GB210355A - Improvements in electrical control for mechanisms for setting or displacing a tool or other device by a predetermined amount - Google Patents

Abstract

210,355. August, J. R. C., and Hunter, E. K. Sept. 15, 1922. Gauging-devices; indexing. -In an electrical control arrangement for a setting mechanism for displacing a tool or other device to a predetermined amount such as that described in Specification 200,127, the tool &c. which is normally locked to a stationary element is first connected to a movable element, then disconnected from the stationary element and finally, after partaking of the movement of the movable element, is again connected to the stationary element before being disconnected from the movable element. The carriage 18 to be displaced may be coupled electromagnetically either to a fixed member 20 or to a spindle 17 which is reciprocated accurately between set limits by means of a setting device comprising a number of cam elements 15 loosely arranged between a fixed abutment 97 and a collar on the spindle 17 and having cam projections provided with accurately ground spacing parallel ,surfaces 23, 24. The sleeves 15 coact with sliding bushes 16 having pins 25, each sleeve with its bush forming an element capable of expansion in length by the distance between the surfaces 23, 24. The sleeves 15 are rotated bv means of feathered six-toothed ratchet wheels 13 operated by pawls mounted on a spindle carried between end flanges 2, 3 which are constantly oscillated from a shaft 8. The pawls are brought into engagement with their ratchet wheels by means of electromagnets 5 mounted on a bridge-piece 4. The energizing of the magnets is controlled by a number of drums 99, 100 each having six segments of different lengths adapted to co-operate with brushes 102 mounted on levers 103 which are normally held against the commutator surfaces by springs. By means of cams 106 the levers 103 are lifted once for each revolution of the drums into the range of a locking catch 108 and are withdrawn on energizing the magnets 110 to free the brush 102 so as to energize the desired magnet 5. A master switch drum 111 rotating at six times the speed of the drums 99, 100 &c. is provided with overlapping contact strips one of which operates the magnet 21 while the other operates magnet 19. Thus for each revolution of the drums 99, 100 the spindle 17 may be displaced by any amount between unity and six times the sum of the distances between the spaced parallel surfaces on the sleeves 15. These distances are arranged in the geometrical series 1, 7, 49, 343 - - - in which the ratio is one plus the number of commutator segments. The circuits of the magnets 110 are controlled by keys which are numbered in units of displacement as shown in Fig. 13.