Патент USA US2412254код для вставки
Déc. 10, 1946. 2,412,254 w. 5. EDELMAN ,MOTOR Filed March 27, 1942 87 so 52 :3 s INVENTOR Walter E. Eda Lman BYM 941M, ATTORNEY Patented Dec, 10, 1946 2,412,254 Ul‘tlTED STATES T FFICE 2,412,254 MOTGR Walter E. Edelman, Minneapolis, Mil’lEL, assignor to Minneapolis-Honeywell Regulator Company, ‘Minneapolis, Minn, a corporation of Delaware Application March 27.. E942, Serial No. liddgioii l2 no Ulla a ll éa ‘1 _'l‘his invention relates to the motor art but more particularly to improvements in the con structlon and arrangements of parts in electri cal motors providing greater e?'iciency in oper ation, promoting increased economy of construc tion, facilitating assembly and increasing the ac-’ cessibility of parts for purposes of replacement and repair. The present invention is concerned primarily with improvements in relatively small motors, but it will be understood that the fea tures are not limited thereto and may be applied to motors of other sizes as well. A broad object of this invention is vthe provi sion of a comparatively small motor which is unusually powerful in proportion to its size. Another object of this invention is to provide a comparatively powerful motor in proportion to its size by utilizing the necessary iron and copper in advantageous proportions. A further object of this invention is to provide a motor having an advantageous copper to iron. ratio by utilizing all available space for winding purposes. _ > Another object of this invention is to provide a stator comprising a plurality of laminated sec= tions each having wound thereon a substantially cone~shapeclwinding the sides of which. are sub stantially coincident with its adjacent windings. associated parts as removed from the rest oi the device, Figure 5 is an enlarged fragmentary view of a portion of the stator vand casing, Figure 6 is an enlarged face view of a stator. section, and Figure “I is a perspective view of parts of the fabricated bobbin. Referring to Figure l, the numeral it generally indicates a motor operator which is illustrated approximately to actual size. The motor oper ator is is housed by a pair of telescoping casing members if! and 62, the casing member i2 com prising a cover and having anannular ?ange it which is telescopingly received into the casing member ii. The numeral M generally designates a stator, to be described in detail hereinafter, which is located in the main casing member ii. A rotor ‘55 cooperates with the stator it and is operatively secured to a shaft iii which is ro tatively supported in a pair of bearings ill and ill carried by and concentrically disposed with respect to the casing members it and t2 respec~ tiveiy. rl‘he bearings ii and is will be described in greater detail hereinafter. Therotor shaft it) drives an operator shaft is through a gear train, generally indicated by the numeral It will be noted that though the rotor 55 is sup pd'ted by separate inter?tting members it and Another object of this invention is to provide 30 ii, the proper alignment of shaft l is assured by virtue of the telescoping arrangement of the casing members it and i2. Since the novel fea tures of the motor operator ill pertain primarily to the novel structure of the stator ill, and the novel means for retaining the stator sections in assembled relation. 1%. iurther object of this invention is to provide novel bobbin which is fabricated upon the stacked laminae COmprlSing a stator section in such a manner as to permit a winding to be wound thereon. - Other objects relate to novel means for lubri cating the motor shaft and gear train driven thereby, novel bearing construction, novel con struction assuring proper bearing alignment, and novel motor housing construction. Still other objects are those'not speci?cally re citei hereinabove which will become apparent or implied from a reading of the speci?cation, ref; erence being had to the accompanying drawing in which ' ‘ novel manner which it is mounted in the casing . it is thought expedient to first describe the stator construction and mounting in detail after which the other novel features of the motor oper ator which are incidents thereof will be similarly disposed of. Referring to Figure 5, it will be seen that the stator it comprises a plurality of identical inter loclrable sections‘lii. Each section comprises a plurality of larninations (see Figures 1 and 6) which are held in stacked relation by a field winding which is wound directly on each sec~ tion Each section 2i has an arcuate yolre Figure 1 is a section of the device through the rotor shaft as viewed along the line i—-i of portion which conforms with the inner cylin drical surface of the casing‘mernber it, a pole Figure 2, > 50 face portion which is concentrically ‘formed Figure 2 is a. face view of the device with the with respect to the casing ii, and a pole portion. cover and rotor removed, 2E radially disposed with respect to the casing i i. Figure 3 