USRE12797E - Reissued may - Google Patents

Description

RBISSUED MAY 26, 1908.

S. G. DAVIDSON. GENTRIPUGAL PAN 0R PUMP.

APPLICATION FILED MAB.16.1908.

9 BHBETB-SHEET 1.

INVENTOR No. 12,797. REISSUBD MAY 26, 1908. S. C. DAVIDSON. UENTRIFUGAL FANOR PUMP.

APPLIGATION FILED MAILIB. 1908.

8 BHHBTSBHEIIT 2.

INVE NTOR I By Attorrzqys,

WJTNESSES:

all-MM m 5 RBISSUBD MAY 26, 1908.

Ila-12,797.

S. G. DAVIDSON. GBNTRIPUGAL PAN OR PUMP.

APPLICATION FILED MAB.16.1908. I

9 SHEETS--SKEBT 3.

INVENTOR M am By Aim/1103's,

m Ma

REISSUBD MAY 26, 1908.

8. G. DAVIDSON. GENTRIFUGAL FAN OR PUMP.

APPLIGATIOH FILED MAR.16.1908.

9 SHEETS-SHEET 4 INVENTOR WITNESSES:

REISSUED' MAY 2a, 1908.

8. C. DAVIDSON. GENTRIFUGAL FAN OR PUMP.

APPLIUATION FILED MAR.16.190B.

9 SHEETS-SHEET 6 wig/wk /Z ina 22:65-

INVENTOR By Attorm s,

REISSUED MAY 26, 1908.

8. O. DAVIDSON. CENTRIFUGAL FAN 0R PUMP.

APPLICATION FILED MAR.16.1908.

9 SHEETSBHEET 6 I N VE NTOR fi hwfim,

Fig/01714122 am A m??? REISSUED MAY 26, 1908.

S. G. DAVIDSON. CENTRIFUGAL FAN OR PUMP.

APPLICATION FILED MAR.16.1908.

9 SHEBTSSHBET Z IIIIIIIIIIlllnlllnllllllllllllllllllnll INVENTOR WZIlESSES;

REISSUED MAY 2 1903.

S. U. DAVIDSON. CENTRIFUGAL FAN OR PUMP.

APPLICATION FILED MAR.1G.1908.

9 SHEETS-SHEET B NN WN 9 SHEETS-SHEET Q REISSUED MAY 26, 1908.

INVENTOR SN NN S. C. DAVIDSON. CENTRIFUGAL FAN 0R PUMP. APPLICATION FILED MAR 16. 1908.

WITNESSES:

UNITED STATES gENT OFFICE.

COMPANY, or master CITY,

NEW JERSEY,

A CORPORATION OF NEW JERSEY.

CENTRIFUGAL FAN OR PUMP.

Original No. 662,395, defied November 27, 1900, Serial No. 691,491.

Specification of Reisaued Letters Patent. Reissued May 26, 1908.

Application for reisl nefled March 16, 1908.

Serial No, 421,691.

DIVISION B.

T all whom it may concern:

Davinsox, of Belfast, Ireland, have invented bertain new and useful Improvements in Centrifugal Fans or Pumps, (Division 13,) of

which the following is a specification.

My invention has reference to rotary fans or pumps in which the fluid operated on is taken in axially and discharged circumferto entially; and. it relates to centrifugal fans or umps in which the blades carr the fluid with them in their rotation, and thereby throw it outward by centrifugal foree,'as distinguished from propeller fans or pumpsin which the blades act upon the fluid with a wedging action, pushing it from them Without materially rotating it.

The object of this invention is toimprove the etlieiency of such centrifugal fans or in pumps by increasing the volume and pressure of thelluid drawn into and discharged therefrom relatively to their diameter and speed of rotation.

