US 2390852 A
Description (OCR text may contain errors)
E. c. s-TEE ELECTRIC PLUG Dec. 11, 1945.`
Filed Jan. 16, 1943 Iuvento;
Patented Dec. 11, 1945 UNITED STATES PATENT OFFICE ELECTRIC PLUG I Ernest C. Stee, Bismarck, N. Dak. Application January 16, 1943, Serial No. 472,625
The present invention relates to new and useful improvements in electric attachment plugs and has for its primary object to provide, in a manner as hereinafter set forth, a novel construction and arrangement whereby the device will be held firmly in the receptacle or socket and good electrical contacts maintained at all times.
Another very important object of the invention is to provide an electric plug of the aforementioned character wherein .the prongs may be expeditiously removed from the body or shell to facilitate connecting conductor wires thereto, and then replaced.
Other objects of the invention are to provide an electric plug of the character described which will be comparatively simple in construction, strong, durable, highly 4efficient', and reliable in use, compact, attractive in appearance and which may be manufactured at low cost.
All of the foregoing and still further objects and advantages of the invention will become apparent from a study o' the following specincation, taken in connection with the accompanying drawing wherein like characters of reference designate corresponding parts throughout the several views, and wherein:
Figure l is a perspective view of an electric plug constructed in accordance with the present invention.
Figure 2 is a View in side elevation thereof.
Figure 3 is a sectional view, taken substantially on` the line 3-3 of Figure 2.
Figure 4 is a detail view in resilient, removable prong-retaining block.
Referring now to the drawing in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a substantially fiat body or shell I of hard rubber or other suitable insulating material. The shell I includes a substantially dovetail inner portion constituting a grip 2 the longitudinal faces of which are knurled or roughened, as at 3. The grip 2 further includes oppositely inclined ends 4.
As illustrated to advantage in Figure 3 of the drawing, the body I has formed therein a chamber 5. A comparatively narrow entrance passage Ii communicates with the chamber 5, the side walls of said entrance having formed therein sockets or depressions 1. The other end portion of the body I has formed therein an opening 8 which communicates with the chamber 5, which opening accommodates the conductor cord. The front 9 of the body I has formed therein a slot I which communicates with the chamber 5. The purpose of the slot I0 will be presently set forth.
Pivotally mounted in the body I and projecting therefrom is a pair of removable, normally diverging prongs II. Intermediate portions of the prongs Il are formed to provide substantially U- shaped, laterally projecting trunnions I2 which perspective of the are journaled in the sockets 1. A substantially wedge-shaped block I3 of resilient rubber is inserted and compressed in the entrance 6 between the prongs II for retaining the trunnions I2 in the sockets 1.
The inner end portions of the prongs Il have formed therein openings I4 for the passage of the skinned end portions of the electric wires I5. Threadedly mounted in the prongs II are binding screws I6 for firmly securing the wires I5 to said prongs.
It is thought that the manner in which the plug functions will be readily apparent from a consideration of the foregoing. Briefly, the resilient block I3 normally holds the prongs II in substantially the position shown in Figure 3 of the drawing. Thus, the outer ends of the prongs Il are too far apart to enter the usual socket or receptacle. To connect the plug, the prongs II are pressed inwardly or toward each other for engagement in the receptacle, thereby compressing the resilient block I3. In this manner the prongs II are constantly pressed outwardly or a-part for firmly securing the plug to the receptacle and for maintaining good electrical contacts. Of course, the prongs I I fulcrum or rockin the sockets 1. To remove the prongs I I from .the body I for connecting the wires thereto, the resilient block I3 is dislodged by inserting a suitable instrument through the slot I0. Removal of the block I3 permits disengagement of the trunnions I2 from the sockets 1 for withdrawing the prongs II fromthe body I.
It is believed that the many advantages lof an electric plug constructed in accordance with the present invention will be readily understood and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction may be resortedto which will fall within the scope of the invention as claimed.
What is claimed is:
An electric plug comprising a body having a chamber therein, certain of lthe opposed walls of the chamber having sockets therein, prongs mounted in the chamber and projecting from ithe body, said prongs including laterally bent portions constituting trunnions at an intermediate point journaled in the sockets for rockably sup porting the'prongs in the body, means for connecting conductor wires to the inner end portions of the prongs, and a substantially wedgeshaped resilient block engaged between the prongs under compression for retaining the trunnions in the sockets and for yieldingly urging the outer ends of said prongs apart, the body further having a slot therein communicating with the chamber for the insertion of an instrument for removing the block. i
ERNEST C. STEE.