Quick-action bar clamp

DETAILED DESCRIPTION Generally speaking, in accordance with the invention, a bar clamp especially suitable for rapid and precise closure against a workpiece is provided.
The clamp includes a fixed jaw and a movable jaw opposing the fixed jaw.
The movable jaw connects at one end to a slide bar which is movable to bring the movable jaw toward and away from the fixed jaw.
One-way drive means, by operation of a trigger handle grip, releasably engages the slide bar and advances the movable jaw toward the fixed jaw.
The one-way drive means is incapable of moving the slide bar and movable jaw away from the fixed jaw.
Return motion of the movable jaw is accomplished manually when the one-way drive means is disengaged.
A first braking lever which is biased to bind against the slide bar prevents reverse motion of the movable jaw away from the fixed jaw, except when the first lever is disengaged from the slide bar.
Thus, for return motion of the jaw, it is necessary that both the one-way drive means and the first braking lever be disengaged.
The trigger handle advances the slide bar by driving a second lever which binds against a surface of the slide bar and moves the rod as the second lever moves toward the fixed jaw.
The second lever is returned by spring force to its original position after each stroke of the trigger handle, the second lever sliding over the bar surface during its return motion.
Accordingly, it is an object of this invention to provide an improved quick-action bar clamp wherein the moving jaw may be moved over short and long distances rapidly.
Another object of this invention is to provide an improved quick-action bar clamp, wherein the moving jaw may be incrementally and precisely advanced from any position.
A further object of this invention is to provide an improved quick-action bar clamp wherein the moving jaw may be advanced in increments of selectable length for each action of a driving handle.
Yet another object of this invention is to provide an improved quick-action bar clamp wherein the movable jaw does not move of its weight when the clamp is in a vertical position