|Numéro de publication||US20080301970 A1|
|Type de publication||Demande|
|Numéro de demande||US 11/997,305|
|Date de publication||11 déc. 2008|
|Date de dépôt||12 juin 2006|
|Date de priorité||30 juil. 2005|
|Autre référence de publication||CN101232832A|
|Numéro de publication||11997305, 997305, PCT/2006/2144, PCT/GB/2006/002144, PCT/GB/2006/02144, PCT/GB/6/002144, PCT/GB/6/02144, PCT/GB2006/002144, PCT/GB2006/02144, PCT/GB2006002144, PCT/GB200602144, PCT/GB6/002144, PCT/GB6/02144, PCT/GB6002144, PCT/GB602144, US 2008/0301970 A1, US 2008/301970 A1, US 20080301970 A1, US 20080301970A1, US 2008301970 A1, US 2008301970A1, US-A1-20080301970, US-A1-2008301970, US2008/0301970A1, US2008/301970A1, US20080301970 A1, US20080301970A1, US2008301970 A1, US2008301970A1|
|Inventeurs||Paul Cedric Campbell Hackwell, Frederic Nicolas|
|Cessionnaire d'origine||Dyson Technology Limited|
|Exporter la citation||BiBTeX, EndNote, RefMan|
|Référencé par (7), Classifications (5), Événements juridiques (1)|
|Liens externes: USPTO, Cession USPTO, Espacenet|
This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2006/002144, filed Jun. 12, 2006, which claims the priority of United Kingdom Application Nos. 0515739.1, filed Jul. 30, 2005, and 0600880.9, filed Jan. 17, 2006, the contents of which prior applications are incorporated herein by reference.
The invention relates to drying apparatus which makes use of a narrow jet of high velocity, high pressure air to dry an object, including part of the human body. Particularly, but not exclusively, the invention relates to a hand dryer in which the air jet is emitted through a slot-like opening in the casing of the hand dryer.
The use of air jets to dry hands is well known. Examples of hand dryers which emit at least one air jet through a slot-like opening are shown in GB 2249026A, JP 2002-034835A and JP 2002306370A. However, in practice it is very difficult to achieve an evenly distributed airflow of sufficiently high momentum to dry the user's hands efficiently in an acceptably short length of time. The prior art does not achieve this.
It is an object of the invention to provide drying apparatus which, in use, emits an air jet through a slot-like opening which is capable of drying an object in a short time as compared to the prior art. It is another object to provide a hand dryer which is capable of drying the user's hands in a short time in comparison to the prior art. It is a further object of the invention to provide an improved hand dryer in which the drying efficiency is improved in comparison to the prior art.
A first aspect of the invention provides drying apparatus having a casing, a cavity formed in the casing for receiving an object, a fan located in the casing and capable of creating an airflow, and at least one slot-like opening communicating with the fan and arranged in the casing so as to direct an airflow transversely across the cavity, wherein the slot-like opening is formed between opposing walls which approach one another at an angle of between 10° and 20°.
In a preferred embodiment, the angle between the walls of the slot-like opening is substantially 14°. This angle has been found to be advantageous in that the momentum of the airflow emitted through the slot-like opening is greatly increased in comparison to that of the prior art devices. This increases the efficiency of the dryer by virtue of the fact that more water is blown from the object during each pass thereof through the airflow exiting the slot-like openings.
A second aspect of the invention provides drying apparatus having a casing, a cavity formed in the casing for receiving an object, a fan located in the casing and capable of creating an airflow, and two opposing slot-like openings communicating with the fan via ducting and arranged in the casing so as to direct an airflow transversely across the cavity, wherein the ducting has a first cross-section in the vicinity of the fan whose dimensions are similar in all directions and a slot-like cross-section in the vicinity of the openings, the transition between the said cross-sections being gradual and smooth.
Preferably, the total cross-sectional area of the ducting is substantially constant between the fan and a point immediately upstream of the slot-like openings. This minimises losses within the ducting and enhances the efficiency of the fan.
