US3787795A

US3787795A - Solderless terminal assembly

Info

Publication number: US3787795A
Application number: US00241993A
Authority: US
Inventors: J Thompson; G Gillemot
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-04-07
Filing date: 1972-04-07
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22

Abstract

A solderless terminal strip of U-shaped, tempered, resilient metal having an opening in its bight for receiving the end of a conductor and clamping the same between the legs thereof as the latter are clamped together. Sharp edged pimple-like protruberances bite into the conductor to assure electrical contact and a strong mechanical anchorage. The clip legs are formed with channels, lengthwise thereof, preferably non-linear and of a size firmly seating the similarly shaped end of a conductor. Smaller sized conductors are accommodated by selecting a split sleeve adapter of suitable size to telescope over the conductor and be clamped between the legs of the clip.

Description

United States Patent [191 Thompson et al.

[ SOLDERLESS TERMINAL ASSEMBLY {76] Inventors: John T. Thompson, 244 Loring St.,

abandoned.

[52] US. Cl. 339/14 R, 339/95 R, 339/263 R, 339/266 R [51] Int. Cl H01r 7/08 [58] Field of Search.... 339/95 R, 95 A, 95 B, 95 D, 339/96, 97 R, 97 L, 97 P, 97 S, 97 T, 14 R,

14 L, 246, 250, 263 R, 263 B, 263 E, 263 L,

263 S, 264 R, 264 L, 266 R, 266 F, 266 G, 266 L, 270 R, 270 F, 273 R, 273 A, 273 F, 273 S, 259 R, 259 F, 105, 107; 24/125 R,

[56] References Cited UNITED STATES PATENTS 2,083,606 6/1937 Johansson 339/266 R Jan. 22, 1974 3,477,060 11/1969 Lanlol' 339/266 R 2,228,344 l/l94l Demeo 173/259 2,715,714 8/1955 Pavlinetz 339/213 R 5 7] ABSTRACT A solderless terminal strip of Ushaped, tempered, resilient metal having an opening in its bight for receiving the end of a conductor and clamping the same between the legs thereof as the latter are clamped together. Sharp edged pimple-like protruberances bite into the conductor to assure electrical contact and a strong mechanical anchorage. The clip legs are formed with channels, lengthwise thereof, preferably non-linear and of a size firmly seating the similarly shaped end of a conductor. Smaller sized conductors are accommodated by selecting a split sleeve adapter of suitable size to telescope over the conductor and be clamped between the legs of the clip.

27 Claims, 9 Drawing Figures PAIENIEHJANZZIW 3.787. 795

/5 INVENTORS. 36 JOHN 7T THOMPSON eoeee w G/AQEMUT FIG: a

SOLDERLESS TERMINAL ASSEMBLY This application is a continuation of our copending application for United States Letters Pat. Ser. No. 80,993 filed Oct. 15, 1970 entitled Solderless Terminal Assembly, now abandoned. 1

This invention relates to solderless terminal devices, and more particularly to an improved high strength solderless connector clip effective to provide a high strength mechanical and electrical connection between the end of the conductor and an anchorage therefor.

Many expedients have been resorted to heretofore by designers in attempts to provide a solderless connector and achorage for conductors. Certain of these have been quite satisfactory for the particular conditions sought to be satisfied. However, these prior designs are deficient in numerous respects, both structurally and functionally, to meet the requirements under more exacting and failproof operating conditions. For example, the provision of a high capacity failproof, high efficiency ground is an absolute must for a wide range of electrical equipment including power transmission systems, communication systems, electronic equipment, and computer equipment to list but a few. Usually such grounding systems employ a size 6 to size copper conductor having one end connected to the equipment and the other end connected to a grounding stake, an underground water pipe or the like. Such grounding connections must be capable of and equally effective to pass both low and high potential currents and must withstand severe and abusive shock and vibration conditions over a long period of time.

To meet these exacting and rigorous requirements there is provided by the present invention a solderless connector or terminal clip of simple, inexpensive, rugged construction capable of being opened and reclosed repeatedly without loss in efficiency. The clip in a typical configuration comprises a U'shape strip of strong metal having an opening in its bight portionopening into one end of a non-linear passage conforming to the size and shape of the grounding conductor. These conductor receiving channels are provided with dimplelike protruberances of tempered metal of very substantially greater hardness than the conductor and which readily deform and interlock with the conductor metal as the open end of the clip legs are forced together by the tightening of the assembly bolt. The non-linear shape of the receiving channel for the conductor requires that a corresponding portion of the conductor be similarly formed and cooperating with the protruberances in anchoring the conductor to the clip and partic-' ularly in preventing rotation of the conductor about its axis. The clip readily accommodates smaller diameter conductors by the use of an appropriately sized split sleeve adapter inserted over the conductor and clamped closed about the conductor as the clip legs are forced together.

