US1697142A - Material for magnetic apparatus and process of making same - Google Patents

Description

Jan. 1, 1929. y 1,697,142

L. H. ROLLER j MATERIAL FOR MAGNETIC APPARATUS ANDPROCESS F MAKING'SAM Filed Nov. 21, 1925 Patented Jan. 1, 1929.

UNITED STATES PATENT OFFICE.

LOUIS H.. ROLLER, F WHITE PLAINS, NEW YORK..

MATERIAL ron MAGNE'rIc Arrana'rns AND :enocnss or MAKING SAME.,

Application led November "211925. Serial No. 70,687.

is mechanically strong, Water proof, gas" anon-conductor of high reluctance to but proof and in the main, electricity and offering a the passage of magnetic lines of.v force,

having therein clearly nagnetic reluctivity.

It is a' well known practice to pass magnetic lines of force through the walls of a sealed Container to container instead of transmitting power by means of moving mechanical elements passing through the wall with the consequent danger of leakage around suchv elements. However, in order to avoid serious losses due to eddy currents, such walls must be made of electrically non-conducting mate-,

rial. On the other hand this has heretofore limited one to the use of materials that have a high magnetic reluctance, have had to be Very thin to avoid serious losses due to leakage of magnetic fiux.

It is' an object of the present invention to provide a material which overcomesl these objections by providing a material which is not subject to appreciable eddy current losses, in which a low magnetic reluctance is pro'- vided Where desired, and which, therefore,A

will provide a wall ofconsiderable thickness Without entailing material losses due to magnetic leakage. l

A specific use of my improved material will be found in my co-pending application, Se- .rial No. 710,680, filed May 2, 1924:, which described an electro-magnetic pump in which magnetic lines of force were passed through a sealed cylinder into an armature to reciprocate the latter and in which the cylinder was made of non-metallic material containing zones of low reluctance formed by embedding soft iron particles in the material.

It will be obvious that there would be many other-uses to which the material could be applied, in certain of which it would be desirable not to form the material in cylinders but to form it in other shapes.- Furthermore, if formed in cylinders certain uses would require that the regions of low reluctance be arranged transversely to the axis of the cylinder while in other cases the regions of low reluctance shouldbe arranged parallel to the axis of the cylinder.

defined paths of low,V

perform work within the.

s that the walls In producing the material I employ a woven fabric of clothy in which fine threads of soft iron orV other metal of high magnetic permeability are interwoven, the wire forming stripes in the lmpregnated with certain well knownphenol condensation products and built up to any desired thickness by coiling it or piling it in layers with the, stripes superposed. Thereafter the coil or pile is subjected to a heat and pressure to form a bakelite orcondensite mass in which the wires are embedded'.

I am aware'that it is not new to lembed vmetallic'wires in bakelite or condensite, a

patent on' such material having been Agranted to John Taylor, December 12, 1922, No. 1,438,875. However, the material described cloth. The cloth is-then in said patent was designedwith'an entirely different purpose in View, viz,that of strength so that the material could be used for gears and similar mechanical elements. Such material would be entirelyl unsuitable for my purpose, uniformly distributed throughout the material and must necessarily be so distributed for-the purpose of giving uniform strength. But it will be evident that while such material would reduce the magnetic reluctivity such magnetic qualities would be uniformly distributed through the material and would defeat the purpose for which I intend-to use my material. For the purpose I have in view'it isessential that deiined regions of low magnetic reluctance should be provided and that these regions beseparated by regions of high reluctance otherwise 'there wouldbelittle advantage in using the material disclosed by Taylor cited, over that of using a continuous sheet or tube of'iron. It is therefore, an objectof my invention toprovide avmaterial in which the regions of low reluctance are separated by regions of high reluctance Wit no physical joint between vsuch regions.

I also believe that I am the first to produce "a fabric With separate stripes of iron wlre woven therein Heretofore, metallic wires have been interwoven with threads of tex-4 tile material but the materialcontained wires running lengthwlse as well as transversely to the material and was not confined to mate-A 'having stripes of wire running in one direcv because the metallic strands are tion only and to provide an eicient process for making suchY a fabric.

