US3905671A

US3905671A - Clamping connector

Info

Publication number: US3905671A
Application number: US448297A
Authority: US
Inventors: Ernst-Friedrich Lechner
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1973-03-07
Filing date: 1974-03-05
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16
Also published as: LU69563A1; BE811924A; FR2220888A1; PL89870B1; DE2311295B2; NL7402822A; CS168696B2; FR2220888B1; NO134075B; IT1003698B; RO72369A; DE2311295C3; IE38919B1; IE38919L; DE2311295A1; DK136286B; JPS50387A; DK136286C; SE389946B; GB1448522A

Abstract

An improved clamping connector of the type having a dome-shaped arch and which is used to establish an electrical clamping connection between a rectangular equipment connector pin and a wire-type conductor, in which the two sides of the dome-shaped central portion of the clamp are provided with window cutouts, from which prongs protrude toward the interior of the clamp, thereby preventing the conductor or conductor bundle from turning aside or shifting during or after clamping.

Description

United States Patent [191 Lechner [4 1 Sept. 16, 1975 CLAMPING CONNECTOR [75] Inventor: Ernst-Friedrich Lechner, Erlangen,

Germany [73] Assignee: Siemens Aktiengesellschaft, Munich,

Germany [22] Filed: Mar. 5, 1974 [2]] Appl. No.: 448,297

[30] Foreign Application Priority Data Mar. 7, 1973 Germany 2311295 [52] US. Cl 339/95 R; 339/244 R; 339/258 S [51] Int. Cl. HOIR 13/24 [58] Field of Search....'... 174/84 C, 94 R; 339/97 R, 339/97 C, 223, 244 R, 256 R, 256 C, 256 SP,

258 R, 258 C, 258 S, 273 R, 273 F, 276 R,

[56] References Cited UNITED STATES PATENTS 2,783,442 2/1957 Burnosky 339/97 C 3,251,022 5/1966 Hammell 339/256 SP 3,283,289 1 H1966 Cobaugh 339/97 R X 3,660,806 5/1972 De Stephan 339/256 SP 3,828,298 8/1974 Schumacher 339/223 R OTHER PUBLICATIONS lBM Technical Disclosure Bulletin, Electrical Connector, Cargill et al., Vol. 4, No. 8, Jan. 1962, page 5.

Primary Examiner-Roy Lake Assistant ExaminerNeil Abrams Attorney, Agent, or Firml(enyon & Kenyon Reilly Carr & Chapin 9 Claims, 6 Drawing Figures CLAMPING CONNECTOR BACKGROUND OF THE INVENTION This invention relates to connectors in general, and more particularly to an improved clamping connector for establishing an electricconnection between a rectangular connector pin and a wire type conductor..

Clamping connectors of this general nature are disclosed in German Auslegeschrift No. 1,290,211, particularly on FIG. 25. These connectors consist of an approximately U-shaped elastic electrically conductive clamp which can be pushed and pressed onto a rectangular connector pin, together with a, wiretype conductor, using a tool. The two free leg ends of the clamp are bent inward to form approximately a semicircle, and are braced against one of the faces of the pin, with the central portion of the clamp pressed onto the opposite pin face. A conductor which is inserted between the central portion and the face of the pin is held securely .in reliable contact therewith. In order that it can also hold relatively large conductor cross sections or bundles of wire, i.e., stranded wire, the central portion of the clamp has a dome-shaped, outward protruding portion, with the wire bundle inserted in the cavity formed thereby. I

This previously known clamping connector which is of elongated, sleeve-like design, has within the channel formed by the dome-shaped bulge, a plurality of, inwardly directed creases extending crosswise to form projections and depressions to increase contact pressure with the wire when the clamping connector is clamped in place. While this arrangement does make it difficult to pull the conductor out of the dome-shaped cable channel after clamping, in use, it has been discovered thatafter apparently satisfactory clampingand possibly because during the course of time, the resilience of the clamping connector diminishes, lateral dis placement of the clamped wire bundle inside the domeshaped bulge occurs and therewith a loosening of the clamping. Such is particularly frequent if the clamped wire conductor must be moved back and'forth, particularly where such movement is lateral. It will be recognized that such can occur during subsequent manipulation such as lacing, sorting and wiring. Asa result, insufficient contact between the conductor and the connector pin and higher resistance is experienced. In some cases, a complete open circuit at the electrical connection can occur. In view of the great number of clamping connections of this nature which are required with present day sophisticated electronic equipment, considerable malfunctioning can occur which can cause serious problems since many of these electronic control devices operate at low voltages. As a result, a great deal of time can be spent in the elimination of such faults and correcting the electrical connection.

