Ratcheting open end wrench

A ratcheting open end wrench comprising:

• a wrench body;
• a fixed jaw projecting from said wrench body, said fixed jaw having a wrenching face;
• a movable jaw extending from said wrench body, said movable jaw having a wrenching face disposed opposite said fixed jaw wrenching face with a wrenching space therebetween configured to receive an element having a contour to be wrenched and engage the contour thereof;
• means mounting said movable jaw on said wrench body so as to be freely movable from an extended position to a retracted position upon rotation of said wrench body in a direction tending to push said element to be wrenched with said movable jaw, said retraction of said movable jaw causing an increase in the width of said wrenching space enabling said wrenching face of said movable jaw to move past and over said contour of said wrenched element;
• and,
• spring means urging said movable jaw to said extended position, whereby a ratcheting action is provided with gripping by said jaw wrenching faces with rotation in one direction and free rotation in the other direction;
• said means mounting said movable jaw to said wrench body including an arcuate jaw stem and an arcuate slot in said wrench body receiving said arcuate jaw stem, said jaw stem and said arcuate slot acting to guide said movable jaw to rotate upon rotation of said wrench body in a direction away from said movable jaw, to cause pushing of said movable jaw by engagement with said contour of said element to be wrenched, said arcuate stem thereby retracted into said arcuate slot, said jaw stem and slot configured to cause wedging of said jaw stem in said slot upon rotation of said wrench body in a direction towards said movable jaw to prevent retraction thereof from said extended position;
• said slot formed by concentric inner and outer walls comprising arc segments having a common center of radius of curvature thereof, said center of radius lying well within a quadrant of the wrenching space closest said wrenching body and said movable jaw.