US3783438A

US3783438A - Electric wall plug

Info

Publication number: US3783438A
Application number: US00257115A
Authority: US
Inventors: P Grant
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-26
Filing date: 1972-05-26
Publication date: 1974-01-01
Anticipated expiration: 1991-01-01

Abstract

An electric wall plug having a sleeve or insert member maintaining the contact ends of the flexible prongs in secure engagement with the ends of the connector wires without any need for wrapping the wires around the contact ends. This permits rapid assembly and disassembly of the plug.

Description

United States Patent [191 Grant 1 ELECTRIC WALL PLUG [76] Inventor: Philippe G. Grant, PO. Box 1076,

Station B, Ottawa, Ontario, Canada 22 Filed: May 26,1972

2] App1.No.:257,11S

[52] U.S. Cl. 339/196 R, 339/210 R [51] Int. Cl H0lr 33/06 [58] Field of Search 339/63, 97 R, 98,

339/99, 107, 196, 206, 208, 210, 17 F, 176 MP, 195 R, 195 M [56] References Cited UNITED STATES PATENTS 2,032,470 3/1936 Chirelstein 339/63 R 2,042,580 6/1936 Bernfeld 339/63 R 1,988,725 1/1935 Glade 339/196 R X Jan. 1, 1974 1,956,018 4/1934 Gilbert 339/99 R 2,196,052 4/1940 Benander 339/63 R FOREIGN PATENTS OR APPLICATIONS 72,541 5/1951 Denmark 339/196 R 882,872 7/1953 Germany 339/195 R Primary ExaminerMarvin A. Champion Assistant Examiner-Lawrence J. Staab Attorney-A. J. S. Davidson et a1.

[57] ABSTRACT An electric wall plug having a sleeve or insert member maintaining the contact ends of the flexible prongs in secure engagement with the ends of the connector wires without any need for wrapping the wires around the contact ends. This permits rapid assembly and disassembly of the plug.

2 Claims, 8 Drawing Figures ELECTRIC WALL PLUG This invention relates to an electrical outlet plug and, particularly, to a plug which is easily assembled and dis assembled and makes a secure and positive electrical contact.

A problem well known to the householder is that of an electric wall plug where the connecting wire has been broken due to being placed under too large a tension while the plug is removed from an outlet receptacle. This occurs when pressure is applied to the wire rather than the body of the plug. Alternatively, the wire attached to the plug may require shortening or lengthening. It then becomes necessary either to repair or replace the wire and even the plug. Some plugs are formed in such a manner that when the wire is broken adjacent the plug, repair is impossible and the whole unit must be replaced. In other types of plugs, the wire conductors are placed in electrical contact with the prongs by means of screws. The wires must, firstly, be bent around the shank of the screw, and, secondly the screw must be screwed in to tightly engage the wire and force it against the prong. To keep the inside diameter of the bend of the wire in close proximity with the shank of the screw often presents a problem and quite often a poor and dangerous connection is made.

It is the intention of this invention to eliminate these problems and this is accomplished by providing an electrical wall plug of novel and simplified construction, thus offering advantages to both manufacturer and user. Preferred embodiments of the invention will now be described in conjunction with the drawings in which: I

FIG. 1 is a perspective view, partially in section, of one embodiment of the invention;

FIG. 2 is a view, in cross-section, of the same embodiment;

FIG. 3 is a view, in cross-section, of an alternative embodiment;

FIGS. 4 and S are views of yet another embodiment;

FIG. 6 is a cross-sectional view of a further embodiment; and

FIGS. 7 and 8 are views ofa still further embodiment.

Reference will now be made to FIGS 1 and 2. The electrical wall plug 10 consistsessentially of a body member 11, a pressure applying sleeve 12, a pair of

resilient prongs

13, 13 and two wire electrical conductors The body member 11 includes a base portion 15 and a central portion 16 which extends from and is integral with the base portion. The top surface of the base portion, as viewed in FIGS. 1 and 2 forms a shoulder 17. Within the base portion 15, two passageways l8 and 19 are formed through which the wire 14 extends. The passageways are joined at one end. The other ends open in shoulder 17 as illustrated. A recess 22 is formed on both sides 23 of the central portion 16. The recess locates and accommodates the prong 13 during assembly of the plug.

