US3778679A

US3778679A - Temperature sensitive electrical regulating device

Info

Publication number: US3778679A
Application number: US00313584A
Authority: US
Inventors: G Jonassen
Original assignee: TELECOMMUNICATION IND Inc
Current assignee: TELECOMMUNICATION IND Inc
Priority date: 1972-12-08
Filing date: 1972-12-08
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: GB1445622A; FR2335080A1; DE2344912A1; IT993877B; JPS555673B2; CH583981A5; SU522832A3; CA969599A; SE398575B; JPS4995165A; FR2335080B1

Abstract

A Temperature Sensitive Electrical Regulating Device comprising a multi-electrode gas tube arrestor having electrically coupled to each electrode an electrically conductive coupling element comprising an electrically insulative outer covering defining a cavity, and an electrically conductive member contained within said cavity such that upon the reaching of a particular temperature, the electrically conductive member changes its physical state causing a break in the electrical conductivity of said conductive member thereby lifting the three electrode gas tube arrestor off the line.

Description

United States Patent 91 J onassen TEMPERATURE SENSITIVE ELECTRICAL REGULATING DEVICE [75] Inventor: Gaylord D. Jonassen, Smithtown,

[73] Assignee: Telecommunication Industries, Inc.,

Copiague, N.Y.

[22] Filed: Dec. 8, 1972 [21] Appl. No.: 313,584

[52] 11.8. CI 317/40 A, 317/66, 317/71,

337/32 [51] Int. Cl. 1102b 5/04 [58] Field of Search 317/14 R, 14 N, 40 A,

[56] References Cited UNITED STATES PATENTS 3,386,063 5/1968 Mansfield 337/290 3,340,431 9/1967 Wanaselja 317/61 2,871,313 1/1959 Chabala et a1 317/40 A 1 Dec. 11, 1973 2,548,491 4/1951 Peek 317/40 A FOREIGN PATENTS OR APPLICATIONS 484,912 10/1929 Germany 317/62 Primary Examiner-J. D. Miller Assistant Examiner-Harry E. Moose, Jr. AttorneyAllen R. Morganstern [57] ABSTRACT 13 Claims, 6 Drawing Figures PATENIEDUEC 11 1915 3,778,679

slime 0F 2 M ,y/d. ELECTRICAL ENVIRONMENT SOURCE TO BE Y PROTECTED E ERG FIG.6

TEMPERATURE SENSITIVE ELECTRICAL REGULATING DEVICE BACKGROUND AND OBJECTS OF THE INVENTION The present invention relates generally to temperature-sensitive electrical regulating devices, and in particular, to temperature-sensitive electrical regulating devices that do not present a fire hazard under sustained overload conditions.

Prior to the present invention, when an overload condition occurred in a particular electrical environment, as for example when a power line would fall onto a telephone line as the result of a storm, there would be induced in the telephone line currents far in excess of what would normally be carried by the line. If this were to occur, not only would any electrical device coupled to said line be subject to destruction, but in addition, a fire hazard would be created with regard to any structure to which the telephone line is connected as a direct result of the overload carried by the telephone lines.

Although a variety of tube-type protective devices are employed to protect against an overload condition as set forth above, under such circumstances, the protective devices currently available on the market can become a fire hazard in and of themselves due to the excessive heat they generate as they shunt the overload.

It is therefore an object of this invention to create a new and improved electrical regulating device that overcomes the disadvantages of the prior art devices.

It is another object of this invention to create a new and improved electrical regulating device that does not become a tire hazard under an overload condition.

It is another object of this invention to provide a new and improved electrical regulating device that is compact in design, rugged in construction, and economical to manufacture.

It is another object of this invention to provide a new and improved electrical regulating device that is responsive to thermal stimulus.

; It is another object of this invention to provide a new and improved electrical regulating device whose thermal sensitivity is variable.

It is another object of this invention to provide a new and improved electrical regulating device that is operative for both an over voltage condition as well as for an excessive current condition.

