US2915737A

US2915737A - Electrical power plug

Info

Publication number: US2915737A
Application number: US656938A
Authority: US
Inventors: Morse Milton
Original assignee: Morse Milton
Current assignee: COMPONENT ENTERPRISES COMPANY Inc A CORP OF PA
Priority date: 1957-05-03
Filing date: 1957-05-03
Publication date: 1959-12-01
Anticipated expiration: 1976-12-01

Description

Dec. 1, 1959 M. MORSE ELECTRICAL POWER PLUG 2 Sheets-Sheet 1 Filed May 3. 1957 infin/l fil: i l

Dec. 1, 1959 MMMM RSE 2,915,737

2,915,737 ELECTRICAL POWER PLUG Milton Morse,'Bronx, N.Y.

Application May '3, 1957, Serial No'. 656,938

4 Claims. (Cl. 339-1195)` This invention relates generally to electrical connectors and more particularly to power plugs of the double bladed type.

` Heretofore in connection with apparatus requiring a relatively heavy power supply, it has beencustomary to use connection plugs which were bulky, thus 'necessitating undue enlargement of the apparatus and particularly chambers adapted to receive the coiled wire and plug.

' It is therefore among the principal objects of the present invention to provide electrical connection plug construction of the bladed type, which is adapted to accommodate relatively large conductors and yet which is of unusually compact arrangement.

. Another object herein lies in the provision of electrical connection plug construction, whichl although compact, is extremely durable so that the plug may be subjected to considerable abuse without damage.

'4 Astill further object of the presentinvention lies in the provision of electrical connection plug construction in which the blade elements are supported at a plurality of points to assure rigidity and constant alignment even under considerable stress.

A feature of the invention lies in the fact that the insulating medium of which the body element is composed maybe of a rigid durable type adapted to resist the effect of heat and moisture. This medium, is equally adapted to resist the effects of extremely low temperatures. Insulating materials of this character, however, are subject usually to the objection of brittleness and low impact resistance to shock. By virtue of the coaction therewith of the shell element the body is reinforced and protected.

Another feature of the present invention lies in the provision of an improved formv of strain relief element which is strongly integrated with the shell element and which is adapted to securely engage the conductor with which the plug is used so that stresses upon the conductor are not communicated to the points of connection of the conductor with the contact screws.

Another object herein lies in the provision of structure whereby the permanent engagement of the blade element, with the body element, is quickly performed andpositively maintained.

One of the important requirements of plugs of the type described is that the blades maintain their position so that quick' and positive connection and disconnection may be made with a female type receptacle of standard predetermined dimensions. Since it is desirable to use a relatively brittle insulating medium for the body because of its weather and temperature resisting characteristics, it is desi-rable that the metal parts have a relatively tight t therein.' This raises the objection that when the parts are assembled, unless the tolerances are kept extremely fine, the brittle body will be shattered with a consequent loss in production. In accordance with the present invention, the resiliency characteristics of the material of which the blades are formed is taken advantage of, whereby the prong members on the bladeelement are curved to obtain proper purchase on the walls of the channel in which they toA choring lug receiving channels 33 to 36 inclusive.

ice

are secured. This enables the channels in which they are.

secured lo be moulded oversize thereby reducing breakage while maintaining proper interblade spacing and alignment.

Another object herein lies in the provision of structure of the class described wherein conductors of relatively large diameter may be accommodated, the outer cover of the conductor being substantially equal in size to thev interblade spacing, and wherein the exposed blades are supported close to their own axis.

Still another object herein lies in the provision of structure ofthe class described wherein the inner metallic parts thereof e.g. the connecting blades are completely and permanently insulated from the outer metal shell, so as to avoid all possibility of the same becoming charged at anyA time during the useful life of the same.

These objects and other incidental ends and advantages will more fully appear in the progress of this disclosure and be pointed out in the appended claims.

In the drawings, similar reference characters designate corresponding parts throughout the several views.

Figure l is a perspective view of an electrical connection plug showing a first embodiment of the invention. n

Figure 2 is an exploded perspective view of the plug Figure 5 is a view in perspective showing a pair of in' sulating plugs comprising a part of a second embodiment of the invention.

Figure 6 is a longitudinal sectional view as seen from the plane 6-6 on Figure 5.

' Figure 7 is a fragmentary sectional view corresponding-"i to that seen on Figure 3 showing the second embodiment of the invention. f

Figure 8 is a fragmentary sectional view corresponding to that seen on Figure 4showing the second embodiment of the invention.

Figure 9 is a plan view of an insulating plug comprising a part of a third embodiment of the invention.

Figure l0 is a fragmentary sectional view cor-responding to that seen on Figure 4 but showing the third embodiment of the invention.

