US2672824A - Hydraulic pump or motor - Google Patents

Description

March 23, 1954 B. F. QUlNT lLlAN 2,572,824

HYDRAULIC PUMP OR MOTOR Filed May 11, 1944 Patented Mar. 23, 1954 i UNITED PA- 1 E mmmumro PUMP art-Moron Bart-liolom'ew Frank Quintil ifanf; Baltifiiore'j assignon to-Gerotor May corporatioh ai rat'ioniolcMa-ryland Application May 11, 1944:, ser al No} 535389; 1 9 fllaim st- (CL -1OS- I 2G onion My invention relates to rotary hydraulic charge'wthis swa m the fairsidejand' brought pumps and" motors-in" whichrotatableelements about an increase in pressure iriafiuidre'ceiving provide a pluralityof fluid compartments ofconreservoir,j from which the fiuid could be ejected tinuously;varyingdimensions: through a" discharge orifice; opening as when An object of'my invention-ism provide 'a re- 5 the interior pries'surereachedi a predetermined tarypumpwhichrissimple;smal1;1compact; rug,- value; Such pum mad marr advantages, pringed; inexpensive and haslongglife and lowwear cipal amongi whichfwere l'ong" Wear" and sim even under" conditions," of continuous use, has plicity'. V V U both highvolumetrici and high mechanical effl- From this relatively 'ciude piitrip of compara ciency, has" smoothand uniform f1c w,1uaquires "tively'low'capaeity gbut "which" nevertheless reminimum maintenance, supervision and repair, ceive d"wide=snreadi acceptance" in the induse has:onlya-minimum-numben ofmoving'parts all tries=-the"art quicklydevelo'ped tothepoint of of which are readily interchangeable; has low providing a construction which h'a'da plurality relative rotationahspeedIdetweentl'iecomponent ofEseparate compressor" compartments defined partsg and which requiree-not-speed reducers:- between compIehientaPparts ofinneran'douter Other objects Wi'1'];" in part be obvious and in pumprotors: These compartments" operated part-pointed" out-hereinafter; in connection with separately as 'pumpi-ngi. compartments; By propthe following description taken mthe light of er choice ofthenuiiiher anddin ensions' of the the appended-claims? compartments the" total capacity" of the? unit Accordingly,"my in-vention'consists ofithevarlcould-hefiriciteased many'timesover that" of the ous* parts; elements; combination of parts'end 01dcompartmentftype 'of pump. This actionwas features of 1 construction; and in-the relation 1*of basecffundamentallyiontthe relative rotation oceach of thesameto one orf more' of "the others -as curring between the inner and: outer rotors as a described herein and"- 'setr-foi th' in the following result of having teetlr'of the inner" rotor one" less claims? innumberthan corresponding" teeth and ratios- In the attached drawingswwherein is shown seem-the arameter? Aftypidal' instance offthi's solely byway of illii'strationfand not inan'ysense construction is'fshotzfiiorfexainple in" theUnited by way 'of limitation; "a preferredembodiment-of stateypatenr to Hill, :N 01' 2,011,333." The outer my inventiong rotors in"= these""earlierf'devices tookth {form of Figure 1'disol'oses myineW pump ifr" perspec p1ats--'or* discs?circulann'fouterperiphery'but tivegm annularly' toothiedg so asttouorrr'i 'a pluralityfof Figure--2 is=an= exploded perspective viewof-the inwardly proj eating-rounded teeth with interpump; showing 'certaiir of the elrnents tl'fereof veiling-valley orconcave"portions;

