Patent GB-128236-A (GB)
Title: Improvements in Mechanical and Electrical Relays.
IPC: H01H45/00
Filed: 1917-05-10
Abstract: 128,236. Barr & Stroud, Barr, A., and Stroud, W. May 10, 1917. Gyroscopic apparatus.-Relates to relay apparatus in which a small force or a small movement controls an external source of power so as to produce a comparatively powerful motion in a forward or backward direction. The invention is applicable, for example, for recording the movements of a galvanometer needle, for controlling " following " or " hunting mechanisms by a gyro-compass or a galvanometer, for enabling the gyroscope of a torpedo to control the steering-gear, or for enabling a gyroscope to keep a gun platform horizontal. In the form of the invention shown in Fig. 1, in which the movement of a galvanometer needle Q is recorded on a cylinder 8, a rotating drum A is engaged by a wheel K carried by a frame P pivoted at 1, 2 in a frame F pivoted at 3, 4 and carrying the recorder 7. While the plane of the wheel K is perpendicular to the axis of the drum A, the recorder 7 traces a straight line, but if the plane of the wheel K is tilted by the needle Q, the wheel K traces a helical line on the drum A and moves laterally together with the frame F and recorder 7. The axis 1, 2 about which the wheel K turns passes through or close to the point of contact of the wheel and drum. The wheel K may be replaced by a knife edge and the drum A by a disk. In the case of " following " or " hunting " mechanism, as in a gyro-compass, the frame F controls an electric or other motor which goes forward or backward until the parts P, Q are restored to their normal relative position. For this purpose the arrangements shown in Fig. 7 of Specification 15480/10, [Class 97 (i), Optical systems &c.], may be used. The wheel K may be used to make electrical contact as shown in Fig. 5, in which the wheel normally engages an insulating- section 42 of a rotating drum A, but when its plane is tilted by the member Q it moves to the right or to the left engaging one of the conducting-sections 41, 43, and these contacts effect the forward or backward motion of the " following- mechanism." In order to reduce the danger of the mechanism oscillating about its position of equilibrium, the motor may run slowly when the wheel K is on the insulating or central section, and quickly when on a conducting-section, contact between the wheel E and a conducting-section being arranged to short-circuit a resistance in the motor circuit. This principle may be extended by having several pairs of conducting- sections on each side of the insulating-section, large deviations of the wheel K cutting out more resistance than small deviations. In one form of " following-mechanism " the movement of the frame F varies the braking of double differential gearing so as to produce a movement of the following-mechanism in a direction corresponding to that of the frame F. In the arrangement described, the wheel K, Figs. 3 and 4, engages a disk A<1> forming the upper part of a toothed wheel 9 driven by a pinion 10 and shaft 11 carried by the following-mechanism. The shaft 12 of wheel 9 carries a spindle 13 having a bevel wheel 14 which continuously drives the bevels 15, 16 in the same direction. The bevels 15, 16 are secured to wheels 17, 18 respectively, wheel 17 gearing through an idle wheel 19 with a wheel 20, while wheel 18 gears directly with wheel 21. Wheels 20, 21, which are therefore driven in opposite directions, carry bevels 22, 24 gearing with a bevel 23 fixed to spindle 26 carrying pinion 27. The pinion 27 gears with a large toothed wheel 40 which is stationary. The whole of the mechanism shown in Figs. 3 and 4, except the wheel 40, is mounted on the following-mechanism, and any movement of the pinion 27 will carry the whole of the following-mechanism round the centre of the wheel 40. The wheels 18, 21 gear with wheels 30, 31 carrying fly-wheels 32, 33 engaged lightly by springs 34, 35 carried by the frame F. Thus the arm Q is moved by a gyrocompass, the wheel K will move laterally on the disk A<1>, and the consequent movement of the frame F will increase the braking effect of one spring 34, say, and reduce that of the other 35. The spindle 26 will, therefore, turn in a corresponding direction, and the whole of the following- mechanism will turn about the wheel 40 until the normal position of the parts Q, T is restored. When it is desired to transmit the indications to a distance, a commutator may be mounted on or geared to the spindle 26 to operate a step-by-step receiver.