In this specification the word fan is understood as including a pump. The word axially means in a direction coincident with or parallel with the axis of rotation. The word blades is used to indicate the vanes or wings which impart motion to the fluid. lhc expression intake-chamber is employed to indicate a chamber or space ineloscd within the series of blades. The word eye" is used to designate the inlet-opening in the casing or stationary member of the fun, through which opening the lluid enters the intake-chamber. By the intake end of the blades or ports is understood that end which is nearest the eye. The depth of the nlades is their width measured radially from the inner to the outer edge, the

lcngt h ol' the blades is their axial measurement, and the "ports'" are tl spaces between the blades.

According. to any invention the rotary member of the fan is constructml with numerous thin elongated blades arranged in substantially drum form, being extended in ,a iproximately axial direction. so as to inr-lose within them'a relatively large and prac- 60 tically unobstrnctml intake-ehamber, and

said blades in transverse section being arranged relatively to the axis and direetion of i Be it known that l, SAMUEL ELELAND ic intervening l l l l l l l l rotation to carry the fluid with them rotativcly and discharge it. tangentially, and said rotary member is so mounted as to permit the tangential escape of the fluid discharged from its blades. The blades are best made of sheet metal and are elongated-that is to say, their length approximates at the least three times their depth and being preferably as much as nine or more times their depth-- it bein preferable to make them as narrow or sha ilow as practicable consistent with strength of construction. Preferably their inner and outer edges are substantially par allel to each other. The blades must be so shaped relatively to the axis and direction hf' rotation as to carry the fluid with them in their rotation in order to throw it outward by Centrifugal force, whereby it is discharged 7o tangentially. To this end the blades may be made in two or more planes at an angle to each other with their outer edges turned or inclined forward-that is, in the direction of rotationor they may be formed as curved plates with their outer edges turned forward, so that the concave of said curve is on the forward or advancing side, this latter construction being prcfcrrel.

The blades are so numerous as to follow eaeh other in close suceession, being spaced apart preferably a distauee approximating two-thirds of their radial depth, or it maybe as much as twice the full depth of the blades. The drum-like arrangement of the blades is such as to inclose within them an intal cchamber, which preferably is approximatcly cylindrical and which is of large dimensimis as compared with fans heretofore cxistingthat is to say, its diameter approximates at no the least to four times the radial depth of the individual bladcs and in the preferred proportions is live-sixths of the external diameter of the series of blades, and its length or axial dimension approximates at least three times the depth of the individual blades and in the preferred pro portions is a p proxima tel y nine times such depth.

I mount the blades so that while their coneave faces are toward the direction of rotation their outer edgas are tilted forward. Slightly, so that theyhavc a lead in the diri-ction of rotation relatively to their inner edges, whereby the clear width of the ports A Outw uni by between the blades at their outer edges is narrower and consequmitly less in area than at their inner edges.

The drum-like serirs of blades is supported in any suitable inannm' upon ii shaft 0r spindle revolving: in suitable bvzzrings. A GUI! vrnivnl. supporting means consists ii a dish mounted on the )indle, tn whii-h disk tliv bladus are. zittmzhvd SittlltlILllilH remote ruin the intuiiv ends, A ring 01' annular suppnrt is ii'rl'urzibly priivided for the ifiPlHllr'iil or in talie fillil? of i k uiadvs.

'ihirunny Hil'lillJPl' of tilt inn is suitably iilfilllllldl in pvrniit tln tzmgvntiiil vsi'itpv of the iliiid illfillzti'gvl'l iruin its hhnli's. ll not lIlifiaStil, this ilullllitn freely rsica w f'mni it in all dirvcti ins. ll' inislusr-d in ii mining, the hittvr innst 151% so r-nnstructi-d as in pernii the. tnngvnlinl QbTElPE of the fluid as, for PX- :mi ilia, by farming: ihv (using of tho iiauzil snail SlHHM with a tiingvntiiil outlet beyond this piilp wry 0i tln rotary iniiinlwr.

