US2481269A - Control system for electric signs - Google Patents

Description

T. R. WELCH 2,481,269

CONTROL SYSTEM FOR ELECTRIC SIGNS 4 'Shee'ts-Sheet 1 INVENTOR. THOMAS ROSS WELGH 'A-TTORNEY Sept. 6, 1949.

Filed Dec. 26 1946 Sept. 6, 1949. T. R. WELCH 2,481,269

CONTROL SYSTEM FOR ELECTRIC SIGNS Filed Dec. 26, 1946 4 Sheets-Sheet 2 INVENTOR.

THOMAS ROSS WELCH 7 ATTORNEY Sept. 6, 1949. T; w c 2,481,269

CONTROL SYSTEM FOR ELECTRIC SIGNS Filed Dec. 26, 1946 4 Sheets-Sheet 5 INVENTOR.

THOMAS. ROSS WELCH m AC. INPUT ATTORNEY Sept. 6, 1949. T. R. WELCH CONTROL SYSTEM FOR ELECTRIC SIGNS Filed Dec. 26, 1946 4 Sheets-Sheet 4 B It: 4 4

| |||.l.|||| IT'II .IIIII THOMAS ROSS WELCH INVENTII ATTORNEY Patented Sept. 6,

UNIT ED S TAT ES 01F F [C E1 2,481,269 common sits-31cm Foaatacraic SIGNS Thomas Ross Welch, lbosAngeIes, Gal-if;

Application December 26, 1946, Serial No..7 18,433

8 Claims. (Cl. EFF-3'50) The present invention relates generally to signs of the type in which pre-selected characters or symbols of a desired message may be caused to appear in successive order so as to visually impart the message to an observer, and is more particularly concerned with improvements in the control system for such signs.

Briefly, a sign and control system, embodying the features of the present invention comprises a plurality of symbol formers arranged to be successively changed as a group to display a desired message or portion of a message consisting of words, letters, numerals and the like.

The particular symbol or character displayed by each symbol former during the successive group displays is determined by theme-setting of a plurality of symbol selectors associated with each symbol former, and which are arranged to be successively energized. All the symbol selectors for a given symbol former are simi arly connected to a set of common conductors leading to the symbol former, and all successive group changes for that particular symbol former are accomplished over this set of common conductors.-

Undesired sneak or back circuits through portions, of those common conductors and symbol selectors which are not being utilized for the group of symbolsv on display, ispreventedby the utilization of one-wayvalves or rectifiers in such a manner as to confine current flow to the, proper circuit paths.

It is a characteristic of this type of valve or rectifier that they will occasionally break down and permit current flow in a reverse direction, In other words, they may fail to actv as valves for the confining of current flow to a desired'flow path. This condition, however, is readily remedied by subjecting the valves to reversed polarity. The means for accomplishing the connection of reversed polarity to the rectifiers constitutes a feature of the control system of" my present invention, which will be described. subse quently in greater detail.

Having the foregoing in mind, ltis a primary object of the present invention to provide an improved control system for display signs of. the herein described type, which is economical of installation, efficient in operation. and whichv may be easily preset to produce diilerent messages anddisplays, as desired.

A further object of the invention, is to pro vide novel control whereby the valves or rectifiers of the system may be subjected to'reversed polarity during periods of non-use in order to decrease the possibility of break-down and restore those rectifiers which may have broken down during operation, without the necessity of having to stop, the sign operation or interrupt its continued operation in any way.

Further objects of the invention will'be' brought out in the following parts of the specification wherein detailed description is for the. purpose or'iully disclosing preferred embodiments of the invention without placing limitations on the scope of the invention definedin the appended 3: claims.

r eierring to the drawings whichare for illustrative purposes only:

Fig. i is a combined wiring diagram andschematic perspective view generally illustrating the principal components of a sign embodying the control system or the present invent-ion;

Fig. 2-is a front view ofa symbol selector receptacle as utilized therein;

Fig. 3 is a sectional view, taken substantially on line 3'-3- ofFig. 2;

Fig: 4 is a front viewer a symbol selector plug;

Fig. 5 is a sectional view through the plug, taken substantially on line 5"5'10f'Fig; 4;

Fig. 6 is adetailed wiring diagram and a sch-e- Inatic plan view' of' a symbol formerand associated devices;- and Fig; lis a fragmentary wiring diagram illustrating circuit connection detailsfor the entire control system.

