Patent Publication Number: US-3877153-A

Title: Hair drying hood

Description:
United States Patent 1 1 [111 3,877,153 Keimpema Apr. 15, 1975 HAIR DRYING HOOD 3/1953 Schwaneke 34/100 Inventor: Keimpe Klaas Keimpema,  
 Zoetermeer, Netherlands U.S. Philips Corporation, New York, NY.  
 Filed: Feb. 26, 1974 Appl. No.: 445,993  
 Assignee:  
 Foreign Application Priority Data Mar. 21, 1973 Netherlands 7303929 U.S. Cl 314/99; 219/370 Int. Cl A45d 20/24 Field of Search 34/96-101, 34/3, 90, 91, DIG. 7, 83; 219/366, 369, 370, 371, 372  
  References Cited UNITED STATES PATENTS 7/1932 Kunian et a1. 34/99 FOREIGN PATENTS OR APPLICATIONS 915,436 l/1963 United Kingdom 34/99 Primary Examiner--l(enneth W, Sprague Assistant Examiner-James C. Yeung Attorney, Agent, or FirmFrank R. Trifari [57] ABSTRACT A hair drying hood comprising&#39;a radial fan coupled to an electric motor supported by an arm, with a heating element situated around the fan. The connection points of the heating element to a current source are disposed at an angle a of rotation relative to the location of the connection points, such that air flow impeded by the arm will coincide with the connection points which require less air flow than the heating element to avoid overheating.  
 3 Claims, 2 Drawing Figures HAIR DRYING noon BACKGROUND OF THE INVENTION The invention relates to a hair drying hood comprising a radial fan which is coupled to an electric motor with a heating element diposed around the fan, and a motor supported by a radially extending arm. A drawback of this arrangement is that the so-called shadow effect of the arm results in anon-ventilated spot at the circumference of the fan wheel, so that the heating element is likely to be overheated at this location. This effect can be mitigated by increasing the distance between the motor and the fan wheel, but this requires additional provisions as regards the construction for supporting the fan wheel, while moreover it leads to an increase in the dimensions of the hood.  
 SUMMARY OF THE INVENTION It is an object of the invention to provide a simple solution, which is characterized in that the connection points of the heating element are situated at the nonventilated spot at the circumference of the fan wheel which is caused by the so-called shadow-effect of the arm. The invention will be described by way of example with reference to drawings of a preferred embodiment.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the hair drying hood, showing the hood wall in cross-section.  
  FIG. 2 is a cross-sectional view taken along the line l-I in FIG. 1.  
 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As is shown in the Figures the hood 1 accommodates an electric motor 2, a fan wheel 4 with vanes 5 being disposed on the shaft 3. Air which is drawn in through the apertures 6, enters the fan wheel in a substantially axial direction and is blown out at the circumference in a substantially radial direction. Subsequently, while passing the heating element 7 the air is being heated and finally reaches the drying space 9 via the guard 8. The flow path of the air is indicated by the arrows P in FIG. 1.  
  The motor 2 is supported by a radially extending arm 10 which is attached to the hood wall. Especially in the case of asynchronous motors with an asymmetrical construction, the arm 10 will entirely or partly form part of the motor 2. Said arm 10 partly impedes the air stream, so that no air or a limited amount of air is fed to the part of the fan wheel whose vanes 5 pass the arm. This effect becomes increasingly marked as the distance between the arm and the fan wheel decreases. Since the air which has entered the fan wheel emerges at the circumference after the fan wheel has rotated through an angle a, this means that viewed in the direction of rotation at the location of an angle 0: beyond the arm 10, little or no air is expelled by the fan wheel. At  
 this location where there is no air circulation there is a danger that the heating element 7 will become overheated.  
  The heating element 7 which surrounds the fan wheel is provided with connection points 11 and 12 and may, for example, be supported at various points by brackets which are attached to the hood wall but which for simplicity are not shown. Since no part of the element is situated between the connection points 11 and 12, the air which passes between said points is not heated. Moreover, the temperature of the element at the location of the connection points 11 and 12 is lower than at the other points of the elements, because the electric leads to the connection points will carry off heat by conduction. As a result of this, a local cold air stream is produced in the drying space. However, arranging the heating element 7 and the motor arm 10 so that the small space between the connection points 11 and 12 is disposed at one radius which viewed in the direction of rotation is located an angle a after the arm 10, ensures that at the very location of the connection points 11 and 12 little or no air is expelled. Thus, both the danger of local overheating of the heating element and of a local stream of cold air in the drying space is avoided. Moreover, the distance between the arm 10 and the fan wheel 4 may be very small so that a compact construction of the hair drying hood is possible.  
 What is claimed is:  
  1. In a hair drying hood operable with a source of electric current and including a hood formed generally a cylindrical wall with air inlet and outlet ends and defining a space with a central area, a radial-flow fan, an electric motor coupled to said fan for supporting and rotating same, and an arm supporting said motor in said central area, the arm extending generally radially outward and secured to said wall, wherein air from said air inlet that enters the fan generally axially at any circumferential entering location is expelled by said fan generally radially at a circumferential location 0: degrees of rotation in the direction of fan rotation, relative to said entering location, and wherein said arm is situated intermediate said air inlet end and said fan and impedes airflow therebetween thus creating an area of poor air circulation at a location at 11 degrees in the direction of fan rotation relative to the location of said arm, the improvement in combination therewith of an electric heating element formed as a partial circular arc and situated radially outward of and adjacent said fan, said heating element having two ends connectible to said current source, said ends being situated at said area of poor air circulation.  
  2. Apparatus according to claim 1 wherein said radial fan comprises a wheel having flat blades which extend axially and radially outward.  
  3. Apparatus according to claim 1 wherein said air inlet and outlet ends have a plurality of apertures for passage of air therethrough.