US2656971A - Combined fluid impeller and selfsealing closure - Google Patents

Description

E. A. MADER Oct; 27, 1953 COMBINED FLUID IMPELLER AND SELF-SEALING CLOSURE 4 Sheets-Sheet 1 Filed March 22, 1950 Oct. 27, 1953 E. A. MADER 2,656,971

COMBINED FLUID IMPELLER AND SELF-SEALING CLOSURE Filed March 22, 1950 4 Sheets-Sheet 2 INVENTOR. EMIL- A. MADER.

ATTORNEY,

Oct. 27, 1953 E. A. MADER 2,656,971

COMBINED FLUID IMPELLER AND SELF-SEALING CLOSURE Filed March 22, 1950 4 Sheets-Sheet a INVENTOR. EMIL A. MAOER.

A'r'ToRNEY,

Oct. 27, 1953 E. A. MADER 2, 6, 71

COMBINED FLUID IMPELLER AND SELF-SEALING CLOSURE Filed March 22, 1950 4 Sheets-Sheet 4 INVENTOR. EMIL A MADER 54 ATTORNEY,

Patented Oct. 27, 1953 UNI-TED STATES PATEN T OFFICE '7 assasu ooivmmno FLU'mIIMPE'LiJEItI AND V SEALING CLOSURE 4 l l l Emil A. Madden-Detroit, Mich., assignorot one-- half to John Spargo, Detroit, Mich; Apiuic'anantramn sz, 1950; Serial no. 151,256 1501mm: on. 230414) This invention relates to con lbiried. fluid impellers and closuresfaiid particularly'to a provision for establishingan efiective'seal, in' a closure-formingposition of a set of impeller blades, between suchblades and the margin of an opening through which a fluid is impelled, such provision affording centrifugal shifting of the blades to theirimpelling position.

Various 'swivel-bladed impellers have been de-j veloped, employing spring means to swing the blades, when idle, "to afclosure-forming position, and centrifugallyestablishing their impelling positions 'uponimpeller rotation, thus being adapted 'tQeither'I-clOse an air flowopening or. induceafiow throughsuch opening- Suchim? pellersyhowever', quite; imperfectly exercise their closure function, notfonly lacking provision for firmly seatingthe propeller tips against the margin ofsaidopening, but being unsuited to any such seatingdue to necessity of a clearance-adequate for swivel travelofthe blades between their two positions of use With such prior constructions, moreover, any peripheral seating of the bladesagainst a figedsur face for closure purposes. would entail frictionan'd undesirable noise'upon applicationofadrivel i An object of the-invention is to imposetwo distinct spring forces on a set of centrifugally actuable blades, one "such force. resisting response of the blades to centrifugal force, and the other maintaining'a seal when the blades form "a closure. v M v Anotherob je'ct is to subject a set of centrifu' gally actuable blades to twospringsone resisting centrifugal actuation ofj the several blades," and the other establishing and maintaining a seal when the bladesare-olosed Another objectis to adapt a set of centri'fugally", actuable impeller blades to peripherally have firin sealing engagement, when idle, with the margin of anopening closed by such blades, and toauto matically' shiftthe impeller bodily along its axis] to break such engagement, upon the application. ofa drive 'and preliminaryto centrifugal actua tion of the blade'si M Another object "is to subject a set of centrifiigally responsive impeller blades to a spring resisting their centrifugalactuation, such spring acting through an element slidable along theim-Qj ends of theb1ade s in their closure-forming position. W H H I Anotherobject'is tdempldy interengaged s'crew} threads *on 'the""hub a shaft of closurefformjj mg impeller to shiftsuoh' impeller along its axis responsive to an initial driving force, thereby breaking a en at theblade tips, and to adapt a torsionspring, in conjunction with said threads, to return the impeller to its seal-forming position, when the drive is' cutofi.

