US3429041A

US3429041A - Method of making an electrical connector

Info

Publication number: US3429041A
Application number: US386649A
Authority: US
Inventors: Roy A Patton Jr
Original assignee: ROY A PATTON JR
Current assignee: ROY A PATTON JR
Priority date: 1964-07-31
Filing date: 1964-07-31
Publication date: 1969-02-25
Anticipated expiration: 1986-02-25

Description

Feb. 25, 1969 R, A, PATTON JR 3,429,041

METHOD OF MAKING AN ELECTRICAL CONNECTOR Filed July 5l, 1954 INVENTOR ROY A. PATTON, Jr.

MM, mi w ATTORNEYS Feb 25, 1969 R. A. PATToN, JR 3,429,041

METHOD OF MAKING AN ELECTRICAL CONNECTOR Filed July 3l, 1964 Sheei'I 2 ROY A. PATTON, Jr.

AFTORNEYS Feb. 25, 1969 R, A, PATTON, JR 3,429,041

METHOD OF MAKING AN ELEOTR'OAL CONNECTOR Filed July 31, 1964 sheet 3 of s INVENTOR ROY A. PATTON, Jr.

SYM

ATTORNEYS United States Patent O 3,429,041 METHD F IVIAKING AN ELECTRICAL CNNECTOR Roy A. Patton, Ir., 6030 N. Shore Drive, Grabill, Ind. 46741 Filed July 31, 1964, Ser. No. 386,649 U.S. Cl. 29-629 15 Claims Int. Cl. HZg 15/08; H01r 43/06; B29f l/IO ABSTRACT 0F THE DISCLQSURE A method of fabricating electrical connector parts comprising the steps of extruding a rod of insulating material having passages therein, cutting the rod to certain lengths, and turning at least one of the ends of said rod to form steps in relation to said passages.

The present invention relates to an electrical connector, and more particularly to a multiple circuit connector composed of plug and socket parts which may be detachably connected together.

The development of miniaturized and microminiaturized electronic equipment has, as a matter of necessity, forced the development of miniaturized components such as capacitors, transistors, inductors, connectors and the like. As a result of this miniaturizing, re-design of these components has been required, and in some instances such re-designed, miniaturized components have suffered a considerable loss in reliability. While such components quite frequently constitute only a small part of a much larger piece of equipment or system, the failure of the part many times can produce failure of the system. Further, problems have been encountered in miniaturizing connectors so as to fit them into the space limitations permitted by miniaturized electronic or electrical equipment. It has been found that such miniaturized connectors are especially a constant source of trouble and equipment failure.

It is therefore an object of this invention to provide an electrical connector and a method for fabricating the same which is extremely small in size yet reliable, durable and efficient in use and relatively inexpensive to manufacture.

It is another object of this invention to provide an electrical connector wherein a maximum number of circuits can be completed in a minimum amount of space.

It is yet another object of this invention to provide a multiple circuit connector having miniature and microminiature contact elements which are replaceable whenever they become defective.

Other objects will become apparent as the description proceeds.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. l is a fragmentary side view showing the male and female coupling elements of the electrical connector of this invention in disconnection;

FIGS. 2a and 2b are side views of the male and female coupling elements of the electrical connector of FIG. 1 prior to the connection of wires to the terminal ends;

FIG. 3 is a contact end view of the female coupling portion of the electrical connector of this invention taken substantially along the section line 3 3 of FIG. 2b;

FIG. 4 is a perspective View of the male connector element of this invention shown in side elevation in FIG. 2a;

FIG. 5 is an axial, sectional View of the coupling elements of FIGS. 2a and 2b shown in mating relationship;

ice

FIG. 6 is an enlarged fragmentary, sectional View of the male coupling element of the electrical connector of this invention illustrating the detent configuration of the distal end of the connectors and the structure allowing the connectors to flex in a radial direction;

FIG. 7 is a perspective view of the male. coupling element of a second embodiment of the electrical coupling of this invention;

FIG. 8 is a side view, in cross-section, of the female coupling element of the second embodiment of the electrical connector of this invention;

FIG. 9 is a perspective view of an extruded rod segment which is fabricated during the performance of both of the methods of this invention;

FIG. 10 is a perspective view of the connectors used in the manufacture of the second embodiment of the male coupling element of this invention shown in FIG. 7;

