US3835241A

US3835241A - Adaptor for modifying connector to accommodate smaller conductors

Info

Publication number: US3835241A
Application number: US00268147A
Authority: US
Inventors: J Masterson; J Lawler
Original assignee: General Cable Corp
Current assignee: General Cable Corp
Priority date: 1972-06-30
Filing date: 1972-06-30
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10

Abstract

Communication cables are connected together by inserting end portions of insulated conductors into connectors having inwardly projecting tangs, and the connectors are then compressed to grip the wires and force the tangs to cut through the insulation and part way through the wires to hold the wires firmly in the connector and in an electrical circuit with each other. Such standard connectors could not be used with wires smaller than No. 26 AWG. This invention places an adaptor in the connector as a stop to limit the flattening of the connector against the wires, and to prevent the connector sleeve from closing tight enough to cut through wires as small as No. 28 AWG. The range of wire sizes that the connector can be used for is thereby extended.

Description

United States Patent [191 Masterson et al.

[ ADAPTOR FOR MODIFYING CONNECTOR- TO ACCOMMODATE SMALLER CONDUCTORS Inventors: Joseph B. Masterson, Carteret; John D. Lawler, Bayonne, both of NJ.

Assignee: General Cable Corporation, New

York, NY.

Filed: June 30, 1972 Appl. No.: 268,147

[56] References Cited UNITED STATES PATENTS 3,566,006 2/l97l Metcalf 174/87 X 174/8 7, 84 c, 94 R, 90; 223' R, 276 R; 29/628,

[11] 3,835,241 [451 Sept. 10,1974

Primary ExaminerDarrell L. Clay [5 7] ABSTRACT Communication cables are connected together by inserting end portions of insulated conductors into connectors having inwardly projecting tangs, and the connectors are then compressed to grip the wires and force the tangs to cut through the insulation and part Way through the wires to hold the wires firmly in the connector and in an electrical circuit with each other. Such standard connectors could not be used with wires smaller than No. 26 AWG. This invention places an adaptor in the connector as a stop to limit'the flattening of the connector against the wires, and to prevent the connector sleeve from closing tight enough to cut through wires as small as No. 28 AWG. The range of wire sizes that the connector can be used for is thereby extended.

9 Claims, 7 Drawing Figures proceeds.

BACKGROUND AND SUMMARY OF THE INVENTION Communication cables, such as are used for telephones, are made with large numbers of pairs of small wires, and it is advantageous to use small wires because this increases the number of circuits for a cable of given size. In practice, however, No. 26 wire has been the smallest size in general use for telephone work and the reason for this has been that No. 28 wire breaks easily when being handled for connections and standard B connectors could not be used with No. 28 wire because the connectors frequently cut all the way through the wires.

The invention extends the range of wire sizes with which standard connectors can be used by inserting an 7 adaptor into the inner sleeve of the connector. With this adaptor, the standard connector can be used with No. 28 wire; and cut through and -breaking is not as common with the No. 28 wire as was formerly the case with No. 26 wire.

The invention is important at this time because the installation of more conduits for telephone cables in cities is very expensive, yet there is demand for more circuits. By pulling out the old cables with No. 26 wire and installing new cables with No. 28 wire, the number of circuits that can be obtained in an existing conduit is increased up to approximately 50 percent and with great saving in cost as compared with installing new conduits. y

In the preferred construction of this invention, the adaptor is a stop installed in the inner sleeve of the connector to resist deformation of the connector beyond 'FIG. 3 is an elevation of the connector shown in FIGS. 1 and 2 but with the outer sleeve of FIG-2 rethe line 7-7 of FIG. 3.

a predetermined limit during the crimping process. The

connector is a sleeve into which the wires that are to'be connected are inserted. The adaptor can be soft copper wire of approximately No. 19 AWG and the wire is bent to the shape of a thin letter U. The wires to be connected are inserted into the'open part of the U and the connector is then compressed to bring tangs of the sleeve into contact with the adaptor and the wires to be connected. The soft malleable material of the adaptor is gripped by tangs of the sleeve and at the same time the adaptor acts as a stop to limit the inward displacement of the sides of the sleeve so that the cut through of the tangs on the wires is limited and the wires are not completely severed by the tangs.

One outstanding advantage of the invention is that it does not require new connectors. It expands the range of wire size for which standard connectors already in general use are suitable. v

Other objects, features and advantages of the invention will appear or be pointed out as the description BRIEF DESCRIPTION OF DRAWING In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views;

FIG. 1 is an elevation of astandard connector with which the adaptor of this invention is combined;

FIG. 2 is an elevation of the connector shown in FIG. 1 but with the plastic envelope removed to expose the outer sleeve of the connector;

. the sleeve wire of No. 19 gauge DESCRIPTION OF PREFERRED EMBODIMENT FIG. 1 shows a connector 10 which includes a plastic envelope 12 which covers the connector and which has an open lower end 14 through which

wires

16 and 18 extend into the connector. These insulated

wires

16 and 18 are the wires which 'are joined together by the connector 10.

