US1979958A - Electrical plug device - Google Patents

Description

Nov. 6, 1934. P CLARK, JR 1,979,958

' ELECTRICAL PLUG DEVICE Filed .April 13; 1952 3 Sheets-Sheet 1 nvenfor /7 /4 www Q Ceo/0kg@ Gttomeg NIWe 6, E934., P, CLARK, JR 1,979,958

ELECTRICAL PLUG DEVI CE Filed April 15. 1952 3 Sheets-Sheet 2 NOV, 6, 934. A P, CLARK, JR 1,979,958

ELECTRICALl PLUG DEVICE Filed April 13, 1932 3 Sheets-Sheet 3 Snnentor Gttorneg Clim/Jagt.

Fammi APatented Nov. 6, 1934 UNITED STATES PATENT lOFFICE The present invention relates to improvements in electrical plug devices, and has for an object to provide in such a device a plug and. Contact unit which may be formed of onepiece of metal, will be inexpensive and reliable in construction, and will provide a positive, nrm, and reliable contact. A further object is to provide a construction in which the plug contact units may be assembled with great facility and will be *securely held in the insulating housing against displacement and distortion. Another object is to provide a housing which may be conveniently molded, and which will have the desirable characteristics of light weight, compactness and strength, and which will atthe same time provide ample room for the convenient attachment of wires. A

With the above and other objects in view embodiments of the invention are shown in the accompanying drawings, and these embodiments will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawings:

Fig. 1 is a side elevation of an electrical plug device, embodying the invention, and showing in dot-and-dash lines another plug device inserted therein.

Fig. 2 is a planview of the device.

Fig. 3 is a vertical sectional view, taken along theline 3-3 of Fig. 1.

Fig. 4 is a vertical sectional view, taken alng the line 4 4 of Fig. 3.

Fig. 5 is a perspective view of the plug and resilient contact unit, accordingto the invention. Fig. 6 is a side elevation of the insulating housing employed.

Fig. 7 is a plan view of the insulation housing.

Fig. 8 is a plan view of the closure plate employed.

Fig. 9 is a lplan view of an insulating housing, employed in a modied form of the invention.

Fig. 10 is a plan view of the closure plate employed with the housing as shown in Fig. 11.

Fig. 11 is a vertical sectional view of the modified form of the invention employing the housing and cover plate shown in Figs. 9 and 10.

Fig. 12 is a side elevation thereof.

Fig. 13 is a side elevation turned 90 from the side, as shown in Fig. 9, and with the Closure plate removed.

Fig, 14 is a perspective view of the clamping ring employed in the modification shown in Figs. 9 to 13.

Fig. 15 is an elevation of-a portion of an insu-t lation housing similar to thatshown in Fig. 13, but with a modied form of clamping lug.

Fig. 16 is a fragmentary perspective view of a modified form of clamping ring for cooperation e0 with the lug illustrated in Fig. 15.

Fig. 17 is a top plan view; partially broken away, of an electrical plug device according to a further modified form of the invention.

Fig. 18 is a side elevation thereof.

Fig. 19 is a side elevation, turned 90 from the side as shown in Fig. 18.`

Fig. 20 is a top plan viewof the insulating housing employed. Y

Fig. 21 is a sectional view, taken along the line 21-21 of Fig. 19, and showing in dot-and-dash lines another plug device inserted therein.

Fig. 22 is a perspective viewof the plugandl resilient Contact u'nit employed in the modication illustrated in Figs. 17 to 21.

Fig; 23 is a plan view of the closure ployed.

Similar reference characters indicate corresponding parts throughout the several figures of the drawings. Y

Referring to the drawings, the insulating housing or shell of the plug device, according to the embodiment of the invention illustrated in Figs. 1 to 8, is preferably molded from hard rubber, bakelite, or other suitable material, and is of generally cylindrical hollow form, comprising a cylindrical side wall 10 and a base l1, the side wall having at its upper end an outwardly onset cylindrical portion 12, connected to the main cylindrical portion 10 by an annular rib 13, which also serves the triple purpose of providing a ledge for protecting the edge of the clamping ring, a continuous annular reinforcement, and a :linger engaging'portion for enabling the plug to be conveniently inserted or removed from a socket element. A lead Wire opening 14 is provided in the side wall 10 extending downwardly from the upper edge, its upper end portionbeing spanned by the rib 13. -It will be observed that the inner plate em wall of the portion 12 is substantially ush with the outer surface-of the portion 10, so that in molding the housing' the opening 14 may be formed by a part on the mold core from which the housing may be stripped by a straight pull.

