US3902779A

US3902779A - Electrical cable connector

Info

Publication number: US3902779A
Application number: US458753A
Authority: US
Inventors: John C Herbert
Original assignee: Herbert Products Inc
Current assignee: Herbert Products Inc
Priority date: 1974-04-08
Filing date: 1974-04-08
Publication date: 1975-09-02
Anticipated expiration: 1992-09-02

Abstract

An improved electrical cable connector combining the benefits of a positive securement of an electric cable wire with a connector element that is detachably engageable in snug-fitting electrical transmitting connection with a takeoff spring-type connector element. The cable connector includes the application of an operable securement and coupling to place such connector elements in the electrical engagement and to so retain the same against accidental displacement until the operable securement is released to thereby permit the connector elements to be detached.

Description

United States Patent Herbert Sept. 2, 1975 [54] ELECTRICAL CABLE CONNECTOR FOREIGN PATENTS OR APPLICATIONS Inventor: John Herbert, Freepofl, 286,392 3/1928 United Kingdom 339/256 s [73] Assignee: Herbert Products, Inc. westbury, 607,247 3/1926 France 339/256 S N.Y. 1 Primary Examiner-Roy Lake [22] Fledi 1974 Assistant Examiner--Mark S. Bicks [21] APP] 458,753 Attorney, Agent, or FirmBauer & Amer 52 U.S. c1 339/89 R; 339/256 5; 339/272 R [57] ABSTRACT [5 1] Int. Cl. HOIR 13/54 An improved electrical cable connector combining the [58] Field of Search 339/89 R, 89 C, 256 R, benefits of a positive securement of an electric cable 339/256 C, 256 S, 272 R, 272 A, 272 UC wire with a connector element that is detachably engageable in snug-fitting electrical transmitting connec- [56] References Cited tion with a takeoff spring-type connector element. The

UNITED STATES PATENTS v cable connector includes the application of an opera- 938,188 10/1909 Wienhaver 339/89 c ble securiment and to Such connect? 2 007 443 7/1935 Feuchter u 339/256 8 elements in the electrical engagement and to so retain 2:329:998 9 H943 Meyer 339/272 R the same against accidental displacement until the op- 2 353 99 7/1944 st ff l 339 5 erable securement is released to thereby permit the 2,636,956 4/1953 Conrad 339/272 A connector elements to be detached. 2,906,986 9/1959 Schaefer 339/89 R 3,613,048 10/1971 Brundza 339/89 R 1 Clam" 2 Dmwmgngures u-u-uoa-u JIIIJIIJJJJ. 2

PATENTED EP 21915 ELECTRICAL CABLE CONNECTOR BACKGROUND OF THE INVENTION The invention relates to an improved electrical cable connector, and more particularly to one that is uniquely positive in its operation.

in the past, attempts have been made to provide electrical connectors that are separable or detachable and in which the reliability of the interconnectionbetween such electrical connectors was absolute or foolproof. In an attempt to achieve such an electrical connection, resort has been made to the pressure type engagement between a male plug and a spring functioning as a Chinese finger.

Although the benefits of the spring-type pressure connectors are well recognized, failuresin such connectors have frequently occured in the joining of the cable wire with the male connector element. To overcome this problem, the joining together of the connector with the male plug has been accomplished by securing the same together by inserting the cable wire into an opening defined in the plug and securing the same by a set screw.

Unfortunately, however, the strengthening of each part of the electrical connector often results in producing another part of weakened or lesser strength or resistance and/or electrical performance. Thus, it has been found that the reliability of the interconnection of the electrical connector elements is still not completely accomplished without providing the user of the connector with some means of positively knowing that the electrical connection has been made and that the same will be retained against accidental displacement.

In this regard, it is an object of the present invention to provide an electrical connector in which the interengagement of the connector elements is effected by the application of a positive pressure to force the same into the proper electrical connection and to be there retained until the pressure is deliberately released and fully removed. Thereafter, the electrical connection and interengagement may be separated and the connector elements detached from each other.

