US2487521A

US2487521A - Snap type wire terminal

Info

Publication number: US2487521A
Application number: US36658A
Authority: US
Inventors: Swithin W Buckley
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-07-02
Filing date: 1948-07-02
Publication date: 1949-11-08
Anticipated expiration: 1966-11-08

Description

Nov. 8,1949 I S.W.BU CKLEY 2,487,521

SNAP TYPE WIRE TERMINAL Filed July 2, 1948 Smaentcv: SMITH/IV ll. 506K157 MJM Glforneg:

Patented Nov. 8, 1949 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to connectors and particularly to improvements in quick coupling solderless connectors for electrical circuits.

One of the major features of this invention resides in an electrical connector having separable parts which can be snapped together and which when so assembled provide an electrical connection which is completely covered by insulation. One modification provides a special post on which a plurality of the snap type terminals may be engaged, the outside snap terminal being provided with an insulating shell or casing which covers all of the terminal parts.

In general, the invention provides a snap type solderless connector comprising a stud member and an eyelet member, to which separate electrical conductors are attached. The stud and eyelet members are provided with a plurality of projecting prongs or fingers under which the ends of the electrical conductors are secured in a clinched relation to provide firm electrical contact which requires no soldering. The conductors are attached to the stud and eyelet members in such a manner that the surfaces of the mechanically interlocked stud and eyelet are in a position substantially normal to the direction of pull on the conductors so that the parts of the connector cannot be readily separated by a straight pull on the conductors.

It is a general object of the invention to provide improved snap type quick coupling terminals to constitute a connector unit by which a plurality of conductors may be quickly connected and disconnected; in which the parts of the connector may be quickly engaged and disengaged; in which the parts of the connector will have positive electrical contact; will not disengage readily by a straight pull on the conductors to which the connector elements are attached; which will have a positive means for connecting the electrical conductors to the elements of the connector and will not require soldering; and which, while having all of the above advantages, will also be inexpensive to manufacture.

Other and further objects will become readily apparent from the following description when considered in connection with the accompanying drawings illustrating an embodiment of the invention, and in which:

Figure 1 is a side elevation in partial section of two elements of the connector in assembled relation, each part having an electrical conductor connected thereto;

Figure 2 is a top plan view of the eyelet elevertical sectional view and a bottom plan view" 2 ment showing the manner in which the end of the conductor is attached to the element; Figure 2a and Figure 2b, respectively, are a of Figure 2;

Figure 3 is a top plan view of the stud element of the connector;

Figure 3a and Figure 3b, respectively, are a vertical sectional view and a bottom plan view of Figure 3;

Figure 4 is a vertical section of the insulating cap for the eyelet member;

Figure 5 is a bottom plan view of Figure 4;

Figure 6 is a partial vertical section of a modified form of the invention in which the stud element is in the form of a terminal tower adapted to receive a plurality of the eyelet elements in stacked relation; and

Figure 7 is a partial vertical section of another modified form of the invention in which the stud element is attached to the terminal ear of an accessory part.

The embodiment of the invention chosen for the purposes of illustration is designed to be attached to the ends of solid or stranded insulated electrical conductors of sizes approximately from No. 8 to No. 18 which are commonly used in the electrical systems of automobiles, airplanes and similar other equipment.

. In general, the connector comprises conductor terminal pieces in the form of an eyelet element H and a stud element terminal [2, the eyelet having a plurality of resilient fingers provided with inturned hook-like ends adapted to engage an annular recess in the stud element to hold elements in assembled relation. In the most common form of the invention adapted to connect together the two ends of conductors for a straight through connection, the respective elements are provided with insulating caps Ila and 12a. As will be explained later, the cap Ila will not be associated with the eyelet element when the latter is adapted to engage a terminal tower which receives a number of the eyelet terminals. In such an event one of the eyelet elements will be provided with a modified form of the cap member similar to that shown in Figure 6 which is adapted to cover all of the terminals. An eyelet terminal and a stud terminal forming a straight through connection between two conductors l3 and I4 are shown in assembled relation in Figure 1.

Both the eyelet terminal element and the stud terminal element are of such a design that they may be made by automatic machinery by performing certain operations on blanks stamped from sheet material. It will be readily assumed that the appropriate sheet material having good electrical conducting properties such as copper, aluminum or bronze, would be chromium-plated or cadmium-plated where necessary to prevent rusting or corrosion. As will be readily apparent from the drawings, the eyelet terminal is provided with inturned hook-like edges which are adapted to engage an annular recess in the stud element to hold the connector elements in assembled relation.