FIG. 11 is a perspective view of the electrical connectors used in the manufacture of the second embodiment of the female coupling element of this invention shown in FIG. 8;

FIG. 12 isa fragmentary side view, partly in cross-section, of an apparatus for performing a method for fabricating the first embodiment of the electrical connector of this invention;

FIG. 13 is a sectional view of the apparatus of FIG. l2 taken substantially along the section line 13-13;

FIG. 14 is a fragmentary side view, partly in cross-sec` tion of an apparatus for performing a method of fabricating the second embodiment of the electrical connector of this invention; and

FIG. 15 is a cross-sectional view of the apparatus shown in FIG. 14 taken substantially along section line 15-15.

In the broader aspects of this invention, an electrical connector is provided comprising a substantially rigid body of insulated material having a plurality of axially extending elongated conductor elements secured in the body by a lock means. The conductor elements are exposed at both ends of the body, and at one end are capable of flexing radially inwardly ofsaid body.

Referring to the drawings, and more particularly to FIGS. l through 6, an electrical connector indicated generally by the numeral 20 is composed of two parts, a male coupling element 22 and a female coupling element 24. These two parts are constructed almost identically such that a description of one will substantially suffice for the description of the other.

In the main, the connector is composed essentially of a cylindrically shaped body 23 of insulating material. This material is preferably plastic and may be a thermoplastic, thermosetting or of a solvent soluble type. Specifically, Mylar, Teflon, polyethylene, vinyl, Bakelite, phenolics and the like are satisfactory. Whatever material may be used, the body 23 should be relatively rigid and should not deform under localized pressure or deform as does soft rubber. When compared to the metallic contact elements which will be described later, the body material may be regarded as rigid and non-flexible. Body 23 of male and

female coupling elements

22, 24 has

opposite ends

28, 30,

mating portions

32, 34 adjacent ends 28, respectively, and terminal portions 36 adjacent end 30.

Elements

22, 24 have a plurality of axially extending passageways 26 which communicate with

ends

23, 30. Passageways 26 are arranged in a plurality of coaxial and circular sets which are circumferentially and equally spaced-apart from each other. Each passageway 26 is identical in cross-sectional size and shape and in length. In the specific embodiment illustrated, passageways 26 are shown to be rectangular in cross-section; however, it is within the scope of this invention for passageways 26 to be square, round or other shapes. Terminal portion 36 has a number of integral, coaxial and different diametered step portions equal in number to the coaxial sets in which the passageways 26 are arranged. In the specific construction illustrated two coaxial sets are shown and two

step portions

38, 40 comprise portion 36; however, it is within the scope of this invention to have any number of sets and potrions. Axially extending passageways 26 communicate with the surfaces of

portions

38, 40 forming a plurality of axially extending grooves which communicate with the

distal ends

30, 39 of

portions

38, 40, respectively. Portion 40 has a diameter which is smaller than portion 38 and extends axially outwardly beyond portion 38 so as to have a portion of grooves 42 in each of the portions 38, 4d which are exposed.

Referring now to portion 32 adjacent end 28 of male coupling element 22, there are illustrated two

step portions

44, 46 which like

step portions

38, 4@ are coaxial, integral, and lof cylindrical shape. Portion 44, which has the smallest diameter, axially extends beyond the portion 46.

Portions

44, 46 also have the longitudinal grooves 42 extending their axial length and communicating with the distal ends 28, 48 of the

portions

44, 46, respectively.

In each of the passageways 26 of the male coupling element 22 is securely fitted a straight, elongated conductor indicated generally by the numeral 50. This conductor S has a cross-section of substantially the same size and shape as the passageway 26. Conductors 50 have substantially the same length as the combined length of the grooves 42 and passageways 26 extending from distal end 428 to the distal end 38 of

portions

40, 44 respectively, and from the,

distal end 48 of portion 46 to the distal end of portion 38, respectively. Conductors 50 are of some suitable conductive metal, examples being bronze, brass, copper, aluminum, gold, silver, platinum or alloys thereof. A particularly useful material is beryllium copper. As will appear from the following description, it is desirable for these elements S0 to be resilient and in this respect to correspond to bar springs.

