Dual direction axial fan

Abstract

A dual direction axial fan is provided and includes a body having a retention assembly and being rotatable in first or second directions, a blade being retained by the retention assembly such that the airfoil section extends from the body with the blade assuming first, second or third orientations and a switching mechanism coupled to the retention assembly to urge the blade to assume the second or the third orientation when the body rotates in the first or the second direction, respectively.

1 . A dual direction axial fan, comprising:
 a body having a retention assembly and being rotatable in first or second directions;   a blade being retained by the retention assembly such that the airfoil section extends from the body with the blade assuming first, second or third orientations; and   a switching mechanism coupled to the retention assembly to urge the blade to assume the second or the third orientation when the body rotates in the first or the second direction, respectively.   
     
     
         2 . The dual direction axial fan according to  claim 1 , wherein the retention assembly, the blade and the switching mechanism are each correspondingly plural in number and arrayed about the body with uniform separation. 
     
     
         3 . The dual direction axial fan according to  claim 1 , wherein the switching mechanism comprises:
 a rack and pinion mechanism; and   a centrifugal switch mechanism operably coupled to the rack and pinion mechanism.   
     
     
         4 . The dual direction axial fan according to  claim 3 , wherein the body comprises:
 a hub having an annular sidewall and an end plate at a first end thereof, through which u-shaped pin holes are defined; and   a cover through which radial pin holes are defined, the cover being fittable to a second end of the sidewall such that the cover occupies and moves between first, second or third positions associated with the first, second and third orientations, respectively.   
     
     
         5 . The dual direction axial fan according to  claim 4 , wherein a radial through hole through which a shank of the blade extends is defined through the sidewall, the blade retention assembly comprising:
 a portion of the sidewall at which the radial through hole is defined; and   a first elastic element anchored on the hub and coupled to the shank of the blade.   
     
     
         6 . The dual direction axial fan according to  claim 5 , further comprising a sleeve, which is tightly fittable about the shank of the blade and which is engageable with the first elastic element. 
     
     
         7 . The dual direction axial fan according to  claim 5 , wherein the centrifugal switch mechanism comprises:
 an array of pin and nut combinations, each pin and nut combination being configured to respectively extend through a corresponding pair of a u-shaped pin hole and a radial pin hole; and   a second elastic element to bias each pin and nut combination toward a position whereby the cover is constrained in the second or the third position when the body rotates in the first or the second direction, respectively.   
     
     
         8 . The dual direction axial fan according to  claim 7 , wherein the rack and pinion mechanism comprises:
 a gear to which the shank of the blade is coupled; and   a rack of the cover to rotatably engage with the gear.   
     
     
         9 . A dual direction axial fan, comprising:
 a body having a blade retention assembly and being rotatable about a centerline thereof in first or second directions;   a blade having an airfoil section and a shank, the shank being retained in the body by the blade retention assembly such that the airfoil section extends from the body with the blade assuming first, second or third orientations; and   a switching mechanism coupled to the blade retention assembly to urge the blade to assume the second or the third orientation when the body rotates in the first or the second direction, respectively.   
     
     
         10 . The dual direction axial fan according to  claim 9 , wherein the blade retention assembly, the blade and the switching mechanism are each correspondingly plural in number and arrayed about the centerline of the body. 
     
     
         11 . The dual direction axial fan according to  claim 9 , wherein the switching mechanism comprises:
 a rack and pinion mechanism; and   a centrifugal switch mechanism operably coupled to the rack and pinion mechanism.   
     
     
         12 . The dual direction axial fan according to  claim 11 , wherein the body comprises:
 a hub having an annular sidewall and an end plate at a first end thereof, through which u-shaped pin holes are defined; and   a cover through which radial pin holes are defined, the cover being fittable to a second end of the sidewall such that the cover occupies and moves between first, second or third positions associated with the first, second and third orientations, respectively.   
     
     
         13 . The dual direction axial fan according to  claim 12 , wherein a radial through hole through which the shank of the blade extends is defined through the sidewall. 
     
     
         14 . The dual direction axial fan according to  claim 13 , wherein the blade retention assembly comprises:
 a portion of the sidewall at which the radial through hole is defined; and   a first elastic element anchored on the hub and coupled to the shank of the blade.   
     
     
         15 . The dual direction axial fan according to  claim 14 , further comprising a sleeve, which is tightly fittable about the shank of the blade and which is engageable with the first elastic element. 
     
     
         16 . The dual direction axial fan according to  claim 12 , wherein the u-shaped pin holes are defined about an axial aperture through the end plate. 
     
     
         17 . The dual direction axial fan according to  claim 12 , wherein the centrifugal switch mechanism comprises:
 an array of pin and nut combinations, each pin and nut combination being configured to respectively extend through a corresponding pair of a u-shaped pin hole and a radial pin hole; and   a second elastic element to bias each pin and nut combination toward a position whereby the cover is constrained in the second or the third position when the body rotates in the first or the second direction, respectively.   
     
     
         18 . The dual direction axial fan according to  claim 17 , wherein the rack and pinion mechanism comprises:
 a gear to which the shank of the blade is coupled; and   a rack of the cover to rotatably engage with the gear.   
     
     
         19 . The dual direction axial fan according to  claim 18 , wherein the gear comprises:
 a ring portion connected to the shank of the blade; and   teeth extending from the ring portion to rotatably engage with the rack of the cover.   
     
     
         20 . A dual direction axial fan, comprising:
 a hub, which is rotatable about a centerline thereof, having an annular sidewall and an endplate at a first end of the annular sidewall through which a u-shape hole is defined;   a cover, through which a radial hole is defined, and which is fittable to a second end of the sidewall such that the cover occupies and moves between first, second or third positions;   a blade having a shank to extend through a radial hole defined in the sidewall, the blade being configured to assume first, second or third orientations;   a sleeve, which is tightly fittable about the shank of the blade;   a first elastic element anchored on the hub and engageable with the sleeve;   a pin and nut combination to extend through a corresponding pair of the u-shaped hole and the radial hole; and   a second elastic element to bias the pin and nut combination toward a position whereby the cover is constrained in the second or the third position when the hub rotates in the first or the second direction, respectively.