Accordingly, it is a primary object of the present invention to provide a new and improved high efficiency, positive action, solderless connector for ground wires and the like.

Another object of the invention is the provision of a heavy duty, high efficiency, solderless connector for ground connectors usable repeatedly and providing a high strength mechanical and electrical connection therewith.

Another object of the invention is the provision of a solderless connector comprising a U-shaped tempered metal clip shaped to clamp a conductor end between the legs thereof and to upset portions of the conductor metal as the legs are clamped closed.

Another object of the invention is the provision of a solderless connector usable selectively with conductors of different size and including a range of adapters for use with conductors of smaller size than the conductor for which the connector is nominally designed.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

FIG. 1 is a longitudinal cross sectional view through one preferred embodiment of the invention solderless terminal clip shown assembled to a cable shielding sheath;

FIG. 2 is an exploded perspective view of the terminal clip and a conductor;

FIG. 3 is a cross sectional view on an enlarged scale taken along line 33 on FIG. 1;

FIG. 4 is a longitudinal sectional view of the clip assembled to the conductor prior to being closed;

FIG. 5 is a perspective view of an adapter useful in anchoring a smaller size conductor to the clip;

FIG. 6 is a longitudinal sectional view showing the FIG. 5 terminal clip and adapter fully assembled; and

FIGS. 7, 8 and 9 are cross sectional views on an enlarged scale taken along line 77, FIG. 6, and showing different size adapters assembled to different size conductors.

Referring initially more particularly to FIGS. 1-4, there is shown a preferred embodiment of the invention solderless terminal, designated generally 10. The basic connector clip comprises a U-shaped strip 11 of tempered, resilient, high conductivity metal comprising two similarly shaped

legs

12,13 interconnected by a U- shaped bight portion 14 formed with an opening 15 large enough to freely pass a conductor, such as a size 6 copper ground wire 16.

Initially, clip 11 is ductile and easily formed to shape including a pair of oppositely facing semi-round

nonlinear channels

17,18 having a combined depth somewhat less than the diameter of the wires or conductor 16 as clearly shown in FIG. 3. As shown in FIGS. l-4,

channels

17,18 are straight throughout the major length thereof but have their inner ends curving in the same direction, as is clearly indicated at 19 in FIG. 2. The end 20 of conductor 16 is preferably bent by the workman to conform with the shape of portions 19 of

channels

17,18. Accordingly, it will be readily apparent that, upon closure of the

legs

12 and 13, the conductor is snugy and rigidly clamped between the channels making it impossible for the conductor to be rotated about its own axis because of the interference provided by its bent end 20 acting in cooperation with the similarly bent ends of

channels

17,18.

The bottoms of at least one and preferably both of the

channels

17,18 are formed, as by a prick-punch, with conical depressions 22 to provide similarly shaped inwardly projecting pimple-like protruberances 23. After these have been formed clip 11 is heat treated in a manner well known to render the same highly resilient and much harder than conductor 16. I

Referring now more particularly to FIG. 1, there is shown a typical operating installation of the invention solderless terminal fully assembled to an electrical cable having a multiplicity of conductors 25. These are enclosed by an inner thin insulative sheath which is embraced by a foil-like conductive electrostatic shield 26 encased within a tough elastomeric cable sheath 27. A high capacity electrically conductive path between the shielding layer 26 and the clip 11 is provided by the shoe assembly now to be described and the details of which are more fully disclosed in our copending application for United States Letters Pat., Ser. No. 265,158, filed Oct. 4, 1968. This anchorage assembly comprises an inner metallic shoe 29 anchored to a threaded stud 30 assembled through aligned openings in

layers

26 and 27 and through an opening in an outer clamping shoe 32. Shoe 29 and stud 30 can be assembled through the described mounting openings while

layers

26 and 27 are pulled outwardly away from the cable conductors proper, an operation facilitated by slitting the ends of

sheaths

26,27 lengthwise of the cable as is indicated at 34 in FIG. 1. This slit permits spreading the slit sheaths and bending the cable conductors into slit 34 far enough to permit insertion of threaded stud 30.

Thereafter the sheath is folded back around the conductors and clamped in place thereagainst by servings of friction tape 35. The outer shoe 32 is then placed over the stud and clamped snugly by the inner clamping nut 36. Thereafter, the aligned openings in the outer ends of the legs l2, 13 of clip 11 are inserted over stud 30 and clamped snugly against the ground wire 16 by lock nut 38. This forces the clip legs together and causes protruberances 23 to bite deeply into the conductor as the bottoms of

channels

17,18 seat firmly against the juxtaposed surfaces of conductor 16.