The construction thus far described is of stepped diametered configuration at the opposite ends as clearly shown in FIG. 2a. As above-described, end portion 32 may be regarded as the coupling or plug end, while the opposite end may be considered as the terminal end. At both ends, each of the conductors has an exterior surface which is exposed, equal in length to the exposed portion of the grooves 42 above mentioned. At the terminal end, this permits easy attachment, such as by soldering, welding or crimping of wires to the terminal ends of each of the conductors 50. This is particularly important in the case in which the connector is extremely small in diameter. As the terminal ends of the conductors are circumferentially and equally spaced apart as are the passageways 26, wires may be attached to the conductors 50 with a minimal chance of short circuit. The attachment of the wires to the terminal ends of the conductors is illustrated in FIG. l.

At the plug end (FIG. 4), the opposite ends of the conductors 50 are embedded in the grooves 42 of the

step portions

44, 46 and have their outer surfaces exposed the entire length of the aforesaid step portions. In some cases, it is desirable that the conductors 50 be raised slightly above the surface of the

step portions

44, 46 for the reasons which will become apparent from the following description.

Adjacent the distal ends 28, 48, the

portions

44, 46 and the conductors S0 are formed with detent shapes. In axial section, (see FIG. 6) the surface of the

step portions

44, 46 is smoothly undulating with a crest 52 being adjacent to the

ends

28, 48 and a valley 54 being rearwardly thereof. The conductors 50 have a shape which is identical in all respects to the shape of the surface of the

step portions

44, 46. Immediately beneath the distal end `56 of the conductor Sil, the respective portions of the

step portions

44, 46 are undercut or formed to provide for a tapered space or gap 58. Thus, the distal end `56 of each conductor may be dellected radially inwardly until the bottom of the gap 58 is engaged. It is therefore desirable for the conductor 5t) to be resilient such that when the deflecting force is removed therefrom, it will spring back to the position shown in FIG. 6.

The female coupling element 24, shown in FIGS. 2b and 3 is constructed essentially the same as the male coupling portion 22, above described, with the exception that the

step portions

44, 46 are formed within the body of the element 24 thereby providing a socket configuration in the portion 34 adjacent end 28 rather than the plug conguration in the portion 32 aforedescribed. The

step portions

44, 46 and the conductors 58 are of substantially the same diameters and cross-sectional shapes and dimensions abovedescribed in reference to the male coupling element 22, and conductors 50 are the same in number and are also spaced circumferentially apart. The socket portion 34, shown in FIG. 2b, however, is of complementary size and shape to the plug portion 32 so as to mate therewith with the

step portions

44, 46 of the socket portion 34 in an overlapping manner. (See FIG. 5.) The distal ends S8 of the conductors 50 in the socket portion 34 are shaped to complement the

detent configuration

52, 54 of the plug portion 3-2 described above. Similarly, the

step portions

44, 46 of the socket portion 34, while substantially cylindrical, are shaped to complement the coniiguration of the same numbered step portions of the plug portion 32 so as to intimately lit together as shown in FIG. 5.

When the male coupling element 22 and the female coupling element 44 are tted together, the inner peripheral surfaces of the socket portion 34 and the contacting surfaces of the elements 50 mate intimately and axially overlie and engage the outer peripheral surfaces of the same numbered step portions and conductors of the plug portion 32. Desirably, the diameters of the socket portion 34 are slightly smaller than the companion diameters of the plub portion 32 such that when the male coupling element 22 and the female coupling element 24 are engaged, the distal ends 58 of the conductors 5t) will be sprung radially inwardly slightly so as to provide the intimate conductive contact necessary between elements 50 of the respective coupling elements 2.2, 24.

While the conductors 56 of the plug portion 32 can spring inwardly because of the relief 58 formed in the

step portions

44, 46 adjacent end 28 of the male coupling r element 22, still it is within the scope of this invention to relieve or taper the underside of the contacts 5t) beneath the distal end 56. Also the socket portion 34 may be formed with reliefs similar to the relief 58 (FIG. 6) for permitting such springing action.

