US2675508A

US2675508A - Electromagnetically controlled operator

Info

Publication number: US2675508A
Application number: US331850A
Authority: US
Inventors: William A Ray
Original assignee: General Controls Co
Current assignee: General Controls Co
Priority date: 1953-01-19
Filing date: 1953-01-19
Publication date: 1954-04-13
Anticipated expiration: 1971-04-13

Description

April 13, 1954 w. A. RAY 2,675,508

ELECTROMAGNETICALLY CONTROLLED OPERATOR Original Filed Aug. 20, 1945 2 Sheets-Sheet 2 lSnnentor:

WILL/AM A. PAY,

Bu 6/wu W C(ttorneg.

Patented Apr. 13, 1954 ELECTROMAGNETICALLY CONTROLLED OPERATOR William A. Ray, North Hollywood, Calif., assignor to General Controls 00., a corporation Continuation of application Serial No. 611,597, August 20, 1945. This application January 19. 1953, Serial No. 331,850

This invention relates to electromagnetically controlled devices of the type wherein an electromagnet is employed for retaining an armature in attracted position after it is first brought to that position by mechanical means; the electromagnet being so designed that it is incapable of attracting the armature through space. The present application is a continuation of an application, Serial No. 611,597, filed August 20, 1945.

Devices of the character described have their chief utility in connection with safety control systems wherein energization of the electromagnet is so controlled by means responsive to a condition, which is a prerequisite to safe operation of the system, that in the event of cessation of the condition the armature is released and thereby effects such control of the system that the same is rendered inoperative; it then being necessary to manually reset the armature after the cause of the trouble has been corrected.

Typical of such a system is one wherein the armature is connected to a valve for controlling supply of fuel to a main burner and is normally retained in a valve-opening attracted position due to the current generated by a thermoelectric device subjected to the flame of a pilot burner for the main burner. Especially since the amount of power produced by such a thermoelectric generating device is relatively minute, it is obviously Claims. (Cl. 317-175) desirable that the armature should hold in and drop out (in the event of extinguishment of the pilot flame) at predetermined respective values of the energizing current; however, in previous devices of this character these respective current values have been found to vary considerably in at successive operations of the same device. It is, therefor, an object of this invention to prevent such erratic action, and I have found that this object can be accomplished by sliding together the cooperating surfaces of the armature and the core of the electromagnet so that the degree of intimateness of contact between these surfaces is substantially the same each time the armature is reset.

I have further discovered that by plating one or both of the cooperating surfaces of the armature and core with a thin layer of hard nonmagnetic metal, such as chromium, not only are the surfaces protected from wear, but also that, due to the non-magnetic barrier between it and the core, the armature is released each time the holding current is reduced to substantially the same value.

For full understanding of the invention and further appreciation of its objects and advantages, reference is to be had to the following detailed description and accompanying drawing, and to the appended claims.

In the drawing:

Figure 1 is a longitudinal sectional view of a valve embodying the invention;

Figure 2 is a fragmentary transverse section taken along the line 2-2 of Fig. 1; and

Figure 3 is a longitudinal sectional view of a modified form of valve embodying the invention.

Referring first to Figs. 1 and 2 of the drawing. the numeral ll indicates a valve casing having axially aligned inlet and outlet openings l2 and l 3, respectively. Cooperable with a seat 14 formed at the inner end of the outlet opening is a closure member I5 mounted on a rod l6, which rod is guided at its right-hand end in an apertured cup-shaped washer 'I'l pressed in the inlet openin l2. The left-hand end of rod [6 is guided by a vaned member I8 secured thereto and freely slidable in the outlet opening l3. A spring [9, compressed between an enlarged portion of the rod and the washer ll, urges the closure member toward its seat. Covering an opening in the upper wall of the casing and secured thereto is a housing 2|. Interposed at its margin between the flanged lower portion of this housing and the surface of the casing surrounding the opening is a corrugated metallic diaphragm 22. Extending from the underside of the diaphragm is a U- shaped closure-operating member 23, in the lower portions of the side arms of which are pins 24, freely received in an annular recess formed in the enlarged portion 20 of the rod l 6. The member 23 is secured to the diaphragm by a bolt 26 which extends through an opening concentric of the corrugated portion thereof. Also secured to the diaphragm by the bolt 26, with a bushing 21 therebetween, is a cross-shaped lever 28. The arms 29 of this lever'are provided at-their do'wnwardly-turned outer ends with knife-edged portions 30 which bear in V-shaped notches cut in upwardly-turned lug portions 3| formed on the lower end of a sub-housin 32, which sub-housing fits snugly Within the main housing 2|. The lever 28 is thus pivoted substantially in the general plane of the diaphragm 22, and is held in that position by the force of a pair of springs 33 compressed between the arms 29 (Fig. 2) and the upper wall of the sub-housing 32. The pivots of the lever also being on a line Which intersects the longitudinal axis of member 23' at the diaphragm, no appreciable amount of fluid is displaced in the flexing of'the diaphragm as the lever is rocked, and for the same reason, the fluid pressure below ture. permits accuratealignment of its upper surface faces.