In the preferred form of the invention, the eyelet and the stud elements will be punched from disc blanks. The eyelet is formed from a plane blank having a central hole with serrated edges, the outer edge of the blank also being provided with serrations forming fingers. The eyelet element will be formed in the shape substantially as shown in Eigures 2 to 21), inclusive. It W 11 be noted that the eyelet is provided with a cylindrical portion It, the lower portion of which is divided into sections separated by slots ii to form fingers 5 6a 'The bottom ends of these fingers are turned inwardly as at 58 to provide resilient hook-like ends to engage an annular recess 19 of the stud element when in assembled relation. It will be understood that preferably the blank stock from which the eyelet element is made will have suffi cient resiliency so that the hook-like ends 53 will engage the recess of the stud with a snap action. Although the sequence of operations in making the terminals does not constitute a part of the invention, it will be readily appreciated that variation will be possible.

As an erample, the initial fiat disc blanks from which the eyelets are made may be serrated bot in its inner periphery and outer periphery so that subsequent stamping operations will form the cylindrical part It consistng of the separate fingers H30, and the outer periphery will have an annular series of reentrant fingers 2| and 22 which would be bent into the shape shown in the drawings by subsequent operations and which are integral with the flange or breast portion 25. The fingers 2i are bent upwardly and inwardly from the outside periphery toward the central part of thev eyelet and are adapted to engage recessees 25 in an insulating cap ila. As will be explained later, where the eyelet is not to be provided with the insulating cap Ha these fingers 2i would be bent further inward in a manner similar to fingers 22. The fingers 22 are folded inwardly as shown to form a raceway surrounding the cylindrical part it; into which the bare conductor 13 may be pushed so that with a subsequent operation the fingers 22 could be clinched down over the conductor thus eliminating the necessity of soldering the eyelet terminal to the conductor. One of the fingers 22 would be draw-punched to form a tubular extension 22a through which the conductor l 3 is inserted into the raceway. It will be understood that in the event the eyelet terminal is not to be provided with the insulating cap l la the alternate fingers 2! would likewise be bent down in clinched relation around the conductor. Where the eyelet terminal is to be provided with the insulating cap Ha, the latter would be assembled over the eyelet element in such a manner that the recess H b of the insulating cap would straddle the conductor and the fingers 21 would engage the recesses 23 and would be held therein by frictional engagement when the cover Ila and the eyelet terminal were pressed together sufficiently.

For the purpose of faciltating the insertion of the conductor l3 in the raceway formed by the curved fingers, a triangular tongue 21 would be punched during the appropriate operations so that when the conductor [3 is pushed through the tubular extension 22a in one of the fingers 22, the strands of the multiple strand conductor will be divided so that part of them will proceed around one side of the raceway while the others will proceed around the other side. If the conductor. is solid the tongue 27 will aid in guiding it around the raceway. Also suitable contact fingers 28 in the form of integral tongues will be punched from the main body of the eyelet, these contact fingers being adapted to engage the flange or breast'portion 29 surrounding the stud element. The purpose of these contact fingers 23 is to increase the contact surface and pressure between the two elements and to maintain the proper contact pressure between the elements as it will be understood that the contact fingers 28 will be held in a compressed position when the pronglike hooks I8 engage the annular recess it of the stud element.

It will be readily understood that the relative position of the hook ends l8 with respect to plane and relative position of the annular recess it will be such that when the elements are in as sembled relation the hook ends [8 can move slightly beyond the recess Is and then spring back under the force of the fingers 28.

It is important to note that in constructing the component eyelet and stud elements and the present connector, the hook ends H! on the resilient fingers la should preferably lie in a plane X-X which is above the plane of the contact fingers 25 and the annular recess IQ of the stud element should lie in our slightly above the plane Y-Y of the flange or breast portion 29 of the stud element so that when the eyelet element is assembled and the hook elements [8. engage the annular recess 19, the contact fingers 28 will rest firmly against the upper surface of the breast portion 29.

