US3332054A

US3332054A - Electrical terminal with v-shaped barrel

Info

Publication number: US3332054A
Application number: US385165A
Authority: US
Inventors: Fernandes Jacinto
Original assignee: Thomas and Betts Corp
Current assignee: ABB Installation Products Inc
Priority date: 1964-07-27
Filing date: 1964-07-27
Publication date: 1967-07-18
Anticipated expiration: 1984-07-18

Description

.Fufiy 18, WW J. FERNANDES 3,332,054

ELECTRICAL TERMINAL WITH V-SHAPED BARREL Filed July 27, 1964 2 Sheets-Sheet l 2%M ZZZ 06 1 1%? J. FERNANDES 3,332,054

ELECTRICAL TERMINAL WITH V-SHAPED BARREL Filed July 27, 1964 2 Sheets-Sheet 2 TILEI- INVENTOR c/A cm'm frpm/vocs ado Wen United States Patent G 3,332,054 ELECTRICAL TERMINAL WITH V-SHAPED EAL Jacinta Fernandes, Elizabeth, N..l., assignor to The Thomas & Betts Co., Elizabeth, N..l., a corporation of New Jersey Filed July 27, 1964, Ser. No. 385,165 9 Claims. (Cl. 339-223) This invention relates to a new and improved electrical terminal, and more particularly to a new and improved electrical terminal of the type which is suitable for crimping onto one or more conductors.

Electrical terminals are Well known in the art and a wide variety of terminals for electrical conductors may be found in use. One type of such terminal is mechanically attached to a conductor by means of a crimping tool or other pressure device. This crimp type terminal generally comprises a tongue and a barrel. The tongue is adapted to be attached to another terminal, to a binding post or other such terminal device, and may be of any desirable form such as ring, spade, etc. The barrel of the terminal is adapted to be crimped onto the wire conductor and may include a portion to be attached to the conduct-or alone or in addition may also include a portion to be attached to the insulation of the conductor. The barrel of the terminal is so formed that the end of a wire may be easily inserted into the barrel of the terminal. The terminal is then crimped on to the wire by means of a suitable crimping tool.

In general, it is desirable that the crimping operation produce a crimped-on terminal that has good electrical contact between the wire conductor and the terminal so that during the life of the terminal, there is low power loss and a low voltage drop is maintained across the terminal and the terminal connection is resistant to corrosion and oxidation. It is also desirable that the crimped-on terminal be resistant to pull-out and vibration.

It has been found that voids between individual strands of a wire conductor are often formed during the crimping operation using known crimp type terminals. These voids are generally objectionable because, during the life of the terminal, oxidation of the copper strands will cause oxides to build up in the voids, thereby increasing the power loss and voltage drop across the terminal and decreasing the efiiciency of the terminal. It has also been found that in order to achieve a more compact crimp, substantially free of objectionable voids, it is desirable that, during the crimping operation, pressure be applied evenly over the surface of the barrel of the terminal.

In order to achieve these ends, the terminal of the present invention has been developed. According to the present invention, a terminal is provided which may have any known form of tongue but which has a unique V- shaped barrel which, when crimped on to a wire termination, will provide a terminal having substantially no voids between the strands of the wire terminated. During the crimping operation, it is preferable that the pressure be evenly distributed throughout the surface of the barrel. During the crimping operation, the V-shape of the barrel of the terminal causes the strands of the wire conductor to scrape against each other, thus aiding in scrubbing any oxides or other contaminants which are formed on the strands, loose from the surface of the strands. Where the barrel of the terminal is also serrated, the serrations in the wire grip portion of the barrel will also scrape the strands to loosen undesirable oxides. This scrubbing action eliminates the separate operation of cleaning the wire before termination as by dipping the wire end in nitric acid or the like.

It is thus an object of the present invention toprovide a new and improved electrical terminal for wire conductors wherein the terminal is vibration-proof and has greater pull-out strength.

It is a further object of the present invention to provide a new and improved electrical terminal for wire conductors wherein the termination is oxidation and corrosion-resistant, has low power loss and voltage drop, and has better contact between the wire conductor and the electrical terminal.

It is yet another object of this invention to provide a new and improved crimp type electrical terminal for wire conductors wherein the barrel of the electrical terminal forms a homogeneous mass with the strands of the wire and wherein there is a minimum of voids between the strands of the terminated wire conductor.

