US2455699A - Relay for reliable operation with definite excitation - Google Patents

Description

H. FERRET RELAY FOR RELIABLE OPERA 2,455,699 IIQN WITH DEFINITE EXCITATION Filed Jan. 1944 Dec. 7, 1948.

Patented Dec. 7, 1948 2,455,699 itiiiiiiii FbiiitfiiliA LE OPERATION DEFINITE EXCITATION Henri Ferret, Zug. Switzerland, assignor to tandis & Gyr, A. G., a body corporate of Switzerland Application anti-y 4, 1944, sj riai No. 516,994 In Switzerland December 21, 1942 sect on 1,-1 u'bi o Law stamina 8. int Patent expires December 21, 1962 The present invention relates to relays nd more particularly to relays which are tobe actuatecl with a definite or given excitation, n I

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom; or may be l earned b y practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims. p 1 g The inventionconsists in the novel parts, constructions, arrangements, combinations, and improvements herein shown and described. p

The accompanying drawings, referredto herein and constituting a part hereof illustrate one embodiment of the invention, and. togetherwith the description, serve to explain the principles of the invention. V l v Relays are of very common applicationin elec-' trical engineeringand consist principally of an But no matter ,what type is employed two main groups can be distinguishedjorall relays accorcling to'their application. In the first group the relay has to perform a certain work at aspecified time, which can bevvreadily accomplished by adequate excitation of themagnet. In the second group the relay has to do its work with a definite excitation and even with marginal excitation the movement should be sure and distinct.

The present invention refers to relays of the second group. With such relays, the magnetic force of attraction takes a hyperbolic course in function of the armature distance while the resetting force of the counter-spring is linear. To obtain precise eiiects the resetting spring must be loaded When the excitation of such a relay is brought about; the armature begins to move as soon as the magnetic force of attraction is greater than the load by the resetting spring. As the space between the curve of the magnetic force of attraction and that of the resetting power of the counter-isDringboth powers being shown function of the armature stroke-represents a measure of the working power of the operatiofiS'. g t This eanbe acoiiiplis ea byplacirig' a lead arrangement under at not a spring and ntti ie it tothe relay armature that the latter is retained in "est position and re1e""ii, only upon the emot on j tic force of attraction assoc ation with, uite a definite relay iicit'at In the aeooinpanying qraw ii t re s orpi rpos s or illustration only, certain preferred embodiments o the present invention together with a row di In theiii'awingi 1 i 1 is an example or embodiment as plunger armature relay; I I, j

Fi s. 2 3; 4 n 5 flatma es; rig. 6 illustrates a former an armature I ig.7 example of embodiment as rotary armature relay. l p Fig. 8 sh ws an e'xafiibl oi embodiment hinged armature re ay;

Fig.9a1atra1viev7thr f Fig. it l ustrates a further eiiamiile' of efiitoai mer t oi the rent anymore and Fig 11a lateral 'vi t ereto. R'eferring more p p 'cii1arl'"' to, Fig. 1, the iii: vention is illustrated s comprising a rotati symmetrical relay armature designated Ii b provided at its lowest part with a bulge, anii bear;

ng' a little fu ther up arresting rin 2. The

oou ienit iieec eo ii home: 3 eairies ti e oiioi g winding 4 and isj edfiil'pbd o its lowerfiang' with two lugs orbearingnoses 5 in each of whose centers 5 a toggle lever], is hih'gdai'id movable to a sli ht aterit. The rol er s are borne slightly rotary on one shank ef the togg e evejrs 1. The other wo or the toggl'e'li ers' 1 are tuiii'efci imvaiaiy towards eac other with; their toes linked together y axis I2. A regulating spring l3 fulcruineki at pp'iiit l4 bears fro' rn' b'e aga nst the aiii's 2 and. can best adjusted by,

-' means or set screw It that the rollers t rt urged against the relay armature I in the ante: tiori oi iie'aiio se. v y

The rsettifiibring m isgsjiipportedby the 15in; ll projecting from the upper flange into the interior or the coil power 3 an testis to press therlay armature I downwardly.

come. In addition, the toggle levers 1 must be pressed outwards over the rollers 8 against the action of the regulating spring l3. By the action of the toggle levers 1 upon the relay armature l both the start of the relay armature and its stroke will be influenced in the manner intended.

