US 2408583 A
Description (OCR text may contain errors)
06L 1, M s b s CORD TERMINAL PLUG Filed July 'r, 1943 (JOHN M "SI 0N5 Patented Oct. 1, 1946 UNITED STATES PATENT OFFICE Claims. 1
This invention relates to an electric plug connection suitable for attachment to the end of an electric cord and the plug is to be thrust into a socket for completing the electric-circuit to a light or other electric fixture. The invention relates particularly to the construction of the blades and the plug and the mounting of the blades in the plug, which is for insertion into the standard'openings of an electric socket.
Among the objects of the invention are to so construct and relate the blades in the socket that they will maintain apositive contact with the contact members of a socket and so that they will maintain this positive contact over a long period of time and so that the contact will not be broken accidentally.
Other objects of the invention are to form leads on the points of the blades for insertion into the standard openings of a socket so that the blades may be twisted by the leads upon their insertion into the openings oi the socket and the blades will therefore readily slide into those openings. A further object of the invention is to so devise the plug and its blades that the blades will return to their primary position upon release from the socket. Another object of the invention is to construct the plug of resilient material, in which the blades will be firm- 1y held and which will be slightly distorted when the blades are inserted into the openings of the standard socket.
Further objects and advantages of the invention will appear from the following description and the accompanying drawing forming a part hereof. and in which:
Figure 1 is a cross-sectional view through a socket showing the blades therein.
Figure 2 is a plan view of the face of the improved plug showing the prongs or blades therein.
Figure 3 is an elevational view of one of the blades shown in Figure 1 and 2.
Figure 4 is a side view of a plug showing a slightly modified form of blade.
Figure 5 is a plan view of the plug and blades shown in Figure 4.
Figure 6 is an elevational view of a modified form of blade.
In the drawing similar numerals refer to similar parts in the several views.
The plug body I is preferably made of resilient rubber and it has in the center thereof an opening for the usual electric cord 2. This cord has two terminals, each of which is attached to one of the blades 3, each of the wires having the insulation removed from its end and the free 2 end is then passed through opening 4 in the blade and around notch 5, both to firmly hold the blade in the socket and to make a positive electrical contact with the blade.
The blades are so placed in the socket that" their longitudinal axial center lies within a common plane and so that they each hear an angle of nearly with that plane.
The blades are intended for insertion into the openings of a standard electrical contact socket having two rectangularly shaped parallel openings and in each opening there is one or more contact plates attached to a further electric cord or source of electric power.
In the preferred form shown, the blades are of rigid construction mounted in a resilient rubber base so that when the blades are turned to an exact 90 angle with the plane through their axial center, they distort the rubber base in which they are held. They are then under tension or tortional strain and tend to resume their primary position of nearly 90 with this plane. As shown in the drawing in Figures 1 and 2, the blades are set at an angle of approximately 20 from a plane through their axial center and in this form the standard distance between the blades is at their axial center so that they twist in reverse direction one to the other on both sides from this axial center upon insertion into the openings of the standard plug.
If desired, the extreme tips or ends of the projecting blades may be turned to or formed in a right angular position with the plane through the axial center of the blades so as to form leads similar to the openings in the plug and the blades then have sloping shoulders 6 slightly removed from their ends which tend to twist the blades to make them conform to the parallel position of the openings in the socket. In the form of Figures 1 and 2, these shoulders are on both sides of the axial plane through the blade centers, and turn the blades on their axes.
In Figures 4 and 5 the blades are fixed so that the standard width between them is at one edge I, of the blades, in this instance the lower edge in Figure 5. and in this instance the angle from the axial plane through them is shown as 10 and the twist of the extreme end to form the lead shoulder 6 i greatest at the other edge of the blade. and the blades are turned around their edges 1 as axes.
In the modified form of Figure 6, the blade end is cut off at an acute angle and the point 8 is at the edge of the blades spaced in the plug the standard distance apart, it would be edge I trated, is done against the restorative resilient and that force of the rubber body of the plug restorative force tends to hold the blades firmly in the openings in the socket and firmly against the contact plates in such openings.
There have been described idde'tailabovo and shown in the accompanying drawing, several modifications of this invention. It will be aparent h t t e inven on can be ar i d u in es-Y ap arently W el d f er nt embodim without d pa tin r m th s i i of th nve tion and within the scope o t the, claims. It is hsre ere n end q hat the m di i ations shown nd 'si s rihesi hqi l be nterpreted as illustrahis am; n t sums-less ns Having thus described the invention. what is claimed as new and is desired tp'be secured by ett rs atent 1 11 A e ectric l con act Plus h v ng h re n Is eii y 9 l n t dinal y Projecting po yg n. 1r cross-s ct oned b ad s t e hr st into correspondingly shaped openings in an electrical c t, ac la e ein m un ed n the plus in a on itudina y wisted Pos tion relative to t We s ei he c rre pondin pe i gs, nd being o me t pr vide n blique bi surface adapted to serve, as a sliding pressure surface, h reb he blade r closed er torsional ra upon t ei in er ion t e ei t 2- n electrical con ac lus having th po y o al. b e to, he t st ongi udinally i o err sp lidinslv sliepsd'openinss in an el cal oc et ea b asts bein immed in i l g at an angle, axially, to the walls of the corresponding opening, and being formed to provide an oblique biasing surface adapted to serve a a sliding pressure surface, to cause the twisting of the blade, at right angles to the direction of thrust, upon its insertion into said opening.
3. An electrical contact plug comprising a resilient body, having therein a plurality of Iongitudinally projecting polygonally cross-sectioned blades to be thrust into correspondingly shaped openings in an electrical socket, each blade being mounted in the resilient body in a longitudinally twisted position relative to the walls of the corresponding opening, and being jammed to provide an oblique biasing surface adapted to serve as a sliding pressure surface, whereby the blades are placed under torsional strain. in the resilient body upon insertion into said opening.
4. An electrical contact plurality of longitudinally projecting polygonally cross-sectioned blades to be thrust into correspondingly shaped openings in an electrical socket, ach blade being so mounted in the plug plug having therein a as to be placed under torsional strain by the walls of the openings upon-their insertion into said openings, the projecting end of each of said blades having a sloping shoulder to twist the blade body upon its insertion into the opening of the socket.
5. An electrical contact plug having therein a plurality of longitudinally projecting polygonally cross-sectioned blades to be thrust into correspondingly shaped openings in an electrical socket, each blade being mounted in the plug in a longitudinally twisted position relative to the walls of the corresponding openings, and being placed under torsional strain upon their insertion thereinto, the projecting end of eachoI said blades having a sloping shoulder to twist the blade body upon its insertion into the said corresponding opening of the socket.
J O SIGN