SG177949A1 - Combined ceiling fan and light fitting - Google Patents

Abstract

COMBINED CEILING FAN AND LIGHT FITTINGThere is provided a combined ceiling fan and light fitting (10) having blades (I - 4) that when the ceiling fan is not in use retract and are stowed above an enclosure (12) containing a light emitting device and that when the fan is in use are extended under centrifugal force. The blades are formed in such a way as to both stow compactly above the enclosure and provide reasonable aerodynamic performance. Each blade partially overlies a neighbouring blade when in its stowed position and the blades are so formed as to permit such stacking while limiting the overall height of the assemblage of stowed blades.

Description

i 8 © COMBINED CEILING FAN AND LIGHT FITTING

TECHNICAL FIELD

The invention desorbed herein minies tb a combinad Sgt fitting and - gelling fan having blades thal are compactly folded whe the fan is not In use anid that move eotwardly when the fan is started. Mors particularly the vention relates to improved fan Blades for such an appliance.

BACKGROUND ART oo : 28 Ceding fans have long been recognize and used as an nepenaiis © way to provide movement of aie within rooms of buildings. They can be simple fo uae and install, safe, and inexpensive to buy and wn when pomparad fo such alternatives as for example rafrigeraiad and evaporative alr conditioning units, They can offen provide a suprisingly affective alternative to air 2% conditioning as the sir movement they generate can evaporate skin - perspiration with 8 resulting cooling stfsch. © itis known to combine ceiling fans with lighting means, as firstly Riss sommon reqererment io provide oefing mounted Hohl sources, and secondly it is tonveniant to provide 8 single power supply fo operate a combined fon amd

C3 hob fiting. ; : : : © Less sommcey, | has also been known Wa provide a combined light fitting and ceiling fan with soma form of folding or retracting blade : arrangement. Le Velie has described three versiones, US Patent 1445402 discloses & ight iting and calling fan in which blades move outwards under 38 ventdifugal force when the fan i switched on, and are elracted by springs when the fan Js switched off. US Patents 1458348 and 2079942 disclose improved versions, in which {unlike the early version of Pateng 1445402) the inward and outward movements of the blades are synchronized.

Synghranizing blade movement is nporiant for prasendog satisfeciory balance of the rotating parts of the fan, Mare recently, a combined light fitting and celing fan has been disclosed by Villslia (ses infernational patent § publication WO 2007006088) with 8 concealed and simples blade movement synehronizing arrangement that lends itself to modern design,

A problem in the design of 3 combined fight fitting and ceiling fan is to provide blades that when in use can provide used ak faving performance without requiring excussive power and that when not it use can fold into a + 18 reasonably compact overall form. The present invention addresses this projet.

Referonces shove and slsewhera in this specification fo nertain patents ate red intended #8 of to be Inken as admitling that anything therein forms a part of the common ganaal knowledges in the artin sy place. - SUMMARY OF THE INVENTION © Ascombined celiing fan and light fitting will in ihis specification be + referred 10 as a fandight for convenience and brevity, ~The invention relales to andights having a plural ity &f fan bindes that move oubwandly fo operating positions during fan operation and inwardly to stowed positions when fan operation ceases, Movement of the fan blades putwardly may be by action of centrifugal force when the blades arg rotated about & fan-axis bya mater. Retraction of fs fan blades to their stowed positions may be by action of resilient means, for example one oF mare springs. Co 23 The blades are adamed and amanged when in their operating positions to move alr downward a8 they rolate, and when in their stowed positions fo fie within a defined radius from the fan axis, such as the radius of & ransiucent enclosure of circular form (when seen in plan view) for ight emitting devices

C such as innandescent lamps, Bach blade when stowed may overlap at least 38 one other blade, . Preferred forms and relative positionings of blades are disclosed that gre believed to provide a useful balance between the requirements of reasonable giv movement and compact swage of the Hades when natin © use. These forms are particulary chamclerized by conan distributions of incifience, Made chord {distance measuned from beading erige © nailing edge} and dihedral, They are prederably of serofol cross section with such camber

Hat iower blade surfaces are concave and upper blade surfaces convex.

More specifically, he vention provides in a first asapact 2 combined ceiling fan and fight fling having a plurslity of fan Diades, wherein: sah blade is pivotally mounted so as to be plrotaiie about an upright pivot axis of the blade betwen a slowed gosdion arid a deployed position - each blarie when in its stowed position les within a specified radius from an upight fan rotation ads and above a fight Wing podion and has at alr iH moving portion that inv the deployed pasion of the blade sidends beyond said specified radius; and each blade is generally slongsle and arcuate when seen in plan view and in its stowed ‘posiion extends peripherally within said specified radius between its pivot axis aod a tip end of he blade and partially ovetiies a 1 neghbouring ane of thes blades #1 Be own stowed posiiion; the combined celling fan and ight Biting characterized in that : 2) gach Made intially fees in height above a datum height with increasing distance along the inde from fis pivot axis end sé thal the bade when in its stowed position overlies the pivot axis end of the neighbouring 28 Made iris own stowed postion and : | : wth increasing distance from & privotaxis end of the alr moving partion fowards the tip end of the blade tha leading edge of the air moving portion first increases in height above the said datum height and then oo hums downwardly whereby to mit the height of the fip end ghove the 3 datum height : “The term “neighbouring bade” here means a blade that is first found by moving peripherally forward fie. in the direction of fan rotation} from one blade, | oo : The phrase “urns downwardly” here does not necessarily mean that with increasing distances towand the tip sof from such furaing dows the biade begins to actually descend, Rather i means that the blade noreases in height ata lesser rade than before the turning down, which may stil be positive although that is not to preclude a zero of negative rate of height norease,

Thus, the lead ing adyge of ts air moving partion of gach blade ay have a peak height above the datum height at a position between the pivot ads snd of the aly moving portion and the tip end of the blade.

Futher, the height above the datum height of the lading edge of the § ar movng potion may decline from said peak height with increasing distance along the leading edge foward the ip end of the Hada . : “The ‘spacified radius” may be approximately & radius of a light fitting oo portion that Is comprised in the combined cetling fan and loht Biting ang _ located below fhe blade and that is of olroular shape when seer in plan view, © The “deturs height” may, purely for example, be the height of an upper surface of a horizontal platelike member to which each of the blades is pivotably mounted as in the case of the constuction described by Villa,

The air moving portion of each bade may have 2 trailing edge that whan seen in plan view is approximately a cireular arc which when the blade isin is stowed position sald is substantially centred ony the fan rotation axis.