The assembly is now complete except that in most cases it is preferable to align the length of terminal clip with the cable, water pipe or other object to which it is anchored and then to wrap several convolutions of friction tape about both the ground wire and the cable in an area spaced close to but to the left of the clip proper. This safeguards against the ground wire acting as a lever to rotate the assembly about the axis of threaded stud 30 and loosen the clamping nut.

Referring now to FIGS. 5-9, there is shown a preferred mode of using the invention terminal clip 11 with a ground conductor of smaller size than that for which the clip is normally designed. This is accomplished by using an appropriate one of different size adapter sleeves 40,41,42. Each of these sleeves is split longitudinally thereof, as is indicated at 44, and has the same exterior dimensions as the bottoms of

channels

17,18 but have internal dimensions corresponding to a particular different size ground wire. The opposite sides of each adapter are also preferably provided by shallow conical depressions 45 of shorter depth than protruberances 23, and spaced to register with these protruberances. lf adapters 40 are used with a clip having

non-linear channels

17,18 then the adapters are only as long as the straight portions of these channels.

The assembly of the adapters to the wire and to the terminal clip involves first telescoping an adapter of the proper size over the end of a straight conductor following which the protruding end of the conductor is bent to conform with the hooked end 19 of the channel. Thereafter the conductor and adapter are inserted through opening in the bight end of the clip, care being exercised to seat the protruberances 23 in conical depressions 45 thereby assuring that the slit 44 in the adapter sleeve will open laterally between the legs of the clip. It will be recognized that the adapter sleeves will then have maximum gripping action on the conductor as the clip legs are forced closed thereagainst. Tightening of nut 38 not only forces the parts into friction-tight gripping relation but causes protruberances 23 to penetrate further into the conical recesses 45 in the adapter sleeve.

Accordingly and in the manner described an exceptionally high strength mechanical and electrical anchorage is provided by the same clip assembly against a smaller size conductor 16'.

While the particular solderless terminal assembly herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiment of the invention, and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

We claim:

1. A solderless terminal clip for use in forming a high strength mechanical and electrical connection between a single cylindrical conductor and a clamping bolt, said terminal clip being stamped from strip metal and bent crosswise of its midlength into a flaring U-shape with straight legs, said terminal clip having an opening centrally of its bight portion axially aligned with the adjacent ends of substantially smooth non-threaded adjacent faces of opposed long channels of semi-circular cross-section stamped into and extending lengthwise of the clip legs and freely receptive of the conductor to be clamped as the conductor is inserted axially through said opening and between the flaring legs of said clip, at least one pimple-like protuberance projecting inwardly from the bottom of at least one of said channels and positioned to bite into a conductor extending through said opening into juxtaposition with said protuberance lengthwise of and between the legs of said strip as said flaring legs are pressed into parallelism against the opposite sides of a conductor, aligned openings through said legs near the free ends thereof for the reception of clamping means for closing said legs against the opposite sides of a conductor, said U-shaped strip and said pimple-like protuberance being tempered to render said clip highly resilient and all portions thereof substantially harder than the hardness of the conductor to be clamped, and the free ends of said legs having a pair of aligned openings for fastener means to force said legs toward one another whereby the forced closing of said legs against a conductor forces said pimplelike protuberances to penetrate into the conductor and whereby said resilient legs relax the grip on a conductor as clamping pressure between the free ends of said legs is relaxed.

2. A solderless terminal clip as defined in claim 1 characterized in the presence of a pimple-like protruberance on the inner face of each leg of said U-shaped strip.

3. A solderless terminal clip as defined in claim 1 characterized in that said channels are shaped to conform with the juxtaposed surface of a conductor of the size for which said terminal strip is designed.

4. A solderless terminal clip as defined in claim 1 characterized in that the axes of said channels are similar, non-linear and effective when clamped closed against the similarly shaped non-linear end of a conductor to preventaxial rotation of the conductor relative to said terminal strip.

5. A solderless terminal clip as defined in claim 1 characterized in that at least one of said channels is formed to seat and clamp the bent free end of a conductor and cooperable therewith to prevent rotation of a conductor about the axis thereof.

6. A solderless terminal clip as defined in claim 1 characterized in that each of said channels includes a plurality of said protruberances projecting toward one another from the bottoms of the respective channels.

7. A solderless terminal clip as defined in claim 1 characterized in that said strip is formed initially to shape from ductile stock and then tempered to render the same hard and resilient.

