US2239331A

US2239331A - Method of producing connector parts

Info

Publication number: US2239331A
Application number: US318090A
Authority: US
Inventors: Frederick W Mebold
Original assignee: James R Kearney Corp
Current assignee: James R Kearney Corp
Priority date: 1940-02-09
Filing date: 1940-02-09
Publication date: 1941-04-22
Anticipated expiration: 1958-04-22

Description

April 22, 1941. F. w. MEBOLD 2,239,331 METHOD or rnonuczue CONNECTOR PARTS Filed Feb. 9, 1940 :s Sheets-Sheet 1 '9' 9 i 26 I Mus/970E 6 fkfoze/c/r Mme-5040 1.7 Y .Arra'e/YEY F. w. MEBOLD 2,239,331 METHOD OFPRODUCING CONNECTOR PARTS Filed Feb. 9, 1940 3 Sheets-Sheet 2 ATro/e/YEY.

April 22, 1941.

F. w. MEBOLD 2,239,331

METHOD 6F PRODUCING CONNECTOR PARTS Filed Feb.9, 1940 3 Sheets-Sheet 3 x {T ,c" 41 A rrak/vgv Patented Apr. 22, 1941 METHOD OF PRODUCING CONNECTOR PARTS Frederick W. Mebold, St. Louis, Mo., assignor to James R. Kearney Corporation, St. Louis, Mo.,

a corporation of Missouri Application February 9, 1940, Serial No. 318,090

9 Claims. (Cl.

This invention relates to the manufacture of clamping members and more specifically to an improved method and means for producing connectors of the side opening type now employed to a considerable extent in the power transmission branch of the electrical industry for engaging electrical conductors, and for connecting electrical conductors together, the predominant object of the invention being to provide an improved method of producing parts of such side opening connectors through the use of which the cost of producing the connector parts is very greatly reduced. This object of the invention is accomplished by the provision of a'unique manufacturing method in accordance with which relatively few machine operations are required to produce the finished connector parts and in the use of which there is practically no waste of the material from which the connector parts are formed.

Connectors of the type to which this invention relates must necessarily be made up of parts which are accurately made and which are provided with smooth, machine finishes, which heretofore could ordinarily be accomplished only by expensive casting and machining processes. In accordance with the present invention, however, the connector parts are produced from relatively soft, ductile metal, such as copper, or alloys having the required characteristics, each connector part beingformed from a blank of material with the aid of punch and die means, and the operation of forming the part combining drawing, stoving, swaging, and extruding operations which results in the production of a connector part densified and hardened to the maximum without the use of heat treating or tempering operations. In the production of connector parts in accordance with the present invention the body of metal from which a connector part is being produced is worked in such manner that the grain structure of the metal is not disturbed, and as a result of this situation a perfect connector part, free from flaws or defects, is produced. Also because of the improved method of producing connector parts in accordance with this invention no machining of the parts is required after the parts have been produced.

Fig. 1 is a plan view of a strip of material and showing the manner in which blanks are struck therefrom which are employed in producing connector parts in accordance with this invention.

Fig. 2 is a plan view illustrating a die having one of the blanks associated therewith prior to the commencement of the operation of forming a connector part from said blank.

Fig. 3 is a vertical section taken on line 3--3 of Fig. 2 with a punch included.

Fig. 4. is a vertical section resembling Fig. 3 but showing the improved method of producing a connector part when it has progressed beyond the initial stage illustrated in Fig. 3.

Fig, 5 is a vertical section resembling Fig. 4 but showing a later stage in the production of a connector part in accordance with the invention.

Fig. 6 is a vertical section taken on line 6-6 of Fig. 5.

Fig. 7 is a fragmentary horizontal section taken on line l'-l of Fig. 6.

Fig. 8 is a fragmentary section illustrating the manner of providing a connector part being prodnced in accordance with the invention with an opening which constitutes a part thereof.

Fig. 9 is a plan view of a strip of material showing the manner of striking blanks therefrom which are employed in producing another part of a side opening connector.

Fig. 10 is a plan view' illustrating a die employed in producing a connector part from one of the blanks illustrated in Fig. 9.

Fig. 11 is a vertical section taken on line l i--! I of Fig. 10 with a punch included.

