US2767356A - Multiple armature marginal relay - Google Patents

Description

Oct. 16, 1956 D. OLSSON 2,767,356

MULTIPLE ARMA'EURE MARGINAL RELAY Filed April 3, 1952 l5 7 .9 l3 27 3 8 Ln 4,

9 5 3/ a /4 l5 l2 7 United States Patent Ofiice 2,767,356 Patented Oct. 16, 1956 2,7 67,358 M LTIPLE ARMATURE MARGINAL RELAY Gunnar Daniel Olsson, Stockholm, Sweden Application April 3, 1952, Serial No. 280,341 2 Claims. (Cl. 317-189) The present invention relates to electromagnetic relays and has as its object to provide an electromagnetic relay which is capable of performing a large number of contact functions though having small dimensions.

Another object of the invention is to provide an electromagnetic relay, in which difterent contact functions may be obtained in a predetermined time succession and in which one or more contact functions are selectively operable.

Still another object of the invention is to provide adjusting means for adjusting the required contact pressures or initial load of the armatures of the relay.

The relay according to the invention is particularly useful as a multi-step relay, in which different contact functions are effected stepwise on [a continuous or stepwise increase of the energizing current force, or as a current selective combination relay, in which the supply of a predetermined energizing current force directly effects a predetermined combination of contact functions.

According to a feature of the invention the core of the relay is at its ends provided with transversally projecting end pieces of magnetic material, two or more armatures extending along the length of the core and forming external flux paths between the said end pieces, which paths are disposed in different radial directions with relation to the longitudinal axis of the core.

According to another feature of the invention the armatures or the flux paths formed by them show different reluctance values and/or the armatures have diilerent initial loads or restoring forces in order to effect successive or selective operation of the different armatures.

Other objects and features of the invent-ion will appear from the description of the annexed drawing, in which:

Fig. 1 shows a relay according to the invention in side elevation.

Fig. 2 shows the same relay in end view.

Fig. 3 shows an armature of the relay in plan view.

Fig. 4 shows the same armature in side view.

Fig. 5 shows a holding spring, one being provided for each armature, in plan view.

Fig. 6 shows the same spring in side view.

Fig. 7 illustrates a possible modification of the spring shown in Figs. 5 and 6.

Fig. 8 shows a contact member of view.

Fig. 9 shows the same contact member in side view.

Fig. 10 shows the same contact member in end view.

Fig. 11 shows a connecting member of the relay in plan view, and

Fig. 12 shows the same connecting member in side view.

Reverting to Figs. 1 and 2 the magnetic core of the relay with its winding coil is designated 1. The core is at each end connected with an end piece 2 and 3 respectively having in the shown embodiment quadratic cross-section (see Fig. 2). The relay is provided with four armatures, three of which, 4, 5 and 6, are visible in the drawing.

the relay in plan As appears most clearly from Figs. 3 and 4, each armature comprises a strip 7 of magnetic material having a thin strip 8 of insulating material riveted by means of a sheet metal piece 9 with fixing lugs 10 to that side of the magnetic strip, which faces the core :of the relay. Furthermore, the armature is provided with contacts 11 and possibly also with studs 12 of insulating material for operatin contact springs or members which must not be electrically connected with the armature. For reasons which will be stated below each armature may be provided with a bore 13, and the bores of the different armatures may differ in size or number. At the end opposite to the contact end each armature is provided with a tre'aded pin 14 and two projections 15.

The larmatures 4, 5 and 6 are pivotally mounted on end piece 2 by means of holding springs 16, 17 and 18. These springs have the shape shown in Figs. 5 and 6. Each spring thus comprises 'a soldering lug for the electrical connection of the armature, a fixing portion 20 having fixing holes 21, a stifiened intermediate portion 22 and an end portion 23 for the engagement with the armature. In the end portion 23 there is a slot 24 for receiving the also two holes 25 in which the projections 15 fit. As appears from Fig. 6 each spring is provided with bendings at a, b and 0, so that the main extension of the spring forms .an are, which is to some extent straightened out on assemblage and represents a pretensioning of the spring. Furthermore portion 23 is given a particular pre-bending downwards in order to warrant the possibility :of adjusting the contact pressure as will appear more closely from the following.

The holding springs 16, 17 and 18 are each mounted on the top :of a contact assembly 26, 27 and 28 respectively. Each of these assemblies comprises 'a number of contact members 29, shown separately in Figs. 8-10, terminal strips 30, shown in Figs. 11 and 12, for the electrical connection of the contact members 29, and insulating spacers, possibly also additional terminals for the winding coil, which parts are stacked together and insulatedly attached to a supporting piece 31 by means of screws 32. This way of assembling contact members and terminals in mutually insulated relation is well known in the art and is the method commonly used in telephone relays. The supporting piece 31 preferably forms an extension of the end piece 3 and may be integral therewith.