ln throperation (if my ni-w {mi thv fluid flows in axial dirmrtiun intu tliv iiitzikir-cliainbar, in which it PXlJillltlfil without perwptibly revolving until it is caught by tliu bliidcs and drawn into thiports lwtiwvn tlwni. Wilil'tlu) the iluid in tlivsu pnrti: in runwrtvd intu :1 Whirlii'ig shvll of fluid WllL'I'PliY ii is ilEF-WVT] ui-nti'ihigiil i'iii'r'v and disnln'iigi s from the huh-i sidi-s and expanding shrill iil' lluiil, the indii'idiinl particlvs of which ninw in tiiiigri-ntiiil illl"i'itiun. Tlw lJilUli'H nnso llzilI'UV and Si: Plow tngethPr that nu mli'l yi'ni'rvnts arv unused in the ports lwiwvvn tliwni. thus avoiding: the loss of eiiiuiini-y and tin whirring or limiting noise aiicmnpziiiyiiig tliiupvriitiim iii ri iii ril ugal fans as lit'l'iiuflil? made.

In my prvi'e'rri-i'l runsirui-tiiin iliiininliv ends of the l)l2l(llfi 21H ii wn tn thv inilm-viiir fluid, an that tliilliiiil may ilmi iixiiilly iniu the intzilu lliLlS ni' ilii ports. lii this (Elfii l is & sectinniil (lPVUilUH on tho linv l 1 nl Fig. 2, illustrating ihv |)l(l('i]'ill.iilllllltllment of my invi-ntinn. Fig. '3 in il r riihxat i l l l l l i l the intake ends of ihv blades, showing (he-l thi nvxt.

s paces between isiu cflicicncy is not obtnincd.

the blades are, lettered 2 e. In Fig 3 it will be noticed that the width of these parts at 0:, near the outer edges of the blades, is somewhat less than at y, their inner edges, owin to said outer edges of the blades, bein tilted slightlyforward relatively to the radia line 2. By thus turning forward the outer edges of the blades the outer or discharging area of the ports is reduced to less than their inner or-inlet area. The same result may be attained with angle-blades, as shown, for exam is, in Fig. 12".

n proportioning the parts I make the length of the blades such that the aggregate 0 en area of the ports around the periphery of the fan shall be at least equal to the arca of the inlet (1 )ening when the maximum volume of inta e and discharge is required: but the length of the blades may be vuricd to suit any special requirements.

The prefcrrcd proportions of my fan are shown in Figs. 1 and 2, wherethe radial depth of the bladcs is one-twelfth of the diameter of the fan and the length of thc blades is nearly nine times thcir This construction all'ords a large intakechamber of up roximatcly cylindrical form,

the diamctcr 0 which is tcn times the depth of the individual blndos, whilc its lcngth, equaling that. ol' the bladcs, is about ninc times this dilncnsion.

Thc bladcs in Figs. 1, 2 and 3 arc shown spaced apart a distancc approximating onchalf their radial dcp th.

Thc provision of a rclativcly lnrgc intakeohambcr in connection with shallow bladcs following cach othcr at frequent intcrvnls is a distinclivc l'cnturc of my invcntion. ln fans as ordinarily construcicd, cmploying blades of great radial nicasuromcnt, supplcmcntnry vibrations and crldics urc-scl up, which rcducc thc cllicicncy ol' lhc ion. in thosc fans also in which thc blndcs arc cxtcndcd inwardly to or ncar thc axis tho bcsi l havc discovcrcd that by providing a rclntivcly largo intnkcchambcr practically nnobstructcd by lhc proicclion into. it of blndcs or olhcr ports and by cinploying blndcs which cxlcnd as short n dislnncc from tho pcriphcry ol' thc inn 1 inward us is consistcnl with strcngth ol' construction, lhc snid snpplcmcntncv vibrations and cddics urc minimizcd and tho vclocity and volume of lluid dischargcd for a given spccd ol' rcvolnlion :u'c grcatly incrcascd.

Thc bludcs may bc bcnt angularly as shown in Fig. 12", or they may be curved. as shown in Figs. 1 and 3. the curved l'orm being prcl'crublc. Tho dcpth of thc hladcs may bc incrcnscd to thc cxtcnt shown in Fig. 14, whcrc thc intnlrc-chambcr is rc duccd To adinmctcr four times thc dcpth of thc individual bhidcs.

