US3067401A - Electrical connector - Google Patents

Description

Dec. 4, 1962 c. R. RHODES 3,067,401

ELECTRICAL CONNECTOR Fi1edJu1y22,1959

CHESTER R RHODES AGENT Uite rates arent Y y 3,967,401` ELECTRICAL CONNECTOR Chester R. Rhodes, 266 W. Stardeil, Whittier, Calif. Filed July 22, 1959, Sel'. No. 823,860* '7 Claims. (Cl. 339-63) My invention relates to a solderless type of electrical connector. It may be fabricated to join only two electrical conductors or a plurality of such individual elements may be mounted to simultaneously secure or release a plurality of electrical conductors.

In electronic equipment and the like numerous separable electrical connections are required between wires, plug-intype' relays, etc. Good electrical connection is necessary and this can be accomplished by a sliding action of theconnecting elements each time the connection'is made. It is also desirable that the restraint resisting a force to separate the connection increase as a function of the magnitude of such a force, that the reliability of the connection not be influenced by temperature nor by vibration, that the connector be relatively inexpensive to manufacture, and that it be separable with simple tools.

-I have been able to meet the above requirements by forming a somewhat ilexible conductor into a loosely woven braid of tubular shape. Wires or other electrical elements to be connected are terminated by cylindrical pins which fit within the woven tube. After the insertion of the pins into the tube any attempt to pull them out,

as by means of the wires attached to the pins, causes the braid to deform to a smaller internal diameter. This causes the pins to be held all the more rmly. This action continues until the structure ruptures at its weakest point, which may well be the wires rather than the connector. On the other hand, if the pins are to be removed from the woven sleeve to break the connection it is only necessary to decrease the length of the sleeve with the fingers, or by means of a simple compressive plier-like 4tool and the pins may be readily released.

Where a plurality of connections are to be made my individual connectors are provided with planar members to hold the circuits as a group, and by employing screws in association with such members all individual connectors may be loosened or tightened at once.

-An object of my invention is to provide an electrical connector having great mechanical resistance to separation by axial tension.

Another object is to provide a connector that assembles with a wiping action of the contact surfaces.

Another object is to provide a connector that is minimally affected by vibration.

Another object is to provide a multiple electrical connector of simple construction. n

Another object is to provide a connector that is relatively inexpensive to manufacture.

Other objects will become apparent upon reading the following detailed specification and upon examining the accompanying drawings, in which are set forth by way of illustration and example certain embodiments of my invention.

FIG. 1 shows a sectional elevation View of an assembled individual connector according to my invention.

FIG. 2 shows an end elevation of the outer woven tubular element alone,

FIG. 3 shows an alternate embodiment of a pin alone,

FIG. 4 shows a top view of a multiple connector,

FIG. 5 shows a side view of the same multiple connector, in partial section, and

FIG. 6 shows a sectional elevation view of a detail of the structure of FIG. 5.

In FIG. l numeral 1 indicates the loosely Woven mesh ice 2 or braid. This lis fabricated of a conductor of electricity, such as any mechanically str-ong worked copper or copper alloy, or this may be an alloy of silver and copper having of the order of'7G% silver. The requirements are; good contact conductivity and freedom from fatigue.

The contact pins from the circuits to be connected make contact through this braid and so the former requirement is obvious. The latter requirement arises from the minor mechanical deformation that occurs when the connector is separated and joined to accomplish disconnection and reconnection. Many thousands of such operations may occur during the extended life of my device and Where this is the case the latter requirement is irnportant.

Braid 1 is attached to annular disks or rings 2 at each end in order that the braid shall not ravel. The attachment may be accomplished by soldering, welding or crimping. As shown in FIG. 2 I prefer to provide a radial slot 3 completely through disks 2. These disks are then formed to present a tight t to the contact pins when these are inserted through the hole thereof. When the pins are inserted the disk is slightly expanded. This is a manufacturing convenience that removes the requirements of close tolerances between the diameters of the pins and the diameter of the hole in the ring.

