US 2119428 A
Description (OCR text may contain errors)
May 31, l938.- 1.. e. ENGLAR PROTECT I VE ELECTR IGAL RECEPTACLE PLATE Original Filed Dec. 14, 1934 2 Shee ts-Sheet l May 31, 1933- L. G. ENGLAR 2,119,428
morncnvs ELECTRICAL RECEP'I'ACLE PLATE Original Filed Dec. 14, 1934 2 Sheets-Sheet 2 v INVENTOJ Patented May 31', 1938 UNITED, STATES PATIENT oil-Flor:
PROTECTIVE ELECTRICAL BECEPTACIE PLATE Lillian a. Crestwood, N. Y.
Application December 14, 1934, Serial No; 757,507
' Renewed September 9, 1936 4 Claims. (01. 241-23) This invention relates to an improved electric installation wall receptacle plate and more parlli from. It is well known that such is a common occurrence, especially as a result from tampering with the receptacles by children, that the inflicted injury oft times results in death.
It is therefore a feature of the present inven- 20 tion to overcome the present disadvantages of the receptacle plates and provide protective means to obstruct the apertures through which engagement of the normally live electrical contacts usually is made. I
It is a further feature of the invention to lock the protective means obstructing the contact apertures during the period the outlet or receptacle is inoperative, that is not in use. I
It is a further feature of the invention to re- 6 quire releasing means or a key to release theprotective means to render it operative for use.
I It is a further feature of the invention to provide for the protruding prongs of the standard insertable plug as a release key.
It is a further feature of the invention to require a proper setting of the protective means to.
render the receptacle operative for use.
It is a further feature of the invention to antomatically restore itself to its normal or pro- 4o tective position upon removal of the insertable Dlug. l
Further: and other features of the present invention will'be hereinafter set forth in the accompanying specification and claims and shown 45 in the drawings which by way of illustration is what I now consider to be the best modes in which I have contemplated applying that principle. Other embodiments of the invention em- Dloying the same or equivalent principle may be 50 used and structural changes made as'desired by those skilled in the art without departing from the present invention and within the spirit of the.
In the drawings: g as Figure 1'is a rear view of the device at an enlarged scale showing theoperating mechanism.
Figure 2 is a sectional view taken substantially on line 1-2 of Figure 1.
1 Figure 3 is a sectional view taken substantially guonlinel-lofl'lgurel.
' as to be rotatable.
Figure 4 isan elevational view of the device shown in Figures 1, 2 and 3.
Figure 5 is an elevational view of a modified form of the invention.
Figure 6 is an elevational view of a further 5 .modifledform of the invention in which a door type receptacle plate is employed.
Figure 7 is a detail sectional view of the modifled form shown in Figure 5.
Figure 8 is a detail sectional view of the modil0 fled form shown in Figured.
Figure 9 is an elevational view of a still further modification.
Figure 10 is a detail view in isometric oi the locking spring shown in Figure 7. 18
Referring now to thedrawings in which similar parts are designated by the same numerals in the several views, it is believed that a clear understanding of the invention will be had therefrom when considered in conjunction with the 20'" following description.
For the sake of clairifying the following description the description of the construction of the invention will be given first, then followed by a description of its operation, and then followed by a description of constructionand operation of several modifications of the invention.
General description Referring now to Figures 1, 3 and the vention is shown comprising a standard rectangular wall receptacle plate ll, of suitable material, preferably insulating material. having a relatively large circular opening ii, and provided with bevelled edges I2 and the regular countersunk screw holes I! located in the major axis of the plate. An integral part of the plate is shown in Figure 3 to consist of a plate member I bridging the circular opening ll adapted to have a blade spring I! mounted thereon and-.45
guide studs it which may be extension portions of the plate H or individual studs fastened thereto to retain the spring II in position. It is obvious that the member I need not necessarily be an integral part of the plate II, but could be separate therefrom and attached thereto in a convenient manner. Portions of the blade spring II near its extremities are bent upwardly as viewed in Fig. 3, the purpose of which will be ex plained presently. v r
Superimposed on theplatel' is a-circlilar disk n preferably of insulating material which is suitably fastened to plate member I byi pin ll so I diametrically located recesses II is fixedly attached to disk .i'l. Suitable openings or cutouts ll, preferably oblong shaped to conform to the regular shape of the prongs oi'lelectricai innertion plugs, are provided in l to per- An annular segment II with mit the ingress and egress of the usual electrical 1 16 are located over the blade spring as shown in Figure i, so as to permit the inserted. prongs of a plug, for example, to engage portions of the blade spring l5 so that the blade can be depressed by further insertion of the plug prongs to be displaced from the said recesses in the segment it. A suitable spring 22 disposed about pin it is attached to the disk ii and member it to positively return the rotatable disk ii to its normal position when displaced therefrom.