It has hitherto bccn considcrcd impossible to gct prcssurc or partial exhaust with condepth. I

l trifugal fans unless the blades are inclosed I on the sides and the eye or opening is of not igreater diameter than about one-half the l With my present in eye may he of e ual diameter of the fan. vention, however, the diameter to that'of the fan pcri ihery. his is clearly shown in Fig. .2. This is made ossible by making the intake ends of the lades 0 en or unobstructed, so as to form open-en ed ports between them. To SL1)- )OIl; and strengthen the intake'cnds of tie blades, I prefer to make them laterally curved or spoon-shaped or concavo-eonvcx, as shown atl in Figs. 6 to 11.

hen greater strength of construction is required, as when the fan or pump has to be driven at a very high velocity, or when it has to be employed for )umping a hcavy lncdium, as a liquid. the lnllllii ends of the blades may be closed in thc mnnncr shown in Figs. 24 to 27, inclusivc. In the modificntion shown in Figs. 24- and 25 the intake ends 1 of the blades are closed by projecting the [hinge of thc encircling ring dinward.

In the modification shown in Figs. 26 and 27 the intake cnds arc closcd by a flat connccting--ring, to which thcy arc :ittnchcd in thc sumo marincr as lhcy arc attached to the disk 5 at thcir oppositc ends,

It obvious that in thc inn or pump shown in Figs. 1 and 2 and also in othcrs (shown, rcspcctivcly. in Figs 12, and 14 and in thosc shown in Figs. 24 to 27, inclusive) the casing 11 may pi'ojcct inward over the cdgcs of thc blndcs c P, but thc inlct-opcning or cyc to thc l'nn should not bc thcrcby rc dnccd 1o lcss than. fi vc-sixths of thc diamotcr of thc inn. (hee dottcd lincs in Figs. 24 and so.

It is csscntial to my invcnlion inal lhc innbhnlcs shall bc ndn )tcd lo run-y lhc lluid with lhcm rotntivoly, so that it shall be thrown outward by ccnlril'ugnl l'orcc and bc dischargcd tangcnlially, in contrmlistinction lo mcrcly cxcrting a wcdgc-likc.action upon lhc liuid, lcnding to thrust it outward in radial dircction unaccompunird by nny nmlcrial rotation or whirling of thc lluid. in a true ccntril'ugnl hm i1 is almost solcly lhc F Four surlncc olthc lilndc which acts upon lhc lluid, drawing it around by suction, whcrcns in bladcs which thrust lhc lluid outward by n wcdgc-likc action it is thc front or ndvnnc mg sldc ol lhc bladc WlIH'li is lhc aclivc bu-c.

Bladcs ol thc hiltcr kind rcquirc to bc inclined or curvcd rcarwurdly to a considcr able anglc, so that the outer edge follows bchind thc middle or major portion of tho bladc. l usc lhcexpression "in transvcrsc sccwtion arranged, relatively to thc axis and direction of rotation, to carrv thc iluid with thcm rotntively and dischargc it tangentially to cxcludc such wcdging blades and include generically any form of blade adaptcd to act upon,thc air by rotating 0r whirling The operation of my fan when propelling air is acconmauied by the existence of a thin shell or him of rapidly-wlnrlmg air munedil ately surrounding the drum-like series of blades, which air is ap )arently compressed, and outside of this shell the air discharging from the fan escapes tangentially. Whether the fan is provided with a casing or not the construction must be such as to permit the whirling fluid discharged from the blades to escape tangentially therefrom in outward di rection.

