US3444618A - Method of forming electrical elements - Google Patents

Description

0, 1969 N. L. SQRLIE 3,444,618

METHOD OF FORMING ELECTRICAL ELEMENTS Filed Sept. 23, 1965 Sheet of 2 May 20, 1969 N. a... SORLIE mmnou OF FORMING ELECTRICAL ELEMENTS Filed Sept. 23, 1965 United States Patent ABSTRAQT OF THE DISCLOSURE A method of forming an electrical male plug whereby the terminals are spaced apart by an integral strlp both before and after the terminals are placed in a mold and which is removed during the plug-molding process.

This invention relates to electrical apparatus and in particular to electrical connectors.

In one form of electrical connector, a pair of terminal blades are mounted in a body formed of insulating material so as to project outwardly therefrom and define a pair of spaced electrical male terminals suitable for insertion into a corresponding female connector member such as a wall outlet. The terminals are connected to suitable electrical conductive wires within the insulating body for conducting current from the terminals through the wires. Such an electrical connector is conventionally called a p Ii the manufacture of such electrical plugs, it is necessary to accurately space the terminals so as to preclude short circuiting therebetween and to arrange the outwardly projecting portions in accurate spaced alignment to be received in the conventional female socket. It has been conventional to obtain this desired accurate disposition of the terminals in the plug body by forming the terminals as separate elements, connecting them to the end of the wires and then either providing means for accurately positioning the terminals in a molding device for molding the plug body therearound while the terminals are so held, or inserting the terminals in suitable recesses in preformed molded plug bodies. These conventional methods of forming such plugs have the serious disadvantage relatively high cost. The present invention is directed to the forming of such electrical plugs in a new and improved manner substantially reducing the cost thereof, while yet providing the highly desirable accurate spaced disposition of the terminals in the plug body.

Thus, a principal feature of the present invention is the provision of a new and improved method of forming an electrical plug.

Another feature of the invention is the provision of such a method wherein the terminals are formed with a connecting portion which accurately spaces the terminals during the forming of the plug, with the connecting portion being suitably severed during the forming of the plug body to provide suitable electrical clearance between the terminals in the finished plug.

A further feature of the invention is the provision of such a method wherein the connecting portion is disposed within the plug body.

A yet further feature of the invention is the provision of such a method wherein the connecting portion is disposed externally of the plug body.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a transverse section of an electrical plug formed by a method embodying the invention;

FIGURE 2 is a plan view of a terminal blank for use in the plug;

FIGURE 3 is a side elevation of the further formed terminals;

FIGURE 4 is a vertical section of a molding apparatus with the partially formed terminals of FIGURE 3 having suitable electrical wires connected thereto and installed in the molding cavity;

FIGURE 5 is a vertical section similar to FIGURE 4 but with the mold dies brought together and with a shearing portion of the mold actuated to sever the connecting portion between the terminals;

FIGURE 6 is a fragmentary vertical section taken substantially along the line 66 of FIGURE 5;

FIGURE 7 is a fragmentary vertical section similar to that of FIGURE 6, but with the shearing means retracted;

FIGURE 8 is a transverse section of another form of electrical plug formed by a method embodying the invention;

FIGURE 9 is a plan view of a terminal blank for use in the plug of FIGURE 8;

FIGURE 10 is a side elevation of the further formed terminals;

FIGURE 11 is a perspective view of a molding means suitable for use in forming the plug of FIGURE 8;

FIGURE 12 is a vertical section of another form of molding apparatus with the partially formed terminals of FIGURE 10 having suitable electrical wires connected thereto and installed in the molding cavity; and

FIGURE 13 is a vertical section similar to FIGURE 12 but with the mold dies brought together and with a shearing portion of the mold disposed to sever the connecting portion between the terminals.

In the exemplary embodiment of the invention as disclosed in FIGURES 1 through 7 of the drawing, a plug generally designated 10 is shown to comprise a pair of terminals 11 retained in an insulating plug body 12 with the wire ends 13 of a suitable electrical conductor 14 connected to the terminals by suitable means such as solder 15. The terminals include outer male portions 16 arranged in accurate spaced relationship for insertion into a suitable female connector (not shown) in the conventional manner. The invention herein disclosed and claimed lies in the improved method of forming the plug 10 with the terminals 11 in the illustrated accurately spaced relationship.

More specifically, the terminals 11 may be stamped from suitable electrically conductive sheet material to form a blank 17 as shown in FIGURE 2 including a connecting portion 18 bridging the terminal portions 19 adjacent one end thereof provided with a plurality of formed tangs 20. It should be understood that the end adjacent portion 18 may be formed to accommodate tubular terminals. The blank 17 is formed as shown in FIGURE 3 to define the male portions 16 terminating in a turned distal end 21. The bared ends 13 of the wire conductor 14 are connected one each to the terminals 16 by folding over the tanks 20 and by crimp 15, as shown in FIGURE 4. The terminals are installed in a suitable mold means member 22, as shown in FIGURE 4, with connecting portion 18 serving to accurately dispose the terminals in spaced relationship within the mold means member. An upper mold means member 23 is provided for cooperation with lower mold means member 22 to form a mold cavity 24, as shown in FIGURE 5, when the mold members are brought together. The movement of the mold members from the open position of FIGURE 4 to the closed position of FIGURE 5 may be effected by suitable conventional means such as piston means 25 shown fragmentarily in FIGURE 4. The insulating material of which the plug body 12 is formed may be supplied from a conventional supply S through a suitable supply conduit 26 having communication with the molding chamber 24 through an inlet passage 27.

As indicated briefly above, the invention comprehends the severing of the connecting portion 18 substantially concurrently with the molding operation, whereby th 3 terminals 11 are electrically separated in the final plug structure 10, while yet are disposed in accurate spaced relationship within the mold cavities by arrangement thereof as an integral joined assembly when inserted into the cavity. The concurrent molding and severing operations are illustrated in FIGURES 5 through 7. More specifically, the mold members carry a pair of cooperating shearing members 28 and 29 which move into the cavity 24 and retract therefrom substantially concurrently with the molding operation. Thus, as shown in FIGURE 6, the upper shearing member 28 moves downwardly into the cavity 24 to engage the connecting portion 18 and sever it from one of the terminals 11, the connecting portion 18 being supported from below by the lower shearing member 29 which as shown in FIGURE 6 moves upwardly to provide a suitable crimp in the connecting member to facilitate the separation operation. As shown in FIGURE 7, the severing operation is completed by the retraction of the shearing members 28 and 29 to an arrangement fiush with the walls of the die members 22 and 23, whereupon the plug portion 12 is formed about the terminals 11 with the space between the severed connecting portion 18 and the terminal 11 from which it was cut being filled by solidifying the insulating material of the plug body 12.

As shown in FIGURE 1, the turned end 21 of the terminals 11 is embedded within the plug body 12 to effec tively lock the projecting portion 16 against movement relative to the plug body as by frictional forces acting thereagainst during insertion or withdrawal thereof relative to the female connector. The remaining portion of the connecting member 18 augments this retaining action as it also is embedded in the plug body in the resultant plug, as shown in FIGURE 1. Still further, as shown in FIGURE 1, the connecting member 18 serves to maintain the spaced relationship between the male terminal portion 16 by reinforcing the plug portion between the terminals.

Turning now to the embodiment of FIGURES 8 through 13, a modified form of plug 110 is shown to comprise a plug generally similar to plug but having terminals 111 wherein the connecting portion 118 is disposed eXteriorly of the plug body 112 during the forming operation. In describing the embodiment of the invention illustrated in FIGURES 8 through 13 similar reference numerals, but one hundred higher, will be employed for elements corresponding to the elements of the embodiment of FIGURES 1 through 7.

