Modular power hand tool

Abstract

A power handle module encloses rechargeable batteries which can be used to power a number of modular special-purpose tools which may be mounted to the power handle module. The power handle module includes a hand grip, a trigger switch operated by a trigger and a first connector for engagement with a second connector on the special-purpose tool. An interlock operator on the handle module may be moved between a guard position where it resists pressure to move the trigger and at least one armed position, in which position it allows the trigger to be pressed. A secondary switch is mounted within the power handle module. When the special-purpose tool is a fastener driver the secondary switch controls direction of rotation of the motor on the tool. The fastener-driving tool includes a link for mechanically joining the secondary switch and the interlock operator upon connection of the first and second connectors such that by moving the interlock operator between the first and second armed positions the secondary switch is moved between switch positions. When the special-purpose tool is a saw the secondary switch provides a safety interlock switch preventing inadvertent rotation of the motor on the tool. The saw tool includes an engagement face that engages the secondary switch upon connection of the first and second connectors to move the secondary switch to one of the switch positions and resilient means for biasing the interlock operator to the guard position.