8. A solderless terminal clip as defined in claim 1 characterized in that the metal thereof is tempered to render the same hard and resilient, and said protruberance being sharp edged and sufficiently hard for repeated use without materially altering the sharp edge thereof.

9. A solderless terminal clip as defined in claim 1 characterized in the provision of adapter means for converting said clip to grip a conductor of smaller diameter than can be clamped between said chann'els comprising a split sleeve metal having an OD. corresponding generally with the shape of said channels and an ID. having a loose telescopic fit with the particular size of conductor to be used therewith.

10. A solderless terminal clip as defined in claim 9 characterized in that said split sleeve is formed with dimples positioned to internest with said pimple-like protruberances on said strip when properly assembled in said channels and between the legs of said strip.

11. A solderless terminal clip'as defined in claim 10 characterized in that said dimples are diametrically opposed to one another and spaced substantially equidistantly from the opposite sides of the split in said sleeve.

12. A solderless terminal clip as defined in claim 1 characterized in the provision of a tubular adapter sleeve slit along one side thereof and having a length not in excess of the length of said channel, said adapter sleeve being sized to snugly grip a smaller diameter conductor that can be effectively clamped between the legs of said clip, and the exterior of said sleeve being generally complemental to the shape and size of the channels in the legs of said clip.

13. A solderless terminal clip as defined in claim 12 characterized in that the interior side walls of said sleeve closely adjacent one side of said slit are formed with sharp pointed protruberances effective to penetrate a conductor assembled lengthwise therewithin as the clip legs are tightened toward one another.

14. A solderless terminal clip as defined in claim 1 characterized in the provision of a plurality of adapter sleeves selectively usable to clamp conductors of different respective sizes between the channels extending lengthwise of the legs of said clip, said adapter sleeves having O.D. complemental to the juxtaposed surfaces of said channels and different l.D.s corresponding to that of respective conductors all smaller than the diameter of said channels along said clip legs.

15. A solderless terminal clip as defined in claim 14 characterized in that the length of said plurality of adapter sleeves is less than the length of said channels along the legs of said clip.

16. A solderless terminal clip as defined in claim 14 characterized in that each of said plurality of adapter sleeves are slit lengthwise of only side thereof.

17. A solderless terminal clip as defined in claim 14 characterized in that said adapter sleeves have a plurality of sharp pointed protruberances projecting inwardly from the interior surface thereof and adapted to penetrate a conductor as the legs of said clip are tightened toward one another.

18. A solderless terminal clip of resilient tempered strip metal of divergent U-shape prior to clamping about the exposed end of a single solid conductor inserted between the legs of said clip through an opening in the bight portion thereof, said clip legs being straight and formed from uniform thickness strip stock and deformed lengthwise thereof to strengthen the same and to provide shallow juxtaposed planar channels having generally smooth semi-cylindrical surfaces and a combined depth less than the diameter of the conductor to be clamped therebetween, said channels being free of threads and having one end in communication with said opening in the bight portion of said clip and the other end terminating short of the free ends of said clip legs, the cross sectional shape and size of said smooth semicylindrical channels being effective to provide a powerful grip on the juxtaposed surface of a conductor positioned therebetween as the smooth non-threaded surfaces of the clip legs are pressed into parallelism with one another and against a conductor therebetween, and means extending between the free ends of said legs to force the same toward one another to clamp a conductor immovably in place therebetween.

19. A terminal clip as defined in claim 18 characterized in that said channels are curved lengthwise thereof and adapted to seat the similarly curved end of a conductor and cooperating therewith to hold the conductor against rotation when said clip legs are tightened against a conductor.

20. A terminal clip as defined in claim 18 characterized in that said channels are curved lengthwise thereof and in a plane parallel to the width of said clip legs.

21. A terminal clip as defined in claim 18 characterized in that at least one of said channels includes a plurality of sharp pointed protruberances projecting inwardly from the bottoms thereof.

22. A terminal clip as defined in claim 18 characterized in that the bight portion of said clip is highly resilient whereby said legs tend to resume the divergent position thereof automatically as said clamping means between the free ends thereof is loosened thereby releasing and freeing a conductor for withdrawal through the bight portion of said clip.

23. A solderless terminal clip formed from a length of strip stock bent into a flaring U shape, said clip having an opening centrally of its bight portion in communication with the adjacent ends of shallow generally smooth non-threaded long channels pressed into the respective clip legs with their non-threaded open sides facing toward one another, the depth of said channels being less than one half the diameter of conductive means clampable between said legs, a plurality of sharp edged protuberances projecting inwardly from the bottom of said channels, said clip and said protuberances being tempered to harden the same, said opening in the bight portion of said clip being adapted to receive a single solid conductor to be clamped between said legs as the free ends thereof are clamped toward one another from the opposite sides of a conductor positioned therebetween, said clip having been tempered to a hardness substantially greater than the hardness of a conductor to be clamped therein, and means at the free ends of said legs for clamping said channels into parallelism to clamp a conductor powerfully and immovably assembled therebetween.

