US3790924A

US3790924A - Relay-plug-in contact spring

Info

Publication number: US3790924A
Application number: US00250958A
Authority: US
Inventors: H Sauer
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 1971-05-21
Filing date: 1972-05-08
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05
Also published as: DE2125169B1; JPS5213306B1

Abstract

A spring plate is cut and bent along a center axis to form at one end resilient portions for receiving a contact pin and at the other end a generally trough-shaped tapering connector portion adapted to be inserted into a hole of a conductor plate and provided with a converging opening for receiving a connecting wire.

Description

Unite States Patent [1 1 Sauer [451 Feb. 5, W74

[ RELAY-PLUG-IN CONTACT SPRING [75] Inventor:

[73] Assignee: Matsushita Electric Works Ltd., Osaka, Japan [22] Filed: May 8, 1972 [21] Appl. No.: 250,958

Hans Sauer, Deisenhofen, Germany [30] Foreign Application Priority Data May 21,1971 Germany P 21 25 169.4

[52] US. Cl. 339/258 R, 339/276 A [51] Int. Cl H0lr 13/12 [58] Field of Search..... 339/17, 258, 259, 262, 275,

[56] References Cited UNITED STATES PATENTS 3,248,687 4/1966 lmmel 339/275 B 3,147,059 9/1964 Gluck 339/258 P FOREIGN PATENTS OR APPLICATIONS 1,465,686 4/1969 Germany 339/258 R OTHER PUBLICATIONS IBM Bulletin, Schick, Component Mounting and Wire Wrapping Contact, 10, 1962, Vol. 5, No. 5, p. 10.

Primary Examiner-Joseph l-i. McGlynn Attorney, Agent, or Firm-Edmund M. Jaskiewicz [57] ABSTRACT A spring plate is cut and bent along a center axis to form at one end resilient portions for receiving a contact pin and at the other end a generally troughshaped tapering connector portion adapted to be inserted into a hole of a conductor plate and provided with a converging opening for receiving a connecting wire.

5 Claims, 7 Drawing Figures 6 VII/AIWA 13 20 l L.

EUTQLLSZA PMENMB FEB 51914 III/AI'IIZ l RELAY-PLUG-IN CONTACT SPRING This invention relates to a relay plug-in contact spring of the type comprising resilient portions for receiving a Contact pin and a connector portion which may receive a connecting wire or may be inserted into a hole in a conductor plate and soldered to conductor bars disposed on the conductor plate.

Relay plug-in contact springs adapted to be inserted into conductor plates as well as for conventional wiring and soldering are obtained by providing the contact springs as used with conductor plates additionally with a soldering lug or a notch for receiving the connecting wire. However, since the hole provided in a conductor plate for a contact spring usually has a maximum diameter of about 0.05 inches there is the disadvantage that a soldering lug in the contact spring the width of which is limited by the hole cannot be made large enough to ensure free-of-trouble wiring. If a notch is provided, wiring becomes complicated because the end of the connecting wire must be bent to form a hook in order safely to engage the notch. Particularly with contact support members having contact springs arranged in several rows, thereare difficulties in the wiring of those contact springs which are closer to the support member.

In addition, there is a danger that the contact springs bend as a result of their cross-sections being weakened by the soldering lug.

For removing these deficiencies, it has been a common expedient to use for conventional wiring differently shaped connector portions of relay plug-in contact springs than for inserting into conductor plates. However, this expedient is highly expensive because two types of contact support members fitted with different contact springs must be available for each type of relay.

It is accordingly an object of the invention, to provide a relay plug-in contact spring of the kind mentioned above in which the said disadvantages are avoided, which is simple in structure and ensures troublefree handling.

SUMMARY OF THE INVENTION To this end, the connector portion of the plug-in contact spring according to the invention has .outer edges extending at an acute'angle with respect to the longitudinal axis of the plug-in contact spring such that the connector portion converges towards its free end, the connector portion having an opening overlying the longitudinal axis for receiving a connecting wire, being bent along the longitudinal axis to form a semicircular, oval or angular profile and terminating in at least one pointed tongue. By these features a plug-in contact spring'is obtained which may simply be manufactured as a die-cut and bent piece. The pointed tongue or tongues at the free end of the connector portion simplify the inserting of the contact spring into a hole provided in a conductor plate. A contact spring inserted into such hole is automatically retained by the elastic force of the connector portion. This is for instance advantageous in a case where a contact support member fitted with such contact springs is to be connected to conductor bars disposed on a conductor plate by dipsoldering because the contact support member is safely retained on the conductor plate without any additional mechanical fixture, merely by the contact springs. The

spring action of the connector portions also compensates for tolerances of the holes provided in the conductor plate.