It is an object of the-present invention to provide an electrical cable connector incorporating, in combination, all the beneficial attributes of the coiled spring pressure contacts for simple and positive interengagement and separation and detachment of the connector elements and the positive joining together of the cable wire and male plug as well as the force applying operation of a securement means and coupler to effect the positive interconnection and engagement of the connector elements to prevent their undesired disconnection and to provide an indication of when the positive connection is made.

Another object and feature of the invention resides in the combined arrangement of structural details which enables the utilization of the best structural details of the prior art to provide an electrical cable connector that is simple in construction, foolproof in operation, and longer lasting than any of the prior art structures incorporating lesser features.

The following prior art is noted: US. Pat. Nos. Feuchter, 2,007,443; Schneider, 3,058,083; Mineck, 3,354,420; Florer, 3,465,281; Schaefer, 2,906,986.

The above description, as well as further objects, fea tures and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative, embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an expanded perspective view of an electrical cable connector constructed according to the teaching of the invention; and

FIG. 2 is a longitudinal cross-section of the assembled details of FIG. 1.

Referring now to the drawings, the electrical cable connector of the present invention is generally identified by the numeral 10. For ease of understanding, the connector 10 is adapted to complete an electrical circuit between an insulated cable 12 having an end thereof stripped of insulation to expose a bundle of the cable wires 14. The circuit is to be completed between the cable 12 and a connecting element 16 in the form of an electrical screw that is adapted to be threadedly mounted within an essentially closed end body 18. The threadable adjustment between the screw 16 and the body 18 enables the screw to be adjusted with respect to the adjacent surface 20 so as to permit the insertion of a further electrical connecting take-off element (not shown) between the screw head 16 and the surface 20.

The body 18 is illustrated elongated in length to define an interior to form an essentially closed elongated housing for the parts that are intended to be included therewithin. Recognizably, the body 18 may be of an insulating material and may be provided with a series of stepped

annular surfaces

22 and 24 to enable the same to be conveniently mounted within a corresponding sized opening that may be provided in the wall of any desired instrument so as to enable the secure mounting of the connector 10 to such wall as is illustrated in broken lines and identified by the numeral 26.

Connected to the electrical take-off screw element 16 is a female connector element in the form of a spring 28. The inside diameter of the spring 28 may be smaller than the thread diameter of the screw 16 such that when the same are threaded together in the manner as is illustrated in FIG. 2, the engagement between the connector element 28 and the screw 16 will be such as to prevent the displacement of the spring from the threads of the screw. Although in practice it has been found that this displacement will not occur when the frictional engagement between the spring and the screw is sufficiently great, it has also been found that to positively prevent any accidental disengagement of the two, the spring may be soldered or otherwise secured to the threads of the screw leaving a sufficient number of threads between the spring and the wall 20 of the body 18 to enable the screw to be unthreaded away from the wall 20 to enable the insertion of an electrical take-off terminal therebetween.

A further electrical connector element 30 is provided with an extension thereof in the form of a male plug 32 that is elongated in length and provided with an annular undercut 34 intermediate the ends thereof. The extreme end of the male plug is rounded so as to enhance its introduction and entrance into the interior of the coil spring 28. Those skilled in the art will readily recognize that the normal unstressed inside diameter of the coil spring 28 will be slightly smaller than that of the diameter of the male plug extension 32. Hence, when the male plug extension 32 is inserted into the coils of the spring 28, the same will have a tendency to tightly grip and relax within the annular undercut 34 to thereby more tightly engage the male plug and prevent its dislodgment therefrom.

