Patent GB-191304829-A (GB)
Title: Improvements in or relating to Electrical Order Transmitting Systems and the like.
Inventor: GRAHAM EDWARD ALFRED
Filed: 1913-02-25
Granted: 1914-02-19
Abstract: 4829. Graham, E. A., and Rickets, W. J. Feb. 25. Order apparatus. - A pointer can be set to three positions by shortcircuiting either or neither of the controlling-coils; and to two positions on either side of each of the former three, by the added effect of a second apparatus similarly constructed but contributing a smaller motion to the pointer. From a series of such apparatus, it is possible to obtain 3<n-2> different positions of the pointer by means of n connecting-wires. The main leads a, b, Fig. 2, are common to all the sets of apparatus such as f, g, &c., f<1>, g<1>, &c. ; and a separate signalling-lead such as c, c<1> is provided for each set. The transmitter A comprises a pointer x attached to and rotating with slip-rings u, t and adapted to be turned to definite positions by Geneva-stop mechanism operated by a handle, and brushes connected to the mains a, b are so arranged that when the transmitter pointer is at 1, 2, or 3, the line c is connected to the negative main via the slip-ring and contact v so as to short-circuit the coil g of the receiver B; while in positions 4, 5, 6, the line c is open and current flows through the coils f, g in series, and at 7, 8, 9 the coil f is short-circuited and g alone energized. With each of these three states of the line c may be associated any of three similar states of the line c<1>, for instance at 8 the line c<1> is open and the coils f<1>, g<1> are both energized; at 7 the coil g' is short-circuited through the line c<1>, slip-ring u, contact w, negative main, and conductor b ; while at 9 the coil f<1> is similarly short-circuited. In the form of receiver shown in Fig. 2, the coils f, g belong to motors, the spindles n, o of which are each capable of two positions; so that the gear-wheel p, the mounting of which is driven by differential bevel-gearing from the spindles n, o, takes up one of three positions according as either or neither of the coils f, g is short-circuited. The wheel k is geared level to the wheel p, and the wheel j is geared down from a wheel s controlled as above from the coils f<1>, g<1>. The receiver-pointer h is positioned by a spindle i the motion of which is compounded by means of differential bevel-gearing out of the motions of the wheels j, k. Thus the motors f, g produce three main positions 2, 5, 8 of the pointer; the motors f<1>, g' produce additional positions on either side of these namely, 1 and 3, 4 and 6, 7 and 9. In modifications, the pairs of coils such as f, g may be combined in a single three-position motor which positively controls a wheel, such as p, as for example in the form shown in Fig. 5. Here the poles 16, 19 and the rotatable three-position armature 17 are constantly energized and the coils f, g are wound together on the poles 13, 14 so as to neutralize one another when the line c is open, the armature being then vertical. When, however, one of the coils f, g is short-circuited, the poles 13, 14 are energized and the armature is turned. The poles 16, 19 may, in the lateral positions of the pointer, be de-energized by means of a relay, the armature 17 being then independently wound. In further modifications, the coils f, g may be wound on two or more separate poles, these windings and that of the armature being arranged in various suitable ways. In a form with two supply wires and three signalling-wires, giving twenty-seven positions of the pointer, one pair of coils f, g is wound on poles 13, 14, as shown in Fig. 5; a second pair is wound on the armature; and a third pair is wound on eight subsidiary poles produced by bifurcating the poles 13, 14, 19, 20. The poles energized by the windings f, g, &c. may rotate, the armature 17 being stationary. In a different form of the invention, the first motor turns the second motor as a whole, and the second motor contributing a smaller angular movement turns the pointer. The apparatus may be used with either alternating or direct current,