is a face View of the terminal block as viewed along the line 3-3 of Figure 1, Figure 4 is an inside face View of the cover and Each yoke pole portion portion is25extended carries ato?eld eachwinding side of the mole portion, the extension on one side having a 2,419,254 , 3 ‘ r tongue 2? and a groove 28 and the extension on the other-side having a tongue 2b which engages 4 ?rst pair of insulation pieces 38, 32 as indicated .by the dotted lines in Figure 6. The bobbin . the tongue and groove of the adjacent section. pieces 33, 3d are substantially H-shaped, each The arrangement of the tongue 2i, groove 28, and having outer and inner doubled-back portions 35, 36 and 31, 38 respectively, which cooperatively comprise the outer and inner ?ange portions of the bobbin. The doubled-back portions 35, 36 of tongue 29 of each section is such that when the sections 2| are assembled and a circumferential pressure is applied as by an annular ring, band, or, as in the illustrative case, the casing ii, the reactions between the tongue 21, groove ‘28, and tongue 23 rigidly hold the‘ pole face portions 25 in circumferentially spaced relation. In practice, , the bobbin piece 33 comprise upper and lower extensions 39 and fit which extend transversely ‘above and below the pole portion 25. Likewise the doubled-back portions 37, 38 have extensions Iii and M which extend transversely above and below the pole portion 26 in overlapping relation sure is applied by means not shown, and the with‘ respect to the extensions 39 and 40. The stator M is then pressed as a unit into the casing i i. It should be pointed out that the interfitting 15 flange portions 35, 36 and 37, 38 may be regarded as the vertical bars of the H-shaped bobbin pieces relation of the sections provides a low reluctance the sections are assembled, a circumferential pres magnetic path in the yoke of the stator, and the 33, 36, and the portions thereof adjacent the sides cross section of the yoke may be a minimum consistent with good engineering practice since the need for holes for receiving rivets, bolts or of the section 2! may be considered the cross the like, is obviated. Accordingly, the resultant overlapped in such a. manner as to prevent a reduction in the amount of iron necessary in the stator makes available a greater space for wind catching of the winding 23 on the extensions in the process of winding it in the bobbin 3. In practice, each section 2! is fabricated by. first stacking the laminations 22. The insulation pieces 3! and 32 are then placed on the top and bottom of the stack respectively. The bobbin ‘ ing' purposes. Consequently, by obtaining a greater proportion of copper to iron, a more com pact and smaller motor may beobtained which \ is comparatively more powerful in proportion to , bars of the H-pieces. As will 'be pointed out hereinafter, the extensions 39, at and 5!, 1:12 are its size. pieces as, 3% are then placed adjacent the sides It will be seen in Figure .5 that each pole face of the pole portion 26 between the lateral exten portion 25 is of a maximum width nearly touch 30 sions of the yoke and pole face portions. The ing its adjacent pole face portions. The width upper extensions iii , d2 of'the bobbin piece 36 are of each pole face portion 25, therefore, is deter placed inwardly of the upper extensions 39, it of mined by a central an‘glewhich is a function of the bobbin piece 33. Likewise the lower exten sions 39, iii! of the bobbin 33 are placed inwardly the number of poles. Since all-of the sections 2! are identical it naturally “follows that the width 35 of the lower extensions iii, d2 of the bobbin piece of each yoke portion 2a is likewise determined by the same central angle. In the illustrative case, the stator it has 8 physical poles and ac cordingly the dimensions of each section 2! are 343. Thus, by the overlapping arrangement of the material such as gray ?bre. :39 extends adjacent to a terminal 41 on the ad extensions, as clearly seen in Figure 5, it is pos— sible to wind the winding 23 in vthe direction of arrow 63 without the windingbeing caught on determined by a central angle of 45° as shown in so the extensions. It will be noted that the faces v(iii of the yoke portion extensions are formed nor Figure 5. It will‘ be further noted that the cross mally with respect to theirlpole portion 25 to sup section of the pole portion 26 is considerably less port the doubled-back portions 35, 31 of the bob thanithe cross section of its pole face portion 25. bin pieces 33, st normally of the pole portion 26. While this arrangement precludes the use of a Likewise the insulation pieces Si, 32 have nor. preformed ?eld winding 23, it has the advantage mally extended surfaces 65 for supporting the of making available a greater space for the wind doubled-back portions 3, 38 of the bobbin pieces ing without objectionably increasing the-reluct 33, 3d normally of the pole portion 26. Thus, each ance of the magnetic path in. the pole