| 摘要 |
<p>HAMMER A fluid operable hammer has a hammer piston reciprocably slidable in an elongated bore of a body member so as to provide work and return strokes. The piston defines a variable volume chamber in the bore which chamber is supplied with hydraulic fluid to effect the return strokes. A valve is selectively movable to a first position to permit the supply of hydraulic fluid to the variable volume chamber, and to a second position whereby an exhaust chamber can receive hydraulic fluid from the variable volume chamber. With the valve in the second position a work stroke may be accomplished, while a return stroke is effected with the valve in the first position. The valve is constructed so that hydraulic fluid is discharged from the exhaust chamber as the valve moves from the second position to the first position. The hammer is simplified in construction and may, contrary to prior art devices be operated in any and all orientations. Furthermore hydraulic fluid back pressure, which limits piston movement, is minimized.</p> |