Other and further objects will become apparent from the following detailed description and drawings wherein:

FIG. 1 is a perspective view of one embodiment of the present invention in blank form;

FIG. 2 is a perspective view of the embodiment of FIG. 1 showing the terminal having a V-shaped wire grip barrel;

FIG. 3 is an end elevational view of the embodiment of FIGS. 1 and 2 showing the V-shaped barrel portion of the terminal;

FIG. 4 is another embodiment of the present invention;

FIG. 5 is yet another embodiment of the present invention;

FIG. 6 is a partial perspective view of the embodiment of FIG. 5 showing the barrel with a V-shape configuration;

FIG. 7 is a plan view of yet another embodiment of the present invention;

FIG. 8 is a perspective view of the embodiment of FIG. 7 showing the barrel with a V-shape configuration;

FIG. 9 is a perspective view of the crimping tool before a terminal of the present invention is crimped on to the wire end of an electrical conductor;

FIG. 10 is a sectional view of the wire to be terminated placed in the barrel portion of a terminal of the present invention before the crimping operation takes places;

FIG. 11 shows a sectional view of the wire of FIG. 10 during the crimping process;

FIG. 12 shows a sectional view of the wire of FIG. 10 after the terminal has been crimped on to the end of the wire; and

FIG. 13 shows a sectional view of a known type terminal crimped on to the end of a wire after the crimping operation.

More particularly now referring to the figures in which certain preferred forms of the present invention are shown, FIG. 1 shows an electrical terminal 10 having a tongue 12 of ring-shape and a barrel 14. Tongue 12 has a neck 16 integral with barrel 14. Terminal 10- may be of any suitable conducting metal such as copper, brass, or the like. As shown in FIG. 1, terminal 10 has been severed from a strip of terminals and is in blank form. The severing of terminal 10 may take place before, during, or after the crimping process. Barrel 14 is shown substantially in the shape of a parallelogram having its longitudinal axis at an angle to the longitudinal axis of the terminal. This provides for better termination of the terminal on a wire lead during the crimping operation.

FIG. 2 shows the terminal of FIG. 1 after the barrel of the terminal has been given a V-shape configuration. The V-shape configuration, shown more clearly in FIG. 3, has been found to provide a more homogeneous termination with a minimum of voids between strands of the wire conductor terminated and a termination wherein the final set of terminal and. wire is one of compression with pressure evenly distributed over the area of the termination.

As shown in FIG. 3, the V-shape barrel comprises a V-shaped lower

portion having sides

18 and 20 converging in an angle at the bottom of the barrel, and

sides

22 and 24 which form angles respectively with

sides

18 and 20. As shown in FIG. 2,

sides

22 and 24 are shaped substantially in the form of triangles, whereas

sides

18 and 20 are shaped substantially in the form of parallelograms. During the crimping operation, the strands of the wire conductor are gathered in by

sides

22 and 24 and compressed into a single homogeneous mass. Additionally,

sides

22 and 24 overlap the wire lead such as to produce a crimp wherein the adjacent edges of

sides

22 and 24 form a diagonal seam which is closed.

Although the included angle formed by

sides

18 and 20 is not critical and may be any angle less than 180", but more than it has been found that an included angle of about 60 provides a termination with excellent electrical characteristics. However, in determining the included anglev for the barrel of a particular terminal, the combination of angle, size of barrel and size or diameter of Wire must be taken into account. For example, it has been found that the included angle of the barrel should preferably be about 60 when a .302 barrel is used in terminating an 18 A.W.G. wire having 16 strands.

FIG. 4 shows an embodiment of the present invention before a V-shape has been placed in the barrel wherein the wire grip barrel is serrated. As shown in FIG. 4, the serrations may be transverse grooves 26. It will be understood that any configuration of serrations well known to those skilled in the art such as herringbone patterns, criss-cross patterns, etc., may be used in place of the parallel transverse grooves of FIG. 4.

The embodiment of the present invention shown in FIGS. 5 and 6 is a modification of that shown in FIGS. 1-3, wherein the barrel includes, in addition to the Wire grip portion, an insulation grip portion 28. The insulation grip portion is also formed in a V shape having lower sides that converge in an included angle of less than 180 but more than 0. The included angle of the insulation grip portion of the barrel is preferably the same as the included angle of the wire grip portion of the barrel.

Referring now to FIGURES 7 and 8, there is shown another embodiment of the present invention in which the barrel consists of a wire grip portion substantially in the shape of a parallelogram. having a longitudinal axis that is parallel to and preferably coincidental with the longitudinal axis of the terminal itself. The terminal of FIGS. 7 and 8 consists of a tongue 12 and a barrel 14,

the barrelhaving sides 30 and 32 which converge in an included angle of less than 180 but more than 0.

Sides

34 and 36 form angles respectively with

sides

30 and 32 and provide the upper portion of the wire grip. It will be understood that although the embodiments of FIGS.

1, 4 and 7 are shown as having a barrel with a wire grip portion onl these embodiments may also be provided with insulation grip portions.