portion. section 2i may be rotated‘about the axis of its Each winding 23 is formed substantially cone shaped, being wound to‘such dimensions as to so pole portion 26 and the winding 23 wound in'the bobbin 30 by a simple winding process without be substantially included ‘in the central angle the need of a complicated guide means. To hold hereinabove referred to. Accordingly, each side of each winding 23 is substantially coincident with each bobbin 3 in assembled condition before the winding. process is begun, a single layer of the side' of the adjacent winding thereby utiliz ing practically all of the available ‘space occupied 55 tape fit is wound about the pole portion 25. The .section is then mounted in a suitable winding jig, by the stator except such space as ,is necessary to not shown, and the winding wound directly in prevent a short circuiting between windings. As the bobbin forming the cone-shape‘ referred .to a matter of fact, when the stator is viewed-from hereinabove. The ends of the windings are then . one side, as in Figure 2, there is substantially no secured to inner and outer terminal pieces d7, 48 air space between the windings. ’ secured to the upper extensions 39, Ml of bobbin To properly insulate each winding 23 from its piece 33, as best seen in Figures 5 and 6. The section 2! as well as to properly con?ne the‘same winding 23 is then coated with a suitable seal to its cone-shape thereon, a bobbin 3% is fabri ing compound such as glass cement or varnish cated about the pole portion 26 of each section 2!. Each bobbin 3!! comprises a ?rst pair of 65 to hold the winding turns of greater radii from insulation pieces 3!, 32 which may be formed of slipping down over the turns of lesser radii. The sections 2! are then assembled as previously de any suitable material such as Bakelite. Pieces - 3 I, 32 are shaped similarly to the section lamina scribed, and inserted as a unit into the casing member ii‘, To prevent the inner terminals Ill tions 22 ,and are disposed at the top and bottom respectively of each section 2!. Each bobbin 30 70 from moving inwardly'and short circuiting each other, a flag i9 is provided on the doubled-back further comprises a second pair of. insulation portion 383 of each bobbin piece 34. Each ?ag _ pieces 33, 34 which may be formed of any suitable Pieces 33, 3d are disposed adjacent the sides of each pole portion jacent section 2! as best shown in Figure 5. To 26 in overlapping relation with respect to the 78 prevent the outer terminals 41 from moving out 2,412,255 5 wardly and engaging the casing ll, a-ring 5G is placed around them. The ring 50 may be formed 6 The bearing ll is supported in a hub 86 which is extended inwardly of the casing ii to reduce of a. strip of gray fiber the ends or’ which are interlocked as seen in Figure 2. the overall length of the motor operator it as well as to utilize the space between the rotor l5 The stator i4 is held in position in the casing GI and the casing end wall resulting from the ex H by a pair of retaining means in the form oi’ a tension of the coil 23 to each side of the stator shoulder 56 formed in the casing ii and a split it. The hub is spaced somewhat from the ring 52 which is received in an annular groove closed end of the casing ii and is integrally con. 53, also formed in the casing l i'; The ring 52 has In prac 'nected therewith by an arcuate web turned up ends to by means of which the ring 10 tice, the casing it is ?rst received in the form may be removed from the groove and the stator of a rough casting in which the hub projects it removed from the casing for such purposes as directly from the closed end of the casing, the repairing or replacing the stator section it. Dne hub till and web 55 appearing as indicated by or more rings 55 of resilient material such as cork the full lines in Figure 2. The bearing support or any other suitable compressible material are 15 is formed by first boring the aperture in which inserted between the stator id and the retaining the hearing it? is received concentrically with re means The rings ful?ll a dual pur spect to the casing ii. The aperture is then pose, serving to talte up the variations in the counter-bored until the arcuate web is formed .thicltness of the stators resulting from the and an opening is provided between the hub 53!