Combined light fitting and ceiling fan
A combined ceiling fan and light fitting (fan/light) ( 1 ) having folding fan blades ( 12 ) is provided. The fan light ( 1 ) has a blade support ( 13 ) arranged to be rotated by an electric motor ( 6 ), with blades ( 12 ) being secured to the blade support ( 13 ), a root end of each blade ( 12 ) being pivotable between folded and operative positions about a blade pivot axis-( 14 ) fixed in the blade support ( 13 ). In one aspect of the invention, an improved mechanism is provided for synchronizing movement of the blades. This uses a sun gear ( 16 ) mounted to the blade support and arranged to mesh with planet gears ( 17 ) that rotate about the blade pivot axes ( 14 ). In addition improvements are provided to blades ( 12, 33, 60 ) and blade mounting arrangements that balance compact folding of the blades ( 12, 33, 60 ) and good air moving effectiveness.
1. A combined ceiling fan and light fitting having folding fan blades comprising:
a motor having a shaft and casing which is mounted for rotation about a fan rotation axis;
mounting means for fixing an end of the shaft;
a blade support coupled to the casing of the motor for rotation therewith about said fan rotation axis;
a plurality of blades pivotally mounted on the blade support rotation about blade pivot axes between retracted and extended positions;
biasing means for biasing the blades into their retracted positions;
wherein the arrangement being such that, on operation of the motor, the casing rotates which causes rotation of the blades about said fan rotation axis and, due to centrifugal forces, about their respective blade pivot axes into their extended positions and, on de-activation of the motor, to return to their retracted positions by the action of the biasing means characterised in that the fitting includes synchronising means, said synchronising means includes a body which is mounted for limited rotation about said fan rotation axis relative to the blade support means and wherein the body carries first gear teeth which mesh with second teeth coupled to respective blades whereby the blades are constrained to rotate in synchronism about their respective blade pivot axes; and
wherein the body includes a slot or slots and the blade support includes one or more pegs which are received in the slots whereby said limited rotational movement is defined by contact between the peg or pegs and the ends of the slots.
2. A combined ceiling fan and light fitting according to claim 1 wherein in their retracted positions the blades lie when seen from above substantially within a peripheral boundary of the said blade support.
3. A combined ceiling fan and light fitting according to claim 1 wherein the fan blades are cambered along their lengths.
4. A combined ceiling fan and light fitting according to claim 1 wherein the blades are formed to have a variable angle of incidence to the horizontal when in their operative positions.
5. A combined ceiling fan and light fitting according to claim 1 wherein said blades have tips and said tips in their operative positions rotate in a plane closer to a ceiling from which the combined ceiling fan and light fitting is suspended than root ends of said blades.
6. A combined ceiling fan and light fitting according to claim 1 wherein the pivot axes of the blades are oriented other than parallel to the rotation axis of the electric motor.
7. A combined ceiling fan and light fitting according to claim 6 wherein the pivot axes are closer to the motor rotation axis immediately above the blades than immediately below the blades.
8. A combined ceiling fan and light fitting according to claim 1 wherein each of the blades each has a tip, root end, leading edge and trailing edge, the blade pivot axis being parallel to or canted relative to the fan rotation axis, and wherein, in cross-section through the blades in their folded positions at a radial plane which includes the fan rotation axis, the cross-sectional shape of each blade is defined by upper and lower edges wherein the upper edge includes a convex portion and the lower edge includes a concave portion; and,
wherein the tips of said blades are, in use, higher than root ends of said blades.
9. A combined ceiling fan and light fitting according to claim 8 wherein the pivot axes of the blades are oriented other than parallel to the rotation axis of the electric motor.
10. A combined ceiling fan and light fitting as claimed in claim 1 wherein the body is a ring.
11. A combined ceiling fan and light fitting as claimed in claim 10 wherein the ring and first gear teeth comprise a sun gear and the second teeth are on respective planet gears.
12. A combined ceiling fan and light fitting as claimed in claim 1 wherein the blade support is disc shaped and the body, first teeth, second teeth and biasing means are located beneath the blade support means.
13. A combined ceiling fan and light fitting as claimed in claim 1 wherein the biasing means includes springs which act between the blade support and said body.