Patent ID: 7273410

Claim:
A belt sander comprising: a frame including an upper transmission shaft, and a baffle at a front side of the frame; a sand belt engaged around the upper transmission shaft, two guiding blocks attached to the frame and disposed near to two lateral side edges of the sand belt and on two sides of a circulating path of the sand belt, and the guiding blocks each including an inclined surface in contact with the sand belt to automatically guide the sand belt that is laterally biased; two fitting seats fixed to the frame, two spring fitting rods inserted into the baffle of the frame; two springs received in the fitting seats; two connectors inserted into the fitting seats and restricted by the fitting seats and contacted with the springs, and a push rod attached to the connectors and contacted with the sand belt; the springs pushing the push rod outward to push the sand belt and to keep the sand belt in a tightened state.