FIG. 2 shows the connector 10 with the envelope l2 removed so as to expose a soft metal outer sleeve 20 which consists of a shell 22 folded in a tubular shape, and having a seam along the line 26..This line 26 is straight along part of its length and has projections and recesses along other parts of its length so that projections of one side of the seam fitinto the recesses on the other side to keep the opposite edges of the sleeve from moving longitudinally (up and down in FIG. 2) with respect to one another. The plastic envelope 12 is applied over the sleeve 20.

FIG. 3 shows the connector when the sleeve 20 is removed. An inner sleeve 30, which is made of hard metal, has numerous openings 32 formed in both sides.

FIG. 3 shows the

insulated wires

16 and 18 extending for the full length of the inner sleeve 30. Tangs from the different openings 32 extend through the insulation of the

wires

16 and 18 and cut into the paired wires within the insulation when the inner sleeve 30 is flattened. The connector thus far described is a conventional B connector and is described in U.S. Pat. No. 3,507,977.

This invention modifies the standard connector by inserting an adaptor36 into the inner sleeve 30. This adaptor, shape of which is best shown in FIG. 4, is of a size to fit into the inner sleeve 30 and to extend across the width of the sleeve before the perforated sides of are collapsed into contact with the

wires

16 and 18.

The adaptor 36 is preferably made of soft copper (AWG). The adaptor 36 is in the shape of athin letter U, which is in an inverted position in the drawing. The open end of the U is at the end of the inner sleeve 30 through which the

wires

16 and 18 are inserted into the connector. In the preferred construction, the lower ends of the adaptor 36 have tapered faces 38 which provide a flaring entrance for easier insertion of the

wires

16 and 18 into the lower end of the sleeve 30.

The

wires

16 and 18 are pushed up into the inner sleeve 30 as far as they will go and the curved portion at the end of the adaptor 36 serves as a stop to limit the rounded by the outer sleeve 20, is pressed between the jaws 41 and 42 (FIG. 7) of a closing tool which is conventionally a ratchet clamp with a spring for limiting maximum pressure exerted on the connector. FIG. 7 shows in

phantom clamping jaws

41 and 42 exerting a maximum force F which compresses the connector and in doing so flattens the inner sleeve 30 so as to cause the tangs 34 to pierce insulation 44 and cut into'the 'metal of thewires l6 and 18.

tion, the lengths of the tangs 34 are approximately 13 mils. Wire diameters for No. 26 and No. '28 AWG wire are 15.9 and 12.6 mils, respectively. The tangs have a mean cut-through of the wire of approximately 53 percent with standard deviations of approximately 17 percent.

. The preferred embodiment of the invention hasbeen illustrated and described, but changes and modifications can be madeand some features can be used in different combinations without departing from the invention as defined in the claims.

What is claimed is: i 1. An electrical connection comprising a flattened inner metal sleeve enclosing the ends of wires that are connected together in an electric circuit, tangs extending inwardly from the sleeve and engaging and going FIG.,7shows how the adaptor 36, which originally fit loosely into the sleeve 30', acts as a stop to limit distortion of the cross-section of-the sleeve'30. The crosssection of the sleeve 30 isdistO'rted to permit its flat faces to move closer together so that the tangs 34 can move into contact with and pierce the

wires

16 and 18 and the surfaces of the adaptor 36. Thus the adaptor 36 is anchored in the sleeve 30 while serving as a stop to, prevent the tangs 34 from cutting through the

wires

16 and 18. v

With the sides of the sleeves 30 pressed firmly against the adaptor 36, the force F available from the ratchet clamping tool cannot move the front'and back faces of the sleeve 30,, designated generally by the

reference characters

51 and 52, any closer together. Thus the adaptor 36 limits the percentage of cut through by the tangs 34 on the wires 16 andjl8; and even though the wires 16 and l8are 28-.gauge, the sleeve 30 cannot be,

ing the extent of the wires into the connector. Also,

even though the inside of the inner sleeve 30 is to a large extent obstructed by having the-adaptor 36 in the sleeve, the tapered end faces 38 provide a flaring entrance so that the wires can be inserted into the sleeve just as easily as if the adaptor 36 was not there.

It will be understood, however, that the adaptor 36 can be made with other shapes. It can be made in two parts with each part located along a differentside of the sleeve but with no connection between the parts; or the connection can be other than that shown. The essential feature of the connector 36 is that it be of a size that.

can be inserted into the sleeve into which the wires 16 and l8gare to be placed; and that the adaptor 36 be made of material which resists the pressure of the clamping tool after the tangs 34 have pierced the

wires

16 and 18. It is not essential that the adaptor 36 be made of metal or that'it be a conductor of electricity into the wires securing thewires therein and connecting the wires in an electric circuit withv one another, adaptor means 'within the sleeve, said adaptor means including abutment material-adjacent to the wiers but not one of the wires that are connected together in the electric circuit, the abutment means being of a crosssection larger than that of the wires and constituting a stopv limiting the flattening .of the sleeve causing the tangs to contact with said wires and preventing cut- .through of the wires by the tangs, and an outer sleeve fitting over the flattened inner sleeve.

.2. The connection described in claim 1 characterized by the tangs being formed of metal displaced by piercing openings through a side of the inner sleeve, both the wires being secured in the sleeve by being pierced by the tangs, and electrical insulation surrounding the outer sleeve.

3. The connection described in claim 2 characterized by the tangs extending inward from flattened sides on I both sides of the inner sleeve and the adaptor being soft wire of larger gauge than the wires that are connected.

4. The connection described in claim 1 characterized by the adaptorbeing a piece of soft wire shaped in the form of a narrow U with the sides of the Uextending through-the sleeve between the sides of the sleeve and the wires that are connected together by said connector, with the bent end of the 'U being at the other end of the sleeve from that through which the wires are originally inserted into the inner sleeve and having tapered. faces at the free ends of the U in angular relation that provide a flaring entrance between them for the wire to enter the sleeve.

5. The connection described in claim 1 characterized by the inner sleeve being a metal that is a good conductor of electricity, the tangs being formed of material displaced from openings pierced through flattened sides at both the top and bottom of the inner sleeve and having a length of about l3 mils, the wires to be connected being wire of No. 26 and No. 28 gauge (AWG) with insulation on the wire pierced by the tangs, the tangs having a mean cut-through of the wire of approximately 53 percent with standard deviations of approximately l7'percent, the adaptor being a length of soft copper wire of No. 19 gauge (AWG) with the length of the copper wire bent to the shape of a narrow U, the insulated wires being located side by side at a region approximately mid way across the width of the inner sleeve and the sides of the U being located beyond the insulated wires in the direction of the width of the inner sleeve, the copper wire of the adaptor serving as the stop.

6. The connection described in claim 1 characterized by the tangs being formed of metal displaced by piercing openings in both sides of the inner sleeve, the outer sleeve having a seam with adjacent edges extending generally lengthwise of the inner sleeve and having said edges shaped to interlock with one another to prevent each edge of the outer sleeve from moving lengthwise of the inner sleeve independently of the other edge.

7. The connection described in claim 6 characterized by the inner sleeve being made of hard metal and the outer sleeve being made of soft metal.

8. The connection described in claim 6 characterized by an outer envelope of electrical insulating material that fits over the outer sleeve and that holds the outer sleeve in assembled relation with the inner sleeve.

9. The connection described in claim 8 characterized by the outer envelope being of generally tubular shape and closed at its upper end and made of plastic that stretches to fit over the outer sleeve, said outer envelope being longer than the sleeves and the adaptor, and said outer envelope contracting at its lower end under the lower ends of the sleeves and adaptor to fully insulate the connector.

Claims

1. An electrical connection comprising a flattened inner metal sleeve enclosing the ends of wires that are connected together in an electric circuit, tangs extending inwardly from the sleeve and engaging and going into the wires securing the wires therein and connecting the wires in an electric circuit with one another, adaptor means within the sleeve, said adaptor means including abutment material adjacent to the wiers but not one of the wires that are connected together in the electric circuit, the abutment means being of a cross-section larger than that of the wires and constituting a stop limiting the flattening of the sleeve causing the tangs to contact with said wires and preventing cut-through of the wires by the tangs, and an outer sleeve fitting over the flattened inner sleeve.

2. The connection described in claim 1 characterized by the tangs being formed of metal displaced by piercing openings through a side of the inner sleeve, both the wires being secured in the sleeve by being pierced by the tangs, and electrical insulation surrounding the outer sleeve.

3. The connection described in claim 2 characterized by the tangs extending inward from flattened sides on both sides of the inner sleeve and the adaptor being soft wire of larger gauge than the wires that are connected.

4. The connection described in claim 1 characterized by the adaptor being a piece of soft wire shaped in the form of a narrow U with the sides of the U extending through the sleeve between the sides of the sleeve and the wires that are connected together by said connector, with the bent end of the U being at the other end of the sleeve from that through which the wires are originally inserted into the inner sleeve and having tapered faces at the free ends of the U in angular relation that provide a flaring entrance between them for the wire to enter the sleeve.

5. The connection described in claim 1 characterized by the inner sleeve being a metal that is a good conductor of electricity, the tangs being formed of material displaced from openings pierced through flattened sides at both the top and bottom of the inner sleeve and having a length of about 13 mils, the wires to be connected being wire of No. 26 and No. 28 gauge (AWG) with insulation on the wire pierced by the tangs, the tangs having a mean cut-through of the wire of approximately 53 percent with standard deviations of approximately 17 percent, the adaptor being a length of soft copper wire of No. 19 gauge (AWG) with the length of the copper wire bent to the shape of a narrow U, the insulated wires being located side by side at a region approximately mid way across the width of the inner sleeve and the sides of the U being located beyond the insulated wires in the direction of the width of the inner sleeve, the copper wire of the adaptor serving as the stop.