ue to the resiliency of the fingers 28, there will be firm contact between the latter and the breast portion 29 as well as between the hook ends [8 and the underside of the annular recess [9. The area of contact between the fingers 28 and the flange or breast portion 29 of the stud element as well as that between the hooks l8 and the underside ofthe recess 19 would be preferably such that it would be substantially equal to the normal elec trical capacity of the conductors l3 and It so that an efficient electrical connector is provided. It will be readily apparent that when the hook ends l3 are engaged in the annular recess l9 of the stud element, the two elements can be readily rotated relative to each other, whereby k nking of the conductors will be substantially eliminated. In other words, instead of a kink developing in the conductors to which the connector elements are attached, the elements can rotate relative to each other and eliminate the tortional stresses in the conductors. It will be readily apparent that at the same time the connector elements cannot be separated by a straight pull on the conductors and that in order to separate the conductors it Will be necessary to pry them apart laterally so that the hook ends it snap out of the annular recess IS in the stud element. The insulating covers I la and [2a provide a very eficient means for colorcoding the connectors which are to be connected together. Also, if desired, it will be readily apparent that a coding of the connectors can be accomplished by means of physical configuration so that an eyelet and stud element attached to electrical conductors which it is desired to connect could be unmistakably assembled in the dark. As one example of coding the connector elements, insulating covers of varying diameter could be utilized. 7

;It is believed that in view of the above description, further. description of the stud element is unnecessary since the stud element is merely the complementary part of the eyelet piece and a separate conductor is connected to the stud piece in the manner already described. Suffice it to say, the stud piece may be formed by a drawpunch operation from a disc blank, the stud portion itself extending above the breast portion29 or main body of the stud element. As in the eyelet element, the outer periphery of the blank would be serrated so that in the subsequent operations the reentrant fingers 3| and 32 would be formed, the fingers 3| being adapted to engage recesses in an insulating cover |2a similar to that shown in Figure 4 when it was desired to insulate the stud element. However, if it is desired to mount the stud element as shown in Figure '7, all of the fingers 3| and 32 would be crimped toward the underside of the breast portion 29 to engage the conductor l4. A suitable triangular tongue 33 would be struck inwardly and downwardly (as viewed in Figure 3a) from the breast portion 29 to facilitate the guiding of the bare conductor l4 in the raceway formed by the turned-over fingers 3|. When the stud element is to be provided with an insulating cover, the latter would be assembled over the fingers 3| in such a way that the fingers would engage recesses in the insulating cap similar to that shown in Figures 4 and 5 and the stud element would be permanently locked together by pressing the teeth into the recesses in the insulating cover.

When it is desired to connect a number of conductors to one terminal point, the stud element may take the form of a terminal tower 3B which may be hollow or a solid piece of metal provided with spaced annular recesses 31 corresponding to the number of eyelet terminals to be connected to the terminal tower. In this instance only one of the eyelet elements would be provided with an insulating cap 38 which would have a flange 39 deep enough to cover all exposed parts of the assembled eyelets and the terminal tower so that the assembl would be completely insulated. It

will be readily apparent that 'the terminal tower may be riveted or screwed in the terminal ear (not shown) of any piece of electrical apparatus.

If desired a hollow terminal tower adapted to receive a plurality of eyelet terminals or a stud element to receive only a single eyelet element may be attached to an insulating cover 4| in the manner shown in Figure 7. In this modified form the stud element 42 could be made similar to the-stud element previously described, with all of the outer fingers bent under, the stud element 42 being electrically connected to an electrical conductor 45 through a suitable hollow split rivet 44, or similar element. In addition to the usual annular recess 42a, the stud element 42 is provided with an additional annular recess 43 which is adapted to receive a complementary annular indentation in the split rivet 44. It will be understood that the recess 42a will be so located on the stud 42 that when an eyelet element is assembled thereon the resilient contact fingers 28 will firmly engage the flange or breast portion 29 and the hook ends l8 will firmly engage the underside of recess 42a, as in the embodiment previously described.

It will be readily understood that the stud el ment 42 may be provided with a plurality of spaced annular recesses to receive a plurality of eyelet elements in a manner similar to the embodiment of Figure 6. In either event the spacing of the annular recesses would be such that a firm electrical contact would be provided between the contact fingers 28 on the eyelet and the flange or breast portion of the stud element or the flange or breast portion of the next adjacent eyelet.

From the foregoing description it will be readily' apparent that the present invention provides a snap type quick-coupling connector comprising complemental parts which may be connected and disconnected by snap action. In view of the fact that the electrical conductors are connected to the terminals at substantial right angles to the mechanical connection between the terminals, it is practically impossible to disengage the terminals by a straight pull on theconductors. It will be readily apparent that this has a very decided advantage. On the other hand, the complemental terminals can be readily separated by placing a suitable instrument such as a screw driver in the recess 50 and prying apart the respective elements of the terminal. It will also be readily apparent that the insulating covers of the complemental terminals provide complete insulation for the terminal joint. Because of the similarity between certain parts of the complemental eyelet and stud members, it is possible to perform a maximum number of manufacturing operations for both types of terminals on a single machine or type of machine which results in a saving of manufacturing costs. Also, simplicity of manufacture results from the fact that both of the parts of the terminal can be made from the same blank.

