Blower duct

Abstract

A portable-blower duct has a bendable portion whose inner peripheral surface is a cylindrical surface without any protrusions or recesses in a normal state or in an expanded state, that is, unless it is greatly curved. With this construction, no turbulence is generated in air passing through a tube, thereby making it possible to suppress pressure loss. Thus, the flow velocity of air guided through the duct is not reduced, thereby suppressing a deterioration in air blowing efficiency. Even when the tube is curved, the outer side of the curved portion is expanded, and the corresponding portion of the inner peripheral surface remains a smooth surface, thus making it possible to minimize the air pressure loss.

1 . A blower comprising:
 a blower main body having an air-sending port and being arranged to supply air to the air-sending port;   a duct comprising:
 a bendable portion including a flexible tube having a smooth inner peripheral surface at least in a non-contracted state, 
 a plurality of protruding portions formed along a circumferential direction of the tube and arranged at predetermined intervals in an axial direction of the tube, and 
 an elbow that connects the air-sending port with the bendable portions 
   wherein an inner diameter of the elbow is substantially the same as an inner diameter of the air-sending port.   
   
   
       2 . A blower according to  claim 1 , wherein:
 the tube is a cylindrical member made of a synthetic resin; and   the protruding portions are formed integrally with the tube so that the protruding portions are continuous with an outer peripheral surface of the tube.   
   
   
       3 . A blower according to  claim 1 , wherein the protruding portions are annular. 
   
   
       4 . A blower according to  claim 1 , wherein the plurality of protruding portions are connected to one another as a spiral configuration on an outer peripheral surface of the tube, with adjacent portions thereof being arranged at predetermined intervals. 
   
   
       5 . The blower according to  claim 1 , wherein the blower main body is arranged to supply a predetermined amount of air to the air-sending port. 
   
   
       6 . The blower according to  claim 1 , wherein the elbow is curved in a circular arc shape.