Radial blower for a leaf and waste collection/removal apparatus with operating noise suppression means

Abstract

The radial blower for a leaf and waste vacuum apparatus, a leaf and waste blower apparatus or a leaf and waste loading apparatus has a Helmholz resonator ( 14 ) for damping or attenuating sound generated by the blower. The Helmholtz blower ( 14 ) is connected to the sound conducting flow duct ( 12 ) of the blower ( 10 ) with a connector pipe ( 13 ). The sound resonance eigenfrequencies are adjusted by changing the cross-sectional area (A) of the connector pipe ( 13 ), the length (l) of the connector pipe ( 13 ) and/or the volume (V) of the Helmholz resonator.

We claim:  
     
         1 . A radial blower for a leaf and waste vacuum apparatus, a leaf and waste blower apparatus or a leaf and waste loading apparatus, said radial blower comprising a sound conducting flow duct ( 12 ) and a sound damping or attenuating device; 
 wherein said sound damping or attenuating device comprises a Helmholtz resonator ( 14 ).    
     
     
         2 . The radial blower as defined in  claim 1 , wherein said Helmholtz resonator ( 14 ) is mounted on the sound conducting flow duct ( 12 ) by at least one pipe connector ( 13 ), said at least one pipe connector connecting the Helmholz resonator ( 14 ) with the sound conducting flow duct ( 12 ).  
     
     
         3 . The radial blower as defined in  claim 1 , wherein said Helmholtz resonator ( 14 ) has sound resonance eigenfrequencies and means for adjusting said sound resonance eigenfrequencies.  
     
     
         4 . The radial blower as defined in  claim 2 , wherein said at least one pipe connector ( 13 ) is exchangeable or replaceable by at least one other pipe connector having geometric parameters or dimensions that are different from those of said at least one pipe connector ( 13 ).  
     
     
         5 . The radial blower as defined in  claim 2 , wherein said at least one pipe connector ( 13 ) has a transverse cross-sectional area (A) and a length (l) and means for adjusting at least one of said cross-sectional area (A) and said length (l).  
     
     
         6 . The radial blower as defined in  claim 5 , wherein said at least one pipe connector ( 13 ) is a telescoping connector pipe, whereby said length (l) is adjustable.  
     
     
         7 . The radial blower as defined in  claim 5 , further comprising an insert ( 19 ) for said at least one pipe connector ( 13 ) for adjusting said cross-sectional area (A).  
     
     
         8 . The radial blower as defined in  claim 1 , wherein said Helmholtz resonator ( 14 ) has a volume (V) and said volume (V) is adjustable.  
     
     
         9 . The radial blower as defined in  claim 8 , wherein said Helmholtz resonator ( 14 ) has a movable wall ( 17 ) for adjusting said volume (V).