| 摘要 |
A nailer for driving a fastener into a workpiece and comprising a main body defining a fastener ejection channel. A plunger is movably carried by the main body and defines a first end for receiving forceful mallet blows and a second end for engaging the fastener, the plunger also comprising a series of teeth and grooves and defining a longitudinal cavity extending between the first and second ends, the plunger being movable relative to the main body between a first limit position in which the plunger second end clears the fastener ejection channel, and a second limit position in which the plunger second end engages the fastener ejection channel. A stem member is carried by the nailer main body and penetrates the plunger longitudinal cavity, the stem member carrying a spring-loaded pawl capable of unidirectional releasable interlocking engagement with the teeth and grooves of the plunger. A plunger biasing member continuously biases the plunger towards the first limit position. Upon a forceful blow being applied to the plunger first end, the plunger will be forced from its first towards its second limit positions and if the plunger is forced to an intermediate position between its first and second limit positions, the pawl will engage in unidirectional releasable interlocking fashion in the teeth sand grooves of the plunger to retain the plunger in this intermediate position against the bias of the plunger biasing member whereby the plunger may be gradually moved with several forceful blows from the first to the second limit position without moving back towards its first limit position until it reaches the second limit position.
|