An embodiment of the invention in the form of a hand dryer will now be described with reference to the accompanying drawings, in which:
Referring firstly to
The cavity 30 has a front wall 34 and a rear wall 36 which delimit the cavity 30 to the front and rear respectively. Located in the lowermost end of the cavity 30 is a drain 38 which communicates with a reservoir (not shown) located in the lower part of the casing 12. The purpose of the drain and reservoir will be described below.
As shown in
The air ducts 50, 52 are arranged to conduct air from the fan 40 to a pair of opposed slot-like openings 60, 62 which are located in the front and rear walls 34, 36 respectively of the cavity 30. The slot-like openings 60, 62 are arranged at the upper end of the cavity 30 in the vicinity of the cavity entrance 32. The slot-like openings 60, 62 are each configured so as to direct an airflow generally across the cavity entrance 32 towards the opposite wall of the cavity 30. The slot-like openings 60, 62 are offset in the vertical direction and angled towards the lowermost end of the cavity 30.
Each pair of walls 54 a, 54 b, 56 a, 56 b is arranged so that the respective walls approach one another as they approach the respective slot-like opening 60, 62. If an imaginary axis 70 is considered to lie midway between each pair of walls, as is shown in
Sensors 64 are positioned in the front and rear walls 34, 36 of the cavity 30 immediately below the slot-like openings 60, 62. These sensors 64 detect the presence of a user's hands which are inserted into the cavity 30 via the cavity entrance 32 and are arranged to send a signal to the motor when a user's hands are introduced to the cavity 30. As can be seen from
As can be seen from
The air ducts 50, 52 form part of the ducting 90 which lies between the fan 40 and the slot-like openings 60, 62. A perspective view of the ducting 90 is shown in
The ducting 90 is designed so that the cross-sectional area of the ducting 90 gradually transforms from the generally square (or circular) shape of the chamber 94 to the slot-like shape of the openings in a smooth and gradual manner. Immediately downstream of the chamber 94, the ducting divides into the air ducts 50, 52, at the upstream end of which the cross-sectional area is still generally square in shape—ie, the breadth and depth of the cross-section are substantially similar. However, the cross-section changes gradually with distance from the chamber 94 so that the breadth of each duct 50, 52 increases as the depth reduces. All of the changes are smooth and gradual to minimise any frictional losses.
At a point 98 immediately upstream of each of the slot-like openings 60, 62, the cross-sectional area of each of the air ducts 60, 62 begins to decrease so as to cause the velocity of the airflow travelling towards the slot-like openings 60, 62 to increase dramatically. However, between the chamber 94 and the point 98 in each air duct 50, 52, the total cross-sectional area of the ducting (ie. the combined cross-sectional area of the air ducts 50 and 52) remains substantially constant.
The hand dryer 10 described above operates in the following manner. When a user's hands are first inserted into the cavity 30 through the cavity entrance 32, the sensors 64 detect the presence of the user's hands and send a signal to the motor to drive the fan 40. The fan 40 is thus activated and air is drawn into the hand dryer 10 via the air inlet 44 at a rate of approximately 20 to 40 litres per second and preferably at a rate of least 25 to 27 litres per second, more preferably air is drawn into the hand dryer 10 at a rate of 31 to 35 litres per second. The air passes through the filter 46 and along the fan inlet 42 to the fan 40. The airflow leaving the fan 40 is divided into two separate airflows; one passing along the front air duct 50 to the slot-like opening 60 and the other passing along the rear air duct 52 to the slot-like opening 62.
The airflow is ejected from the slot-like openings 60, 62 in the form of very thin, stratified sheets of high velocity, high pressure air. As the airflows leave the slot-like openings 60, 62, the air pressure is at least 15 kPa and preferably approximately 20 to 23 kPa. Furthermore, the speed of the airflow leaving the slot-like openings 60, 62 is at least 80 m/s and preferably at least 100 or 150 m/s, more preferably approximately 180 m/s. Because the size of the slot-like opening 62 located at the end of the rear duct 52 is greater than the size of the slot-like opening 60 located at the end of the front duct 50, a larger volume of air is emitted from the duct 52 than from the duct 50. This provides a greater mass of air for drying the backs of the user's hands which is advantageous.