in theirrelatiom to each other, the pump casing Withthis outer rotorconst1"uction and with being: in axial sectioir, for clarityt" teeth of *the inner" rotor enga ged' about its Figure- 3 is v a fragmentary' exploded perspec periphery, then-'upowmrafidn of one of therotive view showing themanner in whioh' the roi tors to drive the other, ajoonstantbut slowgain lers 1 are assembled in the cor-respondiiiig end in -revolutions occurred betweenthe two rotors. plates: to for-m aicage like outer rotor; whil'e v The teeth of the inner iirotor remained-t at i all Figures 4- and 5 are elevations-showing the 40 times in-contact with the out'er rotor and thus pumpri assembly in 'difl'erent ph'ases' of c'the--same definewa plurality of *com'parttnents "of continuoperating-rcycle; to =-faoilitate ready understandl ously fy fi fi fi With-"pr per e ingLOf' theamod t fizopemtinnpw these 'oompartxrientsweresealed against the ex To ensureithorough appreciation of themature ter-ior- 'so that whrf *aiflu'id such as "air or liquid and extent I of; certain? afeatures oftjmy invention wasintroducd' through?asuitable port into the consideration may beigiven briefiy at this point compartmentsatapoinfi where these latter had to: thea-developmene of hydraulic: equipment of approximately theirgreat'stdimensions; then the gen'eralnnature of 1 that 'di'scl'osed" herein? subsequent -phases of any particular revolution Ataniearly dateut wasappreciated that rotary of the drivingrotor-fthe severalT compartments pumping" could be achieved b y rolling two gen de reased-in dimensions? to: a" minimum; th erany vcylindpicglr'm'embers such asxgears:agaihsfi compressingthefliiiwcontained' therein. A suit each other within wsuitable casingy" From a able=-port-wasprovidedfadjacentthe region of suitableintake reservoir, wfluidwassupplied-"the minimum-dirhension's' through, which the comtwo:members on"the forwarcl side in the difee prssew-nuiowas discharged. tion of rotation. The two rotating memlbrs dis '65 Needlesswary 'imsravea pumts of this ty'iae have received widespread acceptance in the art.

They are compact, simple and due to the small number of moving parts, display long wear and require but little maintenance, repair, and supervision. Properly designed, hydrostatic balance is experienced, so that to a certain extent at least a sort of floating action is occasioned between the moving parts of the construction.

Despite the manifest advantages of the construction just described, however, it will be noted that the contact between the cooperating parts of the inner and outer rotors is frictional and sliding in nature. Particularly when the fluid is being compressed as a gas undue wear between the contacting parts is experienced, probably due to insuflicient lubrication, so that readjustmentthe outer rotors.

An important object of my inventiontherefore is toprovide a construction which in substantial measure eliminates the aforementioned disadvantages and defects, and which at the same time is characterized by the production of rolling, anti-friction contact between the moving parts, to the substantial exclusion of frictional or sliding contact, and by its extremely long life and low wear under substantially all conditions of usage and when handling substantially all types of fluids.

Referring now more particularly to a preferred embodiment of my invention, in Figures 1 and 2 there is shown a rotary pump having an outer body portion I0, illustratively cylindrical in form, and having an inner cylindrical recess or bore indicated generally at I I, terminating at its inner end in a machined wall IIa which for example is a plane surface perpendicular to the axis of the bore. A cover plate or head I2 in the form of a circular disc seals the open end of the bore II in any suitable manner as by bolts I3 which extend through washers I3a and holes I I in the head I2 and seat in corresponding threaded apertures I5 in the adjacent end of the body member I0. Preferably holes I4 are shouldered to receive the washers I3a. Dowel pin I2a is provided on the inner face of head I2 and is recally assuring ready and proper positioning of the head I2 relative to the body I during the process of assembling the several parts. The body I0 and head I2 together comprise the casing of my new constructions.

Ports IE, IT, generally circular in cross-section, are disposed on diametrically opposite sides of body I0, and extend from the exterior through and into the bore II. At the inner ends the ports I6, I1 terminate in corresponding manifolds I8, I9, relatively shallow but extending from the ports for a substantial distance in each direction away from the ports along the walls of the bore I I. In the embodiment undergoing description these manifolds extend approximately 60 degrees in each direction from the ports, each for a total extent of approximately 120, degrees of the circular extent of the bore. The utility of these manifolds will be developed hereinafter.

I provide an outer rotor (see also Figs. 4: and 5) which snugly fits within the casing defined by body Ill and head I2, and which includes a plurality of elongated rollers 24 that bridgethe 'is the same in each end-plate.

manifolds l8 and I9 and roll on the bore surface II. This outer rotor, in the form of a cage now to be described, is received in sealed relation against cooperating machined surfaces of the bore II and the head I2.