The objects and advantages of the invention are set forth in part herein and in part will be obvious herefrom, or may be learned by practice of the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations, and improvements herein shown and described.

SUMMARY OF THE INVENTION Briefly described, the present invention is directed to a novel and improved temperature-sensitive electrical regulating device that does not become a fire hazard under overload conditions. As herein preferable embodied, a three electrode gas discharge tube is encapsulated within an electrically insulative shell having thermal insulative potting material packed between said electrically insulative shell and said gas discharge tube.

Coupled to each electrode of said gas discharge tube is a coupling element comprising an electrically insulative outer covering that encapsulates an inner core of electrically conductive material. The outer covering is designed to provide structural integrity as well as insulative and aesthetic properties. The inner core of electrically conductive material comprises a fusable electrically conductive lining of a hollow configuration which is in turn electrically coupled to a solid core of electrically conductive material. The above described coupling element has its fusable electrically conductive lining of hollow configuration end electrically coupled to each electrode of said gas tube while the other end of said coupling element is free for coupling into an electrical network. In keeping with the invention, when said temperature sensitive electrical regulating device is presented with an overload condition, the gaseous environment of said gas discharge tube ionizes providing a conductive path for shunting the path of excessive current resulting from an overload condition. As the condition continues, the termperature of the regulating device increases and under a sustained overload condition would become a fire hazard but for the fact that the fusable electrically conductive link of hollow configuration encapsulated within said electrically insulative outer covering is also heated and upon reaching its melting point which is calculated to be at a level below which the device becomes a fire hazard, the electrically conductive link melts thereby flowing into the hollow area heretofore defined by the electrically conductive link thus causing a break in the electrically conductive path defined by said electrically conductive link.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention, but are not restrictive thereof.

The accompanying drawings referred to herein and constituting a part hereof, are illustrative of the invention but not restrictive thereof, and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a temperaturesensitive electrical regulating device constructed in accordance with the invention.

FIG. 2 is a cut-away view along line 2-2 of the temperature-sensitive electrical regulating device illustrated in FIG. 1.

FIG. 3 is a partial cut-away view of the temperaturesensitive electrical regulating device illustrated in FIG. 1.

FIG. 4 is a cross-sectional view of another embodiment of a temperature-sensitive electrical regulating device constructed in accordance with the invention.

FIG. 5 is an enlarged cut-away view of another embodiment of a temperature-sensitive electrical regulating device constructed in accordance with the invention wherein the electrically conductive coupling element utilized comprises an inner core of closely packed granules of electrically conductive material.

FIG. 6 is a schematic block diagram illustrating the temperature sensitive electrical regulating device coupled within an electrical environment in accordance with the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now more particularly to the embodiments of the invention shown in the accompanying drawings, there is illustrated in FIG. I a temperature-sensitive electrical regulating device indicated generally by reference numeral 10.

In accordance with the invention, temperaturesensitive electrical regulating device comprises a housing 11, into which is encapsulated a gas discharge tube arrestor 12. In keeping with the invention, housing 11 can take almost any form or shape and can be made from any electrically insulative material. As depicted in FIGS. 1-3, one representative embodiment of the invention has housing 11 take on a rectangular shape having a somewhat square cross-section.

In accordance with the illustrative embodiment set forth in the drawings, gas discharge tube arrestor 12 is of a three electrode type, however, nothing herein should be construed to restrict the applicability of this invention to only three electrode gas discharge tube arrestors. On the contrary, this invention is applicable to any gas discharge tube arrestor, be it a one electrode device or be it a multi-electrode device.

As illustrated in FIGS. 2 and 3, gas discharge tube arrestor 12 is positioned within housing 11 and physically separated from the walls of housing 11 by thermal insulating potting material 13. In keeping with the invention, thermal insulating potting material 13 provides the means whereby thermal energy, generated by gas discharge tube 12, when said tube conducts under an overload condition, is reflected back within the confines of housing 11, and in particular, reflected back to the structure of gas discharge tube 12 and not permitted to dissipate to the surrounding environment.

