US1995055A - Method and means for protecting neon signs and circuits - Google Patents

Description

March 19, 1935. J. DE PUDDICOMBE METHOD AND MEANS FOR PROTECTING NEON SIGNS AND CIKCUITS Filed Aug. 51, 1932.

. INVENTIIOR- I c? d'e Paddz'co'mbe MW-6 BY r W! ATTORNEY- Patented Mar. 19, 1935 METHOD AND MEANS FOR PROTECTING NEON SIGNS AND CIRCUITS Jack De Puddicombe, New York, Y. Application August '31, 1932, Serial No. 631,107

11 Claims, (01. 176124) This invention relates to collectively and individually disposed electrical conductors in which a source of supply as of high voltage is operative, and has particular reference tomultiple and series couplings in which illuminated neon or gaseous display tubes are arranged and to provide combined protection, subsequent to partial damage of the system.

In the neon display sign or illuminated sign field, in which a single source of supply, in the form of a high tension transformer or induction coil, is effective to transmit stepped up A. C. current to the separate letters or members of the multiple series or series multiple group, each of these includes cooperating terminals or electrodes, in the known manner,and one of the objects of this invention is the provision of a method of preventing the entire system from becoming inoperative, in the event of a sudden breakdown or leakage in one of the letter members, as has heretofore been the case, thereby to keep the normal letter elements of a group illuminated.

Another object of the invention, connected with the foregoing, is the provision of means which, when shunted across the electrodes of a single member, as aforesaid, may be effective to so control the current as to preclude the possibility of a breakdown in the remainder of the members of the system. Each member is provided with such shunt means.

Another object of the present invention in the event of a breakdown of one of the letter members of a group, is to prevent an overload on the transformer, and to maintain the load thereon at a constant, even though one or more letter elements of a sign group cease to function.

Each gaseous tube or letter oifers a certain resistance between its electrodes, and a feature of the invention is a control or safety device which, when disposed in the shunt wiring, is of such conductive properties as to remain dormant or inac-' tive while the tube is illuminated, but which, when the tube becomes damaged or inactive from any cause, as is frequently the case in practice,

may be effective to carry the current past the said'electrodes to a cooperating or second tube, so that the latter as well as the other units in the assembly may be entirely free from the effect of the damaged member and the load on the transformer kept constant, without danger of shorting of the transformer and the consequent fire hazard which results therefrom.

. Since such former breaks in the circuit, primarily involving a single unit of the sign, have usually, if not invariably, been accompanied by a short circuit in the transformer, due to com-' plete out put of the entire neon sign group, a'further object of the invention is to prevent the overload of the short circuiting action, with a view to prolonging the effective life of the transformer. 5

As a break in single members of the sign system has involved the whole of the combined auxiliary sign members, as already indicated, inconvenience has been experienced in detecting a single damaged tube, when all of the letter members are dead and a still further object of this invention is to render each of the aforesaid neon sign members visible as they remain operative, so that the associated damaged and unlighted neon letter member may be easily visually detected for removal or replacement.

Further, if the shunt tube housing is made of lass, activity of the shunt terminals, upon breakdown of a letter may be seen by reason of the arcing of the shorting current across the gap of the shunt device.

Considerable flickering has occurred in systems of this type, as heretofore constructed, subsequent to injury or damage to one of its units, and yet another object of this invention is to so conduct the current past the defective member as to cause entire absence of flickering, with uniform luminosity of the tubes unaffected by the breakdown of the defective member.

With the above indicated objects and advantages in view, and others which will hereinafter appear, the invention resides inthe novel construction, combination; arrangement and relative location of parts, which are hereinafter clearly described, and fully illustrated in the accompanying drawing, in which:

Fig. 1 is a diagrammatic view of an electric circuit in which a sign, consisting of a number of illuminating neon tube letters in multiple, each with a separate control or shunt element, is incorporated.

Fig. 2 is a like'view, except that one of the letters is represented in damaged or inactive condition, with its associated control or shunt device functioning.

Fig. 3 is an elevational view of a control device, per se.

Fig. 4 is an end view of the device shown in Fig. 3, and

Fig. 5 shows a slight modification of structure, in which the letters are connected in series multiple.

Similar characters of reference are applied to corresponding parts throughout the various views.

The particular embodiment of the novel cir- 8B cuit control means or auxiliary tube 1 here selected for illustration includes a shell 2, which may be of any insulating material, such as glass, porcelain or fibre. Air-tightly mounted on one end of this shell, as seen in section in Fig. 3, is a cap which includes a member 3, and engaging the said member is a disk 4, which has an integral conductive perforated ear 4'.