To realize the full advantages of my inven tion, it is practically essential that the inflow of fiuid to the intake-chamber be unobstructed and that the inlet-opening be of the full diameter of said chamber, as any throttling of this opening results in a proportionate dim inution of volumetric efliciency. It is also practically essential that the whirling fluid discharged from the fan-blades shall be permittcd to escape tangentially outward therefrom, as any attem it to divert the revolving fluid inwardly results in a rapid diminution of efliciency; but the whirling fluid can be collected in a casing, and if the outlet from this casing be arranged beyond the radius of the circle described by the outer edges of the blades the fluid will freely escape through said outlet, its whirling motion being thereby resolved into a direct motion, after which it can bc led through a suitable conduit in any desired direction.

The fan provided by my present invention is distinguished from that shown in Fig. 7 of my llnitcd States Patent No. 544,758, wherein the blades are triangular and project into the central hub, that in my present form the blades are extended approximately parallel to the axis of rotaiion, being arranged in drum form, so as to inciose within them an approximately cylindrical intake chamber which is practically unobstructed by blades or other )arts.

mod her is uuiucloscd by any casing, so that the. lluid discharged from the blades may freely escape tangentially in all directions, is not spccdi all v claimed in my present appl1cation, this feature being so claimed in my application, Serial No. 17,366, filed May 21, teen, (Patent No. (362.397, dated November .37, W00) which is a division of my present ap lication. i

l make no claim in my present reissue to that feature of the invention set forth in my original lietters Patent which is characterized by the revision of a relatively large intake chain er with numerous elongated blades which are so narrow radially and so remote from the axial center that. their inner edges revolve at a peripheral speed so nearly ilication wherein the rotary mem-.

approaching that of their outer edges that fluid is drawn in at their inner edges at aproximately thesame rate as it is discharged from their outer edges; or, otherwise stated,

that the ports between the blades are not materially wider at their exterior or discharge ends than at their interior or inlet ends; this being claimed generically in another reissue (Division A) of my original Letters Patent,

\ angu ar or curved in cross-section; and irres eotive of whether the orts between the b ades are of substantially uniform width and area at their interior or inlet ends, and at their'exterior or outlet ends, or are of diminished width and area at their outlet ends.

l The present reissue (Division B) of my l original Letters Patent is directed to those l features of my invention which are charac- 1 terized by the inclining of the outer edges of l the blades forwardly or in the direction of rotation to such effect that the outer width 1 of the ports between the blades is no greater (and is preferably less) than their interior or i inlet width; and by the employment curved blades with their outer edges so inclined forwardly in advance of their inner edges, and which are concave on their advancing sides. Such forward inclination of the blades results in the disch l at a velocity exceeding the circumferential l speed of the outer edges of the blades; this 1 effect is most marked when the outer width of the ports is less than their inner width.

l 1 make no claim in my present reissue to that feature of my invention which is characterized by the blades being open-at, their intake ends (being preferably curved transversely at their intake ends to stiffen theml this being claimcd in another reissue (Division Cf) of my said original Letters Patent.

I claim as my invention the following de lined novel features, substantially as hereinbefore specified, namely 2 1. A centrifugal fan or pump, comprising a rotary member having numerous elongated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inelose within them a relative] y large and practically unobstructed int akc chamber, and in transverse section arranged, relatively to the axis and direction of rotation, to carry the fluid with them rotatively and discharge it tangentially, said blades being inclined forwardly in the direction of rotation and proportioned substantially as set forth, and a means for so mounting said rotary member as to permit the tangential escape of the fluid discharged from said blades.

2. A centrifugal fan or pump, comprising a rotary member having numerous thinelom gated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as tti inblose within them a relatively large and practically-i1nobstrueted l l l irres ective of whether the blades are radial,

arge of the fluid intake-chamber, and ,in transverse section arranged, relatively to the axis and direction of rotation, to carry the fluid with them rotatively and discharge it tangentially; and spaced apart a distance no greater than twice their radial depth, said blades being inclined forwardly in the direction of rotation to such effect that the outer or discharging width of the ports between them is not greater than their interior or inlet width, and a means for so mounting said rotary member as to per mit the tangential escape of the fluid discharged from said blades.

