US2985735A

US2985735A - Electric relays

Info

Publication number: US2985735A
Application number: US812060A
Authority: US
Inventors: Bede Bela
Original assignee: NEW ELECTRONIC PRODUCTS Ltd
Current assignee: NEW ELECTRONIC PRODUCTS Ltd
Priority date: 1959-01-19
Filing date: 1959-05-08
Publication date: 1961-05-23
Anticipated expiration: 1978-05-23

Description

May 23, 1961 B. BVEDE ELECTRIC RELAYS Filed May 8, 1959 l .l il wf :M /03 ya? Patented May 23, 1961 ELECTRIC RELAYS Bela Bede, London, England, assignor to New Electronic Products Limited, a company of Great Britain Filed May 8, 1959, Ser. No. 812,060

AClaims priority, application Great Britain Jan. 19, 1959 9 Claims. (Cl. ZOU- 1103) This invention relates to electric relays.

The main object of the invention is to provide a relay which is so balanced that no acceleration or spin imposed upon it will cause it to operate.

A second object is the provision of a relay having a number of independent contacts which are separately adjustable.

With the above-stated main object in mind, the invention provides a relay comprising a base, a pair of similar armatures mounted upon the base for pivotal movement with respect thereto about parallel axes, a core and coil also mounted on the base, the core presenting poles to the armature such that energization of the coil causes them to pivot in opposite angular directions against the action of a bias, means interconnecting the armatures such that the movement of one is always equal and opposite to that of the other, and at least one contact actuated on movement of the armatures.

The armature interconnecting means preferably comprises first and second rigid arms extending one from one armature and one from the other in a plane perpendicular to that in which the armature pivot axes lie, one arm having a tubular end portion and the other mounting near its end a ball which fits snugly within the interior of said tubular end portion and lies substantially equidistantly from both armature pivot axes.

A furtherl important feature of the relay lies in the means for actuating the contact or contacts, which preferably comprise a pin (conveniently an adjustable screw) extending from one (or from each) armature and a micro switch located in the path of the movement of the end of the (or each) pin which takes place upon movement of the armatures. There is no theoretical limit to the number of contacts which the relay can actuate; each pin may be adjusted separately without the adjustment having any effect on the other contacts; moreover, by reason of the micro switch action, the contact operation will be reasonably fast. The contact actuating means just described may be used in relays other than such as specified in the fourth paragraph hereof.

Yet another important feature of the relay according to the invention concerns the bias applied to the armatures: preferably this bias is provided by a permanent magnet, which conveniently can be made to act upon a part of each armature on the opposite side of its axis to such part es is aiiected by the corresponding pole on the core of the coil. This bias avoids the use of springs, which under certain conditions of vibration may resonate and render the relay unreliable.

One form of relay embodying the invention and a modication thereof, willL now be described by way of example with reference to the accompanying diagrammatic drawings, in which:

Figure l is a diagrammatic perspective view of the relay;

Figure 2 is a perspective diagram illustrative of the armature interconnecting means, and

Figure 3 is a perspective view of the modified relay.

Referring to Figures l and 2 of the drawings, the relay comprises a rectangular plate-like base 1 of soft magnetic material. At each end of the base a pair of lugs 2 is secured by screws to one side of the base and extends beyond the end of the base in the general plane thereof. Generally rectangular plate-like armatures 3, 4 are mounted at the ends of the base, one between each pair of lugs 2, by means of pins 5 carried by the lugs and defining pivot axes for the armatures which are parallel to each other and lie in the general plane of the base: each pivot axis passes through the centre of gravity of the corresponding armature. A wire spring 6 is mounted on each pair of lugs, so as to bias the upper end of the corresponding armature towards the base.

A plate-like core 8 of soft magnetic material having the same general dimensions as the base 1 is mounted below and parallel to the base on non-magnetic posts 9. The core 8 carries a coil 10 and provides poles at its ends 11, 12. Energization of the coil 10 causes the armatures 3, 4 to move in opposite angular directions to bring their lower ends into contact with the poles 11, 12, the magnetic circuit running through the base 1, core 8 and the lower parts of the armatures 3, 4.