Referring now to the drawings, the presentin- Vention is therein illustrated as generally comprising a sign Ill, as'viewe'd" from the rear, which my be located on the top" of-a building or in" other prominent position for the visual display of characters; numerals; or other indicia con.- stitutinga message; This sign which is of the changeable type; as will be described subsequently in detail; is interconnected with a control or program panel as generallyindicated at l i \vhich'may be remotely located with reference tothe sign in any desired location within the building. The control-panel isin turn connected with remotely located power-supply apparatus as generallyindicated at' [2 which may be located in the basement of the building; or other desired location.

The sign- It comprises a plurality ofidentical symbol former-s I3 assembled? in aligned relation for the individualformation and'displayof characters; symbols, or the like of the message tobe visually displayed by thesign;

The details ofthe construction of the symbol former-are-shown in Fig. 6; Each symbol-former is composed of aplurality of illuminable; tube sections= M to-2ll ,'inclusive-, which are interconnected toform a series electricalclrcuit supplied from the secondary winding of a suitable supply transformer 2 I.

The tube sections are respectively formed from glass tubes, filled with suitable gas and provided with electrodes intermediate their ends for enabling all or a part of each tube section to be illuminated. In practice, these tubes may be of the neon type. The tubes are positioned and variously formed so that when selected portions thereof are illuminated, the illuminated sections combine to compositely form a desired symbol or character.

As an example of the manner in which each tube section is broken down into illuminable portions, it will be noted that the tube I9 is divided into interconnected portions by spaced electrodes therein, eight portions being provided. Adjacent electrodesfor example, electrodes as indicated at 2la and 2| b at the top portion of the tube I9-are interconnected by a bridging conductor 22 having control contacts 23 therein which are operatively associated with operating coil 24. By means of this switch, the portion lying between adjacent electrodes may be controlled as to its illumination or non-illumination. The contacts 23 are of the normally closed type so that initially all the tube portions are bridged and consequently rendered non-illuminable. It will be apparent that by selectively energizing the operating coils 24, the illumination and non-illumination of the portions of the respective tube sections may be controlled to form the desired symbols or characters. In order that flexible control may be accomplished, one side of each coil 24 is connected to a common conductor 25 and the other side of each coil is connected to an individual control conductor 26. The conductor 26 for each symbol former is carried through a common cable 21 for association with symbol selectors at the program panel, as will hereinafter be more fully described in detail.

Each symbol former is interconnected through its conductors 26 in a similar manner to a plurality of symbol selectors arranged in a vertical bank 28 for successive energization to cause successive characters as determined by the symbol selector to appear on the associated symbol former of the sign. The symbol selectors for all the symbol formers are horizontally aligned and interconnected to form groups 29, whereby the symbol formers of the entire sign will be activated as a group for each successive change thereof. The respective groups of symbol selectors are energized through common supply conductors 3ll-3ila3ilb, etc. All these conductors may be contained in a single interconnecting cable 3| extending to the power supply apparatus I2.

The symbol selector may be of the type disclosed in my copending application covering a Visual signal program system, Serial No. 694,664, filed September 3, 1946, or it may be as particularly disclosed in Figs. 2, 3, 4, and herein. Referring to Fig. 3, the program panel is provided with a front panel board 32 having a plurality of holes or openings 33 therein arranged to form the mounting positions for the vertical banks 28 and horizontal groups 29 of symbol selectors, as shown in Fig. 1. Each symbol selector is composed of two parts, namely, a receptacle assembly 34 and a plug assembly 35.

The receptacle assembly comprises a tubular casing 36 having an integrally formed flange 31 adjacent one end, by means of which it may be mounted in an opening 33 with the flange extending over the rear surface of the panel board.

The receptacle may be secured in operative position by means of suitable screws or other securing members connecting the flange with the panel board. The rear end of the tubular casing may be closed by a bottom member 38 which may be apertured for supporting connection wires passing to the receptacle interior. A plurality of pin receiving sockets 39 are supported in a disc 40 of insulating material, these sockets having their open ends facing the front open end of the casing 36 and being spaced relatively as shown in Fig. 2 of the drawings.