Referring now to FIG. 9, there is shown an electrical conductor 40 having an insulation 42 and a wire 44,

wire 44 being of electrically conductive material such as copper or the like, and comprising a plurality of strands 48. It will be understood that wire 44 could also bea solid conductor or any other well known type of conductor. Electricalconductor40 is shown as having its end stripped of insulation 42 with wire 44 positioned in barrel 50 of terminal 52..Terminal 52 is shown as having a ring tongue 54. Barrel 50 has converging

sides

56 and 58 which form an included angle of less than 180 but more than 0. Sides 60 and '62 form angles respectively withsides 56-and 58. Terminal 50 with wire end 44 of electrical conductor 40 is shown resting on an anvil 64. Also shown is a crimping tool 66 in raised position ready for crimping terminal 52 on to the end of electrical conductor 4t In order to obtain a properly crimped terminal, it is preferable that a crimping device be utilized that produces a confined crimping action. Such a crimping action contemplates applying pressure to the entire periphery of the barrel during at least the final stages of the crimping action.

Referring now to FIGURES 10, 11 and 12, there is respectively shown a cross-section of the V-shaped barrel.

of the present invention with a wire positioned in the barrel before, during, and after the preferred crimping operation has been completed. In FIG. 10 there is shown terminal barrel 68 having

sides

70 and 72 converging to an included angle of approximately 60". Side 74 forms an obtuse angle with side 70, as does side 76 with side 72

sides

74 and 76 providing the upper portions of the crimped barrel. A multi-stranded wire 78 comprised of strands 80 is shown positioned in barrel 68. Barrel 68'is shown positioned on anvil 82.

Referring now to FIG. 1l,1there is shown a crimping tool 84 during the crimping operation. During the downward movement of tool 84, the upper surface 86 of nest 88 of tool 84 causes

sides

74 and 76 to close about strands 80 of wire 78.'Strands 80 are thus forced down into the V- shaped portion formed by

sides

70 and 72. During the crimping operation, while tool 84 is descending, strands 80 tend to scrape against each other and thus provide scrubbing action to remove oxides and other contaminants possibly present on strands 80. Similarly, the sides of barrel 68, especially if serrated, will also aid in this cleaning operation.

As tool 84 continues to descend, the pressure is evenly distributed throughout the periphery of the barrel, causing extrusion of the strands of the conductor to take place parallel to the crimp body and forcing strands 80 of wire 78 to form a homogeneous mass With barrel 68. This is shown more clearly in FIG. 12. As shown, strands 80 of wire 78 are substantially free of voids. The crimped terminal in FIG. 12 is to be contrasted with that shown in FIG. 13.

Referring to FIG. 13, there is shown a crimping device having a nest 94 and a tooth 96. A multi-stranded wire 90 is shown after a known type terminal 92 has been crimped onto wire 90. Since such a crimping device does.

not apply pressure throughout the entire periphery of the barrel during the crimping operation, a crimp results in which the final set of the crimp is in compression in the vertical direction and extrusion in the horizontal direction. As shown, voids between strands will cause oxides to build up during the life of the crimp, thus cutting down onthe efficiency of the crimped terminal. In order to thus increase the efiiciency of the crimp using the terminal of the present invention, it is preferable that a con-, fined crimping operation be used to terminate wires by means of the terminal of the present invention.

It is to be understood that although preferred embodiments of the present invention have been described hereinabove and have been shown in the drawings, the present invention is not to be limited thereby but rather by the appended claims.

I claim:

1. An electricalterminal adapted to be-crimped onto at least one electrical conductor having a plurality of wire strands comprising a tongue and a substantially V- shaped barrel, said barrel being adapted to be crimped onto said at least one conductor, said substantially V- shaped barrel having a lower portion comprising a first side and a second side, said first and second sides being integral and converging to form an included angle of less than but more than 0, the distance between said upper portions of said first and said secondsides being less than the width of said at least one conductor, said at least conductor being adapted to rest on said upper portions of said first and second sides prior to crimping, suchor contaminants thereon, said barrel further having an upper portion comprising a third side and a fourth side, said third side being integral with and forming an included angle of less than 180 but more than 90 with said first side and said fourth side being integral with and forming an included angle of less than 180 but more than 90 with said second side.

2. The electrical terminal of claim 1 wherein the inner surface of said barrel is serrated.

3. The electrical terminal of claim 1 wherein said first and said second sides of said barrel are shaped substantially in the form of a parallelogram and said third and said fourth sides of said barrel are substantially shaped in the form of a triangle.

4. The electrical terminal of claim 1 wherein said sides of said barrel are substantially in the form of a parallelogram.