The inserting of the contact spring into a hole of the conductor plate is furthermore simplified by the tapering free end of the connector portion. The diameter of the free end of the connector portion is smaller than that of the hole while the diameter of the connector portion at the end where the connector portion is connected to the resilient portions exceeds the diameter of the hole.

Besides of an elastic force which increases as the connector portion advances in the hole, there is the advantage that a relatively large opening can be provided in the connector portion for receiving a connecting wire so that even connecting wires of different diameters can be used without trouble. In addition, a connecting wire inserted in the opening is retained by the spring action of the webs formed between the opening and the outer edges of the connector portion.

The invention further provides a plug-in contact spring having a connector portion which, as a result of the semicircular, oval or angular bend, has a trough shaped profile providing increased stiffness. When a contact support member fitted with plug-in contact springs according to the invention 'is used with conductor plates the increased stiffness yields the advantage that it is nearly impossible for the contact springs to bend due to excessive tolerances of the holes in the conductor plate or for other reasons. Similarly, when used for conventional wiring, the high stiffness of the connector portions of the contact springs ensure that stresses which may be exerted by the connecting wires cannot easily deform the connector portions, thereby avoiding for instance short circuits with adjacent contact springs. I

In a preferred embodiment of the invention, one pointed tongue is provided on each side of the longitudinal axis at the free end of the tapering connector portion.

According to another preferred embodiment, each pointed tongue is bent off such that the trough-shaped profile of the connector portion is substantially closed at the free end of the connector portion thereby further simplifying the inserting of a plug-in contact spring into a hole of a conductor plate. When wires are connected to the connector portions, there is the advantage that the required solder is retained by the closure of the trough-shaped profile like in a pocket with the result that good contact between the connector portion and the wire is obtained.

In a further embodiment of the invention, the opening in the connector portion is shaped such that the periphery of the opening in the area of the connector portion extends parallel to these edges. This provides particularly useful spring characteristics with respect to the inserting of the plug-in contact spring into a hole provided in a conductor plate as well as with respect to the elastic force which retains a connecting wire in the opening. In addition, the opening provided for the connecting wire converges towards the free end of the connector portion with the advantage that a connecting wire inserted in the opening is positively drawn by any occurring stress into the steadily narrowing zone of the opening, thus being retained more and more firmly.

According to another embodiment of the invention, a shoulder is provided on each side of the longitudinal springs are forced into the recesses until the shoulders engage abutments provided in the support member and are thus locked by the elastic force of their connector portions. Each plug-in contact spring is thus fixed in a predetermined position without requiring additional means.

The foregoing objects, features and advantages of the invention will become apparent from the following description of a preferred embodiment in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. outline o f a non-bent plug-in contact spring according to the invention;

FIG. 2 is a sideview of the plug-in contact spring of FIG. 1 with bends provided in the area of the resilient portion and the connector portions;

FIG. 3 is a sideview of a finished bent plug-in contact spring according to the invention;

FIG. 4 is a longitudinal section along the lines IV IV of FIG. 3;

FIG. 5 is a cross-section along the lines V V of FIG. 3; and

FIGS. 6 and 7 are cross-sections through a connector portion of a plug-in contact spring bent to oval and, respectively, semicircular form.

V 7 DETAILED DESCRIPTION OF EMBODIMENT A plug-in contact spring according to the invention the outline of which is shown in FIG. 1 is punched from spring sheet metal and consists of a connector portion 1 and two contact portions 2, 3. A T-shaped slot 9 divides the plug-in contact spring into two halves which are symmetrical about a longitudinal axis 16 of the spring and are each subdivided by

notches

10, 11 into two

resilient portions

2a, 2b and 3a, 3b. These

resilient portions

20, 2b and 3a, 3b form a pair of double contacts for a contact pin such as of a relay. The

outer edges

17, 18 of the connector portion I extend at an acute angle with respect to the longitudinal axis 16 so that the connector portion 1 converges towards its free end.

The connector portion 1 is further provided with an opening 4 overlying the longitudinal axis 16, the edge 19 of the opening 4 in the area of the

edges

17, 18 extending parallel to these

edges

17, 18; this provides particularly useful spring characteristics with respect to a connecting wire 14 to be received in the opening 4 as well as with respect to a hole 20 provided in a conductor plate 13 into which the connector portion 1 is inserted. The free end of the connector portion 1 is further provided with a

pointed tongue

5, 6 on both sides of the longitudinal axis 16. v

The connector portion 1 is also provided at itsend adjacent the

resilient portions

2a, 2b and 3a, 3b on each side of the longitudinal axis 16 with a

shoulder

7, 8 extending perpendicularly of the longitudinal axis 16 for retaining the plug-in contact spring in a contact support member 21. When the contact spring is inserted into an opening 22 in the contact support member 21 the

shoulders

7, 8 are locked in such opening 22, as shown in FIGS. 3 and 4, and the contact spring is prevented from falling out of the support member.