the diaphragm has no tendency to rock, or impede rocking of, the lever. So that the springs 33 will not produce a toggle action when the lever is rocked, the arms 29 are provided with depressed portions 34 for receiving the springs so that their lower ends are substantially in the axis of rotation of the lever. The cross-shaped lever 28 has an additional pair of arms 3535 which extend at right-angle to thearrns 29..

Mounted in the upper part of the housing-2| is an electromagnet comprising a U-shaped core 40, the upper end of whichis received. in a recess 4| formed in the top wall of the housing Surrounding one of the side arms of the U-shaped core is a coil 42, the leads 43, of which extend through an opening in the side wall of the housing and are connected to terminals 44 insulatingly mounted in a bracket 45 secured to-the housing. The side arms of the core extend through openings in the top wall of the sub-housing; and the i electromagnet is maintained in position by its coil.

Cooperable with the pole faces-l6 of the core is an armature 41 which is rockably mounted on an up-set. end portion '48 of the arm 36, the armature being resiliently held to the arm by a leaf spring 49 compressed against the inner surface of the head 50 of a pin secured to-the arma- This rockable mounting of the armature 51 with the pole faces 46 when these surfaces are brought together.

Reciprocable in aligned openings formed in the top walls of housingZl and sub-housing 32 is a rod 52, the outer end portion 53 of which forms a manually operable push-button. Compressed between a shoulder .56 for-medon rod 52 and the upper wall of the sub-housing 32 is a spring 54 a which urges the rod upwardly, its movement in this direction being limited by the shoulder 56. The rounded lower end of rod 52 engages a cupped portion 55 of lever arm 35, downward movement of push-button 53 serving to rock the lever about its pivots sothat the closure member I5 is moved into open position and the surface 51 of armature 41 is simultaneously brought into engagement with the pole faces 46 of the core.- It, When this occurs, the core is sufficiently-energized by passage of current through coi1'42, upon release of push-button 53, since the armature isthen magnetically held in engagement with the .pole

faces, the closure member is retained in open positionagainst the bias of spring. l9.. 'If the current through coil 42 is interrupted or sufliciently weakened, the armature is released from the core and the valve closes.

Inasmuch as thelever.28. is pivoted on an axis remote from the plane of the core pole-faces 46, after thearmatureis brought into engagement ;with the,core continued pressure on the, push- ,button 53 effects a slight relative. sliding movement ofthe

surfaces

46 and 51,, due to the in herent yieldability of the lever-arm 36,50 that they are intimatelyinterengaged; uniform cooperation of the core and armature thus being ensured each time the armature is reset.

This sliding movement is effected because the force urging the armature 41 against the core 40 has a direction obliqueto the interengaging sur- This force has a component parallel to the interengagingsurfaces. Since the lever 36 can yield,. continued pressure on button 53 inevitably cause th sliding movement. 5

One orboth of the ,cooperating'surfaces 46 and '51 is preferably plated with a thin-layer (00001- 00002 inch thick) of chromium. Due, presumably, to the non-magnetic barrier between the magnetic members formed by this layer, I have found that after each resetting of the armature its release occurs when the electromagnet-current is reduced to substantially ,the same value.

In previous devices of this character it is well known that the drop-out value of the current may at times vary more than 100%. Further, since the chromium layer is very hard and substantially non-corrosive, the surface wear is reduced to a minimum.

Referring now to the modified embodiment of the invention shown in Fig. 3, the numeral GI indicates a valve casing having inlet and outlet chambers Stand 63, respectively, separated by a partition 64 the vertical portion of which is provided with a valve port 65 having around its inlet end an annular valve seat 66. In the bottom wall of the casing are openings, shown closed by a pair of plugs 61, which can serve as pilot. tappings .-when the valve. is employed for controlling supvplyv of gaseous fuel to main and pilot burners.

