US3539977A - Electrical terminal - Google Patents

Description

M. 10, 1970 V H. wosn'rz I snowmen TERMINAL Fund New. 4. 196B 'mwsm.

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INVENTOR.

Ham; Wdcriz 3,539,977 ELECTRICAL TERMINAL Hans Woertz, Basel, Switzerland, assignor t Oskar Woertz, Inh. H. & O. Woertz, Basel, Switzerland Filed Nov. 4, 1968, Ser. No. 773,154

Claims priority, application Switzerland, Nov. 13, 1967,

Int. Cl. H01r 7/14, 9/12 US. Cl. 339-198 2 Claims ABSTRACT OF THE DISCLOSURE An electrical terminal for securing a conductor thereto having a casing with a pressure member therein and a spring element having longitudinal edge portions and a saddle-shaped configuration mounted in the casing.

This invention relates to an electrical terminal to secure conductors thereto.

The present invention relates to an electric terminal comprising, between a pressure member and a supporting surface, a chamber for accommodating one or more conductors, and comprising a spring element which forms a boundary surface of said chamber and which is made from a strip of resilient material.

In known terminals of the stated kind, wherein conductors are clamped between a leaf spring, which is curved in the unloaded condition in the longitudinal direction and bears upon a supporting surface, and a pressure member, having a flat pressure surface and subjected to pressure from a screw, there exists the danger that with two round conductors of dissimilar diameter, only that conductor having the greater diameter will be properly clamped, and the conductor having the smaller diameter will be inefficiently clamped, or not clamped at all.

The object of the invention resides essentially in eliminating the stated disadvantage and in providing a terminal of the kind that is so designed that even an individual conductor can be clamped in a definite and secure position.

In accordance with the invention, this latter is achieved essentially by at least single longitudinal edge portions of the spring elements, which are located in the zone of action of the pressure member, and projecting towards the conductor-receiving chamber in such a manner that that surface of the spring element presented to the chamber has the form of a V, open toward the chamber, in the vertical projection and in the longitudinal direction of the spring element.

Further objects will be apparent from the following description when considered in connection with the accompanying drawing in which:

FIG. 1 is a part side elevation and part sectional view of a terminal;

FIG. 2 is a section taken on line IIII of FIG. 1, in the direction of the arrows; and

FIG. 3 is a side view partly in section showing two terminals which are contained in an insulating body and have, as a pressure member, a web common to both of them.

The terminal in FIGS. 1 and 2 has a conductor-receiving element or casing 10, which is in the form of a piece of rectangular tubing. Inserted into the cavity 11 of the conductor-receiving element are rod-shaped pressure member 12 of rectangular cross-section and a spring element 13. Positioned between the pressure member 12 and the spring element 13 is the conductor-receiving chamber 14, into which one or more electric conductors can be pushed. A screw 15 acts upon that face of the pressure member 12 remote from the spring element 13, and this screw element is contained in a taped hole 16 in one of United States Patent @flice 3,539,977 Patented Nov. 10, 1970 the narrow sides of the conductor-receiving element 10.

The spring element 13 is made from a strip of resilient material and is saddle-shaped in the zone of action of the pressure member 12, the longitudinal edge portions 17 and 18 of the spring element 13 being bent upwards toward the chamber 14, so that the spring element 13, in the zone of action of the pressure member 12, is of V-shaped crosssection open towards the conductor-receiving chamber. By saddle-shaped is meant that the spring element 13 has a double curved shape in the zone of action of which one curve being in the longitudinal direction of the element and the other being in the transverse direction, Instead of being formed into a V-shaped cross-section in the entire zone of action of the pressure member 12, the spring element 13 can be so shaped in this zone that only individual longitudinal edge portions project toward the chamber 14, so that that surface of the spring element presented to the chamber 14 has the shape of a V, open toward the conductor-receiving chamber 14 in the vertical projection in the direction of the conductors that are to be pushed in. In a spring element of this type, the two longitudinal edge portions, for example, can be corrugated, and corrugation of one of the longitudinal edge portions being phased oppositely, in the longitudinal direction, to the corrugation in the other portion.

In the present embodiment, the surface of the spring element 13, that is presented to the conductor-accommodating chamber 14, contains notches (not illustrated) which extend transversely of the longitudinal direction of the spring element 13. The notches are for the purpose of increasing the friction between the spring element 13 and the conductor or conductors to be clamped in the terminal.

In the unloaded condition, the spring element 13 lies on the outer edges of the narrow inner face 19 of the conductor-receiving element 10, opposite the screw 15. Both end portions 20 and 21 of the element 13 are bent away from the pressure member 12. One end portion 20, which embraces the conductor-receiving element 10, is bent round through an angle of almost so that the spring element 13 is thereby attached to the conductor-receiving element 10. The other end portion 21 of the element 13 is bent at approximate right angles to the supporting surface 19 and, directly adjacent the point of bend 22, has two incisions or cut-out portions 23, which reduce the cross-section.

