US2223231A - Connector plug - Google Patents

Description

Nov. 26, 1940. Q Q sMlTH "2,223,231

CONNECTOR 'PLUG Filed Sept. 10, 1937 Figi.

Patented Nov. 26, 1940 UNITED STATES coNNac'ron PLUG Charles C. Smith, Stratford, Conn., assignmto -General Electric Company, a corporation of New York Application september 1o, 1937, serial No. 133,281

1 Claim.

The present invention relates to connector plugs such as are used on cord lsets for connecting heating devices and the like to a current source.

In the manufacture of electrical connector plugs for relatively small currents, it is known to mold the contacts and adjacent portions of the conductor cord which is connected to the contacts in rubber, or the like, to provide a nonbreakable plug and a strain relief for the connections between the cord conductors and the contacts.

In the manufacture of connector plugs for larger electric currents, as in the case of atiron connector plugs, for example, this has not been possible because of the high temperature which the contacts may reach during operation, temperatures of the order of 600 F. being met with sometimes.

One object of the present invention is to provide an improved plug structure wherein the connections between the cord conductors and the contacts are molded in rubber, or the like,`

to provide a strain relief and which avoids dif- 'lculties in so far as the highl temperatures met with are concerned.

A further object of the invention is to provide a plug structure wherein the cord is firmly anchored in the plug body so that any pull on the l cord is taken by the body of the plug.

A further object of the invention is to provide an improved construction of plug contact which is simple to manufacture and to which the conductor is connected without'the use of screws.

Further objects and the advantages of the invention are pointed out in the following speciiication.

In the drawing, Fig. 1 is a top View of a plug embodying the invention, a portion of the plug body being broken away; Fig. 2 is a top view of a connector plug with the upper half of the plug body removed; Fig. 3 is a. longitudinal sectional view of the plug; Fig. 4 is a perspective View of one of the plug contacts, and Fig. 5 is a top view of the two contacts with the strain relief member molded thereon. y

Referring tothe drawing, the plug comprises a vplug body or housing formed of two complementary halves 6 and 'l fastened together by a suitable means, such as rivets 8. The plug body is formed from a suitable molding compound, such as a phenolic condensation product or other resinous substance and a suitable filler, capable of withstanding the temperatures met with. It may be formed from any of the molding compounds now in use for connector plugs of this type. The plug body is provided with a longitudinally extending partition 9 which divides the interior of the body into two longitudinally extending passages I and Il. The par- 5 titionwall 9 terminates short of the rear end of the plug body and at this point the plug, body is enlarged somewhat to provide a pocket I2. At the inner end of the pocket I2 are shoulders I3. The longitudinal wall 9 is formed preferably with 10 a part integral with each of the plug bodyhalves, the line of demarkation between the parts being indicated at I4 in Fig. 3. In the rear end of the plug body isan opening I which communicates Y with the pocket I2. In the fron't wall of the l5 plug are openings I6 for the admission of contact posts or blades. f

Located in the passages I0 and Il are contacts I'I. Referring particularly to Fig. 4, each contact comprises a clamping endI or socket I8 and 20 arelatively long shank I9 of relatively limited cross-sectional area to the outer end of which the conductors'of the electric cord are connected. The walls forming the socket are curved outwardlyas indicated at to provide for the 25 admission of contact parts or blades between lthem and each is provided. at its central portionwith a struck out spring tongue 2l which grips a contact post inserted between them. The contact is formed preferably of two strips which are substantially alike except that onev strip is provided with the relatively long extension I9 and the two strips are fastened together by suitable means as` by riveting, as indicated at 22. The outer end of the extension I9 has its walls 35 bent around to provide a tapered pocket 23 for the reception of the end of an electric wire.

An electric cord 2t having two conductor wires 25 is indicated in the drawing. The ends of the conductor wires arevconnected one to each of the contacts Ii. This may be done by inserting the end of the wire in the tapered pocket 23 and fixing it in place by means of solder as indicated at 26; or after the wire is in place, the walls of the pocket may be squeezed down around the 45 wire by the use of a suitable tool. After the two conductors have been connected to the two contacts, the two contacts are assembled in correct spaced relation to each other in a suitable x-v ture and a body 21 of suitable insulating mate- 50 rial, such as rubber or the like, is molded directly around the outer ends of the extensions I9, the ends of the conductors 2i, and the adjacent portion of the cord 2l. This serves to anchor the connections between the conductors and contacts l in the insulating body 21 and also to provide a strain relief for the connections. Body 21 is of a size and shape to it in pocket I2 and it will be clear that any pull on the cord 24 will be taken by the body 21 engaging the wall of the pocket. The body 21 at its inner end' ts against the shoulders I3 and is held against'the shoulders by the tapered walls of the pocket as indicated at 29. Preferably the adjacent portion of the cord 24 has material molded around it for quite some length as indicated at 30,- thus providing protection against sharp bending of the cord where it enters the body, also it is preferably provided Witha bead or ange 3l which engages the outer rear face of the. plug body. To hold the contacts from longitudinal movement in passages I and II, body halves 8 and 1 are provided with abutments 32 with which `the innerl ends of tongues 2| engage. y

In use, as pointed out above, a connector plug of this type is subjected often to fairly high temperature, the contact sockets I8 reaching some times temperatures of the order' of 600 F. This `is a temperature higher than rubber or similar by molded body 21, the two body members 6' and 1 can be permanently fastened together by rivets.

This is of advantage in that the fastening tol0 gether can be done at low cost, and being permanently fastened together, the plug cannot be tampered with. The sockets I8 of theV contacts fit loosely in the passages III and II so that they can float to a limited extent to permit of connecl tion to posts or contact blades which may be somewhat out of alignment.

What I claim as new and desire to secure by Letters Patent of the United States is:

A connector plug comprising a housing formed of an insulating material capable of withstanding relatively high temperatures and having twoy spaced longitudinally extending passages and a pocket With which the rear ends of said passages communicate, contact sockets in the forward ends of said passages, said sockets being provided with elongated Shanksv of relatively limited cross-sectional area extending from the socket through the passages to said pocket, an electric cord having its conductors connected to the ends of said 3G Shanks and resilient insulating material surrounding and embedding the ends of said Shanks and the connections of the conductors therewith and forming a body which fits in said pocket and is held in position by said housing, said insulating material extending a distance back from said housing and surrounding said cord to form a strain relief sleeve, said shanks dissipating the heat from said contacts incidentto connection of the plug to a heating appliance to protect said body of insulating material from damage due to the effect of the heat. CHARLES C. S 1

Since the connec- 5 tion between the conductors andthe contactsism n a permanent one and protected from breakage"

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