US3794959A

US3794959A - Cable connector with strain relief

Info

Publication number: US3794959A
Application number: US00200443A
Authority: US
Inventors: G Kamolz
Original assignee: International Standard Electric Corp
Current assignee: Alcatel Lucent NV
Priority date: 1970-10-22
Filing date: 1971-11-19
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: CA972440A; DE2051914A1; FR2111475A5

Abstract

A cable connector assembly is provided. It incorporates cavities and contact elements for terminals of wires forming a cable and includes a cavity into which a strain relief rod may be inserted. The rod supports a pair of spaced bosses between which a cable tie can be used to hold the wires and thus translate strain on the wires to the strain relief rod.

Description

United States Patent Kamolz Feb. 26, 1974 CABLE CONNECTOR WITH STRAIN RELIEF Primary Examiner-Richard E. Moore Attorney, Agent, or FirmC. Cornell Remsen, Jr; [75] Inventor. Gerd Kamolz, Stuttgart, Germany James B Raden; Delbert P Warner [73] Assignee: International Standard Electric Corporation, New York, N.Y.

[22] Filed: Nov. 19, 1971 57 B T [21] Appl. No.: 200,443

A cable connector assembly is provided. It incorporates cavities and contact elements for terminals of [52] US. Cl 339/103 M wires forming a cable and includes a cavity into which [51] ll lt. Cl H01! 13/58 a Strain relief rod may be inserted The rod supports a [58] Field of Search 339/102, 103, 104, 105, 106, pair of spaced bosses between which a cable tie can be 339/107 used to hold the wires and thus translate strain on the wires to the strain relief rod. [56] References Cited FOREIGN PATENTS OR APPLlCATlONS Germany 339/104 7 Claims, 6 Drawing Figures PATENTEH 3.794.959

Mill/114W Fig.3

4 6 Fig. 4A

INVENTOR G. KAMOLZ MJ%/ W ATTORNEY CABLE CONNECTOR WITH STRAIN RELIEF The present invention relates to a cable connector assembly having contact elements housed in insulator bodies thereof, and with connecting wires mounted thereto. It relates further to a device for effecting strainrelief for terminal wires terminating in the cable connector and finds particular utility in communications engineering.

Flat type cable connectors are known in which the contact elements are housed in corresponding cavities provided in two shell-type plug or receptacle halves, with the strain relief of the wires either being provided within the plug or receptacle halves or from the outside on the cable-introduction side, in the form of two cable clamps capable of being screwed to one another. In the case of multi-contact electrical connectors the arrangement of a wire strain relief is accompanied by difficulties, because the wires extending through the insulator bodies are distributed over a relatively large surface area. For this reason arms are mounted on the longitudinal sides of the shell having the smallest spacing between one another, which first of all extend straight forward for a certain distance, and are then bent off towards the center for being widened up to the form of cable clamps. This type of cable strain relief, however, is unsuitable for use in cases where the contact elements within the insulator body of the cable connector are of the interchangeable type.

Cable strain relievers mounted in the way described above have a detrimental effect upon the free access to the contact elements, especially in cases where they are to be inserted into the insulator body with the aid of a sleeve-shaped or tubular tool, or in cases where individual ones thereof are to be extracted subsequently thereto. Of course, it would be possible to provide in such cases a strain relief of the type disclosed in the shoven 2). This cable strain relief consists of an angular member, the one limb of which is provided with a bore adapted to the diameter of the thread on the cable introduction side, and is mounted to the casing by tightening the rear nut assembly, and with the other rectangularly bent-off limb thereof being bent once at its front end to such an extent that the cable is supported at this point and, on the other hand, comprises one or more slots next to this supporting point, for receiving cable clamps which, with the aid of clamping screws, enable the mounting of the cable thereto. This cable holding device, however, is intended for use in connection with circular cable introductions, and is thus not suitable, without modification, for cable connectors having cross sections other than only circular ones.

