Patent ID: 11951663
Assignee: DME COMPANY LLC
Field: Other special machines (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. An injection molding apparatus comprising:
a stack mold tool comprising:
a stationary mold block;
a center mold block movable between an open position and a closed position relative to the stationary mold block; and
a distal mold block movable between an open position and a closed position relative to the center mold block; and

a ball screw centering device comprising:
a center bearing housing connected to the center mold block;
a rotatable shaft extending through a channel of the center bearing housing and rotatably mounted to the center bearing housing, the rotatable shaft having a first side ball track and a second side ball track;
a first nut coupled to the stationary mold block, the first nut including a track portion cooperating with the first side ball track to define a passage for a first set of ball bearings to traverse;
a second nut coupled to the distal mold block, the second nut including a track portion cooperating with the second side ball track to define a passage for a second set of ball bearings to traverse;
a first nut housing fixed to the stationary mold block; and
a first sleeve connected to and extendable between the center bearing housing and the first nut housing to circumscribe an exposed portion of the first side ball track and an exposed portion of the first nut between the center bearing housing and the first nut housing, the first sleeve being positionable between an unexpanded position and an expanded position.