US1753627A - Cable terminal - Google Patents

Description

April 8, 1930. w. E. scHWAR-MANN EIT Al. 1,753,627

' CABLE wrizmvrIhIALl Filed July 29,

INVENTOR WOLFGANG E. SCHWARZMANN ADOLFH ROSNER ATTORNEY Patented Apr. s, 1930 UNITED STATES PATENT oFFicE WOLFGANG E. SCHWARZMANN, OF LONGMEADOW, ANDI'ADOLPH ROSNER, 0F SPRING- FIELD; MASSACHUSETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE ELECTRIC AUTO-LITE COMPANY, A- CORPORATION OF OHIO CABLE TERMINAL Application led July 29, 1921. Serial No. 488,304.

The present invention relates to connectors for electrical cables, such as those used in ignition systems for internal combustion engines.

I-Ieretofore, the plug member of a plug and socket type of cable connector, has been made with inwardly projecting pieces that extended transversely into the insulating covering of the cable. It was necessary, in such member, to manually attach it to the end of the cable by iirst spreading the side portions of the member sufficiently to permit the insertion of the cable and then to forcibly cause the lateral extensions to enter the insulation. When shipping instruments or apparatus using such members, the same, if placed in their respective sockets, had to be withdrawn from such socketsat the time of attaching these members to the cable ends and accordingly, could not be attached to the cable ends while in such sockets.

In accordance with this part of the invention, we form the plug member with a plurality ofinwardly projecting and downwardly extending prongs which` permit the ready insertion ofthe end of the cable in the plug member, but becomes fixed to the cable when it is moved in the opposite direction, thus preventing the withdrawal of the cable from the plug member, the prongs digging into the cable covering for such purpose. It will be thus apparent that when the cable is withdrawn from the socket member,'the plug member will be withdrawn therefrom as a unitary part of the cable. In order to give stiEness to the prongs and to reduce the amount of material required for a plug member of a given length, the prongs are preferably located intermediate the ends of the plug member, while the latter may also have at its lower end an inwardly extending` projection adapted ,to enter into the electrically conductive part of the cable when the latter is inserted into the plug member. v

Referring more particularly to the accompanying drawing, upon which are shown a few embodiments of the invention, in application, as for example, to a distributor head and spark plugs of an ignition system for internal combustion engines:

Fig. 1 is a vertical sectional view of a' distributor head showing the connectors in connected position; Fig. 2 is a side view in elevation of the plug portion of the connector, with the cableend in place therein; Fig. 3 is a longitudinal sectional View of the same taken on line 3 3 of Fig. 5; Fig. 4 is a developed plan view 0f the plug member; Fig. 5 is a bottom plan view of the plug member with the cable end in place; Fig. 6 is a transverse sectional view taken on line 6 6 of Fig. 3; Fig. 7 is a longitudinal vsectional view of the plug member per se.

' head 1, the lower terminals being formed integral with the socket members 6 embedded in the posts or towers 7 from which lead the high tension leads 8 to the respective spark plugs in the engine cylinders. In the center of the head 1 is provided a central tower or post 9 having a metal insert 10 recessed at its lower end to receive a contact brush member 11 cooperative with the inner end of the brush 3 in a knownmanner, and provided at its other end with the socket member 12, similar to socket 5, for receiving the end of a high tension lead or cable 13 extending to the secondary winding of an induction coil or magneto armature; l

The connector comprises, in general, a socket member, such as the member 6, and a plug'member 14. The latter is constructed from a sheet metal punching, shown in developed plan form in Fig. 4 of the drawing. This punching or blank comprises, in general, a border portion 15 having a plurality of downwardly extending finger portions 16 and 17 arranged in spaced relation, two of these finger portions being connectedtogether by a transverse connecting member 18, thus rigidly maintaining the relation ofthe adjacent or connected fingers 17. Alternating with the fingers 16 and 17 are also provided downwardly extending sharpened portions or prongs 19 which are bent inwardly and extend downwardly, as viewed in Figs. 1, 2, 3, 4 and 7 of the drawing, for a purpose hereinafter more fully described. The connecting portion 18 isalso provided with a downwardly extending portion 20 which may be suitably sharpened or pointed and bent to enter into the electrically conductive part of the cable, as will hereinafter more fully appear. It will be observed that the portion 20 is located between and adjacent the lingers 17 and is sheared or slitted on the lines 21, in order that the member 20 may be readily shaped into the'form shown in Fig. 3 of the drawing, when the punching or blank is rolled and shaped for connection with the end of the cable. The fingers are also preferably provided with widened portions 22, such that When bent on the lines 23, as shown in Fig. 4, the end portions 24 will extend inwardly in a transverse fashion at the end ofthe plug member, as is clearly shown in Figs. 2, 3, 5 and 7 of the drawing, and with the widened portions 22 located near each other, so that the same may encase or surround the lower end of the cable, particularly the cover thereon, so as to prevent the upward projection of the frayed ends of the braided threads of the cable sheathing.

