Abstract: A self-compensating support skate (46) for an annular hydraulic ram (15) mounted in the front stationary platen (10) of a “two-platen” injection molding machine (1) is disclosed. The hydraulic ram (15) fits into a central bore (22) in the stationary platen (10) and connects directly to a relatively thin die platen (11) that provides a mold mounting surface. The purpose of the skate (46) is to prevent movement (tilting) of the die platen (11) and the resulting misalignment with the movable platen (20) when the mold (30) is attached. The skate (46) is adjusted during assembly to compensate for the tolerance stack-up in the ram assembly. The “zero” clearance is maintained by disc springs (56) within the skate (46) that compensate for the expansions and contractions of the large diameter parts due to temperature variations. The die platen (11) is held in the aligned position by contact with the lower tie rods (7).

Abstract: A locking apparatus secures a movable platen in position relative to strain rods on which the movable platen is slidably carried. The locking apparatus includes split nuts that are carried by the movable platen and are pivotable about respective pivot axes between a first position in which the split nuts engage the strain rods and a second position in which the split nuts are pivoted away from the strain rods. The strain rods include grooved sections and the split nuts carry internal grooved portions that are complementary with the grooved portions of the strain rods so that the split nuts are engageable with the grooved portions of the strain rods to retain the movable platen in a desired position during a molding operation.

Abstract: A mold clamping system for molding articles by injecting a flowable material into a mold cavity defined by a pair of movable mold sections. The machine includes an hydraulically operated mold clamping system, and a separate hydraulic fluid reservoir for the hydraulic cylinder that provides the clamping force for holding together the mold sections during high pressure injection of molding material into the mold. The separate reservoir along with a lower, main reservoir permits a reduction of the overall height of the molding machine. The clamping system reservoir includes a level sensor, and a comparator is provided to compare the actual fluid level within the clamping system reservoir with the expected level based upon the position of the clamping ram, as sensed by a position transducer, to control the operation of an overflow valve when the actual fluid level is greater than the expected level.