2. The wire twister of claim 1 wherein the cavity is closed at one end and the conduit is connected therewith adjacent to the closed end thereof, a cylindrical insert having an axial opening therein positioned within the cavity and secured thereto in gastight relation with the insert extending from an extremity exterior of said head and terminating within the cavity adjacent the bottom thereof with the inner end of the insert being of a smaller diameter than the cavity, said flexible tubing being positioned within the axial opening of said insert and having the ends thereof fastened to the insert to define an expandable chamber between the exterior of the flexible tube and the wall of the insert, plug means positioned in the inner end of the flexible tube in sealing relation to seal off the cavity with respect to the inside of the flexible tube, and at least one radial passage through the wall of the cylindrical insert communicating the expandable chamber and the cavity.

3. The wire twister of claim 1 wherein a cap is received by an open end of the cavity in sealed relation with said cap having at least two parts therein communicating said cavity with the exterior of the head, said flexible tube having the ends thereof connected to said ports in gastight relation such that the ports communicate with the inside of the tube and the outside of the tube communicates with said cavity.

4. The wire twister of claim 1 including an outer hollow cylindrical member concentric with the twister head, a radial web interconnecting the outer cylindrical member and the twister head, bearing means carried on said outer cylindrical member, a support means, said bearing being mounted on the support means to provide for rotary movement of said outer cylinder and the twister head, and wherein said conduit means includes a radially extending passageway in said web extending from the inside surface of said cavity to the outside surface of the outer cylindrical member.

5. The wire twister according to claim 2 wherein the conduit means includes a radially extending bore connecting the cavity within the head and the exterior thereof, a circumferential groove in the outer surface of the head intersecting the bore, an annular slip ring overlying said groove in gastight relation for relative movement therewith and a radial opening through said slip ring in registry with said groove adapted for connection to a source of gas under pressure.

6. The wire twister according to claim 3 wherein the conduit means includes a radially extending bore connecting the cavity within the head and the exterior thereof, a circumferential groove in the outer surface of the head intersecting the bore, an annular slip ring overlying said groove in gastight relation for relative movement therewith and a radial opening through said slip ring in registry with said groove adapted for connection to a source of gas under pressure.

7. The wire twister according to claim 4 wherein the conduit means includes a radially extending bore connecting the cavity within the head and the exterior thereof, a circumferential groove in the outer surface of the head intersecting the bore, an annular slip ring overlying said groove in gastight relation for relative movement therewith and a radial opening through said slip ring in registry with said groove adapted for connection to a source of gas under pressure.

8. The wire twister according to claim 5 wherein the means operatively connected to rotate the head comprises an electric motor having a rotating shaft and the twister head is mounted directly upon the motor shaft for rotation.

9. The wire twister according to claim 5 wherein the means operatively connected to rotate the head comprises an electric motor having a rotating shaft mounting a pulley, a pulley connected to the head and a belt interconnecting the pulleys.

10. The wire twister according to claim 8 including a source of gas under pressure connected to said conduit, a valve in said conduit and timer means adapted to connect said motor to a source of electrical power for predetermined time periods.