The opposite end of the electrical connector element is provided with a blind hole 36 as seen in FIG. 2. The hole may be of such size as to easily, but closely, receive the exposed bundle of electrical cable wires 14. Although the wires 14 may thereafter be securely retained within the hole 36 by brazing and soldering and the like, it has been found in practice that the application of a set screw 38 functions as a locking element to prevent the dislodgment of the wires 14 from the male plug element 30. The connection between the male plug element 30 and the wires 14 and the locking function of the set screw 38 is further improved by a hole 40 that is positioned diametrically opposite the set screw 38 such that when the set screw is threaded down against the bundle of wires 14, they are caused to be displaced into the confines of the diametrically opposed hole 40 and, thus, positively locked in position within the male plug 30.

From FIG. 2, it will be seen that the outer size of the plug 30 is slightly smaller than the confining interior opening of the housing of the body 18 such that the movement of the plug within the enclosure or housing of the body 18 is guided by the walls thereof for positive engagement between the plug element 32 and the spring 28.

'An operable securing means or take-up element in the form of a nut 42 is freely movable along the length of the cable 12 by being provided with an internal through opening 44 that is slightly larger than the diameter of the cable along which the same will move. The securing element or nut 42 is provided with an enlarged shoulder 45 that presents a stop or limiting surface 46 that is adapted to engage with a similar stop or limiting surface 48 that is defined on the facing open axial end of the body 18.

The inside surface means the housing defined by the body 18 is provided with an elongated thread 50 that is adapted to cooperate with a complementary thread 52 provided and defined along an axial portion of the length of the nut 42. The distance between the end of the threaded portion of the nut 42 and the electrical connector plug element 30 may be taken up by a spacer coupling sleeve 54 having an internal through axial opening 56. Although in the drawing the take-up element or sleeve 54 is illustrated as separate from the coupling nut 42, those skilled in the art will readily recognize that the same may be formed integral. However, in manufacture, it has been found convenient to make the sleeve separate from the coupling nut to enable the selection of various lengths of such sleeves to adjust for the differences between the engaged position of the electrical connector element 30 as shown in FIG. 2 and the space defined between it and the limit surface 48 on the body 18.

In operation, the cable 12 is connected at its end 14 to the plug 30 by the set screw 38 after the securing take-up element 42 is slipped over the cable and also after the take-up coupling sleeve 54 is applied to the same in the manner as shown in FIG. 2. The body 18 may be connected to any convenient wall 26 of any instrument at the correspondingly sized

surface

22 or 24.

To complete a circuit between the cable 12 and the electrical connector element 16, it is merely necessary to unthread the element 16 away from the shoulder 20 and secure between them an appropriate electrical connector (not shown). The connector element 16 is then screwed back down tightly to secure whatever electrical take-off element is held between its head and the surface 20. This positive securement may be enhanced by brazing or soldering.

The male plug 32 is then guided into the essentially closed housing of the body 18 until its forward end enters the turns of the connector spring element 28, as far as it will travel. Because the normal internal dismeter of the spring element 28 is less than that of the diameter of the plug 32, certain of the turns thereof will spring into snug electrical engagement with the undercut surface 34 while the remaining turns will engage in the nature of a Chinese finger with the remaining surface of the plug.

Ordinarily, such engagement would be sufficient to make electrical contact between the cable 12 and the element 16 and whatever take-off electrical connection is made therewith. However, to provide for a more positive and complete electrical connection, the sleeve 54 is then moved into engagement with the facing large surface of the plug 30 by sliding the securing element 42 along the length of the cable until the threads 52 thereof engage with the threads 50 of the housing. Upon one direction of operation threading tightly the element 42 into the housing, the sleeve 54 is caused to apply a force to the plug 30 which causes its end 32 to engage more deeply within the spring 28. The connection between the plug 30 and its end 32 with the spring 28 is known to be complete when the limiting surface 46 of the securing element 42 engages snugly in tightfitting engagement against the abutting surface 48 of the body 18. At such time, the user will recognize that the male plug and the spring are in full electrical engagement.