Referring now to Fig. 5 of the drawings, the symbol selector plug 35 is shown as comprising a disc shaped base member 41 of suitable insulating material having a plurality of contact pins 42 set therein with their ends similarly projecting beyond the base member and correspondingly located and spaced to correspond with the positioning of the pin receiving sockets 39. Suitable means (not shown) are provided for orienting the selector plug relative to the selector socket so that the same pins will always go in the same socket each time the plug is inserted. The base member 4! of the plug assembly is provided with a cup shaped cap 43 which is partially inserted over the opposite side of the base member from that in which the pins 42 project. This cap member cooperates with the base member to define an interior space or cavity 44 within which connection may be made between certain of the pins in the plug for a purpose hereinafter to be described more fully. As shown, however, jumper connections 45 in this space are utilized for interconnecting certain pins of the upper part of the plug with other pins of the lower part of the plug. These jumpers are so arranged that interconnections are established with the control conductors 26 to the associated symbol former so as to determine the character which will be displayed. This character, for convenience, is indicated on the outside of the bottom of the cap 43, and, in this case, constitutes the letter A as shown in Fig. 4 and indicated by numeral 46.

As shown in Fig. 3, the upper five rows of the pin sockets total twenty-eight in number and correspond to the total number of operating coils 24 associated with each symbol former. Moreover, each of these sockets is connected by a control conductor 26 with one of the coils. The remaining sockets in the lower half of the receptacle 34 are utilized for connecting the desired. pins in the upper portion of the receptacle with a supply circuit by means of jumpers 45 to give the appropriate selectivity in the signal former to form the proper display characteristics. The sockets in the lower portion of the receptacle 34 are respectively provided with valves 4'! for limiting the direction of flow of current through their associated sockets in one direction only from a common conductor such as a common supply conductor 30.

Referring to Fig. 7, the various elements of the system have been more or less diagrammatically represented and is restricted to the first three symbol selectors of a vertical bank 28 associated with one of the symbol formers. It is thought, however, that the description in this connection will be clearly understood and fully illustrate the operation of the other components of the system.

Current for the energization of the operating coils 24 for the contacts 23 of each symbol former is supplied from a bridge connected rectifier '48. Provision is made for selectively connecting the common supply conductors 30, 30a and 30b to the positive polarity side of the-rectifier. 48 and to the sideof rectifier 4 8a; these two rectifiers be, ing series-connected-with their common interconnection connected-to common conductor 25". The foregoing is accomplished by means of a plurality of electrically actuated switches 49, each switch having normally closedcontacts 5U. for connecting the common suppl conductors of thev symbol se lectors to the negative side of the rectifier 48a, and normally open contacts 5| operable to connect the common conductor tothe positive-side of the rectifier 48 when the operating coil 52 of. the switch is energized.

A- switch 49 is thus: provided to control theene ergization of the feeder conductor for each group, 29 of symbol selectors, and provisionis made for successively energizing. the operating coils. 5?; of the switches in timed sequence. For; such purpose, oneside oi the operating coils 52 areccmmonly connected to a conductor 53 of an alterhating current supply circuit, and the other side of these coils 52 are respectively connected withstationary contacts 54 of a stepping switchgenerally indicated by the numeral 55. This switch is provided with a rotating contact 56 arranged to successively engage the stationary contacts 54. The rotating contact has electrical connection with a conductor. 51 which constitutes the other side of the supply circuit. Periodic movement of the contact 56 is accomplished by means of a pawl and ratchet mechanism 58. operatively associated with an actuating coil 59, having one terminal thereof connected'tothe conductor 53; and its other terminal connected to the conductor 51 of. the supply circuit through the contacts 5B,. of a cam switch iii. The cam switch 6| isdriven ata constant speed by a suitablemotor 62 having its terminals connected to the, circuit conductors 53: and 51. g