This avangement allows effectively use of the available space above a ight fitting portion thal is round when sesn in plan view, ;

C Prefoably, for gach Blade wher in Hs slowed position the radial distance between the leading and traling adges of the air moving portion : reduces progressively (Le. the blade tapers as seen in plan view) from a

To masivum vals pathway slong the length of the alr moving portion towards thebladetipend. - : : E

More proforably, when all blades are in thal stowed positions therels - for each blade 5 frst point en the ieading sdie of ts alr moving partion whem 2% ihe blade overlies iis neighbouring blade which frst pond wehimn seen nn a © notional radial plans including the fan rotation axis lies af a greater radius than 2 second point In the same notional plane that is on the leading edge of the overdain neighboring biade. Co : X

Le Still more preferably, the said first point may be al a height above the

RF datum height not exceeding the height of the said second point, © These arrangements san enhance the compactness of stowage of fhe “blades. oo oo oo it is prefered that the alr moving portion of sach blade hes in the oo deployed position of the blade a maximum angle of incidence 1© the horizontal at aposition partway along the air moving portion the angle of incidence decreasing wilh increasing distance from that position of man cidancy towards he tp end of the blade.

Preaferably alas, the alr moving portion has a posithve angle of incidence

Clothe horizontal of ds plvol-anis end, . The position partway slong the air moving portion of gach Made ®t which fis incidence to the horizontal is a maximum when the blade is in ite deployed position may be radially inboard of a position af which the blade chord measured along an are centred on the fn rotation axis is of § maxim 0 value Ris thought {bul not asserted) that this feature may smooth the distribution of downward thrust on the air along the Bade, so reducing induced drag oft the blade,

Although adaptable to other numbers of blades, for example three or

Sve, he number of blades is preferably four with the blades’ pivel axes being spaced 80 degrees apart from aach other peripherally, : : "That section of each blade between Hy pivot axis and Hs ip end when the blade is in He stowed position may sublend an angle of about 180 to 170 degress at the fan rotation ade. Values iy this range allow reasonable blade areas within the available stowage space above the light Biting portion, bu

In without at any point requiting the stsoking of more than two blades. This ausisls ir obtaining compact blade stowage. .

Fraferably, each blade pivots through an angle of sboul 180 degrees to move from ds stowed position is deployed position, This gives a satisfactory blade-seeept ares for a given blade size. : Preferably, the al moving section of each blade is upwardly cambeved {i.e convave downwards) between is leading and trailing edges when seen in cross-section on a cylindrical surface centred on the fan rotation axis snd intersecting the air moving section at a radius between the specified radius anid the Blade ip ered Ss

KEE His also preferred for efficient alt moving that the air moving section of seach blade has a roundad leading edge and a sharp trailing edge over at least pant of its along-tisde ength when sean it cross-section on & oylindrica) surface candred on the fan rotalion axis and inforseoting the air moving section at a radius between the specified radius and the blade tip end, .

The minimum height difference between each blade and its risighbouring blade when the bisdes are in thelr stowed positions may advantageously scour approximately where the blade overlies iis neighbouring blade. i an overlying blade sags slightly, ss may be the cass with Hades moulded from certain plastics # lo unused for some time, this arrangement has been found fo support the cuter part of the blades reasonably well one confact between a blade and iis undedying neighbour has been mada. oo po

The invention provides in another aspect a combined cailing fan and

Hy fight iting having a plurality of elongate snd arcuste plantorm blades that can rove pivotally about upright axes between Srstly stowed postions above a light Biting enclosure and secondly deployed positions in which the blades extend outwardly beyond the Right fitting, characterized in that leading edges of the blades whew in thelr deployed positions firstly tise with increasing 1S radius beyond the fight fitting gnclosure first and thereafter are cranked ’

Co downwardly, . fn this aspect, when the blades are in ther stowed positions gach blade overlies a part of its neighbouring blade which partis received in 3 gap shove the fight tting enclosure and below the underside of the overlying blade said

Wn gap existing by virtue of the cranked shape of the pvarlying blade.

Sach blade may be pivolally nownisd to a rotating platelike member with sab! gap ying above said platelise member, | Co in a thing aspect the irention provides @ combined ceiling fan and light fitting having air moving blades that in use exhibit gullwing dihedral, it is 8 thought that such 3 dihedral form may be advantageous iy itself sven apart from its ability to enable compact stowage of refracting blades. “Gulkwing dihedral” is io be taken as meaning thal a fling Made or wing rses Between

Hs root end aid a point of region slong Hs length pm its tip end sid then sither falls, remains level oF rises more slowly. oo a Cin a further sspent the invention providés a combined ceiling fan and ight fitting having a plurality of fan blades, wherein: sash ads is pivolally mounted so as to be phictable about an upright pivot axis of the blade betwean a stovend position and a deployed position;

each blade wha in its stowad position lies within & specified radius

Fron an upright fan rotation axis and above a light filing portion and has an air oving postion that in the dogioved position of the blade extends bevond sald specified radius; and : & ach blade is generally Jongate snd arcuste when seen in plan view with concave and convex sides and in its stowed position extends peripherally within sald speified radius between Hs pivot axis and a ty end of the blade, characterized in that {a} each hbisde when deployed is 50 positioned that 3 concave side of the 19 blade faces forward iy the blade's direction of rotation and so thats radially cuter portion of the bade’s tengih extends both cutwandly and

Co forwardly, : -

Co {) thers is » first position partway along the air moving portion of the bade al which the bade's chord as measured in 3 peripheral is direction has a madirmym value and 8 senond position partway slong he alr srcwing portion of the bade at which the bade has a pki positive angle of incidente tothe horizontal and {oy the first postions ats grater radius than the second position.

That is, the distibutions of inpidence and chord disclosed herein are believed advantageous in themselves apa from the issue of bisde sfowags.

The invention further provides a blade adepisd for uss in fendlights as disclosed. - ~~ 7 Ris expliclly intended that the specific our-blade embodiment described in detail below be taken to be 2 claimaebie aspect of the vention both as to the proportions of the blades and their relative positions when in their stowed and operating postions. : © The invention is preferably applied in fandights faving certain features of the construction described in Intemational Patent Publication WO

ROUTHI0OB0E (based on Intemational Patent Application No,

POTIAUZ0UBIO00881 by Jos Villella). C in a sill further aspect of the invention there is further provided a farvlight comprising a plurality of retractable fan blades, whats

} asavh said blade is pivotally mounted to a fan member that ls rotatable about an upright fan sofation axis so that sald blade is pivolaltie hotwesn a refracted position and an opening position about an upright blade pivot axis © of said fan member; 3 each said blade has an elongate and generally arcuate sir moving ade porlion tiat when said bladg 1a in the retracted position of said blade

Hes within 2 space bounded by: | oo a {®) sn inner cylindrical surface coaxial with said fan rotation sds and touching an hiner edge of said blade portion; © oo wa an outer syfinddeal surface coaxial with said fan rotation axis and . {touching an cuter edge of said bizde portion; fe} a fred radial plane containing said fan wotalion axig-and sald blade pivot ais) and oo {dy a second radial plane confaining said fen rofation ais and that touches i8 a tips of the blade, . no that associated with every point on said blade portion is an angle theta being an angle betwean said first radial plane and a radial plane containing the fan rotation axis and that point; and o within a continuous section of the blade portion that lies helwesn sald 30 first and second racial planes, said inner edge increases in height ahnve a dntuin height with incressing theta, and a radial projection of sald nner edge pote 8 oylindrical surface coaxial with sald {an rotation ais bs concave downwards, : :

Preforably, within said continuous uation of said blade said inner sdge moreases in height above said datum height with increasing theta until a maximum value of the ner gdge heights first reached at 8 point thereon whose value of thete Is less than the value of hele at the blade tip, yithin said oantinuous section and for theta values greater than the smallest value at which said inner edge has Bs maximum height above said datum height, the height of said inner sdge may decrease with increasing theta, This particular embodiment corresponds to the preferred ernbadimant described in deolail herein,

in such o fandight the other preferred fortunes proportions and meletive positioning of the blades ag dascribad harsin may also ba applied, including as to the blade Failing edge shape.

