Adjustable die closing unit for injection molding machine

Claim 1

In an injection molding machine having a knee linkage type die closing unit engaging a movable die carrier and a thrust stock with the end points of its knee linkage, thereby opening and closing the movable die carrier against a stationary die carrier which faces the former on the opposite side of the thrust stock, a device for fine-adjusting the longitudinal distance between the thrust stock and the stationary die carrier, comprising in combination: a generally flat supporting member carrying the thrust stock and the stationary die carrier; at least two parallel guide spars engaging and supporting the movable die carrier and extending longitudinally between the thrust stock and the stationary die carrier, whereby the latter serve as opposite guide spar supports; means for fixedly attaching the guide spars to one of said two guide spar supports; means for threading the other guide spar support longitudinally toward and away from said first-mentioned guide spar support; and wherein the threading means includes: a threaded length portion on each guide spar reaching through a guide bore in the associated guide spar support; an internally threaded adjustment member rotatably engaging each guide spar threaded length; means for rotating said adjustment members in synchronism; a recess in the guide spar support having opposing axial faces confining the adjustment members therebetween; means for axially clamping each adjustment member between the opposing axial faces of the recess, so as to block it against rotation; and means for also clamping the threads of each adjustment member against the guide spar threads, under the action of said axial adjustment member clamping means, so as to axially and rotationally block the mating threads against each other, thereby setting the position of the second guide spar support relative to the guide spar free of any operational backlash.