Fig. 12 is a view similar to Fig. 11 but showing the improved method of producing a connector part when it has progressed beyond the initial stage illustrated in Fig. 11.

Fig. 13 is a view similar to Fig. 12 but illustrating a later stage of the production of a connector part in accordance with the invention.

Fig. 14. is a vertical section taken on line i l-44 of Fig. 13.

Fig. 15 is a fragmentary horizontal section on line i5l5'of Fig. 13.

Figs. 16 and 1''! illustrate still later stages of the production of a connector part, the earlier stages of which are illustrated in Figs. 10, 11, 12, 13, 14, and 15.

Fig. 18 is a fragmentary section illustrating 1e manner of providing the connector part whose method of manufacture is illustrated in Figs. 9 to 17, inclusive, with an opening which constitutes a part thereof.

Fig. l9-illustrates a modified manner of producing the connector part to whose manufacture Figs. 9 to 17 relate.

Fig. 20 is a perspective of the connector part whose method of production is illustrated in Figs. 1 to 8, inclusive.

ig. 21 is a perspective of the connector part whose method of production is illustrated in Figs. 9 to 18, inclusive.

Fig. 22 is a perspective of an assembled side opening connector of the type to which this invention relates.

In the drawings, wherein are illustrated for the purpose of illustration, merely, various methods of producing connector parts in accordance with the invention, Figs. 1 to 8, inclusive illustrate the improved method of producing the connector part Ca shown in Fig. 20. In producing the connector part Ca blanks l are first struck from a strip of material I as shown Fig. 1, said blanks being of such dimensions with respect to the strip of material I and of such shape that no material is wasted in their production.

In producing the connector part Ca a die 2 is employed which is provided with a cavity 3 formed therein, said cavity being of such shape that the connector part Ca may be produced therein. At its lower end the die 2 is provided with a plate :3 through which is formed an opening l that is alined with the cavity 3 of the die. Qperating through the opening l of the plate i is a shutter, or knock-cut plunger 5, said shutter being provided with an enlarged head portion 5 that is located within the cavity 3 of the die 2 and having a shoulder 5a which contacts with the top face of the plate t to limit downward movement of the shutter with respect to the die. As shown in Figs. 3, 4, 5, and 6 the enlarged head portion 5 of the shutter provides the bottom of the cavity 3 of the die and the top face of said head portion is substantially flat. At the upper end of the die 2 the walls of the cavity 3 thereof are flared as shown in Figs. 2 to 6, inclusive, to provide substantially curved surfaces El which constitute very imp rtant features of the invention. Also at its top the die 2 is provided with opposed gage plates "i which are notched as indicated at '5' in Fig. 2 to receive opposed end portions of a blank l which is associated with the die preparatory to he commencement of the operation of producing a connector part from said blank.

When one of the connector parts Cd is to be produced in accordance with this invention, one of the bi nks l is supported by the top face of the die 2 at the flared upper end of the cavity 3 f said die, opposite portions of said blank being received by the notches l of the gage plates 2 so as to maintain the blank in. proper position with respect to the top, open end of the cavity of the die as shown in Figs. 2 and 3. With the blank arranged with respect to the die 2 as described, and as shown in Figs. 2 and 3, a punch 3 is moved against the blank I and into the cavity of the die, such movement of the punch into the cavity of the die carrying the metal of the blank into said cavity of the die. The punch 8 is elongated and is shaped in cross-section as shown in '7; that is to say said punch includes a portion 8a which is provided with a pointed lower end (see Fig. 6), and a narrower portion 81) whose opposite side faces are spaced from the corresponding side walls of the die cavity as shown in Fig. 7.

As the punch 8 moves against the blank l the pointed lower end of the punch portion 8a contacts with the portion in of the blank, while the lower portion of the punch portion Eb contacts with the intermediate blank portion lb which is located between the oppositely extended portions to of the blank. During initial movement of the punch into the cavity of the die the metal of the blank is worked by coacting faces of the die and punch to cause the portions 10 of the blank to assume the positions in which they are shown in Fig. l, and as the punch continues its downward movement within the cavity of the die the metal of the portions lc of the blank is forced to fill the spaces between the opposed side faces of the punch portion 8?) and the corresponding side walls of the die cavity to provide the parallel elements 9 of the connector part Ca. Also the lower end face of the punch portion to in cooperation with the top face of the head portion of the shuttle 5 and the die cavity walls, forms the portion it of the connector part which bridges the lower ends of the parallel elements 9 of said connector part, while the lower, pointed end of the punch portion 8a cooperates with the top face of the head portion of the shuttle and with the die cavity walls to produce the portion ii of the connector part Ca.

