US3368183A

US3368183A - Connector means and methods for relatively soft conductors

Info

Publication number: US3368183A
Application number: US561470A
Authority: US
Inventors: Watts William Sewell
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1966-06-29
Filing date: 1966-06-29
Publication date: 1968-02-06
Anticipated expiration: 1985-02-06
Also published as: DE1615613A1; SE307183B; NL6708488A; GB1142668A; ES342003A1

Description

W. S WATTS Feb; 6, 1968 CONNECTOR MEANS AND METHODS FOR RELATIVELY SOFT CONDUCTORS 4 SheetS-Sheet Filed June 29, 1966 m m Em V m Jr w w e S m w m M. w /IU Feb. 6,- 1968 w. s. WATTS 3,368,133

CONNECTOR MEANS AND METHODS FOR RELATIVELY SOFT CONDUCTORS Filed June 29, 1966 4 Sheets-Sheet 2 INVENTOR. William Sewell Watts Feb. 6, 1968 w sfwATTs 3,

CONNECTOR MEANS AND METHODS FOR RELATIVELY SOFT CONDUCTORS Filed June 29, -1966 4 Sheets-Sheet '3 [64 59 A? 1 j: f

INVENTOR. William Sewell Watts Feb. 6, 1968 wJ. WATTS ,3

CONNECTOR MEANS AND METHODS FOR RELATIVELY SOFT CONDUCTORS Filed June 29, 1966 4 Sheets-Sheet 4 Mil-Ml" INVENTOR. William Sewell Watts 3,36%,lfi3 Patented Feb. 6, 1968 3,368,183 CONNECTOR MEANS AND METHODS FOR RELATIVELY SOFT CONDUCTQRS William Sewell Watts, Harrisburg, Pa, assignor to AMP Incorporated, Harrisburg, Pa. Filed June 29, 1966, Ser. No. 561,470 16 Claims. ((31. 33998) This invention relates to a method and means for connecting electrical conductors formed of conductive materials which are relatively soft in a solid state and which may have liquid or semi-solid characteristics.

Over the years the principal material utilized for electrical conductors has been copper in one form or alloy or another. Aluminum has also been used but to a lesser extent. In devices utilized to connect, splice, terminate or otherwise mechanically and electrically join conductors, brass having platings of silver or gold and sometimes nickel or tin has been used. All of these materials are, however, relatively expensive and have, at times, been in short supply. These materials in the particular alloy of use are relatively hard and rigid, and to varying degrees depending upon the desired geometry of cable or device, are relatively difiicult to form. All of them have been used extensively because of low electrical resistivity.

Recently, interest has been revived in the use of materials which are significantly less expensive and more abundant than the aforesaid materials. One of these materials is sodium, in various forms and alloys. As compared with the copper alloy utilized in electrical conductors sodium is quite softv It is sufiiciently soft and ductile at normal temperatures to permit molding with the fingers and it can be readily extruded into wire or ribbon or other geometries with a simple hand press and die. It has a comparatively low melting temperature going to liquid at about 208 F. in a pure state and near that temperature in various alloys available for use. It has a characteristic of volumetric change which is about 2.7% at one atmosphere pressure between solid and liquid forms. Sodium is a light material as compared with copper and has a reported density at 60 F. of about 0.97 gram per cubic centimeter. It has an electrical resistivity at 68 F. of 4.9 micro-ohms per centimeter. In the range between 32 F. and its melting point its resistivity varies from 4.5 micro-ohms per centimeter to 6.75 micro-ohms per centimeter. Its resistivity is closely related to the thermoconductivity of the material. In a liquid state its resistivity rises to approximately 9.6 micro-ohms per centimeter and at 284 F. it is approximately 11 micro-ohms per centimeter.

The foregoing considerations generally indicate the utility of solid sodium in one form or another as a conductive material. There are other characteristics which however must be taken into consideration. One is that sodium is not stable in a normal environment and reacts with air, water and many other materials including metal such as copper. It must therefore be sealed against normal environment including air and moisture and consideration must be made as to the interface which will result by the imposition of conductors of one kind or another into contact with sodium.