In a miniature or a microminiature version of the connector thus far described, the conductors 50 are extremely small and may correspond in size to No. 34 copper wire. Obviously, if two ends of a wire of this size were butted together, the contact resistance would be extremely high as the area of contact would be relatively small. As is clearly shown in FIG. 5, the male and

female coupling elements

22, 24 do not abut in end-to-end relationship but instead the conductors 50 of the aforementioned elements overlap for a substantial distance so as to provide a relatively large contact area. By virtue of the exing of the conductors 50 of the relatively long axial and overlapping lengths of the same, a contact resistance of a negligibly low value is obtained. As is well known in the art, such low contact resistance in a miniaturized connector is an essential requirement in almost every case.

The detent shapes of the

step portions

44, 46 are such as to permit the plug portion 32 and the socket portion 34 to be connected and disconnected manually. The detent curvatures may be gradual and elongated as already shown and described or in the alternative may be sharply pronounced and relatively short. Obviously, modifying the detent shapes of the plug portion 32 and the socket portion 34 will determine the ease with which the

coupling elements

22, 24 may be connected and disconnected. Also, the degree of rigidity that the two

coupling elements

22, 24 have when connected will be determined by the same detent configuration. The principal purpose of the detent is to lock the two parts together, to resist separation thereof, and to create wiping action between conductors thereby to minimize pitting corrosion or deterioration thereof. While no means other than the detent has been shown for accomplishing such locking purposes, still the conventional screw-type coupling may be added to the other portions on the

coupling elements

22, 24 intermediate the

ends

28, 30 for this purpose if a tighter connection is desired.

Referring now to FIGS. 7 and 8 there is shown a second embodiment of the male and

female coupling elements

22, 24. Both parts of this second embodiment of the electrical connector of this invention are identical in all respects as above described except for the method by which the conductors 50 are mounted and secured within the

coupling elements

22, 24. Referring to FIGS. 10 and 11, there is shown in perspective View, the conductors 50a and 50h which are used in the second ernbodiment of this invention. Conductor 50a is substantially of the same size, cross-sectional configuration and length as the conductor 50 used in the first embodiment and has the crest 52 and the valley 54 adjacent the distal end 5.6 in the upper surface thereof, as aforedescribed. The only difference between the conductor 50a and the conductor 50 which was aforedescribed in reference to the male coupling element 22 is the detent 60 which is formed in the bottom surface of the conductor 50a adjacent but spaced apart from the end 62 opposite the distal end 58. Conductors 50cl are removably secured in the passageways 26 by means of this detent 60 and an annular groove 64 which is machined in both of the

step portions

38, 40 of both the

coupling elements

22, 24 spaced from the distal ends 30, 39 respectively. More specifically, conductors 50a are slid through the previously formed passageways 26 until the conductors 50a positioned in the passageways 26 so that the detent 60 will engage the groove 64. The resiliency of the conductor 50a holds the detent 60 in passageway 64 thereby securing the same within the passageway 26 until the end 62 of the conductor 50a is lifted thereby removing the detent 60 from the groove 64. Similarly in all respects, the conductors 50h are positioned in the second embodiment of the female coupling element 24 illustrated in FIG. 8. Each conductor 50b has the crest 52 and the valley 54 adjacent the distal end 58 in the bottom surface thereof as distinguished from the conductor 50a. Conductors 58h are, however, identical to the conductors 5t) which are mounted in the female coupling element 24 in all respects except for detent 66 and their method of attachment.

The removable securance of the conductors 58a and 50b in the second embodiment of the electrical coupling of this invention provides for easy maintenance of the connector which is not possible with the first embodiment. As the

conductors

50, 50a, 50b are the portions of the electrical connector receiving the wear and therefore likely to deteriorate with use or mishandling, by providing that the conductors are replaceable, the life of the electrical connector may be prolonged indefinitely. Further, since the conductors may lose resiliency and therefore not contact each other when in mating position over the entire exposed surface of the conductor, contact resistance may with age increase to a value that cannot be tolerated and therefore make the conductor useless as aforementioned. By the replacement of the

appropriate conductors

50, 50a, 50h these maladies can be corrected easily.