Thusfit can be seen that thereis a need for an improved connector Of this nature, which avoids these problems and insures reliable contact between the connector pin and the wire clamped thereto.

SUMMARY OF THE INVENTION The present invention provides such a clamping connector. Starting with the previously described clamping connector, which has a dome-shaped bulge, into which the wire to be clamped is inserted, the present invention includes on each side of the dome, the cutting out of window portions from which prongs are directed toward the interior of the clamp. These prongs prevent the conductor or conductorbundle from turning aside or shifting during or after clamping. The prongs are angled inwardly about the lower edgeof the cutout, i.e., the one away from the top of the dome, or can be bent inwardly with a curvature.

It isparticularly desirable to select the window length on each side of the dome and thereby, the length of the prongs, such that it can be pressed in, in such a manner that the ends of the prongs rest on the surface of the pin after clamping. In order to prevent the prongs from being pushed sideways during clamping, the ends of the prongs may be pointed, or a triangular window cutout used. Alternatively, the prongs may be angled inwardly around the lower window edge as well as outwardly about a further edge lying transversely to the longitudinal axis of the prongs atabout half the length of the prongs, or can be curved in the shape of an S. This latter design is particularly advantageous because the prongs then insert themselves between the wire bundle and the surface of the pin during the clamping operation, so that after the clamping the prongs are wedged between the conductor and the surface of the pin. It is 'BRIEP DESCRIPTION OF THE DRAWINGS "FIG. la is a perspective view of a first embodiment of the clamping connector of the present invention.

g FIG. lb is a cross sectional view of the embodiment of FIG. 1.-

FIG. 2a is a perspective view of the second embodiment of the clamping connector of the present invention.

FIG. 2b is a cross sectional view of the embodiment of FIG. 2a.

FIG. 3a is a perspective view of a third embodiment of the present invention.

FIG. 3b is a cross sectional view of the clamping'connector of FIG. 3a.

DET ILED DESCRIPTION OF THE PREFERRED I EMBODIMENT As illustrated by FIGS. la and lb, a clamping connector 2 is pushed onto a rectangular shaped connector pin 1. The clamping connector 2 has a shape which is approximately that of a U-shaped sleeve, including

legs

3 and 4 which are bent inwardly at their

free ends

5 and 6 to form respective semicircles which rest on the underside 7 of the connector pin 1. The top portion of the clamping connector 2 has a dome-shaped central portion 8 which is arched outwardly and into which is inserted a conductor 9 made up of stranded wires 10. The dome portion 8 presses the stranded wires of conductor 9 onto the surface 11 of the connector pin. As illustrated, the sides of the dome are provided with window cutouts 14 to form prongs which are directed inwardly and downward, with the ends 16 of the prongs resting on the surface 11 of pin 1. Through this measure, the stranded wires 10 of the cable 9 are held from any lateral displacement within the dome 8, due to a clawing engagement between the ends of the prongs and the surface of the pin. As is clearly shown on the right hand side of FIG. lb, this is a result of the end 16a of the prongs resting on the surface 11 of pin 1.

This claw engagement of the prong ends 16 on the pin surface 11 canbe increased by sharpening the prong ends shown by the prong ends 16/) on the lefthand side of FIG. lb, or by providing instead of rectangular cutouts 14, triangular cutouts, to result in triangular prongs.

In cases where scratching of the pin surface 11 must be avoided because of the-possibility of forming chips, a design of the clamping connector as illustrated by FIGS. 2a and 2h ispreferable. In this embodiment, the prongs 15' are angled off or curved, first inwardly about the lower edge of cutout I4 and, at about half the prong length, then angled outwardly so that the end pieces I6" of the prongs will be approximately parallel to the pin surface II and will be wedged between the stranded wire 10 of cable 9.