It should be apparent to those who are skilled in the art that the arrangement of structural details now prevents any accidental disengagement between the pin 32 and the spring 28. It is impossible to separate the two until such time as the securing means 42 is operated in the reverse to unthread from the body 18. Obviously, by the proper selection of the length of the sleeve 54, it is possible to control the amount of force to be applied to the plug 30 and pin 32 to assure its positive and complete engagement with the spring 28. Furthermore, by providing for the cooperative limiting engagement between the

surfaces

46 and 48, it is now possible to provide the user of the present electrical cable connector with a visual recognition of exactly when the electrical connection between the cable 12 and the take-off element 16 is completed by way of the plug 30 and the spring 28.

Until such time as the securement 42 is unthreaded from its engagement with the body 18, it is impossible for the male plug to disengage from electrical connection with the cooperating spring 28. Because the overall construction of the connector is so positively complete when the securing element is driven home with its surface 46 engaged against the body surface 48, the parts contained within the connector body are inaccessible from any external damaging forces and, thus, the resulting cable connector is virtually free of damage and, therefore, becomes substantially foolproof in its operation.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment thereof,

it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

I claim: I. An electrical cable connector comprising a body, first and second detachably engageable electrical connector elements, the first of said elements being a coiled spring pressure contact member mounted on said body, the second of said elements being movable relative to said first element for detachable electrical engagement therewith, screw means on said second element threadedly engaging and securing a cable to said second element, operable securing means cooperating with said body to secure said first and second elements in engagement with each other, coupling means between said securing means and said second element to move the latter into nondetachable electrical engagement with said first element upon one operation of said securing means and to enable attachment of said first and second electrical elements upon another operation of said securing means, said body defining an essentially closed end sleevelike housing with said first connector element being 6 mounted in said body at said essentially closed end and having an opening defined therein,

an electrical take-off member on the exterior of said body extending through said defined opening and electrically connected with said coiled spring,

said operable securing means and said body each having cooperable thread means for relative threading and unthreading movement,

said second element being a male plug of a crosssectional size greater than the interior opening of the coiled spring to cause the same to expand in engagement thereabout to assure snug electrical engagement between the surface of said plug and the coils of said spring,

a narrowed portion on said plug into which the coils of said spring relax,

said plug having an axial opening in which the electrical wire of a cable may be received,

said screw means being a set screw for engagement with the cable wire to retain said plug and cable joined together,

said coupling means being a sleeve movable along the cable,

cooperable engaging means on said male plug and coupling means to force said male plug into electrical engagement with said coiled spring upon the one operation of said securing means,

and means on said male plug to axially compress the coils of said coiled spring about said male plug.

Claims

1. An electrical cable connector comprising a body, first and second detachably engageable electrical connector elements, the first of said elements being a coiled spring pressure contact member mounted on said body, the second of said elements being movable relative to said first element for detachable electrical engagement therewith, screw means on said second element threadedly engaging and securing a cable to said second element, operable securing means cooperating with said body to secure said first and second elements in engagement with each other, couplinG means between said securing means and said second element to move the latter into non-detachable electrical engagement with said first element upon one operation of said securing means and to enable attachment of said first and second electrical elements upon another operation of said securing means, said body defining an essentially closed end sleevelike housing with said first connector element being mounted in said body at said essentially closed end and having an opening defined therein, an electrical take-off member on the exterior of said body extending through said defined opening and electrically connected with said coiled spring, said operable securing means and said body each having cooperable thread means for relative threading and unthreading movement, said second element being a male plug of a cross-sectional size greater than the interior opening of the coiled spring to cause the same to expand in engagement thereabout to assure snug electrical engagement between the surface of said plug and the coils of said spring, a narrowed portion on said plug into which the coils of said spring relax, said plug having an axial opening in which the electrical wire of a cable may be received, said screw means being a set screw for engagement with the cable wire to retain said plug and cable joined together, said coupling means being a sleeve movable along the cable, cooperable engaging means on said male plug and coupling means to force said male plug into electrical engagement with said coiled spring upon the one operation of said securing means, and means on said male plug to axially compress the coils of said coiled spring about said male plug.