Referring now to FIGS. 9, 12 and 13, an apparatus and method for manufacturing the first embodiment of the electrical connectors of this invention will not be described. In FIGS. 12 and 13 there is shown diagrammatically an apparatus generally comprising a bin 70 containing a resin charge 72, a feeding mechanism 74, which can either be of the piston type, the screw type or any similarly performing mechanism, and an elongated mold 76 having a plurality of core rods 78 extending therethrough and a cooling jacket surrounding the mold for a portion of the length of the mold 76. Bin 78 acts to funnel the resin charge 72 into the feeding mechanism 74 which in turn leads into the mold 76. Cooling fluid is continually passed through the jacket 80 as indicated by the arrows 82 to cool the surface of the mold 76. The core rods 78 extended longitudinally of the mold 76 are capable of movement relative to the mold 76 as indicated by the arrow 84. Mold 76 is preferably cylindrical in shape having an end closed by plate 86 and the opposite open; however, mold 76 can be square, round, rectangular or other shape if desired. Movement of the core rods 78 may originate in a second extrusion apparatus (not shown) by which the core rods 78 are formed justp rior to entering the mold 76 through the companion clearance apertures in the end plate 86 illustrated in FIG. 12.

FIG. 13 illustrates the specific configuration of the core rods 78 in cross-section; however, other configurations may be used as desired. As the core rods 78 ultimately provide for the conductors 50 of the

coupling elements

22, 24, the core rods 78 can have cross-sectional sizes and shapes such as those aforementioned and will be circumferentially spaced apart and arranged in a plurality of coaxial circular sets.

The method of utilizing the apparatus illustrated in FIGS. 12 and 13 for fabricating the first embodiment of the electrical connector comprises a first step of continuously feeding a resin charge 72 at a first rate into the elongated mold 76 adjacent the end plate 86 by means of the feeding mechanism 74. Secondly, the core rods 78 are continuously moved through said mold in the direction of arrow 84 at a second rate. Thirdly, coolant is passed through the jacket 80 as indicated by the arrow 82 to cool the mold intermediate the position 81, at which the resin charge enters the mold 76, and the open end of the mold 76 so as to solidify the resin charge adjacent the open end. The resin charge enters the mold 76 at a third rate. Fourthly, the first, second and third rates are controlled so that the resin charge remains plastic for a sufficient length of time to fill completely the mold 76 between the end plate 86 and a solidified portion of the resin adjacent the open end of mold 76 (not shown) to eliminate all bubbles and other voids in the plastic resin charge before the resin charge solidies. The solidiiication of the resin charge must also be at a rate so that it will secure to the core rods 78 and move therewith through the mold 76 at the same rate as the core rods 78. Fifthly, a solidified resin charge is continuously extracted from the mold 76 in the form of a rod of insulating material with a plurality of core rods secured therein. As a sixth step, this rod is cut into segments having opposite ends and the desired length. Such a rod segment is illustrated in FIG. 9 and indicated by the numeral 83. As shown, the core rods 78 and the solidified resin form an integral structure. Rod segments 83 are then placed in a lathe, a screw machine or similar device, and as a seventh step, one of the ends of each rod segment 83 is turned to form a plurality of coaxially cylindrical steps, such as 38, 40, and thereby expose the surface of the core rods 78 to provide a surface onto which wires may be soldered or welded as above described. As an eighth step, the opposite end of each rod segment is turned in similar fashion to form either a male or a

female coupling portion

32 or 34, respectively, having a plurality of step portions which are equal in number to the number of coaxial and cylindrical step portions of the opposite end. The number of step portions at both ends is determined by the number of coaxial sets in which the core rods 78 are arranged. This second turning operation also forms the

detent configurations

52, 54, 56 of the step portions of the

coupling portions

32, 34. The final step comprises forming a cavity such as that indicated by numeral 58 (FIG. 6) by means of a drilling, boring or a similar operation under each of the core rods '78 adjacent to the distal ends of the plug and

socket portions

32, 34. As is above obvious, the core rods 78 must be formed of conducting material, preferably one of these materials mentioned above, and the resin charge must form an insulating material after solidification, preferably one of those plastic materials abovementioned and described.

