Hollow hanging rod of a hanger assembly for ceiling fan

Abstract

A hollow hanging rod includes a tubular section having an axial hole extending through a top open-end thereof, and a bowl-shaped section extending upwardly, curvedly, and expandedly from the top open-end of the tubular section and having a top open-end distal from the top open-end of the tubular section, a bottom open-end connected to the top open-end of the tubular section, and a surrounding wall connected between the top and bottom open-ends of the bowl-shaped section and defining an interior space with a width that gradually increases from the bottom to the top open-ends of the bowl-shaped section. The top open-end of the bowl-shaped section defines a single top opening having a width larger than that of the axial hole. The interior space opens at the single top opening. The tubular and bowl-shaped sections are made of metal, and are formed integrally as a one-piece body.

1 . A hollow hanging rod of a hanger assembly for a ceiling fan, comprising:
 a tubular section having a top open-end and an axial hole extending through said top open-end; and   a bowl-shaped section extending upwardly, curvedly, and expandedly from said top open-end of said tubular section and having a top open-end distal from said top open-end of said tubular section, a bottom open-end connected to said top open-end of said tubular section, and a surrounding wall connected between said top and bottom open-ends of said bowl-shaped section and defining an interior space with a width that gradually increases from said bottom open-end of said bowl-shaped section to said top open-end of said bowl-shaped section;   said top open-end of said bowl-shaped section defining a single top opening having a width larger than that of said axial hole;   said interior space opening at said single top opening; and   said tubular section and said bowl-shaped section being made of metal and being formed integrally as a one-piece body.   
   
   
       2 . The hanging rod of  claim 1 , wherein said surrounding wall has inner and outer surfaces, said bowl-shaped section further having a positioning slot provided in said surrounding wall, said positioning slot extending through said inner and outer surfaces of said surrounding wall and extending curvedly and downwardly from said top open-end of said bowl-shaped section toward said bottom open-end of said bowl-shaped section. 
   
   
       3 . The hanging rod of  claim 1 , wherein said surrounding wall has inner and outer surfaces, said bowl-shaped section further having a positioning groove provided in said surrounding wall, said positioning groove opening at said outer surface and extending curvedly and downwardly from said top open-end of said bowl-shaped section toward said bottom open-end of said bowl-shaped section. 
   
   
       4 . The hanging rod of  claim 1 , wherein said surrounding wall has a corrugated structure, and includes a plurality of alternating protrusions and indentations provided on said surrounding wall and extending from said top open-end of said bowl-shaped section to said bottom open-end of said bowl-shaped section. 
   
   
       5 . The hanging rod of  claim 1 , wherein said tubular section further has a bottom open-end, and a bottom engaging part tapering downwardly to said bottom open-end, said hanging rod further comprising an extension rod that has an upper engaging part fitted into said bottom engaging part and that extends downwardly and outwardly from said bottom open-end of said tubular section. 
   
   
       6 . The hanging rod of  claim 5 , wherein said tubular section further has a projection projecting from an inner surface of said bottom engaging part toward said axial hole and tapering upwardly from said bottom open-end of said tubular section, said extension rod further having an indentation indenting from an outer surface of said upper engaging part and receiving fittingly said projection. 
   
   
       7 . The hanging rod of  claim 6 , wherein said extension rod further has a lower fixing portion disposed below said upper engaging part and externally of said tubular section and adapted to be connected with the ceiling fan. 
   
   
       8 . A hollow hanging rod of a hanger assembly for a ceiling fan, comprising:
 a tubular section having a top open-end and an axial hole extending through said top open-end; and   a bowl-shaped section extending upwardly, curvedly, and expandedly from said top open-end of said tubular section and having a top open-end distal from said top open-end of said tubular section, a bottom open-end connected to said top open-end of said tubular section, and a surrounding wall connected between said top and bottom open-ends of said bowl-shaped section and defining an interior space with a width that gradually increases from said bottom open-end of said bowl-shaped section to said top open-end of said bowl-shaped section;   said top open-end of said bowl-shaped section defining a single top opening having a width larger than that of said axial hole;   said interior space opening at said single top opening;   said tubular section and said bowl-shaped section being made of metal and being formed integrally as a one-piece body; and   said hanging rod being made by a method which includes the steps of: (a) preparing a metal tube; and (b) partially expanding said metal tube to form said bowl-shaped section.   
   
   
       9 . The hanging rod of  claim 8 , wherein step (b) includes:
 inserting a middle part of said metal tube into a ball-shaped cavity of a mold with two opposite end portions thereof being disposed externally of the mold;   expanding said middle part by introducing a high-pressure hydraulic fluid into said middle part to form a ball-shaped middle part;   cutting said ball-shaped middle part into halves to obtain two said bowl-shaped sections, each of which is integral with one of said end portions.