} variations in. the thickness of the laminations and the closed end of the casing ii. The casing E22, and also serving to absorb somewhat the mag ‘ii is then further counter-bored and a plug 65 netic vibrations set up in the stator ill, is inserted therein to again close the casing. As shown in Figure 2, the windilgs 2 are con Bearing ii’ is lubricated by an oil conductive nected to provide a split phase induoti .otor means which may be in the form of a felt pad arrangement in ‘which the tour lead w which is disposed adjacent to the closed end brought out to a terminal blocli The tm iinal of the casing it and has a portion which ex block till has a hub portion which is i t a in a circular aperture 5.; formed in the casing member connected matter are bared ofit. for fact, to The the a length inwires lead actual corresponding wires practice, of a cable arethe to el tends The pad. between 6i extends the hearing into theitoiland which the isplug main 1" islead 38 ' wires 56 and extended through apertures ‘35? pro vided in the terminal block. The apertures 62 are then ?lled with solder, thereby providing an oil ed approximately at a level as shown in Fig l. The bearing accordingly, is lubricated use capillary bearingaction is supported of the oil in by the a ?ange pad 89 pro tight connection with respect to the casing i i.‘ vided the p-orted casing The bored lead wires 5"‘? are covered with suitable screws suit a plate ll? which is tclescopingly received casing member it. The plate it is sup on posts 'Jl integrally formed with the member 42 and secured to the. posts by The gear train is rotatively able insulating material such as synthetic rub~ supported between the plate and the casing “oer, which is not subject to deterioration by the member the operator shaft it being rotatively action of the oil which is maintained in the mo 40 supported in a bearing l3 staked to the plate ‘ill tor operator housing for purposes of lubrication and a bearing conveniently supported in the as will hereinafter appear. A washer (see casing member it. A gear ‘l5 operatively secured Figure l) of suitable insulation material such as to the shaft is is driven by a dual gear ‘it which gray fiber is placed between the casing member in turn is driven by a second dual gear ill. The i2 and the terminals iii and to insulate them 45. gear ll is driven by a pinion it which is oper from the casing 52. atively secured to the motor shaft iii. It is ob ‘Having fully described the stator in including vious that because of the arrangement of the the details of its construction, fabrication, and inountinr‘ with respect to the casing member ‘l i; the rotor will now be described in detail in“ 50 movable as a unit from the casing nie iber it. cluding the manner in which it is rotatively sup ported so as to cooperate eiiiciently with the stator‘ ill, the manner in which it shares a com~ more support with the gear train so as to pro vide a proper driving connection therewith, and the manner in which the gear train and rotative support for the rotor are lubricated, In. the foregoing description of the stator ill have it hasbeen been rigidly seen how spaced the pole circumferen faced portions it concentrically with respect to the casing member it without the use of rivets, bolts,' or "1 e like holding means, and without the need of lnachin= ing the pole faces ‘to assure their concentricity. Since the rotor it is of the squirrel cage induc tion type, the importance of the proper align rnent of the stator M and rotor it will be ap preciatecl inasmuch as a smaller air gap made possible resulting in greater e'fdciency. It will now be seen how the bearings it for the rotor shaft to are supported so as to assure the concentricity of the rotor with respect to the casing member i 5 thereby providing enlcient cooperation between the rotor it and the stator it. pinion ‘iii and rotor it on opposite sides of the plate the rotor and easing member 92 are re Consequently, the driving connection between the rotor iii and the gear train is not dis turbed by such a removal. 'Furthermore, the removal of the rotor renders the stator more ac‘iessible for purposes of inspection and repair. The dual gears ‘is, ‘it’ are mounted for rotation on. pins l3 Elli respectively which are staked to which plate formed and received in the casing into member sockets ti and From the foregoing, it is obvious that the concentricity of soaring i=3 with_ respect to the casing member ii is assured by the telescoping relation of the plate with respect to the casing member it which in turn is telescopingly ?tted with respect to the casing member it. Moreover, the proper meshing relation of the gears of the gear train is assured by virtue of the telescoping ar raneernent of the plate "ill with respect to the casing rnember iii and the provision of the soclo ets iii, for receiving the pins l9, 8d respec tively. \ The lubrication of shafts iii and id in bearings it and ‘i3, respectively, and lubrication of dual gears ‘i6 and l'] on pins ‘iii and 85) respectively, is provided by an oil conductive means which aaraast 7 & . overlapping and insulating the terminal piece may be in the form of a felt pad 83 which is dis carried by the adjacent bobbin side portion. posed adjacent to the plate 10. The pad 83 is 4. In a motor, a pair of telescoping casing‘ arranged to surround the pins 79, 89, the shaft 16, and the bearing 13 are lubricated by the capil members, a, stator in a ?rst of said members, a lary- action of the oil in the pad 83. As in the Cl rotor for cooperation. with said stator, a. shaft for said rotor, a plate telescopingly