US3578896A

US3578896A - Electrical connector with fusible plug means and heating material

Info

Publication number: US3578896A
Application number: US865346A
Authority: US
Inventors: Leslie S Lynch
Original assignee: Thomas and Betts Corp
Current assignee: RELIABLE POWER PRODUCTS Inc A CORP OF DE(FKA) MACLEAN-FOGG ACQUISITION Co; ABB Installation Products Inc
Priority date: 1969-10-10
Filing date: 1969-10-10
Publication date: 1971-05-18
Anticipated expiration: 1988-05-18

Abstract

A connector for coupling at least one electrical conductor to a further conductor, or other element, comprising an outer insulating sleeve containing within a longitudinal passage therethrough a fusible plug of material for joining such elements. A heating member may be imbedded within the insulating sleeve about the fusible plug or external to the insulating sleeve and will upon operation cause fusion of the fusible plug. Ports may be provided from the outer surface of the sleeve to the heating member for external operation thereof and for the insertion of temperature sensing probe within the fusible plug. Seals for the various ports are provided to insure the integrity of the outer insulating sleeve.

Description

United States Patent Leslie S. Lynch Martinsville, NJ.

Oct. 10, 1969 May 18, 1971 Thomas & Betts Corporation Elizabeth, NJ.

[72] Inventor [21 Appl. No. [22] Filed [45 Patented [73] Assignee [54] ELECTRICAL CONNECTOR WITH FUSIBLE PLUG MEANS AND HEATING MATERIAL 10 Claims, 6 Drawing Figs.

[52] U.S. Cl l74/84R, 29/628, 156/49, 174/49, 219/95, 219/85, 228/56 [51] Int. Cl. H02g 15/08 [50] Field of Search 174/84, 88,

3,308,532 3/1967 Long et al 228/56X 3,360,631 12/1967 Hess 219/85 3,417,195 12/1968 Shlesinger, Jr. 174/84 Primary Examiner-Darrell L. Clay Att0rneyDavid Teschner ABSTRACT: A connector for coupling at least one electrical conductor to a further conductor, or other element, comprising an outer insulating sleeve containing within a longitudinal passage therethrough a fusible plug of material for joining such elements. A heating member may be imbedded within the insulating sleeve about the fusible plug or external to the insulating sleeve and will upon operation cause fusion of the fusible plug. Ports may be provided from the outer surface of the sleeve to the heating member for external operation thereof and for the insertion of temperature sensing probe within the fusible plug. Seals for the various ports are provided to insure the integrity of the outer insulating sleeve.

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AT TORNE Y ELECTRICAL CONNECTOR WITH FUSIBLE PLUG MEANS AND HEATING MATERIAL BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to the field of coupling two or more conductors to one another or to such other elements such as dead ends, terminal pads or similar elements. Such connectors may be used for overhead, or underground, cable installations or any other installation. where it is desired to have a preinsulated splice which can be easily coupled to the conductors or other elements to be joined.

2. Description of the Prior Art In the prior art, connectors for joining conductors or connectors for joining conductors to devices such as dead ends, terminal pads or the like were uninsulated and required, after their initial installation to the conductors, or dead ends, by means of compression devices the laborious task of building up a tape layer in order to insure afully insulated splice. It was not possible to preinsulate the splice by providing a complete unit which could be attached in the field at the point of actual use, such as within a manhole in which a cable was to be placed. Heavy equipment was necessary to operate the compression sleeves. Test equipment was necessary to determine the value of the taped splice when completed. Its true value could not be told for some period of time until the splice was subjected to moisture, dirt and the like.