Referring now to FIGS. 14 and 15, an apparatus for performing a method of fabricating the second embodiment of electrical connectors of this invention is diagrammatically illustrated. In many respects this second apparatus is similar to that shown in FIGS. 12 and 13 as indicated by the like reference numerals that have been assigned to like parts. Generally, the only ditference in the apparatus for performing the second method of this invention from that shown in FIGS. 12 and 13 is that the cooling jacket 80 extends substantially the entire length of the mold 76. Similarly to FIG. 13, FIG. 15 shows in cross-section a configuration of the core rods 78 in an arrangement of coaxial sets circumferentially and equally spaced apart. Further, this second method of this invention is identical to the first method except that the core rods remain stationary and the apparatus extrudes a rod of insulating material having passageways 26 extending therethrough rather than the core rods 78 above-mentioned. In this second method, the rst rate of charging the resin into the mold 76 and the rate of cooling the mold 76 by means of the jacket 80 need only be controlled relative to each other to provide that the mold 76 is adequately filled without voids. The extruded rod is also extracted from the mold 76 and cut into segments of desired length and turned at the opposite ends thereof in identical manner to that above-described. However, during the turning operation which forms the step portions at the terminal end 30 of both the male and

female coupling elements

22, 24, the annular grooves 64 are also formed. The conductors 50a and Stib are thereafter inserted through the passageway 26 in a final assembling step resulting in

coupling elements

22, 24 as illustrated in FIGS. 7 and 8 and above-described.

In operation, since the actual area of contact of each individual conductor 50 as shown in the drawings is arcuate, it is apparent that a much greater area of actual contact between mated male and female coupling elements 22, 2d prevails over other known connector concepts. Because of the unique method of insuring intimate engagement between the male and female coupling elements, even though a connector assembly may contain a relatively large number of conductors, proper electrical connection between the respective male and female contacts is always assured.

Of extreme value in this direction is the fact that the conductors 5t), Stia, Stlb are protected on the bottoms and sides thereof by the

connector portions

44, 46. If the connector part should be dropped, the chances are quite remote that the conductors 50 will be bent. Since such contacts in the miniature connectors are extremely small, corresponding to No. 34 gauge wire or gauges even smaller than this, it is obvious that a slight bump or touching with another object can bend a conductor 50. However, in the design of this invention, the conductor 50 is protected on three sides by the

step portions

44, 46 such that rough handling or bumping of the conductors 50 can be tolerated without any material danger of producing any damage. If such damage should occur, the second embodiment of this electrical connector permits the individual conductors to be replaced. Thus, the rnale and female parts of the electrical connector assembly of this invention can be reliably connected and disconnected :many times with full and complete assurance that all of the conductors will properly mate. Further, periodic replacement of the conductors Stia and 50]; of the second embodiment of the electrical connector of this invention will assure satisfactory performance of the connector for an indefinite period.

Statistics within the industry support the fact that a considerable percentage of existing problems associated with connectors and terminations are a result of damaged conductors which this concept, as disclosed, avoids.

While the

coupling elements

22, 24 are described herein to have terminal ends 30 and plug and

socket portions

32, 34, respectively, at the opposite end 2S, it is within the scope of this invention to provide a male coupling having plug portions 32 adjacent ends 28, 30 or a female coupling having socket portions 34 adjacent ends 28, 30. It is further within the scope of this invention to provide a spacer having a plug portion 32 adjacent end 28 and a socket portion 34 adjacent end 30.

While there have been described above the principles of this invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.

What is claimed is:

1. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent said closed end, cooling said resin charge intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to till said mold before said resin charge solidifies, continuously extracting the solidified charge from said mold as a rod of insulating material, cutting said rod into segments having opposite ends and a predetermined length, turning one of said ends of each of said-segments thereby to form a plurality of coaxial cylindrical steps equal in number to said sets, and turning the other of said ends of each of said segments thereby to form an equal number of coaxial cylindrical steps as said one end.

2. The method of claim 1 wherein said core rods are conductors and are continuously being fed through said mold and extracted with said solidified charge.

3. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent said closed end, cooling said resin charge intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to ll said mold before said resin charge solidies, continuously extracting the solidified charge from said mold as a rod of insulating material, cutting said rod into segments having opposite ends and a predetermined length, turning one of said ends of each of said segments thereby to form a rst stepped diameter end on said segments having a plurality of first cylindrical step portions equal in number to said sets, and turning the other of said ends of each of said segments thereby to form a second stepped diameter end on said segments having a plurality of second cylindrical step portions equal in number to said rst step portions, each of said rst and second step portions having radially outwardly facing surfaces.

4. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent said closed end, cooling said resin charge intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to fill said mold before said resin charge solidifies, continuously exltracting the solidified charge from said Imold as a rod of insulating material, cutting said rod into segments having opposite ends and a predetermined length, turning one of said ends of each of said segments thereby to form a first stepped diameter end on said segments having a plurality of first cylindrical step portions equal in number .to said sets, and turning the other of said ends of each of said segments thereby to form `a second stepped diameter end on said segments having a plurality of second cylindrical step portions equal in number to said first step portions, each of said first and second step portions having radially inwardly facing surfaces.

5. A method of fabricating connector parts comprising the steps of continuously extruding a rod of insulating material, continuously forming a plurality of passages in said rod as it is being extruded, cutting the rod into segments having opposite ends and the desired length, turning one of said ends of each of said segments an amount sufficient to penetrate the cross-sections of predetermined ones of said passages to expose longitudinal end portions thereof, thereby to form at least one exterior and coaxial cylindrical step, and turning the other of said ends of said segments thereby to form an equal number of coaxial cylindrical steps as said one end.

6. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, cooling said mold intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to fill said mold before said resin charge solidifies, continuously extracting the solidified resin charge from said mold as a rod of insulating material, said rod having a plurality of longitudinal and parallel passageways therein formed by said core rods, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of said segments to form an annular detent groove spaced from said one end and a plurality of exterior and coaxial cylindrical steps which communicate with said passageways and are equal in number to said sets, turning the other of said ends of said segments thereby to form an equal number of coaxial cylindrical steps as said one end, and positioning conductors having a detent thereon in said passageways with said detent in said groove.

7. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, cooling said mold intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to fi11 said mold before said resin charge solidifies, continuously extracting the solidified resin charge from said mold as a rod of insulating material, said rod having a plurality of longitudinal and parallel passageways therein formed by said core rods, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of said segments to form an annular detent groove spaced from said one end and a plurality of first coaxial cylindrical step portions which are equal in number to said sets and which communicate with said passageways, turning the other of said ends of each of said segments thereby to form an equal number of second coaxial and cylindrical step portions as said one end, said second step portions having radially outwardly facing surfaces, and positioning conductors having a detent thereon in said passageways with said detent in said groove.

8. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, cooling said mold intermediate said position and said open end at a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sufficient to fill said mold before said resin charge solidifies, continuously extracting the solidified resin charge from said mold as a rod of insulating material, said rod having a plurality of longitudinal and parallel passageways therein formed by said core rods, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of said segments to form an annular detent groove spaced from said one end and a plurality of first coaxial cylindrical step portions which are equal in number to said sets and which communicate with said passageways, lturning the other of said ends of each of said segments thereby to form an equal number of second coaxial and cylindrical step portions as said one end, said second step portions having radially inwardly facing surfaces, and positioning conductors having a detent thereon in said passageways with said detent in said groove.

9. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and -a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, continuously moving said core rods through said mold at a second rate, cooling said mold intermediate said position and said open end at a third rate thereby to solidify said resin charge adjacent said open end, controlling said first, second, and third rates so that said resin charge remains plastic for a time sufiicient to fill said mold before said resin charge solidifies and said resin charge solidifies at a rate so that said resin charge secures to said core rods and moves through said mold at the same rate as said core rods, continuously extracting the solidified resin charge and said core rods from said mold as a rod of insulating material with said core rods being secured in said rod, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of said segments to form a plurality of coaxial cylindrical steps which communicate with said core rods and are equal in number to said sets, turning the other of said ends of said segments thereby to form an equal number of coaxial cylindrical steps as said one end, and forming a cavity under each core rod adjacent to said other end.

10. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, continuously moving said core rods through said mold at a second rate, cooling said mold intermediate said position and said open end at a third rate thereby to solidify said resin charge adjacent said open end, controlling said first, second, and third rates so that said resin charge remains plastic for a time sufficient to fill said mold before said resin charge solidiiies and said resin charge solidiiies at a rate so that said resin charge secures to said core rods and moves through said mold at the same rate as said core rods, continuously extracting the solidified resin charge and said core rods from said mold as a rod of insulating material with said core rods being secured in said rod, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of each of said segments to form a plurality of first coaxial cylindrical step portions Which communicate with said core rods and are equal in number to said sets, turning the other of said ends of each of said segments thereby to form an equal number of second coaxial and cylindrical step portions as said one end, said second step portions having radially outwardly facing surfaces, and forming a cavity under each core rod adjacent to said other end.