From the foregoing it will be apparent to those skilled in the art that there are a number of problems attendant upon the use of sodium or sodium-like materials as conductors. It is an object of the present invention to provide a method and means of joining electrical conductors which have characteristics like that of sodium.

It is another object to provide a method and means for joining electrical conductors which include conductive material which is sufiiciently soft and ductile at normal temperatures that it can be molded with the fingers.

It is a further object of the invention to provide a connection of electrical conductors having characteristics requiring protection from an environment which includes air and moisture.

It is yet another object of the invention to provide a connection of electrical conductors which provide an interface between the conductors to be connected which is relatively clean and free of substances other than that of the material of the conductors.

It is an object of the invention to provide a simple and inexpensive means of joining electrical cable which includes material which is unstable in normal environments.

The present invention obtains the foregoing objectives and overcomes the various difiiculties inherent in joining electrical cable comprised of conductive material having the general characteristics sodium by utilizing the conductive material of the cable to form the interface between the cables, Means are contemplated which physically hold and seal two or more cables in proximity with a portion or portions of the cables positioned out of the path of conduction employed in the circuit formed between cables. Further means are provided to plug or cut into the cables down within the means which hold and seal the cables to create a void therebetween and to expose fresh and clean surfaces of the material of an area sufiicient to define a resistance path at least equal to that of the smallest size cable to be used. Finally, it is contemplated that the portion or portions of the cable material not in the conductive path be compressed to cause such material to he extruded into the void under sulficient pressure to intermix with the material of the opposite cable or cables and thereby form an interface between cables comprised solely of the material of the cables. The invention embraces in one sense a method for accomplishing a desired connection and in another sense a variety of means for accomplishing the desired connection, as Well as the connection itself. Such means are in the more standard forms such as that of a tap, and a splice which exemplify the article of the invention.

In the drawings:

FIGURE 1 is a perspective view of a connector tap electrically and mechanically joining a supply cable to a feeder cable;

FIGURE 2 is a longitudinal section taken through lines 22 of FIGURE 1 showing the cables as connected;

FIGURE 3 is a cross-sectional view of the tap of FIG- URE 1 showing the elements thereof prior to termination but after the connector has been physically attached to the cables;

FIGURE 4 is a view of the tap as shown in FIGURE 3 following a second step in the procedure for accomplishing termination;

FIGURE 5 is a view of the tap as shown in FIGURE 3 and FIGURE 4 following the final step with the termination between cables being completed;

FIGURE 6 is a longitudinal view in section showing a splice embodiment of the connector of the invention;

FIGURE 7 is an end on view of the type of splice shown in FIGURE 6;

FIGURE 8 is an abbreviated showing of an alternative embodiment of a connector tap;

FIGURE 9 is a side view of the tap of FIGURE 8; and

FIGURE 10 is an abbreviated showing of still another embodiment of the invention in a multiple connector tap.

Referring now to FIGURE 1 a connection of cables is shown as 10. The cables are shown as 12 and 14 representing a main or supply cable and a tap otf or feeder cable respectively. The object of the connection is to electrically and mechanically join the cables such that electrical energy carried in 12 is supplied to 14 and from there to equipment serviced by 14. The cables are shown as being of the same diameter to include an outer jacket I comprised of an insulating material such as polyethylene and an inner core of conductive material C comprised of a relatively soft and ductile conductive material such as sodium.

' The connector 16 is comprised of a body including two halves 18 and 2% which are hinged or otherwise joined at the top as by a pin 22 and arranged to be forced and held together by means applied through apertures 24 located opposite to the hinged end. This is shown in FIGURE 3 by numerals 2 5 representing bolts applied through the apertures. The inner surfaces of 18 and 12.0 are shaped as shown to accommodate the

cables

12 and 14 and to include mating faces which join as at 26. These faces contain intermating projections and recesses 28 and 2% which are made to run horizontally and vertically to surround the site of interconnection of the materials of the two cables. This is shown in FIGURE 2. In the center of each half is another intermating projection and recess which is shown as at 31. Relative to FIGURE 1 the mechanism for effecting a termination of the conductive material of the two cables is shown generally as at 30. As can be seen from FIGURES l and 2 the site of interconnection between the two cables is surrounded by portions of the halves 18 and adapted to seal such site from the environment of use.