Another object is to provide a pair ofcoacting clutch elements respectively fixed on the impeller hub and shaft, and to automatically engage or disengage such elements by an axial travel of the impeller deriving from a screw-threaded engagement of said hub and shaft. i ,1

Another object is to afiord 'saidjelutch elements considerable relative jrotative play, and to lock the impeller hub against rotation relative to the shaft when the clutch elements assume their correct driving relation. V l V p I Another object is to automatically collapse a set of impeller blades to. a ,frusto conicalclosure form whenpower is cut off, and to establish leakage-resisting sealsfat theftips of the collapsed blades, attheirinner ends, and at their lapped m ins. i p

These and various other objects are attained. by the construction hereinafter described and illustratedin the accompanying, drawings, wherein:

Fig 1 is a diametrical sectional View of my improved dual purpose. impeller, showing its blades positioned to close an air flow opening in a panel.

Fig. 2 is a similar sectional view, showingan impellingposition oi the blades and their clearance relationtosaid panel; M

Fig- 3 is a rear elevational view of the impeller and panel, showing the closure-forming position.

of the blades, n hub being in section, as indicated by the line 3 -3 of Fig.1.

Fig l is a viewi in front elevatio n and partial section of a drive 'e lement jor, the impeller, the plane of section being indicated by the line 4-4 Fig. 5 shows lin a tlgrmsea on the hub portion of a modified .dual function impeller, occupying its closure position,

6 is a sectional detaiL take n on the line 6-6 of. Fig. 5, and. further illustrating a certain:

pin-actuating 'mechanism employed in said modification. I l In these views, the reference character I desig- M M e nates the shaft of a motor (not shown) on which Pelleraxisand establishing a S al at the inner 'I shaft is fixed an aligned impeller shaft 2.

AS illustrated, an extremity of the motor shaft is inserted in asocket t of the impeller shaft and rigidly securedgtherein by a set screw '4. The midportion of the impeller shaft is formed with a screw thread 5, meshing withthe thread of a feed-nut 6 formed centrally of a web l carried by an impeller hub 8. Between such hub and the motor shaft, there is fixed on the impeller shaft a clutch disk 9 laterally carrying a driving lug Hi. The hub flares in a hollow frusto-conical form from its web toward the disk 9 and rigidly carries a clutch lug ii to be driven by the lug Iii. Rigidly mounted on said flared portion of the hub in a circular series, is any desired number of spaced pins i2 normal to and outwardly projecting from such portion, there being six such pins in the illustrated construction. Upon each pin 12 is swiveled an impeller blade 13 of substantially a sector shape, the mounting means being a bracket i4 fixed on the inner portion of the blade and elongated along one of its substantially radial margins. The .described engagement is suitably maintained, as by cotter pins l set into the outer ends of the pins la. The blades.

I3 are similarly circumferentially curved in a manner adapting them to jointly assume a hollow frusto-conical'form when swiveled to'their closure-forming position, best appearing in Fig. 1.

Rigidly secured to the web I by screws Hi are inner and outer spaced sleeves l1 and i5 coaxial with and outwardly spaced from the shaft 2. Such sleeves extend toward the free end of said shaft, the inner sleeve mounting a torsion spring 19 and the outer one a compression spring 20. The ends of the torsion Spring are secured respectively to the web 1 at 2| and to a collar 22 at 23, such collar being clamped by a screw 24 against the free end of the shaft 2. Upon loosening said screw, the torsional stress or" the spring [9 may be regulated by a rotative adjustment of the collar. An outer abutment for the spring 28 is formed by a collar 25 fixed on the corresponding end of the sleeve l8 by a set screw 25. Slidable on the sleeve 18 under pressure of the spring 20 is a blade-closing annulus 2? having an outer portion 28 encircling a cylindrical portion 28a of the hub, and having a coned flange 29 parallel to the pins i 2 for applying pressure to the blades. The disk 9 rigidly carries a tubular guide 30 for a latch pin 3| slidable to and from the web "I and urged by a spring 32 toward the web. In the latter is an orifice 33 so located as to register with said pin when the clutch lugs id and i l are interengaged. For ejecting the pin 3! from said orifice preliminary to disengagement of said clutch lugs, an ejector in 34 is fixed on the annulus 21, in permanent registration with the orifice 33, so as to enter or withdraw from the latter according as the annulus occupies its maximum or minimum proximity to the pins [2. As will presently more fully appear, the purpose of the latch pin and its coacting ejector pin is to prevent a premature release of energy stored in the torque spring l9.