Thesrt and other objects I attain as hereinafter set forth, reference being had to the accompanying drawings in which Figure l is a diagrammatic perspective viewot' a piece of fabric provided with threads of soft metal interwoven with nonmetallir threads;

Fig. 2 is an edge view of a sheet of my improved material showing the iron wires arranged in layers vertically alincd;

Fig. 3 is a view similar to Fig. 2 representing a. modified form of my material in which the layers ot' iron wires are arranged in staggered relation to form inclined paths of low reluctance through tlnl material;

Fig. 'i illustrates one application of my material showing in longitudinal cross aection a fragmentary view of a magnetically operated pump having a cylinder of my improved materlal. the pump being similar in form to that disclosed in the aforesaid eopendingr application;

Fig. 5 represents another application of my material illustrating a rotary motor of induction type in which the armature of the motor is enclosed in a casing formed of my improved material, the view representing a longitudinal section through a fragment of the. casing with the armature of the motor indicated by broken lines;

Fig. 6 is a cross sectional view taken on the line l--t ot' Fig. 5: and

Fig. T is a diagrammatic plan view of anothermodification of my material illustrating how a plurality of spots of high magnetic permeability may be formed with angularly disposed layers of fabric.

Referring to Fig. l, it will be observed that the fabric of which my material is composed has a warp of textile threads 10 displaced at intervals by metallic threads 11, while the weft threads 1;.' are all of textile material.

.As the object of this fabric is no-t to attain physical strength but magnetic permeability in defined regions the wires are preferably as fine as the textile threads. In practice it has been found inadvisable to use a. large number of wire strands in the warp wit-hout intei-posing occasionally one or more textile threads between the wires. Because of the smoothness and hardness of the metallic strands the matting action which is desirable in weaving is absent, and there is a tendency for the filling threads to slide out between the warp threads while shedding. In other words, after the weft threads have been beaten into the shed by the reed, there is a tendency for the filling to slide out during the shedding operation, that is, during the raising and lowering of alternate` warp strands. i This is prevented, however, by inioducing a thread of textile material between the wire warp threads. In practice it is found that desirable matting can be obtained if one or more threads of textile material be introduced between every four or five metallic threads. I therefore, form the warp with stripes of metallic wires interspersed with textile threads as shown at 13 in Fig. 1. It will be understood of course, that the' stripe of iron wire need not be confined to the number shown in the drawing but may extend over any desired width of the fabric provided warp threads of' textile material are introduced at sufiicientl frequent intervals to produce the desireclmatting of the fabric. Having produced the fabric shown in Fig. 1 the next step of my process is to impregnate the fabric with a phenolic condensation product, after which layers of fabric are arranged in a pile as shown in Fig. 2 with the stripesof metallic wire in superposed alined relation. The fabric may be arranged in a flat pile or may be Wound in a coil to form a solid rod or it may be wound around a form, if it be desired, to produce a cylindrical, rectangular or other form. The pile of fabric is then subjectedto pressure and heat and the condensation product fills the spaces between the textile threads and between the wires inseparably binding all parts together in a uniform hard substance in which wire is thoroughly embedded. The material is very strong and shows no tendency to cleavage between regions of high reluctance and low reluctance. The material is also water proof and gas proof and a good electrical insulator except where the wire provides a path for electric current and. because the wire strands are separated by the textile threads and the impregnating condensite product, a high resistance to electric current is offered, which tends in use to prevent the formation of eddy currents. At the same time the magnetic reluctance of the material is markedly lowered in the zones or regions traversed by the Wires.

As explained above one of the. principal uses for which this material is adapted is to be found in the art of refrigeration in which itis desirable to have a closed system sealed against gas leakage and in which mechanical work may be performed by means of energy transmitted from without the system,

avoiding any moving member passing into.

the system. Such au application was described in the aforesaid co-pending application and is illustrated in Fig. 4. lt comprises a pump employing a cylinder 16 formed of my improved material, having therein Zones 17 of low magnetic reluctance runningcireumferentially about the cylinder. The. cylinder is surrounded by field coilsA 18 located in comb-shaped yokes 19, the teeth of'whieh engage thc zones 17. Within the cylinder 16 is a pump plunger :2l carri/ul b v a vtio i the lines of magnetic flux passing between,

and tightly secured by means of wedges 26.'