In accordance with the invention, electrically conductive coupling element 14, as illustrated in FIG. 3, comprises an electrically insulative outer wall member 15 that is cylindrical in shape and defines an inner cavity running the entire length of tis structure. As further depicted in FIG. 3, electrically conductive coupling element 14 has, contained within the cavity defined by electrically insulative outer wall member 15, an electrically conductive lining Id of hollow configuration that occupies a portion of said defined cavity wherein one end of said electrically conductive lining 16 is electrically coupled to an electrode of said gas discharge tube 12 via solder connection 17 and the other end of said electrically conductive lining I6 is electrically coupled via solder connection 18 to a solid core of electrically conductive wire 19 having its own electrically insulative covering, said solid core of electrically conductive wire 19 occupying the remainder of the defined cavity of electrically conductive coupling element 14. Electrically conductive wire I9 has its free end, namely, that end which is not electrically coupled to fusable electrically conductive lining 16, coupled to horseshoe coupling member 21 so as to provide a means for fascilitating the coupling of temperature sensitive electrical regulating device 10 into an electrical environment.

It should be pointed out that although electrically conductive coupling element 14, as illustrated in FIG. 3, and as hereinafter discussed, has a portion of it consist of an electrically conductive wire while the remaining portion of said electrically conductive coupling element consists of an electrically conductive lining having a hollow configuration, nothing herein should be interpreted so as to restrict the invention to only such an embodiment. On the contrary, it should be understood that the present invention has wide applicability to a variety of embodiments other than the embodiment specifically illustrated in FIG. 3.

In contrast to the prior art devices currently on the market which attempt to dissipate to the surrounding environment the thermal energy generated by a conducting gas discharge tube, and thus in that manner attempt to avoid becoming a fire hazard, the construction and theory of operation of the persent invention seeks, via thermal insulating potting material 13, to retain within the device the thermal energy generated by gas discharge tubel2, resulting in the concentration of thermal energy as opposed to its dissipation. As will become evident, this conceptual operative difference from the prior art devices currently available on the market permits the present invention to function as an electrical regulating device that can sense both voltage and current overload conditions and respond thereto without becoming a fire hazard under a sustained overload condition.

Referring back to FIGS. I, 2, and 3, there is illustrated electrically conductive coupling elements l4, l4'.and 14''. As per the embodiment depicted therein, a three electrode gas discharge tube arrestor has electrically coupled to each of its electrodes, an electrically conductive coupling element, be it 14, I4 and 14''. It should, however, be kept in mind that although an illustrative embodiment of the present invention depicted in the drawings illustrates a three electrode gas discharge tube arrestor with identically designed electrically

conductive coupling elements

14, 14' and 14" re spectively coupled to each of said electrodes, nothing herein should be construed as to limit the invention to a three electrode device, or a device with each electrode having coupled thereto electrically conductive coupling element of identical design. On the contrary, the present invention is applicable to a device compromising a gas discharge tube arrestor having any number of electrodes as well as a device that has all or in the alternative any combination thereof of said electrodes electrically coupled to an electrically conductive coupling element of a design as setforth herein.