Pins 4 and 5 form the other mechanical elements to accomplish electrical connection between the two external conductors. These are each provided with an axial hole or equivalent reentrant construction (not shown in FIG. l) to receive external conductors 6 and 7, respectively. In ordinary practice these conductors would merely be soldered into holes in pins 4 and 5. For high temperature applications, or for manufacturing convenience, the wires may instead be Welded or crimped to the pins. Insulating coverings 8 and 9 have been shown on conductors 6 and 7 as illustrative of a most frequent application of my invention. The pins may be fabricated of brass or bronze and may be silver plated, etc. for superior contact performance.

My connector is held together by an external elastic element 10, capable of viscous contraction after elongation. This may be a tubing of silicone rubber. It ts over annular disks 2 with at least some bulge as shown, and is proportioned so as to elongate braid sleeve 1 when the elastic element is relaxed. In this condition the woven braid tightly enfolds the pins and these cannot be pulled out of it. Should this be attempted, the braid grasps the pins even more tightly. This is the normal connected configuration of elements and forces.

When it is desired to disconnect the connection elastic element 10 is shortened axially by pressing the ends together with the ngers of two hands, say; or by accomplishing an equivalent compression with a pair of pliers having U shaped jaws to fit around the external conductor insulations 8 and 9. From what has been previously mentioned it will be understood that the grip of the mesh sleeve will be removed and the pins 4 and 5 may be pulled out of the connector with a small force. v

As an alternatesubstance, elastic element 10 may be certain of the newer plastics, such as foam, styrene or certain exible epoxys having elastic properties; or even Teon may be employed. The function of element 10 is to keep the tubular braid tight around the pins when there is no tension on the conductors by supplying the equivalent of such tension. This need be only a minor force and so a substance not always regarded as a rubber-like material may be employed.

An alternate construction for the pins is shown in FIG. 3. The modification consists of the enlarged portion 12 formed on pin 14. This portion acts as an additional securing means. The tubular braid forms around the ahem/s1 enlarged portion and so the security of the pin in the connector is greater than with the previously described purely cylindrical pin. The position of the enlarged portion along the length of the pin may be any of a number, starting at the free end (to the right in FIG. 3) to relatively toward the conductor end of the pin. The latter end is identified in FIG. 3 by the axial hole 15. When enlarged portion 12 is at the free end on both of the opposed pins in a connector such as shown in FIG. 1, both act to form one portion'of enlarged diameter in the tubular braid. When the enlargements are spaced apart,as in the one example of FIG. 3, two enlarged portions of the braid result.

FIG. 4 shows the top view of a multiple connector and FIG. 5 the elevation thereof. Substantially the same connectors as shown in FIG. 1 are either pressed into suitable holes in a body or central plate 16, or are molded into the same. The latter is preferable. This body is normally formed of a mechanically strong insulator, such as diallyl phthalate 'or an equivalent. This body could be a conductor, since the several individual connectors each have a non-conducting elastic element 18 as a surround, which serves to insulate one from the other. These elastic elements diier Afrom elastic element in that these do not Yextend to the ends of the connector assembly.

In this multiple embodiment I prefer to obtain securing and unsecuring action by means of thumb screws or cap screws 19 for accomplishing this function on one side of the connector and screws 26 on the other-side. This allows separate connection or disconnection on opposite sides. In addition to merely connecting wires with my multiple connector it will be understood that pin type relays may be insertedon the top (or the bottom) of the multiple connector, with wires out the opposite side. Thus, if it is desired to replace one or more relays, one side of theconnector is loosened; if to replace one or more wires, the Other side is loosened. The central plate or body has projecting ends and is identified by numeral'l.v Holes 17 are formed in these ends for mounting the multiple connector as a whole.