SUMMARY OF THE INVENTION The present invention overcomes the difficulties noted above with respect to prior art devices by providing a preinsulated splicing connector which can be installed within the field with a minimal amount of additional equipment and which does not require the laborious task of building up a tape insulated sleeve over the splice. This is accomplished by means of a connector consisting of an insulated sleeve having therein a longitudinal passage and containing within such passage a fusible plug, which when properly heated, will join together conductors or other elements placed within a longitudinal passage. Fusion of the fusible plug can be caused either by the inclusion of a heating coil about the fusible plug or by the introduction of a heating coil about the outer portion of the insulated sleeve. In the embodiment in which the heating coil is provided within the insulated sleeve and about the fusible plug, ports are provided to the external surface of the insulating sleeve whereby electrodes may be coupled to the heating coil to activate it from an external source. Further, a socket is provided within the fusible plug to receive a temperature probe so that a determination can be made externally as to when fusion has taken place. A corona shield is provided within the insulating sleeve to protect against corona discharge. Further, a ceramic shield may be included to protect the insulating sleeve from high temperatures required to braze certain material together. It is therefore an object of this invention to provide a preinsulated splicing connector which can be employed to join at least one electrical conductor to a further conductor or other elements.

It is still another object of this invention to provide a preinsulated connector having an insulated sleeve and a plug of fusible material therein.

It is yet another object of this invention to provide a preinsulated connector having a heating element within the insulating sleeve thereof to provide for the coupling of conductors placed within such sleeve with a minimum amount of external equipment.

Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principles of the invention and the best modes which have been contemplated for carrying them out.

BRIEF DESCRIPTION OF THE DRAWING In the drawing in which similar elements are given similar reference characters:

FIG. 1 is a side elevation, in section, of a connector constructed in accordance with the concepts of the invention.

FIG. 2 is a side elevation, in section, of the connector of FIG. 1 showing two conductors to be joined placed within the connector and further showing the positioning of the temperature detector and power supply for operating the coil therein.

FIG. 3 is a side elevation of a further embodiment of the connector constructed in accordance with the concepts of the invention.

FIG. 4 is a side elevation, in section, of yet another embodiment of the invention constructed in accordance with the concepts of the invention.

FIG. 5 is a side elevation, in section, of still another form of the invention.

FIG. 6 is a side elevation of the connector of FIG. 1 showing the conductor coupled to a terminal pad.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIG. 1 there is shown a connector 10 constructed in accordance with the concepts of the invention. Connector 10 has an outer insulating sleeve 12 having a longitudinal passage 14 therethrough. At each end of the longitudinal passage l4- are enlargements forming cavities 16 for the receipt therein of conductors, or the like. Adjacent each of the cavities 16 is an external clamp 18 which will be employed'to seal the ends of the insulating sleeve 12 about the jackets of conductors or the like placed within the cavities 16. For shipment purposes, and to prevent dirt, moisture and the like from intrusion within the longitudinal passage 14, end caps 20 are provided. End caps 20 will be removed prior to the installation of conductors, or other members, within the cavities 16. Each of the cavities 16 terminates in a seal 22 which has an aperture 24 therein permitting the contact of the central conductor with the fusible plug 15 contained within longitudinal passage 14. The fusible plug 15 may be solder, brazing compound, or if the conductors are to be of sodium may be a-block of solid sodium placed within the longitudinal passage 14. A socket 26 is positioned within the longitudinal passage 14 and within the fusible plug 15 material for receipt therein of a temperature probe to be described below. A corona shield 28 extends over the entire length of the longitudinal passage 14 to protect the conductors placed within the connector 10 from corona discharge. A heater coil 30 is provided about the external portions of the longitudinal passage 14. The ends thereof are connected to terminators 32. Each of the terminators 32, found at the end of entry ports 34, receives therein one of the electrodes of an external power supply in order to cause the passage of current through the heater coil 30 and thus cause the heating of the fusible plug 15 material within the longitudinal passage 14. A further port 36 extends to the socket 26 for the placement therein of a temperature probe. Ports 38 are provided in the sleeve 12 adjacent the cavities 16. Adhesive materials and/or sealants are passed therethrough in order to adhere the conductor jacket to the sleeve 12. The sealing plugs (not shown) are employed to seal the

ports

34, 36 and 38 after the junction has been made in order to insure the integrity of the insulated sleeve 10.

