US3219781A

US3219781A - Electromagnetic relay with sliding leaf spring movable contacts

Info

Publication number: US3219781A
Application number: US286634A
Authority: US
Inventors: Eugene M Miller; Jerry O Kelley
Original assignee: RADON CORP
Current assignee: RADON CORP
Priority date: 1963-06-10
Filing date: 1963-06-10
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23

Description

Nov. 23, 1965 E. M. MILLER ETAL 3,219,781

ELECTROMAGNETIC RELAY WITH SLIDING LEAF SPRING MOVABLE CONTACTS Filed June 10, 1963 p 19 n 1 195 2 B x D 1 /9 0 I a t 7 llllllllllll l'l 5 5/ INVENTOR. (XE-RR) 0. /f 1.15) 4 50651105 A4. M14 L ER AT K1 1 United States Patent 3,219,781 ELECTROMAGNETIC RELAY WITH SLIDING LEAF SPRING MOVABLE CONTACTS Eugene M. Miller, Crystal Lake, 111., and Jerry O. Kelley,

Lake Ozark, Mo assignors, by direct and mesne assignments, to Radon Corporation, a corporation of Illinois, and Donald J. Moloney & Associates, Inc., a corporation of Illinois Filed June 10, 1963, Ser. No. 286,634 Claims. (Cl. 200-104) The principal object of the improvements disclosed is the provision of a contact system useful generally for switching purposes but especially adapted to use in an electromagnetic relay of the solenoid type in which the driving or actuating means is a member, such as a solenoid plunger, which moves linearly.

The contact system is characterized chiefly in the fact that it includes a set of movable contacts in the form of elongated, bowed fingers of relatively great flexibility which are grouped about the linearly movable driving or actuating member so that their principal motion is in the general direction of displacement paralleling the axis of displacement of the driving member, but the contacting ends of such fingers bear against a panel carrying stationary contacts arranged circumambiently and radially about such axis and the fingers flex so as to glide over the panel in a changed direction which is radial, and in so doing to wipe over the stationary contacts in advancing or retreating from one concentric ring of such contacts to another.

The disclosed contact system has the advantage that it is especially effective for use with the printed circuit type of contact chemically, electrolytically, or mechanically laid down in more or less flush relation with the panel carrying the stationary array of contacts, by reason of which a large number of contacts can be employed at small expense in a small space and easily wired.

The novel construction makes use of the relatively more etlicient solenoid electromagnet and can be made in large or miniature embodiments, and both the movable and stationary contact components may be pre-wired before assembly with the electromagnetic drive or actuating means.

Additional aspects of novelty and utility pertain to details of the construction and operation of the embodimerit described for purposes of illustration hereafter in view of the annexed drawing in which:

FIG. 1 is a perspective view of a relay embodying the new contact arrangement;

FIG. 2 is a vertical section looking in the direction of lines 22 of FIG. 1;

FIG. 3 is an exploded perspective of the moving contact assembly;

FIG. 4 is a cross-sectional deatil of the contact retaining cap;

FIG. 5 is a fragmentary cross-sectional detail of a modified contact panel structure;

FIG. 6 is a view similar to FIG. 5 with parts differently positioned.

While the novel contact means may be used with any kind of actuator arranged to impart linear reciprocatory motion to the moving contact means, the improvements have a particularly important use in conjunction with a soTenoid type relay such as depicted in FIGS. 1 and 2, and which in the illustrative form shown comprises a U-shaped ferromagnetic frame piece 10 having a solenoid winding 11 set in the yoke thereof.

Within the bore of the solenoid is the usual magnetically-attractable plunger 12 normally elevated by a spring 13 and attracted inwardly of the bore on energization of the winding with the heel of the plunger striking a small stop plug '14 (FIG. 2).

Secured by suitable means, such as screws 16, is a contact panel 18 of insulating material carrying an array of stationary contacts exposed on the upper face thereof, such contacts being preferably of the printed-circuit variety embedded in the panel with only their uppermost surface areas exposed in the plane of the upper face of the panel.