Further fastuns, preferences and inventive conoepls ave disclosed in § the following delalled description and appended claims. © inthis specification, including i the appended ollie, the word “comprise” {and derivatives such 8s “comprising”, “comprises” and

Ce Cpomgised”y when used in relation to & set of integers, elements or steps is

Cpt io be taker as presiding the possibity Sal other infeges olements or 18 steps are present or alle to be included. So

In order that the invention may bs belter undersinod there will now be deactibed, non-dimitingly, prafersd embodiments of the invention as shown the atached Figures, of which: : "

Figure { is a perspective view from above of a fandlight with retractable 15. fan blades according fo the invention, shown with Hs blades deployed to their operating positions; oe © Figure 2 is a perspective view from below of the fandlight shown in

Figure 1 with its blades deployed fo thelr operating positions;

Figure 3 is a perspective fram above of the fenflight shows in Figure 1, now with its fan blades shown in thelr folded, nonoperating positions;

Figura 4 is a perspective view from below of the fanflight shown in

Figure 1, with its an blades shown I their folded, nonapsrating positions;

Figure 8 is plan view of the fanflight of Figure 1, with its fan blades shows deployed to thelr operating positions; ) oo 3 Figure § is 8 plan view of the fanflight of Figure 1, wilh is fan blades showy in thelr folded, non-operating postions; oo Figure ¥ is a side view of the fandight of Figure 1, with ite fan blades shown deployed to they operating positions; ’

Figure 8 jo = side view of the fanflight of Figure 1, with is fan blades shown in thelr folded, non-operating positions,

Figure § i5 a perspective view from belbbw of a subassembly of fanflight with retractable fan blades described in Intemational Patent

Publication No, WG 2H7HB00S by Vitlelly;

i

Figura 10 is a schematic plan view of the fanfight shown in Figure 1 showing one blade in both deployed and retracted positions and the other blades in retracted positions and chaln-dotied lines only;

Figure 11 is a schematic plan view of the fanflight shove fn Figure § with all blades show in chain-dotied lines in retracted positions and one “Biade also shown in ity deployed postion the view further showing positions of a set of eyfindrical surfaces intersecting, and focated at rad ally spaced stations along, the extended blade: oo CL oo Figure 12 is 3 sof of sections {shelad a 1) on radial planes as defined in Figure 10 of retracted blades of the fandlight shown schematically in Figure 10; : : Figure 13 is u graph of heights above a datum height of inner and cuter edges oof 2 blade of the fanflight shown in Figure 1, as a function of circumferential position when the blade is in a redracted position;

Figure 14 is a graph of radial distance between inner and outer edges of 2 blade of the fandlight shown in Figure 1, as a function of circumferential. position whan the blades In a retracted position: ~~ Figure 18 is 8 graph of heights above a datum helgh? of inner and outer edges of all blades of the fanvlight shown in Figure 1, as a function of 28 cireurnfarential position when the blades are in their retractor positions:

Figura 18 is a set of cross-sections of the extended blade shown in

Figure 11 taken on planes tangential to the arcs shown therein an numbered tin 8; oo Figure 17 i 8 graph of an angle of incidence {io the horizontal of the 2% exdended tan Made shown in Figurs 11 as 8 function of radial position an the blade; 7 :

Figure 18s = graph of the chord of the eotended blade shown in

Figure 11 as a lunction of mdial position on the fade. ) DETALED DESC RIFTION OF PREFERRED EMBODIMENTS : 38 Figures 1 io 8 show a fanfight 10 secording 10 the invention. Farlight 18 hss a non-rotating powh-ike transfcsnt enclosure 12 in which fs mounted -at least one electric lamp (not shown), sd is supported from a calling by & tubular support 13 I known manner, Fandioht 10 also has Tan bledes 1.3.3 and 4 that are rotatable by an sleclric motor {not show) shot an upright axis it 1h somaal with tubaler support 13. The slectris motor and the lamp ars . operable separately or together from a source of electric power that is supplied through the tubular suport 13. The motor is of 8 known type, widely used in calling fang, that hae 3 rotating sidamal casing (not shown) with a § central cavity in which is received the Wwbuder support 13. Enclosure 12 is circudar in plan view, centered on mis 15

Blades 1 - 4 each extend otsbwardly to the operating positions shown in

Figures 1, 2, band ¥ when the motor is swilched on, and retrast gold) info positions shown i Figures 3, 4, € and § when the motor is switched off. The 16 senss of rotation is as shown by arrow 7. Esch one of blades 1 — 4 is pivotally supported on a blades support plate 14 that supports and rotates with blades ~4, i disc-shaped, fa coaxial with the rotation axis 10 of the motor and is secured to the mintors casing. A decorative dust cover 18 is secured on the suppoit 4 above the blades 1 — 4 whan thay are in the folded positions shown inFigures 3,4, Band B, :

Pivoting of blades 1-4 an blade support plate 14 ks respectively sbout axes 21, 23, 23 and 24 paral o the axis 15 of redation of the motor, When the moter is switched on, blades “4 pivot outwardly under the influence of ’ cenirifugal foros, piveling around thelr respective pivol akes 29 - 24, untit the 0 operating positions shown in Figures 1, 2, B and 7 are reached. When the ' sotor ia switched off, niades 1-4 ara retracted fo their stowed positions as shown in Figures 3, 4 8 and §, again pivoting about their fespentive axes 21 - 4. | | | :

Cin international patent No. publication WO 2007/00B008 (based on 2B Internationa! Patent Applisation Ma, PUTIAURONHOG0RET by Villalle), which is incorporated herein in ts entirety by reference, there is desorbed a fanflight genseally it sccordanos with the above principles and anrsngement, albeit with three bisdes instead of the fow blades 1 ~d of Fandlight 10. The present

Feention in its preferred ambaodiment is made in accordance with the 38 principles and arrangement set out in Villalis's disclosure save for the use of the four blades 1-4 instead of three,

In particular, synchronization of the pivoting movement of blades 1-4 and thelr retraction, may be by means of 2 simple adaptation to four biades of the ap proach disclosed by Villefla, now briefly described. Figure 8 {similar ©

: Figure F of Villefie's publication} shows a subassembly 30 of Villelle's fanfight comprising & motor 34, blade support plate 38 and wee blades 31, 32 and 33. (Mote: The tem numbers used herein to describe subassembly 30 we not ihe same as those used in the cled Villalis publication.) Blade support plate § 38 ring shaped and sscunsd fo motor 34 {of the oialing casing hype + previously mentioned) so as fo rotate therewith in ie own plane.

