Abstract: A wheelchair having a structural frame, a first pair of front, ground-engaging wheels and a pair of fixed drive wheel assemblies, each including a hub is provided. The invention further includes a free floating handle or lever arm rotatably attached to at least one of the drive wheel assemblies. The lever arm engages the hub of each wheel drive assembly through the use of a friction engagement system, thereby enabling propulsive forces to be exerted on the wheelchair to propel the wheelchair in either a forward or rearward direction. The leverage thereby obtained is not limited by the radius of the wheel rim and the amount of leverage desired may be controlled by the user simply by placing the user's grasp at various locations along the lever arm. The lever arm and friction engagement system may also serve as a braking system for the wheelchair.

Abstract: A Toggled Breakout Wrench is described for use with a drilling rig having a drill stem made up of one or more drill pipe sections. The wrench comprises an arm movably connected to the drilling rig such that the arm will move in a substantially arctuate path about a drill pipe section. Pivotally mounted to the arm are a pair of opposed jaws for clamping about the drill pipe section to assist in breaking loose the threaded connections of the drill pipe sections. A toggle linkage enables the opposed jaws to move between a clamping and a non-clamping position about the drill pipe section.