An extremely important feature of the invention resides in the fact that the operation of forming the connector part Ca combines drawing, extruding, and swaging, operations, and an operation which is known in the metal working art as 'stoving, this term describing an action where metal is crowded into itself, or is subjected to a squeezing action or to compression. An important characteristic of the stoving action is that it maintains the grain structure of the metal in an undisturbed condition while the metal is being worked, as distinguished from drawing and other metal working operations which tend to down the grain structure of the metal during working thereof. The stoving action referred to above is employed in producing the parallel elements 9 of the connector part Ca, and said action is produced by the manner in which the surfaces F; of the die 2 and surfaces of the punch 8, which cooperate with said surfaces 5, act upon the portions of metal of which said parallel elements are being produced. In other words, when the parallel portions 9 are being formed the metal portions are subjected to a drawing action, but, at the same time said metal portions are subjected to a stoving action which crowds the metal portions being worked into themselves and thereby maintains the grain structure of said metal portions in an undisturbed condition, with the result that flaw-free parallel portions 9 of the maximum density and hardness are produced.

The extruding action, which forms a part of the operation of producing a connector part in accordance with this invention, results from the action of the punch 8 forcing the metal of which the connector part is being formed in all directions to fill the effective part-forming portion of the cavity 3 of the die, and the swaging action is produced by the formation of the V-shaped seat i l in the top surface of the portion 1 l of the connector part Co by the pointed lower end of the punch portion So.

It is to be noted that opposed walls of the cavity 3 of the die 2 are provided with pointed projections l2, as shown to the best advantage in Figs. 2 and 7. These projections serve to provide the parallel elements 9 of connector part Ca with depressions 9' which extend longitudinally thereof, as shown in Fig. 20, and which are substantially V-shaped in cross-section.

When the connector part Co has been preliminarily formed in the die 2, as described above, said part is ejected from said die by upward movement of the shutter 5. The connector part is then introduced into a die l3, shown in Fig. 8, for the operation of punching a hole i l (see Fig. 20) through the portion Ill of said connector part. The die l3 has a cavity i3 formed therein which receives a shutter l5, said shutter having an opening i5 formed longitudinally therethrough. Also the shutter is provided with opposed cavities I6 shaped and dimensioned to receive the parallel elements 9 of the connector part Ca. When the connector part Co is applied to the die it the parallel elements 9 thereof are introduced into the cavities l6 and the portion ill of the connector part contacts with the top face of the shutter l5 as shown in Fig. 8. The die l3 includes a movable portion I! through which an opening it is formed, and operating through this opening is a punch 18. The movable die portion i1 and the punch 18 are operated by suitable means (not shown) for moving said movable die portion and said punch relative to the stationary portion of the die and With respect to the shu ter l5.

When the preliminary formed connector part Ca is to be provided with the hole It, the movable die portion H and the punch [3 are withdrawn to a position in spaced relation with respect to the stationary die portion and. the conhector part is introduced in place shown in Fig. 8. The operating mechanism associated with the die portion l1 and with the punch is then operated to move the movable die portion against the connector part Ca and to force the punch l8 through the portion H! of said connector part to provide the hole M. While the hole It is being formed as described certain sharp corners of the connector part Ca are being rounded off by the shutter 15 and the movable die portion l'l, these corner rounding operations being performed in an obvious manner at the points indicated by the reference character It in Fig. 8.

The side opening connector, to the manufacture of which this invention relates, includes also a connector part Cb which is illustrated in perspective in Fig. 21, said connector part Cb being produced preliminarily with the aid of a die2ll illustrated in Figs. 10 to 14, inclusive. The die 20 is provided with a cavity 20 formed therein which is of the proper shape to form the connector part Cb and which is open at the top and bottom of the die, the walls of said cavity being flared at the top of the die to provide substantially curved faces 2!. Mounted on the top surface of the die 20 is a pair of opposed gage plates 22 which are notched, as indicated at 22', to provide recesses adapted to receive opposed portions of a blank from which a connector part Cb is to be formed.