Secured below blade support plate 38 a sun gear 38. (The term “sun gaa is hors used gs & is in he at of so-called planetary gearing systems, where it rofers to a gear thal meshes with a number of ‘planetary’ gears 1 arrayed around Be periphery.) Sun gear 38 is somal with the moter 4 when support plate 38 is mounted fo mole 34, and is able to rotate about is axis ralative to support plate 38. Meshing with sun gear 38 are planstay gears 41, 42 and 43, each of which rolafes as is associated one of blades 31-33 pivots between is stowed and opersting positions, Each of gears 41-43 6s secured 10 a sho shalt {not visible} that passes downwardly from iis associated one of biades 31 - 33 and can rotate within support plate 38. The gears 41-43 are equispaced ground the periphery of sun gear 38 and are themselves all at the same radius ae each ther from the rotation axis 35 of ’ motor 34. The effect of this srmangement & thal provided blades 31 «33 are identicad and dentically positioned in thelr working positions relative to support ’ piste 38, they will be apt synchronized always when they phat between thelr operating and refracted positions. CL

To retract blades 39 - 33 when motor 34 ie switched off, oll springs 44 are provided. One end of sah spring in secured fe 8 formation 48 depending 28 from support plate 38 and the other and is secured to a Remation 48 depending fro sun gear 38, Coll springs 44 are arranged to ba intension when Blades 31 - 33 are in their wiracted position and sre extended as oo centrifuga! foros urges blades 31 - 33 out when motor 34 is started. When motor 34 {8 stopped, springs 44 urge sun azar 38 to rotate relative to support plate 34 80 as to retract ihe blades 31-33.

For further information on, and options relating fo, this amangement for blade synchronization and retraction, refer can be made to the cited publication of Vilketla,

The way to adapt this arrangement to the four blades 1-4 ofthe ambadiment of the present version here described will be readily appamnt fo persons skilled in the art. There would be povided four planetary gears {rx shown, but eauivalont fos gears 41 —~ 43} instead of thise, equispased $ around the sun gear {not shown, but equivalent fo sun gear 38) and aach ‘associated with one blade. ir the fotloving descripfion, # will be assumed that blades 1 ~4 ars

C pivotally mounted to support plate 14 essentially similar to support plate 36 and synchronized and retracted in the seme way as blades 31 ~ 43 of subassembly 30. However, it is emphasized that the asrodynamic design of blades 1-4 and the way that they “nest” together when retracted are by no meany miedo this particular fanflight construction. The pordigunation snd arrangement of blades 1 ~4 could be applied to fanlights of other constructions and to fans requiting relraciable blades and withoud sny lighting 18 ceopabiity :

Co The blades 1-4 and thelr sirangement in Sardlight 10 will now be described. Blades 1 dare intended to provide fandight 10 with a sell hatance between satisfactory ait-moving performance, compaciness when the

Blades are in thelr owed {i.&. refracted or folded) position, together with a

HY diameter of the ranstuoent enclosure 12 that fs large enough fo provide a reasonably diffuse Sghting sifect. The blades 1 - 4 are intended to He substantially above the transiucent enclosure 12 when retracted. Inthe smbodiment show sd desuribed herein, the snclosure 13 has a diameter that is shout 38% of the bverall diameter of fanfight 10 with is blades 1-4 extended for operation. The diameter of the hub of a conventional calling fan of farflight without retractabde blades & iypically smaller than 38% of the wvarall diarmster over the blades. The larger the diameter of enclosure 12 fore given overall diameter, the easier tis fo meet the remarement of compact folding, with blades 1-4 above enclosure 12, bul ihe more difficult it is to 10 provide satisfactory air moving performance at normal far rotational speeds.

A rangs of from about 368% to about 42% for the above ratio is believed fo be possible by straightforward adaptation of the blade shapes as desoribed © herein, but a figure in the region of 38% to 40% i» prefered.

i

Tha geometry of Hades 1-4 will be desoribed below by reference fo quantities and sections defined in Figwes 10 and 11. In the schematic plan view of Figure 10, anvlosurs 12 is represented simply by ite clrcular oiter peripheral edge 76. Blades 1-4 are all ghown in sulline in their retracted positions, blade 1 in solid lines and the others In chain.dotted lines, and blade © 4 is also shown in solid ines ib Hs deployed position. Blades 1 4 Je substantially identical to sach other and are generally scimitarshaped, Le. of srouste kim so as le, when retracted, within the enclosure peripheral sedge =5 and around the motor {not shown bit centred on 8s 18%, The pio axes 21-24 are adjacent fo root ends $1 — 54 respectively (Figure 11) of blades 1 — 4 ard in their retracted position the blades 1 — 4 extend lnckwise to fing {free ands) 81 ~ Bd respectively, Ham numbers with the pusteoript “8” ane for blade 1 in Bs deployed position and Rem numbers with the pastsonipt “b> are for blade 1 in its retracted position.

Blades 1 ~ 4 of fanflight 10 are shown (by arrow 7) as rotating clockwise when seen rom shove. itis 0 be undersiosd ROwWERET, thst counterclockwise mation could equally well be chosen, in which case the term “counter-slnckwise” would be spplicable where in the present description “slockwize” now appeaTs, inclading in he definitions giver below of the terms “next blade” and “previous blade”. (Note that for coumter-clockwise rotation, © the blades would be made of opposite hand to blades { ~ 4, as # is prefered hat each blades leading sdge be Hs concave one.) : in relation fo any given ane of blades 1 4, the enn “next blade” refers oo to the blade whose pivot axis fs 50 degrees in tha rotation discon ere 2% clockwise} from the plynt axis of the given blade, and the lem “previous blade” refers to the blade whose pivot axis is BO degrees in 8 counter dirastion opposite fo the rotation direction {Le sounterglochwise hare) from the pivot axis of the given blade. Thus, in relation to blade 1, the next blade is

Blades 2 and the previous blade is blades 4. The blade shape will be desorbed mainly by redarance fo blade 1 for conveniences, noting that blades 1 — 4 ate substantially identical. Co oo To show how blades 1 ~ 4 are arranged lative to each other in nesting fastion when refracied, # will be convenient tn use sectional visws on racist planes, Le. planes that Include the fan axis 15, Such a plane 42 is shown in

Figlre 10 and is shown jo be at an angle 8 (thetriio a similar plane 44 that includes both axis 15 and axis 21 of blade 1.