5. An electrical terminal adapted to be crimped onto at least one electrical conductor comprising a tongue and a substantially V-shaped barrel, said barrel comprising a substantially V-shaped conductor grip portion adapted to be crimped onto the wire of said at least one electrical conductor having a plurality of wire strands and an insulation grip portion adapted to be crimped onto the insulation of said electrical conductor, said conductor grip portion of said substantially V-shaped barrel having a lower portion comprising a first side and a second side, said first and second sides being integral and converging to form an included angle of less than 180 but more than 0, the distance between said upper portions of said first and said second sides being less than the width of said at least one conductor, said at least one conductor being adapted to rest on said upper portions of said first and second sides prior to crimping, such that during the crimping operation, the strands of said at least one conductor are forced into the space between the lower portions of said first and second sides, thus causing said strands to scrape against each other to remove oxides or contaminants thereon, said conductor grip portion of said barrel further having an upper portion comprising a third side and a fourth side, said third side being integral with and forming an included angle of less than 180 but more than 90 with said first side and said fourth side being integral with and forming an included angle of less than 180 but more than with said second side.

6. The electrical terminal of claim 5 wherein the inner surface of said wire grip portion of said substantially V- shaped barrel is serrated.

7. The electrical terminal of claim 5 wherein said insulation grip portion is substantially V-shaped, said insulation grip portion having a lower portion comprising a first side and a second side, said first side and said second sides converging to form an included angle of less than but more than 0, said insulation grip portion further having an upper portion comprising a third side and a fourth side, said third side being integral with and forming an included angle with said first side and said fourth side being integral with and forming an included angle with said second side.

8. The electrical terminal of claim 7 wherein said first and said second sides respectively of said wire grip portion and said insulation grip portion of said barrel are shaped substantially in the form of a parallelogram and said third and fourth sides respectively of said wire grip portion and said insulation grip portion of said barrel are shaped substantially in the form of a triangle.

9. The electrical terminal of claim 7 wherein said sides respectively of said wire grip portion and said insulation grip portion of said barrel are shaped substantially in the form of a parallelogram.

References Cited UNITED STATES PATENTS 2,747,171 5/1956 Martines 339-276 2,802,257 8/1957 Holtzapple 339-223 X 3,015,684 1/1962 Schneider 339276 X 3,078,331 2/1963 Newman 174-90 X 3,112,150 11/1963 Hammell 339-223 X 3,248,686 4/1966 Ruehlemann 339-223 X FOREIGN PATENTS 529,403 6/1954 Belgium. 883,154 3/1943 France.

MARVIN A. CHAMPION, Primary Examiner. PATRICK A. CLIFFORD, Examiner.

Claims

1. AN ELECTRICAL TERMINAL ADAPTED TO BE CRIMPED ONTO AT LEAST ONE ELECTRICAL CONDUCTOR HAVING A PLURALITY OF WIRE STRANDS COMPRISING A TONGUE AND A SUBSTANTIALLY VSHAPED BARREL, SAID BARREL BEING ADAPTED TO BE CRIMPED ONTO SAID AT LEAST ONE CONDUCTOR, SAID SUBSTANTIALLY VSHAPED BARREL HAVING A LOWER PORTION COMPRISING A FIRST SIDE AND A SECOND SIDE, SAID FIRST AND SECOND SIDE BEING INTEGRAL AND CONVERGING TO FORM AN INCLUDED ANGLE OF LESS THAN 180* BUT MORE THAN 0*, TH DISTANCE BETWEEN SAID UPPER PORTIONS OF SAID FIRST AND SAID SECOND SIDES BEING LESS THAN THE WIDTH OF SAID AT LEAST ONE CONDUCTOR, SAID AT LEAST CONDUCTOR BEING ADAPTED TO REST ON SAID UPPER PORTIONS OF SAID FIRST AND SECOND SIDES PRIOR TO CRIMPING,SUCH THAT DURING THE CRIMPING OPERATION, THE STRANDS OF SAID OF LEAST ONE CONDUCTOR ARE FORCED INTO THE SPACE BETWEEN THE LOWER PORTIONS OF SAID FIRST AND SECOND SIDES, THUS CAUSING SAID STRANDS TO SCRAPE AGAINST EACH OTHER TO REMOVE OXIDES OR CONTAMINANTS THEREON, SAID BARREL FURTHER HAVING AN UPPER PORTION COMPRISING A THIRD SIDE AND A FOURTH SIDE, SAID THIRD SIDE BEING INTEGRAL WITH AND FORMING AN INCLUDED ANGLE OF LESS THAN 180* BUT MORE THAN 90* WITH SAID FIRST SIDE AND SAID FOURTH SIDE BEING INTEGRAL WITH AND FORMING AN INCLUDED ANGLE OF LESS THAN 180* BUT MORE THAN 90* WITH SAID SECOND SIDE.