Contact tip contact arrangement for metal welding
A contact tip assembly having an electric contact unit containing a contact tip with an electric energy source, where the electric contact unit is positioned at a distance away from the outlet opening of a guide. The contact tip may be a replaceable tip that is biased or pressed into contact with a feed wire to apply a current from the electric energy source to the feed wire.
1 . A system for solid free form deposition comprising:
a plasma transfer arc torch configured to generate a plasma arc;
a base material positioned proximate the plasma transfer arc torch, the plasma transfer arc torch and the base material being movable relative to each other to facilitate free form deposition of a workpiece on the base material;
a contact tip assembly separate from the plasma transfer arc torch and conducting an electric current to a feed wire during deposition of the workpiece, the contact tip assembly comprising a replaceable contact tip laterally spaced from the welding torch, wherein the replaceable contact tip is configured to be biased into contact with the feed wire and wherein the replaceable contact tip is configured to conduct electrical current from an electrical energy source through the replaceable contact tip and to the feed wire; and
a wire guide comprising a first end through which the wire feed enters the wire guide and a second end through which the wire feed exits the wire guide, wherein the replaceable contact tip is disposed to contact the wire feed at a location between the first end and the second end of the wire guide.
2 . The system of claim 1 , wherein the wire guide is separate and apart from the contact tip assembly.
3 . The system of claim 2 , the wire guide further comprising an opening at a region above which the contact tip assembly conducts the electric current to the wire feed.
4 . The system of claim 1 , the contact tip assembly comprising a contact unit containing the replaceable contact tip.
5 . The system of claim 4 , the contact tip assembly further comprising a pressing assembly connected to the contact unit and configured to press the contact tip of the contact unit onto the feed wire.
6 . The system of claim 5 , the pressing assembly further comprising a spring, hydraulics, a pneumatic actuator, a mechanized screw, a motorized piston, or any combination thereof.
7 . The system of claim 1 , further comprising a wire feed pressing assembly configured to press the wire feed against the contact tip assembly.
8 . The system of claim 7 , wherein the wire feed pressing assembly is connected to a wire guide that is separate and apart from the contact tip assembly.
9 . A method of conducting an electrical current to a wire feed during solid free form manufacturing comprising:
feeding the wire feed through a wire guide that is separate and apart from a contact tip assembly and from a welding torch, the wire guide comprising a first end through which the wire feed enters the wire guide and a second end through which the wire feed exits the wire guide;
contacting the wire feed and a replaceable contact tip of the contact tip assembly at a location between the first end and the second end of the wire guide, wherein the contact tip assembly is spaced apart and separate from the welding torch; and
conducting an electrical current through the replaceable contact tip to the wire feed.
10 . The method of claim 9 , wherein the wire guide has an insulating lining defining a guide channel.
11 . The method of claim 9 , the wire guide comprising a wire feed pressing assembly pressing the wire feed against the contact tip.
12 . A contact tip assembly comprising:
a replaceable contact tip;
a contact unit containing the replaceable contact tip;
a pressing assembly connected to the contact unit at an opposite end of the contact unit from where the replaceable contact tip is located; and
a wire guide comprising a first end through which a wire feed enters the wire guide and a second end through which the wire feed exits the wire guide, wherein the replaceable contact tip is disposed to contact the wire feed at a location between the first end and the second end of the wire guide,
wherein the pressing assembly is configured to apply a force to the contact unit to press the replaceable contact tip into contact with the wire feed, and wherein the replaceable contact tip is configured to conduct an electrical current from an electrical energy source through the replaceable contact tip and to the wire feed.
13 . The contact tip assembly of claim 12 , further comprising an electrical connection configured to connect the contact tip with an electrical power source.
14 . The contact tip assembly of claim 13 , wherein the electrical power source comprises a DC power source.
15 . The contact tip assembly of claim 13 , wherein the electrical power source is coupled to a welding torch.
16 . The contact tip assembly of claim 15 , wherein the replaceable contact tip, the contact unit, and the pressing assembly are arranged to be spatially separated from the welding torch.
17 . The contact tip assembly of claim 16 , wherein at least one of the replaceable contact tip, the contact unit, and the pressing assembly is laterally spaced from the welding torch.
18 . The contact tip assembly of claim 12 , wherein the replaceable contact tip comprises copper or a copper alloy.
19 . The contact tip assembly of claim 12 , wherein the pressing assembly comprises a spring, hydraulics, a pneumatic actuator, a mechanized screw, a motorized piston, or any combination thereof.