Abstract: A belt sander is described which comprises a support structure, a motor driven pulley secured to the support structure, a primary pulley secured to the support structure spaced from the motor driven pulley, an optional secondary pulley which can be installed over the primary pulley, and an endless belt, having an abrasive material along one face contacting the wood to be shaped, traveling about the pulleys. The sander further includes a belt tracking adjustment system, a work table adjustable relative to the endless belt and a dust guard having an aperture for allowing a vacuum system to be connected thereto.

Abstract: A fiber optic switch is provided for regulating light transmission comprising an encasing movement body surrounding a paramagnetic shaft, a section of which protrudes therefrom. A spring member surrounds the shaft protruding from the encasing movement body. At the end of the shaft opposite that of the protruding section is a light intercepting surface alignable with an end surface of at least one optical fiber. When a magnet outside the encasing body approaches sufficiently close to the shaft, magnetic forces attract the shaft overcoming the restraining spring and cause the light intercepting surface to move out of alignment with ends of the optical fiber, thereby making or breaking a light circuit.