The primary winding of thetransformer 2|, located at the sign, issupplied overa pairof con.- ductors 63, which may be grouped in a single cable as indicated at 63a, and connected directly to circuit conductors 53 and 51'; or througha cam operative switch 64 by means of a selector switch 64a. The switch 64 is normally closed; and, is arranged to open in p-redetermined time relation to the actuation of the switch 64, being driven also by the motor 62. More specifically, the switch 64 opens to deenergize the sign before the switch 5| closes to successively connect the, next group of symbol selectors. The switch 64 again closes to energize the sign, and thereafter the switch 6| again opens the circuit preparatory to shifting to the next group upon the next closure of the switch 6 I tart-mg and stopping, of thesign and its control system is accomplished through a main switch 655 which is provided for connecting the circuit conductors 53 and 51 with a main electric supply source 65. The switch 65 may be manually operable or, if desired, may be arranged; as shown, with an operating coil 6T having one side connected to the main supply source 66 and its other side connected through a pair of control conductors 58 having connection with a remotely located push button 69 located adjacent the control program panel.

With further reference to Fig. 7, when a switch 49 is energized, in this case, the switch connected to the commonconductor 38, the conductor 3il is connected to the positive sideot the rectifier 48 so that current is fed through the associated symbol selector in flow paths containing the rectifiers or valves 41 and jumpers deatotpina receiving sockets= 3ll1 respectively connected to conductors 26 leading to the control coils 24 of the contacts 23, and thence back over common conductor 25 to the negativeside of therectifi'er' 48; Under such conditions, and as determined by the jumpers in the symbol selector, aparticular character will be displayed by the symbol former.

It will become apparent, however, that due to the fact that the pin sockets of the symbol selectors of each bank are connected to the same conductors 26, there might be occasions when feed-backs through jumpers of an assembled selector ofthe bank would permit energization of operating coils 24 of the symbol former, controlled by this bank, out of their proper sequence. It is for this reason that the valves 41 are utilized. Thus, the valves in the symbol selectors ofa connected group will operate to permit the passage of current in normal direction; whereas, the valves of one of the other groups will prevent passage of current in a reverse direction, which would be necessary to energize the coils 24 through a sneak or back circuit.

It will be apparent that the use of these valves. is particularly advantageous and results in greater economy of installation and operation than would otherwise be possible. These valves, however, being of the dry disc type of selenium or copper oxide rectifier, are inherently subject to occasional break-down, and will permit current to pass in an opposite direction. It has been found, however, that valves which have thus failed may be readily restored to normal condition by subjecting them to reversed current flow for a period of time.

The present control system guards against breakdown of the valves as well as for restoring them to operative condition, without the necessity of having to shut down or otherwise interf-ere with the operation of' the sign or its component parts. This is accomplished by the contacts of the switches 49. As previously explained, the contacts 5i operate to connect the selected group of symbol selectors to the positive side of rectifier 48. It will be noted, however, by reference to the contacts of the switches 49 which are associated with common conductors 30a and 30b, that the contacts 5| are in open position and the contacts 58 are in closed position. The conductors 30a and 3017 are thus connected to the negative side of rectifier flea, so that a reversed potential would be applied to any defective or-broken down valves which might be associated with the symbol selectors connected to the conductors 30a or 3%. The same is true of the valves of symbol selectors in any of the other groups of selectors which are not actively connected for energization ofthe symbol selectors in the normal manner:

I claim as my invention:

1. In changeable sign apparatus, the combination of: a symbol former having sections selectively energizable to form illuminated display characters; electrically actuated switches for respectively controlling said sections; a source of uni-directional electrical energy; control circuits for said switches extending from one side of said source of energy and including individual supply conductors; a plurality of symbol selectors, each having a first set of contacts connected respectively to said supply conductors and a second set of: contacts having a common connection; means forpre-selecting in each symbol selector interconnections between its sets of contacts; valves associated: with the pre-selected interconnections for limiting current flow to one direction therethrough; and switching means for successively connecting the common connections for the sy bol selectors to the other side of said source .of energy for normal current flow, and while each is so connected, applying reversed voltage across valves associated with other symbol selectors.

