Quiet hair dryer

Abstract

An improved quiet (low noise) hair dryer, which includes a handle for holding the same and supporting its blower assembly having a motor driven centrifugal fan assembly, achieves a significant reduction of noise by employing balanced volume inlets above and below the fan rotor, a special fan rotor configuration having blades with airfoil shapes and a curved trailing edges and diffuser ring in its outlet that employs the Coanda effect in the air exiting the dryer. The dryer can also include a resistive heating element to increase the temperature of the exiting air and, includes the necessary switches and cords for operation of its heating element and electric motor.

Having described the invention, I/we claim: 
     
         1 . A quiet handheld hair dryer comprising:
 handle means for holding the dryer;   a hollow blower assembly with top and bottom inlet bezel means mounted on said handle, said top and bottom bezel means each having equal open diameters for balanced air inflow into said blower assembly and said blower assembly having an internal a torus shaped chamber for housing a centrifugal fan;   a squirrel cage fan rotor having a plurality of blades mounted in such torus shaped chamber, each of said blades of said fan rotor having an air foil configuration;   an electric motor means mounted inside of said squirrel cage fan rotor with its armature connected in driving relationship with said fan rotor operable to rotate it, said electric motor means having its base supported through one of said bezel means so that said fan rotor is adjacent to both of said inlet bezel means; and   tubular throat means connected to the outlet of said blower assembly having an outlet for the air flow generated by said blower assembly; and   control means connected said motor means and having means to connect to a source of electricity and switch means operable to control electricity to said electrical motor means.   
     
     
         2 . The novel hair dryer defined in  claim 1  wherein a diffusing ring is placed proximate to the outlet of the tubular throat means to reduce the turbulence in the exiting air stream when said dryer is operated. 
     
     
         3 . The novel hair dryer defined in  claim 1  wherein the throat means contains internal electrical resistive heating coils and the control means is operable to control electricity to said resistive heating coils. 
     
     
         4 . A quiet handheld hair dryer comprising:
 handle means for holding the novel dryer;   a hollow blower assembly with top inlet bezel means and bottom inlet bezel means mounted on said handle, said bezel means each having equal open diameters for balanced air inflow into said blower assembly and said blower assembly having an internal a torus shaped chamber designed for housing a centrifugal fan;   a squirrel cage fan rotor sized to fit into said blower assembly having a plurality of blades and mounted in such torus shaped chamber, each of said blades of said fan rotor having an air foil configuration;   electric motor means mounted inside of said squirrel cage rotor with its armature connected in driving relationship with said fan rotor operable to rotate it, said electric motor means having its base supported through one of said bezel means so that said fan rotor is adjacent to both of said inlet bezel means;   tubular throat means connected to the outlet of said blower assembly and having an outlet for the air flow generated by said blower assembly passing there through; and   control means connected to said motor means having means to connect it to a source of electricity and switch means operable to control the flow of electricity to said electrical motor means.   
     
     
         5 . The novel hair dryer defined in  claim 4  wherein the fan rotor is formed with a spindle having radially extending spokes connected to an assembly ring on which the individual blades are mounted in equal spacing. 
     
     
         6 . The novel hair dryer defined in  claim 5  wherein the trailing edges of the individual blades on the fan rotor have a semicircular profile operable to decrease the aerodynamic noise as each blade as it passes the cut off location. 
     
     
         7 . The novel hair dryer defined in  claim 4  wherein the tubular throat means has an increasing internal diameter from its connection to the blower assembly to its outlet operable to decreases the pressure of the air flow existing from said blower assembly and to increase its velocity. 
     
     
         8 . The novel hair dryer defined in  claim 7  wherein the outlet of the throat means connects to a diffuser tube means, said tube means having a diffuser ring mounted in its outlet operable to increase the velocity of air flow flowing through such aperture. 
     
     
         9 . The novel hair dryer defined in  claim 7  wherein the diffuser tube means has a constant internal diameter. 
     
     
         10 . The novel hair dryer defined in  claim 8  wherein the cross sectional diameter of the diffuser ring from is 4 to 6 mm. 
     
     
         11 . The novel hair dryer defined in  claim 6  wherein the throat has resistive heating means disposed therein operable to heat the air flow passing through said throat means. 
     
     
         12 . The novel hair dryer defined in  claim 11  wherein the control means has connections to the resistive heating means and is operable to control the electric current supplied to said resistive heating means.