Figure 1l is a fragmentary sectional view correspond4 ing to that seen on Figure 3, but showing the third embodiment of the invention.

ln accordance with the first embodiment of the invention, the electrical connection plug generally indicated by reference character 10 comprises broadly: a body element 12; a shell element 14;

blade elements

16 and 17; insulating plugs 18 and 19, and a strain relief element 20. The plug 10 may also include an insulating wafer 22, when desired.

As best seen on Figures 2, 3, 4, and 6, the body element 12 is preferably of generally oblong shape including front wall 24, rear wall 25, and

end walls

26 and 27, wall 28, and top wall 29, having a recess 30. The body 12 is preferably composed of a suitable insulating material having the requisite resistance to weather and temperature conditions. Suitable materials are synthetic resins of the phenolic, alkyd type, or polystyrene or lthe like. In view of the support produced by the shell element, relatively brittle materials may be used such as ceramics. The recess 30 provides the upper surface 31 and extending downwardly therefrom is the central cylindrical opening 32 through which the conductor may pass. Extending downwardly from said upper surface 31 are a plurality of an- The

channel

33 and 34 and the channel 35 and 36, at their Patented Dec. 1, 1959y 3 lower 'ends communicate with

pockets

37 and 33 respectively. Disposed outwardly of the opening 32 are a pair of screw shank receiving sockets. It is to be noted that the channels 33 to 36 inclusive are disposed between the open-l ing 32 (for the conductor) and the sockets 21 and 23.

The

blade elements

16 and 17 are substantially identical so that a detailed description of one will suffice for both. In order to avoid unnecessary repetition certain of the parts on the blade element 17 are given the same reference characters as the blade element 16 with the addition of the suffix a.

The blade element 16 is preferably formed from a planar piece of conductive material having the desired physical properties, as for example, preferably 1/2 to 3A hard brass .G64 inch thick. The blade element 16 includes a blade member d1, a base 42, upwardly directed corners 43, a threaded opening de, and a pair of downwardly extending anchoring lugs 47 and 48. The lugs 47 and 48 are generally parallel to the plane of the prong member.

The anchoring lugs are curved as best seen in Figures 2 and 5. While they are shown there as being curved in the direction of the base 42 they may be curved in the opposite direction.

By virtue of the shape and arrangement of the plug body element 12, there is a web 45 disposed between the

channel

33 and 34, and a corresponding web 46 disposed between the channel 35 and 36. The thickness of these webs from front to rear is substantially equal to the distance between the inwardly disposed surfaces of the

anchoring lugs

47 and 43. The length of the anchoring lugs 47 and 48 is each suliiciently greater than the vertical height of the web against which it is disposed in the assembled plug to provide terminals 52 and 53 which are swaged about the lower surface of the web d5.

As seen in Figures 3 and 4, binding screws 50 and 51 are engaged with the

bases

42 and 42a in a well-known manner for securing the terminals of the conductor.

As best seen in Figure 4, terminals 52 and 53 of the anchoring lugs l) and 5l are swaged toward each other about the lower surface of the web 15. This is preferably accomplished by pressing against a tool (not shown) having a. concave inner surface which curls the terminals toward each other so that they securely grip the web, thus preventing the removal of the blade element 16 from the plug body 12. The plug body itself serves as a guide to hold the anchoring lugs in such position as to properly receive the staking or swedging tool.

The shell element 14 is of generally cup shape having front and rear walls 54 and 55, end walls 56 and 57, and a bottom wall 58. The bottom wall 58 is provided with a central opening 59 through which the conductor may pass, and a pair of oblong holes 59 and 6d. The shell element 11i is maintained in place by crimping the upper edge 61, about the upper edge of the plug body element t 12. (See Fig. 3.)

The insulating plugs 13 and 19 are generally similar, each being wedge shaped and having a longitudinal trape- Zoidally configured cross section. The plugs are bounded by an inner surface 70, an outer surface 71, end surfaces 72 and converging surfaces 73 and 7d. The plugs are formed of any suitable non-conductive material which will match the electrical insulated properties of the plug body, while being able to adapt itself to the coniiguration of the channels in which it is disposed. Epoxy resins with a lightweight cellular filler have been found to be suitable, the same being employed as a putty like substance directly into the channels 33-36, or if desired, the plugs may be molded from synthetic resinous material such as Bakelite, silicone, rubber or the like. The plugs are imerted after the staking of the anchoring lugs 5@ and and prior to the assembly of the plug body element 12 within the shell element 14. The presence of the plugs 1S and 19 prevents the entry of dirt or other conductive material which may become lodged within the channels to prevent the possibility of charging the vshell element when the Adevice-s connected with an electrical outlet.

