US2997411A

US2997411A - Closed end connector

Info

Publication number: US2997411A
Application number: US613545A
Authority: US
Inventors: Harold O Woolley
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1956-10-02
Filing date: 1956-10-02
Publication date: 1961-08-22
Anticipated expiration: 1978-08-22

Description

Al1g 22, 1961 H. o. wooLLEY 2,997,411

CLOSED END CONNECTOR Filed OCT.. 2, 1956 2 Sheets-Sheet 1 INVENTOR.' V/vaa aafz BY WIM W A TTORNE YS Aug. 22, 1961 H. o. wooLLEY 2,997,411

CLOSED END CONNECTOR Filed oct. 2, 195e 2 sheets-sheet 2 IN VEN TOR. jwoz 0 j lfooufy BY United States Paty wff 2,997,411 4CLOSED END CONNECTUR Harold 0. Woolley, Hershey, Pa., assignor yto Incorporated Filed Oct. 2, 1956, Ser. No. 613,545 l5 Claims.` (Cl. 1154-223) This invention relates to insulated electrical connectors. of the type adapted for pressure application on a wire to make an electrical connection therewith. More particularly this invention relates to insulated closed-end connectors and a method `for closing the insulation about one end thereof and constitutes a continuation-impart of application No. 224,370, filed May 3, 1951, now Patent No. 2,803,695. H.

In connectors of the type adapted to permanently join two or more wires or the like, it is sometimes desir-able to insulate the connector before pressure-forming. In connectors wherethe wires to be connected enter the same end of the terminal, it is also desirable to seal the insulation over the opposite end.

Heretofore When making insulated closed-end connectors for pressure application, it lhas been the practice to seal the end of the tough malleable plastic sleeve after application onto the connector ferrule -by heating and spinning the sleeve against a tool so as to work Asome ofthe material of the sleeve over the end.

It is a primary object of the,| present invention to make a closed-end insulated connector that can be moreeasily and quickly formed, is certainly and perfectly sealed, and the closed end is reinforced against rupture.

It is another object to make an end cllosure that will not expand the circumference of the insulating sleeve.

It 'is a still further object to provide an endv closure which seals and reinforces the insulating sleeve.

Another object is to provide for a long leakage path through the closedV endy of the insulation in the event f any hidden defect in the closure; so that the insulation will be fully effective notwithstanding such defect.

A further object of this invention is to provide a method of closing the end of a connector by coniining the plastic sleeve during the closing operation so that the plastic does not extrude beyond the outside diameter of the connector.

Other objects and attainments of the present invention will [become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes `of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1 is a perspective view of the connector according to the present invention;

FIGURE 2 is a section on line 2-2 of FIGURE 1;

FIGURE 3 is an end view of the closing jaws and a sleeve to be closed;

FIGURE 4 is a view similar to FIGURE 3 showing the jaws in full compressing position;

FIGURE 5 is a side IView of the die used in FIGURES 3 and 4 taken along the line 5--5 of FIGURE 4;

FIGURE 6 is a perspective view `of a connector similar to FIGURE l after crimping; and

FIGURE 7 is a perspective view of a further embodiment of the present invention showing a fragmentary view of the closure dies.

2,997,411 Patented Aug. 22, 1961 FIGURES 8-10 are Views of closure `dies embodying and illustrating the confining feature.

Referring to FIGURES 1 and 2, a ferrule portion 10 is surrounded by an insulating sleeve 12 which extends substantially beyond both ends of the ferrule portion-.- one end 14 of which forms the mouth to receive, ernybrace and support the insulation of the wires to be crimped (FIGURE 6) and the other end to be closed over and seal the opposite end of the connector. If desired, the metal ferrule 10 may lne located on the outside of the plastic instead of inside; or it may be omitted altogether if the plastic is suliciently rigid and malleable'.

The insulating sleeve 12 is a tough, malleable, thermoplastic capable at room temperature of transmitting pressure sufficient to cold flow the rnetal of the ferrule without destroying the insulating properties of the plastic, and also capable of being formed itself by such pressure. Among such plastics, for example, are the slightly plasticized vinyl chlorides oftenreferred to as rigid vinyl chloride plastics, which will ordinarily have a few percent of vinyl acetate as plasticizer-'copolymen molding nylon and vinylidene chloride (sold commercially as Saran).

Referring to FIGURE 3, four die jaws 16 are seen to be.l

radially disposed at substantially equal intervals about the axis 18 ofthe ferrule when positioned for closing of its end. Each jaw `face has an included angle of about a lower beveled face 22, as shown in FIGURE 5, and corners 17 rounded to a small radius.

In one form of the invention the assembled ferrule,

after assembly on the sleeve, is gently heated until the sleeve is rendered capable of molding without substantial elastic memory and is then positioned so the heated end is substantially centered on the axis 18 and extends only a short distance into the space between the surfaces 24 of the vend-closing dies (FIGURE 3). The jaws are then closed radially toward axis 18 driving adjacent portions of the sleeve circumference together until the opposing faces of the adjacent portions meet and cohere to seal completely the end of the connector (FIGURE 4). Since the plastic was heated and softened, it may be easily shaped to the form and thickness desired and adjacent portions will readily cohere. I'he dies are then withdrawn leaving four radially disposed ns 26, as the remnants of the folds first formed, closing the end of the insulating sleeve with the material driven inward from the sleeve by the dies 16 and extruded from ybetween the surfaces 24 as the dies are closed together.

