular end groove formed in the driving element adjacent the first end of the driving element, with the end ring located in the annular end groove; and an annular slope defined in the internal side of the barrel at the first end of the barrel for abutting the end ring, with the annular slope at the first end of the barrel having decreasing spacing from the internal side in a direction toward the second end of the barrel.

11. The extension apparatus according to claim 10 wherein the driving element includes an insert formed at the first end and a socket formed at the second end.

12. The extension apparatus according to claim 11 including a detent, wherein the socket defines a space for receiving the tool bit and an aperture communicated with the space, and the detent is extensible into the space defined in the socket for contact with the tool bit.

13. The extension apparatus according to claim 12 including an elastic element for biasing the detent.

14. The extension apparatus according to claim 13 wherein the elastic element is a detent ring mounted on the socket.

15. The extension apparatus according to claim 14 wherein the detent ring is a C-ring.

16. The extension apparatus according to claim 14 wherein the socket defines an annular detent groove defined in an external side in order to receive the detent ring.

17. The extension apparatus according to claim 14 wherein the detent is a boss integrally extending from and formed as a single piece with the detent ring.

18. The extension apparatus according to claim 12 wherein the detent is a ball.

19. The extension ring according to claim 10 when the end ring is a C-ring.

20. The extension ring according to claim 1 wherein the stop ring is a C-ring.