The punching or blank is rolled into the form of a cylinder so that the ends 25 and 26 thereof will be located adjacent each other and the ends 24 bent inwardly as well as the end portion 20, the latter being bent about the lines 27 and 28, as shown in Fig. 4 of the drawing, thus forming a sort of U-shaped member or hook with the point 29 thereof eX- tending inwardly and upwardly within the interior of the plug member. With the member in the form above described, it will be noted that the prongs 19 extend inwardly and downwardly, so that when the end of the cable is inserted or forced into the plug member, the insulating covering of the cable will be permitted to pass by the ends of the prongs 19, but any tendency towithdraw the cable will cause the prongs 19 to be forced inwardly into the insulating cover, thus preventing the cable from becoming detached from the plug member, Athe latter thus becoming fixed to and forming a unitary part of the end of the cable. It will be also observed that when the end of the cable is inserted in the plug member, the point 29 of the member 20 '5 is located centrally, so that it will be forced inwardly into or among the wires of a conducting portion of the cable.l The member 20 lunay be caused to bend as the end of the cable is forced onto or over the point 29, and therefore, for the purpose of preventing total deformation of the member 20, the end portions 30 of the fingers 17 are so bent and cut that they will over-lap the member 20 at the lower end of the plug shell, as is clearly shown in Figs. 3 and 5 of the drawing. As

the member 20 is forced downwardly, it will contact with the oven-lapping portions 31 of the portions 30, such over-lapping portions accordin 'ly acting as an abutment means for the mem er 20 tofprevent further bending thereof, as the end of -the cable is forced into the plug member. A slight backward pull of the cable will cause the prongs to dig in rmlyinto the insulating covering of the cable, and also permit the member 2O to return to normal shape, such as is shown in Fig. 3 of the drawing.

The spring fingers 16 and 17 are also further outwardly bent to form groove engaging positions 32, which are adapted, when the plug member is inserted in the socket, to snap into or engage in an internal annular groove 33 formed in the socket member 5. iThe fingers 16 and 17 will radially flex inwardly when the plug member is inserted in the socket member until the bent portions 32 arrive opposite the groove 33 and resiliently snap thereinto, such bent portions acting to normally hold or maintain the plug member and the attached cable within said socket, yet

permitting the unitary detachment thereof by a strong manual pull of the cable.

It will beobserved that the type of connector above described is not limited to use in any particular device, such as a distributor head, but may also be connected to various other devices, such as spark plugs and the.

like.

The end of the cable is merely cut without further trimming or other preparation for connection to the connector. It is merely necessary to transversely cut the cable and then insert the cut. end thereof into the plug member. In the manufacture of electrical equipment, such as that used in ignition systems, it is customary to ship -the same with the connector members, particularly the part to be eventually attached to the cable, tied to the instrument with a piece of wire or cord..

When installing the same, the connector member must then be attached to the cable. This inconvenience is avoided by the present invention by insertin the plug member into the sockets of the dlstribu'tor, at the time of shipment, and when the apparat-us is later installed, it is merely necessary to cut a cable to suitable length and insert the cut end thereof into the plug member while it is still in its socket. Wardly into the plug member, it will pass by the prongs 19 and engage with the point 29 so as to establish electrical connection between the latter and the electrical conductive part of An opposite pull upon the cable As the end of the cable is forced inllli part thereof, the spring fingers 16 and 17 readily exing for t at purpose.

We claim: Y 1. A socket fitting plug adapted to be at- 5 tached to the end of an electric cable, comprising a tubular body portion having an open end adapted t receive the end of the ca le v the sides of said body portion being adapted to snugly fit the sides of the cable; a prong integral with said tubular body portion, forming in part the closure for the opposite end thereof and adapted to enter the conducting portion of said cable as said cable is inserted into said body portion; means to reinforce said prong against distortion when said cable is so inserted; and means integral with the sides of said body portion adapted to close in upon said cable to prevent the removal of said cable when such removal is attempted.

2. An electric cable connector; a plug member adapted to t in o a socket member the plu member made o sheet material and adapte to be attached to the end of an electric cable comprising: a tubular portion; a

plurality of finger portions extending therefrom in spaced relation; an extending prong connecting two of said finger portions adapted to be bent forming part of the closure or the end of the cable and arranged to enter the conducting portion of said cable when said cable is inserted; a plurality of/inwardly rojecting prongs alternately extending om said tubular portion with respect to said ngers and arranged to permit the insertion of the end of said cable and become fixed thereto.

' 3. An electric cable connector; a plug member adapted to fit into a socket member, the plug member made of sheet material and 4o' adapted to be attached to the end of an electric cable comprising: atubularvportion; a

pluralit of spaced fingers; a lurality -of cabledholldin prongs between sai -fingers, the

finger ends eing enlarged-transversely and tapered to a point; a bridge connecting two ngers and a piercing (point extending from said bridge and adapte to enter the conducting portion of the cable when said cable is inserted in said plug. Y

In testimony whereof I aix my siture.

ADOLPH ROS R.

In testimony whereof I affix m signature.

WOLFGANG E. SCHW

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