The structure of the other end of the tube is identical with that of the first, so that the description is equally applicable to both. Disposed within the housing thus formed is a pair of conductors, each numbered 5. The outer ends of these conductors are riveted to their respective caps, as at 6, while their inner ends or electrodes, hereinafter further referred to are spaced apart to form a gap '7.

As shown in Fig. 1, the transformer A includes the known primary coil which is supplied with alternating current from any source; and cooperating with the first coil is a secondary or high tension winding, so that the voltage is increased from 110 in the primary coil to about 15,000 volts in the secondary coil and tube circuit.

Extending from the high tension coil is wiring 8, a continuation 9 of which is connected with the opposite end of the coil. Between the wires 8 and 9 are terminals, with which cooperating terminals or electrodes 11, 12 of a gas tube or letter 10 cooperate to normally close the circuit thereat. The tube in the present instance is formed as the letter E, and two other tubes A and T are also designated 10, so the letters form a word, as an example.

Disposed in parallel with the first letter is the second letter, there being a wiring portion 13 which extends from the wire 8 to the electrode 11 of said second letter; and then from the other electrode 12 of the letter another wiring portion 14 connects with the wire 9. The third letter T is also connected in parallel, there being a wiring portion 15, which connects at 11, and another portion 16 which extends from the electrode 12 to the wire 9.

.The gaseous circuit through a tube made luminous by the passage of a high tension electrical current, supplied usually by an alternating current transformer, operating on 110 volts A. C. current supply, offers a certain resistance to the output of the transformer. When the circuit through the gaseous tube circuit is broken, through fracture of the transparent glass wall thereof, or leakage through the terminal electrade on either end of the tube, which results in a change of internal pressure in the tube and a consequent loss of conductivity, the gaseous tube will cease to be luminous. If there is no relief circuit then offered for the output of the transformer, it will steadily increase in temperature, until the heavy tar or similar plastic insulation used generates excessive internal pressure, and finally explodes, with dangerous destructive actionto life and property.

The shunt circuit which I provide for each individual gaseous luminous tubing is designed to offer a moderately higher resistance to the output of the transformer, so that when the internal circuit of the related tubing is properly functioning the shunt circuit will be inactive, and to instantly function when the internal circuit of the tubing is broken. There is no time lag between the period when the tubing circuit ceases to be luminous or active, or is broken, and the time when the shunt circuit, through the moderately higher resistance offered by the air are gap, becomes active. The substitution of the shunt circuit for the normal luminous circuit through the gaseous tubing is instantaneous. The distance of the gap between the confronting ends of the electrodes of the shunt by-pass determines the amount of the higher resistance offered by the shunt by-pass to the flow of the high tension current of the transformer.

The flow of the high tension electrical current across the air arc gap, within the transparent glass tube of the shunt by-pass device, produces a luminous effect, by means of which the active shunt may be readily and'positively detected, in a sign assembly involving many individual letter forms.

The arrangement of terminals in the wiring for each sign or letter form, with which the terminals of the associated sign or letter form tubing cooperate, affords means for 'removably mounting the individual letter or sign form, in a group assembly. But this means, in combination with the safety shunt by-pass, combines to provide a circuit for a sign assembly wherein any damaged or non-luminous sign tubing part or letter may be withdrawn, without interrupting or breaking the circuit of the luminous sign tubing parts, and a fresh or replacement part or letter placed in position. Due to the fact that the shunt which became active when the damaged tubing became inactive will also have a higher circuit resistance than the circuit of the replacement gaseous tubing, the high tension electrical current will naturally take the path of least resistance, when the replacement tubing is placed in proper circuit relation to the wire terminals of the removed tubing, the high tension electrical current will instantly flow through the substitute tubing, avoiding the shunt by-pass associated therewith. This will result, of course, in the replacement tubing becoming immediately active or luminous.

This circuit arrangement and relationship of the parts of the sign assembly is such, that a very quick replacement of a damaged tubing may be made, and full luminosity develops with this replacement.

During this operation the air within the chamber of the tube, at the gap '7, becomes ionized, which lowers the electrical resistance, and provides a current path between the electrodes of the auxiliary tube.

Each neon letter tube is provided with an auxiliary shunt tube 1. Shunt wiring portions 19, 20 connect the auxiliary shunt tube across the electrodes of second letter 10, this being between the wires 13 and 14; and shunt portion 21 and 22, with the auxiliary shunt tube, connect the wires 15, 16 across the electrodes 11, 12 of the third letter T.

In Fig. 2 where the structure is like that already described, the neon letter is represented as broken down or inactive, and in this case the gap '7 is shown, diagrammatically as being in the act of passing the current over said gap.

