Polarizing Means For Mateable Units Such As Electrical Connectors

Abstract

Polarizing means for mateable units or parts, such as the separable plug and receptacle units of an electrical connector, said means comprising readily removable and replaceable complementary elements selectively oriented and mateably positioned in said units wherein all of said elements may be substantially of identical construction.

Description

This invention relates to means for polarizing or selectively matching separable mateable parts or units, such as electrical connector plug and receptacle units.

One of the objects of the present invention is the provision of novel means in combination with separable mateable units for obviating the erroneous or inadvertent mating or coupling of units which are not intended to be mated or joined.

Another object of the invention is to provide novel simplified polarizing means adapted to be selectively and adjustably positioned in a large number of otherwise similar or identical parts or units for distinguishing the latter from one another.

Still another object is to provide novel polarizing means of the above character whereby a substantially large number of different polarization configurations or arrangements is made possible with an equal or smaller number of structurally different parts of simple construction than has been heretofore possible with prior known devices.

A further object is to provide novelly constructed identical polarizing elements which may be readily installed in the pairs of separable units in a plurality of selective orientations relative to said units and in combination therewith and with each other.

A still further object is to provide novel polarizing means for separable units which comprises a plurality of mating polarizing elements or inserts which are securely retained in the units and yet readily individually removable for indexing relative to the unit and to each other for varying the polarizing arrangement thereof.

The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

FIG. 1 is a front elevation view with parts broken away and partly in section of separable electrical connector units in mated relation with polarizing means according to the invention, the sections of the units being taken on lines 1--1 of FIG. 2, but with the polarizing elements arranged as seen in FIG. 4;

FIG. 2 is a fragmentary exploded isometric view of mateable end portions of the separable units of the connector of FIG. 1, said units being shown with the engageable faces thereof at right angles to each other;

FIG. 3 is a detail isometric view on an enlarged scale of a polarizing element or insert;

FIG. 4 is a fragmentary top plan view of the lower connector unit of FIG. 1 with the polarizing elements positioned as shown in FIG. 1;

FIG. 5 is a view like FIG. 4 of the same connector unit with the polarizing elements positioned as shown in FIG. 2; and

FIG. 6 is a similar view showing the polarizing elements in the upper connector unit as viewed in FIG. 2 arranged to complement and mate with the elements shown in FIG. 5.

In the single embodiment of the invention illustrated in the drawings, by way of example, the novel polarizing elements are shown in novel combination with the main body portions of the plug and receptacle units of a pin and socket-type electrical connector. It will be understood, however, that the use of the invention is not limited to electrical connectors.

The connector chosen for purpose of illustration is of the so-called rack and panel type. Large numbers of such connectors of similar and even identical construction and appearance are often employed in computers, control systems and like installations. By way of example, in some installations, the connector halves of one type, commonly known as receptacles, are stacked and permanently mounted on panels or the like, and the connector halves of the other type, commonly known as plugs, are connected to flexible conductors or cables and are selectively mateable with respective ones of the fixedly mounted receptacles. It is essential that the plugs and receptacles be correctly matched and mated to avoid malfunctioning of and severe damage to the apparatus with which the same are associated.

The novel polarizing means contemplated by the present invention makes it possible to achieve the desired end in an installation of considerable size, while utilizing connector or comparable mateable units and polarizing inserts therefor which are of identical construction and appearance, thereby permitting economical production and constructing of both the units and the inserts. For a given pair or set of separable units, the polarizing means of the invention consists of a plurality of novelly constructed pluglike inserts which are installed with a force or press fit in aligned recesses or seats in the body portions of said units. The seats and inserts are of such construction and shape that the inserts may be removed, angularly indexed and reinserted and may thus be selectively disposed in a plurality of different positions in the seat. The outer end or stem portions of aligned polarizing inserts of mated units are shaped to complement and hence, mate or mesh with each other when such inserts are correctly oriented or indexed relative to each other. For each position of such an insert in one of two mateable units, there is a complementary position for the opposed or corresponding insert in the other unit. If any one insert is not thus complementally positioned or oriented, interference results to prevent coupling of the units.