More specifically, the terminals 111 may be formed from the modified blank 117 wherein the connecting portion 118 is spaced from the tank end 120'. Thus, when the blank is bent to form the preformed assembly of FIGURE 10, the connecting portion 118 is disposed between the outer male elements 116. As shown in FIGURE 11, the lower die member 122 is provided with a recess 130 adapted to receive the preformed terminal assembly of FIGURE 10. The upper die member 123 is provided with a corresponding recess 131 and a depending shearing member 128 adapted to shear the connecting portion 118 from the terminals 111 and pass the removed section 132 outwardly through an opening 133 in the lower die member 12. Thus, the shearing of the connecting portion 118 from the terminals 111 is effected substantially concurrently with the introduction of insulating material from the supply conduit 126 into the mold chamber 124. In all other respects the method of forming plug 110 is similar to the method of forming plug 10 as described above.

Thus, the invention comprehends an improved method of forming an electrical plug wherein the terminals are maintained in accurate spaced relationship for facilitated clearance between the terminals is effected without requiring subsequent costly operations for removal of the installation in the molding die while yet suitable electrical interconnecting means. The connecting member is severed substantially concurrently with the molding operation and by means of apparatus associated directly with the molding dies, whereby substantially increased economy and facility of manufacture is obtained.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of forming an electrical male plug, comprising the steps of: providing a pair of spaced electrical terminals having a connecting portion therebetween effectively maintaining the terminals in accurately spaced relationship; fixedly mounting the connected terminals in a mold means; and substantially concurrently severing the connecting portion while so fixedly mounted by projecting shearing members into the mold means to provide elec trical clearance between said terminals followed by withdrawing the shearing members to complete the mold cavity and molding a body of substantially solid insulating material by injecting insulating material about the severed connecting portion and a portion of said terminals and solidifying the insulating material to form a plug body thereabout while maintaining said accurately spaced relationship of said terminals.

2. The method of claim 1 wherein said severing step comprises a step of severing said connecting portion from only one of said terminals.

3. The method of claim 1 wherein said severing step comprises a step of severing said connecting portion from both terminals.

4. The method of claim 1 wherein said connecting portion is retained within the plug body.

5. The method of claim 1 wherein said connecting portion is folded during the severing operation.

6. The method of claim 1 wherein said connecting portion is disposed by the severing means to reinforce the plug body between said terminals.

7. The method of claim 1 including the steps of inserting a support into the mold means to support the connecting portion during the severing operation, and withdrawing the support during completion of the molding operation.

8. The method of claim 1 including the steps of inserting a support into the mold means to support the connecting portion during the severing operation, and withdrawing the support during completion of the molding operation, said support being disposed in the withdrawn condition to define a portion of the mold means.

9. The method of claim 1 wherein said severing step comprises a step of severing said connecting portion by inserting a shearing means into the mold means and withdrawing the shearing means to define a portion of the mold means.

It). The method of forming an electrical male plug, comprising the steps of:

providing a pair of spaced electrical terminals having a connecting portion therebetween effectively maintaining the terminals in accurately spaced relationship;

placing the connected terminals in a mold means; and

inserting into the mold means means for supporting the connecting portio and means for shearing the supported connecting portion to sever the connecting portion for providing electrical clearance between said terminals and substantially concurrently molding a body of insulating material about a portion of said terminals and said severed connecting portion to form a plug body thereabout.

(References on following page) 5 6 References Cited 3,212,171 10/1965 Echter 29597 UNITED STATES PATENTS 2 533 31 7/1966 Gehl- 2/1937 Wanace ,0 7/1967 Cloyd et a1 18--36 11/1915 Cook 29155.55

12/1956 Malcolm 264 1O3 X 5 JOHN F. CAMPBELL, Przmary Exammel 5/1944 Seele 264-261 ROBERT W. CHURCH, Assistant Examiner.

7/1966 Richard 29155.55

1/1940 Haller 29630 US. Cl. X.R.

x132: SS Q III: 258 10 18-36; 29206, 416, 598, 630; 264272; 33962, 102

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