Alternatively, the assembled ferrule and sleeve is centered between the die jaws which in their expanded or rest position are maintained at an elevated temperature, of about 400 F., for example by gas flames (not shown). The heated dies are forced inwardly against the cold in sulating sleeve, which is softened by the heat of the dies, until adjacent portions of the circumference are folded and flowed together to close the end of the insulating sleeve. When the dies are again withdrawn, the four radial ns are left closing the sleeve.

The wires to be connected are inserted through the open end 14 into the ferrule 10 and the connector is crimped, forging the ferrule portion onto the wires in any of the several Ways well known to the art, while the end of the plastic sleeve overlying the wire insulation may be crimped also to tightly embrace and support the wire and, if required, to seal the connection.

Thus a simple, positive and tightly sealed end closure for a connector can be easily formed.

Of course, the assembled ferrule and sleeve may be inserted into a multi-die assembly, (similar to the four die assembly described above) wherein the total sum of the included angles of the die jaws equal 360 degrees, resulting in a multi-iin end closure.

Others are,

only two indents of approximately' 180, the flattening' of the sleeve tends to give an end closure which has a greater diameter than the sleeve itself. This maybe corrected by using dies which surround the end while it is being flattened. This confines the extrusion to a direction parallel to the axis, as shown in FIGURES 8-10. An illustrative embodiment of particular dies employed in forming a confined closure as shown in FIGURE 8 and includes a female die 1Gb which coniines the softened end of the connector in a die nest 1817, composed of a concave surface. An opposing male die 1Gb is forced horizontally toward the female die to close the end of connector Within they `die `faces, which confines the extrusion of the plastic. Also the male and female dies may be made in the form of mirror images as shown in FIGURES 9 and l0 which cooperate to close the end of the connector while confining, the extrusion of the plastic. Each of these dies, 16C, 16C', is similar to die 16b od FIGURE 8. However, they are ione-half as deep, so that each die acts as a confining 4member during the sealing process.

While there are given above certain specilic examples of this invention and its application in practical use and also certain modications and alternatives, it should be understood that these are not intended to be exhaustive or to be limiting of the invention. On the contrary,y these illustrations and the explanations herein are given in order to acquaint others skilled in the art with this invention and the principles thereof and a suitable manner of its application in practical use, so that others skilled in the art maybe enabled to modify the invention and to adapt it and apply it in numerous forms, each as may be best suited tothe requirement of a particular use.

I claim:

1. In the art of making electrical connectors having an insulating sleeve closed at one end, the steps of, heating at least one end of said plastic and indenting the plastic in successive segments of the circumference of said end of the sleeve, and sealing said. end of said sleeve by pressing together adjacent areas of ladjacent segments of said sleeve while maintaining the diameter of the sleeve constant until a substantial portion of the material thereof is extruded axially.

2. The method of making electrical connectors of the closed-end type which comprises forming a cylindrical, highly conductive ferrule portion, surrounding said ferrnle with a tough malleable plastic sleeve, conning said sleeve against radial extrusion, closing one end of said sleeve byl applying a plurality of heated die jaws about the `circumference of said sleeve, and forcing them swbstantially together at approximately thev center of said sleeve.

3. In the art of making electrical connectors` of the closed-endv type the method of closing one end of a cylindrical insulating sleeve which comprises radially dispos ingv at substantially equal intervals about the perimeter of' one end of" said sleeve four jaws, heating said jaws, and forcing said jaws inwardly until adjacent portions of said perimeter are'iolded together and sealed. y

4. In the art of making insulated electrical connectors including the steps of: (1) forming a length off deformable plastic tubing, (2) positioning a metal ferr-ille centrally within the tubing, (3) closing and sealing one end of the tubing While simultaneously confining the tubing' against extrusion.

5. The method as set forth in claim 4- wherein sealing is eiect/ed by heating the plastic to soften it and then denn-mingthe perimeter inwardly by a pluralityv of radiallyy operating jaws.

References Cited in the tile of this patent UNITED STATES PATENTS 2,077,653 Westin Apr. 20, 1937 2,265,359 Neumann Dec. 9, 1941 2,288,918 Parker July 7, 1942 2,740,101 Betts Mar. 27, 1956

Claims

1. IN THE ART OF MAKING ELECTRICAL CONNECTORS HAVING AN INSULATING SLEEVE CLOSED AT ONE END, THE STEPS OF, HEATING AT LEAST ONE END OF SAID PLASTIC AND INDENTING THE PLASTIC IN SUCCESSIVE SEGMENTS OF THE CIRCUMFERENCE OF SAID END OF THE SLEEVE, AND SEALING SAID END OF SAID SLEEVE BY PRESSING TOGETHER ADJACENT AREAS OF ADJACENT SEGMENTS OF SAID SLEEVE WHILE MAINTAINING THE DIAMETER OF THE SLEEVE CONSTANT UNTIL A SUBSTANTIAL PORTION OF THE MATERIAL THEREOF IS EXTRUDED AXIALLY.