US2590354A - Detachable latched electrical plug and socket connection - Google Patents

Description

March 25, 1952 TRIPLETT 2,590,354

DETACHABLE LATCHED ELECTRICAL PLUG AND SOCKET CONNECTION Filed Sept. 27, 1950 s Sheets-Sheet 1 FIG. I 3 1 28 24 y N i 27 LEE TRIP LETT INVENTOR ATTORNEY S March 25, 1952 TRlPLETT 2,590,354

DETACHABLE LATCHED ELECTRICAL PLUG AND SOCKET CONNECTION Filed Sept. 27, 1950 5 Sheets-Sheet 3 FIG. 7

FIG. 8

LEE TRlPLETT, INVENTOR BYMI 15,, W

1 ATTORNEYS Patented Mar. 25, 1952 DETACHABLE LATCHED ELECTRICAL PLUG AND SOCKET CONNECTION Lee Triplett, Magna, Utah, assignor of one-third to James L. Jones and one-third to Richard A. Sweet, both of Salt Lake City, Utah Application September 27, 1950, Serial No. 187,079

The invention of which the following is a detailed specification relates to a quick detachable latched electrical connection suitable for a wall or utility outlet. It comprises a fixed structure mountedin 'a wall box and providing suitable sockets which cooperate with the prongs of attaching plugs.

In the usual practice of supplying electric current from fixed outlets to portable electrical attachments, any tension or slight pull on" the electric cord is apt to break the electrical connection, or even dis-connect the plug from the outlet fixture itself. Thus, in the use of ordinary domestic appliances, such as electric pressing irons, electric cooking utensils and the like, interruption of the current may be caused Without the operator being aware of the fact until later. This results in much lost time.

Again, it is frequently the case that such an inadvertent interruption of the current will be of material damage where articles are being operated on by electrical attachments and continuous electric supply is essential to uniform work on product. Thus, an accidental interruption of current may cause irregular effects in paint spraying, electric welding, soldering, grinding, polishin and sanding.

An object of my'invention is to provide asimple but effective latch against inadvertent detachmentof the electrical connectors dueto normal direct pull on the electric cord. At the same time, theinvention will permit an emergency separation' by a stronger pull.

A further object of my invention isto provide spring means by which the connecting plug will beheld in firm, latched position. I

Astill further object of my invention is to permit ready detachment of the electrical connection by a. small tilting movement of the plug relative to the outlet fixture.

,Amongthe objects of my invention is to improve the typeof contact between the fixture and the prongs of the plug.

It is also a further object of my invention to keep the prongs of-the plug in separate compartments, thus avoiding the possibility of short- .circuiting.

Among the objects of'my invention is also provision-to compensate for ordinary wear on the plugs or weakened spring contact of the currentcarrying spring fingers. Theinvention has'been illustrated for the purpose of example in the accompanyin drawings in which I have illustrated the preferred form and where:

Claims. (01. 173-330) Fig. 1 is a front view of the utility outlet fixture showing the improved socket members;

Fig. 2 is a front view of the fixture with the cover removed;

Fig. 3 is a side elevation of the fixture partly in section taken along the line of line 3-3 of Fig. 1, showing the connecting plugs inserted;

Fig. 4 is a vertical section of the upper unit taken on the line 6-4 of Fig. 2.

Fig. 5 is a front view of the center plate;

Fig. 6 is a side elevation of the same;

Fig. '7 is a side elevation of the supporting bar;

Fig. 8 is a, side elevation of the socket member;

Fig.9 is a vertical section on the line 99 of Fig. 2; and

Fig-10 is-a side elevation of the plug.

In brief, the invention comprises an improved socket member in combination with a plug which has been modified to cooperate effectively with the improved socket. The socket is maintained in a tiltable floatin position by being pivoted to the frame members. Each socket member is bifurcated to provide spaced parallel compartments extending rearwardly. Each compartment contains one resilient spring finger which carries the current.

