Combination adjustable/lockable/measuring wrench, and methods of constructing and utilizing same

A wrench comprising:

• a head having a fixed first jaw;
• a second jaw movable in said head and having a rack;
• a shaft rotatably mounted in said head;
• a worm mounted on said shaft for rotation therewith and for meshing with said rack;
• means having a preset unlocked position and a preset locked position for selectively unlocking and locking said jaws in any desired position within the range of movement of said second movable jaw;
• said shaft and said worm being connected together as an integral unit so as to rotate together as an integral unit and to be locked together as an integral unit and to prevent any slidable movement between said shaft and said worm under all conditions and at all times;
• said shaft and worm being completely free to rotate as an integral unit when said means is in its preset unlocked position;
• said shaft and worm being locked together as an integral unit to prevent rotation thereof when said means is in its preset locked position;
• said means including a brake member operatively cooperating with said rotatable shaft, and a lever connected between said brake member and a translatable push button rod;
• said means being configured and arranged to permit operation of said means to its preset locked position and to its preset unlocked position by translation of said push button rod by the same hand of the user which is holding said wrench;
• and
• said brake member being actuatable, by operation of said lever caused by selective translation of said push button rod, to tightly frictionally engage said rotatable shaft to place said wrench in said locked position.