To make this influence clear, in Fig. 2 has been represented the direction of the magnetic force of attraction PM and the resetting power PF of the counter-spring in function of the armature stroke s. The direction of the magnetic force of attraction PM in function of the armature distance s has a hyp rbolic character, Whereas the resetting power PF takes a linear course. Both these powers act contrariwise to each other. By turning down the curve for Pr round the JC-aXis, the magnetic force of attraction and the resetting force of the spring can be better compared with each other. To obtain neat Work, the resetting spring must be loaded, so that its characteristic does not begin at zero point. A movement of the relay armature takes place only at the moment, in which PMZPF. The hatched space between the curves PM and Pr of Fig. 2 corresponds therefore to the entire capacity for work inherent to the armature at the end of the movement in the form of kinetic energy, that is to say, also, to the capacity for work which the relay is able to exert in fulfilling its duty. This capacity for work compared with that of the relays of the first group mentioned hereinbefore is fairly poor. For a sure timed response of the relay it is particularly important that the angle a between the curves for Pivr=f(s) and Pr=f(s) for the abscissae s=o shall be as great as possible. According to the invention this is achieved by imparting to the curve Pr=f s a sloping instead of a rising course. This modification is attained by the action of the toggle levers 7 upon the relay armature I, whereby it appears quite easy to obtain a favorable outline of the new curve by suitable disposition of the toggle levers l and shaping of the bulge. For the bulge form as per Fig. 3 there is obtained, for instance, a curve G=f(s) according to Fig. 4 for the counter-power. It may be seen therefrom that the curve G=f(s) already represented as turned down in Fig. 4;, does not show any continuous outline, but exhibits unsteadiness at the points a, b, c, d. The explanation of the bend is apparent from Fig. 3, in that the generator of the selected bulge form is composed of three single lines, two straight and one curved. Suppose now the rollers 8 be rolling off consecutively on each of these lines, and the power-path-curve thereby each time determined. One obtains for lin I a right-slope descent of the counter-power G, as the turning moment of the toggle levers I is actually only slightly modified owing to the comparatively small distortion of the lever, whereas, on the other hand, the effective lever arm increases and consequently the counter-power decreases, approximately according to curve I of Fig. 4. When the roller 8 moves over the arc II, it is easy to see that the corresponding curve II has a more pronounced sloping path than curve I, becoming zero for the point with the biggest radius, and negative for the lower portion of the arc, because the counter-power acts now in the same direction as the magnetic force of attraction PM. For line III the action of the roller likewise assists the magnetic force of attraction, and consequently the corresponding curve III in Fig. 4 runs entirely in the negative region, i. e. so that for increasing s the effective power slightly decreases.

In this way the bends a and b of the curve G=f(s) are readily given. The bends c and d ensue at th moment when the contact between the rollers 8 and the armature I suddenly ceases. The power exerted by the rollers upon the armature must then instantaneously become zero.

The opposing force PA which has to be totally overcome by the magnetic force of attraction PM is composed, apart from the weight of the armature, of the counter-power PG exerted by the rollers 8 and the resetting force PF of th counter-spring l0. In Fig. 5 this resulting opposing force PA is represented in conjunction with the magnetic force of attraction PM. The curve P.4=,f(s) is thereby displaced upwards for the load of the counter-spring I0. It appears from Fig. 5, that by this new arrangement the slopin path of the PA-curve, recognised as favorable, is actually attained. In contrast to an ordinary relay, the characteristic of a relay according to the invention reveals the following main advantages:

1. A many times greater angle 0:, whereby a reliable and distinct response with a definite excitation is ensured.

2. Greater capacity for work represented by the larger space enclosed between the curves PM and PA.

Further advantages arise out of the easy adjustability of the response limit by setting the pressure of the regulating spring l3 upon the toggle levers I and by suppressing much the tendency to buzz. The design of the bulge form of the armature I may, of course, differ from that illustrated in Fig. 3 and consequently the characteristic of the relay be adapted to the most exacting requirements. Notably, by suitable selection of the angles on the bulge flank the ratio of the sections A:B in Fig. 5 can be increased or decreased. Furthermore, by modifying the diameter of the rollers 8 and the radius of curvature of the armature bulge, the section C in Fig. 5 can likewise be modified. The value B can for the rest be entirely eliminated, if a shape accord-- ing to Fig. 6 is imparted to the relay armature i. In this case the rollers need only be lifted out of the armature groove to then roll off on the curved surface durin the whole movement without affecting the armature in the direction of the movement either in the one or in the other sense.