Operation it was previously mentioned that the openings or cut-outs iii in the superimposed disk in their normal locked position were located directly above the blade spring it, which is preferably a width practically equivalent to the length of the openings Eli, so that when the prongs of an elec tric plug or other: elements are introduced in the openings the spring will he engaged. go It is to understood that the present plate attached th the wall outlets in the same manner as the standard wail flush plate. The electrical contacts in a standard type of outlet are disposed along the major axis the plate i@ as indicated bythe dotted section Bhe bridged member i l and spring iii cred along the minor axis of the plate, so
s and the openings iii in the plate it. fore, it is seen with the disk il iii-its nord position the electrical contacts of the let are isolated in such a manner that tire elements cannot he introduced therethe disc ill is unlocked or released and through 9%)" to align the openings in. the dish w h the electrical contacts.
v noted that in order to release the its normally locked position the blade spr. g must be depressed at both of its extrec -es to clear the recesses 28 before the disk can e rotated. Thus, the insertion of an elein one opening in the disk will not release v i. to permit its rotation. 'Iwo elements must he inserted simultaneously to engage the spring i5, -for example, the prongs 23 of an electric plug 24. The prongs must be in.-
serted sufilciently to overcome the spring action ,0 to displace the extremities of the spring ill from the recesses in the said segment. This action releases the disk l7 and permits its rotation by the partly inserted prongs of the plug. When rotated through 90 and the openings 2! are 65 aligned with the outlet openings, the prongs of the plug can then be inserted to engage the electrical contacts.
'It is understood that the disk I! is rotated against the action of the fixed spring 22, so that is shown comprising two circular disks, a rotatable 'disk 25 with openings 26 superimposed on the plate 21, and a fixed disk 28 with openings or cutouts 29 attached to or integral with the plate 21.. Both disks to be preferably of insulating material. 5 A suitable pin 29a extending from the disk 25 to disk 28, has attached thereto a U-shaped spring 30 adapted to have its extremities fit into the cut-outs 25 in disk 25 to lock the disk in this position. Insertion of the plug prongs through the 10 openings in disk 25 engage the spring 36 to depress it to the extent that the extremities are forced to release disk 25. When the extremities of the spring are pushed downwardly to release the disk it may be rotated through Elli to align 15 the openings 28 with the cut-outs iii in disk 28 which are in turn positioned to correspond to the location of the electrical contacts or" the outlet box, in this manner permitting contact between the prongs of the plug and contacts of outlet 26 box. Upon removal of the plug the disk 25 is returned to its normal position by the spring 3! attached to the disks 25 and it, to be caught and locked by the spring 130.
In Figs. 6 and t, the principle is applied to the all hinged door type of receptacle plate where the openings 32 are provided in the door adapted to be held in a closed position by a cylindr al spring insulated circular with slots 36 adjusted to be positioned directly over it the outlet contacts fixedly attached plate ill and provided with additional slots 38 to per hilt the arms of the attached spring to pass therethroimh. The extremities spring arms are bent slightly to be a I to engage 3:3
locking studs Gil, fixed on the i e of the door and in this manner maintaining in a locked position. The releasing scion IS the same as described hereinbefore, ely upon insertion oi? the plug the arms dis- 4S placed from the studs to release e door. When the door is released and opened the plug is permitted to he through the openings 36 to engage the electi cal contacts oi e outlet. Upon removal or plug, the door by vL-tne of its spring 3G is restored to its closed cities and locked in same posit. n by the cooperating studs it.
In Figure 9 another modirication shown whereby the disk ii is separate from the plate 42. a The plate has embodied therein the circular disk 33 similar to the above described disks with slots id corresponding to the location of the electrical contacts to he engaged by the plug and slots permitting the arms of the described U spring 45 to extend therethrough so that when the disk It is in a lowered position the slots 46 are engaged thereby to lock the disk at in this position. The disk is provided with arms ll adapted to slide through the guides 48 attached to plate 42. The 00 disk M is released in the same manner by inserting the prongs of a plug to force the spring arms inwardly as viewed in Fig. 9, to be displaced from the openings 46 thereby permiting the disk to be raised and uncovering the slots 44 adapted to receive the plug prongs for engagement with the electrical contacts. Upon removal of the plug the disk falls by its own weight to automatically cover the contact slots 44 and as is obvious the ends of the U spring engage the slots 46 to hold the disk in a locked position.
It is evident from the description and disclosure of the principle of operation of the device that many modifications of the specific device shown are appareny and suggested so that it is not intended to be limited by the specific illustration of one form of the invention as shown.
