| 摘要 |
A pneumatic nailing machine includes a piston and driver assembly movably disposed in a striking cylinder for driving a fastener out of a front end of a main housing when primary pressured air is supplied to the cylinder, a head valve forced open when an active pressure generated as a result of flow of the primary pressured air is higher than a counter pressure in a counter-pressure zone, and an air valve unit convertible, in response to a throttling action applied to supply of secondary pressured air into the counter pressure zone, between a led-through state, where the head valve is kept unmoved in a closed position, and a shut-off state, where the flow of the secondary pressured air is disrupted thereby forcing the head valve forced open. |
