Hand-driers

Abstract: A hand-drier has an open mouth (3) for entry of hands into a glass tube (4) to be warmed by infra-red radiation from tungsten-halogen lamps (12) distributed round the outside of the tube (4). A fan (8) draws air into the tube (4) through the mouth (3) to pass over the warmed hands and be vented via openings (11). The tube (4) is mounted on rings (5) that also serve as baffles to block radiation from the lamps (12) passing out through the mouth (3).

Description: This invention relates to hand-driers of the kind in which means is provided for passing air over hands inserted through an external wall of the drier into a cavity defined therein, and one or more sources of radiant energy are located for warming the hands within the cavity. A hand-drier of the above-specified kind is known from JP-A-8168449 in which hands to be dried are inserted into a cavity in ducting of the drier, and air is blown by a fan through the ducting to pass from an exhaust opening over the hands while they are warmed by radiation from an infra-red source located in the exhaust opening. It is one of the objects of the present invention to provide a hand-drier of said above-specified kind that is of an improved form compared with that described in JP-A-8168449. According to the present invention there is provided a hand-drier of said above-specified kind characterised in that the one or more sources of radiant energy are located to radiate heat through a wall of the cavity to warm the hands inserted in the cavity, and that the air passed over the hands is drawn through the external wall into the cavity for entry into the drier from outside. The hand-drier of the invention has the advantage that the possibility of bacterial infection of the hands is significantly reduced. In particular, the air is drawn into the cavity to pass over the hands from outside the drier, rather than being blown over them by a fan via internal ducting. Accordingly, any bacteria lurking in the fan, ducting or other enclosed parts of the drier, are not conveyed to the warmed hands. A hand-drier in which air is drawn from the hand-drying zone into the drier, is described in IT-A-1242778. In this case, however, the air is drawn back into the drier from a rotating cushion of air that is created in the hand-drying zone by hot air injected into that zone from ducting within the drier. There is therefore in this case also, the possibility which is significantly reduced with the present invention, of the hands being infected while being dried. The radiant energy of the hand-drier of the invention may be infra-red radiation, and the air may be drawn into the cavity through the same opening in the external wall as used for insertion of the hands into the cavity. The cavity may be defined by a glass or other tube having an opening at one end for receiving the hands to be dried, and a fan or other means for drawing air into the cavity may in these circumstances be located at the other end of the tube for drawing air into the tube through the opening. The one or more sources of radiant energy may comprise a plurality of lamps that are located around the outside of the tube for applying heat to the hands by radiation through the wall of the tube. In these circumstances, one or more baffles may be located around the outside of the tube for blocking radiation from the lamps passing out through the opening at said one end. A hand-drier in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawing which shows the hand-drier in sectional-perspective view. Referring to the drawing, the hand-drier has an external metal-housing that is formed by a front fascia 1 and a rear main-casing 2. The fascia 1 provides an open mouth 3 for easy entry of the hands to be dried into a glass tube 4 of the drier. The tube 4 is mounted coaxially within rings 5 that are retained within the casing 2 spaced from one another on six rods 6. The rods 6 are secured to a base-plate 7 and extend through it to project rearwardly from the casing 2 for use in attaching the drier to a structural wall (for example, a washroom-wall). An electrically-powered centrifugal fan 8 mounted on the plate 7 is coupled to the inner end 9 of the tube 4 for drawing air through the mouth 3 into the tube 4 at its outer end 10. The mouth 3 is of venturi shape, not only to facilitate insertion of the hands into the tube 4, but more especially to promote stream-flow of air into and along the inside of the tube 4. After passing over the hands, the air drawn in is vented from the fan 8 radially through openings 11 at the rear of the casing 2. Six tungsten-halogen lamps 12 (only some shown) are mounted equidistant from one another around the outside of the glass tube 4. The lamps 12 are shrouded by individual elliptical reflectors 13 (only some shown) that direct the emitted light radially inwards through the wall 14 of the tube 4. The tube 4 is of a borosilicate glass to resist thermal shock and to have good transparency to the infra-red radiations from the lamps 12, so that the hands inserted in the tube 4 are warmed. The rings 5 in combination form a louvre structure that blocks radiation from the lamps 12 exiting through the mouth 3, without limiting to any substantial extent the radiation path to the hands. As a further safety feature, a perforated disc 16 is mounted on the rods 6 across the inner end 9 of the tube 4 as a finger-guard to the fan 8. Insertion of hands through the mouth 3 into the tube 4 is detected by a passive infra-red sensor (not shown) for activating the fan 8 and energising the lamps 12 while the hands remain entered (other forms of motion and proximity sensing may be used). Radiation from the lamps 12 warms the wet hands to evaporate the water, and the air sucked over the hands by the fan 8 quickly draws off the water vapour and vents it into the ambient atmosphere from the drier via the openings 11; the drier may be modified to incorporate filtering of the air and/or condensation of the water from it, before venting. The efficient and comfortable warming of the hands is facilitated by the reflectors 13 in focusing the radiation through the wall 14 onto the hands with an even distribution around the whole circumference of the tube 4. The lamps 12 provide instant heat when energised, and cool rapidly afterwards. Moreover, they provide visible light which passes through the wall 14 to provide a 'comfort' effect within the tube 4 for the user while the hands are being dried. The drying process is efficiently and quickly achieved with the drier described above. In particular, heat energy is directed to the wet hands for evaporating the water on them, and is not used primarily for heating the air. Furthermore, the air surrounding the hands, namely that into which evaporation takes place, is replaced continuously by fresh, unsaturated air from the ambient atmosphere so as to ensure that the evaporation process proceeds unhampered. The location of the hands within the partially-enclosed cavity formed by the tube 4 facilitates the rapid drawing off of water vapour without the necessity for movement of large volumes of air, and therefore enables a low-power, quiet fan to be used. Moreover, the possibility of bacterial infection of the hands during the drying process within the drier, is significantly reduced since the air contacting the hands is directly from the ambient atmosphere. It is notable in this respect that the air contacting the hands passes through the fan 8 and other enclosed parts of the drier where bacteria might lurk, only following such contact.

