US3551877A - Electrical connector - Google Patents

Description

Dec. 29,1970 w TELMQSSE ETAL, 3,551,877

' ELECTRICAL CONNECTOR Filed Nov. 20, 1968 Fig. .2

Fig.3

E6 ww m w TL R mm? o v v v T WM M United States Patent US. Cl. 339-62 Claims ABSTRACT OF THE DISCLOSURE An electrical connector has an L-shaped pin with two legs held by an insulating body. The body is provided with a first hole establishing a press fit with the protruding end of one leg of the pin. The other leg protrudes from a second hole in the body. Further provided the body is an entrance slot extending inwardly toward the first and second holes from a side of the body opposite the first hole. The slot makes an interference lit with the pin, whereby the connector can be assembled by inserting one leg of the pin first through the slot toward the first hole, meanwhile applying force to the other leg of the pin to pass the pin through the slot for subsequent reception and secure retention of the legs in their respective holes.

This invention relates to electrical connectors, especially those having an insulating body from which end portions of electrically conductive pins protrude. The invention is applicable, however, to connectors having male and/or female terminal conductors held by an insulating body.

Connectors of the type set forth are adapted to be readily connected to mating connectors whereby a number of electrical circuit connections can be quickly, securely and effectively made or broken at one time.

According to the present invention an improved connector and method of making the same is provided. This is accomplished by forming a terminal conductor with legs diverging from the bend at which the legs are joined, also an insulating body of yieldable plastic having one hole making a press fit with one such leg therein and another hole for receiving the other leg of the same pin with clearance therebetween. A passage in the insulating body provides access for each pin to the mentioned holes from the opposite side of the body; and it includes an entrance slot making an interference fit with the pin inserted therethrough. During manual assembly, finger pressure is sufficient to press fit one leg endwise in its hole, and to pass the other leg through the slot so as to make a sidewise entrance into the other hole, the interfering structure at the slot thereafter retaining the pin in its holes.

The various objects, features and advantages of the invention will appear more fully from the detailed description which follows, taken in connection with the accompanying drawing, in which:

FIG. 1 is a partly exploded perspective view of an electrical connector embodying the invention, partly shown in section;

FIG. 2 is a plan view of the connector of FIG. 1, but omitting the pins; and

FIG. 3 is a rear elevational view of the connector of FIG. 2.

As illustrated, a preferred form of the invention is embodied in a male connector 10 comprising a body 12 and one or more pins 14 serving as terminal conductors. Preferably there are a multiplicity of generally L-shaped pins 14, each having two legs 16, 18 with end portions thereof protruding from the body 12.

The pins 14 are made of suitable electrically conduc- 3,551,877 Patented Dec. 29, 1970 tive material. And although the invention is not so limited, the material is preferably Phosphor bronze wire of circular cross section and of high tensile strength, i.e. with a desirable minimum tensile strength of 115,000 p.s.i. As an example, an Lshaped pin 14 of a miniature connector may have a .340 inch long leg 16 and another leg 18 .210 inch long, made from a length of .040 inch diameter Phosphor bronze spring material, with a right angle .030 inch radius bend 20 between legs, and silver plated over its entire surface to a minimum .0002 inch thickness. The legs 16, 18 can be adapted for some applications to be at other than a right angle inclination to one another, it being a general requirement that they be in divergent relationship relative to the bend 20 where they are joined.

It is desirable for each extreme end of the legs 16, 18 of pin 14 to be tapered to a flat circular end surface having a diameter which is a fraction of the diameter of the solid wire stock. A pin 14 as specified may be used for 7.5 ampere, 40 volt D.C. service.

Obviously, a non-protruding female terminal conductor can be made of hollow or tubular stock instead of solid wire if it is desired to make a female connector according to the invention. In a typical male connector 10, however, approximately one-half the length of each of the legs 16, 18 will protrude from the body 12, while the remainder of each pin 14 is secured in interlocking formation with the body 12.

The body 12 is made of suitable electrically non-conductive material, polypropylene being the material of choice for mass production manufacture because it is a strong, hard, moldable, plastic insulating material. As shown, the body 12 is an elongated member of generally rectangular transverse cross section, e.g. .300 x .225 inches, with transverse holes and passageways formed therein during molding for the reception and retention of the terminal conductors or pins 14.

