US2712121A

US2712121A - Schmier

Info

Publication number: US2712121A
Authority: US
Publication date: 1955-06-28
Anticipated expiration: 1972-06-28

Description

June 28, 1955 J. SCHMIER MULTIPLE OUTLET ELECTRIC CONNECTOR WITH SECURING MEANS FOR A LINE CORD Filed June 22, 1950 lhwentor Jusuh Schmier.

United tates Patent MULTIPLE OUTLET ELECTRIC CONNECTOR WITH SECURING MEANS FOR A LlNE CORD Jacob Schniier, Allentown, Pa., assignor to Rodale Manufacturing $0., Inc., Emmaus, Pa., a corporation of Pennsylvania Application June 22, 1950, Serial No. 169,620

2 Claims. (Cl. 339-157) My invention relates to a service block or an electrical junction or plug-in connector which provides branch electrical circuits.

Heretofore, junction or cube-taps for service blocks have been used to a great extent, these service blocks usually consist of a plug at one end of a two-wire conductor. The transmission conductors have to be looped or tied together within the chamber of the tap so that any mechanical force exerted upon the wires will not break the electrical contact from the terminals within the Q-tap. The underwriters usually require that a knot between the insulated wires be tied within the chamber so that a pull upon the wires would not break the bare wire from its terminal. The problem with the knot has been one of space. The underwriters provide further that the knot be a Q-shaped knot which is a particular type of knot.

It, therefore, is an object of my invention to provide a having the lead-in wires connected to each terminal with a screw.

Fig. 7 is a front view of one of the terminals shown in Fig. 6.

Referring now in detail to the drawing wherein similar reference characters refer to similar parts, I show a multiple plug convenience receptable, cube taps or service plug, generally designated as A, to which a pair of insulated electrical conductors, cords, or wires, generally designated as B, are permanently connected. The conductors B have at their free end a plug (not shown) which is connected to a source of electricity such as a 120 volt line. The multiple plug receptacle A receives a plurality of plugs 10 which supply power to other electrical devices (not shown) such as electrical lamps, clocks, radios, television sets, etc.

welded or soldered connection from the main conductor 5 Another object of my invention is to provide a terminal for a service block wherein a single press operation The casing for the plug A is made of Bakelite or other suitable synthetic resin and comprises two identical shells, C1 and C2, which are fitted together.

Each shell of the casing has a hollow interior defined by a bottom 12 and a discontinuous wall 14 protruding from the edge of the bottom 12. At one side of the wall 14 is an opening 16 through which the insulated cord B passes. Substantially in line with the opening 16 on the other side of the wall 14 are two spaced openings 18 and 20 in order to admit the penetration of plug terminals (not shown) from the plug 10. Between the openings 18 and 20 is a projection 22 which has a pair of

right angle sides

24, 26 within the hollow interior. The bottom of the shell C1 has a vertical projection 28 integrally molded therewith with a central bore 30 therethrough. A pair of thin parallel ridges 32, 34 join the vertical projection 28, the bottom 12 and the wall 14 as a continuous integral member of the shell. Within the wall 14 and through the bottom 12 are a pair of spaced

openings

36, 38 for the purpose of permitting electrical conducting pins (not shown) on the plug 10 to pass therethrough. The wall 14 is provided with a pair of

parallel grooves

40, 42 perpendicular to the bottom 12, one groove falling on one side of the opening 16 and the other groove falling on the other side of the opening 16. The shells C1 and C2 are converse of each other, that is to say, when they are placed enables the terminal to be pressed down so each arm is independently resilient.

Other objects of my invention are to provide an improved service block, which is easily and economically produced, sturdy in construction, and which is highly efiicient in operation.

With the above and related objects in view, my invention consists in the details of construction and combination of parts as will be more fully understood when the following description is read in conjunction with the accompanying drawing, in which:

Fig. 1 is a side view of a multiple contact service block.

Fig. 2 is a front view of the multiple contact service block showing the openings for the plug of an auxiliary circuit.

Fig. 3 is a front view of one-half of a multiple contact service block with the terminals in position showing one Wire of the incoming leads connected to the top edge of 'one terminal and the other wire of the incoming leads connected with the opposite terminal in order to separate the wires.

Fig. 4 is a front view of the complementary half of the casing for the service block.

Fig. 5 is a front view of a terminal embodying my invention.

Fig. 6 is a side view of a pair of modified terminals independent of each other.

together the opening 20 in shell C1 coincides with the opening 18 of shell C2 and groove 40 of shell C1 coincides with groove 42 of C2 etc.

An electrical contact or terminal, generally designated as D, illustrated in Fig. 5 is of generally cross-shaped configuration. The

flexible contact arms

44 and 46 are utilized to electrically engage terminals inserted into the

openings

36 and 18 of the service block shell C1, and the flexible contact arm 48 is contacted by a plug terminal through the opening 38 in the shell C2.

The junction of the

flexible contact arms

44, 46 and 48 is provided with a bore 50 to make each arm flexibly Small punched projections 52 near the base of the

arms

44, 46 and 48 interact with the hole in a plug terminal to prevent the male plug from being easily pulled out after it has been inserted into my service block. The ends of the

arms

44, 46 and 48 are all bent at an angle and in the same direction to nestle within a portion of the shell in order to brace the ends of each arm whereby the flexing of the contact occurs near its center.

In order to economize in space and in order to provide a suitable holding member for one wire of the insulated conductor B, the contact D is provided witha relatively thin and wide projecting portion 54 which has a recess in its side 54A to receive the thickness of the insulated wire. The projecting portion 54 also serves as a connecting point for a bared portion of the electrical conductor. The insulated wire comes in from one end alongside the thin shell wall .14 and passes through the recess 54A from one side of the projecting portion 54 and the end of the wire has the insulation removed therefrom so that the bare wire may be welded or soldered, or held by a screw 56 as illustrated in Figs. 6 and 7 which is threadedly engaged with the projecting portion 54 opposite the recess 54A.