A vertical partition wall 15 is provided within the housing shell in the central plane intersecting the center of the-lead wire opening, a

lead wire cut out 16 being provided therein adjacent the opening 14. The edge of this cutout is designed so that it may. also be formed by a POLQIL Qi the mold core and will not interfere with the 4stripping of the housing shell from the core by a straight pull. The upper edge of the portion 12 is provided with a series of projections 17 for interlockingly engaging cutouts in the closure plate, as will hereinafter more fully appear. Upon the outer side of said portion 12 there is formed a single narrow, slightly projectthread 18 of the portion 12.

In assembling the plug and contact unitsthe ing, large pitch screw thread 18. The arrangement of this thread in relation to the vrest of the housing structure lis such that it will not interfere with the stripping of the housing shell from the mold by a straight' pull, the material being suiciently elastic at the moment of stripping to permit this.

In the base 11 there is provided in the compartment at each side of the partition Wall 15 a relatively thick platform portion 19, having a rectangular recess 20 therein and in the base of which is formed a plug receiving slot 21. The side walls of the recesses 2t are beveled at the upper portions, as at 22, for guiding the contact portions of the plug and contacting units therein, and the exterior edges of the slots 21 are beveled, as at 23, to guide the entrance of plugs therein.

A pair of plug and contact devices or units are secured in the insulating housing, and each is preferably formed by bending a strip of suitable metal upon itself, as at 24, to form a double thickness substantially rigid plugging portion 25, the two legs being bowed outwardly at the base of the plugging portion, as at 26 and 27, and extended in converging relation to form contact portions 28 and 29. The bowed portions 26 and 27 provide spring ends for the contact portions 28 and 29, so that they may be sprung apart into parallel plug contacting relation, without bending them between their ends, the spring action takingplace in thejbowed portions. The ends of the contact portions 28 and 29 are iiared outwardly, as at 30 and 31, to provide plug guidingsurface's. The plugging portion 25 is provided adjacent the bowed portions 26 and 27 with an extended threaded hole 32 inv which a binding post screw 33 is screwed. In forming the extended threaded hole the side leg at the head side ofthe screw is punched with a hole slightly larger than the screw and the other side leg is pierced and extended and the opening therein threaded.

The plugging portion 25 is provided near its upper end with a hole 34, and the contact portions 28 and 29 are provided with inwardly pressed bosses 35 and 36 respectively, which are adapted to snap into the hole 34 of a similar plug unit when the latter is plugged into the device, as shown in Fig. 1.

The cover plate 37 is provided with a pair of slots 38-38 'in linewith the slots 21-21 in the base, and in its periphery there is provided a series of cutouts 39 adapted to interlockingly engage the projections 17 at the upper edge of the housing shell. The cover plate is clamped down upon the housing shell byvmeans of a threadedy engaged with the plugging'portio'ns 2.5-V are insertedthrough the slots'38--38 oi "the cover plate in which they preff'er'alrllyl 'engage wth'a snug-fit, andthe contaci-[portionsk are then placed in the housing at they respective sides ,of lthe y `partition walll l5, the fiaredends'Ofand 31 being engaged in the rectangularfpockets R20-20;* 'The cover 'plate is thereuponclamped'in'place by the clamping ring Y@1o-s @timeagira matarla to the units before they are inserted in the housing. It will be observed that the pockets 20-20 position the units vertically while at the same time permitting the contact portions 28-29 to be separated upon insertion of a plug between them, as shown in dot-and-dash lines in Fig. l.

In Figs. 9 to 14 I have illustrated a modification, similar in 4general arrangement to the form illustrated in Figs. 1 to 8, but in which the housing shell 10a is provided at its upper end with a series of lugs 41 projecting upwardly and also projecting laterally and extending for a short distance downwardly upon the outer surface. The under side 42 is slightly inclined to form the projection into a wedge, and at the lower end of the incline there is provided a stop lug 43.

