Hand Dryer

BACKGROUND OF THE INVENTION

The invention relates to a hand dryer comprising a blower motor arranged in a housing and blowing out air through an exit opening.

Such hand dryers have an exit opening through which the air stream produced by the blower motor will exit and with which the hands of the user, for example, after washing hands, are dried. However, most of the air that is exiting through the exit opening does not reach the hands to be dried but flows laterally past them. Therefore, the drying process requires a considerable amount of time. Moreover, the efficiency is not optimal.

It is therefore an object of the present invention to design the hand dryer of the aforementioned kind in such a way that the drying air can be used optimally so that only a minimal amount of time is required for drying hands.

SUMMARY OF THE INVENTION

In accordance with the present invention, this is achieved in that the hand dryer in accordance with the present invention has at least one additional exit opening and in that the air streams that are exiting from the exit openings meet or converge in a drying area for the hands.

The hand dryer according to the invention has more than one exit opening. These exit openings are provided such that the air streams exiting therefrom meet or converge in a drying area. The drying area is designed such that the entire hand is enclosed. In this way, the drying process is significantly accelerated. Since the air streams meet in the drying area, the user can easily find the optimal point for drying his hands. The air that is employed for drying is concentrated in the drying area so that by far most of the air is employed for drying the hands and only a minimal amount of the air flows past the hands to be dried. The drying time is thus significantly shortened. It is only half as long as the drying time of conventional hand dryers.

In the drying area, the air streams form advantageously a swirl field that ensures a quick drying action.

Advantageously, the exit openings are arranged such that their axes or exit flow directions extend angularly to each other. In this case, the axes of the exit openings meet approximately at a point. In this way, it is achieved that the air exiting from the exit openings reaches the drying area in a targeted fashion.

In order to obtain a simple configuration, it is advantageous when the exit openings are positioned in wall sections of a wall, wherein the wall sections are angularly arranged relative to each other. Such a wall can be manufactured easily in that the exit openings in this case can be simply formed by simple openings that can be produced in the wall by a stamping process, for example.

In one embodiment, these wall sections are flat and positioned at an obtuse angle relative to each other. In this case, the wall is comprised, for example, of an appropriately angled sheet metal part wherein the exit openings can be stamped into the wall sections. This stamping process is advantageously done before bending the sheet metal part.

The angular position of the axes of the exit openings can be achieved also in that the wall sections are part of a continuously curved wall. Depending on the position of the exit openings on this curved wall, different angles of the opening axes result. The radius of curvature of such a wall is selected such that the axes of the exit openings meet approximately at a point. The curved wall can be produced also in a simple and inexpensive way by bending a sheet metal part.

In order for the air to exit approximately in the same quantity from all exit openings, at a spacing upstream of the exit openings at least one distributor for the air is provided. It ensures that the air is approximately uniformly supplied to the exit openings.

The distributor is advantageously plate-shaped and can be, for example, formed by a simple sheet metal part.

The distributor has a course that corresponds to the course or extension of the wall in which the exit openings are located. Accordingly, the distributor, for example, can be comprised of distributor sections that are positioned angularly to each other or the distributor can be, for example, embodied with a continuous curvature.

In an advantageous embodiment, the distributor delimits with neighboring wall sections an acceleration space for the air. In the acceleration space, the air that is exiting from the blower motor is accelerated in the direction toward the exit openings. In this way, it is achieved that the air with an appropriately high speed will exit from the exit openings and flow into the drying area. The high flow speed in the drying area ensures that the hands will be dried within a very short period of time.

A simple configuration results when the acceleration space narrows in the flow direction of the air. As a result of the cross-sectional narrowed section of the acceleration space, the desired acceleration of the air is achieved.

In order for the individual exit openings to be supplied with approximately the same air quantities, upstream of the exit openings in a preferred way a common flow space is provided which in the flow direction of the air is positioned downstream of the acceleration space. In this way, the air after acceleration in the acceleration space reaches the common flow chamber before it flows out to the exterior through the exit openings.

In a preferred embodiment, as a blower motor a high-pressure blower motor is used. It can have a delivery rate of, for example, approximately 30 l per second. With such a high-pressure blower motor, very high flow speeds can be obtained that contribute in an advantageous way to short drying times.