Although condensite and bakelite are generally considered to be insoluble, I have found that they are not insoluble inl anhydrous am monia and hence, it is desirable to line the cylinder w1th some material, such for in l stance, as tin, which is not affected by am monia when my pump is to be used for pumping ammonia gas. Such a liner is indicated at 27 and as it is not required to have any great strength, because the cylinder itself is strong enough to resist any pressures developed by the pump, it may be made merely thick enough to prevent actual contact of any liquid ammonia with the bakelite or condensite surface. The liner may be applied to the cylinder electrolytically or in any other suitable manner and as its purpose is merely to rovide a .coating non-soluble in the fiuids handled by the pump it need not necessarily be of meta-l. But if a metal liner be used it should be non-magnetic so as not -to divert the yoke 19 and the armatures 23 ,through the zones 17. Because the material of which the cylinder is composed o'ers considerable reluctance to the passage of magnetic lines of force, an easier path for the flux is found through the zones 17 into and out of the armatures 23, and because of the thinness'of the liner 2.7 there is no' appreciable loss due to leakage of iux. It will be understood of course, that when the pump is to be used for pumping other gases or liquids which do not affect my improved material the liner 27 may be dispensed with.

While I have illustrated my improved-material as employed with a reciprocating pump, it will be evident that it can also be used with any solenoid or an straight line motor. Fig. 5 illustrates anot er application in which the material is employed in connection with a rtary motor. The ligure shows a cross sectional view of an induction motor with the armature removed but indicated by broken lines at 30. The field windings 31 and core 32 are separated from the armature by a casing 33 of my improved material in which bearings (one being indicated at 34) are provided for the armature shaft 35. A construction such as this can be used in refrigerating apparatus to provide rotary motion within a sealed casing transferring energy through the walls of the casing without any mechanical transmission of motion through the casing'. In this application of'my material, however, the regions of low magnetic reluctance must not run circumferentially` about the casing but must run parallel to the axis of the armature, otherwise there would be a magnetic short circuit between the field poles and little or'no magnetic flux would reach the armature. Instead the lines of lo'w magnetic reluctance run lengthwise-of the cylindrical casing 33 as indicated at 36. In building up a.

casing of this sort, itwill be evident that care ,m'ustbe exercised to arrange the layers of fabric so that'the wire stripes of the outer layers will be wider than those of the inner layers,A thus forming the sector shaped regions illustrated in the cross sectional view of Fig. 6. In forming the fabric it will be nece-ssary to compute the number-of wires required to effect this result. l In other words, the stripes of metal must be progressively wider across the width'of the fabric and must be separated bysuccessively wider stripes of non-metallic fabric as We proceed from the inner to the outer layers. It is possible to arrange the warp of the fabric with considerable accuracy so thatthe successive layers will fall one above the other as the fabric is Wound widthwise about a form. However, while it is desirable that the zones of low magnetic reluctance be de cessfuluse of m'y material.A For instance, there could be and in commercial practice doubtless would be, considerable irregularity along the margins of the zones, provided the principal object is maintained of producing a patlof much lower reluctance through the material into the armaturethan exists between successive fields of poles, so that by far a greater part of the magnetic energy will ypass into the armature instead of leaking across from one pole 'to` another. It will be ed transversely by radial lines, this resul isnot essential to the suc-v lll() noted that the thickness of the casing is much thickness but this material is machined down or otherwise reduced aloner the zones or re-` gionswhere the wire is embeddedyso as to reduce the thickness at these points as much as possible and thereby reduce the magnetic reluctance. At these points not-only is the material reinforced by thewire therein, but it is alsol reinforced by the pole pieces which bear against the wire zones, so that the cylinder is not materially weakened by/ such reduction of thickness. c

I have described the fabric of which my material is composed as having wire stripes running lengthwise or' in the warp material. In pcommercial practice it is simpler to Weave a frabric with wire strands in the warp rather than in the fwefts, but it would be possible and in certain'eases preferable to use wire-in the weft rather than in the warpl and hence I do`not limit myself to a fabric with wire warp strands.

I have referred to the fact that it is not esof thev of the next adjacent layer in building up my material. Indeed in some cases I find it desirable to offset the successive layers somewhat, so as to obtain the result shown in Fig. 3 wherein the paths of low reluctance through. the material, are inclined instead of being `normal to the plane of the material.

