Torch for thermal spraying of surface coatings, and coatings obtained thereby

1. A torch ( 1 ) configured for thermal spraying of surface coatings, comprising:

a head ( 3 ) in which an electric arc is struck between a cathode tip and an inside of an anode for plasma generation, the cathode tip and the anode both being internally water cooled, the head ( 3 ) comprising a delivery unit ( 20 ), and conduits are provided on said delivery unit ( 20 ) for connection with corresponding delivery and outlet pipes ( 7 , 8 ), which are configured to be connected with cavities for water circulation of the head ( 3 );

a bracket ( 2 ) for supporting the head ( 3 ), said head ( 3 ) pivots relative to the bracket ( 2 ), the bracket being connected to a guide arm; and

two side plates ( 4 ) joining the head ( 4 ) and the bracket ( 2 ) together, the plates ( 4 ) being welded to the bracket ( 2 ) and each plate ( 4 ) having a hole for connection with a corresponding part of the head ( 3 ) so that the head ( 4 ) can pivot relative to the bracket ( 2 ), wherein

said delivery unit ( 20 ) has housings formed therein for connection with joints ( 11 ) of the delivery ( 7 ) and outlet ( 8 ) pipes of the cooling water circuit and each of said housings comprises a gasket for watertight connection with the corresponding joint, and

a center of rotation of the head ( 3 ) relative to the bracket ( 2 ) passes through an axis of the holes ( 5 ) not being coaxial with the an axis of the joints ( 11 ).

2. The torch ( 1 ) as claimed in claim 1 , wherein said gaskets are made of an insulating material to seal the head ( 3 ) from the torch ( 1 ).

3. The torch ( 1 ) as claimed in claims 1 , wherein as the head ( 3 ) pivots, the housings rotate over the corresponding joints ( 11 ), a center of rotation of the head ( 3 ) not being coaxial with the axis of the joints.

4. The torch ( 1 ) as claimed in claim 1 , wherein the delivery and outlet pipes ( 7 , 8 ) translate during rotation of the head ( 3 ) and are supported by respective brackets ( 33 ).

5. The torch ( 1 ) as claimed in claim 4 , wherein said brackets ( 33 ) are also used to carry current to the anode and cathode of the head ( 3 ).

6. The torch ( 1 ) as claimed in claim 1 , wherein the delivery unit ( 20 ) holds the conduits for connection with the respective delivery and outlet pipes ( 7 , 8 ) and a plasmagenic gas inlet conduit ( 50 ).

7. The torch ( 1 ) as claimed in claim 1 , wherein the pivotal motion of the head ( 3 ) is either a continuous or a discrete motion.

8. The torch ( 1 ) as claimed in claim 1 , wherein it can spray any coating, whether of polymer, metal or ceramic materials, on any substrate, whether of polymer, metal, ceramic or composite material.

9. The torch ( 1 ) as claimed in claim 1 , wherein the torch is applicable to different thermal spray torches, using plasma spray, combustion spray, High Velocity Oxygen Fuel (HVOF), or Low Velocity processes.

10. The torch ( 1 ) as claimed in claim 1 , wherein the pivotal motion of the head ( 3 ) is controlled by means of a hydraulic or pneumatic cylinder.

11. The torch ( 1 ) as claimed in claim 10 , wherein the pivotal motion of the head ( 3 ) is controlled by an electric motor.

12. A coating obtained using the torch as claimed in claim 1 , said coating being of polymer, metal or ceramic materials, on any substrate, whether of polymer, metal, ceramic or composite material.

13. The torch ( 1 ) as claimed in claim 1 , wherein said pivotal motion is in a range of angles from −135° to +135° with respect to an axis ( 100 ) of the bracket ( 2 ).

14. The torch ( 1 ) as claimed in claim 1 , wherein said pivotal motion is in a range of angles from −45° to +45° with respect to an axis ( 100 ) of the bracket ( 2 ).

15. The torch ( 1 ) as claimed in claim 1 , wherein the bracket ( 2 ) has two side plates ( 4 ) attached thereto, each having a hole for connection with corresponding holes ( 5 ) formed on two side flanks ( 6 a ) of a hinge support ( 6 ) on which the head ( 3 ) is attached.

16. The torch as claimed in claim 1 , wherein a hydraulic or pneumatic or electric cylinder is configured for controlling the pivotal motion of the head ( 3 ), said pivotal motion of the head ( 3 ) occurs by application of a force (F) at a hole ( 19 ) of a support ( 6 ), the force (F) for causing pivotal motion of the head ( 3 ) may be exerted by the hydraulic or pneumatic or electric cylinder having a piston connected to the hole ( 5 ) of the support ( 6 ), and the cylinder is located on the bracket ( 2 ) alongside water pipes ( 7 ) and ( 8 ).