Associated with the die 2b is a pair of clippers 23 which are shaped as shown to the best advantage in Figs. 12, 13, and 14. In other words, each of said clippers comprises a bar which is rectangular in cross-section and said bars are supported in vertically extended recesses 23' formed in the die 25. The upper portion of each clipper and the lower portion thereof are wider than an intermediate portion located between said wider portions, as shown in Fig. 14, there being an opening 2:1 provided between the lower edge Eta of the upper, wider portion of each clipper and the top edge 24b of the lower, wider portion of said clipper. The top edges 24b of the lower wider portions of the clippers 23 (Fig. 14)

are cutting edges which serve a function to be hereinafter set forth.

Assembled with the die 29 is [a punch 25 whose bottom portion is shaped so as to form the conhector part Cb in the operation of the apparatus comprised of the die 20 and said punch 25. The punch 25 includes a portion 25a with opposite side faces of which the inner edges of the wider upper and lower portions of the clippers contact. The punch also includes a portion 25b which is provided with a pointed lower end 250, and the lower edge of the portion 25aof said punch is disposed at a slight angle to the horizontal as shown at 25d in Fig. 12.

In producing a connector part Cb with the aid of the die, and. punch assembly illustrated in Figs. 11 to 14, inclusive, a blank 26 is assembled with the die 2%] as shown in Figs. 10 and 11; that is to say the blank rests on the top surface of the die with opposite end portions thereof disposed in the recesses 22' of the gage plates 22 and with the lower edges 25a of the upper, wider portions of the clippers overhanging the top face of the blanks. With the blank so positioned the punch 25 starts its downward movement against said blank and the metal of the blank is carried into the upper portion of the cavity 29 of the die as shown in Fig. 12. During movement of the material of the blank into the upper portion of the cavity of the die, the curved faces 21 of the die, together with faces of the punch which cooperate with said curved faces of the die, subject the portions of the metal of the die which forms the portions 21 of the connector part 0b (to combined drawing and stoving actions. As a result of this situation the metal is crowded into itself while the portions 21 are being formed and as a con-sequence the grain structure of the metal is undisturbed while said portions 21 of the connector part Cb are being formed. The downward movement of the punch through the cavity of the die is continued, and as the body of metal from which the connector part is being produced moves past the cutting edges 24b of the clippers 23, portions E ie are sheared from said body of metal to provide the connector part with the recesses 24d which are located at opposite sides of the finished connector part Cb. After the shearing operation has been completed movement of the punch is continued until the preliminarily shaped connector part is discharged from the die cavity at the lower end thereof, the slugs of material f ic dropping from the die when (the punch is moved upwardly after discharge of the connector plant from the die, or being ejected by a succeeding blank;

When the preliminarily formed connector part is discharged from the cavity of the die 20 it ap pears as shown in Fig. 16, wherein said connector part is designated by the reference character Cb. The preliminarily formed connector part is then subjected to an additional operation with the aid of the punch and die assembly shown in Figs. 16 and 17. The punch and die assembly shown in Figs. 16 and 1'7 comprises a die 28 having a cavity '28 formed therein in which is disposed for operation a shutter 29, said shutter being shaped at its top to conform generally to the shape of a portion of the preliminarily formed connector part Cb. Also the punch and die assembly illustrated in Figs. 16 and 17 includes a punch to whose lower portion is shaped to complete the shaping of the connector part; in other words the bottom face of the punch 3!] is fiat to produce the flat face 3| of the connector part Cb except for a pair of cavities 32 which form the lugs 33 on said connector part Cb.