It is desirable to reduce and cushion the force of impact as the lug ill encounters the lug II, to avoid consequent undue noise and wear. Thus the disk 9 carries on a pin 35 a small coiled spring 36 having an end portion urged to a position against a stop pin 3? and spaced in such position slightly from the lug it in its driving direction under non-driving conditions. Said spring is forced back against the lug It! as the latter closely rotatively approaches the driven lug ii, thus reducing the impact force.

The described impeller serves, when driven, to draw air through a circular opening 38 in a sheet metal panel 39, and provides a closure for such opening under non-driving conditions.

'sure form, tightly lapping one another.

'blade'tips are firmly sealed against the venturi Marginally of its opening 38, the panel has a venturi-shaped portion 40 against which the blades [3 seat firmly as their rotation ceases. The horizontal bottom margin of said panel forms a trough 4! receiving any small amount of moisture that may occasionally leak past the closed blades.

In operation of the described device, the impeller, when idle, lies in its limiting position of axial travel shown in Fig. 1, the clutch lugs l0 and H occupying different planes of rotation, the spring it being largely relieved of torsional stress, and the spring 20 acting through the annulus ill to firmly hold the blades in conical clo- The 40 responsive to a stress applied to the feed nut t by the thread 5. The ejector pin 34 is entered in the orifice 33 and the latch pin 3| withdrawn from such orifice.

Upon applying a drive to the impeller shaft,

the hub 8 is shifted by one or several initial revo-- lutions of said shaft to its position shown in Fig. 2, due to interengagement of the feed nut 6 and screw thread 5. The described shifting breaks the seal between the propeller tips and venturi (it, establishing ample clearance for a subsequent swiveling of the blades on the pins 12 and for free rotation of the impeller. Also such axial shifting establishes the clutch lug i l in the rotative path of the lug in, whereby an impeller drive is established. At the instant of interengagement of said lugs the latch pin 3| snaps into the orifice 533, preventing further relative rotation of the hub and shaft. The described initial rotation of the shaft relative to the hub 8 materially increases torsional stress acting in the spring l9. As the impeller picks up speed, the blades swing centrifugally on. their pins l2, reacting on the annulus 2? to increasingly space it from said pins and impose increased compression on the spring 20. The inclination of the pins [2 is such that the blades acquire their most efiective position for air impulsion, in centrifugally swiveling on such pins, and it is preferred to positively establish said effective position by engaging the free radial edges of the blades with an annular flange 42, peripherally formed on the disk 9.

Upon discontinuance of the drive, the centrifugal effect on the blades rapidly decreases, permitting their return to a frusto-conical form under thrust of the spring 20. In applying such thrust, the annulus 2? slides toward the pins I2, permitting the pin 3 on such annulus to eject the latch pin 3! from the orifice 33, whereupon the torsion spring [9 releases its stored energy, rotating the impeller relative to its shaft to feed the nut 6 and hence the entire impeller to its closure position (Fig. l), establishing tight sealing engagement between the blades and venturi 4 0. The function of the latch pin 3! is to assure a unitary deceleration of the shaft and impeller, after discontinuance of a drive, until the spring 20 overcomes the diminishing centrifugal swiveling effort of the blades, and establishes their frusto-conical closure form. As has been described, this ejects the latch pin 30 from the orifice 33, and the torsional energy stored in the spring may then sufiiciently rotate the impeller relative to its shaft to screw-feed the impeller into a firm sealing engagement with the venturi 40. When such sealing engagement is established, deceleration of the impeller is so nearly completed that friction arising between the blade tips and venturi is negligible. If the latch pin II were not provided, the torsion spring might take effect prematurely, throwing the blades against the venturi while still under centrifugal influence and prior to their reduction to a conical form. This would cause considerable noise, with undue wear and possibly more serious damage.