In the series multiple circuit, Fig. 5, wires 13' and 14' connect with the electrodes of the second letter 10, and wires 15' and 16, on opposite sides of the electrodes of the third letter T, are effective to connect with the wiring 9. In this case the shunt wires for the auxiliary shunt tube of the first letter 10 are the same as those of Fig. 1; wires 19' and 20' cooperate with the auxiliary shunt tube of the center letter, and the wires for the device 1 which is in shunt across the electrodes of the tube T are represented at 21' and 22'. Thus in this circuit all of the letters are provided with shunt tubes across their terminals in series multiple.

Considerable particularities of description, as to materials, detail of parts, capacities and utilities are hereinbefore stated, but it will be understood that these statements, made with particular reference to the elements now preferred, of the many possible embodiments of the invention which are contemplated are not in any way to be taken as limitative of the invention. Inasmuch as many changes could be made without departing from the scope thereof, it is intended that all matter contained in the foregoing descriptionor shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. While I have shown specific embodiments of the invention, it is understood many changes may be made within the scope of the claims, which are to be interpreted as broadly as is consistent with the prior art. It is particularly noted that the expression neon tubes" and neon gas discharge tubes is used generically to cover gas discharge tubes having therein neon or helium or mixtures of these and other gases, or vapors, and other similar tubes.

What I claim is:

1. In combination, a high tension circuit including, in series therein, a plurality of neon tubes and a substantially constant-voltage transformer secondary individual to said circuit; and an arc gap device shunted around each of said tubes; said are gap comprising a pair of spaced electrodes electrically connected respectively to opposite terminals of the associated tube,and forming a non-leaking arc gap.

2. An illuminating system comprising a high tension circuit including, in series therein, a plurality of luminous neon gas discharge tubes and a substantially constant-voltage transformersecondary individual to said circuit and having a capacity between 3,500 and 15,000 or more volts; an arc gap device shunted around each of said tubes; said are gap comprising a dielectric chamber filled with air substantially at atmospheric pressure; and a pair of spaced electrodes mounted in said chamber, and electrically connected respectively to opposite terminals of the associated tube, and forming a non-leaking arc gap.

3. A system as in claim 2 in which said chamber is a glass chamber.

4. A system as in claim 2 in which said chamber is a porcelain chamber.

. 5. A system as in claim 2 in which said chamber is a fiber chamber.

6. A system as in claim 2 in which said electrodes have substantially coaxially alined circular opposed inner ends having sharp circumferential edges which cause the arc during by-' passing to pass only at a small point of each edge and to reset the arc from such point to another small part only of the edge when said point gets hot, thereby to prevent excessive heating of the electrodes, during by-passin'g and to prevent increase of resistance of the arc during by-passing.

'7. A system as in claim 2, said gap being of such length that thebreak-down resistance of the gap is normally slightly higher than the normal operating resistance of the associated tube; the heating of the air in the chamber, during by-passing when a tube breaks down, decreasing the gap resistance to approximately equal the normal resistance of such tube, thereby to maintain the transformer load approximately con.- stant and to maintain the operative tubes in an operative .circuit; the resistance of the gap when of said length being at all times great enough to snuff out the are when a removed associated tube in normal condition is replaced in the circuit.

8. A system as in claim 2, in which the breakdown resistance of said gap is normally slightly higher than the normal operating resistance of the associated tube, the heating of the air in the chamber when a tube breaks down and the arc persists decreasing of the gap resistance to approximate normal resistance of the tube, thereby to maintain the transformer load approximately constant. and the operative tubes in operative circuit; said control devices being at all times capable of absorbing and dissipating the entire load of the transformer and any increase in power as'the voltage increases, thereby preventing excessive potential rise and injury by the transformer to itself and preventing excessive voltage drop around the device.

9. A system as in claim 1 in which the breakdown resistance of said control device isnor-" mally slightly higher than the normal operating resistance of the associated tube, and decreases during by-passing to approximate the normal resistance of such tube, thereby to maintain the transformer load approximately constant and the operative tubes in operative circuit; the resistance of the device being at all times great enough to snufi out the are at the jump gap when a removed associated tube in normal condition is replaced in the circuit; said device being at all times capable of absorbing and dissipating the entire load of the transformer and any increase in power as the voltage increases,

thereby preventing injury by the transformer to itself.

10. In combination, a high tension circuit having opposed terminals, a plurality of neon tubes connected in multiple between said terminals and an arc gap device shunted around each of said tubes; said arc gap device comprising a pair of spaced electrodes electrically connected respectively to opposite terminals of its associatedtube and forming a nonleaking arc gap.

11. In combination, a high tension circuit including, in series therein, a plurality of neon tubes; and an arc gap device shunted around each of said tubes; said arc gap device comprising a pair of spaced electrodes electrically connected respectively to opposite terminals of the associated tube and forming a non-leaking arc JACK PUDDICOMBE.

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