For discussion of the Dade shape from the point of view of aerodynamic charscteristios when in the deployed position, # will be useful fo § consider blade sections faken on sutfaces that are aylindrical, coaxial with fan axis 18, and located at stations radially spaced apart slong a blade. Arcs © numbered 1 to 8 in Figure 11 indicate such stations on blade 1. Stations 1 and 8 are respoctively at vad of 38% and 37% of the overall fan radius (Le substantially at the adgs of enclosure 12) with stations 2 ~ 7 radially 19 sypdspaced between stations and 8,

Each of blades 1-4 pivots through 180 degress bohvesn Hs relracted and opemiting positions. From axis 21 to tip &1, reprosanialive blade 1 when retracted extends from thete = 0 degrees fo theta = approximately 168 degrees. The angle 168 degrees is chosen to be close fo, it below, 180 dagress so 8% provide a blade 1 whose fir 8 is well olesr of enclosure peripheral edge 38 when binde 1 iv deployed, but with ne more than two of blades 14 overlapping each other al any point when the blades are retracted, This is important in keeping the overall height of the group of blades

Tod when retracted, os compactly small value. Note that if Hip 8% where at 26 theta = 180 degrees, all three of blades 1, 2 and 3 would overlap at eta = © 180 degrees. : oo

Ags can be geen in Figures 4, Sand 7, representative bade 1 has wo distinct podions, namely a roobend portion 80 and a blade portion 82 which in the operating position eidends outwardly of peripheral adge 26 of enclosure 23 12 and kk aerodynamically shaped io faciitste al movement. Blade portion 82 is supported cantiever-fashion from blade portion 80 which is pivotably secured to blade support plate 14. In the prefered embodiment, portions 80 amd 82 are formed gs a single pat, for example by infection molding in a suitable plastics material. 36 ~~ Rootend portion 80 comprises a plale 84 that lise above and, spprosimately parslisl fo support plate upper surface 48. Ahole 80 in phate 84 © permits a stub shaft (not shown) to pass through B and Swough fo the underside of support plate 14 {o be secured there fo & planed gear {not shown} of the hisde synchronization mechanism as desorbed previously. Root and is portion 80 further comprises a blade end plate formation 88 whose function is to provide a sullably strong sonnoation bebwaen portions BO and 83 with ‘binde © portion 32 inclined at an angle of incidence 10 plate 84 (soe below).

Figure 12 shows a sel of 12 radist sections (Ls. on planes 421 of representative blade 1 and ¥8 next and previous blades Zand 4d intheir " yetracted positions, each section being labeled with is comect value of theta for hinde 1, Radi from fan ads 18 homase ko fhe right in sections (& io i). In each section, blade support plate 14 is shown, with ite ouler edge 80 atthe same lateral position on each pags fu facilitate comparison betweenthe i¢ sections. Guler edge 80 es radially Just within but is Slose fo'the enclosure petiphers! edge 26 {not shown in Figure 12)

Sections (a) to {c) of Figure 12 show how portion 86 of blads 1 transitions to the tantilevered alr-moving portion 82.

As pan be best seen In Figure 10, cuter adge 8d ofpotion 82 of + representative blade 1 is very close io a ccular aro seep! near the rounded lip 84, that are being cenired ory fan axis 15 when blade 1 is rotracied and having a radius very close to the tadius of enclosure peripheral edge 26.

Accordingly outer edge 84 of portion B2 of blade 1 ies at almost exactly the same radius as the outer edges of next and previous Blades 2 and 4, except 2 near tip 81, as shown in sections {d) fo {) of Figure 12, oo

Figure 10 and sections {a} to {i} of Figure 12 show that previous bisde 4 overlies representative blade 1 between theta = O degrees and slightly fons than theta = 80 degrees, but without contact between hades 1 and 4.

Between theta = $0 degrees and theta = 168 degrees {sections {Qs 8) 43 Made 1 ieplf ovediss next blade 2, withow! contact betwesn blades and & oo Figure 13 Is 2 graph showing the heights of inner edges 92 and outer edge B4 of representative hizde 1 above surface 48 of support plate 1d as a function of angle theta, Inner edge 82 is higher than outer edge 94 for a given vale of theta, consistently with blade 4 having an angle of Incidence io the 3G horizonial 50 as to move alr downward when deployed (see below). Absolute hight figures sre used in Figure 13, ky a fandight 10 having an overall swept diameter with blades 1 ~ 4 deployed of 1200mm :

Figure 14 1s a graph showing the radial distance belwean ner edge 92 and outer edge 84 of representative blade 1 whan in its refracted position i7 as & function of angle theta. Absolute radial distances ame used in Figure 13, © fora fanflight 10 having an overall swept diameter with blades 1 — 4 deployed of 1200mm. The curve between data points has nol been sxiended lo the data point for thete = 165 degrees because that paint is affected by rounding $s oftip at: © Figure 15 is a graph showing the same data as Figura 13, but now for © all of blades 1-4, ivihedr respective peripheral angle {thels) positions, The initiate “LET and “TE” are used for inner and outer adues S2 and 84° respectively in Figura 15, because the inner edge of 8 bisde i» fy leading if edge and the outer adge i Ha frafling edge, whan inn the deployed position,

Note that the bade plvel axes 24, 88, 23 and 24 are af angles theta of © "degreas. 80 degrees, 180 degrees and 270 degrees, reepactively.

Figure 12 + 18 together Hlustrate how blades 1 ~4 in thelr retracted positions “nest” compactly logsther without any two blades contacting each ober hax baer found that the arrangement Shows can also ghee salisfactory air moving performances, ©. As Hiustrated by the edge heights in Figures 13 and 15, representative hiade { rises smoothly from He pivot axis #1 {at theta = 0 degrees) fo a point {st about thea = Qn dagrees) where it must everten and dear the rex blade 2 However, instead of continuing further upward st the same rate towards fis fin 81, biade 1 ceases fo dese any higher, as shown by the leveling off and then decreasing of the height of inner edge 92 with increasing thst: This grrangement mils the overall beight 86 (Figure 12) above support plate tH of the group of blades 1 +4 when retracted, The main value of hinight 88 ocours for representative blade 1 stabout theta = 108 degress. will he noted in Figure 13 and 15 that, alter remaining approximately constant between about theta = 80 degrees and theta = 120 degrees, ouler edge height BY Inoreases again beyond about theta = 120 degrees, As can be seer from sections §) to (} in Figure 12 , and from the slight protrusion of 39 Blade 1 shown in Figure 4, this optional feature means thal some alight sacrifice of compactness in the Blade nesting amangement is insured (although without any increase in overall height 88) tis helleved tobe aerodynamically desirable, as set out later herein, amd so is prefered.

i%

Figure 13 can be interpreted as a partial ploture of blade 1 as would appear if projected on an imaginary oylind tical surface comdal with fan ads, with that surface then being laid flat. His apparent that blade T insuch a : picture resembles a gull wing, or an alroraft wing with a partintdar fay of varying dihedral, firstly rising with Inoreasing distance from is root end and from a certain point rising no further or al 8 lesser ral towards its tip end,

Figure 18 shows that the hiner edgs height 82 of reprasentative blade 1 becomes lower than the leading edge height of #s next blade 2 for values of thet grester than about 150 degrees. This can be sean in sections 1 {ky and (I) of Figure 12. Jf dows not mean that thers is contact betersarn blades 1 and 2 beacause the reduction in radial width of blade 1 nopans that nner edos a2 of inde J is cactially outward of the corresponding sdge of blade 2, freaddifion to folding neatly, Hie blades 1 ~ 4 must move alt downwards reasonably sfficiently whan deployed and sedating about fan axis 18, so the (5 shapes of blades 1 — 4 as they affect alr movement will now be discussed.

