Patent ID: 7445139
Filing Date: 2008-11-04
Classification: B25C

Abstract:
1. A driving power tool for driving a driving material into a workpiece, comprising: a coil spring that builds up a spring force, an operating member that is mounted on the end of the coil spring and linearly operates by free extension of the coil spring having the built-up spring force and thereby applies a driving force to the driving material, a drive member that drives the coil spring and thereby builds up the spring force on the coil spring, a rotating element that rotates in a normal direction against the spring force of the coil spring as the drive member drives the coil spring, an outer edge of the rotating element, including a first vertical wall formed at the circumferential direction of the rotating element, the first vertical wall formed between a front end region of the first outer edge portion and a rear end region of the second outer edge portion so as to at least partially transition the circumferential direction of the rotating element from the first outer edge portion to the second outer edge portion, a second vertical wall formed at the circumferential direction of the rotating element, the second vertical wall formed between a rear end region of the first outer edge portion and a front end region of the second outer edge portion, in the normal direction of rotation of the rotating element, so as to at least partially transition the circumferential direction of the rotating element from the first outer edge portion to the second outer edge portion, an engaging member that moves outward in the radial direction of the rotating element toward the first outer edge portion, the engaging member at least partially transitioning from the second outer edge to the first outer edge at the first vertical wall, the engaging member able to slide alone the first outer edge portion and thereafter moves inward in the radial direction of the rotating element and at least partially transition toward the second outer edge portion at the second vertical wall, the engaging member then returning back to the state of engagement with the second outer edge portion, as the rotating element rotates in the normal direction when the coil spring is driven by the drive member, whereby the engaging member defines a working stroke of the driving operation, a lock avoiding mechanism that avoids the engaging member from being locked to the second vertical wall by the spring force of the coil spring being transmitted to the engaging member via the second vertical wall in the process in which the engaging member moves inward in the radial direction of the rotating element toward the second outer edge portion the second vertical wall, a gear that is connected to the rotating element via the lock avoiding mechanism and inputs driving torque to the lock avoiding mechanism as the coil spring is driven by the drive member, wherein the lock avoiding mechanism allows relative rotation between the gear and the rotating element and includes an engagement pin provided on one of the gear and the rotating element, an engagement groove provided on the other of the gear and the rotating element and extending in an elongated manner along the direction of relative rotation between the gear and the rotating element to vary the position of the relative rotation between the gear and the rotating element, and a locking part to lock the engagement pin within the engagement groove.