GB691413A - Improvements in and relating to splined clutches - Google Patents

Abstract

691,413. Positive clutches. ENGLISH ELECTRIC CO., Ltd. Oct. 12, 1951 (Oct. 13, 1950], No. 25032/50. Class 80 (ii).. In a clutch wherein splines 1a with chamfered ends on a shaft 1, Fig. 1 (Prov), are to be engaged by axial movement of the shaft with splines 2a with chamfered ends in a sleeve 2, a ring 3 axially fixed on sleeve 2, but capable of angular movement thereon of less than half the spline pitch in either direction from a central position against the action of centering Springs 8, Fig. 2, has internal teeth 3a and carries a series of horse-shoe permanent magnets 3b, the alternating N and S poles of which are spaced at half the spline pitch and which co-operate with a corresponding series of magnets 5b carried by a ring 5 coupled for rotation with shaft 1. The arrangement is such that when engagement is attempted, if the splines 1a are not opposite the grooves between the splines 2a, as in Fig. 5b, the magnets 3b, 5b interact to produce an angular movement of ring 3 about sleeve 2, against the action of the centering springs 8, to bring the chamfered teeth 3a of ring 3, which has now reached the end of its movement relative to sleeve 2, into juxtaposition with the grooves between the splines 1a so that, as the engaging movement is continued; relative angular movement between the members 1, 2 is produced by the engaging force, allowing the teeth 3a and the splines 2a to be guided between the splines 1a. The ring 5 is axially fixed on a ring 6 which is splined on shaft 1 and which has an internal circular groove in which are arranged pairs of segments 7, Fig.-3. Springs 7a between adjacent pairs normally hold the members. of each pair in contact, as shown.in Fig. 3. The splines 1a are interrupted near their ends by a circular groove 1b so that teeth 7b on the segments co-operate with the end parts 1c of splines 1a to prevent withdrawal of shaft 1 from member 6 and the chamfered ends of teeth 7b co-operate with chamfered parts 1d of splines 1a so as normally to hold the member 6 relative to shaft 1 in the position shown in Fig. 1 (Prov). When shaft 1 is moved axially to the right, rings 5, 6 move with it until ring 5 abuts against ring 3. Thereafter, the chamfered parts 1d force the teeth 7b apart and into the spline grooves so as to allow the shaft to move through the segments 7. As shown, however, the ring 5 is angularly free on ring 6 and has internal teeth 5a. If now engagement is attempted with shaft 1 rotating relatively to sleeve 2, the friction between the members 3, 5 causes the teeth 5a to move into the position shown in Fig. 6b, in which any further axial engaging movement is prevented. Engagement is therefore effected with both members 1, 2 stationary. A brake for holding shaft 1, while allowing it to be turned a limited amount in either direction so as to permit clutch engagement, comprises brake shoes 12, 13, Fig. 1 (Comp), carried by a plate 11 journaled about the shaft axis and connected by a link 15 to an arm 16 secured to one end of a torsion bar 17, the other end of which is fixed. Specification 628,453 is referred to.