US2720636A

US2720636A - Surface receptacle

Info

Publication number: US2720636A
Application number: US333104A
Authority: US
Inventors: Benjamin P Mckinley
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-01-26
Filing date: 1953-01-26
Publication date: 1955-10-11
Anticipated expiration: 1972-10-11

Description

Oct. 11, 1955 E. P. MCKINLEY 2,720,636

SURFACE RECEPTACLE Filed Jan. 2e, 1955 United States Patent O SURFACE RECEPTACLE Benjamin P. McKinley, Evanston, lli.

Application January 26, 1953, Serial No. 333,104

3 Claims. (Cl. 339-192) This invention relates to surface receptacles of the character adapted to be secured to a wall for receiving the plug of a cord for an electric range, for example, in supplying current to the latter.

Receptacles of the character under consideration usually are of the three terminal type for use in conjunction with the three wire systems generally employed in supplying current to electric ranges or other like current using apparatus. The conductors for the relatively heavy current supplied to such receptacles generally are in the form of cables consisting of two relatively large rather stif conductors of several wires each and a third conductor consisting of wires of smaller gauge and of considerably greater flexibility. In making installations of such receptacles it is desirable that the terminals to which the conductors are to be attached be such that the attachment can be effected expeditiously by an electrician without having to sharply ex or bend the stiff cables in attaching them to the terminals and also without the necessity of handling separable parts of cable attaching means which may be dropped and lost or otherwise occasion loss of time of the electrician. In addition to providing a novel construction and arrangement of parts which facilitate installation and hook-up of the receptacle, it is an object of the invention also to provide a construction all the parts of which can be assembled readily into an operative unit for packaging at the factory without loose parts which must be individually handled and assembled by the workman at the time of installation of the receptacle.

Another more specific object of the invention is to provide a receptacle of the character mentioned which is provided, preferably, with three terminals for a three conductor supply circuit to which terminals the conductors can be attached without substantial lexing and bending into position for attachment, and at least two of which terminals have slidable clamping members for securing the relatively stiif conductors to the terminals.

Other objects of the invention relate to various features of construction and arrangement of parts which will be apparent from a consideration of the following speciiication and accompanying drawing wherein:

Figure l is a front elevational View of an assembled receptacle of a construction which is illustrative of the present improvements;

Fig. 2 is a side elevational View of the receptacle shown inFig. l;

Fig. 3 is an elevational view of the receptacle with the cover plate removed;

Fig. 4 is a bottom view of a detached molded three cell insulating housing for the receptacle contact members which are shown in position in the cells and illustrating also the conductor clamping means each forming a part of one of the contact members;

Fig. 5 is an enlarged longitudinal sectional view taken along lines 5-5 of Fig. l;

Fig. 6 is a broken sectional view taken on line 6 6 of Fig. 5;

ice

Fig. 7 is a plan View of the central terminal member shown in Fig. 6;

Fig. 8 is a sectional View of the terminal member taken on line 8 3 of Fig. 7; and

Fig. 9 is a sectional View taken on line 9-9 of Fig. 7.

in Fig. l of the drawing a front elevational view of the improved receptacle is shown in assembled relation, which in use is adapted to be secured to a wall at a convenient location with respect to the current using device which it is to serve, generally an electrical range of the type used domestically. rlhe receptacle shown comprises a metal base 10 (see Fig. 5) integral with an end 11 which constitutes the lower end of the assembly when installed for use. Secured to the other or upper end of the base is an insulating receptacle or housing indicated generally by the numeral 12 which is attached to the base 10 after assembly therein at the factory of the spring contacts later described. The housing is attached to the base 10 by a single screw 13 as shown in Fig. 5. Preferably a nib or small projection 14 is provided on the perimeter of the end of the housing 12 which fits within a small cut out or recess 15 provided in the base for resisting angular displacement of the receptacle with respect to the base after securement of the parts together by means of the screw 13.

