Torque Overload Safety Device for Clutches

摘要

1,180,357. Clutch control. KELLER & KNAPPICH G.m.b.H. 4 Oct., 1968 [21 Nov., 19671, No. 47101/68. Headings F2C and F2L. A pneumatically operated friction clutch 6 is disengaged on overload detected by relative rotation between the inner and outer sleeves 10, 12 of a resilient coupling 11 in series with the clutch 6. The resilient coupling comprises a rubber annulus 11 between the sleeves 10, 12 which are respectively fast with a sleeve 9 driven by the clutch output shaft 8 and a driven sleeve 13. A pin 14 fast with the sleeve 13 engages a helical slot 15 in a sleeve 16 and a drum 18 fast with the sleeve 9 carries a pin 17 engaging an axial slot 19 in the sleeve 16. On overload, relative rotation between the sleeves 9, 13 causes axial movement of the sleeve 16 which closes a switch 20 to energize a solenoid 21 that actuates a valve 23 to vent pressure air from a clutch servo cylinder 4 whereupon a spring 25 disengages the clutch. The maximum permitted torque may be adjusted by varying the position of the switch 20 relative to the sleeve 16.