The prongs 13 are fastened to the central portion of the body member by means of screws or rivets 25 which extend through a hole appropriately formed in end 27 of the prongs. It will be appreciated that the use of screws is not essential to the successful operation of this invention. Any of a number of methods may be used to fasten the prongsto the body member. The other end 28 of each prong is formed with an inwardly directed protuberance 29 adapted to cooperate with grooves 30 formed in the central portion 16. The bared ends of thewires are positioned in these grooves.

The pressure applying sleeve 12 is formed with an opening or cavity 32 to'receive the central portion of the body member I]. The lower end of the sleeve abuts shoulder 17 and its upper end is flush with the upper surface of the body member 11, as illustrated in FIGS. 1 and 2.

To assemble the plug becomes a simple matter. The prongs 13 are positioned in recesses 22 and fastened thereto by means of screws or rivets 25. A length of the wire 14 is bared and passed through passageways 18 and 19 a sufficient distance so that the ends thereof may be positioned between protuberances 29 and grooves 30. The prongs are pressed inwardly with the fingers and the sleeve 12 is then positioned over the prongs and pressed towards the base portion 15 until one end of the sleeve engages shoulder 17. As the sleeve is moved over the prongs, it will become apparent that the prongs are kept pressed inwardly, thereby securing the wire between the end 28 of the prong and the sides of the central portion 16 of the body member.

The embodiment just described discloses a plug which is rectangular in cross section. It will be appreciated that, without departure from the spirit of the invention, the plugs could be circular or any other de' sired configuration incross section. Similarly any number of prongs could be provided without departing from the scope of the invention.

FIG. 3 shows a slightly different embodiment than that of FIGS. 1 and 2. FIG. 3 shows a plug 40 having a body member 41 and, instead of a sleeve, an insert 42. The body member 41 is formed with a cavity 45. A pair of recesses 52 are provided in the body member to locate the prongs 43. In a manner similar to that of the previous embodiment, the prongs may be fastened to the body member by means of screws or rivets 55, at the ends 57 thereof. Ends 58 of the prongs are curved forming outward protuberances 59. The insert 42 is preferably solid and has dimensions which closely approximate those of the cavity 45.

It can be seen, therefore, that when the wires are placed between the protuberances 59 and the walls of the cavity and the insert is press-ed into position, the prong will apply an outward force to the wire thereby securing them in position and providing a positive contact for the flow of current.

FIGS. 4 and 5 show another embodiment of the present invention. The electrical outlet plug consists of a pressure invention. The electrical outlet plug consists of a pressure applying member and a main body member 72. For clarity FIG. 4 shows the pressure applying member 70, partially in section, removed upwardly from the body member and rotated so that the internal details can be more easily seen.

The body member 72 is formed with a main wall 74 and an abutment or lower lip 75. A block 76 extends from wall 74. A pair of contacts 77 are securely fastened to the block adjacent wall 74. An end 79 of each contact is formed with a protuberance 80. The block is formed with recesses 82 which cooperate with the protuberances to retain the ends of wires 83 and 84 when the pressure applying member 70 is in engagement with the body member 72. The wires extend through an opening 85 formed in the abutment 75. It will be noted that a space is provided between the block 76 and the abutment 75 in order that the wires may be easily inserted in position. In an alternative embodiment opening 85 can be provided on the line of junction of abutment 75 and the side wall of member 70, by forming cooperating semi-circular openings in each member.

The pressure applying member 70 has a lip 90, outer abutments 91 and an inner wall 92. A pair of

side walls

93 and 94 together with walls 92 define a cavity in member 72.

Formed integrally with

side walls

93 and 94 are

tongues

97 and 98. A similar tongue 99 is formed in the lower surface of lip 90.

Tongues

97, 98 and 99 cooperate with

grooves

100, 101 and 102 respectively formed in block 76 of body member 72. A fourth tongue 106 formed integrally with wall 92 cooperates with a corresponding groove 105 is formed in block 76. Lip 90 includes a pair of

openings

103 and 104 through which the contacts 77 extend.

