Handheld hair care appliance with adjustable diameter barrel providing heated airflow

#The present invention relates to electrically powered hand held hair curling appliances of the type comprising a handle by means of which the appliance is held; a barrel extending from the handle on which the hair to be curled is wound externally, the barrel being hollow to allow fluid flow along the barrel, the barrel being provided with apertures to allow the fluid to flow outwardly to the hair, and the barrel being of adjustable diameter between a fully expanded and a fully contracted state to allow curls of different diameter to be formed.

#DE-A-25 28 822 in the name Hubner and DE-A-25 29 026 in the same name (the latter being an application for a patent of addition to the former) both describe hair curling appliances. Hubner describes a hair curling appliance which uses steam as a fluid. The barrel consists of a hollow perforated cylinder which is of fixed diameter, on the outside of which are pivotally mounted a number of perforated semicircular segments. The segments may be pivotally moved together outwardly to increase the diameter of the barrel or inwardly to decrease the diameter of the barrel.

#The Hubner hair curler suffers from a number of disadvantages. Firstly, the Hubner barrel has a large diameter even when fully contracted. This large diameter arises from the construction, in particular because the barrel comprises segments fixed externally to a cylinder. The minimum diameter is stated to be 20 mm, which is at the upper end of the range of desirable curl diameters. Secondly, the Hubner appliance is intended to apply a low volume, low pressure supply of steam to the hair. It would be unsuitable for use in applying a substantial flow of dry warm air to the hair for the purpose of drying and styling, in particular because in the Hubner appliance the fluid must flow along a circuitous path from the interior of the cylinder out through one set of apertures into the area between the cylinder and the segments, and then out through another set of apertures to the hair. The two sets of apertures are generally not aligned with another. Finally, the appliance proposed by Hubner would suffer from condensation problems with drops of water falling from the appliance onto the hair.

#FIG. 1 is a side elevation of a warm air brush including a barrel of adjustable diameter in accordance with the invention shown in the expanded state;

#FIG. 2 is a view similar to FIG. 1, but showing the barrel in cross section;

#FIG. 3 is an exploded perspective view of the barrel on a larger scale, showing the principal components;

#Referring now to FIGS. 1 to 7 of the drawings, the warm air brush comprises a gripping handle 1, a barrel 2 which is used to brush the hair, and a heater blower (shown in phantom) located in the gripping handle 1 for heating a which is then directed along the barrel 1 and emerges through apertures described below to warm the hair being brushed.

#The barrel 2 consists of six elongate barrel elements 3 arranged in mutually parallel radial relationship to form a generally cylindrical barrel. Each barrel element 3 consists of a base 3a, a row of projecting brush teeth 3b, a lateral projection 3c at one side of the base for underlying the base 3a of the adjacent element, a row of apertures 3d in the base 3a and a row of indentations 3e in the lateral projection 3c. Each barrel element 3 is integrally formed of plastic material but includes a metal stiffening rod 3f. FIG. 5b shows the barrel 2 in the fully contracted state with the bases 3a abutting one another FIG. 5a shows the barrel 2 in the fully expanded state with gaps between the bases 3a, these gaps being closed by the lateral projections 3c. Closure of the gaps ensures that the barrel 2 is substantially closed so that the warm air flowing down the barrel escapes only through the apertures 3d. The external diameter of the barrel 2 is 14 mm in the fully contracted state and 21 mm in the fully expanded state.

#As best seen in FIGS. 4a and 4b, the apertures 3d are always unobstructed, allowing a substantial volume of warm dry air to be delivered directly from the interior of the barrel 2 to the hair, without any risk of back pressure or overheating of the heater blower. When the barrel 2 is in the fully expanded state as shown in FIG. 4a, air emerges through the apertures 3d and also through the indentations 3e. When the barrel 2 is in the fully contracted state as shown in FIG. 4b, the indentations 3e move into register with the apertures 3d, so that the apertures remain unobstructed.