Patent ID: 6913091

Claim:
An impactor, comprising: a head having a rearwardly opening recess and a front end opening that communicates with the recess; an inlet pipe connectable at its front end to a pulling device and extending into the recess of the head through the front end opening, and having a pulling connection by which the impactor can be pulled while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the pulling device; a striker mounted for sliding movement along the inlet pipe; a distributing mechanism which receives pressure fluid supplied through the inlet pipe to cause the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the head; and a valve which regulates supply of pressure fluid to the distributing mechanism, including a front portion of the inlet pipe which assumes a first position in response to pulling force exerted on the inlet pipe by the pulling device that causes the distributing mechanism to reciprocate the striker, and a second position in which relaxing of the pulling force on the inlet pipe causes the distributing mechanism to cease reciprocating the striker, and a passage that permits pressure fluid in the inlet pipe to exhaust to the atmosphere when the valve is in the second position.