Each compartment is traversed by a springheld latch bar or detent to which the prong becomes fastened in normal operation.

The'plug is inserted in the face of the socket member, and one prong passes rearwardly through each compartment. In the operation of insertion, the end of the prong contacts the latch, and this causes the plug and socket to be tilted in order that the prongs may pass the latch bar.

This tilting movement may be anticipated by the operator, thus facilitating engagement of the parts.

As soon as the latch bar has dropped into the locking notches of the prongs, a holding spring operates to restore the socket and plug into the normal position in the plane of the cover.

As illustrated in the accompanying drawings, the preferred form of my invention consists in a novelsocket and plug arranged to be mounted in the present-day wall box H. Thesewall boxes are-familiar and include a cover plate I2. This cover plate is attached by means of a fastening screw I3.

The remaining visible portions are one or more socket members l4 into which the plugs l5 are inserted.

The wall box ll carries alon its longitudinal axisa mounting strap l6. This strap has tongues I! :by which it is bolted to the inwardly'extending flange or tongues'of the wall box.

The strap I9 is of metal which has been bent into a special form but in ordinary use has the rigid form illustrated in Fig. '7. Inwardly of each tongue I! the strap I6 is bent backwardly and ends in a bight i8. These bights serve to grip locking pins l9, l9 tightly and hold them in position. Inwardly of the bights l8, IS the strap |6 carries outwardly projecting resilient springs 26, 20. These springs are used to maintain the socket members in the plane of the cover plate l2.

The locking pins l9, l9 extend beyond the sides of the strap I6 in the manner shown in Fig. 2. The pins |9, |9 are of wood, composition, or other suitable electrically insulating material.

The strap H at its mid-point is enlarged to form a circular portion 22. This portion has peripheral tongues 23.

A bridge 24 made of plastic or other insulating material is formed with a series of slots 25. These slots are spaced to conform to the tongues 23. The tongues 23 are passed through the slots 25 and bent over so that the bridge 24 is rigidly mounted on the strap I6.

A nut 26 is firmly held centrally of the bridge 24. This nut receives screw I3 which holds the cover plate in position.

The bridge 24 on its outer side flanges 2'1, has a plurality of grooves 28.

The bridge 24 serves as a mounting for a pair of terminal bars 29. These are of conducting metal and are mounted on the sides of the bridge 24 by means of screws 30. Lugs 3| project inwardly from the bars 29 and are held within the grooves 28, 28. The screws 3|] form binding posts by which wires are fastened to connect the bars 29 to opposite sides of an electric circuit.

A rivet 32 passing through each end of the bars 29, forms a pivot for holding a socket member |4, |4.

Each socket member consists of plastic or similar insulating material having an enlarged slotted head 33. This head consists of two rearwardly extending sockets 34, 34. These sockets are reinforced at the corners by ribs 35, 35.

Each socket 34 is separated from the companion socket by a space slightly in excess of the width of the strap Hi.

The sockets 34, 34 are slotted as at 36 to provide clearance to receive the lock pins I9. The slots 36 extend to substantially the center or axis of the sockets 34, as shown in Fig. 4.

The front portion 33 of the socket member rests against spring 29 so that the socket member normally lies in the plane of the cover plate, as shown in full lines in Fig. 4. However, the rivets 32 form pivots around which the sockets may tilt into the inclined positions shown in dotted lines in Figs. 3 and 4. This is accomplished by pressure upon the springs 20.

As the socket members tilt around the rivets 32, the lock pins l9, l9 ride up in the slots 36 away from the center of the socket members 34.

Each socket member 34 is slotted at one end to permit the terminal bars 29 to fit within the sockets as indicated in Fig. 2. Within the socket members and on the inner faces of the bars 29, a resilient metallic contact piece 31 is held by the rivets 32. This contact member 31 is in the form of a letter J. A tongue 43, struck up from the long side and sent across forms a contact (see Fig. 2). The rivet 32 forms a firm fastening between the fiexible contact 31 and the adjacent terminal bar 29, as well as providing the pivot around which the socket member may oscillate.

