| 摘要 |
A pressure release mechanism relieves pressure to a prescribed value in a caulking gun. The pressure release mechanism includes a slot positioned in the handle of the gun and a pin which slides in the slot. A pawl is pivotably attached to the pin and engages the teeth of a ratchet bar to rearward movement of the ratchet bar and piston. An outwardly biased operating lever with an upper cam shaped surface engages the pin and urges the pin and pawl towards the front end of the slot as caulking compound is extruded from the gun under pressure. When the operating lever is completely released, the cam surface permits a biasing spring to move the pawl and pin to the rear of the slot. The pawl is engaged with a ratchet bar tooth as it moves to the rear, and thereby allows the ratchet bar and piston to move rearwardly a limited distance, which relieves the pressure within the caulking gun sufficiently to stop the flow of caulking material.
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