US2149137A - Terminal connector - Google Patents

Description

Feb. 28, 1939.

F. G. GARDNER TERMINAL CONNECTOR Original Filed June l2, 1935 ATTORNEY iti Patented Feb. 28, 1939 TERMINAL CGNNECTOR Frank G. Gardner, Maplewood, N. J., assignor to Breeze Corporationc, Inc., Newark, N. J., a corporation o! New Jersey Original application June 12, 1935, Serial No.

26,096. Divided and this application June 10, 1937, Serial No. 147,457

1 Claim.

This invention relates to a terminal connector, and particularly a connector for making contact between an ignition conductor and a. spark plug. This application is a division of application, Serial No. 26,096, filed June 12, 1935, now Patent 2,083,916, issued June 1 5, 1937.

Where radio receiving apparatus is used in proximity to an internal combustion engine it is desirable to shield the spark plugsof the engine to prevent interference with radio reception. It is common practice to enclose the exposed portions of a spark plug in a radio shield. The radio shield normally encloses a portion of the ignition cable adjacent the spark plug, and the remainder of the cable is shielded by means of a flexible metallic conduit or similar structure. Under these conditions the heat generated by the use of the spark plug in service cannot be readily dissipated. The excessive heat is transmitted to the insulation of the ignition cable and tends to cause a rapid deterioration of the insulation of the ignition cable.

The heat causes a charring of the insulation of the ignition conductor and eventually` a breakdown of the insulation, which is undesirable. The effect of the heat is most noticeable at the end of the ignition conductor immediately adjacent the spark plug. It has been the practice to insert the insulation conductor into a shielding means and use a pointed contact element to pierce the insulation and making contact with the ignition conductor. This has permitted a direct transfer of heat from the upper end of the spark plug to the kinsulation of the ignition conductor with the deleterious eects above pointed out.

Therefore, vthe broad object of the present invention is to provide a connection in which the electrical contact may be made with the ignition lconductor without damage to the insulation surrounding the conductor. A specic object of the invention is to provide an insulated ignition conductor in which the conductor will extend past the insulation and on which a helical member may be supported to insure a proper electrical connection.

The invention consists of the constructionf the invention, in which drawing similar reference characters designate corresponding parts, and in which:

Figure 1 is a vertical section through a shield- (ou. 12e-res) ing cap, the spark plug, ignition cable and contact means being shown in elevation; and,

Figure 2 is a fragmentary detail in vertical section, taken approximately on line 2--2 of Figure 1, looking in the direction indicated by the arrows.

Referring to the drawing, the spark plug comprises a shell 6 having a threaded portion 'i to enter the cylinder head of an engine. The lower portion of the spark plug is provided with a curved base 8 and a plurality of slots 9 to provide a plurality of sparking areas. A washer I3 is provided to make a seal between the spark plug and engine cylinder. The upper dielectric portion of the spark plug 24 is provided with a metallic cap 25 formed with a recess 26 to receive a contact hereinafter described. 'I'he parts of the spark plug are held in the shell 6 by means of a cap 30 to which is secured a radio shielding cap 33 by means of aV coupling nut 35 having an inturned portion 35. The structure of the spark plug per se forms no part of the present inven-s tion.

The cap 33 is removable from the sparkplug upon rotation of the coupling nut 35. The cap 33 is provided with a dielectric lining 31 having a thickness sufficient to effectivelyy insulate the terminal 25 and the contact means, hereinafter described from the cap 33. The upper portion of the lining 3l is formed with a bore 38 to receive a conductor with its insulation. In order to prevent the insulation of the conductor from being vulcanized to the walls of the bore 38 by reason of the high temperatures encountered, the walls oi'` the bore 38 are formed with ribs 39 which space the insulation of the conductor from the walls and provide a passage for the circulation of air.

Carried by the lining 3l is a threaded bushing 40 in which is threaded a contact screw 4| to the lower end of which is yconnected a spring 42 adapted to make contact with the terminal 25 of the spark plug. The upper end of the screw 4l is provided with a point 43 adapted to make contact with the conductor.

A conductor 44 surrounded'by insulation 45 is provided to supply current to the spark plug. In the past, it has been the practice to extend the insulation 45 to the left hand end of the bore 38 and the point 43 of the screw 4l was used to pierce the insulation 45 to make contact with the conductor 44. This practice causes burning of the insulation 45, which is undesirable. In order to avoid this condition the conductor 44 is extended to the end of the bore 38 but the insulation thereof 45 is removed for an appreciable distance, as shown in Figure 1. A coil spring 46 is connected to the conductor 44 and surrounds the conductor. The spring 46 may be soldered to the extreme end of the -conductor 44 and the right hand end of the spring 46, as shown in Figure 1, will abut the insulation 45 of the conductor 44.

As shown in Figure 1, the screw 4i will separate the turns of the spring 66 to make a contact. As shown in Figure 2, the point 43 of the screw il will force the conductor @il to one side and thereby make contact not only with the spring 46 but also with the conductor 44.

At the point where the conductor 46 with its insulation 45 leaves the cap 33, a conical packing 41 provided with a copper or other metallic reinforcing means i8 is disposed. The packing 4'!! may be of the type shown in co-pending application, Serial No. 731,833, led June 22, 1934, now Patent No. 2,087,920, July 27, 1937 and not only provides a waterproof joint, but the metallic portion 48 serves to improve the electrical contact between the cap 33 and a radio shielding conduit 49 which surrounds the conductor 44 with its insulation 45. The conduit 49 is provided on its end with a ferrule 50 formed with a ange i, and a coupling nut 52 serves to hold 'the conduit 49 against the cap 33 by reason of engagement with threads 53 formed on the cap 33. The pressure of the ferrule 50 against the packing 41 has a tendency to force the packing 4l inwardly against the insulation 45, thereby holding the conductor 44 rmly in place and removing any strain from the end of the conductor,

which eliminates the possibility of breakage of the conductor 44 at the point of contact with the screw 4l.

The general structure of the shielding cap and contact means may be the same as shown in copending applications Serial No. 481,766, led September 13, 1930, and Serial No. 657,166, filed February 17, 1933, now Patent No. 2,080,827, May 18, 1937. 'I'he structure of the conduit may be the same as shown in co-pending application Serial No. 657,167, led February 17, 1933, now Patent No. 2,028,793, January 28, 1936.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent is:

In combination with a sparkplug, a radio shielding cap therefor and a contact means carried by the cap to make contact between the electrode of the sparkplug and a supply cable, a supply cable comprising a stranded conductor, a dielectric covering on the conductor termina-ting an appreciable distance from the end thereof, a coil spring having its outer end permanently secured to the outer end of the conductor and its inner end abutting the insulation on the conductor, said spring surrounding the uninsulated portion of the conductor and being spaced therefrom, the turns of the coil spring being separated from one another so that the contact means carried by the cap enters the coil spring to make contact therewith and with the stranded conductor.

FRANK G. GARDNER.

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