When formation of the connector part Cb is to be completed with the aid of the punch and die assembly illustrated in Figs. 16 and 17, the preliminarily formed connector part is arranged on the shutter 29 as shown in Fig. 16. The pantforming end portions of the shutter 29 and the punch so, with the partially formed connector part disposed therebetween, are then moved into the cavity of the die 23 where pressure is applied to the partially formed connector part by the shutter and punch to give to the connector part its final form. t is to be noted that the angular face of the connector part Cb which is formed by the lower end 25d of the punch portion 25a, shown in Figs. 12 and 13, is made horizontal in the final operation of forming the connector part Cb by the face 29 of the shutter 29 shown in 16 and 17, to provide the face 34 of the connector part Cb. This angular face is formed in the early stages of producing the connector part Cb only to assure, during the final state of producing the connector part, the presence in the proper position of sufficient metal to form the lugs 33 of said connector part Cb. Also, the pointed portion Eta of the shutter 29, shown in Figs. 16 and 17, obviously produces final shaping of the V-shaped seat 35 of the connector part Cb.

After the connector part Cb is removed from the punch and die assembly shown in Figs. 16 and 17 it is transferred to a perforating die assembly, such as that il ustrated in Fig. 18, where the connector part is gripped between

members

35 and 31 and certain corners thereof are rounded ofi as indicated at 35 and 37. A punch 38 is then operated, by mechanism not shown, to form a hole 39 through a portion of the connector part, the wall of this hole, after removal of the connector part from the perforating die assembly, being provided with screwthreads as shown in Fig. 21.

The connector parts Ca and (3b are assembled as shown in Fig. 22 to produce the complete connect'or C, said complete connector including a headed bolt 4b which extends through the opening M of the connector part Ca and through the opening 29 of the connector part CD in screwthreaded engagement with the screwthreaded wall thereof. Obviously rotation of the bolt 46 will adjust the connector part Cb relative to the connector part Ca, the parallel elements 9 of said connector part Cd guiding the connector part Cb during such movement. part Cb may be adjusted with respect to the connector part Ca so as to cause conductors, or other elongated elements to be clamped between the V-shaped seats l i and 35 of the connector parts Ca and Cl) respectively.

In Fig. 3.9 a modified method of producing the connector .part Cb is illustrated which differs rom the method shown in Figs, 10 to 1'7, inclusive, in that the method illustrated in 19 involves producing the connector part Cb in one continuous operation instead of in two separate operations as shown in Figs. 10 to 1'7, inclusive. In Fig.1?) adie ll is employed which is provided with a die cavity 44' in which a shutter 42 is disposed and in which a punch 13 operates. In view of the explanation heretofore made regarding the formation of the connector part Cb, it is thought that the method of procedure in accordance with the method illustrated in Fig. 19 would be obvious to one killed in the art to which the Thus the connector 1;

invention relates, the punch and shutter of the assembly of Fig. 19 cooperating to produce the connector part during a single operation of the assembly.

The substantially curved surfaces 6 and 2|, previously referred to herein, are preferably formed by a series of short, straight, angularly disposed face portions, which combine to produce what appears as curved surfaces. By so producing said curved surfaces minute angles are formed on the substantially curved surfaces which aid in the sto'ving operations.

I claim:

1. The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, and an extruding operation which forms said bridge portion.

2. The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, and extruding and swaging operations which form, said bridge portion.

3. lhe herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portion, and extruding and swaging operations which form said bridge portion, and a punching operation for providing said connector part with a hole.

4. The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, and extruding and swaging operations which form said bridge portion, and a separate punching operation for providing said connector part with a hole.

5. The herein described method of producing a part intended for use in a connector structure, comprising forming said part with the aid of a punch and die assembly, the operation of forming said part including simultaneously performed drawing, stoving, shearing, and extruding operations.

6. The herein described method of producing a part intended for use in a connector structure,

comprising forming said part with the aid of a punch and die assembly, the operation of forming'said part including simultaneously performed drawing, stoving, shearing, and extruding operations, and a swaging operation.

'7. "The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, a shearing operation which removes from the body of metal being acted on portions thereof, and an extruding operation which forms said bridge portion.

8. The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, a shearing operation which removes from the body of metal portions thereof, and extruding and swaging operations which form said bridge portion.

9. The herein described method of producing a connector part which includes spaced parallel portions and a bridge portion that connects said parallel portions, said method comprising forming said connector part with the aid of a punch and die assembly, said operation of forming said connector part including simultaneously performed drawing and stoving operations which form said parallel portions, a shearing operation which removes from the body of metal portions thereof, and extruding and swaging operations which form said bridge portion, and a separate punching operation for providing said connector part with a hole. I

FREDERICK W. MEBOLD.