FIG. 3 shows two terminals, each as in FIG. 1, which are contained in an insulating member 24 and which incorporate, as pressure members 12, a web 25 which is common to both terminals. The terminal disposed on the left in the insulating member 24, together with the conductor-receiving element 10a, is thus completely enclosed, that is, the conductor-receiving element 10a is pulled up against the web 25 b means of the screw 15, while the terminal shown on the right, together with the conductor-receiving element 10b, is fully open and ready to receive conductors. Pieces 26 of flexible insulating tubing are pushed over the end portions 21 of the spring elements 13, which portions are bent at approximately rightangles. As can be seen from FIG. 3, the downwardly angled end portions 21 of the spring elements 13 prevent unintentional insertion of conductors into the cavities 27 below the conductor-receiving elements 10a and 10b in the insulating member 24. The flexible insulating tubes 26, pushed over the end portions 21 of the spring elements 13, thereby perform the function of reducing the spaces between the longitudinal edges of the angled end portions 21 and the inner face of the side wall of the insulating member 24 and the outer face of the side wall of a closure member, not illustrated in the drawing, or of an adjacent insulating member.

The way in which the terminal is used and works when clamping two conductors of round cross-section and dis- 12 and the spring element 13.

similar diameters, 'the sum of which is less than the width of the chamber in "which they are received, is"a's follows: with the terminal open, the two conductors are inserted side-by-side into the chamber 14. The thicker conductor, for example, thereby lies on the longitudinal edge portion 17 and the thinner conductor on the other longitudinal edge portion 18 of the spring element 13. When the screw is tightened, pressure is first applied, by way of the pressure member 12 and the thicker conductor, to the longitudinal edge portion 17 of the spring element 13 and this edge portion is pressed toward the supporting surface 19 of the conductor-receiving element 10. As a result of the lateral play of the spring element 13 in the conductor-receiving element 10, the spring element 13 tilts on the" supporting surface 19 in such a way thatthe other;longitudinal edge portion 18 is pressed upwards against 'the thinner conductor. In this way, the thinner conductor is also clamped between the pressure member The'spring element 13 thus not only performs the function of a safety means for preventing loosening of a tightened screw 15, but it also takes over the role of matchingtlie cross-section of the conductor-receiving chamber to thecross-sectional forms of the conductors that are to be clamped. p g I 1 Since, when the spring element 13 tilts on the supporting surface 19, as described, the angled end portion 21 of the'spring element '13 is swung out of its original posi tion, there exists the danger of the end portion 21 of the spring element 13 applying unwanted pressure on the side wall'ofthe'insulating elements 24or of the required tilting of the spring element being partially impeded; In the present embodiment, this"dangeris'countered'by the cutout parts23 which 'i''duce the cross-section of the end portion 21 adjacent th'poiritof'bend 22 and which provide a nominal bending point which can be deformed even by small forces." I

Iclaim: I

1. Electric terminal comprising a casing having a supporting surface, a pressure member in" the casing, said casing having a chamber for receiving at least one conductor, and a spring element forming a boundary surface of the conductor-receiving"chamber and which is formed from a strip' of resilient material, said spring element having longitudinal edge portions which are located in a Zone of action of the pressure member and projecting'toward and into the conductor-receiving chamberso that a surface of the spring element presented to the conductor-receiving chamber having the form of a V, open toward the conductor-receiving chamber in the perpendicular projection as to the longitudinal direction of the spring element, the spring element being eurved' in the zone of action of the pressure member in the longitudinal direction of the spring element.

2. Electric terminal comprising a casing having a supporting surface, a pressure member in the casing, said casing having a chamber for receiving at least one conductor, and a spring element forming a boundary surface of the conductor-receiving chamber and which is formed from a strip of resilient rn'aterial,'saidspring element having longitudinal edge portions which are. located in a zone of action of the pressure member a'nd'projecting toward and" into the conductor-receiving chamber so that a surface of the spring element presented to the conductor-receiving chamber having the form'of a V, open toward the conductor-receiving chamber" in the perpendicular pro-,

jection as to the longitudinal direction of the spring element, the spring element having an end portion bent away from the casing outside a bearing surfaceof the casing at least approximately at right angles to said surface, and at least one of the longitudinal edges of the bent-away end portion having atleast one cut-out portion to reduce the cross-section thereof adjacent a point where the spring element is bent.

References Cited UNITED STATES PATENTS 6/1931 Bormann et al. 2,805,402 9/1957 Lucal 339-14 2,950,457 8/1960 Slater 339-41 3,124,409 3/1964 Nis ula., 339 41 I 3,246,283 4/1966 Huska p l; FOliEICihli PATENTS 736,802 6/1943 Germany.

MARVIN A. CHAMPION, Primary Examiner R. A. HAFER, Assistant Examiner US. Cl. X.R. 339-252, 272

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