US 4,596,921 A · Low noise hand-held hairdryer

Abstract

A hand-held hair dryer with a high level of sound and vibration suppression. The hair dryer includes sound absorbing material attached to the inner surface of the hair dryer housing and having a selected density to provide maximum sound absorption in a relatively thin layer of material. A motor with integral fan is mounted on the hair dryer handle by an elastomeric vibration isolator so as to be isolated from the dryer housing. The fan blade noise, in part absorbed by the sound absorbing material on the inner surface of the hair dryer housing, is further grossly suppressed by special sound absorbing structures located at the extreme inlet and outlet of the housing, such as a structure functioning as a Helmholtz resonator, with that structure itself being vibration isolated from the hair dryer housing. Preferably an aerodynamically designed heater is used downstream of the fan to minimize the vortex noise. Also, vibration isolation between the handle and the main housing assembly provides good low frequency vibration absorption, particularly with the motor being supported through the handle rather than through the main housing itself. Various embodiments and other features of the invention are also disclosed.

Claims36

Dependent claims

A hand-held hairdryer comprising

a substantially rigid housing having an inlet and an outlet for airflow therethrough;
a substantially rigid handle means, said housing being coupled to said handle means;
a motor within said housing, said motor being mounted on vibration isolation means within said handle means, said vibration isolation means being an elastic means for absorbing vibrational energy between said motor and said handle means;
a fan mounted on said motor and oriented to encourage airflow through said housing from said inlet to said outlet;
a nonrotating shroud within said housing and encircling said fan
an electric heater mounted in said housing downstream of said fan;
and
a sound absorbing material lining said housing between said inlet and said outlet thereof, said sound absorbing material being shaped so as to provide a substantially smooth duct free of rapid changes in duct cross-section area along its length for airflow between said inlet and said outlet.

5 more elements

A hand-held hairdryer comprising a substantially rigid housing having a substantially smooth duct therein, including an inlet and an outlet for airflow therethrough;

a substantially rigid handle means, said housing being coupled to said handle means;
a motor mounted in said housing;
a fan mounted on said motor and oriented to encourage air flow through said housing from said inlet to said outlet;
an electric heater mounted in said housing downstream of said fan;
and
at least one Helmholtz oscillator mounted within said housing and forming part of said duct, said Helmholtz oscillator being a means for absorbing pressure disturbances at and near the resonant frequency thereof;
wherein said motor and fan operate at a predetermined speed, whereby said fan generates pressure disturbances having a primary component at a predetermined frequency equal to the fan blade passing rate, and wherein said at least one Helmholtz oscillator is tuned to have a resonant frequency substantially equal to said predetermined frequency.

4 more elements

Dependencies are inferred from the claim text.

Low noise hand-held hairdryer

Life of this patent

Low noise hand-held hairdryer

Life of this patent

Abstract

Claims36