,Above the top wall of partition 84, and joined integrally to the front and back walls. of the resilient seat-engaging disk-14. Theleft-hand extremity of the horizontal portion of leverilO is formed to provide a dependent finger ,'l5-which bears ina cup 16 provided in the upper; end of a compression spring "which serves to bias the lever in a clockwise-direction; the lowenend of the spring being received in a recess .18, formed his thickened portion of the top wall of partition64. Covering the opentop of 1 casing 6| is adiaphragmJEB, of flexible material such asleather or thin metal, which-is clamped at its margin between the casing and the flanged mouth of a cup-shaped. housing 86 secured to-the casing.

Forming within housing an extensiontof lever .10 is a channelled arm Bl which isv secured by screwsto the horizontal portion of the levenwith diaphragm 19 therebetween; theconnection between these parts being fluid-tight. ,Reciprocable in abushing 82, sealingly secured in an. opening through the top wall of housing 80, is a pushbutton 83 having a stem 84 engageable with the left-hand end of thearm ll. The bushing 82 ..is preferably externally threaded, asshown, for v the attachmentof a protective cap,;or for the connection of means'for remotely ,operatingthe -push-button. The stem, 84; extends. ,freely through an o pening in/the bottom wall of-a relatively-narrow rectangular receptacle 85 which is I secured in position by a sheet-metal member 86 spot-welded to thetop wall of housing 30 and havingears (not shown) which cooperate with slots in theside wallsof the receptacle. When the push-button 83 in its retracted position, as

shown, the clearance-opening around it is sealed by. cooperation of its enlargement Bland soft washer 88 with the undersurface of bushing 82;

the push-button being biased tothis position by a compression spring 89 encircling thestem 84.

Within the right-hand end of receptacle 85 is anelectromagnet comprising a .U -shaped core -90 around one side arm ofwhich is ,an energizing coil 9! having leads 92 which are connected, as

by solder, to the inner ends of terminal-posts 93 sealingly and insulatingly mounted in openings through an end wall of housing 83. The electromagnet is held in place by the receptacle 85 and by a cooperating cupped member lei which fits within. the expanded mouth of the receptacle; the side arms of the core fill extend ing freely through openings in the member Hit and corresponding openings in the bottom wall of the receptacle. A piece of fibrous material or fish-paper I82, is inserted below the coil 9!. so as to prevent the possibility of dirt, or flakes of the insulating compound with which the coil is customarily impregnated, from falling through the core-openings in the receptacle.

Secured by a rivet 96 to the top wall of the housing is a name-plate 95 having an opening in register with an opening 96 through a portion of the top wall of the housing which is dished to receive a glass or plastic window 91 and sealing gasket 58; the shouldered margin of the window being engaged by the name-plate. The window is preferably in the form of a magnifying lens, as shown, and permits observation of an indicator 99 which conveniently consists of a U- shaped wire extending through a slot Hill in the bottom of receptacle 85, the lower extremities of the wire being bent for reception in openings through the opposite side walls of the channelled arm 8!. When the lever l0, 8! is rocked, the cross-arm of the indicator is moved to opposite ends of the window so that the position of the lever can readily be ascertained.

Cooperable with the ends or pole-feces Hit of the core 91] is an armature HM which is yieldably and rockably mounted on the right-hand end of the lever-arm ill by means of a headed pin I05 riveted to the arm and freely extending through a central opening in the armature, the armature being urged by a compression spring I06 against the head of the pin, for which head a shallow recess is provided. When, by operation of the push-button 83, the lever is, 3| is rocked from its position shown, the closure member H is brought to open position and the armature is moved arcuately so that its surface I01 engages the pole faces its, continued movement of the lever effecting depression of the armature against the force of spring I95 so that the armature slides on the core and these parts are intimately interengaged. If when this occurs the core is suiiiciently energized by passage of current through the coil as, upon release of the push-button the lever is retained in its moved position, against the bias of spring ll, by the force of the electromagnet. When the electro-- magnet is sufficientiy deenergized, the armature is released and the valve closes.

Because of the relatively rigid construction of the arm 8! it is necessary to mount the armature yieldably in order to effect the desired intimate interengagement of the armature and core; in the embodiment of the invention shown in Figs. 1 and 2 the inherent resilience of the arm 36 is sufficient to permit such action. One or both of the cooperating surfaces H33 and dill is preferably chromium-plated for the reasons stated in connection with the corresponding surfaces 46 and 5'! in the embodiment of Figs. 1 and 2.

