Housing with access passage

Abstract

A housing for a device an outside and an inside, as well as an access passage for access from the outside of the housing to a component of the device inside the housing. The access passage comprises an outer opening section, and an inner drainage channel. The drainage channel is arranged below the outer opening section, which has vertical side walls extending inwardly from the outside of the housing. Each sidewall has a top width (W.sub.T) and a bottom width (W.sub.B), the top width (W.sub.T) being narrower than the bottom width (W.sub.B). The sidewalls provide a guiding surface for a liquid entering the access passage, such that the liquid is guided towards the drainage channel.

Claims

1. A housing for a device, the housing having an outside and an inside, the housing further having an access passage for access from the outside of the housing to a component of the device inside the housing, wherein the access passage comprises: an outer opening section providing access from outside of the housing to the component, and an inner drainage channel inside the housing connecting the outer opening section to a drainage opening in the housing, the drainage channel being arranged below the outer opening section, the outer opening section having vertical side walls extending inwardly from the outside of the housing, each sidewall having a top width at a top of the sidewall and a bottom width at a bottom of the sidewall closer to the drainage channel, the top width being narrower than the bottom width, the sidewalls providing a guiding surface for a liquid entering the access passage, such that the liquid is guided towards the drainage channel.

2. The housing according to claim 1, wherein a cross section of the drainage channel is smaller than a cross section of the outer opening section.

3. The housing according to claim 1, further comprising a guiding groove, arranged to guide the liquid from the outer opening section to the drainage channel.

4. The housing according to claim 3, wherein a cross section of the guiding groove is smaller than a cross section of the outer opening section and larger than a cross section of the drainage channel.

5. The housing according to claim 1, wherein a cross section of the drainage channel is rectangular.

6. The housing according to claim 1, wherein each sidewall is provided by a wedge-shaped wall portion.

7. A device comprising a housing according to claim 1, and a component arranged inside the housing, wherein the component is accessible through the access passage.

8. The device according to claim 7, wherein the component is an input component or an output component.

9. The device according to claim 8, wherein the input component is a microphone.

10. The device according to claim 7, wherein the component is arranged above the outer opening section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The embodiments will now be described in more detail by way of example and with reference to the accompanying schematic drawings, in which:

(2) FIG. 1 is a front view of a door station having a housing according to an embodiment,

(3) FIG. 2 is a perspective view of a portion of the housing of FIG. 1, and

(4) FIG. 3 is an enlarged cross-sectional view of the housing portion of FIG. 2, showing parts of the device inside the housing.

DETAILED DESCRIPTION OF EMBODIMENTS

(5) In FIG. 1, a housing 1 is shown. In the example shown, the housing 1 is the housing of a door station. The door station is generally indicated by the reference numeral 2 and only some components of the door station 2 will be discussed here.

(6) The door station 2 has a number of buttons 3 for initiating communication with persons inside a building at which the door station 2 is used. Further, the door station has an outer opening section 4. As may be seen in FIG. 3, the outer opening 4 is part of an access passage 5, through which a microphone 6 inside the housing 1 of the door station 2 is accessible. Sound is hereby able to reach the microphone 6 from the outside of the door station 2.

(7) If the door station 2 is mounted outdoors, there is a risk that rain and snow will fall on it, and therefore a risk that water enters the outer opening 4. It may be noted that there is a risk of water entering the outer opening 4 even if the door station 2 is mounted indoors, e.g., if the housing is cleaned with a wet cloth or sponge. In the following, water entering the housing will be discussed, but the skilled person will realise that other liquids entering the housing may be equally relevant.

(8) Water and other liquids may be harmful to components inside the housing 1, and it is therefore important to avoid accumulation inside the housing 1. In order to ensure that water does not accumulate, the access passage 5 is provided with an inner drainage channel 7 extending downwards from the outer opening section 4 out through a bottom portion 8 of the housing 1. Furthermore, even if the amount of water entering the housing 1 is small, there is a risk that a water drop gets stuck in the outer opening section 4 unless the water drains away properly. If water stays in the outer opening section, it may block the access passage 5, such that sound from outside the door station cannot reach the microphone 6, thereby making communication difficult.

(9) As may be seen partially in FIG. 2, and more clearly in FIG. 3, the outer opening section 4 has vertical side walls 9, which extend from the outside of the housing 1 and into the housing 1. Only one such sidewall 9 is visible in the drawings, but in this embodiment, the access passage 5 is generally symmetrical, such that sidewalls 9 are formed inside both sides of the outer opening 4. The sidewalls 9 are tapered, such that they have a top width W.sub.T at a top of the outer opening section 4 which is narrower than a bottom width W.sub.B at a bottom of the outer opening section 4, i.e. closer to the drainage channel 7. The sidewalls 9 may be described as wedge-shaped portions of the wall around the outer opening 4.