Each armature 3, 4 has a lateral extension, 15, 16 carrying a rigid arm 17, 18 perpendicular to the armature. The arm 17 is tubular, at least at its free end portion, and is slit at 19. The arm 18 has a strip-like extension 20 with a hole 21 near its free end which locates a ball 22 (preferably of sapphire for lightness and strength) fitting snugly within the arm 17 and lying equidistantly from the armatures.

The arms 17, 18 interconnect the armatures 3, 4 so that movement of one is always equal and opposite to that of the other. On movement of the armatures, the ball 22 moves in the arm 17 and the extension 2) moves freely in the slit 19.

Each armature 3, 4 has near its upper edge a tapped hole perpendicular to its general plane which adjustably receives a screw 25, 26. The inner ends of the screws 25, 26 co-operate respectively with micro-switches 27, Z3 mounted on the base 1, and are in continuous Contact therewith. The micro switches 27, 28 are of conventional construction and comprise a light springmetal contact arm 29 mounted at one end 30 and with its other end making contact with one or other of two

contact posts

31, 32. In the un-energized condition of the coil 10 the micro switch arms 29 contact the posts 31: when upon energization of coil 10 the screws 25, 26 move apart, the arms 29 contact the posts 32 due to bias in the arms. This latter bias is, of course, insutiicient to overcome that provided by the wire springs 6.

It will be appreciated that the relay is balanced against all accelerations and spin, that the contacts are independently adjustable, and that within reason any number may be provided as conditions of use may dictate.

In the relay of Figures l and 2 the ybias on the armatures is provided by wire springs. Now under certain conditions of vibration these springs may resonate and fail to provide the required bias, so rendering the relay unreliable. The modified form of relay shown in Figure 3 is designed to avoid this drawback: apart from the bias on the armatures it is generally similar to that of Figures l and 2, corresponding parts being designated by similar reference numerals distinguished by a prime. However compared with the relay of Figures l and 2 that of Figure 3 is inverted and differs also in being mounted on a base plate of insulating material, the base 1' being secured thereto by stout brass posts (not shown). Other minor differences concern the lugs 5 which are here integral with the base 1', and the micro switch 27 which is here mounted on the base plate 100 on the outside of the armature 3 which actuates it.

A pair of

similar pole bars

101, 102 of soft magnetic material are mounted on the base 1 in spaced relation thereto and on the side opposite the coil by means ol' brass posts (not shown). Each pole-bar 101, I102 presents'onc edge towards one of the armatures 3', 4 the relative positions of armature and `pole bar being the same at each armature. A permanent magnet 103 is mounted between the pole bars 101, `102 by means of a brass clamping plate 104: each end of the magnet rests on one of the pole bars and the clamping plate, which extends beyond the magnet, is held to the pole bars by screws 105.

The magnetic circuit due to the coil 10 passes through the core S therefor, the upperhalf of each of the armatures 3', 4 and the base 1. The magnetic circuit due to the permanent magnet 103 passes through the pole bars 1011, 102 the lower half of each of the armatures 3 and d and the base 1'. The magnet l03'sets up a bias on each armature 3', 4 tending to move it in a direction opposite to that in which it is moved on energization of the coil 10', the bias onthe two armatures lbeing equal and opposite due to the symmetrical arrangement of armatures and

pole bars

101, 102. The bias due to the magnet 103 is suicient to hold the upper ends of the armatures 3', 4 away from the core 8 when the coil 10 is unenergized.

Energization of the coil by a current of. the magnitude to which the relay is desired to respond moves the upper ends of the armatures 3', 4 towards the core 8 against the bias due to the magnet 103.

It will be understood that the permanent magnet described dispenses with the need for springs, and that there is nothing in the relay which can resonate no matter how it is vibrated.

