US2382664A - Electromagnetic operator - Google Patents

Description

W. A. RAY

ELECTROMAGNETIC OPERATOR Aug. 14, 1945.

Filed Nov. '25, 1942 mventor WML/AM A. PAY,

Gttorncn Patented .Aug. 14, i945 UNITED. STATES PATENTv OFFICE ELEcTRoMAGNE'rIc'oPERA'roR William A. Ray, Los Angeles, Calif. .Application November 2s, 1942, serie! N. 466,636

(ol. lis-336) i 13 Claims.

' My present, invention relates to low energyconsumption electromagnetic operators, and particularly to those o1 tire iron-clad single-workingm'eans also servingl as a support for the electro- I magnet.

can type. Q

In my copending application, Serial No. 456,358, filed August 27, 1942, nowv Patent No. 2,358,828, granted September 26, 1944, I have disclosed an electromagnetic operator, oi' the series workinggap type. the energy consumption of which is- -very small in comparison with that ci electromagnetic operators of conventional form and capable of performing equivalent work; the imforce) is at apoint considerably below the knee oi.' the magnetization curveior the corek material, the flux density in the large-area pole lace is substantially the same as that which couldbe produced by the weak magnetizing force if the cross-sectional area of the body of the core were! not reduced; reduction of the body area making possible the use of a coil winding of small mean turn diameter and correspondingly smalleiectrical resistance. It is a general object of the present invention to apply similar principles to provide a' low energy-consumption electromagnetic operator of the single working-gap type. The device disclosed in the aforementioned copending application, while obviously not so limited, was designed for energization by a minute amount of electrical power, such as that available from a Another object is the provision of means for reducing the reluctance o1 the ilxed air-gap of an ironclad electromagnetic operator. g

Other objects and advantages of the invention will be found in the description, the drawing, and in the claims; and for full understanding of the invention, reference may be had to the following ldetailed description and accompanying drawing,

whereini. l

Figure 1 is a sectional view oi.' an electromagnetically operated fluid control valve embodying my invention: ,and

Figures 2 and 3 are sectional views of modified forms of electromagnetic operators embodying the invention.

Referring iirst to Fig. l of the drawing, the numeral ii indicates a valve casing having a partition i2, in anpening through which partition- -isthreaded a valve port and seat member i2. Secured to the open top end of the valve casing is a cylindrical hourng I6, of non-magnetic material, which supports an electromagnet compriswall o! the outer core portion and is removably thermoelectric generating device heated by an pole Yface 22.

ject being the provision ,of an operator of that type which has an annular pol face formed by a ilanged portion of its outer shell.

, `Another object is the provision, in an electromagneticoperator, oi the general type described, of non-magnetic means for preventing direct ensagement of the armature with the pole face, and. for sealing the interior oi the electromagnet; the

secured thereto by screws. or bottom, end of the inner core portion I6 is a cup-shaped enlargement or head i8 of magnetic material; and surrounding the portion Ii is an energizing coil winding i9 having external leads 2U. 'I'he opening in the outer core portion, covered by the plate il, is of such size that the coil and inner core." assembly can be withdrawn from the electromagnet' tor replacement by a similar unit. The open end of the cup-shaped outer core portion I5 is inwardly turned to form a ange 2 i, the underside of this nan'ge providing an annular The flange 2i Ais secured, as by welding, Ito the top. walljfr the non-magnetic housing i4, which wall is oi reduced thickness and has a central depression, formed by a cup-shaped portion 23, closely conforming to the entire outer surface of the cup-shaped inner core head i8.'

Slidable on this head, andmagnetically separated therefrom by the portion 23, is a ycup-shaped ar= mature 24 -having'an annular flange 25 extending from its open end, which flange cooperates with the pole face 22 to define the single working-gall'Y 28 of the electromagnet; the "fixed" air-gap being formed by the side wall of the non-magnetic portion 2l. Attached to the end wall 21 of the arma- Welded to the free,

t-ure is a closure member 28 cooperable with the seat member i3; and interposed between.' the armature and the closure member is a flexible perforate diaphragm 29, of finely woven wire, which is secured at its margin between the valve casing and the housing i4. This diaphragm, while permitting equalization of the fluid pressures on its opposite sides, serves to prevent entrance of for eign matter, carried by the controlled fluid, to the 'sliding surface of the armature.

