US1504655A - Attachment plug - Google Patents

Description

Aug 12, 1924; I 1,504,655

D. N. THOMPSON ATTACHMENT PLUG Filed Aug. 25 1919 i I Z wuautoz lPatented Aug... 12, 124.

DON N. THOMPSON, SCU'SE, NEW Y0.

ATTACHMENT PLUG.

Application filed August 25, 1919. Serial No. 319,645.

Toall whom it may concern Beit known that I, 'DoN N. Tnomrsou, a

' citizen of the United States', and resident/of Syracuse, in the county of Onondaga, State of New York, have invented certain new and useful Improvements in Attachment Plugs, of which the following is a specification.

Thepresent invention relates to electrical connectors and particularly to separable at tachm'ent plugs adapted to be used in connecting branch circuits, especially lamp circuits, with main supply lines or circuits.

The objects of the invention are to provide an article of 'this class which is light and strong, has aminimum number of parts thereby promoting ease of manufacture and assembly, in which the spring contacts are protected by the insulating base so that it is impossible for any one handling the plugs to bend and displace them or to establish connection between them through his fingers, thereby sustaining an electrical shock, and in which the openings in the plug which are provided for the insertion of the contact blades of the cap are automatically closed by the spring contacts to prevent the entrance of dirtinto the hollow interior.

The invention will be fully disclosed in the following description when taken in connection with the accompanying drawings in which:

Figure 1 is a longitudinal section of the plug, the cap being removed;

Iugure 2 is a top view of the plug base shown in Figure 1;

Figure 3 is a bottom view of the same, portions being removedj 7 Figure 4 is a dis-assembled view. of the entire structure.

The base 10, the cap 11, and the button 12 are of any customary insulating material, and the metallic parts of the. lug are of brass, copper, or other suitab e material. The base 10 is provided with recesses 13 and '14 on opposite sides of a central partition 15, and the recesses 13 and 14 communicate through openings 16 and 17 respectively with a central rectangular guide opening 18.

By means of a screw 19, having its head in a recess 20 in the central partition 15, the various metallic contacts and insulatingbutton 12 are attached to the base portion. The spring contact 21 has an o ning in its lower horizontal portion throng which the screw 19 passesand a nut 22 holds this contact in position with its upper portion contained within the recess 13. The upper portion of the spring 21 is in the shape of an inverted U, one leg of which lies close to and is parallel with the wall of partition 15, while the other leg is downwardly and outwardly inclined and has its end bearing a ainst the opposite wall of the recess 13. he upper rounded portion of the spring lies adjacent the opening 16 between the guide hole and the recess 13 and the springlis so designed that it normally tends to old the upper rounded portion thereof in the opening to close the same, and its outer end by continually pressing on the wall of the recess tends 7 0 to force the remainder of the spring toward the partition. The screw 19 has at its lower end a nut 22 which cooperates with the screw in securing the button 12 and the shell contact 23 to the base and which also serves as a center contact for the plug when the latter is screwed into a socket.

The shell contact 23 is of the usual construction and is clamped by means of the screw 19 and nut 22 between the insulating button 12 and the base 10. To the upper en of the shell contact 23 is secured the spring contact 24 which is constructed exactly in the same manner as the spring contact 21 and designed to operate in'the same way to normally close the opening 17. The cap 11 is of the usual construction and has secured thereto downwardly projecting contact blades 2/1 and 25 which are adapted to be inserted through openings 16 and 17 into the recesses 13 and 14: and to establish contact with the spring contacts therein.

In inserting the contact blades into the base the ends of the blades after passing through the openings 16 and 17 respectively strike the rounded portions of spring contacts 21 and 24 and after forcing them radially outward a sufficient distance pass downwardl between the spring contacts and the insulating partition 15.

When the cap is seated the notches 26 in the contact blades are engaged by the lugs 27 on the contact springs and the cap is locked in position against accidental movement.