The specific embodiment of the invention illustrated in the drawings comprises a connector receptacle unit 10 and a connector plug unit 11 separable mateable with each other. The receptacle unit as shown includes a body 12 of substantially rigid insulating material in which a plurality of pin contacts 14 may be mounted in any suitable manner known to the art. Pins 14 extend into a cavity 15 in the face of body 12 and bolt holes 16 are provided for mounting the receptacle unit. The connector plug unit 11 similarly includes a body portion 17 of substantially rigid insulating material with a raised face portion 18 that fits within the cavity 15 of the receptacle. A plurality of socket contacts 19 of known construction are suitably mounted in any known manner in plug body 17 to receive pin contacts 14. Suitable means, such as stud bolts 20, may be used to anchor plug 11 in mated or coupled position with receptacle 10.

In the illustrated embodiment the means for distinguishing one receptacle unit 10 or a plug unit 11 from otherwise similar or identical receptacle and plug units, respectively, comprises a plurality of polarizing inserts 21 seated side-by-side in a rectangular recess 22 in each said unit, the recesses 22 of mated plug and receptacle units as seen in FIG. 1 being in substantial alignment or registry. Except for small manufacturing tolerances, all of the pluglike inserts 21 are preferably identical, each consisting of a base portion 23 of square transverse cross section at one end and a portion of reduced transverse rectangular cross section forming a stem 24 extending from the base portion and spaced laterally at least a short distance from a plane which bisects the base portion 23 longitudinally and contains the longitudinal axis thereof. The stem 24 as shown forms an extension from one end of the base 23 and is of rectangular transverse section, the width of the shorter sides thereof being somewhat less than one-half the width of the corresponding sides of the square base portion.

Inserts 21 are novelly secured in recesses 22 to provide sufficient insurance against their falling out or being accidentally or inadvertently removed when the units 10 and 11 are not mated and to permit at the same time the manual removal, angular indexing and reinsertion of each insert to vary the polarizing pattern. For this purpose inserts 21 are made of a substantially rigid yet slightly resilient material, such as Nylon, and are provided with integral longitudinally extending ribs 26 or the equivalent thereof on the sides of base portion 23. The ribs in transverse cross section are preferably in the form of a semicircle or smaller segment, all being of uniform height and depth. The dimensions of recesses 22, base portions 23 and segmental ribs 26 are calculated to result in an interference or press fit of about one-thousandth up to a few thousandths of an inch, preferably about two-thousandths inch. In order to obviate interference between the ribs 26 on adjacent sides of the pair of inserts 21 in each recess 22, one rib is located on a corresponding half of each side of base 23 of each insert. Thus, as viewed in FIG. 3, a rib is located about centrally of the left-hand half of each side of the base portion of the insert. Each insert may thus be indexed 90.degree., 180.degree. and 270.degree. from any given position without interference between ribs 26 on adjacent inserts.

In view of the practical desirability of allowing small manufacturing tolerances for the dimensions of the various assembled parts and the accumulation of such tolerances in a finished assembly, it may be desirable to provide ridges, ribs or the like on the walls of recesses 22 which complement ribs 26 on inserts 21. Thus, similar semicylindrical or segmental ribs 27 projecting from the walls of that portion of recess 22 which surrounds base 23 may be located to alternate with ribs 26 on the base portions of inserts 21. The bases 23 of the inserts have a press or interference fit within ribs 27.

As will be apparent from FIG. 1, the combined depths of aligned recesses 22 in mated units 10, 11 is somewhat greater than the combined overall length of the mating or complementally positioned inserts 21, 21 to provide suitable clearance between the ends of stems 24 and the outer end surface 28 of base portions 23 adjacent thereto. Adequate clearance is also provided between the adjacent faces of stems 24 and between said stems and the walls of the recesses 22 into which they extend to assure proper mating of the units 10 and 11 without stressing any of the mating parts. In the event any insert 21 in receptacle unit 10, for example, is not properly positioned to mate with the opposed insert in a plug unit 11, the outer or free ends 29 of the stems thereof will engage one another and prevent mating of the units and hence, the engagement of contacts 14, 19 carried thereby.