The closure plate 44 is provided with slots 45-45 in alignment with the slots 21-21 of the base, and at its periphery is provided with cut outs 46 adapted to interlockingly engage the lugs 41 of the housing shell. A flanged clamping ring 47 having an outer vertical side and upper and lower laterally disposed flanges is provided in its lower ange with a series' of cutouts 48 adapted to be engagedover the lugs 41 and upon turning of the ring to have one end brought into wedging engagement with the inclined under surface 42 of the lugs to thus clamp the closure plate in place, the stop lug 43 limiting the turning of the ring. A cut out 49 in the side and bottom flange registers with the lead wire opening 14 in the clamped position of the ring.

In the modification illustrated in Figs. 15 and 16 the under surface of the lug 41a is corrugated, and the lower flange of the ring 47 is provided with a pressed in boss 50 adjacent the end of the cut out 48 for yieldingly engaging the corrurgations, the stop lug 43a limiting the turning of the ring.

In Figs. 17 to 23 I have illustrated a further modification of the invention comprising an insulating cup-shaped housing shell 51, the side wall of which is cylindrical at its upper'portion and contracted toward the base so that it may be conveniently gripped by the fingers. A post 52 is integrally formed centrally of the base, its upper end being slightly below the upper edge of the side wall, and reinforcing and guide walls 53 and 54 extend in opposite directions from opposed sides of the post to the side wall. Diametrically opposed cut outs 55 and 56 for lead wires are provided in the upper end of the side wall, and cutouts 57 and 58 are provided in the upper ends of the walls 53 and 54 for extending lead wires from the binding posts to said openings 55 and 56.

The side wall is provided adjacent the walls 53 and 54 with vertically disposed channels 59 and 60, extending downwardly from the top edge and terminating in laterally disposed shoulders or ledges 61 and 62 respectively.

Within the base and at opposed sides of the post 52 there are provided slots 63 and 64, disposed at right angles to the walls 53 and 54.

A pair of plug devices or units are secured in the housing, and eachv is preferably formed by bending a strip of suitable metal upon itself, as

`portion, as' at'67 `and'68,`to form a shoulden'and extended inslightly converging relation, as at' `69'and 70 tojform contact portions.

portions 4 4 contact portions 69: and7p, sorthat they'may be The bowed A 67 andV 68 provide spring" ends for the sprung apart Without bending them between their4 ends, the spring action taking place in the bowed portions. The contact portion 69 is bent laterally, as at 71, and is provided with an extended threaded hole 72 to receive a binding post screw 73, and the other contact portion 70 is ared at its ends, as at 70a to provide a plug guiding surface.

The plugging portion 66 is provided near its upper end with a hole 73, and the contact portions 69 and` 70 are provided with inwardly pressed bosses 7474 respectively, which are adapted to snap into the hole 73 of a similar plug unit when the latter is plugged into the device, as shown in dot-and-dash lines in Fig. 21. The guide walls 53 and 54, which extend to the closure plate 76 adjacent the slots 80 and 81 each provides a guide to insure properly aligned insertion of the plugging' portions.-

In assembling the units the plugging portions 66 are projected through the slots 63 and 64 in the base of the housing, the shouldered portions 67-68 abutting the base -at the inner side, and a depressible finger 75 formed on one of the legs of the plugging portion engaging at the outer side to thus retain the unit against displacement and accidental removal. It will be understood that in inserting the unit the finger 75 will be depressed as it passes through the slot and will snap into locking relation when the unit is fully in serted. The laterally bent portions 7l are engaged in the channels 59 and 60 upon the ledges 61 and 62 in'such relation as to position the unit, while at the same time permitting a slight out- Ward and inward sliding movement of said portions 71, as plugging ends are engaged with and disengaged from the contact portions 69 and 70.

