US2697213A - Solderless electric terminal - Google Patents

Description

Dec. 14, 1954 R. C. PATTON SOLDERLESS ELECTRIC TERMINAL Filed May 31, 1952 JNVENTOR.

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United States Patent SOLDERLESS ELECTRIC TERMINAL Ralph C. Patton, Providence; R. Ii, ass'ignor to Ifatton- MacGuyer'Coz, a'corpolation'of Rhode Island- Application May 31, 195-2, Serial No. 290,980 4 Claims. (Cl. 339-416 This invention relates to a solderless electric terminal and more particularly to a te'r'rrl'irial in which the crimping or holding means of the shank 18 formed prior to the insertion of the wire.

Solderless wire terminals in the past have employed various means of holding the wire conductor. These means have taken the form of cars which fold laterally over the end portion of the conductor and have used additional means such as detents pressed into the terminal after the ears have been folded or have employed ribs running laterally across the shank portion formed prior to the insertion of the wire to hold the wire securely.

One of the objects of this invention is to provlde an improved solderless electrical connector.

A further object of this invention 1s to pro-form a solderless wire terminal which will tend to 1am the wire against the arms of the shank portion.

Another object of this invention is to form the rib or holding portion of the shank prior to the insertion of the wire.

Another object of this invention is to form the terminals in strip form when so desired, but they may also be produced and applied as separate terminals.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a top plan view of the terminal afiixed to the end of an insulated wire;

Figure 2 is a bottom plan view of the reverse side of the terminal affixed to the wire;

Figure 3 is a top plan View of a modified form terminal with a single pair of arms;

Figure 4 is a plan view of the terminal in fiat sheet stock form;

Figure 5 is a sectional view taken on lines 5--5 of Figure 4;

Figure 6 is a sectional view taken on lines 6-6 of Figure 1;

Figure 7 is a plan view of the terminals in strip form showing the various stages of fabrication in one method of production; and

Figure 8 is a section view of a modified form of my terminal showing an alternate rib structure.

In proceeding with this invention, I provide a strip of sheet metal stock, cutting this stock by means of dies and bending it by forming tools to the shape desired for an electric terminal. During the die stamping process I form one or more ribs in the shank portion to co-operate with the arms that fold over the wire.

With reference to the drawings, 10 designates the lug or connector portion of the electric terminal, and 11 designates the shank portion of the terminal. The shank portion of the terminal is provided with arms 12 which are adapted to wrap around the wire as shown in Figures 1 and 3. In some cases it is also desirable to have additional arms which may wrap around the insulation. Both pairs of arms have edges diagonal to the main axis of the shank portion 11. Ribs 13 are formed between the extending arms 12 and 15, which are also diagonal or oblique to the axis of the shank portion 11 in a direction to co-operate with the diagonal extent of the edges of the arms as will hereinafter appear. A preferable form of the rib 13 is shown in Figure 5 where the metal has been struck 2,697,213 Patented. Dec.v 14, 1954 2 with a blunt-edged punchtogive a rounded form tothe rib; It isalso possible to form the rib such. as at 13' in Figure 8; In this form a shearing punch may be lightly struck against the sheet stock to partially shear the metal and raise it from the surrounding stock.

A- solid or standard wire is attached tothe shank portion by laying the wire over rib I3- and rolling and pressing arms 12 over and into engagement with the wire. Referring to Figures 1 and 2, it will be seen that the angleof the rib" 1'3 and the edge 14- of arms 12 is substantially parallel when the arms: are folded over the: wire. When the wire is pulled sufiiciently to ca-useit to' move lengthwise through the arms 12, the edge of the arms 14- and the rib 1'3 co-operate to urge the wire laterally thereby wedging it under one of the arms 12 which increases the frictional resistance be.- tween the wire and terminal and creates the effect of an extreme crimping force being applied by the terminal to the wire.

Referring more particularly to Figure 6, I show an enlarged view of the wire enclosed by arms 12 at the point of the rib 13. It is apparent from this view that in the preferred form of this invention wherein the edges 14 of arms 12 do not meet, the wire is forced into the space between edges 14 by the action of rib 13. The resulting configuration of the wire is such that when a lengthwise acting force is applied tending to disengage the wire from the terminal, the channeling effect created by the rib will tend to force the wire to the edge of the terminal underneath arms 12. This effect will also be present when two pairs of arms are used, the second pair enclosing the insulation. Arms 15 will force part of the insulation between their open space and form an identical channeling action to that present with the wire. Thus, with insulated wire and a two pair arm terminal, the force required to disengage the wire is greatly increased.

While a more positive action of channeling occurs when the edges 14 of arms 12 do not meet, it has been found that when the edges do meet, as may occur when certain wire sizes are used, the action of rib 13 alone is suflicient to greatly increase the resistance of the wire to being disengaged from the terminal over other rib structures which lie lengthwise or transverse to the wire. With the crimps and indentations used in the prior art, the entire holding power has been determined by the force used in the crimping process and the area of the crimp. In the present structure. however, the amount of force used to bend the arms over the wire is not an important factor, as should the wire begin to slip, an additional lateral force is inherently applied over an increasingly greater area as the wire wedges against the inner wall of arms 12 and causes greater friction to be applied.

Referring particularly to Figure 7, I show a strip of metal 20 which has passed through the first stage of the die forming operation and has a terminal hole 21 and ribs 13 formed therein. Passing on to the second stage of the die-cutting operation, the arms 12 and 15 have been formed and a lug portion 10 has been shaped. The third stage of the forming operation bends the arms 12 and 15 upwardly at substantially a right angle to the plane of the lug portion. Severing occurs by removing the web 22.

While I have described one method of producing this terminal, it is to be understood that various die-cutting operations may be substituted to provide a different SCCilICllCC and that the terminal may take several shapes.

claim:

1. A solderless electric terminal formed from sheet metal stock comprising a connector portion, a shank portion, arms on said shank portion extending in opposite directions transversely thcrefrom for folding about a wire, said arms when in the plane of said shanks having at least one edge extending diagonally to the axis of said shank and a rib in said shank portion extending on an opposite diagonal to the axis of the shank than the said edge of said arm, the said edge of said arm when in working position extending parallel to the rib so that a wire held between the folded arms and the shank portion will be deflected upwardly against the said diagonal edge and securely gripped, axial movement of the wire wedging the deflected portion against one of the arms.

2. A solderless electric terminal as in claim 1 wherein both edges of said arms are parallel and extend on the same diagonal, said edges when in working position being spaced so that the wire will be deflected upwardly between said edges.

3. A solderless electric terminal formed from sheet metal stock comprising a lug portion, a shank portion, arms extending from the shank portion for folding about a wire, said arms having at least one edge that extends obliquely to the axis of the shank portion, a projection in said shank portion extending obliquely to the axis thereof, said edge of said arm being substantially parallel to the oblique projection when in working position so that a wire held between the folded arms and the shank portion will be deflected upwardly against the oblique edge and securely gripped, axial movement of the wire wedging the deflected portion against one of the arms.

4. A solderless electric terminal as in claim 3 wherein both edges of said arms are parallel and extend on the same diagonal, said edges when in working position being spaced so that the wire will be deflected upwardly between said edges.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 962,921 Schneider June 28, 1910 1,262,155 Zimmerman Apr. 9, 1918 1,789,951 Terrell et al. Jan. 20, 1931 2,008,227 Reilly July 16, 1935 2,288,918 Parker July 7, 1942 2,483,424 Martines Oct. 4, 1949 FOREIGN PATENTS Number Country Date 271,613, Great Britain June 2, 1927

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