To assist in the proper positioning of the polarizing inserts in two mating units, the positions for the stems 24 in recesses 22 may be assigned numbers (or letters) as in FIGS. 2, 5 and 6. Each number (or letter) on the receptacle 10 should complement the same number on the plug 11. Accordingly, when the stem of an insert in the receptacle 10 is indexed to position 1, for example, the stem of the mating insert in the plug unit 11 should also be indexed to position 1. In the drawing the positions at opposite ends of the recess on receptacle unit 10 (FIG. 6) are assigned the numbers 2 and 7. The central positions are assigned numbers 4 and 5, and the remaining numbers are assigned to positions at the longer sides of the rectangular recesses.

It will thus be seen that each square insert 21, 23 may be angularly indexed to locate the stem thereof in any of four different positions for each of the four different positions of the second insert in the same recess 22. Accordingly, 16 different polarizing arrangements or patterns may be accomplished with the polarizing means thus far described. By duplicating said polarizing means at the other ends of connector bodies 12 and 17 as indicated at 30, it is possible to distinguish 256 sets of connector units from each other. For each of the 16 patterns at one end there will be 16 different patterns available at the other end. When more different patterns are required, more than two inserts may be arranged in suitable recesses at one or both ends of the bodies 12 and 17.

Claims

What is claimed is:

1. Apparatus comprising first and second mateable units having therein opposed aligned recesses of transverse rectangular cross section, and polarizing means for controlling the mateability of said units comprising a like plurality of pluglike inserts side-by-side in each said recess, each said insert having a base portion of substantially square transverse section seated in the inner end of a said recess and a stem portion extending axially from the outermost end surface of said base portion, said stem portion having a transverse section somewhat less than one half the transverse section of said base portion and being spaced from a line bisecting said end surface, whereby said units are mateable only when each said insert in the first unit is complementally oriented with the oppositely disposed insert in the second unit.

2. Apparatus as defined in claim 1 wherein all of said inserts are of substantially identical construction.

3. In a separable electrical connector comprising a receptacle unit and a plug unit, said units including rigid insulating bodies carrying mateable pin and socket contacts, polarizing means for said units comprising a plurality of pluglike inserts seated in a recess of rectangular section in each of said units, said recesses being in alignment and oppositely disposed when the pin and socket contacts are mated, each said insert having a base portion and a reduced stem portion and said inserts being slidable into said recesses with an interference fit between said base portions and the walls of the recesses whereby the inserts are removably secured in said recesses.

4. An electrical connector as defined in claim 3 wherein the transverse cross section of the stem portion of an insert is somewhat less than half the corresponding cross section of the base portion and said stem portion is positioned at one side of the longitudinal axis of said base portion.

5. An electrical connector as defined in claim 3 wherein each said insert has a longitudinally extending rib on and displaced from the center of each side of the base portion thereof, said ribs being generally evenly spaced about the periphery of the base portion and of substantially even height.

6. An electrical connector as defined in claim 5 wherein the ribbed base portions of the polarizing inserts have a compression fit within said recesses.

7. An electrical connector as defined in claim 6 wherein the inserts are made of a slightly resilient material, such as Nylon.

8. An electrical connector as defined in claim 5 comprising inwardly projecting, longitudinally extending ribs on the walls of the recess arranged to alternate with the ribs on the inserts in said recess and to engage the sides of the base portions thereof.

9. An electrical connector as defined in claim 8 wherein the ribs on the recess walls have an interference fit with the base portions of said inserts.

10. An electrical connector as defined in claim 5 wherein said ribs on adjacent sides of adjacent inserts in a said recess are offset one from the other irrespective of the angular orientation of the inserts.

11. Apparatus comprising first and second separable mateable units having therein opposed aligned recesses of transverse oblong rectangular cross section and polarizing means for controlling the mateability of said units comprising a plurality of pluglike inserts seated in each said recess, said inserts being of substantially identical construction, each comprising a base portion and a reduced stem portion positioned at one side of the longitudinal axis of the base portion, said inserts and recesses having ribs thereon which alternate around the periphery of the recess to provide an interference fit for the inserts in the recess.