Patent GB-428791-A (GB)
Title: An improved vehicle head lamp
IPC: B60Q1/14
Filed: 1933-11-20
Abstract: 428,791. Vehicle, aerodrome, &c. lamps. MACLEOD, H. C. C., 121, London Road, Leicester, and CLARKSON, A. H., 134, Boston Avenue, Southend-on-Sea. Nov. 20, 1933, Nos. 32281/33 and 3109/34. [Class 75 (iv)] A lamp, particularly applicable for use on a vehicle or for lighting an aerodrome, comprises means for projecting forward a slightly downwardly inclined beam of light and a tier of louvres adapted to screen the light source and reflector from direct frontal vision, and so arranged that a portion of the downwardly inclined beam passes between them without interference while the remainder is intercepted and diverted downwards at a steeper angle. The parts of the lamp may be fixed in the above positions or they may be movable to and from a position in which the beam is projected horizontally without obstruction. The louvres may be made of thin stainless steel with their upper surfaces dulled or blackened and their lower surfaces plated with silver or chromium or otherwise made reflecting, and preferably broken up so as to diffuse the light. In the screening position the rear edge of each louvre is substantially level with the front edge of the louvre immediately above it, and means may be provided for increasing the intensity of the light source when the louvres are in the screening position. In the form shown in Fig. 1, the louvres 15 are carried by a ring frame 13 which is pivoted on trunnions 14 and connected by a link 17 and universal joints 19, 18 to a reflector 11 which is pivoted about trunnions 12, so that a slight tilting of the reflector produces a greater tilting of the louvres. The link 17 may be adjustable for length. In a modification the louvres are mounted for movement in unison about individual axes. In the form shown in Fig. 3, the trunnions 12 are carried by a ring-like cage 21 to which is attached a rearwardly directed stirrup 24 carrying an electromagnet 25 adapted to tilt the reflector against the action of a spring, (not shown). A plunger 27 engages an arm 26 which projects from the reflector through an aperture in the stirrup, movement of the reflector being limited by another projection 28 engaging a resilient buffer 29 on the stirrup. The normal bezel ring is replaced by an adaptor 32 carrying a cover glass 16 (or the front of the adaptor may be constructed to receive the normal bezel ring), and fitted with a cage 34 for supporting the ring 13. A lever 42 is pivoted at its lower end upon a lug 43 carried by the lamp casing 10, its mid point is pivotally connected by a link 45 to the reflector 11, and its top end is pivotally connected by a link 44 to the ring frame 13. The link 44 may be adjustable for length. The frame 13 carries the ball 46 of a separable ball and socket joint, one half of the socket of which is integral with the link 44 whilst the other half is formed by a cup movable in the end of the link and pressed towards the first half by means of a spring, so that the joint may be broken by pulling on a finger piece 47. Access to this finger piece is obtained by means of a movable cover plate 36 which closes an aperture in the adaptor 32. A screw 37 is carried by a trunnion block 38 pivotally mounted in lugs 39 on the lamp casing, extends through a lug on the cover plate, and its front end passes through a forked lug 40 on the adaptor and is engaged by a locking nut 41. Alternatively, the louvres may be carried by the lamp casing and left in position when the adaptor is removed. Details of means for mounting the louvres in the ring frame or other supports are given in the Specification. According to the first Provisional Specification the louvres may be slightly inclined across the lamp front so as to reflect light towards the near side, and they may be mounted in a rectangular frame.