Patent ID: 8197308

Claim:
A swing device for a grinding machine comprising: a feeding table; a frame located above the feeding table; two rotating stems rotatably connected to the frame and a sanding belt rotatably mounted to the two rotating stems; a fixed table adapted to be connected to an end of the frame of the grinding machine; a motor connected to a fixing member on the fixed table and including a shaft which is rotatably supported on a support member; a movable member movably mounted to the shaft and two support rolling members connected to two sides of the movable member, the movable member having an elongated slot; a fixed plate fixed to an end plate which is adapted to be connected to an end of one of the two rotating stems, the fixed plate having a hole and a link having a first end engaged with the hole and a second end of the link movably inserted into the elongated slot; two limit switches connected on the fixed table and the movable member being movable between the two limit switches, two action ends connected to the two limit switches respectively; two micro switches connected to a support frame and adapted to be located on two sides of the sanding belt, the support frame adapted to support one of the two rotating stems, and the movable member being movable along the shaft and activating the two action ends of the two limit switches alternatively to stop operation of the motor, the micro switches adapted to be activated by the sanding belt to change a rotation direction of the shaft.