2. In changeable sign apparatus, the combination of a symbol former having a plurality of sections selectively illuminable to display characters; a source of electrical energy; means for controlling the illumination of said sections, each of said means having an operating coil connected on one side to said source of energy; individual supply conductors connected to the other sides of said coils; a plurality of symbol selectors connected with each of said conductors and having pre-selectable current flow paths therethrough from a common connection, valves in said paths for limiting current flow to one direction therethrough; switch means for successively connecting the common connections of the symbol selectors to said source of energy with the same polarity in each case; and means for applying a reversed polarity to the common connections of the symbol selector when unconnected by said switch.

3. In a changeable sign apparatus, the combination of a symbol former having a plurality of sections selectively illuminable to display characters; a source of electrical energy; means for controlling the illumination of said sections, each of said means having an operating coil connected on one side to said source of energy; individual supply conductors connected to the other sides of said coils; a plurality of symbol selectors connected with each of said conductors and having pre-selectable current flow paths therethrough from a common connection, valves in said paths for limiting current flow to one direction therethrough; electric polarity reversing switches connecting the common connections of the symbol selectors to said source of energy; and means for successively energizing said switches.

4. In a changeable sign apparatus, the combination of: a symbol former having a plurality of sections selectively illuminable to display characters; a source of electrical energy; means for controlling the illumination of said sections, each of said means having an operating coil connected on one side to said source of energy; individual supply conductors connected to the other sides of said coils; a plurality of symbol selectors connected to each of said conductors and having preselectablc current flow paths therethrough from a common connection with the other side of said source of energy; valves in said paths for limiting current flow to one direction therethrough; and switch means for successively reversing the polarity applied to said common connections by said source of energy.

5. In a changeable sign apparatus, the combination of: a symbol former having a plurality of sections selectively illuminable to display characters; a source of electrical energy; means for controlling the illumination of said sections, each of said means having an operating coil connected on one side to said source of energy; individual supply conductors connected to the other sides of said coils; a plurality of symbol selectors connected with each of said conductors and having pre-selectable current flow paths therethrough from a common connector; valves in said paths for limiting current flow to one direction therethrough; transfer switches having one position normally connecting the common connectors to one side of said source of' energy and another position connecting said common connectors to the other side of said source of energy; and means for actuating said switches from the one position to the other in timed sequence.

6. In a changeable sign apparatus, the combination of: a symbol former having a plurality of sections selectively illuminable to display characters; an energy source including a pair of rectifiers having a serie interconnection; means for controlling the illumination of said sections, each of said means having an operating coil connected on one side to the interconnection of said rectifiers; individual supply conductors connected to the other side of said coils; a plurality of symbol selectors connected with each of said conductors and having pre-selectable current flow paths therethrough from a common connector; valves in said paths for limiting current flow to one direction therethrough; transfer switches having one position normally connecting the common connectors to one polarity of said source of energy and another position connecting said common connectors to another polarity of said source of energy; and means for selectively actuating said switches.

'7. In combination with a changeable display sign having a plurality of devices selectively actuatable to control the form of the character displayed; a plurality of control conductors individually connected to said devices; a plurality of selectors, each connected with said control conductors and operable to pre-select current flow paths to one or more of said control conductors, from an energy source; valves in the flow paths of each selector permitting uni-directional current flow to said conductors; means for successively connecting the flow paths of each selector to the energy source for normal current flow; and means for subjecting valves of the selectors to reversed polarity during periods in which there is no normal current flow therethrough,

8. In an electrical device for connection with 7 a source of electrical energy: a symbol former having a plurality of actuatable sections; control means for selecting said sections, each of said means having an operating coil adapted to be connected to one side of said source of energy; individual supply conductors connected to the other side of said coils; a plurality of symbol selectors connected with each of said conductors and having pre-selectable current flow paths therethrough from a common connection; valves in said paths for limiting current flow to one direction therethrough; and means for supplying inverse polarity to said valves.

THOMAS ROSS WELCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 876,701 Drewell Jan. 14, 1908 1,346,493 Hammond et a1 July 13, 1920 1,763,113 Wensley June 10, 1930 1,795,536 Baker Mar. 10, 1931 2,356,094 Saslaw Aug. 15, 1944 FOREIGN PATENTS Number Country Date 499,900 Great Britain Jan. 31, 1931

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