The cage, or outer rotor, comprises paired, like circular end-plates 20, 2|, having diameter somewhatsmaller than the smallest diameter of bore I I. End plate 20 is received snugly against the machined inner wall Ila of bore while end plate 2| is received snugly against the machined inner wall of head I2. A plurality of preferably uniformly spaced openings 22 are provided in each end-plate 20, 2|, disposed with their centers lying in a circle struck from the center of each end plate. The number of holes 22, and their position relative to adjacent holes, Preferably the end-plates are struck from the same die so that the positions of the holes in one end plate will be identical with those in the other. These holes 22 serves as journal bearings for studs 23, which extend between and are carried by the endplates. Rollers 24 of substantial radius extend for rolling contact slightly beyond the outer edges of plates 20 and 2|. The rollers are axially bored in whole or in part and are mounted for rotation on the studs 23 or are made with bore omitted so as to have integral axial studs at the ends thereof. These rollers preferably are formed of case-hardened metal, ground to size. They are comparatively simple and inexpensive to produce and inherently have extremely long life. Wear is reduced to a minimum.

The cage comprising the outer rotor is thus seen to consist of the end plates 20, 2| which are held separate along the length of the bore by the rollers 24 disposed onthe studs 23. It has already been stated that the fit between the end plates 20, 2| and the corresponding walls of the body In and head I2 is as snug as can be achieved, consistent with the rotation of the cage relative to the casing. The purpose of this, as was explained, is to insure a seal between these parts. To contribute to this sealed relation, the rollers 23 are dimensioned so that they fit snugly against the inner surfaces of end plates 20, 2| and roll firmly on bore II. Reliance is placed upon an oil film of microscopic thickness to lubricate the rollers and to permit them to rotate on their studs 20 without disturbing or breaking the inner rotor seal which will later be described.

An inner rotor, movable relative to the outer rotor, is disposed within the outer rotor cage. It is toothed in such manner that it has the general appearance of a fluted star wheel. This inner rotor is indicated generally at 25.

Both the end plates 20, 2| of the outer rotor and the inner rotor 25 are disposed on a drive shaft 26. End plates 20, 2| are disposed comparatively loosely thereon so that shaft 26 imparts no direct rotational impetus thereto.

Inner rotor 25, however, is disposed on shaft 26 and is made fast thereto. Rotor 25 is fast thereto in any desired manner, as by a key and, keyway 28 (Figs. 4 and 5). 1

The shaft 26 is carried in suitable anti-friction bearings 29 provided in body I0 and head I2, which bearings are mounted in a hole bored eccentric to bore II. These bearings may be of any suitable type. In the present instance I employ ball-bearings. One such bearing is shown in Figure 2 in the head I2, but is omitted in the disclosure of the body I0, for simplicity and conn ence the inner rotor.

While I have disclosed the rotors. as bein Powered through 5118? :1 which: inner rotor iii isms/ole; fast, it is" course. equally feasible to? power the outeralrdtor through any suitable means as by: a spider, axiom permit. the outer rotortoudrrve' the inner rotor Hi In point of or factor have found that pierhapssinooth er action i ng Hillel-'1 rotor t'tl'i are ill various stages of mesiior contact with the i emrini-lig 'dliti rotor rolls. Upon rotationrimparbed to oiior the o'ther of the inner or outer rotors these rotors will be moved at high speed: relative to the casing oomprised by parts It and: i2, and will undergo a siow change or phase relativeto each-other seven rollers 24, while the inner rotor has six teeth so, it will be seenmam/h ooterrotor mtates; ata speed which: is that of the inner iOtOfi r considered from another aspect; it: will be understood thatthis" outer rotor loses one revolucreate a; series of small space'mfilled with fluid.

tion in the course. of every sevenlrevolutions of That is, during the time that it takes for the inner rotoi' 'to accompiisnseven revolutions,- the outer rotonwilb ass througnsix revolutions To' illustrate; lwithtii inner rotor asthe driving rotor: and operatingat say 12-00 revolutions per minute", it clear" by simple a calculation that the outer rotor; revolves so 10285 revolutionspermimitel By subtraction; the outer and innerv rotors,= under such condifiohsgdifiri in numberof rotations by but 171 .5 revoliitionsrper l i It: is to be" notedl that the number and; size" of teeth 3 0 i and rollers determines large :meas- ,ure the ultimatecapacity of the pumpiq It is equally notablethazt proper choice 05 tooth-:con-

tour has appreciable bearing onpumpeflicieney. As suggestedin anearlier part ofthis discussion, thesefactors have all been the subject oil careful study and investigation by earlier workers in the field. Their findings comprise the subject of earlier patents t as wellasarticlesi-n the :general technical literature. Since such design does-not per se comprise part of this inventionne effort will be devoted herein to i a development of such constructional details. By theusekof proper epicycloidal and hypoeycloidar contours. or other ing and antiefrictional contactis maintained between the ciisps- 3c andis'ases. 3| ofl tlie'. teeth suitable shapes itis insured' thatltighiinyet roll the" uter rotor,

Figures 4 and 5, where n are; cusci'osedtne momentary; relationof the inner and" outer roture thereof. The fluid; willows the. smallr arrows in separating at'sthex throat 32; to: course: along upper andi lower parts 33; 34; of manifold; l8.