While I have shown the contact springs 21 and 24 as hearing against both the outer walls of the recesses and the walls of the partition, it will be apparent that they may be otherwise arranged and still normally minate in the bottom of the close the openings 16,17, hence I do notlimit" said button upwardly through said partition myself to the exact'form of the device as illustrated. 7

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

1. A separable attachment plug comprising in combination, an insulating body having two spaced recesses terminating below the upper surface and separated by a central partition and a single guide hole slightly overlapping at its end a'portion of the top of said recesses and extending to a plane below their upper ends, thus communicating with both of said recesses, a contact in each of said recesses hearing against said partition up to its top and to the bottom of said guide hole and there bent outward from said partition.

2. A separable attachment plug comprising in combination, an insulating body having two spaced recesses therein at equal distances from its axis and a single centrally located guide hole overlapping a portion of said recesses slightly at its ends and extending below their upper ends thus communicating with both of said recesses, a spring contact in each of said recesses extending outwardly and upwardly from the line wherethe adjacent walls of the recesses teride hole to the line where the top walls 0 the recesses terminate in the end walls of the guide hole thus normally closing the entrance openings leading into the recesses.

3. A separable attachment plug comprising in combination a substantially cylindrical insulation body haying an elongated rectangular guide opening in the top thereof and a pairvof contact recesses open at the bottom, separated by a partition and having lateral and partial longitudinal communication with said guide opening, an insulation button, a threaded contact shell fitting between and abutting at the ends against the insulation body and the button, a central contact member, a single member holdin all of said parts together and a pair 0 spring contacts in said r'ecessesengaging said partition along the upper end thereof and having curved ends adapted to normally close the openings between said contact recesses and said guide opening for thepurpose set forth.

4. A separable attachment plug comprising in combination an insulating bod portion having two spaced recesses t erein separated-by a partition and a single guide hole communicatin with both of said recesses through openings on opposite sides of said partition, a shell contact abutting at its upper end said body around the open ends of said recesses, an insulating button abutting the lower end of said shell, a connecting member extending centrally from to a point below the bottom of said guide hole and two spring contacts one of which is connected at its lower end to said connecting member below the body and extends upwardly therefrom in one recess to its opening and the other of which is fixed at its lower end to said contact shell and extends upwardly in the other recess to its opening.

5. A separable attachment plug comprising in combination a body of insulating material having an elongated rectangular guide opening arranged centrally in its upper end and extending a short distance downward, and having two similar separated lon itudinal contact recesses of the same widt as said rectangular guide opening extending at their-facing sides under the ends of said opening a distance sli htly more than the thickness of contact blades and,extending a material distance outwardly beyond the ends of said opening and terminating at their upper ends slightly above the bottom of said guide opening whereby the lane of the entrance connections or openlngs between said uide opening and recesses extends outwardly and upwardly at an angle, and spring contacts in said recesses extending substantially across them and curved outwardly at their upper ends to lie in substantially the plane of said entrance connection and normally close it.

6. An attachment plug comprising in combination an insulating body having two recesses therein on opposite sides extending upwardly from the lower end to a point near the top and an elongated rectangular guide opening centrally arranged in the to with its ends slightly intersecting the a jaeent edges of said recesses and extending slightly below their upper ends thus joining them and forming communicating openings, a

shell contact fitting at its upper end said I body around the open ends 0 said recesses, a button of insulating material fitting the lower end of said shell, a centrally arranged screw extending downwardly through said body with its head engaging said body below the bottom of said guide opening and centrally through said shell and button, and provided at its lower end with a nut for clamping said body shell and nut together, two spring contacts, one of which is connected at its lower end to said screw below the body, extends upwardly in'one recess, and at lts upper end is bent outwardly at the opening into the guide opening, and the other of which is connected at its lower end to the upper end of the shell extending upwardly in the other recess and at its upper end bent outwardly at the opening into the guide opening.

In testimony whereof I aflix in signature,

DON N. THOKIPSON.

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