The relay armature, moreover, need not be a rotation-symmetrical body, but may have any other suitable shape. It may be also of tubular form as shown in Figs. 10 and 11 and the lead faces may be fitted as special shoulders. In place of two shoulders only one may be provided at a specially appropriate point. For suppressing eddy currents the last mentioned design may, moreovor, be split.

The invention is by no means confined to plunger armature relays, but may be applied to rotary and hinged armature relays as well. Fig. 7 reveals such application to a rotary armature relay and Fig. 8 to a hinged armature one.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advan tages.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. A relay comprising, in combination, an armature, electromagnetic means for moving said armature from a position of rest to a moved position when energized, latching means engageable with said armature to prevent movement toward moved position, disengageable upon predetermined power applied to said armature to permit said movement, and spring means biasing said armature toward said position of rest whereby said latch means may re-engage said armature upon de-energization of said electromagnetic means.

2. A relay comprising, in combination, an armature having a depression in the surface thereof, electromagnetic means for moving said armature in one direction when energized, spring means opposing such movement of the armature and tending to return the armature on deenergization, and latching means engageable with said armature to prevent movement in said direction, disengageable upon predetermined electromagnetic power applied to said armature to permit said movement, said latching means including a latching member for engagement in said depression and resilient means urging said member toward said armature.

3. A relay comprising, in combination, a cylindrical armature having a circumferential rounded depression in the surface thereof, electromagnetic means for moving said armature in one direction when energized, spring means opposing such movement of the armature and tending to return the armature on deenergization, and latching means engageable with said armature to prevent movement in said direction, disengageable upon predetermined electromagnetic power applied to said armature to permit said movement, said latching means including a pair of pivoted elements carrying rounded contacts for engagement in said depression and spring means engaging said elements biasing said elements toward said armature.

4. A relay comprising, in combination, a cylindrical armature having a circumferential rounded depression in the surface thereof, electromagnetic means for moving said armature in one direction when energized, spring means opposing such movement of the armature and tending to return the armature on deenergization, and latching means engageable with said armature to prevent movement in said direction, disengageable upon predetermined electromagnetic power applied to said armature to permit said movement, said latching means including a pair of pivoted elements carrying rounded contacts for engagement in said depression and spring means engaging said elements biasing said elements toward said armature, and means for varying the tension of said spring means upon said elements.

5. A relay comprising, in combination, a cylindrical armature having a circumferential rounded depression in the surface thereof adjacent one end and a circumferential frustoconically formed surface between said depression and said adjacent end, electromagnetic means for moving said armature in one direction when energized, spring means opposing such movement of the armature and tending to return the armature on deenergization, and latching means releasably engageable with said armature said means comprising a pair of oppositely disposed pivoted arms having rounded end portions to engage said armature in said depression and on said frusto-conically formed surface and spring means urging said end portions toward said armature.

6. A relay comprising, in combination, an armature having a rounded depression in the surface thereof, electromagnetic means for moving said armature in one direction when energized, spring means opposing such movement of the armature and tending to return the armature on deenergization, and latching means engageable with said armature to prevent movement in said direction, disengageable upon predetermined electromagnetic power applied to said armature to permit said movement said means including a rounded contact member spring pressed into said depression.

HENRI FERRET.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,126,434 Feller Jan. 26, 1915 1,257,613 Kocourek Feb. 26, 1918 1,538,950 Price May 26, 1925 2,018,479 Zeininger Oct. 22, 1935 2,057,380 Keefe Oct. 13, 1936

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