A sander is a commonly used power tool, which is used to polish a work surface typically of wood. Generally, the sander includes a motor, a transmission system providing movement in an eccentric direction, and a sanding plate. During operation, the eccentric rotational movement of the motor is transferred to the sanding plate through the transmission system. Sanding paper or another suitable sanding material is attached to the lower surface of the sanding plate, which is moved together with the sanding plate to polish the work surface.
Prior art sanders have certain disadvantages. For example, the eccentric movement of the sanding plate may unbalance the sander, causing excessive vibrations of the sander. When operating the sander for extended periods of time, the excess vibration may cause the user to become fatigued and the sander hard to control. Two methods are typically used to solve this problem. First, a balance system may be provided to reduce the imbalance and vibration of the sander. Second, a soft rubber or polyurethane material may be used to overlay the grip portion, such that the grip comfort is improved. However, neither of these methods substantially and effectively reduces the vibration of the sander. The present invention provides a sander having reduced vibration for easier handling.