In this form, the force applied to the armature M4 is oblique to the interengaging surfaces; and since the mounting of the armature permits yielding, a sliding movement of the ar- 6 mature is effected upon continued pressure on button 83.

While I have herein shown and described specific embodiments of the invention, it will be understood that modifications may be made without departing from the spirit of the invention and its scope as defined by the appended claims.

I claim as my invention:

1. In an electromagnetically controlled device: an electromagnet, fixed with respect to said device, comprising a core member having a plane polar surface, and a coil in flux-inducing relation to the core member for energizing the same; a movable armature member having a plane surface cocperable with said polar surface of the core member; said electromagnet when energized being incapable of attracting said armature member through space, but adapted while, and only while, energized to retain the armature member in engagement with said core member after said surfaces are first mechanically brought together; and a lever member, pivoted on said device on an axis other than in the plane of said polar surface, for supporting the armature member and movable to swing the armature member arcuately into engagement with the core member, said lever member being so constructed that it can yield to a limited extent so that after initial engagement of said surfaces a sliding movement of the surfaces is effected.

2. In an electromagnetically controlled device: an electromagnet, fixed with respect to said device, comprising a core member having a plane polar surface, and a coil in flux-inducing relation to the core member for energizing the same; a movable armature member, of rigid construction, having a plane surface cooperable with said polar surface of the core member; said electromagnet when energized being incapable of attracting said armature member through space, but adapted while, and only while, energized to retain the armature member in engagement with said core member after said surfaces are first mechanically brought together; and a lever member, pivoted on said device on an axis other than in the plane of said polar surface, for rockably supporting the armature member and movable to swing the armature member arcuately into engagement with the core member, said lever member being so constructed that it can yield to a limited extent so that after full engagement of said surfaces a sliding movement of the surfaces is effected, whereby intimacy of the engagement of the surfaces is ensured.

3. In an electromagnetically controlled device: an electromagnet comprising a core member and a coil in flux-inducing relation to the core memher for energizing the same; an armature mem her; said members having interengaging plane surfaces; said electromagnet when energized being incapable of attracting said armature member through space, but adapted While, and only while, energized to retain the surfaces interengaged after the surfaces are first mechanically brought together; a support carrying one of the members; means for applying a force to the support to cause the members to be brought into full interengagement; and means determining the path of movement of the said one of the members so that the direction of the force urging the members together is oblique to the surfaces when the surfaces are in full engagement; said support including means yieldable in such mannenas to causera. sliding movement between the surfaces upon continued application of the force after the surfaces are brought into full en agement..

4. In an electromagnetically controlled device: an electromagnet comprising a core member and a coil in flux-inducing relation to the core member for energizing the same; an armature member; said members having interengaging plane surfaces; said electromagnet when energized being incapable of attracting said armature member through space, but adapted while, and

only while, energized to retain the surfaces interengaged after the surfaces are first mechanically brought together; a support carrying one of the members; means for applying a source to the support to cause the members to be brought into full interengagement; and means determining the. path of movement of the said one of the members so that the direction of the force urging the members together is oblique to the surfaces when the surfaces are in full engagement; said support including parts capable of relative movement, for causing a sliding movement between the surfaces upon continued application of the force, after the surfaces are brought into full engagement.

5. In an electromagnetically controlled device: an electromagnet comprising a core member and a coil in flux-inducing relation to the core memher for energizing the same; an armature member; said members having interengagms plane surfaces; said electromagnet when energized being incapable of attracting said armature member through :space, but adapted while, and only While, energized to retain the surfaces interengaged after the surfacesare first mechanically brought together; a support carrying'one of the members; means for applying a force to the support to cause the members to be brought into full interengagement; and means determining the path of movement of the said-one of the members so that the direction of the force urging the members together is oblique to the surfaces when the surfaces are in full engagement; said support including a loose connection between the support and the said one member, for, causing a sliding movement between the surfacesupon continued application of the force after the surfaces are brought into full engagement.

References Cited in the file of this patent UNI-TED STATESPATENTS Number Name Date 1,302,817 Leonard May 6, 1919 1,499,421 Stoekle July 1, 1924 1,560,308 'Perry Nov. 3, 1925 1,981,259 Wertz Nov. 20, 1934 2,245,834 Sparrow June 17, 1941 2,324,891 Thumin July29, 1943 2,343,861 Biggle Mar. 14, 1944 2,351,377 Warsher June 13, 1944