| 摘要 |
<p>A drive roll assembly is disclosed for a push-pull MIG welding torch including a handle connected to a power cable assembly and a gooseneck. The drive roll assembly includes a body block disposed in the handle, a motorized driving gear mounted on the body block, and an idler wheel rotatably mounted on a mounting arm via a mount. The mounting arm is pivotally connected to the body block. The idler wheel is cooperable with the driving gear to pull welding wire from the cable assembly through the handle and towards the gooseneck. One of the idler wheel and the driving gear is made of a highly conductive material that allows for transfer of welding current to the welding wire. The electric resistance from the body block to the surfaces of the idler wheel and driving gear at which they contact welding wire is below 15 milli-ohms, preferably below 2.0 milli-ohms.</p> |