A larger punched projection 58 is provided in the pro jecting portion 54 adjacent the screw 56. The bare Wire is wrapped around the screw 56 and between said projection 58 to prevent the wire from slipping out while turned under the screw 56.

In this manner a pull on the outside of the cord or wire will exert a tension on the insulation within the recess 54A of the projecting portion 54 rather than directly upon the electrical conductor itself. Hence, any strain upon the wire will be relieved by the insulation. It should be observed that on one terminal D the wire goes through the recess 54A on the top of the terminal D and on the other terminal D the wire goes through the recess 54A on the bottom of the terminal separating the incoming conductors widely within the casing A.

The

recesses

54B and 54C located near the arms -44 and 48, respectively, are provided to allow the arms to be free of the projection 54, otherwise the arms would be firmly attached to the projection 54 and not be flexible toward the center portion of the contact D.

A pair of small ridges 55A and SSE at right angles to the projection 54 are provided near the sides and at the bottom edge of the projection 54 to keep the projection 54 i from moving within the

grooves

40 and 42, thus, preventing the contacts from getting out of alignment, which in turn would prevent the insertion of a terminal plug to engage with said arms of said contact.

It is readily apparent that the contact D may be manufactured easily and economically by the utilization of a suitable punch and die whereby the arms would be bent, the bore punched, the said recesses also punched, as well as the small ridges and the punched projections hereinbefore mentioned would be formed at a single operation.

The service block is easily assembled from the shell and contact described in the following manner:

Each lead of the two-wire conductor B is soldered and fastened to a contact D in the manner described. One contact D is then inserted in the shell with its projection 54 in the groove 40 and the bent portion of the arm 46 against the right-angled side 24 of the projection 22. The other contact D is then inserted in the same shell with its projection 54 in the groove 42 and the bent portion of the arm 46 against the right-angled side 26 of the projection 22. By placing the contacts D thusly in the shell the separate wires are widely separated as one wire goes around one contact D in one direction while the other wire goes around the other contact D in the opposite direction. The obverse shell is then placed over the shell containing the contacts D and the two are bound or fastened together by a screw or rivet through the bores 30 of the shells.

It is readily apparent that this method of mounting the contacts D leaves them free-floating within the shells C1 and C2 with the projecting portion 54 within the

grooves

40 and 42 preventing thorn from twisting under pressure from penetration of plug terminals (not shown) of plug 10. The contacts D are held from moving upwardly by the thin parallel ridges 32 and 34. Resiliency is provided in the arms by the bent over portions of same bearing against the vertical projection 28 and the projection 22 within the hollow interior 12.

It is important to bear in mind that the contact D illustrated in Figs. 6 and 7 is of the same construction and utilized in the same manner, except that it is provided with a screw therethrough to secure the bared end of the conductor.

From the foregoing description, it is apparent that my 4 improved service block is easily and quickly assembled, easily and economically manufactured, and insures against the pulling out of the wires because the conductors are looped around the terminals with the strain of a pull being taken up by the insulation of the wire within the recesses provided therefor. It is also apparent that the contacts D cannot twist or turn in the service block and yet are free and resilient.

Although my invention has been described in considerable detail, such description is intended as merely illustrative, rather than limiting, as my invention may be variously embodied, and the scope of the invention is to be determined as claimed.

I claim as my invention:

1. An electrical service block comprising a housing having walls defining a chamber, an opening in one of said walls in said housing to receive an electrical conductor,

' a pair of internal grooves in one of said walls adjacent said opening, one of said grooves being positioned at one side of said conductor opening and the other of said grooves being positioned at the opposite side of said opening, an internal projection on another of said walls having two right angle corners at its end and being located independently flexible, said contact member also having a thin and wide extension thereon whereby an electric wire may be attached to said relatively thin and wide extension, said extension having a recess in its sides to receive the thickness of an insulated wire, a pair of said electrical members within said chamber, said contact members being positioned in spaced and parallel relationship with each other, each of said contact members being provided with ridge portions at opposite ends, one of said terminal members having one of its ridge portions seated in one of said grooves in said chamber and its other end portion seated in one of the corners of said projection, and the other of said contact members having its ridge seated in the second groove in said housing and its other end portion seated in the second corner of said projection, two other pairs of spaced openings formed in the walls of said housing, and said contact arms extending toward said openings in said walls whereby the contact members of additional male plugs may be electrically connected to said contact arms.

2. An electrical contact member for a plug-in connector comprising a substantially single flat-like contact member having a plurality of contact arms radiating at right angles from its center and each arm being independently flexible, a thin and wide extension at one end of said contact member having a recess in its sides to receive the thickness of an insulated wire whereby strain on said wire will be relieved when a pull is imposed on said wire, and said wire is attached to said extension, a pair of slots on each side of said extension and aligned with one another to space two of said contact arms from said extension and an opening through the center of said flat-like contact member to provide greater flexibility of said contact arms, and said contact arms being independently flexible of one another.

References Cited in the file of this patent UNITED STATES PATENTS 873,872 Krantz Dec. 17, 1907 1,941,489 Propp Jan. 2, 1934 2,092,527 Chirelstein Sept. 7, 1937 2,210,215 Herman Aug. 6, 1940 2,318,484 Herman May 4, 1943 2,371,494 Benander Mar. 13, 1945 2,446,709 Ludwig Aug. 10, 1948