GB585680A - Improvements in guards for presses and similar machines - Google Patents

Abstract

585,680. Machinery guards. BROUGHTON, G. J. Jan. 26. 1944, No. 1440. [Class 80 (iv)] In presses and similar machines a pair of brackets 10 on the machine frame carry a rotatable shaft 11 on which are pivoted side bars 12 which are prevented from being swung away from the machine either by a bolt 13 or a releasable clip. The side bars are connected together by horizontal rods 15 which leave a space 16 through which the operator can obtain access to the machine table. The guard proper comprises an upper frame 19 fixed on a shaft 18 rotatably carried by the bars 12 and having pivoted on a rod 21 at its lower edge a lower frame 20 comprising two side members 23 the lower rods of which are connected by a rod 24 whose ends are slidable in guide slots 25, Fig. 1, in the bars 12, the guard being closed by pulling down this rod. When open, both guard members extend inwardly as in Fig. 1. When released, the guard is opened by a spring 27 acting upon an arm 26 on shaft 18. An arm 29 secured to shaft 18 is connected by a link 30 to an arm 31 pivoted on shaft 11, and fixed on this shaft is another arm 32 carrying a scotch 33 adapted to enter a notch 34 in a disc 35 on the end of the crankshaft. The arms 31, 32 are normally locked together by a spring-pressed pin 36 engaging a hole in arm 32. At the other end of the shaft is an arm 37 which, when the guard is open, prevents engagement of the clutch. Moving the guard to closed position brings the scotch out of the notch 34 and allows the clutch to be engaged. While the machine is running, the contact of the scotch with the periphery of the disc prevents opening of the guard. The machine comes to rest after one revolution with the scotch brought again into the notch by the spring 27. In a modification, the side bars 12 are bent rearwardly and the arm carrying the scotch is secured to a shaft carrying an apertured plate to control clutch movement. Further, the shaft 11 may be provided with an arm carrying a stud adapted to engage the machine frame and prevent backward movement of the side bars.