When an impeller of the described type is functioning as a closure there are three possibilities of air leakage. It has been explained how the torsion spring l9 serves totightly seal the blade tips against the venturi, and how the compression spring 20 seats the blades firmly one upon another. The third leakage possibility occurs at the juncture of the blades with the hub, it being impossible to conform the inner margins of the blades fully to the hub, since clearance must be adequatefor swiveling of the blades, in responding to centrifugal force. The annulus 21, and particularly its flange 29, so firmly engages the inner ends of the blades in their closure-forming position as to eliminate any material airflow past said ends.

Describing now the modification shown in Figs. and 6, the shaft 2a with screw thread 5a, the feed nut 6a, web la, clutch disk 9a, blades l3a, sleeve Ila, torsion spring 19a, and collar 22a all conform to thepreceding description. The modified hub 8a is fully cylindrical and. rigidly carries a circular series of pins I 2awhich are normal to the hub axis. Brackets I 4a which swivel the blades on thepins have blade-engaging portions so divergent to the pins as toimpart the desired conical inclination to the blades, when non-rotating. Torsion springs 43 on said pins urge the blades to their coned closure position,

and upon imposing a suflicient driving velocity,

the blades swivel centrifugally on the pins [2a to their impelling position. An annulus 21a, having a flange 29a coned to conform to the closed blades, serves in this modification solely for sealing the inner ends of the blades, and hence requires only a set of relatively light springs 44 to urge it against the blades. Said springs are carriedby pins 45 fixed on the hub and serving also as slide guides for the annulus. One of the pins l2a is tubular and receives a. rockshaft 46 having a collar 41 fixed on its outer end and pinned at 48 to the bracket I la mounting a blade on said pin, whereby any swivel a-ctuation of such blade entails a corresponding rocking of the shaft 46. The latter extends sufficiently into the hub to rigidly carry a pinion 49 meshing with a rack bar 50. This carries an ejector pin 34a corresponding fully in function to the previously described pin 34. The pin 34a ejects a latch pin 3 la from a hub orifice 33a, following discontinuance of a drive and such diminution of centrifugal influence as permits swiveling of the blades to their closure position. In starting the impeller, centrifugal swiveling of the blades to their impelling position withdraws the pin 34a from the orifice 33a and allows entry of the latch pin 3Ia.

The described invention, in eliminating the considerable leakage that has characterized prior dual functionimpellers, when serving as closure, imparts to such impellers a practicality they have lacked. Heretofore, louver type closures have been extensively used in conjunction with ventilating impellers to close the air flow openings, when the impellers were idle. By deriving a closure function from the impeller blades, amuch heater and more compact installation is achieved than permitted by use of louvers, and the present invention assures a more perfect seal; automatically established, than has as yet been derived other to forman approximately conical closure and an impelling position in which said blades. are circumferentially spaced and diagonal to the plane of rotation of said pins, and springmeans on said hub and including means engag ing said blades for urging the blades about their swivel axes toward saididle position, the impell-- ing positions of the blades being centrifugallyestablished responsive to a predetermined applied; rotational velocity.