I claim:

1. An electric relay comprising a base, a pair of similar armatures mounted upon the base for pivotal movement with respect thereto about parallel axes, a core and a coil also mounted on the base, the core presenting poles to the armature such that energization of the coil causes them to pivot in opposite angular directions against the action of a bias, means interconnecting the armatures such that the movement of one is always equal and opposite to that of the other, and at least one contact actuated on movement of the armatures, said armature interconnecting means comprising rst and second rigid arms extending one from one armatureand one from the other in a plane perpendicular to that in which the armature pivot axes lie, one arm having a tubular end portion and the other mounting near its end i a rounded portion which iits snugly within the interior of said tubular end portion and lies substantially equidistantly from both armature pivot axes.

2. A relay as claimed in claim l, wherein the rounded portion is a sapphire.

3. A relay as claimed in claim l, further comprising at least one micro switch providing said contact, at least one pin extending from one of said armatures, the nurnber of said pins beingV equal to the number of said micro switches and each pin being located to operate one microswitch on movement of the armatures.

4. A relay as claimed in claim l, wherein said bias on the armatures is provided by a permanent magnet- 5. An electric relay comprising a plate of soft magnetic material forming a base and presenting a pair of parallel edges, a pair of similar plates of soft magnetic material forming armatures, means symmetrically and pivotally mounting said armatures on parallel pivot axes and closely adjacent said ledges of the Vbase whereby a plane perpendicular to said edges is `also perpendicular to thesurface of said armatures, means interconnecting the armatures for movement together symmetrically and in opposite angular directions, a plate-like core of soft magnetic material mounted on said base and parallel thereto by non-ferromagnetic means, said core presenting opposite edge surfaces adapted to contact the surfaces of the armatures when the latter are pivoted towards the core, a coil on the core, energization of said coil, setting up a magnetic circuit through the core, the armatures and the base whereby to pivot the armatures towards said core against a bias, and at least one contact actuated on movement of said armatures.

6. A.l relay as claimed in claim 5, wherein said pivot axes of the armatures contain their centres of gravity whereby each armature has a rst portion to one side of its axis which portion forms part of said magnetic circuit and a second portion to the other side of its axis which portion does not form a part of said magnetic circuit, and said-bias is provided by a permanent magnet mounted on thefbase to the side thereof opposite said core by non-ferromagnetic means, said magnet forming a second magnetic circuit with the second portion of each armature and the base.

7. An electric relay comprising a base, a pair of members mounted upon the base for pivotal movement with respect thereto about parallel axes, means interconnecting said members for symmetrical movement thereof in opposite angular directions, means including a coil rigid with the base to pivot said members against the action of a bias on energization'of the coil, and a Contact arranged for actuation on movement of said members, said interconnecting means comprising iirst and second rigid arms extending one from one said member and one from the other member in a plane perpendicular to that in which the pivot axes of said members lie, one arm having a tubular end portion and the other mounting near its end a ball which ts snugly within the interior of said tubular end portion and lies substantially equidistantly from both pivot axes. i

8. An electric relay comprising a base, a pair of similar armatures mounted upon the base for pivotal movement with respect thereto about parallel axes, a core and coil also mounted, on the base, the core presenting poles to the armature such that energization of the coil causes them to pivot in opposite angular directions against the action of a bias, means interconnecting the armatures such that the movement of one if always equal and opposite to that of the other, and at least one contact actuated on ,movement of the armatures, wherein a permanent magnet provides said bias on the armatures and wherein each armature extends to either side of its pivot axis, the part of each armature to one side of its pivot forming on energization of the coil, a portion of a first magnetic circuit including the core and the base, and the part of each armature to the other side of its pivot axis forming a portion of a second magnetic circuit including the permanent magnet and the case.

9. A relay as claimed in claim 8, further comprising at least one micro switch providing said contact, at least one pin extending from one of said armatures, the number of said pins being equal to the number of said micro switches and each pin being located to operate one micro switch on movement of the armatures.

References Cited in the file of this patent UNITED STATES PATENTS 1,700,890 Hodgkins et al. Feb. 5, 1929 2,353,377 Vaughn July l1, 1944 2,632,820 Gauvreau Mar. 24, 1953