\ with: the-two rotors'zrevolving at difierent speeds,

there is a: continuous: opening and closing of spaces or compartments defined between the: two

rotors. The: constant, contact of the teeth of the inner rotorwithther rollersof the outerrotor Durin any, small incrementiofI time; some of these spaces are: increasing; in; size. creates asuction and draws fluidfromtheintake mani- 15" fold into these spaces; Qthersr of these spaces are decreasing in size causing pressure;v flhe'se v spaces discharge asthey passtheexhaustmanifoldl At the lowermost edge of manifold portion 34, some of the fluid enters compartment Awdefined at the moment by'roller 24a, tooth 3ilfatooth 30a,

roller 24b and bore 1 l. 'i'he'contactloil-teeth 30] r and 30a with; rollers 24a and- 2411, respectively,

is such that the volumetric; dimensions of the compartment A are at a substantial minimum. An ensuing increase; in volume up to maximum creates a suction drawing in fluid from: manifold l8. n

The fluid continuesto enter compartment; A during rotation of the:two rotm-sxupwardthrough the: are adjacent manifoldll'fli until the compartment A is substantially filledi Meanwhile as compartment A sweeps rapidly in a clockwise direction, indicated by the arrow 35, it is sequentially replaced at thel'oweredge ofmanifoldrportion- 34 by successive 'compartiments LB,v G, etc, which in turn follow throughsthe same-cycle as compartment A. It is tov be noted that as the rotor 25 continues in itsclockwise rotation, oompartment A; having reaohecltacondition of approximate maximum volume tad jacent the lower tip of the lower portion?! of-exhaust manimld l9 during which time fluid from, the 'compartment expelled through port 11-.

,It should be noted that the compartment A is entirely sealed, from the other compartmentslB, C, etc, except through the intake and exhaust manifolds. The s'eal is accomplished lbysnug fit ofthe e'nu pistes 2t, '21 against body ,Hlandhad 12; by the sinus: roiling conta t or the rollers 23 against the cylindrical wall of bore i1; b

thesnug fit o'fthe's'e' rolle'rsagainst the endplates;

' and by the snug Contact of the rotor 25, both with the rollers 24 and withtheins'ide surfaces of the end plates '20, 21. each roller 2! is at all times in engagement with some one or the other of the teeth :30 of the inner rotor"25.

Returning nowxto iurtheruand somewh-atmore detailed "consideration of the volumetric cato a successive phaseoi positionofncompartment A, is seen momentarily to be comprisedbbetween roller 28b, tooth '3lla,ftooth iilllz roller '2lic and bore I'I. 'siibsequentlm during the rotational movement, compartment A reaches station ID.

This is just opposite th-e'uppernicst edge of manifold portion 36; It representsthepositi'on of apmox imateniaximum volumes the compartment. eor'iipress'ioh is "just be giniilirg. "ltwill he observed that compartment D owns iii'omenti's 1 between the rotors.

comprised of roller .Zld, tooth 30c, tooth 30d,

roller 34c and bore II. The fluid begins to discharge through manifold portion 36 along the 1 direction indicated by the small arrows, and

exits through throat 38 and port l1. Pressure discharge continues during the travel of compartment A down past the extent of manifold l9. What has been described with respect to compartment A is true of all of the other compartments such as B and C. As the rotors continue past the position D of approximat maximum volumetric capacity, the compartments defined at this position decrease in volume with further clockwise rotation until a position of minimum volume is reached at the lower end of the eX- haust manifold.

It is the eccentric relation of the inner rotor 25 with respect to the outer rotor, and the design of rotor 25 with one less tooth than there are rolls 24, which give rise to the formation of compartments of continuously varying dimensions. While the rotors rotate at high velocity relative to the casing, nevertheless their phase change relative to each other is comparatively small. Ample time is provided by the long manipulses in such manner that smooth, uniform, nonpulsating pumping action is achieved. The teeth and rollers comprising each compartment are constantly in a process of change and replace- 'ment, due to the relative rotation of the outer and inner rotors, and the teeth defining any given compartment will be entirely different from one revolution to another.

