Abstract: A tool holder of the two-jaw type is provided which has the centering accuracy and gripping power of a three-jaw geared chuck. The tool holder includes a body having ways formed by a polygonal passageway which is perpendicular to the central axis of the tool holder body. The jaw mechanism includes a differential screw which mates, on one end, with the body of the tool holder and, on the other end, with a pair of anvil pieces. The face of the differential screw and the anvil pieces move toward and away from the central axis of the tool holder along the ways formed by the polygonal passageway and provide the tool-gripping means.

Abstract: Process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine are provided. The process provides a compression release event for each cylinder during each revolution of the engine crankshaft. In accordance with the process, the normal motion of the exhaust and intake valves is inhibited and the exhaust valves are opened briefly at each time the engine piston approaches the top dead center position. The intake valves are opened after each opening of the exhaust valves. The apparatus includes hydraulic means driven by the engine pushtubes which produce a timed hydraulic pulse adapted to open the exhaust and intake valves at the proper time. Hydraulically actuated means are provided to disable the valve crosshead or rocker arm so as to inhibit the normal motion of the valves. Alternatively, timed signals from an electronic controller actuate solenoid valves to control a hydraulic pulse which opens the valves.

Abstract: A pressure relief system for an internal combustion engine compression relief engine brake is disclosed. The pressure relief system comprises a bi-stable ball relief valve associated with the high pressure hydraulic system together with damping means adapted to damp out rapidly the oscillations of the ball valve during the period of its opening so as to maximize the flow of hydraulic fluid through the bi-stable valve and minimize the time required to relieve the pressure in the high pressure hydraulic system of the compression relief engine brake. The damping means comprises a spring controlled ball valve guide which inhibits premature reseating of the bi-stable ball valve and maximizes the average opening of the valve during its operating period.

Abstract: A gear and boss protector for the spring driving mechanism of a tap selector such as a voltage regulator. A pair of hook cams form the protective means and they are mounted rotatably on the crank driven by the spring driving gear. One of the hook cams engages the driving boss on the driving gear should the gear reverse rotation in one direction, while the other hook cam engages the driving boss on the driving gear should the gear reverse rotation in the opposite direction. The engagement of the driving boss by the hook cam prevents the crank from being suddenly released causing damage to the gear or boss.