33. A centrifugal fan or pump, comprising a rotary member having numerous elongated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and prac-tically-unobstructed intakechamber having a diameter equal to at least four times. and an axial length exceeding three times, the radial depth of the individual blades, and said blades in transverse section arranged, relatively to the axis and direction of rotation, to carry the fluid with them rotatively and discharge it tangentially, said blades being inclined forwardly in the direction of rotation and proportioned substantially as set forth, and a means for so mountingsaid rotary member as to permit the tangential escape of the fluid discharged from said blades 4. A centrifugal fan or pump, comprising a rotary member having numerous elongated blades of a length approximating nine or more times their radial depth, said blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and. practically-unobstructcrl intake-chamber of a diameter approximating ten times the radial depth of the individual blades, and in transverse section arranged, relatively to the axis and direction of rotation, to carry the tluid with them rotatively and discharge it tangentially, said blades being inclined forwardly in the direction of rotation and proportioned substantially as set forth, and a means for so mounting said rotary member as to permit the tangential escape of the fluid. discharged from said blades.

:"1. A centrifugal fan or pump, comprising a rotary member having numerous elongated thin blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and 1iractically-unobstructed inteke-chamber, and in transverse section having their outer edges inclined forwardly, in the direction of rotation, to such effect that the outer or discharging width of the ports between them is not greater than their interior.

or inlet width, whereby to carry the fluid with them rotatively and discharge 1t tangcutially.

6. A centrifugal fan or pump, com rising a rotary member having numerous e ongated blades arrangedlengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and practically-unobstructed intakechambcr, and in transverse section having their outer edges inclined forwardly, in the direction of rotation, to such-effect that the outer or discharging width and area of the ports is less than their interior or inlet width and area, whereby to carry the fluid with them rotatively and discharge it tangentially. 7. A centrifugal fan or pump, comprising a rotary member having numerous thin elongated blades arranged lengthwise in approximately axial directions, and in substantially drum form, so as to inclose within them a relatively large and practically-unobstructed intake-chamber, and in transverse section curved in the direction of rotation, and inclined forwardly in the direction of rotation and proportioned substantially as set forth, whereby to carry the fluid with them rotatively and discharge it tangentially.

8. A centrifugal fan or pump, comprising a rotar member havin numerous thin elongate blades arrangeddengthwise in approximately axial direction, and in substantially drum form, so as to inclose within' them a relatively large and practically-unobstructed intake-chamber, and in transverse section curved in the direction of rotation, and having their outer edges turned forwardly in advance of their inner edges, whereby to carry .the fluid with them rotatively and discharge it tan entially.

9. centrifugal fan or pump, com rising a rotary member having numerouse ongated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and praetically-unobstructed intake-chamber, and said blades formed as curved plates having 'their outer and inner e'dges turned forward in the direction of retation so that the blades are concave on their advancing sides, and inclined forwardly to such effect that the outer or discharging width of the ports between them is not greater than their interior or inlet width.

10. A centrifugal fan or pump, comprising a rotary member having numerous elongated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and practically-tinobstructed intake-chamber, and said blades formed as curved plates having their outer edges turned forward in the direction of rotation, and arranged .with a forward angle or lead, with their outer edges in advance of their inner edges, so that the outer or discharging area of the ports is less than their interior or inlet area.

11. A centrifugal fan or pump, comprising a rotary member having numerous thin elongated blades arranged lengthwise in approxiinately axial direction, and in substantially drum form, so as to inclose within them a relatively large and practically-unohstructed intake-chamber, and in transverse section arranged, relatively to the axis and [lift-t tion of rotation, to carry the fluid with them rotatively anddischarge it tangentially, and having their outer edges turned forwardly to such effect that the outer width of the orts between them is not greater than their 1nnerwidth,a disk on which said blades are mounted at one end, and an annular support for the opposite endsoi' said blades, and a means for so mounting said rotary member as to permit the tangential escape of the fluid discharged from said blades.