The exit openings can be embodied as grid or aperture plates.

In another advantageous embodiment the exit openings are slit-shaped.

In another embodiment, the exit openings can be formed by a plurality of small holes in the form of small bores and/or small slits in the wall.

Optimal drying results, in particular short drying times, are produced when the exit surface area of the exit openings is sized such that the exit flow speed of the air is greater than approximately 35 m per second.

Advantageously, the air stream that is exiting from the exit openings is blown away from the user slightly at a slant so that the water droplets that are blown away will not reach the clothing of the user.

The subject matter of the present application not only results from the individual claims but also from the features and specifications disclosed in the drawings and in the description. Even though these features and specifications may not be claimed, they are considered important to the invention inasmuch as they, individually or in combination, are new relative to the prior art.

Further features of the invention can be taken from the claims, the description and the drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic illustration in longitudinal section of the hand dryer according to the invention.

FIG. 2 is a view in the direction of arrow II in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The hand dryer is, for example, attached to a mounting plate 1 that is fastened to a wall or the like, for example, connected by screws. The hand dryer has a housing 2 having an interior in which at least one blower motor 3 is arranged with which in a known manner an air stream can be generated that exits downwardly from the housing 2.

An air guide 4 is connected to the bottom end of the housing 2 and has a rectangular cross-section (FIG. 2). It is provided with three exit openings 5 to 7. They each have a circular cross-section and advantageously are of the same size.

The air guide 4 extends initially continuously away from the housing in the flow direction of the air. The air guide 4 has parallel longitudinal sidewalls 8, 9 that are connected to each other by narrow sidewalls 10, 11. The sidewalls each are comprised of two wall sections 10a, 10b; 11a, 11b that are positioned at an obtuse angle relative to each other. The wall sections 10a, 11a adjoin the exit end 23 of the housing 2 and diverge in the flow direction of the air. The wall sections 10a, 11a are longer than the wall sections 10b, 11b that converge relative to each other in the flow direction of the air. The wall sections 10b, 11b are connected to each other by a terminal wall 12 that connects also the longitudinal sidewalls 8, 9 of the air guide 4 with each other. The terminal wall 12 is comprised of three wall sections 12a, 12b, 12c that are positioned at an obtuse angle to each other. The wall sections 12a, 12c adjoin approximately at a right angle the wall sections 10b, 11b and diverge in the flow direction of the air. The central wall section 12b is positioned centrally and perpendicularly to the longitudinal axis of the housing 2.

Each wall section 12a, 12b, 12c is provided with one of the exit openings 5, 6, 7. The axes 13 to 15 of the exit openings 5 to 7 are positioned at an acute angle to each other. The wall sections 12a to 12c and the exit openings 5 to 7 provided therein are oriented such that the axes 13 to 15 meet each other in a drying location 16. In this area, the hands to be dried are located when using the hand dryer. The wall sections 12a to 12c are oriented such that the spacing of the drying location 16 from the exit openings 5 to 7 is so large that a satisfactorily strong air stream will impinge on the hands to be dried so that an effective drying action is ensured. The hands to be dried are within the drying area that is schematically indicated by the circle 17 in FIG. 1 that is so large that the hands are completely or to a significant degree enclosed therein. The drying area 17 is positioned external to the hand dryer.

The air guide 4 has a width 18 that is smaller than the width 19 of the housing 2. The housing 2 has in the illustrated embodiment advantageously a circular cross-section so that the width 19 corresponds to the diameter of the housing 2. The housing 2 can also have any other suitable cross-section, however.

The maximum length 20 of the air guide 4 is greater than the housing width 19. In the exit area, the length 21 of the air guide 4 is also greater than the housing width 19. The length 21 is determined by the spacing between the transition of the wall sections 12a, 12c into the wall sections 10b, 11b.

It should be noted that the described dimensional conditions are not mandatory but that the air guide 4 can also have different dimensions, depending on the field of use of the hand dryer. Also, the described configuration of the air guide 4 is advantageous but the air guide as a whole can also be of a different configuration. For example, it is possible that the air guide 4 has only two, or more than three, exit openings at the exit end. The air guide and the appropriate number of exit openings is to be provided such that the hands located within the drying area 17 are dried quickly and reliably within a very short period of time. Also, the terminal wall 12 must not be comprised of the angularly positioned wall sections 12a to 12c. For example, the terminal wall 12 can also be continuously curved to form a concave shape. In such a wall configuration, the exit openings 5 to 7 can also be arranged with their axes positioned angularly relative to each other.