.In the multiple connector embodiment two end plates 21 and 22, are employed, into which the ends of the tubu lar braid individual connectors are tightly fitted. The top annular disks 23 may be seen in FIG. 4, which figure corresponds to a multiple version of FIG. 2. Each end plate is providedl with threaded holes to accommodate threads on each screw, as 19, shown in the right-hand partial section in FIG; 5. If the plate is fabricated of a mechanically strong insulator, the threads may be formed y in that material, but a threaded metal insert is to be preferred. It is seen that when the screws are turned in one direction the end plates are forced away from the center plate and when turned in the other direction the reverse is true. The rst (outward) position corresponds to the pins locked in the tubular braid, while the second (compressed) position corresponds to the connectors expanded in diameter and thusthe pins free to be removed. In order thatv the screws remain captive and not become lost I place washers 24 on each and then swage ears 25 beyond on the non-threaded end of the screws to retainv the washers. i

I prefer to mold or to otherwise provide a pair of ribs integral with each end plate. These are identified as 26 and 27 for the upper end plate and 28 and 29 for the lower. Such ribs provide very eifective stiiening. Although the multiple connector will function satisfactorily without precise alignments it is desirable to have each of the relatively rigid members remain in substantially xed shape. It will also be understood that such ribs mayy also be located on the outer sides of the end plates. In such a position they act as battles between one multiple connector and another. Ribs may also be located on both the inside and the outside faces of the end plates, .and may be included on the Vcenter plate 16 is desired.

I also prefer to include a plurality of guide pins 30 for maintaining alignment of the end plates with the central plate or body. Such guide pins are a tight fit in the central plate 16 and sliding fits in plates 21 and 22. Four guide pins have been shown in FIG. 4. Two, lof course, could be used; located at opposite corners of the plates. Also, four screws 19 and four screws 20 may be used at the four corners and only two centrally located guide pins 30 located where screws 19 and 20 arel not located.

It is apparent that my multiple connector can be fabricated for as few as two connections, for eighteen con nections as shown, or for any number up to hundreds of connections. In the latter construction, screws 19 and 20 are included at repeated intervals along the plates. The plates may have any shape and any arrangement of individual connectors thereon.

A further modification of the multiple connector of FIGS. 5 and 4 is shown fragmentarily in FIG. 6. In this embodiment each tubular braid is arranged so as to have a limited amount of lateral self-adjustment. This is to accommodate the pins of a plug-in relay or the like, which pins are lixed in position.

y:Numeral 33 represents a fragment of one end plate. This is drilled to receive a tubular braid 34 and annular disk 35. Above this disk a ring 36 `is pressed into plate .33. The ring is made a tight fit radially in the plate, but axially of the tubular braid 34 sufficient clearance is ar` ranged to allow the annular disk to shift laterally in position. This accommodates any particular mis-positioning of relay pins, which condition is to be expected in ordinary manufacturing or for other reasons.

It will be understood that the axial clearance desired of ring 36 may be determined by the form of the hole in plate 33. A slightly larger diameter hole can be drilled in the upper part of this plate and ring 36 is made slightly larger so that it will tit in the upper part of the hole but not farther down thereinto. A flat-bottomed reamer or an equivalent special tool is employed to obtain a planar face at the bottom of the step in this modified hole.

Should it be desired to enclose the multiple connector of FIGS. 4 and 5, this can be accomplished by providing an outer housing of substantially rectangular shape. Partial enclosure can be accomplished by merely providing ribs toward the central plate on both end plates around the periphery of each. Such ribs may not extend all the way to the center plate because of the variation in distance between the plates during t-he connection and disconnection processes. Very nearly the same result may be obtained, however, by adding ribs on both sides of the central plate but at slightly different positions so that the two sets of ribs on the end plates and on the central plate slide past Veach other when these plates are brought together for disconnection purposes.

Rather than one mounting hole 17 at each end of the body or central plate, two or more such holes may be provided by extending'the' plate into a rectangular shape and forming the holes in thel corners of the rectangle, andsoy on. v

While a selvage at the'end of the woven conductive element 1 has been shown as an attached metal annulus, the selvage can be formed by redundancy in the weaving alone at the ends of this tubular braid.

Also, the expanded portion 12 in FIG. 3 may take the form of a taper along the pin 14, with the taper largest at the right hand end of the ligure.

It is not mandatory that the elastic element 10' overhang the annulus pieces 2 in FIG. 1.

