GB2422309A

GB2422309A - Hair dryer with two fans

Info

Publication number: GB2422309A
Application number: GB0600428A
Authority: GB
Inventors: Mauro Labirio
Original assignee: BELL Srl
Current assignee: BELL Srl
Priority date: 2005-01-24
Filing date: 2006-01-11
Publication date: 2006-07-26
Anticipated expiration: 2026-01-11
Also published as: GB2422309B; ITPC20050001U1; GB0600428D0; FR2882233B3; FR2882233A3; ES1062676Y; DE202006000438U1; ES1062676U

Abstract

A hair dryer comprises a generally tubular body containing a heater 6 and a motor 8 and having a hot air outlet 5 characterised in that it further comprises first 10 and second 12 fans installed in series and driven by the motor. The tubular body may have a constriction 13 immediately upstream of the second fan so as to produce an increase in the pressure of the air leaving the hot air outlet without substantially increasing the overall size of the hair dryer when compared to conventional devices with a single fan and no constriction.

Description

IMPROVED HAIRDRYER

This invention relates to an improved hairdryer, of the type with a nozzle attachment designed to reduce the cross-sectional area of the hot air outlet, characterised in that it includes means designed to increase the pressure of the outgoing air in order to keep the airflow constant even with the nozzle attached.

This purpose is achieved as a result of the particular configuration of the hairdryer, wherein two fans are fitted in series, and the body in which the motor and fans are housed presents a constriction immediately upstream of the second fan so that the air blown by the first fan is already at a higher pressure when it enters the second fan, thus producing a significant increase in the pressure of the air output by the appliance. All these characteristics are achieved without increasing the overall size of the hairdryer, which is therefore particularly practical and convenient to use.

All known hairdryers have a structure which comprises a tube with a freshair suction inlet and a heated-air outlet and, inside said tube, a fan with an electric motor, and a heating element located downstream of the fan. The air outlet is relatively large, to allow the passage of a good airflow distributed over a sufficiently large area.

However, professional users of these appliances, such as hairdressers, often prefer to have a more concentrated jet of air available, in order to perform particular treatments on a lock of hair.

The solution adopted generally involves attaching to the hot-air outlet of the hairdryer a nozzle shaped so as to present a narrow, flattened outlet opening that produces a laminar jet of air.

However, in practice, this solution involves creating a constriction on the outlet, and the resulting pressure drop generates a significant reduction in airflow, leading to overheating of the element and the inner parts, with the result that the protective devices are often triggered, interrupting the operation of the hairdryer.

In order to remedy this problem, hairdryers have been designed containing systems that reduce the power supply to the element, and consequently its temperature, when the nozzle is attached. However, in addition to a Jo certain complexity of manufacture, this does not solve the problem of airflow reduction caused by the constriction of the outlet nozzle.

The present invention now solves this problem, by providing devices that increase the pressure of the air conveyed to the heating element and thence to the hairdryer outlet, so as to maintain an airflow sufficient to remove the quantity of heat produced from the element, even when a nozzle that reduces the cross-sectional area of the outlet is attached to it.

The present invention solves this problem without using complex devices, and above all without affecting the size or manageability of the appliance.

More particularly, the invention uses a twin-shaft electric motor to which two fans are fitted in series; the first fan sucks in air from the outside, and conveys it towards a constriction that leads into the entrance area of the second fan.

The pressure of the air blown towards the constriction increases, and under these conditions the air is conveyed to the second fan, which directs it towards the outlet.

Thus a sufficient airflow can be maintained by increasing the air pressure, even when a nozzle that reduces the cross-sectional area of the outlet is attached to the hairdryer.

This invention will now be described in detail, by way of example but not of limitation, by reference to the annexed figures wherein: * figure 1 is a view of the hairdryer according to the invention, assembled, * figure 2 shows a nozzle designed to be attached to the hairdryer; * figure 3 schematically illustrates a hairdryer according to the invention, in cross-section.