The two thin sheets of stratified, high velocity, high pressure air are directed towards the surfaces of the user's hands which, during use, are inserted fully into the cavity 30 and are subsequently withdrawn from the cavity 30 via the cavity entrance 32. As the user's hands pass into and out of the cavity 30, the sheets of air blow any existing water off the user's hands. This is achieved reliably and effectively because of the high momentum of the air leaving the slot-like openings 60, 62 and because the airflow is evenly distributed along the length of each slot-like opening 60, 62.
Each stratified sheet of air is directed towards the wall of the cavity 30 which is remote from the slot-like opening through which the respective sheet of air is emitted. Because the slot-like openings 60, 62 are also inclined towards the lowermost end of the cavity 30, the emitted airflows are directed into the cavity 30. This reduces the risk of turbulent air movement being felt by the user outside the casing, eg in the user's face.
It is envisaged that it will take only a small number of “passes” of the hand dryer described above to dry a user's hands to a satisfactory degree. (By “pass”, we mean a single insertion of the hands into the cavity and subsequent removal therefrom at a speed which is not unacceptable to an average user. We envisage that a single pass will have a duration of no more than 3 seconds.) The momentum achieved by the airflows is sufficient to remove the majority of water found on the surface of the user's hands after washing during a single pass.
The water removed by the airflows is collected inside the cavity 30. Each airflow will rapidly lose its momentum once it has passed the user's hands and the water droplets will fall to the lower end of the cavity 30 under the forces of gravity whilst the air exits the cavity 30 either through the cavity entrance 32 or via the open sides of the cavity 30. The water, however, is collected by the drain 38 and passed to a reservoir (not shown) where it is collected for disposal. The reservoir can be emptied manually if desired.
Alternatively, the hand dryer 10 can incorporate some form of water dispersal system including, for example, a heater for evaporating the collected water into the atmosphere. The means by which the collected water is dispersed does not form part of the present invention.
In an alternative embodiment, the slot-like openings 60, 62 can be arranged so that the sheets of air which are emitted therefrom are directed generally along planes which are substantially parallel to one another. This minimises the amount of turbulent flow present inside the cavity 30 whilst the drying apparatus is in use.
In a further alternative embodiment shown in
Preferably, the width of the slot-like opening in the rear wall varies gradually, increasing towards the mid point of the opening, at centre line A-A of cavity entrance 32.
In this alternative embodiment it is preferred that the variation in width of the opening is achieved by varying the distance of the upper wall of the slot-like opening away from the lower wall, in the shape of a curve, preferably in a smoothly curving shape. More preferably the curve is symmetrical about centre line A-A of the cavity entrance 32. Preferably the maximum width R of the opening is at centre line A-A and is 0.7 mm.
Preferably, the width r is substantially constant in regions F and G with the varying width region (region E in
In region E of the hand dryer the width of the slot-like opening 62 is greater than the width of the slot-like opening 62 in regions F and G. The increase in size of the slot-like opening 62 provides a greater mass of air 80 from rear duct 52 for drying the backs of the user's hands in the thumb and forefinger area which is advantageous. The greater mass of air in region E and the momentum achieved by the airflow is sufficient to remove the majority of water found on the backs of the user's hands after washing during a single pass.
The invention is not intended to be limited to the precise detail of the embodiments described above. Modifications and variations to the detail which do not alter the scope of the invention will be apparent to a skilled reader. For example, the shape of the cavity 30 and its entrance 32 may be altered without departing from the essence of the present invention.
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|US8347522 *||26 juin 2006||8 janv. 2013||Dyson Technology Limited||Drying apparatus|
|US8490291 *||13 juin 2006||23 juil. 2013||Dyson Technology Limited||Dryer|
|US8544186 *||11 mai 2011||1 oct. 2013||Hokwang Industries Co., Ltd.||Hand dryer with annular air exhaust|
|US20120285033 *||15 nov. 2012||Chi-Chin Hsu||Hand dryer with annular air exhaust|
|Classification aux États-Unis||34/202|
|Classification internationale||A47K10/00, A47K10/48|
|6 mars 2008||AS||Assignment|
Owner name: DYSON TECHNOLOGY LIMITED, UNITED KINGDOM
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HACKWELL, PAUL CEDRIC CAMPBELL;NICOLAS, FREDERIC;REEL/FRAME:020611/0451;SIGNING DATES FROM 20080131 TO 20080211