Abstract: A grinding device for grinding a cylinder that has a rotating shaft includes an immovable component, a movable component, and a grinding component. The immovable component has a positioning unit. The cylinder has the rotating shaft positioned by the positioning unit. The movable component has a carrying portion and is such installed on the immovable component that the movable component can move axially along the rotating shaft. The carrying portion positionally corresponds to the cylinder. The grinding component is located on the carrying portion and positionally corresponds to a surface of the rotating shaft. The grinding device thereby is able to grind the rotating shaft of the cylinder evenly with reduced labor costs.

Abstract: A belt sander includes a frame, a support seat, a first wheel rod, a second wheel rod, a sand belt, an adjusting unit, and an operation unit. Thus, the operation handle of the operation unit is rotated to rotate the drive shaft which rotates the drive bevel gear which rotates the driven bevel gear which rotates the driven shaft which rotates the threaded rod to move the slide rod by rotation of the threaded rod so that the slide rod moves the support seat relative to the frame to move the first wheel rod relative to the second wheel rod to change the distance between the first wheel rod and the second wheel rod so as to adjust the tension of the sand belt.

Abstract: A belt sander includes a main frame, a drive roller, a driven roller, a sand belt, and a sand belt replacement apparatus. Thus, the user only needs to rotate the control handle to move the driven roller relative to the drive roller so as to change the distance between the drive roller and the driven roller so that the user can adjust the tension of the sand belt easily and rapidly, thereby facilitating the user adjusting the tension of the sand belt, and thereby facilitating the user mounting and replacing the sand belt.

Abstract: A sander includes two sander wheels of different sanding devices are rotatable secured on top of a frame. A work table is slidably disposed in the frame for supporting work pieces and for moving the work pieces toward the sander wheels. A pair of rollers are rotatable supported beside the sander wheels for feeding the work pieces passing through the sander wheels. A motor is coupled to the sander wheels and the rollers for driving the sander wheels and the rollers simultaneously. A reduction gearing is coupled to the rollers to drive the rollers in a reduced speed.

Abstract: The present invention is directed to a vertical/horizontal double-way grinding abrasive belt grinder which includes a base and a horizontal grinding wheel head. The base has a vertical grinding wheel and an assembly chamber arranged at its top. The vertical grinding wheel can be adjusted within an angle of 45.degree. with respect to the top of the base. The assembly chamber includes four positioning blocks respectively spaced about an opening at the top of the base for mounting thereon a cover plate or the horizontal grinding wheel head. The horizontal grinding wheel includes a housing and an abrasive belt wheel which are arranged to cooperate with the vertical grinding wheel for an abrasive belt to rotate thereabout.