Abstract: A device for assisting in the opening and closing of a pivotally mounted member comprising an elongated housing having a closed end and an open end and an inner annular cylindrical space. An annular cylindrical slide having an inner and an outer end is slidably mounted in the space for longitudinal movement into and out of the housing and a spring centrally mounted between the housing and the slide retains the slide in the housing in a retracted position. Braking devices are provided for retarding movement of the slide in either direction that include nozzle-shaped orifices communicating the inner space with the outside of the housing so that air has to flow into and out of said orifice as the slide moves relative to the housing. Locking devices hold the slide in an extended position, the locking devices being releaseable by pulling the slide out of the housing a short distance, and journal devices are at the outer end of the slide for connecting the slide to a pivotally mounted member.

Abstract: A press for molding plastic materials wherein a stationary head and a movable head, arranged for receiving the two parts of a mold, are mounted on a base in which is installed a horizontal longitudinal member having pivoted at its ends vertical rocker levers. The upper ends of the rocker levers are connected to the stationary head and to the movable head respectively, and the lower ends thereof are connected to the ends of a hydraulic piston-cylinder assembly, which, thereby, applies to the heads a clamping force adequate to join the parts of the mold during the molding operation, without loading the base of the machine.