Within the air guide 4 there is a distributor plate 22 through which the air, exiting from the exit end 23 of the housing 2 and flowing intoo the air guide 4, is distributed such that from each one of the exit openings 5 to 7 the same air quantity exits, respectively. The distributor plate 22 extends between the two longitudinal sidewalls 8, 9 of the air guide 4 and is attached thereto in a suitable way. The distributor plate 22 is positioned centrally in the air guide 4 and has a central section 22a that extends parallel to the central wall section 12b and is located in the area above the central exit opening. The central plate section 22a is adjoined by the sections 22b and 22c at an obtuse angle, the sections 22b, 22c diverge in the direction toward the terminal wall 12 of the air guide 4. The sections 22b, 22c are positioned at a spacing opposite the all sections 10a, 11a and at an acute angle relative thereto. In this way, between the sections 22b, 22c and the wall sections 10a, 11 a positioned at a spacing opposite thereto, an acceleration space 24, 25 is formed, respectively, which narrows in the flow direction of the air. Accordingly, the air in the spaces 24, 25 is accelerated.

The distributor plate 22 ensures that the air stream that is exiting from the exit end 23 of the housing is distributed uniformly so that through the exit openings 5 to 7 approximately the same air quantities are exiting. The air that is flowing through the acceleration spaces 24, 25 flows into a common flow space 26. This flow space 26 is located in the area above the exit openings 5 to 7 and, in the flow direction, is delimited in downward direction by the terminal wall 12 and in opposite direction thereto partially by the distributor plate 22.

The air stream is heated, as is known in the art, in order to speed up the drying process. For heating the air stream, for example, a heater coil can be used.

For operating the hand dryer, an electronic unit 27 illustrated only schematically in FIG. 1 is used. The hand dryer is advantageously designed such that it is automatically switched on when hands are located in the drying area 17. Such an automatic actuation is known in hand dryers and is therefore not described in more detail in this context. As soon as the hands are moved out of the drying area 17, the hand dryer is automatically switched off. However, it is also possible that the hand dryer, as soon as the hands to be dried reach the drying area 17, is automatically switched on and the supply of drying air is time-controlled so that the hand dryer is automatically switched off after lapse of the adjusted drying time period.

Since the air streams that are exiting from the exit openings 5 to 7 are directed onto the drying area 17, by far most of the air reaches the hands to be dried so that the drying time in comparison to conventional hand dryers is significantly reduced. The distributor plate 22 ensures that the airstreams exit at a high speed and in approximately the same quantity through the exit openings 5 to 7; this provides for a quick drying action of the hands. The high air acceleration is achieved in a simple way by acceleration spaces 24, 25. The adjoining flows space 26 ensures in the described way that the accelerated air is uniformly exiting to the exterior through the exit openings. Advantageously, the exit speed is greater than approximately 35 m per second.

In the illustrated embodiment, the exit openings 5 to 7 are arranged in a line adjacent to each other (FIG. 2). However, it is also possible to arrange the exit openings such that their axes are positioned on a circle, for example. In this context, the axes are positioned angularly relative to each other such that the air streams meet within the drying area 17.

The number of exit openings depends also on their diameter. The smaller the opening diameter of the exit openings 5 to 7, the more exit openings are provided so that the required air quantity reaches the drying area 17.

The exit openings 5 to 7 are of a nozzle configuration and, apart from the disclosed shape, can also be designed as grid or aperture plates or as slits. The exit openings can also be provided in the form of a plurality of small bores and/or small slits in the wall 12.

The arrangement of the exit openings 5 to 7 is selected advantageously such that the air streams will exit from the exit openings slightly at a slant away from the user.

Advantageously, as a blower motor preferably a high-pressure blower motor is employed whose delivery rate is within a magnitude of 30 l per second, for example.

The specification incorporates by reference the entire disclosure of German priority document 20 2012 006 802.4 having a filing date of Jul. 11, 2012.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.