Turning now to FIG. 2 there is shown the installation of the connector 10 to two sodium conductors 40. In this instance the longitudinal passage 14 will be filled with solid sodium 42. Firstly, the conductors 40 are square cut at their ends and placed in the cavities l6 abutting the seals 22. An adhesive material is pumped through the ports 38 to form a layer of adhesive about the outer surface of the conductors 40 and the inner surface of the cavities 16 of the insulating sleeve 10. The clamps 18 are then tightened about the conductors 40 to insure a good mechanical connection between the conductors 40 and the sleeve ends of the sleeve 10.

The inner current carrying conductors of the conductors 40 are placed adjacent the apertures 24 in the seals 22. Probes 44 coupled to power supply 50 are then inserted within the ports 34 and into contact with the terminations 32 of the heater coil 30. The probe 46 with a temperature detector 48 connected thereto is inserted within the port 36 and into the socket 26. Current will then be provided by the power supply 50 to probes 44 and thence to the coil 30 to cause heating of the fusible plug 42 within the longitudinal passage 14. As a result, the sodium plug 42 is fused to the sodium central current carrying conductor exposed in the apertures 24 of the seals 22 to form a unitary seal therebetween. The proper temperature for fusion will be monitored by means of the probe 46 and the temperature detector 48. When fusion has been completed probe 46 and the electrodes 44 will be removed from the

ports

36 and 34 respectively and port closures (not shown) will be affixed within the

ports

34 and 36 to seal them and insure the integrity of the sleeve 12.

Turning now to FIG. 3 thereis shown a variation of the device illustrated with respect to the FIGS. 1 and 2. In this embodiment an induction heating coil 52 is wrapped about the outer surface of the sleeve 12 and is connected to an induction heater 54. Sufficient heating will be caused within the fusible plug placed within longitudinal passage 14 (not shown) to cause fusion of the fusible plug to the conductors 40 placed within the ends of the sleeve 12. By employing this technique it is not necessary to insert port closures as is necessary with the device of FIGS. 1 and 2 thus insuring a completely moisture and dirt free splice.

Depending upon the type of material to be joined and the material from which the fusible plug is made greater heat may be required than possible with the device as shown with respect to FIGS. 1 and 2. In such instance the heating coil 56 is placed in direct contact with the fusible plug material placed within the longitudinal passage 14 as is shown in FIG. 4. This will provide a greater amount of heating than is possible in the offset arrangement of the heater coil 30 with respect to FIGS. 1 and 2. Further, in order to avoid ports 34 a breakoff lead 58 is provided to the coil 56 and extends out the end of the sleeve 12. After attachment to a power supply, such as power supply 50 of FIG. 2, and the fusing of the fusible plug, removable electrode 58 may be then broken off by suitable means and removed therefrom. Further, a rubber boot 60 may be positioned about the end of a conductor to be placed within the cavity 16 to provide additional moisture sealing for the splice.

Turning now to FIG. 5 there is shown a modification of the connector in order that the same may be used with conductors of metals such as copper, or aluminum. Assuming, for example, the conductors are aluminum, a brazing compound 62 may be placed within the longitudinal passage 14 not totally filling the same. Sufficient space will be provided within the longitudinal passage 14 to receive bare portions of the central conductors of the conductors to be joined. In such an arrangement a portion of the outer jacket of the conductor will be removed and the exposed central conductor will then be positioned through the aperture 24 in the seal 22 and into the longitudinal passage 14 adjacent the fusible plug material 62. As was described with respect to FIG. 2, adhesive material will be placed through the ports 38 about the conductors placed within the cavity 16 and the clamps 18 will be tightened up. By use of a power supply, such as 50 shown in FIG. 2, sufficient current will be built up in the coils 30 to cause the brazing material of the fusible plug 62 to fuse the ends of the conductors together. However, because of the additional heat required, in order that the brazing compound fuse, a ceramic shield 64 is inserted between the longitudinal passage 14 from the outer surface of the sleeve 12. As is shown, the ceramic shield 64 is placed within corona shield 28. In this manner the heat produced will not in any way effect the insulating sleeve 12 causing it to melt or producing any lesions which might otherwise effect its operation.