The ares in Figure 11 thal are numbenad 1 8 represent a sat of spaced apart pylindrical surfaces coaxial with axis-18 and radially spaced apart. Although the downward sir flow through fandight 10 will notin general be precisely aad {Le parallel to ads 15) and therefore ovour on such swiaces, 8 reasonable

MW way to discuss blade shape is by reference to the intersections with the cylindrical mufanes 1 8 of represeniative blade 1 when nits deployed postion. it is alse helpful in the following discussion of the representative blade 1 when i is deployed by make mention of values of the angle theta thatwss used above in describing Hs geometry when retracted. Theta is inefferta © measure of position along the suimitershaped blade 1 In Figure 11, there is shown a non-physical point 101 that I blade 1 were to be refracted would fall on axis 15, and that when blade 1 is deployed is displaced by 180 degrees from axis 18 about the blade pivot ade 29. The value of angle theta

WW oorresponding toa particule feature on deployed bade 1 can be found asing the schemalio plan view of Figure 1 by constructing Hirstly a fine joining point

C101 tothe feature in question and secondly a line 104 joining point 101 and passing through axes 21, 18 and 23. Theda is the angle between these hwo fines.

Figure 18 shows cross sectional views of blade 1 luken on ehords 100 {see Figure 10) that are tangent to the oylindrivel surfaces of stations 1 08,

These are close approximations fo the shapes of the cylindrical surfaces of intersection between stations 1 to 8 and blade 1, as those surfaces would § appear Haid fal, in the sections of Figures 18, blsde 1 moves sight {0 ef}, so the leading sdge 82 and tailing edge 94 are positioned as shown, Although traffing edge 54 is of course not straight in reality, the views In Figure 18 ard 0 positionad that the failing odge 84 in all sections is vertically afighsd to + facilitate comparisons among then. So : 19 © Figute 17 is a graph showing alpha {), the angle of incidence to the horizontal of representative Made 1 af slalions 2 10 B, the meaning of alpha ’ being lustrated in the section for station 7 in Figure 18. The values of sipha pleted in Figure 17 are not taken from the approximale seoliens of Figure 18, hut are estimates of the values that would be obtained in the manner shown 15 the sections of Figure 18 were laid-fat developments of the true swiaces of intersection between the cylindrical surfaces numbered 2 to 8 and blade 1.

Figure 18 is a graph showing values of the true chord {Le distance messured directly from leading edge 82 io falling sdge 84) of bade tat intersections with the ovlindrical surfaces munbered 1 fo 8. The chord values 20 are not taken from the approximate sections of Figure 18, but ars estimates of the values that would be obtained i the true surfaces of intersection bahvean blade 1 and the cylindrioal surfaces numbered 3 to § were obtained and eid fist. So xy - . it has heen found that fanfiain 10 with Mades 1-4 having the geometry shown does move air ressonably selisfactorlly despite the comparatively args ratio of the dismeder of encloses 12 to the overall : diameter swept by the deployed blades 1 ~ 4 and the scimitar-jke shape {in plan view) of the blades. = . =

Lo Generally, the blades 1-4 thrust air downward (and themselves experisnue 8 cormesponding reactive fing force) as they rotate. The eifactiveness of 2 hiade in this or a given speed of rotation) is beloved to be dependent on, al least, Ks aerokildyps cross ssoonal shape, its idence to the horzontad, Bs size for example its chord as measured from leading edge

0 to railing wedge), the distribution of these sfong the blade’s length {span and its shape 35 seen in plan view. - ; As saan in the cross-sections of represerdative blade 1 in Figures 18,

Hades 1 4 have an serofoil- ype cross-sactional shape, being cambered so 57 that their lower faces are concave and thelr upper faces are convex, Their inading edges {ey leading edge 52 of representative Made 1) are rounded and thelr walling edges {eg sdge 84 of representative blade 13 ave sharp.

Generally, blades 1-4 are preferred 1 have cambered aenofolf sections. ©

Representative blade 1 hes positive incidence to the horizontal {and is 1 of camberad aerofoll cross-section) near is pivot end where, when deployed, - Rorosses the enclosure peripheral edge 28, and this is believed to be one factor in Ba air-moving perdormance. This positive incidence (slpha greater than sere} is appent in the section numbered 1 in Figure 18. : i ts thought desirable that the IR distribution (and the consequent distribution of sir moving effect along the length of a blade should be generally smnothiy varving and in partioudar that there should be no strong concentration of the effen! close to the outer {ip} end. Such a concentration ix thought fo produce a tendency for high pressore air below the ip area te feak® upward over the tp end {81 in representative blade 1) lo the Arca : above the ip ares, merely agitating the air focally (and wasting power rather fran moving #4 bodiby downward. Therefore, the distribution of inokienos angle alpha shown in Figure 17 shows that the peak blade Incidence of about 20 degrees is af about the radius of siation 3 {see Figura 11) and smoothly decreases with increasing radius to about 10 degreas at station 8. {Station 3 28 corresponds very approximately fa theta = 80 degrees}

The incidence distribution shown ins Figure 17 is dus inpart tothe optional upsweeping of the blade railing suge beyond about theta = Re degress that was discussed above. Although a shighily more compact nesting of blades 1-4 is achievable If fs upsweeping is not incorporated, i does 30 appearfobe beneficial to the blades’ performance due to its effect on the incidence distribution achieved. So co A further wavy io influence the iif distribution slong the bade fs by contrel of its width {chord) distribution, If one imagines a scimitar shaped blade of constant with slong fis length for example Tor all values of the theta)

deployed in the way shown for blades { 4 in Figure 14, an effect of the scimitar shape would be that the Iiade chord, as measured 0 the ) circumferential direction with the blade deployed, would be highest st the blade tip and root end and lower thansbetwean, To oifsal this effect and 5 lini the tendency fo concentrate the Biting effect at the tip and root ends, “blades 1-4 are not of constant width. Referring lo Figure 14, the blade width 8S seen in plan view) ie greatest at about theta = an degrass and

Co progressively redisces towards the Hp end (81 for representative blade 13. 8s oan he seen ins Figure 11, thets » 90 degrees corresponds approximately io ¢ sistion 8. This reduction serves the dual purposes of compact nesting of the

Hades whan retracted {as discussed above) and oblaining the desired blade if distribution, | .