2. In a combined impeller and closure of the type comprising a hub, a set of impeller blades outwardly extending from the hub, elementscarried by the hub in a circumferentiallyspaced and approximately radial relation tothehub and establishing circumferentially spaced axes approximately radial to the hub, means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means urging the blades about said axes toward their closureforming position, and means connected, to the hub for rotatively driving the impeller, the blades being centrifugally actuable about said axes to their impelling position responsive to a predetermined velocity applied by said drivin'gineans, the combination with said hub, blades and spring means, of an annulus. engaged by the spring means and transmitting the effort. of such means to the blades and lapping their inner ends to establish a seal in their, closure position, and means mounting such annulus on the hub to slide rem.- tive to the hub along the impeller axis.

3. A combined impeller and closure as set forth in claim 2, said means mounting the annulus being a sleeve coaxialwith andforming an extension of the hub.

4. In a combined impeller and closure of the type comprising a hub, a set of impeller blades outwardly extending from the hub, elements. calried by the hub in a circumferentially spaced'and approximately radial relation to the hub and establishing circumferentially spaced axes. approximately radial to the hub, means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means onsaid hub and including means engaging said blades for urging the blades about saidaxes toward their closure-forming position. and drivingmeansconnected to the hub for rotating the impeller, the blades being centrifugally actuable about said axes to their impelling position responsiveto a predetermined velocity applied bysaid driving means, the combination with said blades and hub, of a sealing. means coacting with the. blade tips to derive their closure-formingfunction,said driving means affording the impeller a, travel along the impeller axis and meansresponsive-to 7 initial nrgization of the driving means for shifting the impeller'along said axis and thus clearing the blades from said sealing means, and automatically responsive to deenergization of the driving means for reversely shifting the impeller to engage the blades with the sealing means.

5. In a combined impeller and closure of the type which is correlated with a member defining an opening for fluid flow, and which comprises a hub, a set of impeller blades outwardly extending from the hub, in a \circumferentially spaced and approximately radial relation to the hub and establishing circumferentially spaced axes approximately radial to the hub, means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means on said hub and including means engaging said blades for urging the blades about said axes toward their closure-forming position, and driving means connected to the hub for rotating the impeller, the blades being centrifugally actuable about said axes to their impelling position responsive to a predetermined velocity applied by said driving means, the combination with said hub,

blades, swiveling elements, and spring means, of a shaft included in the impeller-driving means and affording the impeller a limited travel along the shaft to engage the blades with the margin of said opening for closing the opening, or to clear them from such margin for exercise of their impelling function, said driving means also including a pair of coacting clutch elements respecftively carried by the hub and shaft, operatively engageable or disengageable according as impeller travel along the shaft clears the blades from or engages them with said margin, and means automatically responsive to initial energization of said driving means for shifting the impeller along its axis of rotation and thus clearing the blades from said margin, and automatically responsive to deenergizaticn of the driving means for reversely shifting the impeller to seal the blades against said margin.

6. A combined impeller and closure as set forth in claim 5, the last-mentioned means including a spring urging the impeller along its axis of rotation toward sealing engagement with said margin.

7. In a combined impeller and closure of the type which is correlated with a member defining an opening for fluid flow, and which comprises a hub, a set of impeller blades outwardly extending from the hub, elements carried by the hub in a circum-ferentially spaced and approximately radial relation to the hub and establishing circumferentially spaced axes approximately radial to the hub, means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means on said hub and including means engaging said blades for urging the blades about said axes toward their closure position and driving means connected to the hub for rotating the impeller, the blades being centriiugally actuable about said axes to their impelling position responsive to a predetermined velocity applied by said driving means, the combination with said hub and blades and a shaft included in said driving means and affording the impeller a limited travel along the shaft to engage the blades with the margin of said opening for closing the opening or to clear them from such margin for exerelse of their impelling function, of means establishing orcutting off a drive from the shaft to the hub according as said limited travel of the impeller clears the blades from or engages them with said margin, and means for storing energy responsive to clearance actuation of the impeller and for employing such energy to shift the impeller to its closure relation to said margin.

8. A combined impeller and closure as set forth in claim '7, the hub being screwthreaded on the shaft to induce said travel of the impeller along the shaft.