received in the case of pad 67, the pad 83 also extends below second of said members and secured thereto, said the level of the oil as best seen in Figure 1. It shaft being journalled in said plate and said ?rst will be noted that the gear train 20 also extends casing member, and a gear train journalled be ‘somewhat below the, level of the oil. Conse quently the oil is further distributed to the gear 10 tween said secondmember and said plate in driv able relation with respect to said shaft, said rotor train parts by means of a “splashing action” being removable from said ?rst member together which results from the rotation of the gears, with said second member whereby said rotor and Oil is admitted into the motor operator hous gear‘train are removable as a unit. , ing through suitable removable plugs 85! which 5. A motor operator comprising a pair of tele are conveniently provided in the casing member scoping casing members, a bearing concentrically l2 as best seen in Figure 4. The plate 70 is pro supported by each member in axially spaced re vided with four indentations 85 which permit the lation with respect to the end portion thereof, oil to reach the felt pad 6?. Accordingly, the oil conductive means for_lubricating said bear motor operator‘ it] may be placed in any one of ings and disposed between each said bearing and four positions without interfering with the proper the end portion of its respective supporting mem lubrication of the operating parts. ' ber, a rotor journalled in said bearings, a gear Each casing member is provided with four 00- . train driven by said rotor and journalled in one operating apertured ears 86 by means of which the casin'g members may be assembled in any one of four positions with respect to each other, of said casing members, said geartrain being lubricated by the oil conductive means in said one of said casing members, and a stator for co thereby providing four diiferent positions of the operating shaft 16 with respect to a particular mounting of the casing member H. Suitable bolts and screws 81 may be used to secure the casing members together. _ operation with said rotor, said stator comprising a plurality of interlockable sections insertable as a unit in the other of said casing members in 30 concentric alignment with respect to the rotor, and retaining means for providing axial align; ment of said stator with respectto said rotor. 6. A multi-polar motor stator comprising a plu From the foregoing it is now apparent that I have provided a compact motor which necessarily is comparatively powerful in proportion to its size since all available space has been utilized rality of circumferentially related stator sections, 35 each section comprising a radial pole portion, a‘ bobbin supported thereon,‘ a winding on said bob vantageous ratio of copper to iron. Moreover, 'the motor may be economically produced. and ' bin, said bobbin having a central portion for en for winding purposes, thereby providing an ad eiilciently operated in practice‘ because of the novel construction, fabrication, and arrangement of parts. _ closing said pole portion and inner and outer side portions for con?ning said winding, said wind 40 It is to be understood that the disclosure of the present invention is illustrative only and not to be considered in a limiting sense, since I con template all such changes, variations, adapta tions, additions, and omissions, which naturally fall within the inventive concept of this inven tion as defined by the appended claims. I claim as my invention‘: 1. In a multipolar stator, a stator section‘ com prising a radial pole portion of uniform cross section, a yoke portion extended normally tov each side of said pole portion, and a pole face por~ . ing being cone-shaped,dimensions of said winding and said inner and outer side portions of said ‘ bobbin being determined by a central angle which is a function of the number of the poles, and terminal pieces carried by said inner‘ and outer bobbin side portions for electrical connec tion with said winding, 9, further portion of one of said inner side portions of each of said bob bins bearing a member projecting laterally, whereby to inwardly overlie said terminal piece carried by said inner side of an adjacent bobbin, and insulated means surrounding said stator and outwardly overlying said terminal pieces carried by said‘outer sides of said bobbins. . tion extended to each side of said pole portion, '7. A multi-polar motor stator comprising a ‘said extension of said yoke and pole face por 55 plurality of circumferentially related stator sec tions being determined by a central angle which tions, each section comprising a radial pole por is a function of the number of poles. v tion, a bobbin supported thereon, a winding on 2. In a multipolar stator, a stator section'com vsaid bobbin, said bobbin having a. central por prising a radial pole portion, yoke and pole face tion for enclosing said pole portion and