Image Number 8 for United States Patent #4882979.
A fluid-powered actuator having a body with first and second end walls, with a bulkhead positioned therebetween, which is adjustably rotatable to angularly position the bulkhead relative to the body for fluid-powered operation to establish the end limits of rotation of an output shaft. The actuator has first and second piston heads disposed in the body on opposite sides of the bulkhead to define four fluid-tight chambers. In the preferred embodiment, the bulkhead is selectively clamped between two sidewall portions. A sleeve extends between and fixedly connects the piston heads together. A plurality of guide rods are fixedly attached to and extend between the piston heads and through apertures in the bulkhead in one embodiment, and between the first piston head and the bulkhead and through apertures in the first piston head in another embodiment to transmit torque to the body and through the bulkhead. An alternative embodiment has an eccentric piston sleeve projecting through a correspondingly sized and shaped aperture in the bulkhead to transmit torque. Seals are provided to prevent fluid leakage between the four fluid-tight chambers.