1;. A centrifugal tan or pumpn' omprising a rotary member having numerous thin elongated blat'les arranged lengthwise in approximately axial direction, and in substantially drum form, so to inclose within them a relatively large and practically-unobstructed intake-chamber, and in transverse seetion.arranged, relatively to the axis and direction of' rotation, to carry the fluid with them rotatively and discharge it tangentially, and having their outer edges turned forwardly to such etfect that the outer width of the ports between them is not greater than their inner Width, a disk on which said blades are mounted at one end, and an annular sup )ort for the opposite ends of said blades, said blades formed with iii-- tegral flanges at their opposite end and rivets uniting said flanges to said dis ind annular support respectively, and a 1 ms for so to permit mounting said rotary member *iseharged the tangential escape of the iluit; from said blades.

13. A centrifugal [an or pump stationary and rotary members. member having numerous thin in prising lllt i'otal') elongated blades arranged lengthwise in approximately axial direction, and in substantially drum form, so as to inclose within them a relatively large and practicelly-unobstructed intake chamber, and in transverse section arranged, relatively to the axis and direction of rota tion, to carry the fluid within them rotatively and discharge it tangentially, said blades being inclined forwardly in the direction of rotation to snch eil'ect that the outer or discharging width of the ports between them is not greater than their interior or inlet width, and said ports closed at both ends, and the stationary member having an eye through which the fluid is drawn coincident with said intake-chandier'and of a diameter substantially equal to that of said chamber, and having means for so mounting said. rotary member as to permit the tangential escape of the fluid discharged from'said blades.

H. A centrifugal fan or pump comprising stationary and rotary members, the rotary member having numerous elongated blades rrangod lengthwise in approximately axial direction, and in substantlally drum form, so as to inclose within them a relatively large and practically-unobstruetcd iutake-cham ht-r and in transverse section arranged, relati ely to ih axis and direction of rotation, to

arry the [laid with them rotatix 'ely and diswhi 'ge it tangentially, said blades being inclincd. tori-vardiy in the direction of rotation to u h ell'ect that the outer or discharging width oi the ports between them is not greater than their interior or inlet width, and the stationary member having an eye through which the lluid is drawn coincident with said inteke-chamber and ot a diameter substantially equal to that of said chamber, and having means for so mounting said ro tary member as to permit the tangential escape of the tluid discharged from said blades and the aggregate eli'ectivtarea of the ports between the blades of said rotary member at least equal to the area of said c ve.

t5. A centrifugal fan or pump comprising stationary and rotary Jittliilmi's. the rotary member having numerous elongated blades arranged lengthwise in apprtixiioutely axial direction, and in substantially drum form, so to int-lose within them a rclutiuly large and practicalli unobstrut-ted intake-chainher, and in transverse section armory-d. relatively to the axis and direction oi rotation, to carry the fluid with them rt'natiwly and discharge it tangentially, said blath being inclined forwardly in the direction f rotation to such cll'cct that the outer or discharging width of the ports between then] is not greatiu' than their interior or inlet width. and said ports closed at both ends, with supports tor the opposite ends of the blades, and said blades lornied with inturned linnges at their opposite ends, and rivets uniting said [hinges to said -upports, and the stationary member comprising a casing adapted to permit the tangential escape of the ilnid dischargml from said blades,

ln witness Whcteol l. have hereunto signed my name in the presence oi t\\'o subscrihing n ituesscs.

Witnesses:

Gannon (loom) \iituu, (iEt'Hl lh ilnun' ()HWALU Frrnujlt.

Hit)

lib

Correction in Reissue Letters Patent No. 12,797.

It is hereby certified that in Reissue Letters Patent No. 12,797, granted May 26, 1908, upon the application of Samuel Cleland Davidson, of Belfast, Ireland, for an improvement in .Centrifugal Fans or Pumps, an error appears in the printed speeilicalion requiring correction, as followsz ln line 2, page 3, the word fparts should read purl-s; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiiee.

Signed and sealed this 16th day of June, A. 1)., i908.

G. O. BILLINGS, Acting Commissioner of Patents.

[SEAL]

Images