PURPOSE: To assure the correct alignment state of parts and to prevent excessively early wear by providing a straight line shear mechanism which drives a shear blade assembly by utilizing a reciprocably movable rod of a glassware forming machine.

CONSTITUTION: This drive assembly is formed of arms 35, 37, 38, the driving rod 24, a drive means 28 far moving this rod 24 back and forth, etc. The arms 35, 37, 38 are fixed to the reciprocably movable mechanism of the glassware forming machine. The rod 24 is moved parallel relative to the mechanism described above and the arm 37. Further, the improved drive assembly has an improved joint 30 disposed between the arms 35, 37 and the rods 20, 24. This joint 30 is mounted at the rod 20. A radial spacing region 70 is formed between a peripheral member 42 and a bushing member 50 and a spacing region 80 is formed between the member 50 and an axiorthogonal plane. As a result, the arm 35 may be repositioned relative to the rod 20 within the limited range and may be directionally repositioned.