(10) The sidewalls 9 provide a guiding surface for water and other liquids that enter the access passage 5. If a drop of water enters the outer opening section 4, surface tension and gravity will in combination with the shape of the sidewalls guide the water down towards the drainage channel 7. This makes it possible to avoid that water blocks the outer opening section 4. Thereby it is possible to ensure that sound from outside the door station 2 can reach the microphone 6. At the narrow top of the sidewalls 9, any water adhering in the outer opening 4 is likely to form a layer thin enough to easily break when acted on by a force, such as gravity. Further, as the sidewalls 9 are wider at the bottom, a thicker layer of water can form there, dragging any water adhering in the outer opening down and overcoming surface tension at the top of the sidewalls 9.

(11) Below the sidewalls 9 of the outer opening section 4, a guiding groove 10 is formed. The guiding groove 10 is intended to guide the water away from the side walls 9 towards the drainage channel 7. To enhance the guiding ability of the guiding groove 10, the guiding groove 10 has a cross section which is smaller than a cross section of the outer opening section 4. In this manner, surface tension and gravity will pull the water away from the outer opening section 4 towards the drainage channel 7.

(12) Similarly, to ensure that water is guided into the drainage channel 7 from the guiding groove 10, a cross section of the drainage channel 7 is smaller than the cross section of the guiding groove 10. The drainage channel 7 is rectangular or preferably square in cross section. Hereby, the risk that an air bubble blocks the entire cross section of the drainage channel is reduced. As air bubbles are round, and they thereby do not fill the entire rectangular cross section, liquid may still drain by means of the corners of the rectangular cross section, thus passing around the air bubble. This in turn improves the draining capability of the drainage channel 7.

(13) The microphone 6 is arranged above the outer opening section 4. Hereby, the microphone 6 may be well protected even in the event that an unexpectedly large volume of water enters the outer opening section, such that draining takes time and water temporarily accumulates in the access passage 5.

(14) Surfaces of the outer opening section 4, sidewalls 9, guiding groove 10, and drainage channel 7 are preferably made from a non-hydrophobic material. The use of non-hydrophobic material increases the tendency of water to enter the drainage channel and be drained out of the housing. Additionally, hydrophobic materials may be expensive and the configuration of the outer opening section 4, side walls 9, guiding groove 10, and drainage channel makes them unnecessary or even undesired.

(15) It will be appreciated that a person skilled in the art can modify the above described embodiments in many ways and still gain the benefits as shown in the embodiments above. As an example, in the embodiment shown, the outer opening section has a rectangular cross section, but it may instead be, e.g., circular. In such case, the shape of the sidewalls needs to be adapted to the cross-sectional shape of the outer opening section.

(16) Although the sidewalls are described as being vertical, the skilled person will realise that they need not be strictly vertical, but only vertical enough that drops of water will flow downwards along them.

(17) The housing may be formed without the guiding groove. The drainage channel will in such variants be arranged directly below the sidewalls of the outer opening section.

(18) In the example shown in the drawings, the drainage channel has a square cross section. It may have another rectangular cross section, or any other non-round cross section that would allow liquid to drain even in the presence of possible air bubbles. The cross section may, for instance, be polygonal, or be generally circular, but with a rectangular sub-portion along the length of the drainage channel for allowing liquid to drain unhindered by air bubbles.

(19) The description above has mainly been directed to a door station in which a microphone needs to be protected but accessible. In the door station, the microphone is protected from water and it is ensured that water does not block the access passage. The same solution may, however, be applied to other components and to other devices as well. For instance, the component may be another input device, such as a light sensor that needs to be accessible by light, a PIR detector that needs to be accessible by infrared radiation, or an image sensor that needs to be accessible by visible light or infrared radiation. Further, the component may be an output device, such as a light source that needs to be able to emit light outside the housing, or a sound-emitting component that needs to transmit sound outside the housing.

(20) The device may be any kind of device that has to be capable of being used or mounted in a position where it risks being subject to detrimental effects from, e.g., moisture, rain, snow, sunlight, or vandalism. The device may, for instance, be a monitoring camera, a speaker, a physical access controller, a card reader, a luminaire, or a traffic light.

(21) Several components may be arranged inside the same outer opening section. Further, the device may have two or more components, each being arranged inside a separate outer opening section.

(22) Thus, the teachings should not be limited to the shown embodiments but should only be defined by the appended claims.