A cover plate 76 is seated within the open end of the housing upon the upper end of the post 52 and is provided with projecting lips 77 and 78 which engage the lead wire openings, the lead wire openings preferably having ledges 79-79 upon which the lips rest. Plug receiving slots 80 and 81 are provided in the plate in line with the slots 63 and 64 of the base, and a center hole 82 is provided between them -in which the securing bolt 83 is engaged, this bolt being extended through a passage 84 in the post 52, and having a nut 85 upon its threaded end disposed in a countersunk recess 86 in the lower end of the post. I have illustrated and described preferred and satisfactory embodiments of the invention, but it will be obvious that changes may be made therein, within the spirit and scope thereof, as dened in the appended claims. v

Having thus described my invention what I claim and desire to secure by Letters Patent is:-

1. In an electrical plug device, a housing of insulating material having a plug receiving opening, and a metallic plug and resilient contact unit carried in said housing, comprising a single strip of metal bent upon itself for a portion of its length to form a double thickness plug portion adapted to project from said housing the two sides of said strip being bent outwardly adjacent the base of said double thickness plug portion symmetrically at each side of the central plane of said plug portion to form outwardly movable springy portions and being extended from said springy portions to form a pair of single thickness contact portions, said contact portions being disposed in relation to said plug receiving opening to receive a plug between them.

2. In an electrical plug device, a housing of insulating material having a plug receiving opena pair of single thickness extensions integral with said double thickness plug portion and forming opposed resilient contact portions, one side of said double thickness plug portion having a threaded opening within the housing and the other side having an opening aligned with said threaded opening and a headed lead wire attaching screw carried by said double thickness plug portion engaged through said last mentioned opening and screwed into said threaded opening adapted to secure the two sides of said plug portion together, said contact portions being disposed in relation to said plug receiving opening to receive a plug between them.

- 3. In an electrical plug device, a housing of insulating material having a plug receiving opening, and a metallic plug and resilient contact unit carried in said housing comprising a single strip of metal bent upon itself for a portion of its length to form a double thickness plug portion adapted to'pr'oject from the end of said housing and a pair of single thickness extensions longitudinally aligned with said plug portion and forming opposed resilient contact portions, said contact portions being disposed in relation to said plug receiving opening to receive a plug between them, one of said portions being extended laterally to provide a lead wire attaching means.

1 4. A metallic -plug and resilient contact unit for use in an-electrical plug device having a plug receiving opening, comprising a single strip of metal bent upon itself for a portion of its length to form a double thickness plug portion and a pair of single thickness extensions integral with said double thickness plug portion vand forming opposed contact portions adapted to receive a plug inserted in said plug receiving opening between them, the two sides of said strip being bowed outwardly between said double thickness plug portion and said single thickness contact portions to form springy portions.

5. In an electrical plugV device, a cup shaped housing of molded insulating material having a side wall including an outwardly offset circumferentially continuous collar portion adjacent its upper end, an annular shoulder upon the inner surface of said side wall formed by the offset of said collar portion there being a lead wire opening in the side wall below said collar portion, said opening having non-converging sides extending to said shoulder and being vertically clear and entirely inwardly disposed with respect to the inner surface of said collar portion, and metallic contact units within said housing.

6. In an electrical plug device, a housing of insulating material having a plug receiving opening, and a metallic plug and*1 resilient contact unit carried in said housing comprising a single strip of metal bent upon itself for a portion of its length to form a longitudinally extending double thickness relatively stiff plug portion adapted to project from,said housing and a pair of longidinally extending single thickness extenresilient contact portions, said contact portions being disposed inrelation to said plug receiving opening to receive a plug between them, the plug said double thickness plug portion disposed symmetrically at each side of the central plane of said plug portion and forming opposed contact portions adapted to receive a plug inserted in said plug receiving opening between them, the plug receiving space between said contact portions being longitudinally -aligned `with said plug portion whereby the corresponding plug portion of an identical plug device may be engaged therewith. Y

' LANCASTER P. CLARK, JR.

Y. L .150v f DISCLAIMER 1,979,958.Lancaster P. Omrk, Jr., Fairfield, Conn. ELECTRICAL PLUG DEVICE. Patent dated November 6, 1934:. Disclaimer filed March 13, 1941, by the assignee, Elecmc Pug, Inc. Hereby enters this disclaimer to Claims l, 4, 6, and 7 in said speeiflcaton,

[Ofic/al Gazette April 8, 1941.]

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