The stationary contacts are arranged concentrically of a center in the panel which coincides with the center of the bore of the solenoid and the axis of the plunger working therein; and said contacts each include portions lying principally in radial paths relative to said center and axis. Thus, in FIG. 1, contacts 1'9 lie in an inner ring and have contact areas elongated along a radius Z with an offset connection portion 19A continuing outwardly toward the edge of the panel to terminate in soldering eyelets 193.

The contacts 20 which lie in the next outer ring also lie along the aforesaid radius Z but continue directly to the panel edge into their corresponding connecting terminals or soldering eyelets 20B. Thus, all circuit connections to the stationary contacts may be made to the terminal eyelets around the periphery of the contact panel, as will be apparent from the fragmentary wire connections 23 shown, which illustrates pre-wiring.

The movable contact means is carried on the upper exposed end regions of the solenoid plunger which is long enough to project through the central opening 18A of the contact panel a substantial distance above the upper face thereof.

An insulated contact-carrying means is mounted on the upper end of the plunger and preferably comprises the parts particularly seen in FIG. 3, including a molded seat member 25 of cylindrical configuration having spaced about its outer periphery a plurality of contact-seating grooves or channels 26 defined between ribs 27 spaced apart to receive one of the elongated spring contact fingers 30 in the bottom thereof.

Each contact spring 30 has an upper terminal end portion 31 bent outwardly to project beyond the periphery of the cylindrical seat so as to be exposed for soldered connection with a conductor or jumper. The contact fingers are bowed in a direction outwardly of the plunger, and their lower free ends are given a form to provide contact wipers 32 adapted to glide along the surface of the stationary contact panel.

The contact seating member 25 is molded with a central bore having a slight taper to fit closely with a corresponding seating taper on the upper end of the solenoid plunger, and the several spring contact fingers are secured in their respective seats by a molded annular cap 35 having a plurality of grooves 36 and ribs 37 about its inner periphery interfitting with the ribs and grooves on the seat, whereby the contact fingers are locked into their seating grooves or channels with their respective terminal ends 31 projecting from beneath the cap, as seen in FIGS. 1 and 2. The contact assembly is fixed in position by means of a cap washer 37 and a screw 38 threading into the end of the plunger.

Means for preventing the contact assembly from rotating about the axis of the plunger comprises (FIGS. 1 and 2) a keyway 15 in the plunger into which a small tab 21 projects, tab 21 being part of the contact panel.

It will be apparent that a variety of switching connections may be made to the contact array shown, one of the simplest being the cross-connection of adjacent contact fingers by jumpers such as that shown at 39, whereby the two inner contacts 40 will be cross-connected when the plunger is elevated, and the two outer contacts 41 will be cross-connected when the plunger is pulled in and the corresponding'wiper fingers lodged thereon. Or, in another switching arrangement, flexible conductors such as that at 44 may be connected by soldering to the desired contact fingers.

In cases where the current to be carried by the contact system is high enough to cause objectionable arcing and carbonization or like resultant deposits between the stationary contacts along each radial path, the arrangement shown in FIG. 5 may be employed to cause the spring contact fingers to provide another motion component which will move the contacts upwardly away from their stationary contacts concurrently with the radial advance of the wiper as it leaves one contact for engagement with another. In this arrangement, a lifting means in the preferred form of a small protuberance 46 is molded into the contact panel 18X between successive radiallyaligned contacts in such size and position as to cause the advancing contact portion of the finger 32X to rise upwardly from the stationary contact areas and descend downwardly onto the next such area, or conversely in the reverse movements of the wipers, e.g. FIG. 5 from 19 to 20 or vice versa.

While many contact arrangements have been employed in the past in conjunction with solenoids having plungers adapted to move radially projecting contacts, no simple system is known which succeeds in converting the linear displacement of the moving contact into a laterally, radial gliding movement of appreciable magnitude in which the contacting action is either wholly a wiping action or a compound motion both radial and tactile, as in the case of the lifting contact motion of FIG. 5.