The housing 12 has three

cells

16, 17 and 18 for receiving

electrical contact members

19, 29 and 21 prior to attachment of the housing to the base itl. A fourth cavity 22 is shown but it is nonfunctional and is merely provided for reducing the quantity of plastic required in molding the housing 12. The three

cells

16, 17 and 1S, as stated, are adapted to hold the

contacts

19, and 21, but the contacts are provided with terminal members which extend from the cells at the inner or lower ends thereof as shown in Fig. 6. The contacts per se are identical and are adapted to make electrical contact with the blades of a three blade plug (not shown) when the blades are pressed through restricted openings or

slots

16a, 17a and 18a at the outer ends of the cells. While the

Contact members

19, 29 and 21 are similar, each has a terminal bar or extension peculiar to its location in the unit. The terminals designated 19a, 26a and 21a of the respective contacts are of bar form, the terminal 19a being straight while

terminals

20a and 21a are longer, as shown in Fig. 6, and are shaped angularly as indicated also in said iigure to group the terminal ends in substantial parallelism with the terminal 19a. The free ends of the terminals mentioned are turned inwardly, as indicated at 23, to space the terminals from an electrical insulating member 24 disposed between the contacts and terminals and the plate 10.

The

terminal members

19a, 20a and 21a are secured to the

respective contacts

19, 20 and 21 by any approved means, that shown in Fig. 8 being illustrative and consisting in partially punching from the end of the terminal strip the rivet-like extrusions 25 which are passed through openings in the contact and riveted over. Another attaching means may be used to provide good electrical Contact between the terminal strips and the contact members which are of copper, usually. The heads of the rivet-like extrusions 25 cooperate with the inturned ends 23 in spacing the intermediate portions of the bar terminals from the insulator 24.

Mounted on each of the terminal members 19a, 2tlg and 21a are cable receiving and clamping rings 26. The rings are rectangular in side elevation as shown in Fig. 9 and each is provided with a threaded passage at the upper side as viewed in Fig. 6, which carries a cable or conductor clamping screw 27. The ring 26 of the intermediate terminal strip 19a is closely disposed between the downwardly turned end 23 and the adjacent wall of the housing 12 and so is not slidable along the strip as are the rings 26 of the terminal strips a and 21a when the clamping screws are loosened. These sliding clamping rings are of substantial convenience in connecting the conductors of `aV cable 28 to the terminals in the receptacle. With the cover of the receptacle removed and the base plates secured to a wall by screws passed through suitable openings, such as openings 29 indicated in Fig. 6, and with the insulating housing and contacts in assembled relation upon Vthe base as the same comes from the factory, the cable is passed through a knock-out opening in the end 11 as shown or in the base 10 and clamped to the base by means of the usual outlet box clamps 30. The cable 28 shown is of the three conductor type, the intermediate conductor 31 being the return or ground conductor. Such Y a conductor, as shown, is usually formed of Wires of rela.-

tively small gauge and is quite flexible, and a workman l Vhas no difiiculty flexing it and inserting the bared end into the ring 26. of the terminal 19a. Tightening therespective screw 27 completes Vtherconnection of the conductor 31; The-conductors V32 and 33 are formed of a number of wires of relatively heavy gauge Vand are quite stiff. FleXing the'conductorsand inserting theminto openings, channels, or'rpassages designedV to receive 4them heretofore has sometimes constituted an annoying chore.

With the present improvements the rings 26 of the termi-l nals 20a, Zlaare merely pushed back or upwardly along the terminals in a direction away from the `free ends thereof and the workman then lays the stripped and bare, end of the conductor successively upon the respective terminals after which he slides the respective rings over the bared wires and tightens the screws 27 to complete the electrical connections. The cover plate 34 is then placed in position on the receptacle. l Y

The cover plate 34, of metal or plastic, comprises a front wall 35 and side walls 36. YThe forward edge of the 1 Vfront Wall rests upon shoulders 37 provided in the plastic `housing 12 .and at the opposite end has an inwardly turned portion 38 which overlies the inwardly disposed outer edge 11a of the rear wall 11. The wall 11 has a tab 39 provided with a threaded opening for receiving a' screw 40 passed through an opening in thel coverV for holding the latter in position as shown in Fig. 5. Y

