Patent GB-318903-A (GB)
Title: Improvements in electric luminous signs and signalling apparatus and their controllers
IPC: G09G3/00
Filed: 1928-05-04
Abstract: 318,903. Naylor, J. P. May 4. 1928. Monogrammic signs.-The electric lamps of a monogrammic sign are provided with parabolic reflectors and diffusing screens and are controlled for illumination by means of " templates " in the form of rods having conducting and non-conducting portions and rotatably mounted in carriers to bring them into operation seriatim. The lamps are arranged in series with one another and with various resistances which are also controlled by the templates so as to maintain the current in the circuit uniform. Lamps. In the form shown in Fig. 1 each lamp has a compact filament and is supported in an aperture 10 in the parabolic reflector 2. A diffusing cover glass 19 is removably held in place in the casing 18 ventilated by holes at 22. The lamp terminals are connected with terminals 7, 9 in a block 8 enclosed by a cap 11 screwed to the spigot portion of the reflector. The assembly is pivotally mounted on a plate 23 and may be adjusted angularly by a screw 17. The case containing a number of these plates 23 each pivotally adjustable and carrying a series of lamps may be provided with a coloured translucent panel and with ventilating holes. As an alternative the lamps may be mounted in a monoblock consisting of a porcelain bar 30, Fig. 6, formed with reflecting surfaces 33 and sockets 34 and having holes 32 to receive the assembling bolts. Circuit arrangements. Fig. 7 shows a number of lamps 1<a> - - 1<h> in series with one another and with resistances R<1>, R<2>, R<4> equal in value to one, two and four lamps respectively. The lamps and resistances are thrown into circuit and shortcircuited by brushes 37 bearing on non-conducting and conducting lengths 39, 38 of a " template. " Thus with the disposition illustrated lamps 1<b>, If and 1<h> and resistance R<4> are shortcircuited while the remaining lamps and resistances are in circuit. If a lamp becomes defective a coherer 44 consisting of aluminium particles coated with aluminium oxide breaks down under the electrical pressure and thus brings in a substitutional resistance 43. Templates. In the form shown in Fig. 8 a template consists of a rod 43a bearing, insulated from it and from one another, lengths of conducting and non-conducting material separated by non-conducting washers 40. If the electric supply is suitable for use with lamps in parallel the rod 43a need not be insulated from the conducting sections. The templates may be removably and rotatably mounted between discs 46, 47, Fig. 10, and the drum thus constituted may be stepped by ratchet mechanism to bring the templates one after another into co-operation with the brushes 37. In another arrangement the templates may be supported between the links of a pair of endless chains led over sprocket wheels and kept in position by weighted rollers in the bight of the chains. The links of the chains are offset stampings of the form shown in Fig. 13 and are assembled on connecting headed hollow studs 54, Fig. 14, in the rims of the bases of which are carried spring bows with radial ends 59, projecting through holes in the studs so as to engage grooves 55 in the ends of the templates when assembled. To prevent arcing as the contacts are broken, the main circuit includes a bridge piece attached to the reciprocating lever which carries the driving pawl for the template carrier so that while the template leaves the brushes 37 the bridge is lifted to interrupt the circuit.