As appears from Figs. 8-10 each contact member 29 consists of a relatively thin spring member having a fixing portion 33 with fixing holes 34, an intermediate, narrower portion 35 and an expanded contact portion 36. The portions 35 and 36 are divided into two halves through a centrally disposed slot 37 for providing a twin contact arrangement. On the two halves of contact the terminal strip in mounted position. The halves of the contact portion 36 of contact member 29, however, are at their outer ends as reckoned from the slot 37 bent a little in a direction opposite to the main pre-bending (see Fig. 10), so that the contact pieces 38 in mounted position of the contact member are somewhat resilient with relation to the associate terminal strip 30, which will eliminate or materially reduce the tendency of contact bouncing. Since the lateral bending of the contact portion 36 of contact member 29 is straightened out on the contact closure there will also be a friction damping. In Fig. 1 the armature 6 forms together with the contact members 29 of spring assembly 28 a change-over contact. It is thus required that the contacts of the armature 6 abut with predetermined pressure against the contacts of the lower contact member 29 in non-operated position of the armature. This is effected by the aid of the supporting spring 18.

On mounting the relay the projections 15 (Figs. 3 and 4) of the armature are inserted into the holes 25 (Fig. 5) of the holding spring, and a nut 39 is screwed onto the threaded pin 14. The projections thus will keep the armature in the desired relative positions with relation to the holding spring so that the armature will obtain a fixed longitudinal direction and a fixed position in this direction. This result may also be obtained by providing instead the portion 23 of the holding spring with bent-down lugs embracing the armature. Such a modification is outlined in Fig. 7 in which the lugs are designated 40 and 41. Due to the pre-tension of the holding spring 18 effected by the pre-bending at a in Fig. 6 the armature is at its pivoted end pressed against the end piece 2, and due to the pre-tensioning of portion 23 at c in Fig. 6 this portion tends to form a small angle to the outer surface of the armature 6. As will be understood, the contact pressure against the lower contact member 29 of spring assembly 28 may be easily adjusted by turning the nut 39, the highest pressure being obtained if the nut is screwed on completely. After the desired contact pressure has been obtained the nut is locked in its position by means of locking lacquer or any other locking means. Of course the pin 14 and nut 39 may be replaced by a screw being screwable in a threaded hole in the armature.

In the contact assembly 26 the arrangement is somewhat modified, so that instead a break contact separated from the armature is obtained at the top and a make contact is formed by the armature at the bottom of the assembly. To this end a special contact spring is mounted on the upper side of the armature 4 and pre-bent so as to press against insulating studs 15 on the armature. Of course, the pre-tension of spring 42 is much smaller than the upwardpressure of the armature, so that the main portion of the last-mentioned pressure acts as contact pressure in the break contact. An insulating member 43 is provided at the right hand end of armature 4 for engagement with the left hand free end portion of spring 42.

As will be understood the insulating strips 8 serve to separate electrically the different armatures and also to form spacing members for effecting the required magnetic air gaps in operated position of the armatures.

The holes 13 impart to the armatures different magnetic resistances. It will thus be appreciated that if the initial loads and the air gaps of the different armatures in non-operated position are equal and the relay is supplied with a successive increasing energizing current the armatures will be operated in order, first the one having the smallest and last the one having the largest hole 13. In this way it is possible to have one armature operated at one current force, two armatures operated at another, higher current force etc. supplied to the winding coil. Due to the fact that each operated armature forms a magnetic shunt path for thearmature or armatures not yet operated the margins between the required energizing current values of the different armatures will materially increase, which warrants a safe selective operation. By the aforementioned efiect the differences between the operation times of the different armatures are also increased in the case the relay is supplied with a current sufficiently large to cause two or more armatures to become operated. This may be utilized for efiecting a predetermined time succession of the contact functions performed by the difierent armatures, e. g. for providing a continuous change-over contact function, a break or make contact function which is early in relation to another break or make contact function etc.

It is evident that the selective or successive operation of the armatures described above also or instead may be effected by giving the different armatures different initial loads or restoring forces (by means of the holding spring 16-48) or by arranging difierent air gaps between the respective armatures and either or both of the end pieces 2, 3. There are also many other ways of imparting to the different magnetic circuits extending through the respective armatures different reluctance values, which are known by all skilled in the art.

I claim:

1. An electromagnetic relay comprising a core having a winding thereon, end pole pieces connected to said core, at least two magnetic armatures forming external flux paths between said end pole pieces disposed in different radial directions with relation to the longitudinal axis of the core, pivoting means for pivotally supporting said armatures in relation to said core, said armatures being of substantially the same general size and configuration and at least one of them having a portion thereof cut away at a place intermediate the portions adjacent to the end pole pieces for altering the magnetic reluctance of said armature as compared to the reluctance of at least one other of said armatures, whereby said armatures will be attracted successively by said core in the inverse order of their respective reluctances responsive to increasing magnetization of said core accompanying an increasing currentflowing in said winding.

2. An electromagnetic relay as claimed in claim 1, in which said cut out portion is a central aperture.

References Cited in the file of this patent UNITED STATES PATENTS 133,968 Davis Dec. 17, 1872 535,511 Sperry Mar. 12, 1895 782,731 Eastwood Feb. 14, 1905 1,182,894 Chesler May 16, 1916 1,440,551 Patterson Jan. 2, 1923 1,487,694 Brockway Mar. 18, 1924 1,534,753 Watson Apr. 21, 1925 1,800,256 Keller Apr. 14, 1931 1,863,836 Derby et al. June 21, 1932 2,438,745 FOX Mar. 30, 1948 FOREIGN PATENTS 490,906 Germany Feb. 1, 1930 769,391 France Apr. 24, 1934

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