| 摘要 |
An electrically powered hand tool, such as a staple gun, can employ an electrical driver, such as a solenoid, which is actuated by a trigger circuit in response to depression of a trigger on the handle of the device. The trigger circuit can include a circuit board dimensioned to fit into the handle of the staple gun, and having AC input leads. A circuit formed of conventional electronic components delivers a burst of power to output leads which are in turn connected to a driver solenoid. This circuit is actuated to deliver the power burst by opening of a switch formed of two switch members: one switch member has a first flexible resilient conductive leaf formed, e.g., of an alloy of copper, extending beyond an edge of the board; the other member has a flexible resilient leaf with a bent-in pointed end contacting a side of the first blade. These blades are biased against each other to form a normally-closed switch. When the first blade is moved in one direction, the switch opens. When the first blade returns in the other direction to close the switch, the pointed end of the other resilient leaf of blade scratches off corrosion at the contact area of the two members. This permits low current (1 ma) to be used as a control current through the switch.
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