9. A combined impeller and closure as set forth in claim 7, the last-mentioned means being a coiled spring interconnecting the shaft and hub and torsionally stressed in accelerating the impeller.

10. In a combined impeller and closure as set forth in claim 7, a device for retarding release of said stored energy until deceleration of the impeller has substantially relieved the blades of centrifugal bias.

11. In a combined impeller and closure as set forth in claim 7, a latch device automatically interconnecting the shaft and hub for rotation in unison in the impelling position of the impeller, and means for automatically unlatching such device responsive to recovery of the blades from a centrifugal actuation.

12. In a combined impeller and closure as set forth in claim '7, said means establishing or cutting off a drive including a drive element fixed on said shaft, a pin slidable on such drive element to and from the hub, the hub having an orifice to register with and receive the pin, a spring urging the pin toward the hub to enter the pin in said orifice, and means for ejecting the pin from the orifice responsive to recovery of the blades from their centrifugal actuation.

13. A combined impeller and closure as set forth in claim 12, said shaft having a portion in screwthreaded engagement with the hub, to effect said limited travel of the impeller along the shaft responsive to shaft rotation.

14. In a combined impeller and closure of the type which is correlated with a member defining an opening for fluid flow, and which comprises a hub, a set of impeller blades outwardly extending from the hub, elements carried by the hub in a circumferentially spaced and approximately radial relation to the hub and. establishing circumferentially spaced axes approximately radial tothe hub, and means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means on said hub and including means engaging said blades for urging the blades about said axes toward their closure position and driving means connected to the hub for rotating the impeller, the blades being centrifugally actuable about said axes to their impelling position responsive to a predetermined velocity applied by said driving means, the combination with the hub and blades and a shaft included in said driving meanssuch shaft having a portion in screwthreaded engagement with the hub to axially shift the impeller responsive to shaft rotation between an idle position of the impeller, sealing the blades against the margin of said opening, and an impelling position affording them clearance from said margin for impelling rotation and for swivel travel about said axes, of means including clutch elements on the shaft and hub for establishing or cutting off a drive from the shaft to the hub according as the impeller is at its impelling or closure-forming limit of said axial travel, inner and outer spaced sleeves fixed on the hub coaxially with the shaft, and a torsion spring carried by said inner sleeve and interconnecting the shaft and hub to store energy as the impeller is screw-fed by the shaft to its impelling position, and to screw-feed the impeller to its idle position by release of said energy upon cutting off the drive, said spring means swivelly urging the blades toward their closure position being carried by said outer sleeve.

15. In a combined impeller and closure of the type which is correlated with a member defining an opening for fluid flow, and which comprises a hub, a set of impeller blades outwardly extending from the hub, elements carried by the hub in a circumferentially spaced and approximately radial relation to the hub and establishing circumferentially spaced axes approximately radial to the hub, and means swiveling the respective blades on the respective elements for travel about said axes between closure-forming and impelling positions, spring means on said hub and including means engaging said blades for urging the blades about said axes toward their closure position, and driving means connected to the hub for rotating the impeller, the blades being centrifugally actuable about said 10 axes to their impelling position responsive to a predetermined velocity applied by said driving means, the combination with said defining member, hub, blades, swiveling elements and spring means, of a shaft included in said driving means mounting the impeller and affording it a limited sliding travel along the shaft to engage the blades with the margin of said opening or to clear them from such margin for exercise of their impelling function, said driving means including a pair of coacting driving and driven clutch elements respectively fixed on the shaft and hub to drive the impeller, such elements being engaged or disengaged according as the impeller is at its impelling or closure limit of sliding travel, and means carried by the driving clutch element for limiting swivel response of the blades to centrifugal force.

EMIL A. MADER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,779,084 Bergren Oct. 21, 1930 1,915,685 Mattson June 27, 1933 2,383,001 Mader Aug. 21, 1945 2,383,004 Mader Aug. 21, 1945

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