| 摘要 |
A drill press includes a motor having a rotatable shaft and a stepped motor pulley mounted on the rotatable shaft, a rotatable spindle and a stepped spindle pulley mounted on the rotatable spindle, and a stepped center pulley located between the motor pulley and the spindle pulley. A first drive belt connects the center pulley with the motor pulley, and a second drive belt connects the spindle pulley with the center pulley. A spring-loaded drive belt tensioner applies tension to the first drive belt. The belt tensioner has a first position for applying a first level of tension to the first drive belt and a second position for applying a second level of tension to said first drive belt that is less than the first tension level. When the belt tensioner is in the second position, the positions of the belts on the stepped pulleys are changeable. |
