GB504019A - Advertising or display apparatus - Google Patents

Abstract

504,019. Changing signs. CHATFIELD, A., and SWIFT, O: P. Sept. 8, 1937, No. 24462. [Class 3(i)] In changing display devices in which an inclined translucent mirror reveals in turn an object disposed behind, seen directly, and an object in front of the mirror, seen by reflection the objects are illuminated with gradually increasing and gradually decreasing intensity. The means for effecting this comprises a rotary switch consisting of a disc 29 provided with contacts 33 and a conducting concentric annulus. The contacts 33 are joined together through resistances 34 which are carried by formers extending from the disc 29 to a lower ring 37, the disc and ring being held together by bolts and being rotated by an electric &c. motor 31. One of the contacts 33 is electrically joined to the annulus by a strip and a gap in the resistances is formed at the contacts 33 on the opposite side. The lid 11 of the switch box carries three spring buttons 43, 44, 45 which engage respectively contacts 33, the annulus and opposite contacts 33 when the lid is closed. Current is led to the annulus and reaches the two illuminating lamps of the sign by way respectively of a gradually increasing and a gradually diminishing number of resistances 33 as the disc turns. The upper portion of the rear surface of the inclined mirror is blackened or silvered to conceal the lamp which illuminates the back chamber.