The strain relief element 20 includes a stationary member 62, and a movable member 63. The member 62 is of irregular configuration best seen in Figure 2, and it is of generally U-shape including a pair of tabs which are adapted to be inserted in holes 59land 60 of the shell element 14. The tabs.64 and 65are retained within the holes 59 and 60 by staking. The movable member 63 is provided with a pair of threaded orifices with which the screws 66 are adapted to engage. This permits the complementarily arranged curvedportions of the

members

62 and 63 to grip the conductor 11.

After the blade elements have been assembled upon the body element, this assembly is partially encased by the shell element 14.

With the electrical connection plug 10 in a fully assembled condition, it may be seen that the blade members 41 and 41a are maintained in a properly aligned spaced and parallel condition so that they may properly engage with standard receptacles. This alignment is assured byA the fact that the

bases

42 and 42a are perpendicular with respect to said blade members. The bases are maintained in contact with the upper surface 31 which is planar by the anchoring lugs 47 and 48 which are pulled down tight about the webs 45 (and 46).

in the normal manufacturing production of the

blade elements

16 and 17, the curvature of the anchoring lugs, assures Contact with the channel surfaces (see Fig. 3).

By virtue of the fact that the blade element is supported by two anchoring lugs which are substantially in the plane of the blade member, a very large opening for the passage of the conductor may be used (substantially of a diameter equal to the distance lbetween the blade ment-4 bers or larger). The blade elements are supported in the body element at 'a point Where the platform adds additional support to the blade rather than being in such a position as to increase the leverage by which the blade member may act as a lever to pull the anchoring lugs, out of the body element.

Turning now to the second embodiment of the invention, as illustrated on Figures 5, 6, 7'and 8, parts corresponding to those of the rst embodiment have been desig.

nated by similar reference characters with the additional. prefix 1.

The second embodiment of the invention differs from the rst embodiment in the provision in each insulating plug 11S and 119 of a pair of curved recesses of generally cup-shaped configuration. The anchoring lugs and.

151 are formed to be slightly longer in total length than. the corresponding lugs of the first embodiment, so that upon insertion of the plugs 118 and 119 a camming action.

results in the staking of the

terminals

152 and 153, respectively. By forming the

plugs

118 and 119 of toughand resilient synthetic resin, a slight blow on the outer surface of the plug easily stakes the terminals as indicated on. Figure 8. This eliminates the need for a separate staking. operation before the insertion of the insulating plugs as is necessary in the case of the first embodiment. In other respects, the second embodiment of the invention resem. bles the first embodiment.

Turning now to the third embodiment of the invention, parts corresponding to those of the first embodiment have been designated by similar reference characters with` the additional preX 2.

The third embodimenty of the invention consists in essence of future modification of the second embodiment, in which curved recesses St) and 81 in the

plugs

118 and 119 are provided with an overhanging portion 85 against which the staking action completed. This construction results not only in a self-staking operation as the plugs 213 and 219 are inserted, but in the employment of the stake portions to retain. the insulating plugs in position within the plug body.

Even though the channels. 33-36 may be slightly oversized to allow for irregularity4 I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modification will occur to the person skilled in the art.

I claim:

1. An electrical connection plug comprising: a body element having a pair of spaced channels, a blade element having a pair of anchoring lugs, said lugs being disposed one within each channel, said body having a wedgeshaped pocket therein communicating with said channels, said lugs being staked within said pockets, and a Wedgeshaped insulating plug Idisposed within said pocket and sealing said channels.

2. An electrical power connection plug comprising; a body element having a channel, a blade element having a blade member, a base and at least one anchoring lug, said lug being substantially in the plane of said blade member, said anchoring lug being disposed within said channel, and an insulating plug disposed Within and sealing said channel, said insulating plug having a curvilinear recess positioned to contact an end portion of said lug to stake the same against said channel.

3. Electrical power connection plug construction comprising: a body element having a plurality of channels; a blade element having a blade member, a base, and a plurality of anchoring lugs; said lugs being substantially in the plane of the blade member, and being disposed each within one of said channels; and an insulating plug disposed Within and sealing said channels, said insulating plug having a plurality of curvilinear recesses therein positioned to contact an end portion of each of said anchoring lugs to stake the same against said channel.

4. Electrical power connection plug construction comprising: a body element having a plurality of channels; a blade element having a blade member, a base, and a plurality of anchoring lugs thereon, said lugs being substantially in the plane of said blade member, and being disposed one Within each of said channels; and an insulati-ng plug disposed Within and sealing said channels, said insulating plug having at least one curvilinear recess therein bounded by an overhanging portion for each of said lugs, said recess being positioned to contact a portion of an anchoring lug to cam the same into contact with said overhanging portion whereby said insulating plug may be maintained within a channel in said body element.

References Cited in the tile of this patent UNITED STATES PATENTS