Abstract: The disclosure concerns a continuous mixer for plastic material and of the type which permits control of the pressure on the material being mixed in the mixer by resisting the flow of mixed material displaced from the mixer when unmixed material is fed into the mixer. The resistance to the discharged flow is effected by one or more elements which engage the flow and which are movable.

Abstract: The assembly includes a sidewall and bead plate ring mounted on a lower bladder hub plate in a press to extend generally radially therefrom for engaging the lower half of a retread matrix which is centered thereby, and a matrix register and centering ring is provided for attachment to the lower press platen after being moved into centering engagement with the lower matrix half whereby the matrix half can be removed from engagement with the said centering ring and then be replaced in centered relationship to the press by engagement with the centering ring.

Abstract: A calender especially suitable for use with rubber and plastic material. One of two opposed rolls is movable toward and away from the other through direct action of long-stroke fluid actuators that move the bearing boxes on opposite ends of the movable roll. Roll spacing is directly sensed by position-sensitive transducers acting between opposed bearing boxes and responsive to the relative roll positions. The transducers signal changes and initiate correction to retain roll spacing at a set distance. The fluid actuators are controlled to separate the rolls upon power failure and to prevent roll contact in the event work product is not between the rolls.