The assembly of the electric wall plug will now be described. The contacts 77 are first fastened to the block 76 of body member 72 by means of screws or rivets.

The ends of the wires 83 and 84 are bared, passed through opening 85 and positioned between the block 76 and the ends 80 of the prongs 77. Prongs 77 are pressed inwardly by the fingers to retain the wires in position. The pressure applying member 70 is then positioned in such a manner that the contacts extend through

openings

103 and 104 and

tongues

97 and 98 are aligned with

grooves

100 and 101, respectively. The pressure member 72 is then moved downwardly until the lower surface thereof contacts abutment 75. At this time tongue 106 engages groove 105 and, thereby, relative axial movement between body member 72 and pressure member 70 is prevented. Separation of

members

70 and 72 is prevented by means of engagement between

tongues

97, 98 and 99, and

grooves

100, 101, and 102, respectively.

FIG. 6 shows an alternative embodiment in which the plug end of the resilient prong 120 is formed with an inwardly curved portion 124 notched to receive the wire end 125. Body portion 123 is formed with a cooperating recess 128 and, after assembly, sleeve member 127 maintains the prong in secure contact with the wire. It will be noted that prong 120 is a flat strip, not doubled back on itself, held to body portion 123 by screws or rivets 122.

A still further embodiment is shown in FIGS. 7 and 8. Resilient prongs 103 are each formed from a flat piece of metal having a bend at 131 so that the half sections occupy planes at right angles to one another. Section 132 also includes additional corrugations forming a pair of inwardly directed protuberances. The plug housing comprises cooperating lower and

upper sections

135 and 136 which are formed with grooves having surfaces conforming to the corrugations in each contact section 132. In the assembled condition the bared ends of wires 137 are positioned against the protuberances in contact sections 132 and maintained in that position by housing 134, its upper and lower sections being held together by suitable means such as screws 138.

I claim:

1. An electrical plug comprising in combination a body member and a sleeve-type pressure applying member of complementary form,

said body member being formed with a substantially planar wall, a lower lip at one end thereof and a block centrally located on the wall having a pair of shallow recesses for receiving the ends of electrical conductors in substantially linear configuration,

a pair of V-shaped resilient prongs secured one on each side of said block, each prong having a protuberance registering with the corresponding recess in the block,

said pressure applying member being formed by a pair of spaced abutments connected together by an upper lip and substantially planar rear wall to define a central cavity,

said block being formed with a pair of grooves extending in the direction of said prongs and said abutments having cooperating tongues whereby said body member and said pressure applying member fit together by sliding action with said planar walls defining the outside surface of said plug, said spaced abutments urging said protuberances against the ends of the corresponding conductors towards the recesses to form secure electrical contact.

2. An electrical plug as defined in claim 1 wherein said block is formed with a further groove extending at right angles to the direction ofthe prongs and said pressure applying member has a further tongue cooperating with said further groove to maintain the plug in its assembled condition.

Claims

1. An electrical plug comprising in combination a body member and a sleeve-type pressure applying member of complementary form, said body member being formed with a substantially planar wall, a lower lip at one end thereof and a block centrally located on the wall having a pair of shallow recesses for receiving the ends of electrical conductors in substantially linear configuration, a pair of V-shaped resilient prongs secured one on each side of said block, each prong having a protuberance registering with the corresponding recess in the block, said pressure applying member being formed by a pair of spaced abutments connected together by an upper lip and substantially planar rear wall to define a central cavity, said block being formed with a pair of grooves extending in the direction of said prongs and said abutments having cooperating tongues whereby said body member and said pressure applying member fit together by sliding action with said planar walls defining the outside surface of said plug, said spaced abutments urging said protuberances against the ends of the corresponding conductors towards the recesses to form secure electrical contact.

2. An electrical plug as defined in claim 1 wherein said block is formed with a further groove extending at right angles to the direction of the prongs and said pressure applying member has a further tOngue cooperating with said further groove to maintain the plug in its assembled condition.