GB1217512A - Improvements relating to machinery and drive means therefor - Google Patents

Abstract

1,217,512. Positive clutch control; machinery guards. J. A. McKAIN. 13 March, 1968 [15 March, 1967; 11 April, 1967; 3 June, 1967], Nos. 12050/67, 16411/67 and 25722/67. Headings F2C, F2J and F2L. In a positive clutch for a press wherein a clutch element 27 carried by a driven shaft 21 is spring biased into engagement with a driving wheel 24, a control sleeve 36 rotatable with the driven shaft 21 has a cam surface 47 or cam follower which co-acts with the clutch element 27 and moves the latter to a disengaged position when the control sleeve 36 is held by a pneumatically operated friction brake (55). As shown a radially slidable clutch key 27 is pressed by a spring 30 into a recess 29 in the driving wheel 24. A tension spring 41 normally rotates the control sleeve 36 with the driven shaft 21. When the brake (55) is applied to the control sleeve 36 continued rotation of the driven shaft 21 causes the clutch key 27 to ride down the cam 49 and disengage from the wheel 24. A pin 38 and slot 39 limits lost motion between the driven shaft 21, and control sleeve 36. On release of the brake (55) the spring 41 rotates the sleeve 36 relative to the shaft 21 until the cam slot 45 is aligned with the clutch key 27 to permit re-engagement. In Fig. 7 (not shown) an axially slidable clutch sleeve (82) splined to the driven shaft (21) is pressed by a spring (84) to engage teeth (83) on an end thereof with complementary teeth (81) on the wheel (24). A pin on the control sleeve (36) co-acts with a cam surface on the clutch sleeve (82) to disengage the clutch when the control sleeve is held by the brake (55). In Fig. 9 (not shown) an axially slidable clutch key (100) carried by the driven shaft (21) is pressed by a spring (101) into engagement with a recess in the wheel (24). A cam (102) on the control sleeve disengages the clutch key (100) from the wheel (24) when the control sleeve is held by the brake (55). In Fig. 10 (not shown) the tail (112) of a rotatable segmental clutch key (110), which connects the shaft (21) and wheel (24), coacts with a cam on the control sleeve to disengage the clutch. Interlock with guard.-A guard (Fig. 1, not shown), for the press is mechanically connected to a lever 63 carrying a projection 65. When the clutch is disengaged recesses 68, 70 in a flange 25 of the driven shaft 21 and control sleeve 36 are aligned and permit entry of the projection 65 during raising of the guard. Thereafter the projection 65 prevents clutch engaging relative rotation between the control sleeve 36 and driven shaft 21 until the guard is lowered. Initial movement of the guard may energize the brake 55.