The improvements are not confined to the foregoing construction described by way of illustration, but may take other forms within the scope of the invention as defined by the appended claims. For example, the array of wiper fingers may be held stationary and the contact panel made to move relative thereto. Likewise, a single solenoid may be employed to drive more than one array of movable contact fingers relative to an appertaining panel of stationary contacts.

We claim:

1. In a relay, a contact panel having at least two concentrically arranged rings of contacts adapted to be connected and disconnected from associated circuit connections; a plunger movable linearly and centrally of said rings of contacts along the axis of concentricity thereof; electromagnetic means for reciprocating said plunger, and contact means carried by said plunger circumambiently thereof and comprising flexible spring fingers each having a free end portion projecting toward the plane of said panel at an angle such that on movement of the plunger a predetermined amount in a direction to displace said contacting free end portion toward the panel, said contacting portions will glide along the surface of the panel in a direction generally radially outward from the plunger for wiping contact engagement with contact means in said rings.

2. Contact means for use in switching devices, relays, and the like, and comprising a flat insulating panel, a drive member movable along an axis which is substantially at right angles to the plane of the panel, means for reciprocating said drive member between predetermined working limits relative to the panel, elongated spring contact fingers each attached at one upper end portion remote from said panel to an insulating member carried by said drive member and each at spaced positions around said drive member, each finger having a portion projecting toward the panel in the general direction of movement of the drive member, and each said finger portion terminating in a contact portion angularly disposed to bear against said panel and glide along the latter in a general direction radially outward from said axis responsive to a predetermined amount of movement of the drive member in the direction toward the panel; and contact means carried on said panel at positions about said axis and lying in the path of radial gliding movement of one of said fingers to be engaged and disengaged by the latter responsive to reciprocatory movement of the drive member.

3. In a contact system, a linearly reciprocable actuating member, an array of elongated spring finger contacts arranged about the axis of movement of said actuating member and connected thereto for reciprocatory movement therewith, said finger contacts each having a portion extending generally in the direction of such movement and converging into another portion directed outwardly away from said axis and terminating in a free contacting end portion including a gliding surface, together with means providing an insulating gliding surface lying in a plane at right angles to said axis in confrontation with said free contacting end portions and engaged thereby and serving to deflect said end portions on advance of the same in the direction against said surface responsive to operation of said actuating member accordingly, whereby the contact fingers are flexed sufficiently to cause said contacting end portions thereof to glide radially away from said axis and wipe along radial paths on said surface; and stationary contact means arranged on said surface in the path of radial gliding movement of said contacting end portions for engagement and disengagement by the latter responsive to a predetermined amount of reciprocatory displacement of said actuating member.

4. In a contact system according to claim 3, the further provision that said stationary contact means includes at least two stationary contact areas spaced apart along a radius to said axis and lying in the path of gliding travel of an appertaining one of said contact end portions so as to be individually engaged and disengaged in succession thereby, and said areas are separated by a non-conductive protuberance rising above said surface in a manner to cause said free contacting end portion of the appertaining contact finger to be displaced in a sense laterally away from an adjacent one of said areas while gliding toward or away from the other of said areas.

5. A relay comprising a substantially linearly-reciprocable operating member; stationary contact means arranged in a plane normal to the axis of reciprocation of said operating member and lying along a path which is disposed radially of said axis in said plane; movable contact means including at least one elongated spring contact finger and means connecting one end region thereof for movement with said operating member so that the major lengthwise portion of said finger moves back and forth in approximate parallelism with said axis and operating member toward and away from said plane, said finger having an opposite end portion biased outwardly in an approximately radial sense from said axis for engagement with said contact means to glide thereon radially of said axis responsive to linear reciprocation of said operating member; and electromagnetic means for reciprocating said operating member.

References Cited by the Examiner UNITED STATES PATENTS 1,305,970 6/1919 Kennedy 200104 X 2,162,528 6/1939 Curtiss 20016 BERNARD A. GILHEANY, Primary Examiner.