Although the invention has been described in considerable detail, it will be apparent to those skilled in the art that many variations are possible without departing from the inventive concept,

I claim:

1. An electrical connector for connecting electrical conductors comprising an eyelet element and a stud element. said eyelet element comprising a centrally located cylindrical portion slotted to form a plurality of resilient fingers having their ends inturned to form hook-like elements, said eyelet also having a radially outwardly extending annular flange or breast portion provided with resilient contact fingers displacedoutwardly from the plane of said breast portion, said stud element having a central stud portion and an annular flange or breast portion extending radially outwardly therefrom, said stud portion having an annular recess adapted to be engaged by said hook-like elements when said eyelet element and said stud element are engaged in assembled relation, said hook-like elements being so spaced with respect to said resilient contact fingers and said annular recess being so related to said breast portion of said stud element in such relation when said hooklike elements engage said annular recess that said resilient contact elements will engage the breast portion of said stud element in compressed relation.

2. An electrical connector for connecting electrical conductors comprising an eyelet element and a stud element, each of said elements having centrally located means cooperating to hold said elements together in assembled relation to prevent lateral separation while permitting relative rotation, each of said elements having breast portions extending radially outwardly from said centrally located holding means, said eyelet element having a plurality of resilient tongues struck out from the plane thereof, said resilient tongues being so related to said breast portion as to firmly engage the annular breast portion of said stud element in firm electrical contact when said centrally located holding means are engaged by said elements together in assembled relation, said breast portions being of arcuate across section and being provided with an annular series of fingers under which an electrical conductor may be held in tight frictional engagement when said fingers are bent down in clinched relation with respect to said breast portions.

3. An electrical connector for connecting electrical conductors comprising an eyelet element and a stud element, each of said elements having centrally located means cooperating to hold said elements together in assembled relation, each of said elements having an annular breast portion extending radially outwardly from said centrally located means, resilient contact means carried by the breast portion of said eyelet element and being so disposed relative to said holding means as to be held under compression against the breast portion of said eyelet element when said means are engaged to hold said elements together in assembled relation, said breast portions being of arcuate cross section and being provided with an annular series of fingers under which an electrical conductor may be held in tight frictional engagement when said fingers are bent down in clinched relation with respect to said breast portions.

4. An electrical connector for connecting electrical conductors as set forth in claim 3 in which said connector elements are provided respectively with cup-shaped insulatingcovers so related to said elements that when said elements are in assembled relation completely enclose the re spective parts of said connector.

5. An electrical connector for connecting electrical conductors, comprising an eyelet element and a stud element, each of said elements having an annular breast portion of arcuate cross section, one side of said breast portions being provided with integral fingers arranged in an annular series to form an annular race-way into which an electrical conductor be dispersed so that conductors may be attached to said elements in intimate electrical contact by clinching said fingers against the under side of said breast portions, one of said elements having centrally located resilient means and the other of said elements having complementary means adapted to be engaged by said resilient means to retain said elements in assembled relation, resilient contact means carried by one of said elements and adapted to engage the breast portion of the other element under compression when said elements are in assembled relation.

6. An electrical connector comprising an eyelet element having a central cylindrical portion split longitudinally from one end to provide individual resilient fingers, said resilient fingers having in-turned hook-like beads, an annular skirt flaring out from the other end of said cylindrical portion to form an annular breast portion having an annular series of fingers which curve over the back side of said breast portion in re-entry relation to form an annular slot or race-way into which an electrical conductor may be disposed and held by said fingers when the latter are in clinchedrelation; and a stud element comprising a central cylindrical portion having an annular recess, an outer radial annular portion provided with an annular series of fingers adapted to hold an electrical conductor in clinched relation, said eyelet element and said stud element adapted to be engaged in assembled relation with said hook-like element engaging said annular recess in said stud element.

7. An electrical connector comprising an eyelet element and a stud element, each of said elements having centrally located means cooperating to hold said elements together in assembled relation, an annular breast portion extending radially outwardly from said centrally located means, resilient contact means carried by said eyelent element and being so related to said holding means as to engage the breast portion of said stud element when said holding means are engaged to hold said elements together in assembled relation, said breast portions being of arcuate cross section and being provided with an annular series of fingers, alternate ones under which an electrical conductor may be held in *5 tight frictional engagement when said fingers are bent down in clinched relation with respect to said breast portions, cup-shaped insulating coversfor each of said elements having recesses therein and the other of said fingers engaging said recesses to hold said cup-shaped insulating covers in assembled relation with the respective elements.

SWITHIN W. BUCKLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS