Wooden fan blade

A wooden fan blade includes an elongated blade body and a rib strip fitted into the elongated blade body. The blade body is made of a wooden plate having wooden fibers extended substantially in parallel to a longitudinal axis of the blade body. The blade body has an elongated groove transversely disposed at one side thereof across the extending direction of the wooden fibers of the wooden plate. The rib strip is fitted into the elongated groove and has a plurality of raised portions respectively forced into engagement with the blade body in the elongated groove.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to fan blades and, more particularly, to a deformation-protective wooden fan blade.

2. Description of the Related Art

Regular fan blades for ceiling fans may be molded from hard plastics, or made of metal or wood. Wooden fan blades are most invited on the market for the advantage of the friendly quality of their wooden fiber pattern. In order to prevent curving of the blade body in longitudinal direction, a wooden fan blade has the wooden fibers extended substantially in parallel to the longitudinal axis of the blade body. However, this arrangement cannot prohibit the blade body from curving in transverse direction. Further, a wooden fan blade may break or split between fiber bundles due to a severe temperature or moisture change, causing the blade body to fall from the housing of the ceiling fan during rotary motion of the ceiling fan.

SUMMARY OF THE INVENTION

It is the primary objective of the present invention to provide a deformation-protective wooden fan blade, which has means to protect the fan blade body from curving and splitting.

To achieve this objective of the present invention, the wooden fan blade comprises a blade body and a rib strip fitted into the blade body. The blade body is made of a narrow, elongated flat wooden plate having wooden fibers extended substantially in parallel to a longitudinal axis of the blade body. The blade body has an elongated groove transversely disposed at one side thereof across the extending direction of the wooden fibers of the wooden plate. The rib strip is fitted into the elongated groove and has a plurality of raised portions respectively forced into engagement with the blade body in the elongated groove. The rib strip protects the blade body from deformation. The raised portions of the rib strip prevent breaking of the blade body between fiber bundles.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1˜4, a wooden fan blade in accordance with the present invention is shown comprised of a blade body10and three rib strips20. The blade body10is a narrow, elongated flat member made of wood and shaped like a tree leaf. The fibers of the wooden material of the blade body10extend substantially in parallel to the longitudinal axis (major axis) of the blade body10. The blade body10has a longitudinal reinforcing midrib11protruded from one side and shaped like the midrib of a real tree leaf, and three elongated grooves12transversely disposed at the other side across the extending direction of the fibers of the wooden material of the blade body10.

The rib strips20are made of hard metal and shaped like a U-shaped channel bar, each having two sets of equally spaced raised portions21respectively arranged in line at each of the two opposite long sides along the longitudinal axis of the rib strip. The length and width of the rib strips20are approximately equal to the length and depth of the elongated grooves12.

The rib strips20are respectively hammered into the elongated grooves12, forcing the raised portions21of the rib strips20into engagement with the two opposite longitudinal sidewalls of each of the elongated grooves12. Therefore, the rib strips20are firmly secured to the blade body10(seeFIG. 4).

Because the rib strips20are respectively fastened to the elongated grooves12of the blade body10, they protect the blade body10against bending in transverse direction (the minor axis direction). Further, the raised portions21of the rib strips20impart a retaining force to the fibers of the wooden material of the blade body10in transverse direction, preventing breaking of the blade body10between the fibers bundles.

Therefore, a wooden fan blade made according to the present invention is durable in use, not easy to deform or split.

The invention is not limited to the use of the aforesaid rib strips. Any arrangement of rib strips that protects the blade body from curving inwards in the transverse direction (minor axis direction) and impart a transverse retaining force to the fibers of the wooden material of the blade body can be employed to the present invention.FIG. 5shows an alternate form of the present invention (it is a cross-sectional view taken along one rib strip). This alternate form is substantially similar to the aforesaid embodiment with the exception that the raised portions31of the rib strips30are disposed at the bottom side corresponding to the bottom walls of the elongated grooves32. When press-fitted the rib strips30into the elongated grooves32, the raised portions31are respectively driven into the bottom walls of the elongated grooves32.