GB103936A - Safety Devices or the like. - Google Patents

Abstract

103,936. Root, C. F. June 14, 1916. Tripping and throw-out arrangements. - A safety-device and tripping-mechanism for printing presses is so arranged that, when a guard is moved by an obstruction such as the operator's hand, the plunger makes a short stroke at a reduced speed, but does not stop, jarring being thereby obviated. In the press shown in Fig. 1, a platen 4 and bed 3 both rock and come into contact in the plane of a yoke-shaped guard or controller 31 which telescopes the platen 4. A driving-link 11 is connected to the bed 3 by a pair of toggle-links 18, 19 normally held in line against a stop-pin by a spring 26<1>. The guard 31 moves vertically, being guided by a slot 33 engaging the end of a T-shaped lever 36. When the guard 31 is moved in either direction by an obstruction, the lever 36 is rocked and raises a lever 40 by either of two pins 37, 38. The lever 40 raises the end 45 of a lever 44, causing the other end 47 to release a gravity pawl 48, which then engages teeth 54 on an arm 51, holding it stationary for the remainder of the stroke of the link 11. This collapses the links 18, 19 as shown in Fig. 9, and stops the direct actuation of the bed 3, which, however, is advanced indirectly to a less extent by teeth 23, 24 formed on the link 19 and on the end of a rocking arm 25. On the return stroke, if the obstruction is removed, the guard is returned to its normal position by springs 43, 46, and the hooked end 55 of the arm 51 lifts the pawl 48, so that it is caught by the lever 44. An arm 59 on the guard can be turned into the path of the platen 4 so as to operate the tripping-mechanism at every stroke if desired.