A construction of the type which I have disclosed is comparatively simple and inexpensive to produce. The various component elements are themselves of low first cost and require no expensive manufacturing process. The rollers 24 when constructed of extremely hard steel, ground to size, inherently tend toward long wear. This tendency toward long life and a low rate of wear is contributed to by the slow change of phase The rolling contact between the movin parts in the substantial absence of sliding friction conduces to small change in dimensions during, use. Machined parts remain in close engagement. A tight and effective seal is had. Retention of the seal between the several compartments is maintained over long periods of service. Inasmuch, as the relative rotational speed of the inner and outer rotors is comparatively low, it is entirely practicable to operate the pump at motor speed, ranging as between 900 to 1800 revolutions per minute. The necessity of expensive auxiliaries in the form of speed reducers is effectively avoided. Lubrication is achieved in simple manner by a microscopic film of oil.

While I have described my new device as a pump, and while therein lies its principal sphere of utility, it is of course possible to achieve motor action by reversing the coursing of fluid through the ports of the casing and by permitting the fluid, under pressure, to enter into the compartments of minimum volume, and thereafter to expand the compartment causing a moving and change of rotor position. In such instance power take-off can be achieved through either the in- I claim:

1. A hydraulic pump comprising the combination of a cylindrical casing having inlet and outlet ports therein; nested inner and outer rotors disposed snugly in said cylindrical casing eccentrically of each other, said outer rotor comprising a pair of end plates having corresponding peripherally arranged bearing points and fitting snugly against the faces of said bore; studs extending between bearing points of said end plates, the said end plates and studs comprising a cage; and rollers mounted for rotation on said studs opposite the ports of said casing, the inner rotor having one less peripheral tooth than the number of said rollers, said rollers and teeth being in constant anti-friction rolling contact with each other .to provide, together with the cylindrical inner surface of said casing, a series of sealed compartments of continuously varying dimensions.

2. A hydraulic pump comprising in combination, a casing having a bored body portion with cylindrical inner surface, a head portion adapted to be bolted thereto, dowel positioning means on said body and head for insuring proper assembly thereof, opposed annular ports extending from the exterior through said body portion to said bore, and means for securing said body and head portions together in fluid tight manner; and nested inner and outer rotors disposed snugly in said cylindrical bore eccentrically of each other, said outer rotor comprising a series of rollers mounted on a cage-like bearing frame and opposite the ports of said casing, said inner rotor having one less peripheral tooth than the number of said rollers, said rollers and teeth being in constant anti-friction rolling contact with each other to provide, together with the cylindrical surface of said bore, a series of scaled compartment of continuously varying dimensions.

3. A hydraulic pump comprising a ported casing having an interior cylindrical bore having annular ports on opposite sides thereof each communicating with a separate manifold in said casing which extends through an angle of approximately end plates fitting snugly against the faces of said bore in fluid-tight manner for rotation relative thereto, the said end plates each having a corresponding set of holes disposed in a circle near its periphery; corresponding studs interfitting corresponding holes of said end plates; rollers disposed for rotation on said studs and bearing snugly against said end plates; a pump drive shaft; and an inner, peripherally toothed rotor keyed to said drive shaft and disposed within and eccentrically of said outer rotor and fitting snugly between said end plates, the number of teeth on said inner rotor being one less than the number of rollers, the said teeth and rollers being constantly in fluid-tight contact with each other, and the said teeth, rollers and end plates defining, together with the cylindrical surface of said bore, a plurality of compartments each sealed against the others and each having continuously varying dimerlsibns during the eccentric rotation of the rotors relative to and eccentrically of each other. 4. In a rotary pump of the character described, a housing, a cylindrical chamber within said housing, a pair of oppositely-arranged ports for said housing and chamber, a cam rotor in said chamber, said'rotor having a plurality of identical, rounded, symmetrically-arranged cam surfaces, the axis of said rotor being parallel to butnqtconcentricwith. the axis of saidcylindrical chamber, a roller cage in said chamber between said rotor and said housing, said roller cage supporting a plurality of rollers, the axes of said rollers being parallel to the axes of said chamber and rotor, said roller cage being rotatable on an axis concentric With the axis of said chamber and rollers of said cage being supported by said cage at nxed radial distances from said cage axis, each of said rollers having rolling contact with the cylindrical Wall of said chamber and the cam surfaces 01 said rotor at all times, and means for rotating said roller cage and therewith said rotor in said housing.