In addition to the modifications that have been detailed above, various other modifications may be made in the arrangement, size, proportions and shapes of the illustrative embodiments shown and also by the substitution of elements from one embodiment to another without departing yfrom the scope of my invention.

Having thus fully described my invention and the manner in which it is to be practiced, I claim:

1. An electrical connector comprising plural hollow elements of conductive Woven braid, an elastic element surrounding each said braid, conductive elements proportioned to it oppositely into said hollow elements, a body having a hole to receive each said elastic element, an end plate disposed on cach side of said body, one end of each said hollow element tightly attached to one said end plate with lateral play, each said end plate having opposed adjustable means bearing onto said body; the recited elements proportioned so that when the plural connector structure is 1in-stressed said conductive elements are free to be withdrawn from said hollow elements and when said opposed means are stressed said conductive elements are held within said hollow elements.

2. A multiple electrical connector comprising plural individual connectors each having a tubular conductive woven braid with annular ends, a resilient tubing closely surrounding said braid, conductive connector pins, said pins proportioned to lit into said braid, a central plate having a hole to separately receive each said tubing, an end plate disposed on each side of said central plate, each end plate having a hole to receive and secure one of said annular ends of each said braid in an alignment perpendicular to said plates, each said end plate having screws threaded into said end plate and bearing onto said central plate in opposition, plural guide pins passing through said plates to maintain said tubular braids in axial alignment; the recited elements proportioned so that when said screws are withdrawn from contact with said central plate said pins are free to be withdrawn from said braids and so that when said screws are tightened against said central plate the braids each grip the pins therewithin.

3. A multiple electrical connector comprising plural individual connectors, each said individual connector having a tubular conductive open mesh woven braid with annular ends, a resilient tubing closely surrounding each said braid, conductive pins attachable to electrical elements to be connected, said pins proportioned to tit into each end of said braid, a central plate having a hole to receive each said resilient tubing in spaced relation, an end plate disposed on each side of said central plate in planes parallel to the plane of said central plate, each end plate having a hole to tightly receive one of said annular ends of each said braid in alignment perpendicular to the planes of said plates, each said end plate having plural captive screws threaded into said end plate and bearing onto said central plate in aligned opposing manner, plural guide pins fastened in said central plate and having a sliding t in said end plates to maintain each said tubular braid in axial alignment; the recited elements proportioned so that when the multiple connector structure is unstressed the pins are free to be withdrawn from said braids because of the relaxed length of said resilient tubing but that when said screws are tightened said braids are each elongated to firmly grip the pins therewithin.

4. The electrical connector of claim 1 in which said proportioned conductive elements are shaped with an enlarged cross-sectional area for a portion of the axial length thereof, said conductive woven braid formed to said shape by the force exerted upon each said braid by the elastic element surrounding it.

5. The electrical connector of claim 1 in which the structure for allowing said lateral play comprises a hole in said end plate having a larger diameter than the diameter of said hollow element and a ring surrnounting said hollow element, said ring attached to said end plate to form a cavity therein for allowing lateral play of said hollow element in said end plate.

6. The electrical connector of claim 1 in which said end plate has at least one rib extending from the surface of said end plate and lying between said plural hollow elements to stillen said end plate.

7. The electrical connector of claim l in which said end plate has at least one rib extending from the surface of said end plate on the side toward said body to stiften said end plate.

References Cited in the ille of this patent UNITED STATES PATENTS 2,189,987 Kellems Feb. 13, 1940 2,266,214 Kellems Dec. 16, 1941 2,310,212 Buchanan Feb. 9, 1943 2,434,358 Frank Jan. 13, 1948 2,690,541 Elliott Sept. 28, 1954 2,755,449 Anderson July 17, 1956 2,814,024 Norozny Nov. 19, 1957 2,845,604 Jackson ct al July 29, 1958 2,896,186 Hardmark July 2l, 1959 FOREIGN PATENTS 597,134 Germany May 17, 1934 694,985 Great Britain luly 29, 1953

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