Clutch for drilling machine

摘要

A drilling machine operable by a single operator to tap into a pipeline includes an elongated boring bar to which a number of different tools such as drills and hole saws may be removably attached. The boring bar is positioned within a body tube allowing rotation of the boring bar relative to the body tube. The body tube is positioned within an internally threaded feed tube such that as the feed tube is rotated, the boring bar is advanced. Manual or automatic driving equipment is secured to the boring bar to rotate the tool. A clutch mechanically couples the rotation of the driving equipment to the feed tube to move the tool into the pipeline at a controlled rate. The clutch includes a feed nut threadably secured to the feed tube. Adjacent the feed nut is a clutch member slideably secured to the feed tube. A biasing member such as a wave spring is position between the feed nut and the clutch member. A clutch disc is rigidly secured to the boring bar adjacent the clutch member and a friction disc of organic metal impregnated material is positioned between the clutch disc and clutch member. The clutch disc and clutch member each includes a surface engaging the friction disc. Each of these surfaces is treated to provide high frictional interaction with the friction disc and in the preferred embodiment the surfaces are serrated.