24. A terminal clip as defined in claim 23 characterized in that said shallow channels terminate short of the free ends of said legs and short of said clamping means.

25. A terminal clip as defined in claim 23 characterized in that the free ends of said legs have aligned openings therethrough to receive a threaded clamping memher.

clamped against a conductor.

Claims

1. A solderless terminal clip for use in forming a high strength mechanical and electrical connection between a single cylindrical conductor and a clamping bolt, said terminal clip being stamped from strip metal and bent crosswise of its midlength into a flaring U-shape with straight legs, said terminal clip having an opening centrally of its bight portion axially aligned with the adjacent ends of substantially smooth non-threaded adjacent faces of opposed long channels of semi-circular cross-section stamped into and extending lengthwise of the clip legs and freely receptive of the conductor to be clamped as the conductor is inserted axially through said opening and between the flaring legs of said clip, at least one pimple-like protuberance projecting inwardly from the bottom of at least one of said channels and positioned to bite into a conductor extending through said opening into juxtaposition with said protuberance lengthwise of and between the legs of said strip as said flaring legs are pressed into parallelism against the opposite sides of a conductor, aligned openings through said legs near the free ends thereof for the reception of clamping means for closing said legs against the opposite sides of a conductor, said U-shaped strip and said pimple-like protuberance being tempered to render said clip highly resilient and all portions thereof substantially harder than the hardness of the conductor to be clamped, and the free ends of said legs having a pair of aligned openings for fastener means to force said legs toward one another whereby the forced closing of said legs against a conductor forces said pimple-like protuberances to penetrate into the conductor and whereby said resilient legs relax the grip on a conductor as clamping pressure between the free ends of said legs is relaxed.

4. A solderless terminal clip as defined in claim 1 characterized in that the axes of said channels are similar, non-linear and effective when clamped closed against the similarly shaped non-linear end of a conductor to prevent axial rotation of the conductor relative to said terminal strip.

9. A solderless terminal clip as defined in claim 1 characterized in the provision of adapter means for converting said clip to grip a conductor of smaller diameter than can be clamped between said channels comprising a split sleeve metal having an O.D. corresponding generally with the shape of said channels and an I.D. having a loose telescopic fit with the particular size of conductor to be used therewith.

11. A solderless terminal clip as defined in claim 10 characterized in that said dimples are diametrically opposed to one another and spaced substantially equidistantly from the opposite sides of the split in said sleeve.

14. A solderless terminal clip as defined in claim 1 characterized in the provision of a plurality of adapter sleeves selectively usable to clamp conductors of different respective sizes between the channels extending lengthwise of the legs of said clip, said adapter sleeves having O.D. complemental to the juxtaposed surfaces of said channels and different I.D.''s corresponding to that of respective conductors all smaller than the diameter of said channels along said clip legs.

18. A solderless terminal clip of resilient tempered strip metal of divergent U-shape prior to clamping about the exposed end of a single solid conductor inserted between the legs of said clip through an opening in the bight portion thereof, said clip legs being straight and formed from uniform thickness strip stock and deformed lengthwise thereof to strengthen the same and to provide shallow juxtaposed planar channels having generally smooth semi-cylindrical surfaces and a combined depth less than the diameter of the conductor to be clamped therebetween, said channels being free of threads and having one end in communication with said opening in the bight portion of said clip and the other end terminating short of the free ends of said clip legs, the cross sectional shape and size of said smooth semi-cylindrical channels being effective to provide a powerful grip on the juxtaposed surface of a conductor positioned therebetween as the smooth non-threaded surfaces of the clip legs are pressed into parallelism with one another and against a conductor therebetween, and means extending between the free ends of said legs to force the same toward one another to clamp a conductor immovably in place therebetween.

25. A terminal clip as defined in claim 23 characterized in that the free ends of said legs have aligned openings therethrough to receive a threaded clamping member.

26. A terminal clip as defined in claim 23 characterized in that said channels are of similar non-linear shape lengthwise thereof and adapted to seat the complementally shaped non-linear end of a conductor inserted through said opening in the bight portion of said clip.

27. A terminal clip as defined in claim 23 characterized in that the bottom of at least one of said channels is formed with radially disposed tempered sharp crested protrusion means harder than a conductor and effective to penetrate into a conductor as said legs are clamped against a conductor.