This is also the case in another conventional type of strain relief relating to electrical connectors of the circular type. In this case there is provided an arm forming one part with a tubular sleeve provided with an inside thread which is mounted at the connecting end of the connector to the housing by way of screwing. This holding arm, however, is of the internally bent type. In one such embodiment, free access to the contacts is provided in that the holding arm points rectangularly to the outside, but normally the cable connectors are used with respect to wire bundles extending straight forward, and a wire strain relief of the rectangular type in the cable connector, would have extremely disturbing effects. Under tight spacial conditions it could not be used at all.

In view of the aforementioned difficulties, it is an object of the invention to provide a simple device of low weight for the wires of cable connectors to which the wires can be mounted in a strain-relieved fashion and permitting free access for replacing contact elements if necessary. A further object is to provide that the device for mounting the wires shall be suitable for use in electrical connectors having any type of cross section.

According to the invention the foregoing objects are attained in that on the rearward facing surface of an insulator body surrounded by a frame or a shell and housing the contact elements, or on the shell itself there is arranged a pin for supporting the wire bundle, and to which the individual wires of the bundle are attached by means of a tie strap or lacing tape.

In order that the individual wires of the bundle can be easily arranged around the cable wire supporting pin, it is provided that the supporting pin is inserted with its mounting end, for example, in the contact cavity of the insulator body, which is arranged centrically and provided with a bayonet coupling sleeve.

An easy insertion of the supporting pin is effected in that the end of the supporting pin as mounted in the insulator body, is provided with a collar resulting from a conical recess ahead of it and extending slantingly in relation to the pins centerline.

The protection against torsion of the supporting pin within the insulator body of the cable connector is effected in that the portion of the supporting pin as inserted in the insulator body, is provided with one or more engaging noses or projecting portions distributed along the circumference thereof.

According to one advantageous type of embodiment of the supporting pin it is provided that the end of the supporting pin as mounted in the insulator body, is provided either with a conventional thread or with a sheet iron thread.

The depth of insertion of the supporting pin in the cable connector is restricted in that the supporting pin as provided with a thread, comprises a reinforced portion or thickening at the end of the thread.

For the purpose of fixing in position the tie strap or lacing tape serving the attachment of the individual wires of the bundle tothe supporting pin, the supporting pin is provided at its free end with two annular bulgings arranged at a spaced relation.

According to one example of an embodiment of the supporting pin it is proposed that the recess for strap or lace type strain relief as restricted by said annular bulgings, is constituted, for example, by a constriction.

The twisting or turning of the wire bundle can be reliably avoided in that the supporting pin, within the recess for the strap or lace type strain relief, has a preferably triangular cross section.

For simplifying the assembly of the supporting pin it is proposed that the free end surface thereof is crossslotted.

For permitting the supporting pin to be mounted also to threaded pins of the electrical connector it is proposed that a tapping hole he provided at the end of the supporting pin facing the mounting side.

With respect to some cases of practical application it may be of advantage that the shaft of the supporting pin has an elliptical cross section at the free end of which there are arranged two transverse straps extending parallel in relation to one another at a certain spaced relation.

A further embodiment of the supporting pin provides that the surfaces of the transverse straps respectively have a coneavely arranged shell-type arching.

Especially in the case of restricted space conditions, an advantageous further embodiment of the supporting pin of the electrical connector is seen in that between the mounting end and the recess for a strap or lace type strain relief on the supporting pin, the shaft is offset or arranged by being bent at an angle of preferably 90.

Another feature of the connector resides in the fact that the supporting pin is made either from metal or a plastics material.

For enabling the most favorable handling of the connector during assembly while mounting or placing in position the individual wires of the bundle, it is proposed that the supporting pin made from a plastics material, be provided within the recess for strap or lace type strain relief, with a tie strap or lacing tape comprising a row of holes molded thereto, and with a hook or patent fastener arranged on the shaft.

According to a further advantageous embodiment of the cable connector it is proposed that both the insulator body and the supporting pin consist of one piece.

The invention will now be described with reference to FIGS. 1 to 4 of the accompanying drawing, in which:

FIG. 1 shows the insulator body of an electrical connector equipped with contact elements, and the cable supporting pin as inserted therein, to which there are attached the wires of the contact elements, in a side view and partly in a sectional elevation,

FIG. 2 shows the cable supporting pin according to FIG. 1 as seen from the side,

FIG. 2A is a sectional view along 22 in FIG. 2,

FIG. 3 shows the cable supporting pin provided with an outside thread, in a side view,

FIG. 4 shows an example of an embodiment of the cable supporting pin provided with a tapping hole, partly in a sectional view as it would appear if seen from the side, and

FIG. 4A is an end view of FIG. 4 showing cross-slots.

Referring now to FIG. 1, reference numeral 1 indicates the insulator body of an electrical cable connector. This insulator body 1 contains a larger number of contact cavities 2 in each of which there is arranged a bayonet coupling sleeve 3 for detachably holding in position an inserted contact element 4 designed as a plug or socket. Holding in position is effected in that resilient bayonet tongues 5 engage behind the collar or shoulder portion 6 of the contact element 4.

As a strain relief for the wires 7 as connected to the contact elements 4 there is used a cable supporting pin 8 which, from the rearward facing surface of the connector is inserted into the contact cavity 2 of the insulator body 1 only containing a bayonet coupling sleeve 3. The portion of the cable supporting pin 8 entering into the insulator body 1 corresponds to the cross sectional dimensions of the contact cavity 2 which is preferably of a circular design. The end of the cable supporting pin 8 as inserted into the insulator body 1 is provided with a collar 9 which is constituted by a conical recess 10 arranged slantingly in relation to the centerline of the pin (see also FIG. 2). Upon insertion of the cable supporting pin 8 the tongues 5 of the bayonet coupling sleeve 3 serve to lock the collar 9 in position as is the case with the contact elements 4. For preventing the cable supporting pin 8 from turning inside the contact cavity 2 there are provided one or more noses or projecting members 1] distributed along the circumference of the pin shaft, with these noses pressing into the wall of the contact cavity 2 upon insertion of the supporting pin 8. These noses 11 are either flush with the rear side facing surface of the insulator body 1, or project only to a small extent.

At the end of the supporting pin 8 extending straight forward out of the insulator body 1 in the direction of the cable introduction side, there is arranged an annular bulging l2 and, at a certain spaced relation, a second such bulging 13. Between the

bulgings

12 and 13 there is provided the recess 14 for the strap of lace type strain relief 15, for holding in position the wires 7. The bulgings l2 and 13 thus serve to define the position of the tie strap or lacing tape 15 for surrounding and holding together the wires 7 as distributed around the cable supporting pin 8. For avoiding a turning of the thus attached wire bundle, the supporting pin 8 within the recess for strap or lace type strain relief 14 may, for example, have a triangular cross section as indicated most clearly in FIG. 2A.

Another example of embodiment relating to the cable supporting pin 8 is shown in FIG. 3. The end thereof intended for effecting the mounting in the insulator body 1, is provided either with a conventional thread, or with a so-called sheet iron thread 16 which may also be of the self-cutting type. In order to restrict the depth of insertion of the supporting pin 8, there is provided in this case a thickening or reinforced portion 17 acting as a limit stop.

A further example of embodiment of the supporting pin 8 is shown in FIG. 4. The recess for the strap or lace type strain relief 14 for holding in position the wires 7, is characterized by a constriction 18 on the supporting pin 8. Apart therefrom, a tapping hole 21 is provided at its end facing the mounting side. By this example, also outside the insulator body 1 to a threaded pin of the connector shell. In dependence upon the way of mounting the supporting pin 8, it may be appropriate for the free end surface 19 of the pin to be cross-slotted as indicated at 21 in FIG. 4A. A.

Although it is of advantage to let the supporting pin 8 project out of the center of the connector, a number of other arrangements are equally possible. The supporting pin 8 or a number of them can be mounted to any suitable point of the insulator body in the empty contact cavities 2 or in other recesses specially provided therefor. The mounting of the supporting pin 8 at the rim portion of the facing surface of the insulator body 1 may be desirable, for example, in cases where the wires 7 are led in from the side. With respect to such a case a bending 'of the supporting pin 8 is proposed between the recess for the strap or lace type strain relief 14 and the mounting end, with this bending preferably amounting to Provided that the recess 14 is sufficiently spaced from the contact sleeves 4, the shaft 20 of the supporting pin 8 arranged out of the center, may be bent towards the center without thus affecting the accessibility of the contact elements 4.

In dependence upon the density of contacts arranged in the insulator body 1 it is also advisable to design the supporting pin 8 in such a way that its shaft 20 has an elliptical cross section. At its free end there may then be provided two transverse straps extending parallel in relation to one another at a certain spaced relation, with the surfaces thereof respectively having a shelltype concave arching. In these archings there will then come to lie the wires 7 adjacent the shaft 20. The two (not shown) transverse straps, in turn, serve to fix the position of the tie strap or lacing tape 15.

Quite depending on the type of embodiment of the cable supporting pin 8, there may be used either metal or a plastics material. In the case of a supporting pin 8 made from a plastics material, it is possible to provide a recess 14 with a tie strap 15 molded thereto, and containing a row of holes suitable for effecting the mounting of a hook or patent fastener likewise molded to the supporting pin 8. With respect to cable connectors in which the wires or wire bundles are not exposed to any or only to slight lateral pull forces, the insulator body 1 and the cable supporting pin 8 may consist of one injection-model part.

What is claimed is:

l. A cable connector assembly comprising an insulator body, bayonet coupling sleeves secured in contact cavities in the insulator body to receive and hold contact elements forming terminals of a plurality of wires, a device for holding the wires and relieving strain on the terminals of the wires, the device consisting of a supporting pin having a first end inserted in a bayonet coupling sleeve in the contact cavity, and said pin including a recess near its second end into which the individual wires of the bundle are attachable by means of a tie strap.

2. A cable connector assembly according to claim 1, in which an end of said supporting pin as mounted in said insulator body is provided with a collar resulting from a conical recess ahead of it and extending slantingly in relation to said pins centerline.

3. A cable connector assembly according to claim 1, in which the supporting pin is provided with aprojecting portion distributed along the circumference thereof.

4. A cable connector assembly according to claim 1, in which said supporting pin is provided at its free end with two annular bulgings arranged at spaced relations to form the recess.

5. A cable connector assembly according to claim 1, in which said supporting pin, within said recess for the tie strap, has a triangular cross section.

6. A cable connector assembly according to claim 1, in which the second end of said supporting pin terminates in a surface which is cross-slotted.

7. A cable connector assembly according to claim 1, in which a tapping hole is provided at the first end of said supporting pin facing the mounting side.

Claims

1. A cable connector assembly comprising an insulator body, bayonet coupling sleeves secured in contact cavities in the insulator body to receive and hold contact elements forming terminals of a plurality of wires, a device for holding the wires and relieving strain on the terminals of thE wires, the device consisting of a supporting pin having a first end inserted in a bayonet coupling sleeve in the contact cavity, and said pin including a recess near its second end into which the individual wires of the bundle are attachable by means of a tie strap.

2. A cable connector assembly according to claim 1, in which an end of said supporting pin as mounted in said insulator body is provided with a collar resulting from a conical recess ahead of it and extending slantingly in relation to said pin''s centerline.

3. A cable connector assembly according to claim 1, in which the supporting pin is provided with a projecting portion distributed along the circumference thereof.