Referring now to FIG. 6 there is shown the manner in which the connector of FIG. 1 may be employed to join a conductor 40 to a terminal pad 66. The conductor prepared in the manner described above with respect to FIG. 5 is inserted into,

the cavity 16, for example, on the left side as is shown in FIG. 6, and a terminal pad 66 having a tapered screw threaded extremity 68 will be placed into the opposite cavity 16 on the right-hand side of the figure into the longitudinal passage 14 thereof. Clamps 18 will be tightened up to assure good mechanical connection between the connector 10 and the conductor 40 and the terminal pad 66. Heat will then be applied in the manner described with respect to the devices above noted to cause the fusible plug placed within the iongitudinal passage 14 to fuse conductor 40 to the terminal pad 66.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

lclaim:

1. A connector comprising: an insulated sleeve having a longitudinal passage therethrough for receipt therein of at least one conductor; an electrically conductive, fusible plug means positioned within said longitudinal passage; and selectively operable heating means juxtaposed about said fusible plug means within said insulated sleeve; said heating means when operated causing said fusible plug means to form a joint between said fusible plug means and a conductor placed in said longitudinal passage of said insulated sleeve.

2. A connector, as defined in claim 1, further comprising a corona shield juxtaposed intermediate said longitudinal passage of said insulated sleeve and the outer surface thereof.

3. A connector, as defined in claim 1, further comprising: heat shield means about said heating means to protect said insulated sleeve from the heat produced by said heating means.

4. A connector, as defined in claim 1, further comprising entry ports extending from the outer surface of said insulated sleeve to said selectively operable heating means for the insertion of means to operate said selectively operable heating means.

5. A connector, as defined in claim 4, further comprising: receptible means positioned in said fusible plug means; a temperature probe port extending from the outer surface of said insulated sleeve to said receptacle means; said temperature probe port permitting the insertion of a temperature probe into said receptacle means.

6. A connector comprising: an insulated sleeve having a longitudinal passage therethrough for receipt therein of at least one conductor; an electrically conductive, fusible plug means positioned within said longitudinal passage; and selectively operable heating means juxtaposed about said fusible plug means within said insulated sleeve in contact with said fusible plug means; said heating means when operated causing said fusible plug means to form a joint between said fusible plug means and a conductor placed in said longitudinal passage of said insulated sleeve.

7. A connector, as defined in claim 6, further comprising a corona shield juxtaposed intermediate said longitudinal passage of said insulated sleeve and the outer surface thereof.

8. A connector, as defined in claim 6, further comprising: heat shield means about said heating means to protect said insulated sleeve from the heat produced by said heating means.

9. A connector comprising: an insulated sleeve having a longitudinal passage therethrough for receipt therein of at least one conductor; an electrically conductive, fusible plug means positioned within said longitudinal passage; a corona shield juxtaposed intermediate said longitudinal passage of said insulated sleeve and the outer surface thereof; and selectively operable heating means juxtaposed about said fusible plug means; said heating means when operated causing said fusible plug means to form a joint between said fusible plug means and a conductor placed in said longitudinal passage of said insulated sleeve.

10. A connector comprising: an insulated sleeve having a longitudinal passage therethrough for receipt therein of at least one conductor; an electrically conductive, fusible plug means positioned within said longitudinal passage; a corona sleeve; said heating means when operated causing said fusible plug means to form a joint between said fusible plug means and a conductor placed in said longitudinal passage of said insulated sleeve.

Claims

10. A connector comprising: an insulated sleeve having a longitudinal passage therethrough for receipt therein of at least one conductor; an electrically conductive, fusible plug means positioned within said longitudinal passage; a corona shield juxtaposed intermediate said longitudinal passage of said insulated sleeve and the outer surface thereof; and selectively operable heating means juxtaposed about said fusible plug means and positioned about the outside of said insulated sleeve; said heating means when operated causing said fusible plug means to form a joint between said fusible plug means and a conductor placed in said longitudinal passage of said insulated sleeve.