Figure 18 shows the blade chord increasing from a minimum in the region of slations 2 and 8 before Talling away & station 8 due to tip rounding.

However, the rate of increase in chord with radius is less than it would be i the blade width did not vary with angle thefa in the way described hersin, See sles Figure 16, where the alignment of the sections numbered To Bon the : pags alfows the disidbution of chord with radius to be sen.

As mentioned shove the blades may be made conveniently by injection 20. rosiding in sultable plastics materials. As unobirusiveness is 8 desired feature of fardlights according to the invention, cue way of enhancing this is fo provide that the blades be formed from a transparent or at least translucent material

This feature is believed to be inventive in itself.

Although the blade stowage arrangement and method desorbed herein 2 provides for stowage of the blades without contact bebresn Hades, the described stowage positions of the blades are such that slight sagging of one blade so as fo contact anther may not cause faliure to deploy. i will be noted in Figures 12 that the sectional view showing the smatlest clearanve between biade 1 and its next blade 2 is section {g), corresponding to theta = 80 30. degrees. This is thought to be a suitable position for mirdmum dearance and so for first contact betwsen blades 1 and 2 to occur i after a period of stowage without fan use, blade 1 should sag slightly. i is thought that after sush contact between blades 1 and 2, the tendency to further sagging would be limited and the moment am about axis 21 of any Friction foros dus to Blade contact less than for contact belween tip 81 of Blade 1 and the underlying blade 2, this, limiting the possibility of a faflure of blade 1 to deploy on fan startup.

The possibility of blades that are comparatively thin {so that they may sag over time # not used) also means thet the blades when in LSE Tiy fsx © upwardly toward their io ends. This car His believed advantageously dives ot air slightly more oulwardly as well as downward ¥ than § the blades were rigid.

The particular shape of the ransiugent pws section Sof enclosure 2 is by no means the only possible one. Even a shape that is not of the circular 0 shape in plan, as shown in the Figures 1107 ould be used as an allemative aesthetic choice, CL Co

C Aturther invention will now be disclosed. In fanfights such as those

Bh i described by Wilistla In his aforementioned PCT application, the “sun gear’ © may comprise a single member to which toothed segments are secured for 1% engagement with he “planst gears’, instead of @ corrplate gear, This possibility, which § has been found can reduce manufacturing costs arses oo beacause suitable sun and slanet gear praparfiens can be chosen which do not require the sun gear to rotate far ensugh during deployment and mefraction for ary ons tooth thersof to encounter more than ong planst gear. am it will be readily spparent fo persons skied in the art that many other variations and choles can be made {0 the fandight described above without exceeding the scope of the invention as stated.

Statements of invention

1. A combined ceiling fan and light fitting having a plurality of fan blades, wherein:

each blade is pivotally mounted so as to be pivotable about an upright pivot axis of the blade between a stowed position and a deployed position;

each blade when in its stowed position lies within a specified radius from an upright fan rotation axis and above a light fitting portion and has an air moving portion that in the deployed position of the blade extends beyond said specified radius; and each blade is generally elongate and arcuate when seen in plan view and in its stowed position extends peripherally within said specified radius between its pivot axis and a tip end of the blade and partially overlies a neighbouring one of the blades in its own stowed position;

characterized in that:

(a) each blade initially rises in height above a datum height with increasing distance along the blade from its pivot axis end so : that the blade when in its stowed position overlies the pivot axis end of the neighbouring blade in its own stowed position and

(b) with increasing distance from a pivot-axis end of the air moving portion towards the tip end of the blade the leading edge of the ‘air moving portion first increases in height above the said datum height and then tums downwardly whereby to limit the height of the tip end above the datum height.

2. A combined ceiling fan and light filing according fo claim 1 wherein sakd specified radius is approgimately a radius of 8 ight iting potion that is vompdsed in the combined ceiling Tan and light Sling and fooatad below the blade and that is of circular shape when seen in plan

ViGW. . -

A, & onmibined osiling fan and light fitting according tonlagin tar 3 wherein the leading edge of the alr moving pation of each bisde has a peak height above the datum height at a position between the pivol- 1G wis and of the aif moving portion and the tip end of the Made. 5. A carnbined celling fan and light fling socoeding to claim 3 wherein the height ablve the datum height of tw lading edie of the alr moving portion declines from sald peak height with increasing distance along 5 the leading edge toward the tip and of the Diade. : 8. A combing ceiling fan and light fitting sceording to any one of calms 1 104 wherein the alr moving podion of sach blade has g frafing edae that when seen i plan view is approximately a circular are which when 28 ihe blade is in iis stowed position said is substantially canired an the fan rotation sxis. 7. A combined ceiling Tar and igh! flting according to cial § wherein for each Mads when in is stowed position the radia! distavios betwsan the 23 leading and railing edges of the alr moving pordion reduces progressively from a maximum value partway along the length of the air moving portion towards the blade tip end. 8. & combined ceiling fan and fight Sting sceording © claim § wherein whan af blades are in their sowed positions there is for ach blade a first point on the leading edge of is alr moving povion where the Made overlies iis neighbouring blade which first point when sean ing hotions radial plane including the fan rotation axis lies al a greaier radius then a second point in the same notional plane that is on the leading edge of the overlain neighbouring blade. 8. A combined ceiling fan and light iting according to claim 7 when the sald first point 1 81 8 height above the datum height not excesding the

Beioht of the said second point. 8. A combined ceiling fan and Bight fitting according to any ene of claims 1 to 8 wherein the air moving portion of each blade has in the deployed 14 position of the blades a maximum angle of incidence to the horizontal at a position parbway along the alc moving portion the angle of incidence decreasing with increasing distance from that position of maximum incidence fowands the tip end of the blade. 1510 Acombined ceiling fan and light fitting according to any one of claims 1 to & wherein the air moving portion has a positive angle of idence to tha horizontal at ile pivot-axis end. 1h Acombived veiling fan and fight filling according to claim Sor 10 0 wherein the position partway slong the giv moving portion of sash bade at which ifs incidence to the horizontal is a maximum when the blade is in ita steploved position is radially Inboard of a position at which the blade chord measured along an sre candred on the fan rotation axis is at a maximum value, 35 oo 12. A combined celfing fan and light fitting according to any one of clams 1 fo 11 wherein the aumber of blades is four and the blades’ pivot axes are spaced 00 degrees apart from each other peripherally. ; 130 Acombined osiling fan and ight Biting according 0 clan 12 whersin : that section of each blade between its pivot axis and Hs tip end whan the blade is In He showed position sublends an angle of shout 16010 17¢ dagress al the {an rotation axis.

