Electrically powered hand held hair curling appliance

Abstract: The invention relates to electrically powered hand held hair curling appliances of the type comprising a barrel (2) for delivering warm air to the hair, the barrel (2) being of adjustable diameter to allow curls of different diameter to be formed. The barrel (2) consists of a number of barrel elements (3) which can be moved radially outwardly or radially inwardly to expand or contract the barrel, the elements (3) overlapping one another when contracted but always allowing unobstructed air flow from the interior of the barrel (2) out through apertures (3d) to the hair.

Description: 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 29 016 in the same name (the latter being an application for a patent of addition to the former) both describe hair curling appliances of the type described. 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 semi-circular 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 DE-A-2 529 026 hair curler suffers from a number of disadvantages. Firstly, the DE-A-2 529 026 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 and of the range of desirable curl diameters. Secondly, the DE-A-2 529 026 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 one another. Finally the appliance proposed by DE-A-2 529 026 would suffer from condensation problems with drops of water falling from the appliance onto the hair. US-A-3,921,648 also describes a hair curling appliance of the type described. The appliance is a steam curling iron. The barrel consists of a central hollow perforated cylinder of fixed diameter on the outside of which is mounted a perforated expansible mandrel of resilient stainless steel. The US-A-3 921 648 hair curling appliance suffers from the same disadvantages as the DE-A-2 529 026 appliance; namely a large diameter when fully contracted arising from the two-layer structure, unsuitability for high volume flow of warm dry air arising from a circuitous path through two sets of apertures which are not in register, and condensation leading to drops of water falling on the hair. According to the invention there is provided a hair curling appliance of the type described in which the barrel is formed by a number of elongate barrel elements arranged in mutually parallel radial relationship to form a generally axially symmetric barrel, said elongate barrel elements defining the inner and outer diameters of said barrel and being movable radially inwardly together and radially outwardly together so as to contract and expand the inner and outer diameters of the barrel, the barrel elements mutually combining to form a substantially closed barrel when in the fully expanded state and a substantially closed barrel with overlapping barrel elements in the contracted state, and the barrel elements being provided with apertures which allow fluid to flow from the interior of the barrel directly out to the hair when the barrel is in the fully expanded, fully contracted or any intermediate state. Thus there is provided an improved curling appliance of the type described which has a substantially smaller diameter than the prior art devices. There is also provided an improved hair curling appliance of the type described which can deliver a substantial flow or warm dry air to the hair. The hair curling appliance according to the invention has a number of advantages. Firstly, the structure allows a barrel of small diameter to be constructed. Secondly, air flow idrectly form the interior of the barrel to the hair, allowing a large volume of air to be applied to the hair. There now follows a description of preferred embodiments of the invention, by way of example, with reference being made to the accompanying drawings, in which: Figure 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; Figure 2 is a view similar to Figure 1, but showing the barrel in cross section; Figure 3 is an exploded perspective view of the barrel on a larger scale, showing the principal components; Figure 4 shows on a larger scale one of the components shown in Figure 3, namely a barrel element; Figure 4a & 4b show two adjacent barrel elements with the barrel in the fully expanded and the fully contracted state respectively; Figures 5a & 5b are sectional views on A-A of Figure 2 and show the barrel in the expanded and contracted state thereof respectively; Figure 6 & 7 are views similar to Figure 2, but on a large scale, showing the adjustment mechanism for the barrel, Figure 6 showing the outer end of the barrel and Figure 7 showing the inner end; Figure 8 is a view similar to Figure 3, but showing a modified construction of warm air brush; and Figure 9 is a sectional side elevation of the barrel and adjustment mechanism of the modified construction. Referring now to Figures 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 (not shown) located in the gripping handle 1 for heating air which is then directed along the barrel 2 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. Figure 5b shows the barrel 2 in the fully contracted state with the bases 3a abutting one another. Figure 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 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 Figures 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 backpressure or overheating of the heater blower. When the barrel 2 is in the fully expanded state as shown in Figure 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 Figure 4b, the indentations 3e move into register with the apertures 3d, so that the apertures remain unobstracted. The user expands or contracts the barrel 2 by means of the adjustment knob 4 located at the tip of the barrel. The user grips the knob 4, depressing the knob axially along the barrel 2 towards the handle 1 against spring biassing so as to disengage the knob 4 from a locking mechanism, the user then rotates the knob 4 clockwise to expand the barrel 2 or anti-clockwise to contract the barrel 2, and then releases the knob 4 so that the latter moves axially back along the barrel 2 under the influence of the spring biassing and re-engages the locking mechanism to prevent further rotation. The locking mechanism will now be described. A fixed central shaft 5 extends from the handle 1. A washer 6 and cap 7 are provided at the outer end of the fixed central shaft 5. A flanged collar 8 is fixedly mounted at the end of the shaft 5 just inwardly of the cap 7 and washer 6, and has gear-teeth 8a on the outer circumferential surface of the flange. The adjustment knob 4 has teeth 4a on the inner circumferential surface which in the normal position thereof as shown in Figure 6 engage with the teeth 8a on the flanged collar 8, thereby preventing rotation of the adjustment knob 4. The adjustment knob 4 is held in the normal position by a coiled compression spring 9 which biasses the adjustment knob 4 towards the outer end of the shaft 5 into abutment with the washer 6. The adjustment mechanism will now be described. When the adjustment knob 4 is depressed against the action of the coiled compression spring 9, the inwardly projecting teeth 4a of the adjustment knob 4 move out of meshing engagement with the externally projecting teeth 8a on the flanged collar 8, allowing the adjustment knob 4 to be rotated. The subsequent rotation of the adjustment knob 4 causes corresponding rotation of nut 10, the adjustment knob 4 and nut 10 being held together by meshing gears 4a, 10a. The nut 10 is threaded on external screw threading 11a on the shank of front cam 11 which is slidably mounted on the central shaft 5. Double helix threading is used for extra stability. The nut 10 is held in a fixed axial position between the front cam housing 18 and the flanged collar 8. As a result, rotation of the adjustable knob 4 and consequent rotation of the nut 10 causes lengthwise axial movement of the front cam 11. The axial movement of the front cam 11 is transmitted by connecting rods 13 to the rear cam 12 which is also slidably mounted on the central shaft 5. As the front and rear cams 11, 12 move axially, axial movement of the barrel elements 3 is prevented by stopping member 16 which is fixed on the central shaft 5 by means of locking pin 19 (best seen in Figure 6), and the barrel elements 3 are caused to ride up or down the cams 11, 12, so that the barrel 2 expands or contracts radially. The cams 11, 12 are located in the front cam housing 18 and rear cam housing 17 respectively. Front cam housing 18 is fixed on the stopping member 16 and rear cam housing 17 is fixed to the central shaft 5 and allows air to flow therethrough to the interior of the barrel 2. By way of further explanation the co-operation of the barrel elements 3, cams 11, 12 and connecting rods 13 will now be described. The outer end of each barrel element 3 is provided with a pair of angled side slots which define an angled neck 20 for engaging in the inclined radial slots 21 in the front cam 11. The inner end of the barrel element 3 has an inclined portion 3g so that in combination the six barrel elements have a flared inner end, the largest diameter of which substantially matches the diameter of the handle 1 to allow a large flow of air to be introduced into the barrel. One large triangular aperture 3h is provided in each inclined portion which serves the dual purpose of delivering air to the outside surface of the curled hair and venting any air pressure build up to prevent overheating of the heater blower. In addition each inclined portion 3g finishes with an inclined neck 22 which engages in an inclined radial slot 23 in the rear cam 12. The connecting rods 13 are disposed, as best seen in Figure 7, alongside the central shaft 5 and are provided at each end with an outwardly turned right angle bend 13a which engage in holes 24, 25 in the front and rear cams 11, 12 respectively. Figures 8 and 9 show a modification in which the diameter of the barrel 102 is adjustable by means of a thumb-operated knob 104 at the inner end of the barrel. This arrangement allows the appliance to be held in one hand and the barrel diameter to be adjusted by the thumb of that hand. There is no locking mechanism to prevent rotation of the knob 104. The components comprise a shaft mounting bracket 130 fixed to the handle (not shown), a fixed central shaft 105, a front cam 111 fixed to the shaft 105, a rear cam 112 fixed to the shaft 105, a front cam housing 118, a washer 106, a cap 107 and bolt 131, barrel element 103, a barrel element stiffening rod 103f, and a heat shield 131 which fits inside the knob 104. An essential component of the mechanism is puller element 132. This component is prevented from rotating by the engagement of feet 132a in apertures 112a in the rear cam 112, but is free to move axially along shaft 105. The puller element 132 is provided with three equally spaced external lugs 132b which co-operate with helical grooves 104a on the inside face of the rotatable knob 104. When knob 104 is rotated, the co-operation of lugs 132b and grooves 104a causes the puller element 132 to move axially along the shaft 105. This axial movement is in turn transmitted to the barrel elements 103 by virtue of the engagement of the neck 103a of each barrel element 103 in a corresponding slot 132c in the puller element 132. As the barrel element 103 move axially they ride up or down the front rear cams 111, 112 causing the barrel 102 to expand or contract. The invention is not limited to warm air brushes. The invention may be applied to a variety of different hair care appliances, for examples hair curling irons.

