초록 ▼

A failsafe device, or pressure relief mechanism, for a shooting pot actuator in an injection molding machine. The shooting pot actuator has a multiple pusher rods mounted on one, or more, plates. Moving the plate holding the pusher rods depresses the shooting pot injection pistons and injects molten

A failsafe device, or pressure relief mechanism, for a shooting pot actuator in an injection molding machine. The shooting pot actuator has a multiple pusher rods mounted on one, or more, plates. Moving the plate holding the pusher rods depresses the shooting pot injection pistons and injects molten material into a number of mold cavities. To avoid damage to the machine from the pusher rods if an injection piston seizes, a failsafe device is used to mount the pusher rods to the plates. A shearing member is interposed, or sandwiched, between first and second apertures. Typically, the shearing member is a plate that, in normal operating conditions, blocks rearward movement of the pusher rod. However, when a predetermined shear force is applied to the shear plate, the shearing member shears and the pusher rod retracts within the channel, thereby alleviating the pressure. The failsafe device can be paired with a seizure detection system, using a laser beam, that detects piston and valve gate seizure, and provides appropriate notification or control signals.

대표청구항 ▼

[ We claim:] [1.]1. A failsafe device for a shooting pot actuator in an injection molding machine, the shooting pot actuator having a plurality of pusher rods mounted on a plate, the pusher rods abutting a respective plurality of injection pistons for injecting a molten material into a mold, the pla

[ We claim:] [1.]1. A failsafe device for a shooting pot actuator in an injection molding machine, the shooting pot actuator having a plurality of pusher rods mounted on a plate, the pusher rods abutting a respective plurality of injection pistons for injecting a molten material into a mold, the plate being driven to advance the pusher rods simultaneously against the injection pistons, comprising:means for mounting each pusher rod to the plate, the mounting means including a first aperture for receiving an end of the pusher rod, the aperture being aligned with a second aperture in the plate to form a channel for receiving the pusher rod;a shearing member interposed between the first and second apertures, the shearing member having a predetermined shear force which, if exceeded, causes the shearing member to shear to permit the pusher rod to retract within the channel.