Wire feed limiter

1. A wire conveying mechanism comprising a slip clutch mechanism connectable to a motor,

wherein the slip clutch mechanism is a push-type friction clutch having first and second moving parts and a shaft, the first moving part comprising a rotating disc received on the shaft and the second moving part comprising friction members mounted on a rotating member also received on the shaft, and

wherein the rotating disc is fixed relative to the shaft and the rotating member rotates freely relative to the shaft.

2. The wire conveying mechanism of claim 1 , wherein the slip clutch mechanism has a threshold resistance selection mechanism via which a threshold resistance can be selected in discrete increments.

3. The wire conveying mechanism of claim 1 , wherein the slip clutch mechanism has a threshold resistance selection mechanism via which a threshold resistance can be selected along a continuum.

4. The wire conveying mechanism of claim 1 , wherein the second moving part includes a gear.

5. The wire conveying mechanism of claim 4 , further comprising one or more wheels that frictionally engage with a wire to cause the wire to be conveyed, each such wheel including a second gear meshed with the gear of the second moving part.

6. The wire conveying mechanism of claim 1 , wherein the slip clutch mechanism further comprises a threshold resistance selection mechanism via which a threshold resistance can be selected, the threshold resistance selection mechanism including a spring that applies pressure against the rotating disc of the second moving part.

7. The wire conveying mechanism of claim 1 , wherein the slip clutch mechanism further comprises a threshold resistance selection mechanism via which a threshold resistance can be selected, the threshold resistance selection mechanism including a nut threadingly received on an end of the shaft and a helical spring between the nut and the second moving part.

8. The wire conveying mechanism of claim 1 , the second moving part includes a friction pad disc to which are secured friction pads and a gear to which the friction pad disc is secured.

9. The wire conveying mechanism of claim 4 , further comprising four wheels disposed in two wheel pairs, each of the four wheels frictionally engaging a wire to convey the wire relative to the four wheels, the wire being gripped between the wheels of each wheel pair, each wheel having a second gear meshed with the gear of the second moving part.

10. A metal-working apparatus comprising:

a wire feed gun; and

a wire feeder positioned to feed a wire to the wire feed gun,

wherein, the wire feeder includes a push-type friction slip clutch mechanism having first and second moving parts and a shaft, the first moving part comprising a rotating disc received on the shaft and the second moving part comprising friction members mounted on a rotating member also received on the shaft, and

wherein the rotating disc is fixed relative to the shaft and the rotating member rotates freely relative to the shaft.

11. The metal-working apparatus of claim 10 , wherein the push-type friction slip clutch mechanism has a threshold resistance selection mechanism via which a threshold resistance can be selected in discrete increments.

12. The metal-working apparatus of claim 10 , wherein the push-type friction slip clutch mechanism has a threshold resistance selection mechanism via which a threshold resistance can be selected along a continuum.

13. The metal-working apparatus of claim 10 , wherein the second moving part includes a gear.

14. The metal-working apparatus of claim 13 , further comprising one or more wheels that frictionally engage with the wire to cause the wire to be conveyed, each such wheel including a second gear meshed with the gear of the second moving part.

15. The metal-working apparatus of claim 12 , wherein the threshold resistance selection mechanism includes a spring that applies pressure against the rotating disc of the second moving part.

16. The metal-working apparatus of claim 12 , wherein the threshold resistance selection mechanism includes a nut threadingly received on an end of the shaft and a helical spring between the nut and the second moving part.

17. The metal-working apparatus of claim 10 , the second moving part includes a friction pad disc to which are secured friction pads and a gear to which the friction pad disc is secured.

18. The metal-working apparatus of claim 13 , comprising four wheels disposed in two wheel pairs, each wheel frictionally engaging the wire to convey the wire relative to the wheels, the wire being gripped between the wheels of each wheel pair, each wheel having a second gear meshed with the gear of the second moving part.

19. An apparatus comprising:

a wire feed gun;

a wire feeder positioned to feed a wire to the wire feed gun, the wire feeder including a slip clutch that prevents feeding of the wire when the wire encounters a resistance above a threshold,

wherein the slip clutch is a push-type friction clutch having first and second moving parts and a shaft, the first moving part comprising a rotating disc received on the shaft and the second moving part comprising friction members mounted on a rotating member also received on the shaft, and

wherein the rotating disc is fixed relative to the shaft and the rotating member rotates freely relative to the shaft.

20. The apparatus of claim 19 , wherein the slip clutch includes a threshold resistance selection mechanism via which the threshold resistance can be selected.

21. The apparatus of claim 19 , further comprising a high energy source that melts the wire exiting the wire feed gun.

22. The apparatus of claim 21 , further comprising an energy source that preheats the wire before it is melted by the high energy source.

23. The apparatus of claim 20 , wherein the slip clutch has a threshold resistance selection mechanism via which the threshold resistance can be selected in discrete increments.

24. The apparatus of claim 20 , wherein the slip clutch has a threshold resistance selection mechanism via which a threshold resistance can be selected along a continuum.

25. The apparatus of claim 19 , wherein the second moving part includes a gear.

26. The apparatus of claim 25 , further comprising one or more wheels that frictionally engage with the wire to cause the wire to be conveyed, each such wheel including a second gear meshed with the gear of the second moving part.

27. The apparatus of claim 20 , wherein the threshold resistance selection mechanism includes a spring that applies pressure against the rotating disc of the second moving part.

28. The apparatus of claim 20 , wherein the threshold resistance selection mechanism includes a nut threadingly received on an end of the shaft and a helical spring between the nut and the second moving part.

29. The apparatus of claim 19 , the second moving part includes a friction pad disc to which are secured friction pads and a gear to which the friction pad disc is secured.

30. The apparatus of claim 25 , wherein the slip clutch comprises four wheels disposed in two wheel pairs, each wheel frictionally engaging the wire to convey the wire relative to the wheels, the wire being gripped between the wheels of each wheel pair, each wheel having a second gear meshed with the gear of the second moving part.