Lathe comprising a guide bush

1. A lathe including:

a moving headstock designed to ensure the rotation and translation of a part to be machined in relation to an axis of translation and rotation; and

a guide bush designed to be attached to a frame of the lathe and including:

a bush spindle, and

a clamping mechanism,

the guide bush being designed to operate either in bush mode or in grip mode, wherein:

the guide bush is designed to be moveable axially in relation to the frame along said axis,

the lathe is designed to operate in a first mode in which the guide bush is driven axially by the moving headstock, and

the lathe is designed to operate in a second mode in which the axial position of the guide bush is static in relation to the frame.

2. The lathe as claimed in claim 1 , wherein the lathe has a first coupling device,

wherein said first coupling device is engageable/disengageable and operating between the guide bush and the moving headstock, and wherein said first coupling device is designed to axially couple the guide bush and the moving headstock along said axis.

3. The lathe as claimed in claim 1 , wherein the lathe further has a second coupling device, wherein said second coupling device is engageable/disengageable and operating between the guide bush and the frame, and wherein said second coupling device is designed to axially set the position of the guide bush in relation to the frame along said axis.

4. The lathe as claimed in claim 1 , wherein said guide bush includes a sheath of the bush at least partially surrounding at least one of the bush spindle and the clamping mechanism, wherein said sheath of the bush is designed to be linked to the frame by means of a link that enables an axial translational movement of said sheath of the bush in relation to the frame.

5. The lathe as claimed in claim 4 , wherein said link includes bearings designed to enable said axial translational movement of the sheath of the bush in relation to the frame.

6. The lathe as claimed in claim 4 , wherein the lathe has a first coupling device, wherein said first coupling device is engageable/disengageable and operating between the guide bush and the moving headstock, wherein said first coupling device is designed to axially couple the guide bush and the moving headstock along said axis, wherein an end portion of the sheath is designed to radially surround an end portion of the moving headstock, and wherein said first coupling device is designed to operate between said end portion of the sheath of the bush and said end portion of the moving headstock.

7. The lathe as claimed in claim 6 , wherein said first coupling device includes a braking device that is designed to operate radially on a surface of said end of the moving headstock such as to maintain an axial position of the moving headstock in relation to the sheath.

8. The lathe as claimed in claim 3 , wherein said second coupling device included a braking device that is designed to operate radially on a surface of the sheath of the bush such as to set an axial position of the sheath in relation to the frame.

9. The lathe as claimed in claim 1 , wherein the bush spindle and the clamping mechanism are linked to said sheath of the bush by a link having an axis of rotation that is coaxial with said axis.

10. The lathe as claimed in claim 9 , wherein the link includes roller bearings.

11. The lathe as claimed in claim 1 , wherein the lathe further includes a third coupling device designed to operate between the guide bush and the moving headstock, and wherein said third coupling device is designed to transmit a rotation of a rotary part of the moving headstock to the clamping mechanism of the bush and/or to the bush spindle.

12. The lathe as claimed in claim 11 , said third coupling device being engageable/disengageable.

13. The lathe as claimed in claim 11 , wherein an end portion of the bush spindle is designed to radially surround an end portion of said rotary part of the moving headstock, wherein said third coupling device includes a protuberance that cooperates with an axial slot, wherein the end portion of the bush spindle includes one of either said protuberance or said axial slot, and wherein said end portion of said rotary part of the moving headstock includes the other of said protuberance and said axial slot.

14. The lathe as claimed in claim 11 , wherein said moving headstock is motorized.

15. The lathe as claimed in claim 1 , wherein the guide bush is motorized.

16. The lathe as claimed in claim 1 , wherein the bush spindle and the clamping mechanism are designed to be axially detachable from the frame and/or the sheath of the bush.

17. The lathe as claimed in claim 16 , wherein the guide bush includes a bush body, said bush body radially enveloping the bush spindle and the clamping mechanism, and said bush body being designed to be axially detachable from the frame and/or the sheath of the bush.

18. The lathe as claimed in claim 16 , wherein the whole of the guide bush is designed to be axially detachable from the frame.

19. The lathe as claimed in claim 17 , wherein the whole of at least one of the bush and the bush body and the bush spindle and clamping mechanism are designed to be detachable from the side of the frame close to the machining zone.

20. The lathe as claimed in claim 1 , the bush spindle receiving and holding said clamping mechanism.

21. A guide bush for a lathe including:

a bush spindle;

a clamping mechanism; and

a sheath of the bush at least partially surrounding at least one of the bush spindle and the clamping mechanism,

wherein the guide bush is designed to operate either in bush mode or in grip mode,

wherein said sheath of the bush is designed to be linked to a frame of a lathe by a link enabling a translational movement of said sheath of the bush in relation to said frame that is substantially axial in relation to an axis of translation and rotation of a part to be machined when same is held by said guide bush, and

wherein the bush spindle and the clamping mechanism are designed to be detachable from said sheath, axially in relation to said axis, wherein said guide bush further includes a bush body, said bush body radially enveloping the bush spindle and the clamping mechanism, and wherein said bush body is designed to be detachable in relation to said sheath, axially in relation to said axis.

22. The guide bush as claimed in claim 21 , wherein said bush body is linked to said sheath via a plurality of detachable attachment elements which are accessible from the side of the machining zone.