摘要 |
An impact drive tool is provided with a percussive piston arranged in a cylinder. A rod on the piston is mounted to drive a nail or other object into a workpiece. A valve arrangement is provided to apply compressed air to the upper surface of the piston, and a storage chamber communicating with the space below the piston is provided for returning the piston to a rest position. A plurality of sequentially arranged latching devices are provided for locking the piston in its rest position, the latching device effective at a given time being dependent on such factors as friction in the device and the amount of compressed air stored for the return stroke. A buffer surface is provided to effect the absorption of energy if the piston passes all of the latching devices, and to rebound the piston to the nearest latching device. |