As mentioned previously, the present arrangement is a departure from the known practice of molding an insulating body about terminal conductors. More specifically, the present arrangement provides a rugged and dependable connector which can be made by assembly of its components with greater efficiency, accuracy, and economy than was heretofore possible.

According to the invention, the molded body 12 has a horizontal top face or side 22 provided with a longitudinally spaced series of transversely extending upstanding ridges 24 projecting above the adjacent surface areas. In the example, the ridges extend upwardly .025 inch. As is conventional, the ridges 24 divide and shield the areas of the top side 22 lying between them whereby the sites provided for eventual connection of the mating terminals are sheltered one from the other.

As best seen in FIG. 1, the leg 18 of each pin 14 is adapted to have an end portion thereof extend from a vertical hole 26 in the top side 22 of body 12. The leg 18 extends upwardly to a level above the ridges 24. There are a longitudinally spaced series of such holes 26. The front face or side 28 of the body 12 is a longitudinally extending, vertical planar surface provided with a series of horizontal holes 30, spaced as are the holes 26, and adapted to establish a press fit with the other leg 16 of each pin 14. Wher a pin 14 is provided, an end portion of its leg 16 protrudes in horizontal direction from the corresponding hole 30 so as to be normal to the surface of the bodys front side 28.

In order to establish a press fiit between the holes 30 and the legs 16, the holes 30 are made .038 to .040 inch in diameter and the legs 16 after silver plating have a diameter in the range of between .0400 and .0415 inch in the illustrated embodiment. More generally a press fit is established when the leg 16 is the same size as the hole 30 or slightly larger.

The horizontal length of hole 30 is for most of the nonprotruding length of the leg 16. However, access for leg 16 to hole 30 from the vertical face opposite face 28 at the back of the body 12 may be through a horizontal access passage 34 of much larger dimension than the pin diameter, e.g., .050 inch wide, where the passage 34 is aligned with the hole 30.

Assuming that the vertical leg 18 of pin 14 is in the same size range as the leg 16, the hole 26 may have a diameter in the range of between .042 and .044 inch. In general, therefore, hole 26 is a clearance hole which is slightly larger than the leg 18 it receives.

From the foregoing it can be seen that the horizontal leg 16 is positioned by placing it in horizontal attitude and inserting it into a loosely fitting portion of access passage 34 leading to the hole 30. By continued horizontal movement of leg 16 toward the front side 28 of the body 12, the leg 16 will have an end portion thereof protruding from the front of the body and an inner portion thereof adjacent the bend 20 snugly fitted into the hole 30.

In order that the pin 14 will be securely retained in the body 12, the horizontal access passage 34 is provided with a narrow slot 36 which extends through to the top side 24 of the body and makes an interference fit with the vertical leg 18 of the pin. For example, the slot 36 preferably is .033 to .036 inch high and presents a .025 to .027 inch wide passageway to the .0400 to .0415 inch diameter pin, thus requiring the application of horizontal force to the leg 18 in order to force it through the slot 36 into hole 26 and at the same time press fit the leg 16 into hole 30. The internal wall structure of the plastic body 12 defining the slot 36 yieldingly resists passage of the leg 18 therethrough; but once the parts are assembled in final position as shown in FIG. 1 they are securely retained thus. This retention is accomplished as the narrowly spaced wall structure defining slot 36 resumes original shape and bears against the leg 18 with the inner edges thereof exposed by the hole 36.

It can now be appreciated that the press fit between the hole 30 and leg 16 positions the pin 14 and holds it against vertical movement from position, whereas the interference fit between the hole 26 and leg 18 also positions the pin and holds it against horizontal movement from position.

The horizontal force to the pin 14 required during hand assembly can be conveniently applied with finger pressure to the protruding end portion of the leg 18.

From the foregoing it can be seen that a connector can be made according to the invention by molding the insulating body 12 of yieldable plastic with a horizontal hole 30 in the front side 28 adapted to press fit the horizontal leg 16. At the time of molding the body 12, there is formed in the top side 22 a vertical hole 26 which is slightly larger than the vertical leg 18. Further provided is an access passage 34 including a slot 36 extending from the top side 22 and the back side 32 inwardly of the body so the slot 36 makes an interference fit with the leg 18. There is one continuous and cavernous passageway comprising the holes 26, 30 and passage 34, all lying in the same vertical plane, for each pin 14 to be installed in the body 12. Next, the L-shaped pin 14 is inserted, horizontal leg 16 first, and vertical leg 18 upright, through the passage 34 with horizontal thrust applied to the leg 18 as the latter passes through the slot 36. The legs 16 and 18 are then received in their respective holes 30 and 26 and retained therein by the resilient wall structure defining the slot 36.

