GB753920A - Improvements in and relating to safety couplings - Google Patents

Abstract

753,920. Safety release couplings. BURKHARDT. G. May 14, 1954 [May 15, 1953], No. 14162/54. Class 80(2) A centrifugal clutch is interposed between the driving shaft and the clamping ring of a coupling of the type described in Specification 464,969 to cause release of the coupling upon overload. As shown, bushings 3, 4, fixed to the driving and driven shafts 1 2, respectively, may be axially slotted and are surrounded by a sleeve 5 with a tapered perimeter. Needle rollers are located in a slightly inclined position between the sleeve 5 and the clamping ring 8. Rotation of the latter causes it to move axially and clamp the bushes 3, 4 together. The degree of clamping is limited by the abutment of a nut 9 on the ring 8 with a flange 4b on the bushing 4. Pawls 11 and weighted members 12 are pivoted on pins 10 fixed to the bushing 3. At speeds below the normal operating speed springs 13 acting on the members 11, 12, keep the noses of the pawls 11 clear of teeth 14a formed on an annulus 14 fixed to the ring 8. If the torque exceeds the desired value slip occurs between the bushings 3, 4. If the pawls 11 are in the engaged position this results in relative rotation of the ring 8 and sleeve 5 to cause release of the clamping pressure between the bushings 3, 4. The coupling remains disengaged until reset manually. The bushing 3 may be in two parts 3, 3a interconnected by spiral springs 22 located in arcuate recesses 20, 21, in the two parts. The bushing 4 may likewise be in two parts 4, 4a, with similar springs therebetween.