Patent ID: 7090571

Claim:
A belt sander, comprising: a base; a sanding device mounted on an upper portion of the base; a worktable mounted on a front portion of the sanding device; a tipping drive device mounted on a first side of the sanding device; a swinging device mounted on a second side of the sanding device; wherein the swinging device includes: a cylindrical roller rotatably mounted on the second side of the sanding device and rotated by the sanding device; a central shaft mounted in the roller to rotate therewith; a toothed ring mounted on a lower end of the central shaft to rotate therewith; a drive gear meshing with and rotated by the toothed ring; a cam mounted on and rotated by the drive gear; a fixing rod mounted on the cam to rotate therewith and connected to the roller to swing the roller by rotation of the cam to produce a reciprocally swinging action by a restoring spring; wherein the swinging device further includes a substantially U-shaped first support bracket for mounting the roller, and a substantially U-shaped second support bracket mounted on the first support bracket; the swinging device further includes a drawing rod having a first end locked on the first support bracket for drawing the first support bracket to swing the roller; and the restoring spring has a first end mounted on a second end of the drawing rod and a second end transversely mounted on the fixing rod.