Abstract: A wrench having two separate jaw arms, at least one jaw member on each said arm, and a sliding cam engaging the two arms, so that the two arms can be adjusted together or apart while maintaining the respective jaw members in a precise parallel relationship, and in which the cam engages both the jaw arms simultaneously.

Abstract: A wrench having two separate jaw arms, at least one jaw member on each said arm, and a sliding cam engaging the two arms, so that the two arms can be adjusted together or apart while maintaining the respective jaw members in a precise parallel relationship, and in which the cam engages both the jaw arms simultaneously.

Abstract: In a nutating spherical engine, improvements for increasing the seal between the rotor and the engine head comprise the provisions of a pair of minor cusps disposed on the rotor which as seen in plan view are diametrically opposed and at right angles to the major cusps of the rotor. The engine may include a rotor guide including a cam and cam follower which cause the rotor to undergo the same nutational rotation as that caused by the interaction of the rotor and cylinder head. The rotor and cylinder head may be coupled by a ball and socket, and the ball may contain a simple coupling for the drive shaft of the engine. The cam, cam follower and coupling of the engine are easily located as they are not in direct communication with the working chambers of the engine.