Another modication .is illustrated' diagrammatically in Fig. 7 which shows the wire stripes of a plurality of layers of fabric, the body of the fabric being omitted. Three layers of stripes 11', 112 and 113 are indicated, each layer forming an angle of 60 degrees with the other two. When the material is made up of layers so disposed there will be intersecting spots where the magnetic reluctance is but one third of that through other parts of the material traversed by the stripes. The material may be' built up of any number of layers thus angularly disposed and smaller angular displacements may be used to further reduce the relative reluctivity at isolated spots. In fact the layers may each be provided with a single stripe or even a single wire and the successive layers be assembled with a minute angular displacement about a common intersecting point, when the transverse path of low reluctivity at such point will have a relative reluctance value inversely proportional yto the number of the angles of displacement.

I claim:

1. A material for use in magnetic apparatus consisting of a solidified plastic substance having layers of textile fabric embedded therein, the fabric being formed with interwoven stripes of soft iron wire.

2. A material for use in magnetic apparatus consistingpf a series of fabric layers b ound together by a solidified phenolic condensation product, each layer including a -stripe of magnetizable strands woven into the fabric.

3. A material for use in magnetic apparatus consisting of a series of fabric layers bound together by4 a solidified phenolic condensation product, each layer including a stripe of highly para-magnetic metal woven into the fabric.

4. A material for use in magnetic apparatus consisting of a series of fabric layers bound together by a solidified phenolic condensation product, each layer including a stripe of soft iron wire Woven into the fabric.

5. A material for use in magnetic apparatus consistingr of a series of fabric layers` bound together by a solidified phenolitI condensation product, each layer including a stripe of low reluctance wire Woven into the fabric, the stripes being superposed and alined.

6. A material for use in magnetic apparatus consisting of a series of fabric layers bound together with a solidified phenolic condensation product, and each layer including.,r a stripe of lo` reluctance wire Woven into the fabric. the stripe of each layer being disposed in a pre-determined geometrlc relation to the stripes of adjacent layers.

7. A material for use in magnetic apparatus consisting of a series of fabric layers bound together by a solidified phenolic condensation product and each layer including a stripe of iron wire woven into the fabric, said stripes being disposed in superposed relation, and a protective coating von the surface of the material.

8. A material for use in magnetic apparatus consisting of a series of fabric layers bound together by a solidified phenolic condensation product and each layer including a stripe of iron wire woven into the fabric, said stripes being disposed in superposed relation, and a' non-magnetic metallic coating on the surface of the material.

9. A cylinder for use in a magnetic apparatus consisting of a length of fabric having a stripe of iron wire woven therein, the fabric being spirally wound to form a coil and the whole being bound together by a solidified phenolic condensation product.

10. A cylinder for use in magnetic apparatus consisting of a hollow cylindrical coil of fabric bound by a solidified phenolic condensation product, the fabric including a circumferentially disposed stripe of iron woven into the fabric.

11. A cylinder for use in amagnetic apparatus consisting of a length of fabric having a stripe of iron wire woven therein, the fabric being spirally Wound to form a hollow cylindrical coil and the whole being bound together by a solidified phenolic condensation product, and a protective coating on the inner surface of the cylinder.

12. The process of making material for magnetic apparatus which consists in weaving a fabric of textile material With stripes of metal threads interwoven therein, impregnating the fabric with a phenolic condensation product, arranging the vfabric in layers with the stripes in superposed and alined relation, and subjecting the whole to heat and pressure.

1E. The process of making material for magnetic apparatus which consists in impregnating textile fabric with a phenolic condensationproduct, the fabric having stripes of metal interwoven therein, arranging the fabriclin layers with the stripes of each layer disposed in a pre-determined geometric relation to the stripes of adjacent layers, and subjecting the Whole to heat and pressure to solidify the phenolic condensation product.

14. The process of making material for magnetic apparatus which consists in impregnating textile fabric having stripes 0f metal interwoven therein, with a phenolic condensation product, arranging the fabric 1n layers with the stripes of the several layers dlsposed to superposed and alined relallU Laenge tion, and subjecting .the wholev to heat and pressure.

15. The process of making material for 'magnetic apparatus whichconsists in im 5 pre ating with a phenolic condensation pro uct a textile fabric having stripes of metal interwoven therein, winding the fabric about a form with the stripes of metal in the several coils of the winding disposed in superv posed and alined relation, and subjecting-the.

whole to heat and pressure.'

v16. A material for use in magnetic apparatus yconsisting of a solidified plastic substance having layers- 'of textile fabric embedded therein, the fabric being formed with .inter- 'v voven stripes of magnetizable material.V

LOUIS H. ROLLER. 1

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