It will be noticed that the rings 26 of the several terminals are confined Vthereon bythe downwardly turned ends 23 of the terminal bars and hence, even when the screws 27 are loosened the rings cannot drop oi the bars. The

' along said base plate and a ring loosely surrounding each screws 27 preferably are staked againstrcomplete Withdrawal from the rings and hence when a Workman removes the cover plate 34, he has an `integrated structure t to attach to the wall and towhich the electrical conductors Y are latter attached. The provision of the slidable rings 26 on the

terminalbars

20a and 21a simpliiies the work involved in attaching the relatively

stii conductors

32 and 33 as described.

While I have shown and described a surface receptacle which is illustrative of my improvements, variouschanges t in details may be resorted to withoutV departure from the terminal barfand provided with a conductor clamping screw for clamping a bared end of a conductor within the ring into electrical contact with the respective bar, two of said bars projecting from said housing a distance adequate to enable the rings thereon to be slid along the bar over the ends ofa conductor on the bar 'preparatory to clamping the conductor'to the bar. Y

2. A n electrical vreceptacle .comprising a base plate adapted to be attached to a wall, an insulating housing secured to said plate and provided with vcells for electrical contact members, said cells being open at the bottom ends and provided with passages at the outer ends for accommodating the blades of an loutlet plug inserted therethrough for electrical connection with contact members Within the cells, contact members Within the cells provided with bar terminals extending longitudinally of the plate, from one side of said housing and each having a free end Y turned ltoward y'said plate, Yan lelectrical insulatingrnember disposed between the plate and said vcontactmembersV and the bar terminals thereof .and engaged bythe inturned ends of said bar terminals forrspa'cing thelatter from said insulating member, and conductor .receiving-each looselysurrounding one of said -bar terminals and conined thereon by said housing and the inwardly `turned end of the vrespectiveV bar and. each provided 4with a clampV Y screw at least two of said Abars being of Ysuflicient length toV accommodate, sliding movement of the respective rings therealong to enable therings to be slid'upwardly of thel bars `and thus yenable ythetbared ends of conductors to` be placed upon the lower portionsof the bars and thereafterV Y slid downwardly `over said bared ends for attaching said ends to the bars by the respective screws.

, 3. An electrical receptacle comprising a baseY plate adapted to be attached to a wall,Y an insulating housing secured to the plate at one end thereof and provided with Y cells for electrical contact members, said cells being-open Y at -the ybottom Vends and provided with passages at the outer ends for 4accomrnodatingvthe blades of an Voutlet plug inserted therethrough 4for electrical connection with contact members within the cells, Contact members within said cells provided with Vbar terminals V.extending Vfromrzsaid,

housing longitudinally .of the tbaserand each-provided with afree enddirected inwardly toward-said plate, an insulating member on the-base beneath saidrcontact members and bar terminals, and rings on said bar terminals between theV inturned ends thereofV and said housing and :each provided with a clamping screw for clamping tothe bar terminal a bared end .of a Aconductor extending within the Y ring, atleast two ofl said bar terminals beingyof suicient length to enable said rings `to be slid awayfromsaid free end portions a distancegto enable the bared ends of 4condoctors to be placed onlsaid free end portions and thereafter moved to encompassing relation over said rconductor ends prior to tighteningfvthe screws for clamping the conductor ends into iirm .electrical contact with saidV `bar terminals.

References Cited in the file of this patentV UNITED STATES PATENTS Y1,967,901 Y Kempton July 17, '1934v 2,145,556 Rypinski June 31, 1939 2,193,202 Millermaster Mar. V12, -1940 2,203,337 Mebold June -4, V1940 32,287,762 Rogoff` Iune 23, 1942 2,602,104 Hubbell et al. 'luly l, 1952