Glass gob shearing apparatus with improved cushioning of shear blade

Abstract

A parallel shear apparatus for sequentially shearing each of a plurality of streams of molten glass from a glass feeder into gobs for processing into glass containers by a glass forming machine. The apparatus has first and second opposed carriages which are reciprocable along parallel slides toward and away from one another, each of the carriages carrying one or more opposed knife elements, corresponding to the number of streams of molten glass, and the opposed knife elements overlap at the innermost limits of their travel to perform the shearing action. Motion of the carriages is actuated by a unidirectionally acting servo motor, which imparts oscillating motion to a bell crank through a connecting rod. The oscillating motion of the bell crank imparts simultaneous, opposed, rectilinear motion to the carriages through connecting rods, which are pivotally attached to the servo motor at diametrically spaced apart locations. The servo motor is mounted on a pivoting bracket that is urged to its normal operating position by a pneumatic cylinder and is spring biased away from its normal operating position in the event of a stoppage. The pneumatic cylinder is cushioned to minimize shock loads caused by a sudden retraction of the servo motor mounting bracket and is adjustably mounted relative to fixed structure of the shear apparatus.