Electric fan with detachable blades

An electric fan comprises a rotary hub comprising a hollow two-layer cylinder including a plurality of units each including: a gap between the layers, an axial first coupling edge abutted on an adjacent unit, an arcuate second coupling edge at its inner end joined with the first coupling edge, two internal ridges, and a rib interconnected the cylinder and a central sleeve; and a plurality of detachable blades comprising a blade section and a base including a raised member, a connecting edge in a joining portion of the blade section and the raised member, two side shoulders, and a forward, downward projection. Each base is inserted into the gap with the shoulders engaged with the ridges, the connecting edge engaged with the second coupling edge, and one side of the raised member engaged with the first coupling edge respectively. Also, each projection is threadedly secured to each rib.

FIELD OF THE INVENTION

The present invention relates to electric fans and more particularly to such an electric fan (e.g., floor fan) with a plurality of detachable fan blades.

BACKGROUND OF THE INVENTION

Conventionally, fan blades of an electric fan are integrally formed with a rotary hub. From the point of view of manufacture, it has the benefit of decreasing the number of fan components. However, it may hinder delivery because a large space is, occupied by the hub and the blades. The required space is even larger if the electric fan has a large size. Thus, it is desirable to provide an electric fan having detachable blades in order to overcome the above drawback of prior art.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an electric fan comprising a rotary hub comprising a central sleeve and a hollow two-layer cylinder including a plurality of blade mounts each including a gap between the layers, an axial first coupling edge abutted on an adjacent blade mount, an arcuate second coupling edge joined with the first coupling edge at an inner end thereof, two axial, spaced, internal ridges, and a rib interconnected the cylinder and the sleeve, the rib having a threaded aperture; and a plurality of detachable revolving blades comprising a base, a blade section supported on the base, a raised member on the base, a connecting edge in a joining portion of the blade section and the raised member, two side shoulders on the base, and a radially inward projection having a hole; wherein the base of each blade is inserted into the gap with the shoulders matingly engaged with the ridges, the connecting edge matingly engaged with the second coupling edge, and one side of the raised member matingly engaged with the first coupling edge respectively, and a fastener is adapted to drive through the hole into the threaded aperture for securing each blade to each blade mount. By utilizing the present invention, the storage space of the blades can be greatly reduced for ease of delivery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 1 to 6, there is shown a rotary hub10and a plurality of detachable revolving blades20of an electric fan (e.g., floor fan) in accordance with the invention. The hub10comprises a hollow cylinder11having its outer surface consisting of two proximate layers. Each cylinder11comprises a plurality of blade mounts each including a gap12between the layers, an axial first coupling edge13abutted on an adjacent blade mount, an arcuate second coupling edge14joined with the first coupling edge13at an inner end, two axial, spaced, internal ridges15, and a threaded aperture16in a rib interconnected the blade mount and a central sleeve.

The blade20comprises a blade section21, a raised member22on a base integrally formed with the blade section21, an edge23in a joining portion of the blade section21and the raised member22, two side shoulders24lower than the raised member22, the base of the blade20being inserted into the gap12with the shoulders24matingly engaged with the ridges15, the edge23matingly engaged with the second coupling edge14, and one side of the raised member22matingly engaged with the first coupling edge13respectively, and a hole25in a radially inward projection such that a fastener (e.g., screw) can be driven through the hole25into the threaded aperture16for fastening the blade20at the blade mount.