In practice the halves 18 and 2.0 are supplied in a position opened like a clam shell with the bulk of terminating mechanism 34 carried in half 26 in the position shown folded and closed in FIGURE 3. As appears in FIGURE 3 this mechanism includes in half 18 an eyelet member 32 which is affixed thereto in the center thereof to receive a threaded bolt 34 which extends from the inside of 26 over between the cables into and through 18. Bolt 34 is joined to a cutting member 33. A generally cylindrical

cavity including portions

39 and 41 extends across the halves to define a passageway of movement for 38. The leading edge of 33 is beveled as at 40 to define a cutting edge capable of cutting and penetrating the jacket I and conductive material C of the cables. This bevel is directed inwardly so as to guide the material being cut into 38 which in the embodiment shown is cylindrical and in the one end closed to form a receptacle. Centered in 20 is a threaded eyelet member 42 adapted to receive and hold a bolt 44 having attached thereto a nut'46 which is adapted to be turned to drive the bolt 44 axially and to drive a sealing member 48 attached to the end thereof inward. The interior of eyelet 32 is not threaded but is rather of a diameter substantially greater than that of 34 to permit the insertion of 34 without nut 36 through 32 and through 18 as it is folded down from the open position to the position shown in FIGURE 3.

During installation with the

halves

18 and 20 in the open position the interior surfaces thereof including the

portions

26, 28, 29 and 31 are all preferably coated with a cement or adhesive of a type which will not react with the conductive material C employed in the cable. The adhesive or cement is preferably formulated to be relatively quick acting in terms of setting and curing. With the blocks so prepared the assembly is attached to the cable by placing the cable 12 into the matching recess of half 20 and then placing the cable 14 in its matching recess in 263 with the bolt 34 protruding between the cables and with the portion 31 extending therebetween. The half 18 is then folded over with the bolt 34 being made to fit through 32. The members shown as are then applied and tightened to lock the two halves together.

As a preferred practice the application of adhesive or cement may be made suitably in advance of the d application of the connector to the cables so that partial curing will have already taken place at the time of application. Shortly after the installation to the point shown in FIGURE 3 the nut 36 may be applied to the bolt 34 and then turned down until the element 38 has been caused to move to the position shown in FIGURE 4 cutting through the cable jacket I and conductive material C of each of the cables to create the cavity or void therebetween as shown in FIGURE 4. Thereafter the element 46 maybe turned until 48 is forced hard in against the ledges 43 at the end of the cavity portion 41. At this point the cavity will be sealed by disc 48 on one side and by the rear of 38 on the other side.

As the next step and referring back to FIGURE 2 the cut end of cable 14 is then fitted with a member shown as 59 which includes a head 52 faced to be turned by a wrench or like device and a forward portion 54 containing threads 56 which bite into the inner surface of the jacket I. As 50 is threaded into the end of 14 the conductive material C is extruded to fill the void between the two cables in the center of the connector to force the material of cable 14 into the material of cable 12. FIGURE 5 shows an end section of the interface between the two cables and FIGURE 2 shows the interface in section viewed from the side. As can be discerned the two cables are electrically joined through a quantity of conductive material which is substantial and through a surface area which is also substantial relative to the cross-sectional areas of either the cables. The interface between the material of the cables is due to extrusion and since it is made through a surface which has been recently cut in a sealed environment it is free of oxidation products and is relatively clean. The material filling the void between the cables is under some pressure which will maintain the interface between the two materials. In the event that the conductive material becomes liquid the connection will still be maintained.

As will be apparent, an electrical connection has been provided between two cables without the imposition of separate and different conductive material. A mechanical and sealed connection of the cable has also been provided. In use it is preferred that the

halves

18 and 20 be of a plastic material which will not react with the particular conductive material of the cables, one such material being the same type of polyethylene used for jacketing the cables. The

elements

32 and 42 are also preferably of a plastic material. The bolt members 34 and 44- and

elements

36, 46 and 4-8 may be either plastic or metal. It is contemplated that the cutting member 38 be of a material sufficiently hard to maintain its cutting edge to penetrate and cut the cables as heretofore indicated. The I member is preferably of a plastic material such as polyethylene.

