Accurate alignment of mould parts for synthetics - has one half located in approximate position against spring before closing mould on mating projection

摘要

The two halves of a mould for moulding synthetic materials have a projection and a recess which match and align the two halves. The movable half (1) is attached to a movable platen (3) in its basic position while the stationary half (2) is clamped to a stationary platen (4) in a provisional position where it can be moved sideways against a resistance. When the platens are brought together to close the mould, the stationary half is aligned as the projection and recess mate. The stationary half is then clamped in its final position. The provisional position of the stationary half can be determined by a clamp incorporating a helical spring to provide a resistance. A temp. differential between the two halves can provide the final alignment to lock them together. The upper half (2) can move slightly against the resistance of a helical spring (14) while the projecting rim (20) is aligned with the recess (17) along a guiding edge (19). The two halves (1,2) are then firmly clamped in position and the moulds heated to working temperature. For final alignment the stationary half (2) is raised by about 10 deg. C higher so that thermal expansion takes up any residual clearances. USE/ADVANTAGE - Gives very precise alignment of two halves of a mould, e.g. for making compact discs, without danger of damaging the moulds during closing or opening.