| 摘要 |
A sonic generator produces a reciprocating force that is transmitted to a tool by a resonant or nonresonant force transmitting member having an output that reciprocates about a neutral position responsive to the force of the sonic generator. A continuous unidirectional force is applied to the sonic generator by a tool carrier. The tool advances intermittently along a work path through a medium responsive to the continuous unidirectional force and the reciprocating force. A gap is held between the neutral output position of the transmitting member and the tool when the tool is unable to advance through the medium responsive to the continuous unidirectional force and the reciprocating force. Specifically, the force of the sonic generator is sufficiently large relative to the unidirectional force to overcome the latter, and to drive the tool holder back away from the tool when the tool is unable to advance along the work path, thereby establishing a protective gap. When the force transmitting member is resonant, cessation of resonance is prevented when the tool encounters an immovable object by establishing the protective gap in the described manner.
|