It is also obvious that the application of the disclosed device is not limited to a single outlet receptacle but that it can be applied to a multiple outlet type in the same manner as disclosed for a single outlet receptacle. Its application to other forms of outlets is apparent as for example the standard convenient outlets in present day use, that is an outlet device used for extending an electrical circuit to other outlets in desirable positions without interfering with the continuity of the wire.
While there has been shown and described and pointed out the fundamental novel features of the invention as applied to several modifications, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.
What is claimed is:
1. A protective device, as a separate unit to be mounted over electrical outlets; said protective device consisting of a rotatable insulated disc. of sufllcient size to cover surface area of electrical outlet unit; said disc having plug openings, adapted by a turning movement to be brought into alignment with fixed electrical contact chambers inthe usual electric outlet; an axis or pin on which said disc may rotate; yieldable blocking and locking means between said rotatable disc and surface area of electric outlet unit, to definitely lock said disc, said locking means being -yieldable only by the pressure of simultaneous insertion of both prongs of a standard electric plus; means to automatically return said rotatable disc into normal locked position when standard electric plug prongs are removed from contact chambers, definitely closing said electric contact chambers when not in use.
' 2. An insulated, outer shell having a superimposed insulated disc, suitably fastened to the back support strip of said outer shell by' a pin so as to be rotatable, said disc having plug openings, adapted by a turning movement to be brought into alignment with fixed electrical contact chambers in the usual electrical outlet; a strip of blade spring held in position by said pin between said rotatable disc and a channel-shaped support across the back of said outer shell, in which channel-shaped support said blade spring rests; said blade-spring being shaped so that the two extremeties are slightly bent upwards toward the face of said outer shell, fitting into recesses on the back of the superimposed rotatable disc, and holding said disc in locked position when the electrical'outlet'is not in use; said blade spring a being positioned directly under the plug openings in said rotatable disc, so that by pressure of simultaneously inserted prongs oi! the standard electric plug through said openings in said superimposed disc. said blade spring yields and releases itself from the recesses, and permits the rotation oi said disc until theinserted prongs are directly over the electrical contact openings in the usual electrical outlet, permitting complete ingress of plug prongs; a coil spring disposed about the aforementioned pin, one end of said coil springbeingfastenedtothebacksupportofsaid insulatedoutershelLandthe otherendtothe back of the superimposed disc, said coil spring tending to return the superimposed rotatable disc to its normal locked position, to definitely close the contact openings in usual electrical outlets when the plug is removed from said electrical outlet.
3. An insulated outer shell, having a superimposed insulated disc suitably fastened to the back support strip of said outer shell by a pin, so,as to be rotatable, said disc having plug openings, adapted by a turning movement to be brought into alignment with fixed electrical contact chambers in the usual electrical outlet; a U-shaped locking device adapted to have its extremities fit into the plug openings in the superimposed disc, and thus lock said disc when the outlet is not in use, said U-shaped locking device fitted over the pin connecting the rotatable disc and back support strip of said insulated outer shell, said U-shaped locking device being adapted to yield when the extremities of the plug prongs are simultaneously inserted into openings in said superimposed disc; a coil spring disposed about aforementioned pin, one end of said coil spring being fastened to the back of the superimposed disc, and the other end to the back support of said insulated outer shell,
said coil spring tending to return the superimposed rotatable disc to its normal locked position, to close definitely the contact openings in the usual electrical outlet when the plug is reacross the back of said outer shell, in which channel -shaped support said blade spring rests; said blade spring being shaped so that the two extremities are slightly bent upwards toward the face of said outer shell, fitting into recesses on the back of the superimposed rotatable disc, and holding said disc in locked position when the electrical outlet is not in use; said blade spring being positioned directly under the plug openings in said rotatable disc, so that by pressure of simultaneously inserted prongs of the standard electric plug through said openings in said superimposed disc, said blade spring yields and re- I leases itself from the recesses, and permits thev rotation of said disc until the inserted prongs are directly over the electrical contact openings in the usual electrical outlet, permitting complete ingress of plug prongs; a coil spring resting in a curved recess in the inner wall of the said outer shell member, positioned so as to permit a turning movement of the said superimposed disc; a
lug in the bottom of the said rotatable disc, said lug extending into the said curved 'recess in the inner wall of the said outer shell member so as to tension the said coil spring when said disc is released for rotation from its locked position by the simultaneous insertion of the plug prongs.
against the blocking and locking means aforementioned; said coil spring returning the said superimposed rotatable disc to its normal locked position, to definitely close the contact openings in the said electrical outlet, when the plug is removed from said electrical outlet.