Although the invention has been described as applied to one specific embodiment of the invention, it is susceptible of changes and variations which will occur to one skilled in the art without departing from the inventive Lil 4 concept, the scope of which is better determined by the following claims.

What is claimed is:

1. An electrical connector comprising a body of electrically non-conductive material and at least one terminal conductor of electrically conductive material held by said body; said conductor including first and second legs having respective one ends thereof joined together, and having respective other ends of said first and second legs extending outwardly of said body in divergent directions passing respectively through first and second faces of said body; said body having a first opening therein at said first face for the reception of said other end of said first leg, and having a second opening formed therein at said second face for the reception of said other end of said second leg; said body having a third face opposite said first face and also having an access passage including an entrance slot formed in said second and third faces; said entrance slot extending inwardly of said body generally toward said first and second openings, said entrance slot having a width narrower than the width of the respective first and second openings and narrower than the thickness of said second leg, and said access passage providing an avenue of entrance to said body for said conductor.

2. An electrical connector according to claim 1 wherein said other ends of said legs have portions thereof protruding from said first and second faces of said body.

3. An electrical connector according to claim 1 wherein a press fit is provided between said first opening and said first leg, and an interference fit is provided between said slot and said second leg.

4. An electrical connector according to claim 1 wherein said conductor is substantially L-shaped, and said second face is disposed between said first and third faces of said body.

5. An electrical connector of the male type according to claim 1 wherein the conductor is a pin of circular cross section slightly larger than said first opening and larger yet than said slot, said body being made of yieldable plastic material.

6. An electrical connector according to claim 1 wherein the conductor is made of silver-plated Phosphor bronze material and said body is made of polypropylene material.

7. An electrical connector according to claim 1 wherein said body is an elongated member of generally rectangular transverse cross section, with a multiplicity of longitudinally spaced first openings in said first face, a multiplicity of longitudinally spaced second openings in said 'second face adjacent said first face, and a multiplicity of said slots extending transverse to the longitudinal extent of said body in alignment with associated first and second openings.

8. An electrical connector according to claim 7 wherein said conductor is a substantially L-shaped member of generally uniform circular cross section intermediate the ends thereof, there being one such connector for each of said slots, each of said first openings being slightly smaller than said connector to provide a press fit therewith, and each of said slots being smaller yet than said first openings to provide an interference fit with said second leg of said connector, said body being made of yieldable plastic material, whereby said connector is assembled to said body by inserting it first leg first through said slot and into said first opening while applying force to said second leg to pass it through said slot into said second opening, each of said second openings holding said connector by said second leg against separation from said body.

9. An electrical connector according to claim 7 further including between each neighboring pair of first openings a transversely extending ridge projecting above said second surface.

10. A method of making an electrical connector wherein a terminal conductor is held by a body of electrically non-conductive material, comprising the steps of:

(a) forming said body with a first circular opening on one face thereof, a slightly larger circular opening in References Cited an adjacent second face disposed at a right angle to UNITED STATES PATENTS said first face, and a slot in said second face and a third face opposite said first face, said slot com- 2984814 5/1961 Scott 339-64 municating through a space smaller in width than 5 FOREIGN PATENTS said first opening with said first and second openings, 1 364 127 5/1964 France 339 17(Lc) (b) providing a generally L-shaped conductor made of electrically conductive material with substantially THER REF NCE uni-form diameter intermediate its ends, and having T l jl h Buggie Inc p c i P div?rgent legs 10 nectors, June 1954, page 18. msertlng Said Conductor one g first through Sald Electronic Design, U.S. Components, Inc., February slot and endwise into said first opening while apply- 1961, page ing force to the other leg of the conductor until said other leg passes through said slot by yielding resist- MARVIN CHAMPION, Primary EXamiIler ance of the wall structure defining said slot and makes 15 LAWRENCE J. STAAB Assistant Examiner a sidewise entrance into said second opening, thepin being thus retained by the edges of said wall structure US. Cl. X.R.

at said second opening hearing on said other leg. 339-156, 221

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