Clamping unit operated by toggle lever mechanisms for an injection molding machine has toggle levers with offset joints which allow them to pass each other at the end of opening stroke

摘要

The toggle lever mechanism comprises two swivelling toggle levers(6,7) of identical length connected at one end to a fixed base and a moving platen(5) at the other. During tool opening freely moving joints(6.1,7.1) of the two toggle levers move towards each other in a swivelling plane. An offset of one swivelling plane relative to the other enables the two joints to pass each other in the final stages of a tool opening stroke. The length of the shorter lever(6,2,7.2) of each toggle lever(6,7) between the fixed points(1.1,1.2) and the freely moving joints(6.1,7.1) is greater than half the spacing of the two toggle levers in their extended position. Two identical toggle lever mechanisms are located at equal distances from a plane of symmetry between them. When two 5-point toggle lever mechanisms are employed a linear drive unit operating both is located on the fixed base and connected to the first lever of each mechanism. When used with a 7-point toggle lever mechanism a common linear moving intermediate platen is incorporated.