5. In a rotary pump of the character described, a stationary housing, a cylindrical chamber within said housing, a pair of ports for said housing and chamber, a cam pump element in said chamber, said pump element having a plurality of identical, rounded, symmetricallyarranged cam surfaces, said element mounted for rotation on an axis extending parallel to but not concentric with the axis of said cylindrical chamber, rollers interposed between said cam element and the cylindrical wall of said chamber, and means for keeping said rollers spaced a constant, arcuate distance apart from each other, said rollers being in constant rolling contact with said cam surfaces and with the cylindrlcal wall of said chamber, the number of rollers being one more than the number of cam surfaces on said pump element.

6. In a rotary pump of the character described, a housing, a cylindrical chamber within said housing, a pair of oppositely arranged ports for said housing and chamber, a cam pump element in said chamber, said pump element having a plurality of identical, rounded, symmetri-,

cally-arranged cam surfaces, said element mounted for rotation on an axis extending parallel to but not concentric with the axis of said cylindrical chamber, a roller supporting element in said chamber between said pump element and said housing, said roller supporting element having a plurality of rollers, the axes of said rollers being parallel to the axes of said chamber and pump element, said roller supporting element being rotatable on an axis concentric with the axis of said chamber, said rollers being positioned by said roller supporting element spaced apart at equal distances around said cylindrical Wall, the number of rollers being one more than the number of said cam surfaces on said cam pump element, each of said rollers having constant rolling contact with the cylindrical wall of said chamber and with said cam surfaces of said pump element at all times, and means for producing relative rotational movement of said pump element and said rollers supporting element with respect to said housing.

7. A rotary pump including a stationary hous ing, a cylindrical chamber within said housing, a pair of diametrically opposite ports for said housing and chamber, a cam pump element in said chamber, said pump element having a plurality of identical rounded, symmetrically-arranged cam surfaces, said element mounted for rotation on an axis extending parallel to 10 but not concentric with the axis of said cylindrical chamber, a roller supporting element in said chamber between said pump element and said housing, said roller supporting element supporting a plurality of rollers, the axes of said rollers being parallel to the axes of said chamher and pump element, said roller supporting element being rotatable on an axis concentric with the axis of said chamber and the rollers of said roller supporting element being supported by said roller supporting element at fixed radial distances from said roller supporting element axis, said rollers having rolling contact with the cylindrical wall of said chamber and with said cam surfaces of said pump element at all times, and means for rotating one of said elements.

8. Apparatus of the character described comprising in combination, a casing having a cylindrical bore therein and inlet and outlet passages therefrom, an outer rotor disposed within the bore of said casing comprising spider means carrying a plurality of substantially uniformly spaced rollers continuously contacting the cylindciral wall thereof, a peripherally toothed inner rotor disposed eccentrically within said outer rotor with the teeth thereof contacting the spaced rollers of said outer rotor to provide a plurality of separate compartments each of continuously variable dimensions with those of the increasing dimensions cooperating with one passage and those of decreasing dimensions with the other passage, and shaft means extending from said rotor spider exteriorly of said casing.

9. Apparatus of the character described comprising in combination, a casing having a cylindrical bore therein and inlet and outlet passages therefrom, shaft means Within said casing eccentric to the axis thereof, a peripherally toothed inner rotor secured to said shaft and eccentric to said bore axis, and a plurality of substantially uniformly spaced rollers exceding the number of teeth of said inner rotor by at least one and as a group forming an outer rotor concentric with said casing bore and continuously contacting the cylindrical wall of the bore of said casing and the teeth of said eccentrically disposed inner rotor to provide a plurality of separate compartments, each of continuously varying dimensions with those of the increasing dimensions cooperating with one passage and those of decreasing dimensions with the other passage.

BARTHOLOMEW FRANK QUINTILIAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,166,999 Loftus Jan. 4, 1916 1,183,309 Loftus May 16, 1916 1,970,146 I-Iill Aug. 14, 193

FOREIGN PATENTS Number Country Date 284,411 Great Britain Jan. 30, 1928 394,985 Great Britain July 5, 1933 535,807 Germany Oct. 15, 1931

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