As shown in figure 1, no. 1 indicates the body of a hairdryer according to the invention, the casing of which is substantially constituted by a tube 2, fitted with a handle 3, at the extremities of which there are a fresh-air inlet 4 and a hot-air outlet 5.

A heating element 6, such as a wire heating element, inserted in tubular extremity 7 of body 2, and an electric motor 8, are housed in body 2.

Motor 8 has a first output shaft 9 on which a centrifugal fan 10 is mounted, and a second output shaft 11, on the opposite side, on which a second fan 12 is mounted.

Fans 10 and 12 are the centrifugal type, wherein air is sucked in from a central area shown as C in the figure and expelled tangentially, as indicated by arrows F in figure 2.

Fan 10, which is located upstream, sucks air from the interior and conveys it towards fan 12, which is located downstream.

Tube 2 is shaped internally as illustrated in figure 2, with a constriction 13 that divides the tube into two adjacent bodies, shown as 14 and 15.

The motor and fan 10 are housed in the first of said bodies, while fan 12 and heating element 6 are housed in the second.

The constriction is located at the point of entry of the air conveyed to fan 12, and the wall of section 14 of the tube has a curved shape in cross- section that narrows increasingly towards constriction 13.

The device operates as follows.

When the device is switched on, the electrical current powers motor 8 and heating element 6, which begins to heat up.

Motor 8 causes fans 10 and 12 to rotate simultaneously. Fan 10 sucks in air from the outside through inlet C, and expels it perimetrically, against the wall of section 14 of tube 2.

The air is blown forwards towards the front of the appliance, where the cross-sectional area of body 14 narrows, causing a consequent increase Is in the pressure of the air originating from fan 10.

The air, thus partly compressed, passes through constriction 13 and is conveyed to fan 12, which directs it towards heating element 6 and outlet of the appliance.

As a result of the compression exercised by fan 10 on the air conveyed to fan 12, a jet of air at higher pressure is obtained, which guarantees a sufficient airflow even when a nozzle is attached to outlet 5 and causes a certain pressure drop by reducing the cross-sectional area of the outlet.

The manufacture of hairdryer according to the invention requires no special components, as the motors used for conventional hairdryers can be employed, provided that the shaft is designed to project from two sides rather than one, so that the second fan can be inserted in the space generally left between the heating element and the motor.

The size and manageability of the appliance therefore remain substantially unchanged, and the weight which professionals are used to handling remains the same.

Different forms of embodiment relating to the same solution idea could be devised, all of which should be deemed to fall within the ambit of this invention.

Claims

1) Hairdryer of the type comprising a body constituted by a tube that houses a motor which drives means designed to generate an airflow and, downstream of said means, a heating device constituted by an electrical heating element installed upstream of a hot-air outlet, characterised in that said means designed to generate an airflow are constituted by two fans installed in series and driven by the same motor.

2) Hairdryer as claimed in claim 1, wherein a first fan sucks in fresh air from the outside and conveys it towards said second fan, characterised in that said tube which houses the motor and the fans presents a constriction immediately upstream of the area in which air enters said second fan, so as to increase the pressure of the air blown by said first fan towards said second fan.

3) Hairdryer as claimed in claim 2, characterised in that said first and second fans are centrifugal fans.

4) Hairdryer as claimed in any of the preceding claims, characterised in that it includes a twin-shaft motor, said fans being fitted on the common shaft of said motor, at opposite ends thereof.

5) Hairdryer characterised in that it includes: * a body constituted by a tube (2) featuring a fresh air inlet, a hot-air outlet and a central constriction (13) that divides the tube into two bodies (14) and (15); * an electric motor (8) installed in one of said bodies and a heating element (6) installed in the second of said bodies, upstream of the hotair outlet; * a first fan (10) fitted on shaft (9) of said motor upstream thereof, close to fresh-air inlet (C); * a second fan (12), fitted on motor shaft (11) on the opposite side of the motor to first fan (10), immediately downstream of constriction (13) s which divides the tube into two bodies (14, 15), which said constriction forms an opening at the point of entry to said second fan, said first and second fans both being centrifugal fans.