In particular, electrically conductive coupling element I4 can have electrically conductive lining 16 of hollow configuration run the entire length of electrically conductive coupling element 14 and totally eliminate the use of electrically conductive wire 19; or, their combine utilization as illustrated in FIG. 3, can be, with regard to their respective lengths, as compared to the overall length of electrically conductive coupling ele ment M, of any desire ratio. Additionally, it is wihtin the scope of this invention to utilize as electrically conductive lining 16, a conductive lining that is not restrictive merely to the embodiment illustrated in FIG. 3. Although FIG. 3 illustrates a fusable electrically conductive lining 16 having a hollow configuration, it is within the scope of this invention to encompass all variations of design that effectuate a break in the electrical conductivity of said electrically conductive lining 16 upon having said lining reach a predetermined temperature, be said design take the form of a composition whose re sistance versus temperature plot effectuates the equivalent of an open circuit once said composition reaches a particular temperature level, or as illustrated in FIG. 5, having said lining take the form of closely packed granules 22 of electrically conductive material which, upon reaching a predetermined temperature level, will fuse into one solid mass which occupies only a portion of the volume heretofore occupied by the granules of electrically conductive material, thereby causing a break in the electrical conductivity of said granule structure, or as illustrated in FIG. 3, having said lining take the form of an electically conductive hollow lining which, upon reaching a predetermined temperature level, will change into a liquid thereby flowing into the cavity defined by the heretofore rigid hollow structure of said electrically conductive lining thus causing a break in the electrical conductivity of said hollow lining structure, or as illustrated in FIG. 4, having solder connection 23, that electrically couples electrically conductive coupling element 14 to gas discharge tube arrestor 12, positioned within a cavity formed within thermal insulating potting material 13 such that upon reaching a predetermined temperature level, solder connection 23 will liquify thereby flowing into the cavity formed within said potting material thereby causing a break in the electrical conductivity between the electrode of said gas discharge tube arrestor and said electrically conductive coupling element.

In addition to the various forms which electrically conductive; coupling element 14 may take, it is also within the scope and intent of this invention to, by proper design, to selectively set the temperature at which electrically conductive coupling element 14 will no longer electrically conduct. Such regulative capability can take the form of selectively combining the elements of composition that comprise electrically conductive lining 16 or its alternate equivalents such that a composition of matter is fabricated that has the predetermined desired melting point.

With the above in mind, attention is now drawn to the operation of one embodiment of temperaturesensitive electrical regulating device as illustrated in FIGS. l-3 and 5. In operation, electrically

conductive coupling elements

14 and 14 are electrically coupled across a source of electrical energy and between said source and the electrical environment that is to be protected (FIG. 5). In addition, electrically conductive coupling element 14" is electrically coupled to ground. In accordance with the invention, when an overload condition occurs, the gaseous content of gas-tube arrestor l2 ionizes thereby providing a direct conductive path to ground via electrically conductive coupling element 14" thus shunting to ground any overload.

If the overload condition prevails, gas-discharge tube arrestor 12 of temperature-sensitive electrical regulating device 10 will begin to risev in temperature. In accordance with the invention, this rise in temperature is concentrated within the device itself by thermal insulating potting material 13 and not permitted to dissipate to the surrounding environment as is the case with the prior art devices which thereby create a fire hazard under sustained overload conditions. On the contrary, the present invention concentrates, to within the device, the thermal energy generated by having gasdischarge tube arrestor I2 placed into an ionized state, thereby raising the temperature of electrically conductive coupling elements l4, l4, and 14". upon having the electrically conductive lining 16 as illustrated in FIG. 3 of'electrically conductive coupling elements l4, l4 and I4" reach their respective melting points, said conductive linings will melt and will flow into the hollow cavity heretofore formed by the hollow configuration of an unmelted lining 16 thus causing a break in the electrical conductivity of coupling elements M, 14 and 14" resulting in having temperature-sensitive electrical regulating device 10 lifted off of the line without becoming a fire hazard. As previously discussed, electrically conductive lining 16 is fashioned such that its melting point is below that temperature which would result in having temperature-sensitive electrical regulating device it) become a fire hazard. in keeping with the invention,

coupling elements

14, 14' and 14" may either be identical in design and fabrication and thus melt at the same temperature, or alternatively, be of different designs and fabrication and thus melt at separate and distinct temperature levels thereby providing a particular sequence of operation or alternatively, it is within the scope of this invention to utilize in place of any one or more of said coupling elements 14, i4 and 14'', a conductive connector or connectors as the case may be, which do not create an open circuit condition at a particular temperature level thereby keeping the respective electrode of said gas discharge tube-arrestor electrically coupled to the electrical environment regardless of the temperature level of the device.