FIG. 3-illustrates a further embodiment of the invention in which the shape and length of the prongs are chosen so that the prong ends 16" meet after clamping. Iniorder to achieve this, the cutouts 14" must extend almost to the top 17 of the-dome 8, leaving only narrow webs l8. Alternatively, a webless continuous opening extending across the

sides

12 and 13 and the top of the dome 8 may be formed. Depending on the length of the clamping connector 2, a plurality of such continuous cutouts may be provided, each having prongs 15" which grip the conductors I0 from below. Through the tension which is then exerted on the dome 8 through clamping, the conductors 10 are held in an immovable fashion by the two portions of the dome extending completely around the conductor.

Thus, an improved clamping connector for clamping wires and the like to a square or rectangular connector pin has been shown. Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made, without departing from the spirit of the 1 be limited solely by the bent inwardly in approximately semicircular form and contacting one of the lateral faces of the connector pin, with the bottom protion of the U-shaped clamp adjacent the opposite lateral'face of the connector pin having an outward arch in the shape of a dome formed therein to form, with said'opposite face, a channel to receive the conductor, after which saidclamp may be subjected to a clamping force to affix the conductor in place, wherein the improvement comprises at least two window cutouts, one being made on each side of the domed portion, remote from the ends of the dome, formed by at least two circumferential cuts in the dome, the cuts extending to at least near the dome top, with the window cut out from the clone bent downward and inwardly at the lower uncut edge of the window to form prongs protruding toward the interior of said channel and together'with the dome-shaped arch at least partially clamping the conductor to prevent the conductor from turning aside or shifting during or after clamping.

2. A Clamping connector according to claim I wherein said prongs are curved and bent inward. 3. A Clamping connector according to. claim 1 wherein the length of the prongs is chosen so that after clamping, the prong ends rest on the surface of the connector pin.

4. A Clamping connector according to claim 3 wherein the ends of the prong are pointed.

5. A clamping connector accorting to claim I wherein said prongs are angled off inwardly about the lower edge of the cutout and then outwardly about a line transverse to the longitudinal axis of the prong at approximately half the length of the prong.

6. A Clamping connector according to claim 1 wherein said prongs are curved in an S-shape.

'7. A Clamping connector according to claim 5 wherein the length of the prongs is such that the prongs are wedged between the conductor and the surface of the conductor pin after clamping.

'8. A Clamping connector according to claim 6 wherein the length of the prongs is such that the prongs are wedged between the conductor and the surface of the conductor pin after clamping.

9 A Clamping connector according to claim 8 wherein the length of the prong is selected so that the ends of the prongs on each side abut after clamping.

Claims

1. In a clamping connector for making a clamped electrical connection between a rectangular connector pin and a wire type conductor, which clamping connector comprises an approximately Ushaped clamp having two free legs and a bottom and made of an elastic, electrically conductive strip material which can be slipped on to the connector pin and having its free legs bent inwardly in approximately semicircular form and contacting one of the lateral faces of the connector pin, with the bottom protion of the U-shaped clamp adjacent the opposite lateral face of the connector pin having an outward arch in the shape of a dome formed therein to form, with said opposite face, a channel to receive the conductor, after which said clamp may be subjected to a clamping force to affix the conductor in place, wherein the improvement comprises at least two window cutouts, one being made on each side of the domed portion, remote from the ends of the dome, formed by at least two circumferential cuts in the dome, the cuts extending to at least near the dome top, with the window cut out from the done bent downward and inwardly at the lower uncut edge of the window to form prongs protruding toward the interior of said channel and together with the dome-shaped arch at least partially clamping the conductor to prevent the conductor from turning aside or shifting during or after clamping.

2. A Clamping connector according to claim 1 wherein said prongs are curved and bent inward.

3. A Clamping connector according to claim 1 wherein the length of the prongs is chosen so that after clamping, the prong ends rest on the surface of the connector pin.

5. A clamping connector accorting to claim 1 wherein said prongs are angled off inwardly about the lower edge of the cutout and then outwardly about a line transverse to the longitudinal axis of the prong at approximately half the length of the prong.

7. A Clamping connector according to claim 5 wherein the length of the prongs is such that the prongs are wedged between the conductor and the surface of the conductor pin after clamping.

8. A Clamping connector according to claim 6 wherein the length of the prongs is such that the prongs are wedged between the conductor and the surface of the conductor pin after clamping.

9. A Clamping connector according to claim 8 wherein the length of the prong is selected so that the ends of the prongs on each side abut after clamping.