FIG. 2 represents a longitudinal section of the plug-in contact spring shown in FIG. 1. In contrast to FIG. 1, however, the contact spring as shown in FIG. 2 has been shaped in a first bending step. Particularly, the

pointed tongues

5, 6 have been bent in a zone B and the

resilient portions

2a, 2b, 3a and 3b in zones C. For greater clarity of the drawing, FIG. 2 shows only the tongue 5 and the resilient portion 2a.

The remaining Figures display the plug-in contact spring after finishing in a second bending step. As shown in FIG. 5, by this second bending, an angular profile is formed in a zone D of the connector portion 1 and the contact portions 2, 3 are bent in zones E so as to face each other. As can be seen in FIGS. 3 and 4, a spatially pointed element is created by the bent trough-shaped profile of the connector portion 1 in connection with the

tongues

5, 6 which have been bent before. Such an element is easily inserted into the hole 20 of the conductor plate 13.

Also, the inserting of a connecting wire 14 into the opening 4 is simplified by the form of the connector portion 1 which converges toward its free end and by the bend in the zone D. As shown in FIG. 3, the connecting wire 14 is resiliently retained in the opening 4 by an elastic force which is the greater the further the wire is moved downwardly in the converging opening 4. The connecting wire 14 may thus firmly be pinched in the opening 4 prior to soldering so as to provide a good electrical contact between the connector portion 1 and the connecting wire 14. Simultaneously, provision is made against malfunctions which may be caused by cold-iron soldered joints. In addition, soldering of the connection wire 14 is particularly easy because the trough-shaped profile of the connector portion 1 is substantially closed off by the

bent tongues

5,6 so as to form a pocket for retaining the solder. FIGS. 3 and 4 also show the double contact formed by the

resilient portions

2a, 2b, 3a, 3b for receiving a contact pin.

By the bends in the zones C (FIG. 2) of the resilient portions, an opening is formed which facilitates the inserting of the contact pin.

As mentioned above, the connector portion 1 is formed with a trough-shaped profile by bending the portion 1 along the longitudinal axis 16. As far as stability to loads exerted in any direction is concerned, it does not matter whether the profile is rectangular (FIG. 5), oval (FIG. 6) or semicircular (FIG. 7).

I claim: 7

iI A relay plug-in contact spring comprising at least two pairs of resilient portions for receiving a contact pin and a connector portion for receiving a connecting wire or for being inserted into a hole of a conductor plate and soldered to conducting bars disposed on such conductor plate, said contact spring having the outer edges of said connector portion extending at an acute angle with respect to the longitudinal axis of said plug-in contact spring so as to converge towards the free end of said connector portion, an opening in the lower end of said connector portion overlying said longitudinal axis for receiving said connecting wire, said connector portion being bent along said longitudinal axis 1, wherein said opening is shaped such that the edges of said opening extend parallel to the edges of said connector portion.

5. A relay plug-in contact spring according to claim 1 wherein one shoulder is provided on each side of said longitudinal axis at the end of said connector portion adjacent said resilient portions, said shoulders extending perpendicularly of said longitudinal axis for retaining the plug-in contact spring in a contact support member.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 790 924 Dated February 5,1974

la ighvenor-(s) Hails Sauer V It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

(73) Assignee: Matsushita Electric Works Ltd.

Osaka, Japan and Hans Sauer I Deisenhofen, Germany Signed and sealed this 30th day of July 197A.-

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN' Attesting Officer Commissioner of Patents

Claims

1. A relay plug-in contact spring comprising two pairs of resilient portions for receiving a contact pin and a connector portion for receiving a connecting wire or for being inserted into a hole of a conductor plate and soldered to conducting bars disposed on such conductor plate, said contact spring having the outer edges of said connector portion extending at an acute angle with respect to the longitudinal axis of said plug-in contact spring so as to converge towards the free end of said connector portion, an opening in said connector portion overlying said longitudinal axis and adjacent said free end for receiving said connecting wire, said connector portion being bent along said longitudinal axis at its free end to form a semicircular, oval, trough-shaped profile, and terminating in at least one pointed tongue.

2. A relay plug-in contact spring according to claim 1, wherein said one pointed tongue is provided on each side of said longitudinal axis at the free end of said converging connector portion.

3. A relay plug-in contact spring according to claim 1, wherein each said pointed tongue is bent so as substantially to close off the trough-shaped profile of said connector portion at the free end thereof.

4. A relay plug-in contact spring according to claim 1, wherein said opening is shaped such that the edges of said opening extend parallel to the edges of said connector portion.