The cup-shaped outer core portion i5 is constructed of material of such thickness that its effective cross-sectional area is substantially equal to that of the inner core portion I6; and the considerable space provided between the coil winding I9 and the side wall of the outer core portion minimizes nux leakage between these parts. 'I'he area of the annular pole face 22 is obviously many times that of the cross-section of the inner core portion IB, so that the flux density in the working-gap 26 is very low; the relative proportions shown in Fig. 1 being-those preferred when the magnetizing force is of the order of that produced by a pilot-burner-heated thermoelectric device; it being borne in mind that, due to the relatively small diameter of the core portion I6, the mean turn diameter and electrical resistance of coil i9 are correspondingly small. In modified forms of the electromagnet shown in Fig. 1, the ratio between `the areas of the pole face and inner core cross-section may be as low as 4:1 or 2:1 when the magnetizing force is relatively high, but still considerably below the knee of the magnetization curve for the particular material employed.' By' bending the anges 2i and 25 so that they are al; corresponding inclined angles, the area of the working-gap can be increased without increasing the external dimensions of the electromagnet; however, when the angle of inclination is large, the actual pull is not greatly increased, due to the unuseful transverse flux then produced in the gap. Due to the large area of the side surface of the inner core head I8. the flux density in the fixedv air-gap between it and the armature is low, and the losses in this part of the magnetic circuit thus minimized. It will be observed that when the amature 2l is in attracted position with its flange 25 separated from the pole face 22 only by thenon-magnetic top wall of housing Il, there is a considerable space between the end wall 21 of the amature and that of the head I8 so that that space therefore does not constitute a Yworkingaap, and the end wall of the armature could be` eliminated without materially'aecting the operation of the electromagnet; however, the i construction shown'is preferred since it affords convenient means for connecting the armature to the device to be operated. and also aids to some degree in conductionk of the flux. The draw-formed" portion of housing I4 serves not only as a magnetic separator between the Working-gap flanges 2l and 25 and between, the armature and the inner core head, but also as a fluid seal for the electromagnet when it is employed in a valve struc- Referring now to the modified form of electromagnetic operator shown in Fig. 2, the numerals X3i and I2 indicate a pair of cup-shaped core portions' which are intimately joined together by tightly lapping the mouth of one over that of the other, screws 3l serving to secure the junction. Attached, as by welding, to the end wall of4 the upper core 'portion 2| is a cylindrical inner core Portion ll having at its free end a cylindrical stop or head", of the same material as the core portion, the underside 36 of which forms the pole face of the electromagnet. Welded in a central opening through the end wall of the lower cupshaped portion 32, and so arranged that it extends to a considerable distance from either side of the wall, is a sleeve 31 of magnetic material. A press-fit within this sleeve is another sleeve 28, of thin non-magnetic material, having at its inner or upper end, immediately above the corresponding end of the outer sleeve, a flange 39. A sliding fit within the inner sleeve is a magnetic plunger Ill, the outer end of which is adapted to be connected to a device to be operated. The plunger has atfiis upper end a cylindrical head 4|, also of magnetic material, the top surface of which defines with the pole face 36 the workinggap of the electromagnet. Direct engagement; of the heads 35 and 4I', when the electromagnet is energized, is prevented by a non-magnetic button 42 set in the lower head; and, when the plunger is in its unattracted position as shown, the underside of its head is separated from the magnetic sleeve 31 by the non-magnetic flange J9. The adjacent surface areas of the heads 35 and Il are several times greater than the cross-sectional areas of the core portion 3l and plunger l0, re spectivelv, but the heads are' preferably of such diameter that the space between them and the outer core portions is large enough to prevent material lateral leakage of flux` For energizing the electromagnet, a pair of coil windings 43 and 44, connected in aiding relation and having external leads I5, are provided; one winding surrounding the core portion 34, and the other the magnetic sleeveil. Due to the large surface area of the sleeve 31 adjacent the plunger 4U, the reluctance of the fixed air-gap between these parts is relatively low. To increase the flux-conducting capacity of lthe end walls Cof the outer coreportions` electromagnet. A press-fit in the open end of the core portion 5Fis' a cup-shaped member 54. of thin non-magnetic material, the end wall of which is forced into close engagement with the core head 53. The member 5l serves both as a magnetic separator and also as a seal for the interior of the electromagnet, and has at its open end a thickened flange 55 whereby the electromagnet can be mounted, as on a valve casing. Slidable within the member 54 is a cup-shaped armature 56, having a stem 51 for connection to a device to be operated, which armature is -attracted toward the inner core head 53 when the electromagv net is energized by passage of current through its coil winding 68. It will be observed that this form of the invention also embodies the features of providing a large-area working-gap, and a low-reluctance fixed air-gap.