As is obvious from the above, the temperaturesensitive electrical regulating device of the present invention is a non-resetable device and thus once the device has been triggered, it must be replaced before overload protection is again achieved. Additionally, it is also obvious that once the device has been triggered and it has been lifted off of the line so as to avoid becoming a fire hazard, that the electrical environment across which said device was coupled is no longer protected. As a result, it is therefor within the scope of this invention to utilize said temperature-sensitive regulating device in combination with other back up overload protection means.

It should also be noted that in addition to acting as a protective device for detecting and protecting from an overload voltage condition, it is additionally within the scope and intent of this invention to have said temperature-sensitive electrical regulating device 10 respond to overload current conditions. The above is accomplished upon the realization that the low of excessive current through electrically conductive lining 16 will, due to the resistance of lining l6, generate heat, which thereby raises the temperature of lining I6 and upon reaching a predetermined level which is relative to and indicative of an excessive current level, said lining will melt, and as previously described above with regard to an excessive voltage condition, said lining will flow into a cavity heretofore formed by its configuration, resulting in a break in the electrical conductivity of said lining, thereby having temperature-sensitive electrical regulating device It) lifted off of the line due to the detection of an excessive current condition.

The preceding description and accompanying drawings relate primarily to the use of the invention as a temperature sensitive electrical regulating device for utilization within an electrical environment for protection against overload conditions. Although specific reference has been made to the utilization of the present invention within an electrical environment for protection in association with telephone equipment, it should be understood that the invention as herein described is not so limited, but is equally applicable for use as a means for protecting from damage due to an unexpected overload condition, any item of electrical equipment, be it a telephone, a T.V., a radio, a transformer or any other item of electrical manufacture. Thus, the invention in its broader aspects is not limited to the specific embodiment herein shown and described, but departures may be made therefrom within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

I CLAIM:

l. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions, said device compromising:

a. An electrically insulative walled enclosure defining a cavity;

b. A gas discharge tube arrestor having at least one electrode, said gas discharge tube arrestor being positioned within the hollow cavity of said walled enclosure;

c. Thermal insulative material encapsulating said gas discharge tube arrestor so as to provide a thermal insulative barrier between the walls of said electrically insulative walled enclosure and said gas discharge tube arrestor;

. Electrically conductive coupling elements for electrically coupling each electrode of said gas discharge tube arrestor to said electrical environment, said electrically conductive coupling elements compromising:

i. An electrically insulative outer wall member defining a cavity;

ii. An electrically conductive inner member contained within said cavity defined by said electrically insulative outer wall member, said electrically conductive inner member having its electrical conductivity interrupted upon having any portion of said electrically conductive inner member reach a predetermined temperature level; and

iii. Means for electrically coupling one end of an electrically conductive coupling elementto each respective electrode of said gas discharge tube arrestor.

2. A temperature sensitive electrical regulating device as described in claim 1 wherein said gas discharge tube arrestor is of a multi-electrode design.

3. A temperature sensitive electrical regulating device as described in claim 2 wherein said gas discharge tube arrestor is of a three electrode design.

4. A temperature sensitive electrical regulating device as described in claim 1 wherein said electrically conductive inner member of said electrically conductive coupling element is an electrically conductive hollow member which is coincident with said electrically insulative outer wall member.

5. A temperature sensitive electrical regulating device as described in claim 1 wherein said electrically conductive inner member of said electrically conductive coupling comprises granuals of closely packed electrically conductive material.

6. A temperature sensitive electrical regulating device as described in claim 1, wherein said thermal insulative material encapsulating said gas discharge tube arrestor defines a cavity wherever an electrically conductive coupling element is electrically coupled to an electrode of said gas discharge tube arrestor.

7. A temperature sensitive electrical regulating de-' vice for protecting an electrical environment against overload conditions as describe in claim ll wherein said device is responsive to both voltage and current overload conditions.

8. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions, said device comprising:

a. Gas discharge tube arrestor having at least one electrode, and

b. An electrically conductive coupling element for electrically coupling each electrode of said gas discharge tube arrestor to said electrical environment, said electrically conductive coupling element comprising:

i. An electrically insulative outer wall member defining a cavity;

ii. An electrically conductive inner member contained within said cavity defined by said electrically insulative outer wall member, said electrically conductive inner member comprising an electrically conductive hollow member coincident with a portion of said electrically insulative outer wall member and an electrically conductive core member electrically coupled to said electrically conductive hollow member and coincident with the remainder of said electrically insulative outer wall member;

iii. means for coupling the electrically conductive hollow member portion of said electrically conductive coupling element to each electrode of said gas discharge tube arrestor, and

iv. means for coupling the electrically conductive core member of siad electrically conductive coupling element to said electrical environment.

9. A temperature sensitive electrical regulating device as described in claim 8, additionally comprising an electrically insulative walled member defining a cavity wherein said gas discharge tube arrestor is placed within said cavity having thermal insulative material positioned between the walls of said electrically insulative walled member and said gas discharge tube arrestor.

10. A temperature sensitive electrical regulating device as described in claim 8 wherein said gas discharge tube arrestor is of a multi-electrode design.

11. A temperature sensitive electrical regulating device as described in claim 8 wherein said gas discharge tube arrestor is of a three electrode design.

12. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions as described in claim 8, wherein said device is responsive to both voltage and current overload conditions.

13. A temperature sensitive electrical regulating device as describe in claim wherein said thermal insulative material encapsulating said gas discharge tube arrestor defines a cavity wherever an electrically conduc tive coupling element is electrically coupled to an electrode of said gas discharge tube arrestor.

Claims

1. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions, said device compromising: a. An electrically insulative walled enclosure defining a cavity; b. A gas discharge tube arrestor having at least one electrode, said gas discharge tube arrestor being positioned within the hollow cavity of said walled enclosure; c. Thermal insulative material encapsulating said gas discharge tube arrestor so as to provide a thermal insulative barrier between the walls of said electrically insulative walled enclosure and said gas discharge tube arrestor; d. Electrically conductive coupling elements for electrically coupling each electrode of said gas discharge tube arrestor to said electrical environment, said electrically conductive coupling elements compromising: i. An electrically insulative outer wall member defining a cavity; ii. An electrically conductive inner member contained within said cavity defined by said electrically insulative outer wall member, said electrically conductive inner member having its electrical conductivity interrupted upon having any portion of said electrically conductive inner member reach a predetermined temperature level; and iii. Means for electrically coupling one end of an electrically conductive coupling element to each respective electrode of said gas discharge tube arrestor.

7. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions as describe in claim 1 wherein said device is responsive to both voltage and current overload conditions.

8. A temperature sensitive electrical regulating device for protecting an electrical environment against overload conditions, said device comprising: a. Gas discharge tube arrestor having at least one electrode, and b. An electrically conductive coupling element for electrically coupling each electrode of said gas discharge tube arrestor to said electrical environment, said electrically conductive coupling element comprising: i. An electrically insulative outer wall member defining a cavity; ii. An electrically conductive inner member contained within said cavity defined by said electrically insulative outer wall member, said electrically conductive inner member comprising an electrically conductive hollow member coincident with a portion of said electrically insulative outer wall member and an electrically conductive core member electrically coupled to said electrically conductive hollow member and coincident with the remainder of said electrically insulative outer wall member; iii. means for coupling the electrically conductive hollow member portion of said electrically conductive coupling element to each electrode of said gas discharge tube arrestor, and iv. means for coupling the electrically conductive core member of siad electrically conductive coupling element to said electrical environment.

13. A temperature sensitive electrical regulating device as describe in claim 9, wherein said thermal insulative material encapsulating said gas discharge tube arrestor defines a cavity wherever an electrically conductive coupling element is electrically coupled to an electrode of said gas discharge tube arrestor.