inner portions extended to each side of said pole por 60 and outer side portions for con?ning said wind-' 'tion, and a bobbin comprising a central portion: ing, said winding being cone-shaped, dimensions for enclosing said pole portion and inner and of said winding and said inner and outer side por outer side portions disposed adjacent said pole tions of said bobbin being determined by a cen face portions and yoke portions respectively, said tra1 angle which is a function of the numberof bobbin side portions'and said yoke and pole face 65 the poles, and terminal pieces carried by said portions being limited by a central angle which inner and outer bobbin side portions for elec is a function of the number of poles.' trical connectionwith said winding, 9. further 3. In a multi-polar stator, a radial pole por portion of- one of said inner side portions of each tion, a bobbin supported thereon, a, winding on of said bobbins bearing a member projecting said bobbin, said bobbin having a central portion _ for enclosing said ‘pole portion and inner and outer side portions for con?ning said winding, terminal pieces carried by said side portions for connections. with said windings, and a lateral 1 extension on one of said inner side portions for laterally, whereby to inwardly overlie said ter minal piececarried by said inner side of an ad- _' jacent bobbin. - 4 v 8. A'multi-polar motor stator comprising a plurality of circumferentially related stator sec tions, each section comprisinga radial pole por 2,4123% 9 11. A mu1ti=polar motor stator comprising a. tion, a bobbin supported thereon, e winding on said bobbin. said bobbin having a central p0r~ plurality of identical, ciroumiferentieliy adjacent sections each having a redial pole portion, an tion for enclosing said pole portion and inner and outer side portions for con?ning said wind ing, said winding being cone-shaped, dimensions enlarged pole face portion extending to each side of said pole portion and e yoke portion extend mg to each side of said pole portion, each yoke portion being formed to interlock with adjacent yoke portions and including an inwardly ‘facing pleine surfeee extending to each side of said poie of the poles, terminal pieces carried by said in ner and outer bobbin side portions for electrical iii portion and perpendicular to the axis thereof, no part of sold yoke portion extending beyond connection with said winding, and insulated said surfeee in the diseotion oi.’ enlarged means’ surrounding said stator end outwardly poie face, the ones of said pole portions being’ overlying said terminal pieces carried by said of saidwinding and said inner and outer side portions of said bobbin being‘ determined by a central angle which is a function oi’ the number outer sides of said boioioios. 9. in 2. motor, e stator, e rotor for cooperat direoted toward as common point, and said em 15% tensions of solid yoke and ooie iece portions of ing therewith, o shaft for said rotor, side wells eooii of said sections being determined e thebyout= and end walls comprising a poi? of cosine7 mem» ' one-"lo line of bers housing said stator and said rotor, bearing supports carried by said members and disposed in eisieiiy spaced reietiozisi'iip therewith for so» tota’siy supporting said shaft, with said goiene some to i'eeeive winding surrounding said looie Emotion‘ interme~ diary between said members and said suionorts, at least one of said moons being int-semi with and overlying a portion of the reieted member, and oii conducting means ieetweeo said support is y 1 and said member and extending to seid side s‘ie' ~ weiis of said mem‘oer L, tiiroiig'i'i said support for i'oiisi with said oii eondizetine means. In as motor o sotor so? for rotation in said casing", s rote-r, iobrieotino s 'rotor shell, ooinorisiog’ "iie silo-it, ' for silent, said end tiiioogii said means; at its 1? solid end oi i’ori I soid sin-ft for: mu Certi?cate of Correction Patent No. 2,412,254. December 10, 1946. WALTER E. EDELMAN It is hereby certi?ed that errors appear in the printed speci?cations of the above numbered patent requiring correction as follows: Column 7, line 4, after “bearing 73” insert which; column 9, line 30, claim 10, for the Words “motor casing” read motor, a casing; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent O?ice. Signed and sealed this 9th day of November, A. D. 1948. [SEAL] THOMAS F. MURPHY, Assistant Commissioner 0 f Pa'temfs. Certi?cate of Correction Patent No. 2,412,254. ' December 10, 1946. WALTER E. EDELMAN It is hereby certi?ed that errors appear in the printed speci?cations of the above numbered patent requiring correction as follows: Column 7, line 4, after “bearing 73” insert which; column 9, line 30, claim 10, for the Words “motor casing” read motor, a casing; and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent O?ice. Signed and sealed this 9th day of November, A. D. 1948. [SEAL] THOMAS F. MURPHY, Assistant Commissioner of Pa'tents.