Having now detailed a general embodiment of the invention showing the method and means thereof for joining cable, several other forms will be described. FIG- URE 6 shows a splice of two

cables

58 and 59 which are each of the construction heretofore described with respect to

cables

12 and 14. The splice 60 includes a body member 62 which may be of the form discussed previously made to include an axial bore 64 extending therethrough to accommodate cable 59 and a bore 68 generally parallel to 64' to accommodate cable 58. In this embodiment the cables are fitted within the bores 64 and 66 the body member 62 is secured to lock and seal such cables in place having been prepared with an adhesive material for this purpose. Next a cutting mechanism such as 70 is operated in the manner heretofore described to create a void between the two cables and then members 72 and '74 are applied to effect the extrusion mentioned to -fill such void and form an interface between the two cables.

In FIGURES 8 and 9 another embodiment of the invention is shown wherein the cables to be joined are positioned in an overlying relationship with one cable being extended across the other cable. In FIGURES 8 and 9 an embodiment for a connector tap is shown wherein a main supply cable 80 is tapped by a feeder cable 82. In this embodiment the same general details heretofore discussed may be utilized to mechanically join the two cables together and to seal the zone of contact. The body 84 is made to include bores to accommodate the cables and it may be made in halves as heretofore discussed. The bores in 84 are however positioned in different planes so that the cable 82 overlies the cable 80. The cutting mechanism 86 which may be of the same construction previously discussed is made to intersect the cables as shown in FIGURE 8. The end of 82 is positioned as shown to be fitted with a member 88 which operates to extrude the conductive material of 82 into the void created by operation of 86.

FIGURE shows yet another embodiment wherein a main supply cable of 90 is tapped by three

smaller feeder cables

92,, 94 and 96-. Again the general principles discussed may be utilized to develop the details for a connector body structure 106. In this embodiment the feeder cables are made to overlie the main cable and the cutting mechanisms for each feeder cable are made to penetrate through the center of the cables to define voids or spaces between the cables forming the connection. These are shown as 102, 104 and 106. After the operation of these

mechanisms members

108, 110, 112 may be applied to extrude the cable material and to fill the voids defining the interfaces between the cables.

In the exemplary embodiments heretofore discussed a cylindrical cutting member has been disclosed. It is contemplated that cutting members of other configurations may be utilized to increase the surface area between the cables which are joined without diminishing the crosssectional thickness of either of the cables to the extent shown as in FIGURE 2. The technique of extrusion has been shown to have been accomplished through the application of a threaded screw like member. It is also contemplated that the cut end of the cable to be terminated may be capped by a screw member like 50 and a further force applied to the cable between such cap and the zone of interface by a hand tool or by an additional screw member made to compress the cable in between and thus provide the extrusion required. This latter embodiment may be used separately or in conjunction with the version taught if application is required in extremely cold environments.

The invention has been taught relative to a use with a conductive material such as sodium. It is also contemplated that the invention may be utilized with conductive materials having similar properties and even with semiliquid materials or liquid materials.

Having now described my invention in terms intended to enable its preferred practice I define it through the appended claims.

What is claimed is:

1. In a connector device for mechanically and electrically joining electrical cables which include a conductive material having the general characteristics of sodium, a body member for housing a first and at least a second cable, said body member having means to mechanically join said cables and to seal the housed surfaces of said cables, means to cut through portions of each cable to define a common void therebetween exposing the conductive material of each cable, means to extrude the conductive material of at least one of said cables to fill said void and form a body of conductive material extending between the conductive materials of the two cables whereby to effect an electrical connection thereof.

2. The device of claim 1 wherein said body member includes interior surfaces disposed to receive at position said cables in a side-by-side relationship.

3. The device of claim I wherein said body member includes interior surfaces positioned to receive and position said cables in a crossing relationship.

4. The device of claim 1 wherein said body member includes interior surfaces disposed to receive and position said cables with the end of at least one cable exposed and accessible.

5. In a connector device for mechanically and electrically joining electrical cables of the type having a conductive material which is soft and ductile to an extent that at ambient temperatures it can be molded with the fingers or readily extruded with a simple hand press and die, housing means for positioning at least two cables to be joined with portions of the cables proximate each other including, means for physically holding said cables in such position and for sealing the said cables against the environment of use, means adapted to be driven to cut through said cables at said proximate portions to create a space therebetween bounded in part by areas of cable material freshly exposed and a member operable to extrude conductive material from one of said cables into said space to form an interface between the conductive materials comprised solely of the conductive materials of said cables whereby to electrically connect one cable to the other cable.

