GB351572A - Improvements in light signals and in and relating to light signal systems - Google Patents

Abstract

351,572. Signal lamps. BRITISH POWER RAILWAY SIGNAL CO., Ltd., GLENN, S. L., and PIERCE, E. E., Windsor Works, Slough. Nov. 17, 1930, No. 1781. [Class 75 (iv).] Relates to signalling apparatus producing coloured beams of light for the control of road traffic, and is applicable also to railway signalling, airport and marine signalling, and code signalling. Around a single source of light 52 rotates or oscillates a turret 8 carrying eight glass plates 31 .. 38 of appropriate colours, alternate glasses being screened while the remaining glasses transmit beams through the double lens systems 130, 9 in a fixed housing 7. A hinged lid 57 renders the multi-filament lamp 52 easily accessible. The glasses 31, 33, 35, 37 are amber, 32, 36 red, and 34, 38 green, so that oscillation of the turret forty-five degrees to either side of the position shown in Fig. 4 gives the desired signals for traffic control. This oscillation is effected by an electric motor 21, the signal being automatically returned to the amber position by a mechanical device comprising a disc 60 on the motor shaft 20. As soon as the motor is deenergized a weighted arm 63 or 64 bearing on a roller 61 or 62 on the disc 60 restores the signal to amber. Other devices may be used for this purpose, for example, cams and counterweights, torsion springs, magnets, or air or liquid siphons. A flywheel 71 is frictionally mounted on the shaft 20. The turret 8 may be arranged to rotate unidirectionally by steps to give the necessary indications. The motor shaft may be damped by notching the surface of the armature along its axis and correspondingly notching the surface of the field poles. The armature may also have a damping winding of known form. Direct manual control may be provided for by a handle 72 and a clutch device 78, another clutch 85, releasable by a handle 82, being provided to hold the handle 72 in the engaged position after it has been forced in. Instead of an instantaneous change of colour, there may be a two-colour beam shown for an intervening period. An independent quadruplex aspect for giving the amber signal alone may be mounted above the signal unit in the same housing. In place of a single quadruplex signal, simplified units each with one clear double lens system only may be used at each street of the crossing. In a modification the turret has coloured sectors arranged vertically, the turret being moved up and down to bring the desired coloured screen to the focus of the lensing system.