Umbrella rib assembly

Abstract

An umbrella rib assembly for coupling a ventilating canopy to a main support shaft includes a plurality of first ribs, a plurality of second ribs and a plurality of fastening units. First and second upper surfaces of the first and second ribs are adapted for attachment of central and surrounding canopy patches thereto, respectively. The first and second ribs have first and second coupling segments coupled with each other such that the first and second upper surfaces are offset from each other so as to define an annular space between the central and peripheral canopy patches for ventilation purposes. Each fastening unit is disposed to fasten the second coupling segment to the first coupling segment.

1 . A rib assembly for coupling a ventilating canopy to a main support shaft of an umbrella, the canopy including a central canopy patch and a peripheral canopy patch which surrounds the central canopy patch about an axis defined by the main support shaft, said rib assembly comprising:
 a plurality of first ribs made from a rigid material, each of said first ribs including a connected end which is adapted to be pivoted to the main support shaft, a first coupling segment opposite to said connected end, and a first middle segment which is interposed between said connected end and said first coupling segment, each of said first ribs having a first upper surface which extends from said first coupling segment to said first middle segment, said first upper surface of said first middle segment being adapted for attachment of the central canopy patch thereto;   a plurality of second ribs made from a rigid material, each of said second ribs having a second upper surface adapted for attachment of the peripheral canopy patch thereto, each of said second ribs including a second coupling segment which is coupled with said first coupling segment of a respective one of said first ribs, and an extending segment which extends from said second coupling segment in a radial direction relative to the axis and away from said first middle segment such that said second upper surface is offset from said first upper surface in a transverse direction relative to the radial direction, thereby defining an annular space between the central and peripheral canopy patches; and   a plurality of fastening units, each disposed to fasten said second coupling segment of a respective one of said second ribs to said first coupling segment of the respective one of said first ribs.   
   
   
       2 . The rib assembly according to  claim 1 , wherein said first and second coupling segments respectively have first and second lateral surfaces which extend in the transverse direction and which are connected respectively to said first and second upper surfaces, each of said fastening units including a connecting plate which extends in the transverse direction and which confronts said first and second lateral surfaces, and a plurality of fasteners which fasten said connecting plate to said first and second lateral surfaces. 
   
   
       3 . The rib assembly according to  claim 1 , wherein each of said fastening units includes a tubular coupler which defines a channel therein, and which has a partition wall that extends in the radial direction to divide said channel into first and second compartments for passage of said first and second coupling segments, respectively, such that said first and second coupling segments are spaced apart from each other in the transverse direction, and a plurality of fasteners which fasten said tubular coupler to said first and second coupling segments. 
   
   
       4 . The rib assembly according to  claim 3 , wherein said tubular coupler further has a plurality of spacers which extend from said partition wall in the transverse direction into said first and second compartments, respectively, to permit passage of air between said first coupling segment and said partition wall, and between said second coupling segment and said partition wall.