11. A method of fabricating connector parts comprising the steps of continuously feeding at a first rate a resin charge into an elongated and cylindrical mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in a plurality of coaxial circular sets and in parallelism with each other, said core rods in each set being spaced circumferentially equally apart, said charge entering said mold at a position adjacent to said closed end, continuously moving said core rods through said mold 'at a second rate, cooling said mold intermediate said position and said open end at a third rate thereby to solidify said resin charge adjacent said open end, controlling said first, second, and third rates so that said resin charge remains plastic for a time suiiicient to ll said mold before said resin charge solidifies and said resin charge solidilies at a rate so that said resin charge secures to said core rods and moves through said mold at the same rate as said core rods, continuously extracting the solidified resin charge and said core rods from said mold as a rod of insulating material with said core rods being secured in said rod, cutting said rod into segments having opposite ends and the desired length, turning one of said ends of each of said segments to form a plurality of first coaxial cylindrical step portions which communicate with said core rods and are equal in number to said sets, turning the other of said ends of each of said segments thereby to form an equal number of second coaxial and cylindrical step portions as said one end, said second step portions having radially inwardly facing surfaces, and forming a cavity under each core rod adjacent to said other end.

12. A method of fabricating connector parts comprising the steps of continuously feeding a resin charge into van elongated mold having an open end, an opposite closed end, and a plurality of spaced-apart core rods arranged longitudinally of said mold and in parallelism with each other, solidifying said resin adjacent said open end, continuously extracting the solidified resin charge from said mold as a rod of insulating material having axial extending passageways formed by said core rods, cutting said rod into segments having opposite ends and the desired length, exposing an axially extending portion of said passageways adjacent to one of said ends of said segments, and substituting conductors for said core rods.

13. A method of fabricating connector parts comprising the steps of continuously feeding a resin charge into an elongated mold having an open end, an opposite closed end, and a plurality of spaced-apart core rods arranged longitudinally of said mold and in parallelism with each other, said core rods being conductive, continuously moving said core rods through said mold, solidifying said resin adjacent to said open end as a rod of insulating material having said core rods secured therein, continuously extracting said rod and said core rods from said mold, cutting said rod into segments having opposite ends and the desired length, exposing an axially extending portion of said core rods adjacent to one of said ends of said segments and forming a cavity under each core rod adjacent said one end.

14. A method of fabricating connector parts comprising the steps of continuously extruding a rod of insulating material, continuously forming a plurality of passages in said rod as it is being extruded, cutting the rod into Segments having opposite ends and the desired length, and turning one of said ends of each of said segments an amount suflicient to penetrate the cross-sections of predetermined ones of said passages to expose longitudinal end portions thereof, thereby to form at least one coaxial cylindrical step.

15. A method of fabricating connector parts comprising the steps of feeding at a lirst rate a resin charge into an elongated mold having an open end, an opposite closed end, and a plurality of axially extending core rods arranged in at least one coaxial circular set, said core rods in said at least one set being parallel to each other and spaced circumferentially apart, said charge entering said mold at a position adjacent said closed end, cooling said resin charge intermediate said position and said open end lat a second rate thereby to solidify said resin charge adjacent to said open end, controlling said first and second rates so that said resin charge remains plastic for a time sutiicient to fill said mold before said resin charge solidifies, extracting the solidified charge from said mold as -a rod of insulating material, cutting said rod into segments having opposite ends and a predetermined length, turning one of said ends of each of said segments thereby to form at least one coaxial cylindrical step equal in number to said at least one set thereby exposing said at least one set.

References Cited UNITED STATES PATENTS 2,749,526 6/1956 Petersen 339-61 3,118,713 1/1964 Ellis 339-176 X 3,218,599 11/1965 Winkler 29-155.55 X 3,229,137 1/1966 McCarty 29-155.53 X 3,235,832 2/1966 Buchanan et al. 339-176 3,333,232 7/1967 Patton 339-182 JOHN F. CAMPBELL, Primary Examiner.

C. E. HALL, Assistant Examiner.

U.S. Cl. XR.