While I have hereimshown and described specific embodiments of my invention, I wish it to be understood that modifications may be made without departing from the jspirit of the invention,

and that I intend therefore to be limited only by the scope of the appended claims.

I claimas my invention:

1. In an electromagnetic operator of the single working-gap type: a core member having a generally cupsha ped outer portion and an inner pora lcoil winding in said space.

2. In an electromagnetic operator of the single working-gap type: a core member having a generally cup-shaped outer portion and an innerl portion extending substantially centrally from the end wall of the outer portion to define ltherewith a space for an energizing coil winding, said cupshaped portion having a ange extending from its open end to form a pole face of substantial area: said inner core portion being enlarged at its free end; an armature reciprocably mounted on said enlargement of the inner core portion and in good flux-transfer relation thereto, said armature having a. surface defining with said pole face a working-gap; and a coil winding in said space.

3. In an electromagnetic operator of the single working-gap type: a core member having a generally cup-shaped outer portion and an inner cup-shaped head, slidable on the portion of said non-magnetic member surrounding the side wall of said cup-shaped head, said armature having a flange' extending from its open end which provides a surface defining with said pole face a working gap; and a coil winding in said space and surrounding the unenlarged part of said inner core portion. 1V.

6. Inanelectromagnetic operator of the single working-gap type: a core member having a senerally cup-shaped outer portion and an inner portion extending `substantially,centrally lfrom the end wall of the outer portion tog define therewith a space for an energizing coil winding, Asaid cupshaped portion having a-fiange extending from its open end toL7 form a pole face of substantial area; said inner core portion having at its free end a cup-shaped head, inverted in relation to said cup-shaped core portion; a member ofthin non-magnetic material having a portion covering said poleface and another portion closely surrounding the side and end walls of said cup-v shaped head; an armature of cup-shaped form,

l corresponding to that of said cup-shaped head,

portion extending substantially centrally from the end wall of the outer portion to define therewith a space foran energizing coil winding, said cupshaped portion having a ilange extending in-v slidable on the portion of said non-magnetic member surrounding the side wall of said cup-shaped head, said armature having. a flange extending from Aits open end which provides a surface defining with said pole face a working gap; and a coil winding in said space and surrounding the unenlarged part of said inner core portion.

wardly from its open end to form a substantially J .plane pole face of substantial area; an amature having a substantially plane surface defining with said pole face a working gapsaid armature being reciprocably mounted on said inner core portion for movement of said surface toward and away from said pole face; and a coil winding in said space.

L In an electromagnetic operator of the lsingle working-gap type: a core member having a generally cup-shapedouter portion and an inner portion extending substantially centrally from the end wall oi' the outer portion to deilne therewith a space for an energizing coil windinga said cupshaped portion having a flange extending from its open end to form a substantially plane pole face of substantial area; said inner core portion being enlarged at its free end; an amature of generally cup-shaped form, and inverted with respect to said cup-shaped core portion, reciprocably mounted-on said enlargement of the inner core portion and in good ux-transfefr relation thereto, said armature having a flange extending from its open end providing a surface defining with said pole face a working-gap; and a coil winding in said space.