Claims: An electrically powered hand held hair care appliance of the type comprising a handle (1) by means of which the appliance is held; a barrel (2) extending from the handle on which the hair to be curled is wound externally, the barrel (2) being hollow to allow fluid flow along the barrel, the barrel being provided with apertures (3d) 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, characterized in that the barrel (2) is formed by a number of elongate barrel elements (3) arranged in mutually parallel radial relationship to form a generally axially symmetric barrel, said elongate barrel elements (3) defining the inner and outer diameters of said barrel (2) and being movable radially inwardly together and radially outwardly together so as to contract and expand the inner and outer diameters of the barrel (2), the barrel elements (3) mutually combining to form a substantially closed barrel (2) when in the fully expanded state and a substantially closed barrel (2) with overlapping barrel elements (3a, 3c) in the contracted state, and the barrel elements (3) being provided with apertures (3d) which allow fluid to flow from the interior of the barrel (2) directly out to the hair when the barrel (2) is in the fully expanded, fully contracted or any intermediate state. A hair curling appliance according to claim 1 in which each barrel element (3) comprises an elongate base (3a), a row of brush teeth (3b) projecting radially outwardly from the base, a row of apertures (3d) in the base, and a lateral projection (3c) extending along one side of the elongate base (3a) for underlying the base (3a) of the adjacent barrel element (3) in the contracted or partially contracted state.

Inventors: MCDOUGALL GREGORY JOHN BLOCK A, MCDOUGALL, GREGORY JOHN, BLOCK A-B-C, 4TH FLOOR
Applicants: CHINA PACIFIC TRADE LTD, CHINA PACIFIC TRADE LTD.
Application year: 1991
Main classification: A45D2
IPC codes: A45D2, A45D1, A45D20