US1782447A

US1782447A - Method of forming electrical terminal members

Info

Publication number: US1782447A
Application number: US202277A
Authority: US
Inventors: Scrantom De Hart Gridley
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1927-06-29
Filing date: 1927-06-29
Publication date: 1930-11-25
Anticipated expiration: 1947-11-25

Description

Now-25, 1930. DE HART G. SCRANTOM 1,782,447

METHOD OF FORMING ELECTRICAL TERMINAL MEMBERS Filed June 29. 1927 Patented Nov. 25, 1930 UNITED STATES PATENT OFFICE DE HART GRIDLEY SCRAN TOM, OF MAPLEWOOD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF METHOD OF FORMING ELECTRICAL TERMINAL MEMBERS Application filed June 29,

This invention relates to a method of form ing electrical terminal'members, and more particularly to a method of forming cast terminal clips on electrical conductors.

An object of the invention is to providea simple, eflicient and inexpensive method of producing a strong and durable terminal clip on a metallic strand.

In accordance with'one embodiment, the invention contemplates the provision of a method for integrally securing a terminal member to a metallic strand consisting in casting the terminal member and attaching it to the strand simultaneously. S ecifically, the invention resides in a method For casting terminal clips and affixing them to insulated electrical conductors, in which the molten metal is forced against the endof the insulat ed conductor in such a manner as to remove the insulating material from the tip of the conductor while the metallic strand 'or strands of the conductor which are more rigid and which do not flare to the same extent become firmly embedded in and form a good electrical connection with the terminal mem- It is believed that a complete understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawing illustrating terminal cli s produced by the method and one type of mold or die which may be used in practicing the method, and in which Fig. 1 represents a fragmentary, plan View of adie in which the terminal clips may be cast;

Fig. 2 is a sectional view 22 of Fig. 1, and

Fig. 3 is an enlarged sectional view showing a stranded conductor embedded in a terminal clip.

Referring to the drawing in which similar reference characters designate the same parts in the several views, a mold or die 7 of any usual type employed in die casting, is'shown taken on the line consisting of an upper section 8 and a lower section 9. The die may be made of any metal suitable for die or other pressure casting such as steel and each section is provided with re- 1927. Serial No. 202,277.

cesses which cooperate with recesses in an opposing section to form cavities 13 into which the terminal members are cast. Between the cavities of each pair a small compression chamber 12 of the usual type is located which connects with the cavities by means of small depressions 16 in the lower die section a few thousandths of an inch deep for the purpose of allowing the air to escape from the cavities as they are being filled with molten metal. The cavities 13 are all interconnected by means of a channel 14 in the lower die member which leads to an opening 15 through which molten material, suitable for die casting, such as zinc-magnesium alloy or aluminum and adapted to produce terminals having the requisite physical and electrical characteristics is forced into the cavities. The

sections

8 and 9 are also provided with cooperating grooves forming openings 10 into which the conductors 11 which are to be provided with terminal members may be inserted into the cavities 13.

In practicing the method, the insulated conductors to be provided with terminal members, which may comprise a plurality of twisted cotton or other textile cores spirally served with electrically conducting tinsel ribbon and covered with braided textile sheaths are placed, without the removal of the insulation therefrom or other preparation, in the grooves in the lower section 8 of the die so as to extend into the cavities 13 the desired distance and the upper section 9 is placed in position firmly clamping the portions of the conductors in the openings 10. The molten metal is then forced under pressure into the opening 15 as is well understood in the art of die casting, from where it follows the channel 14 leading to the cavities l3, filling them with metal. When the molten metal is forced against the fiat end of the insulated conductor, the ends of the strands of the textile insulating material will unravel and on account of the flexibility of the strands the in-' sulating material will be flared and moved to a position in which it will become completely embeddedin the material of the terminal. The metallic strands of the conductor are more rigid and will therefore outwardly not be flared as much as the insulation so that the metal of the terminal clip is cast directly around the strands of the conductor and becomes molecularly integral with the conductor, producing a good joint from a mechanical as well as an electrical standpoint. After the terminal clips have cooled suflioientl they are removed from the die and trimmed from the metal in the channel completing the die casting operation. j It will be understood that the embodiment ofthe invention herein described and illustrated is merely a convenient and useful form of the invention, which is capable of many other modifications without departing from the spirit and scope of the invention.

\Vhat is claimed is: 1. ,A method of making a terminal member for an insulated conductor, which comprises forcing a molten metal longitudinally against the end of the insulated conductor to remove the insulating material therefrom, and formi-ng the metal into a terminal member contacting with the conductor where the insulation is removed and overlapping a portion of the insulation.

2; A method of making a terminal clip for a conductor having a stranded textile insus lation, which comprises forcing a molten 00 metal longitudinally against the end of the conductor and the insulation so as to flare the insulation, and forming the terminal clip over the conductor and the flared insulation.

3. The method of providing a terminal clip on an insulated electrical conductor having flexible strands, which consists in forcing I molten metal longitudinally against the end of the conductor, causing the-metal to flare the insulation and the flexible strands, and 40 cooling the metal While confining it in the shape of a terminal clip. In witness whereof, I hereunto subscribe my name this 14th day of June, A. D. 1927. DE HART GRIDLEY SGRANTOM.