Press with swingable top press plate

Abstract

A mold press for an electric drive arrangement for controlling opening and closing press movement. The drive arrangement includes a pair of generally identical drive units connected between upper and lower press plates. The drive units in a preferred embodiment each employ a ball-screw arrangement. A screw shaft extends vertically of the press, and engages a ball nut assembly which is mounted on the top press plate for effecting movement thereof toward and away from the bottom press plate. An electric motor is coupled to the screw shafts for effecting high speed opening and closing movement of the top press plate. A force apply device, such as an inflatable hose or bladder, is associated with the bottom press plate to effect application of the desired press closing force. A control linkage is connected between the top press plate and the frame for effecting automatic sideward swinging of the top press plate between a side access position when the plate is in its fully opened position, and an operational position wherein the top press plate is disposed vertically aligned above but spaced upwardly from the lower press plate. The swinging movement of the top press plate between these two positions is effected automatically in response to vertical displacement of the top press plate by the main drive unit during an upper portion of the normal opening and closing movement of the top press plate. This control linkage, in a preferred embodiment, comprises a self-contained extendible spring device such as an air spring which effectively assumes a minimum height position when the top press plate is intermediate its stroke so as to induce sideward swinging of the top press plate during the upper portion of the stroke.