The plug |5 has a body 38 of the usual form and terminal connections of the usual type to the 2-wire electric cord 39. Each plug has a pair of independent prongs 40, 40. The prongs are spaced parallel and go into the slots provided in the socket members l4.

Each prong is notched, as shown at 4|, on opposite sides to provide an opening large enough to receive a lock pin IS. The prong 4| has sliding contact with the short arm of the contact 31, as shown in Fig. 2.

A desirable feature is the provision of an open slot 42 in the prong between the notches 4|, 4| (see Fig. 10).

In the event that continued use enlarges the notches 4|, 4|, they may be spread apart to increase the frictional engagement with the pin I9. By notching opposite sides of each prong, the plug is reversible in position.

The plug is inserted in the slots of the socket member until the prongs strike the pin IS. The curved end of the prongs deflect the latter and this movement may be assisted by manually tilting the plug and the socket member into the position shown in dotted lines in Figs. 3 and 4.

This permits the prongs to ride over the lock pin l9. The lock pin then falls into the notch 4| of the prong and the spring 20 restores the socket member and the plug to the full line position shown in Fig. 3.

This attachment of the plug is reasonably secure against inadvertent dislodgement. The locking pin holds the prongs of the plug against normal pull in the perpendicular direction. The

' stress is transmitted directly to the wallbox cal through the strap l6.

Detachment of the plug is easily accomplished by tilting the socket member around the pivot 32. This compresses the spring 20. It also lowers the prongs of the plug to a position where they are no longer held by the locking pin. Hence they may be drawn out freely.

The above described arrangement provides a simple, durable and effective means for effecting the connection of electrical devices to the con- 2 ventional circuit outlets. It is adaptable for present-day equipment. It is easily operated but at the same time not subject to inadvertent detachment.

While the preferred form of the invention has been illustrated. and described, many changes in minor details of construction, proportions and materials may be made without departing from the scope of the invention as defined by the following claims.

What I claim is:

1. In combination, a fixed wall box, a median strap mounted thereon, a center plate on the strap, a pair of parallel contact bars held by the center plate, a socket member tiltably pivoted on the adjacent ends of the contact bars, said socket member being transversely slotted, a locking bar on the strap for projection into the socket member, and a plug having a pair of notched prongs insertable in the socket member and in looking engagement with the locking bar.

2. In combination, a fixed wall box, a median strap mounted thereon, a center plate on the 3. In combination, a fixed wall box, a median strap mounted thereon, a center plate on the strap, a pair of parallel contact bars held by the center plate, a socket member tiltably pivoted on each pair of adjacent ends of the contact bars, said socket member being transversely slotted,

" locking bars on the strap for projection into each socket member, spring contacts attached to each contact bar within the socket members, said spring contacts having opposed portions, and plugs having pairs of notched prongs insertable between said portions of the spring contacts and engaging the said locking bars.

4. In combination, a fixed wall box, a median strap mounted thereon, a center plate on the strap, a pair of parallel contact bars centrally anchored to the center plate, a socket member tiltably pivoted on each pair of adjacent ends of the contact bars with the said ends transversely disposed within the outer walls of the socket members, resilient contact members within the socket members, pivots passing through the contact members, the ends of the contact bars and the outer walls of the socket members, and plugs having pairs of notched prongs insertable between and engaging said contact members, said socket members having transverse slots on their inner walls and a locking bar mounted on the median strap for reception through said transverse slots and engagement with said notched prongs. a

5. In combination with a wall box, a median strap having ends for attachment to the box, intermediate bights, transverse locking bars held in the bights and springs opposite the locking bars.

LEE TRIPLETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,281,739 Wright May 5, 1942 2,447,597 Reed Aug. 24, 1948 2,473,570 Chirelstein June 21, 1949 FOREIGN PATENTS Number Country Date 177,713 England Apr. 6, 1922

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