6. The device of claim 5 wherein at least one of said cables has a cut end with said housing means including means to position said cut end proximate to the said member operable to extrude conductive material.

7. The device of claim 6 wherein said cable includes an outer sheath of insulating material and the said member is inserted into said cut end and includes threads adapted to bite into said material as said member is rotated whereby to provide compression and extrusion of the cable conductive material.

8. The device of claim 5 wherein the said housing means includes intermating interior surfaces carrying an adhesive material adapted to bond said housing to said cable to provide said holding and sealing.

9. The device of claim 5 wherein said housing means is formed of halves joined at one end with each half being relieved interiorly to accommodate a portion of each cable whereby to permit said halves to be closed together to provide said holding and sealing by a pressure engagement with said cables.

10. In a device for joining electrical cables of the type having a conductive material which is less stable than that of copper or aluminum in a normal environment means including a body member having interior surfaces of a configuration to receive the exterior surfaces of portions of said cables, means between said surfaces to seal the said portions against an outside environment and means to penetrate said cables exposing portions of conductive material therein to each other and means for extruding conductive material of one cable into the other cable whereby to provide a continuous path of conductive material between the two said cables sealed against the outside of said device.

11. The device of claim 10 wherein the said body member includes a bore extending therein and said means to penetrate includes a cutting edge and driving means coacting with said body member and operable to drive said cutting edge through said cables.

12. The device of claim 11 wherein said means to penetrate includes a receptacle attached to and following said cutting edge to gather and hold the cut portions of said cable.

13. The device of claim 11 wherein there is further included means operable to follow said cutting edge in said bore to seal the cut area of said cables.

14. In a method of joining one electrical cable to another electrical cable the steps comprising positioning said one cable with an end thereof and a segment there of proximate the second cable, effecting a void between said cables by removing material therefrom including conductive material from each of said cables and then extruding material from one of said cables into said void to provide a path of conductive material continuous between the two said cables.

15. In a method of joining electrical cables of a type having a conductive material like that of sodium the steps comprising positioning said cables in an adjoining relationship with one of said cables having a severed end near the joined position, holding said cables in said position, forming a space between the cables at the joined position which exposes conductive material of one cable to the conductive material of the other cable and then applying pressure to the severed end of said one cable to force the material therein into said space to form a body of continuous conductive material between said cables to provide an electrical connection thereof.

16. In a method of forming a connection of conductive material of the type having the general characteristics of sodium the steps comprising positioning one body of con ductive material proximate to another body of conductive material, removing portions of the material of each body of material at the point of proximity to expose a fresh material surface and then applying pressure to one body of material to force the fresh surface of said body of material at the point of removal of material to move into a firm engagement and interface with the fresh surface of the other body material at the point of removal of material References Cited UNITED STATES PATENTS 833,290 10/1906 Betts 174-120 3,154,363 10/1964 Will 33999 MARVIN A. CHAMPION, Primary Examiner.

I. H. MCGLYNN, Assistant Examiner.

Claims

1. IN A CONNECTOR DEVICE FOR MECHANICALLY AND ELECTRICALLY JOINING ELECTRICAL CABLES WHICH INCLUDE A CONDUCTIVE MATERIAL HAVING THE GENERAL CHARACTERISTICS OF SODIUM, A BODY MEMBER FOR HOUSING A FIRST AND AT LEAST A SECOND CABLE, SAID BODY MEMBER HAVING MEANS TO MECHANICALLY JOIN SAID CABLES AND TO SEAL THE HOUSED SURFACES OF SAID CABLES, MEANS TO CUT THROUGH PORTIONS OF EACH CABLE TO DEFINE A COMMON VOID THEREBETWEEN EXPOSING THE CONDUCTIVE MATERIAL OF EACH CABLE, MEANS TO EXTRUDE THE CONDUCTIVE MATERIAL OF AT LEAST ONE OF SAID CABLES TO FILL SAID VOID