Claims: A hand-drier wherein means (8) is provided for passing air over hands inserted through an external wall (1) of the drier into a cavity (4) defined therein, and wherein one or more sources (12) of radiant energy are located for warming the hands within the cavity (4), characterised in that the one or more sources (12) of radiant energy are located to radiate heat through a wall (14) of the cavity (4) to warm the hands inserted in the cavity (4), and that the air passed over the hands is drawn through the external wall (1) into the cavity (4) for entry into the drier from outside. A hand-drier according to Claim 1 wherein the one or more sources of radiant energy are one or more sources (12) of infra-red radiation. A hand-drier according to Claim 1 or Claim 2 wherein the air is drawn into the cavity (4) through the same opening (3) in the external wall (1) as used for insertion of the hands into the cavity (4). A hand-drier according to Claim 3 wherein the cavity is defined by a tube (4) having an opening (10) at one end for receiving the hands to be dried, and wherein the means (8) for drawing air through the cavity is located at the other end (9) of the tube (4) for drawing air into the tube (4) through the opening (10) at said one end. A hand-drier according to Claim 4 wherein the one or more sources of radiant energy comprise a plurality of lamps (12) that are located around the outside of the tube (4) for applying heat to the hands by radiation through the wall (14) of the tube (4). A hand-drier according to Claim 5 wherein the lamps are tungsten-halogen lamps (12). A hand-drier according to Claim 5 or Claim 6 wherein the lamps are shrouded by reflectors (13) to direct the emitted radiation radially inwards through the wall (14) of the tube (4) onto the hands. A hand-drier according to any one of Claims 4 to 7 wherein one or more baffles (5) are located around the outside of the tube (4) for blocking radiant energy from said sources (12) passing out through the opening (10) at said one end. A hand-drier according to any one of Claims 4 to 8 including means defining an open mouth (3) of venturi form leading into said opening (10) at said one end for promoting stream-flow of air into and along the tube (4). A hand-drier according to any one of Claims 4 to 9 including means for filtering and/or condensing water from the air drawn through the tube (4), before it is vented from the drier.

Inventors: WHITE MATTHEW EDWARD THOMAS, WHITE, MATTHEW EDWARD THOMAS
Applicants: WHITE MATTHEW EDWARD THOMAS, WHITE, MATTHEW EDWARD THOMAS
Application year: 2001
Main classification: A47K10
IPC codes: A47K10