5. In an electromagnetic operator of the single working-gap type: a core member having a generally cup-shaped outer portion and an. inner portion extending lsubstantially -centrallyfrorn the end wall of thel outer portion to define therewith a space for an energizing coil winding. said cupshaped portion having a flange extending from its open end to form a pole face of substantial area;

7, In an electromagnetic operator of .the single working-gap type; a core member having a generally cup-shaped outer portion and an inner portion extending substantiallycentrally from the end wall of the outer portion to define therewith a space for an energizing coil winding, said cup-shaped portion having a flange extending i from its open end to form a pole face of substanf;` tial area; said inner core portion having at its free end a cup-shaped head, inverted in relation to said cup-shaped core portion; a member of thin non-magnetic material having a portion covering said pole face and another portion closely sur rounding the side and end walls of said cupshaped head.; an armature slidable onv the portion of said non-magnetic member surrounding the side wall of said cup-shaped head, said armature area; said inner core portion having an enlarge` ment at itsfree end; a member of thin non-mag netic material having a portion covering said pole face and another portion closely surrounding said said inner core portion having at its-freeend a cup-shaped head, inverted in relation to said cupshaped core portion; a member of thin non-mag.- \netic material having a portion covering said pole face and secured thereto, another portion closely surrounding the side and end walls of said cupshaped head. and a thickened marginal portion extending outwardly beyond said flange to form a support for said core member: an armature of cup-shaped form, corresponding to that of said enlargement of the inner core portion: an armature slidable on said other portion of said nonmagnetic member and having a surface defining with said pole facea working-gap; and a coil winding in-said space and surrounding the unenlarged part "of said inner core portion.

9. In an electromag-netic operator of the single working-gap type; a core member having a generally cup-shaped outer portion and an inner por tion extending substantially centrally from the a space for an energizing coil winding, said cupshaped portion having a flange extending from its open end to form a pole face of substantial area; a member of non-magnetic material secured to and covering said pole face, and having an outwardly extending portion serving as a support for said core member; an armature reciprocable with respect to said inner core portion and in good iiux-transfer relation thereto, said armature having a surface defining with said pole face a working-gap; and a coil winding in said space.

l 10. In an electromagnetic operator of the single working-gap type: a core member having a generally cup-shaped outer portion and an inner portion extending substantially centrally from 'the end wall o! the outer portion to define therewith a space for an energizing coil winding; said inner core portion being enlarged at its free endl to form, Within said cup-shaped portion, a pole face the area oi'. which is at least several times greater than the cross-sectional area of the unenlarged part of the inner core portion; a. generally cupshaped member of thin non-magneticl material core-portion being enlarged at its free end to form, within said cup-shaped portion, a. poleiace the area of which is at least several times greater than the cross-sectional area of the unenlarged part of the inner core portion; a generally cupshaped member of thin non-magnetic material closely received in the open end of said cupshaped core portion, and so arranged that the of said armature with said pole face, comprising closely received in the open end of said cupshaped core portion,` and so arranged that the outer surface of its' end wall is in engagement with said pole face, said cup-shaped member hav-y ing at its open end a ange which serves as a supportfor said core member; an armature slidable in Said cup-shaped member, the inner surface of said armature defining with said pole face a working-gap; anda coil winding in said space and surrounding said unenlarged part yofI the4 inner core portion. l

11. In an electromagnetic operator of the single working-gap type: a core member having a generally cup-shaped outer portion and an inner portion 'extending substantially centrally from the end wall of the outer portion to define therewith a space for an energizing coil Winding; said inner an integrally formed member of non-magnetic material having a medial portion closely covering said pole face and end portions forming a support for the core member, said medial portion being reduced in thickness.

13. In an electromagnetic operator: a fixed core member having an energizing coil winding and providing a pole face; an armature arranged for attraction toward lsaid pole face when the core is energized; and means for supporting said core member and for preventing direct engagement of said armature with said pole face, comprising a -member of non-magnetic material having a portion closely covering said pole face and extending therebeyond to form a support for the core member.

WILLIAM A. RAY.

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