C26 14. A combined ceiling fan and fight Siting ascarding to claim 12 or 43 wherein each blade pivots through an angle of about 180 degrees in move from fe stowed position to ifs deployed position, 31 Acombined calling fan and light fitting according fo any one of olaims 3 io 14 whersin the alr moving section of each Made Is upwasdiy sambsred (Le ooncaee downwards) between #s loading and traling adges when stn in oross-section on 8 cylindrical surface centred on the fan rotation axis and intersecting the alr moving section st a radius 1 between the specified rontiue and the blade fin end. 1H, Acombingd calling fan and light fling socording to-any ong of claims 4 to 18 wherein the gir moving section of wach bade has a rounded leading edge and a sharp trailing edge over st tens! part of is along “13 blade length whan seen in cross-section on & oylindrical surface centred on the fan rotation axis and intersecting the alr moving section at 8 radius between the specified radius and the blade tip end. 17. & combined calling fan and light iting according to ary one of claims 1 to 18 wherein the minimum height difference between pach blade and {a neighbouring blade whan the blades are in thelr stowed positions sours approximately where the blade overlies its neighbouring blads, 1. A combined oping fan and light fitting substantially ag disclosed hemi 23 by reference to Figures 101018 18. A blade for 3 combined ceiling fan and fight fitting substantially as disolosed herein by mlerence to Fgures 100 &0 20. Agombined cefiing fan and fight fitting having a plurality of elongate ard arcuste planionn biades thal can move pivolally about upright axes batween firstly Stovsd positions above a light filing enclosures and secondly deployed positiony in which the blades exland outwardly beyond the ight fitting, characterized in that leading edges of the hindes when in their deployed positions firslly rss with insreasing radius beyond the ight Riting enclosures first and thereafier are cranked : dowrmwandiy. 21. Acombined colling fan and light filting sccording fo claim 20 wherein + when the blades wre in thelr stowed positions each bade overlies a part of its neighbouring blade which pari is received Ina gap above the fight filting srclesure and below the underside of the overlying blade said gap existing by vidus of the — shape of the overving blade, iL : 22. Acombined ceiling fan and fight iting according to claim 20 or 2% weherain each blade is pheatafly mounted {0 8 relating member and sald gap Hes above said platelike maniber. 13 23. A pombined cefliing fon and Sght Siting having aly moving blades that in sae exhibit gulwing dihedral 24. A combined ceiling fan and ight fitting having plurality of fan blades, wherein: | a each blade is pivotally mounted so 8% 10 be plectable about an upright pivot ais of the blade betwasty 2 slowed position and a deployed position,

XE aach blade when in Hs slowsd position lies within a specified radius from an upright fan rotation axis and above a light fitting portion and has an alr moving porion that in the deployed position of the bade sxiends beyond said specified radius and } 34 gach blade i genorally slongale ard arcuate when scan in plan view with concave and convex sides and in #8 slowed position extends peripherally within said specified radius bebvoen its pivot axis and a lip end of the bisde characterized in that {8} sach bisde when deployed 5 so positioned that 8 concave side of the blade faces forward in the blades direction of rolation and 3 a0 hat a radially outer portion of the biade's length extends both outwardly and forwardly, : {hy there is a frst position partway along the air moving portion of the blade at which the blade's chord as measured na 10 peripheral direction has a maximum value and a second position partway along the air moving portion of the blade at which the blade has a maximum positive angle of Inoldence to the horizontal and fo} the first position is at a graster radius thar the seooad position, 25. A combination ceding fan and light fitting comprising ¢ plurality of retractable fan blades, wherein: sach sad blades is pivolally mounted to a fan mewber that is 2 solatable about an upright fan rotation axis so that said blade is pivolable between a refracted position and an operating position shou an upright blade plot axis of said fan member; each said bade has an elongate and generally arcuate air moving blade postion that when sald blade is jo the retracted position of sald blade es within a space bounded by: {sp sn inner oylindrical surface coaxial with said fan rotation axis aud touching an inner sdge of said blade portion; : 33 ib an ouler oviindrical surface coaxial with sald fan rolation axis and touching an outer adgs of said blade portion; fo} & firs! radial plane containing said fan rotation axis and said blade pivot axiy and ;

{= eccond radial plans containing suid fan rotation ads and that wiches a tp of the blade, so that sasociated with every point on sald blade porfion an angle theta being an angle between said frat radial plane and a radial

S plane cantalning the fan rotation axis and that point; and © within a continuous section of the Made portion that lies between said first and second mdind planes, said — adie Moreases in height above a datum height with increasing thets, and 8 radial projection of said inner adage onio a oylindnical surface coaxial with said fan relation xis is concave downwards. 28. A fan blade adapied for use in 8 combined calling fan and light filling according fo any one of claims 1 0 28. 18 27. A fan blade according fo claim 28 that is sufficiently flexible to bend upward towards te Hp and when used in a selling fan.

Claims (1)

1. THE CLAIMS DEFINING THE INVENTION ARE AB FOLLOWS : i A combined ontling fay sud light tsi faving a pherality of fade, wheel : gach blade ix pivotally mounted 80 ag 0 be pivelabie bot ¢ blade pivot axis 3 between a stowed position and » deployed position sach blade, whan {nite stowed position, Hep within o apcoified radius fron 2 fn rotation wis and shove a Hebt fining portion and has an alr moving portion that, in the . deployed position of the blade, cxionds beyond said specified radius wd such blade hes 3 root sod, dip, leading sedge snd ailing odge snd wherin the ; 1 loading wige io stepped apwedly of» location adjacent to ite rot end and then more graduslly invroases bo hefght in» diesation tevwadds is Hip. : 2, & fhaing ax olsbmed br claim 1, baluding an elects motor coupled 10 Blade sopsont means which, ruse, Brotatad by terete shout sald fan totation aude, ech of Be blades $5 being seppored by the bade support meng and mounted for yotaiton about fig hinds piver axiavelefive to the bisde support maar and whersin te blade spport reewna has « olvsular cuter peripheral edge mad wherein the trailing sdgav of the blades sre scdiacent 10 said ower peripheral adge when the blades sre in thelr stowed pogiiiong, 3 & Gdfiag as clabmed in olalm For 2 whershvthe Jrating sdpes of the Wadeg are © rounded: -

   4. & Siting ag olairosd nr eladm § 3 or 3, wherein the poo! end of such binds inchedes plate portion adfacont {othe stepped leading sdge ind wherein te railing adie of ach blade merges into of lowst part af an outer edge of the plate partion, Se 4 Btlog as cladoed by any one of elem io 4, whershy 6) the leading adpe of cach Blade resches x nario height than desvrases I : gr soveands Hs tpg addins : $y cack of the blades iv integrally moulded from Plastics material.