Abstract
Airflow control device (1) for use in an air handling system, which comprises an outer tube (2) and at least one inner tube (3) arranged inside the outer tube (2). The inner tube (3) is at least partly made of flexible material and has an axial opening (4) through which air is adapted to flow. The inner tube (3) further exhibits an inlet part (8) and an outlet part (10), and a throttle part (9) between the inlet part and the outlet part. The device (1) is characterized by a pivotable throttling device (7) which is arranged to impact the inner tube (3), and thereby control the airflow through the inner tube (3), by rotation around a second pivot axis (b).
Claims
1. Airflow control device for use in an air handling system, which airflow control device comprises an outer tube, and further at least one inner tube arranged inside the outer tube, which inner tube at least partly is made of flexible material, the inner tube has an axial opening through which air is adapted to flow, and the inner tube further comprising an inlet part and an outlet part, and a throttle part between the inlet part and the outlet part, the airflow control device further comprising a pivotable throttling device which is arranged to impact the inner tube, and thereby control the airflow through the inner tube, by rotation around a pivot axis, which pivot axis is at least near perpendicular to a central axis of the inner tube; wherein the pivotable throttling device is a pivotable arc which is pivotally mounted in the outer tube, wherein the pivotable are is arranged inside the inner tube or between the outer tube and the inner tube.
2. The airflow control device according to claim 1, wherein the inlet part and the outlet part respectively exhibits an asymmetrical cone shape during throttling by the throttling device.
3. The airflow control device according to claim 1, wherein the throttling device is wire shaped.
4. The airflow control device according to claim 1, wherein the throttling device is made of steel sheet material.
5. The airflow control device according to claim 1, wherein the inner tube comprises a first end and a second end which are respectively attached at corresponding ends of the outer tube.
6. The airflow control device according to claim 1, wherein the throttling device is a pivotable ring which is pivotally mounted in the outer tube.
7. The airflow control device according to claim 1, wherein the length of the throttle part increases while the radial size of the axial opening decreases during throttling.
8. The airflow control device according to claim 1, wherein the throttling device is connected to a rotatable shaft, accessible from outside the outer tube.
9. The airflow control device according to claim 8, wherein the rotatable shaft is connected to an actuator, for controlling the airflow through the airflow control device.
10. The airflow control device according to claim 1, wherein the flexible material of the inner tube comprises fabric, textile, cloth, plastics or rubber.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1a-c shows a first embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in an open position.
(2) FIG. 2a-c shows a first embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a slightly throttled position.
(3) FIG. 3a-c shows a first embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a more throttled position than in FIG. 2a-c.
(4) FIG. 4a-c shows a first embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a nearly closed position.
(5) FIG. 5a-c shows a second embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in an open position.
(6) FIG. 6a-c shows a second embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a slightly throttled position.
(7) FIG. 7a-c shows a second embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a more throttled position than in FIG. 6a-c.
(8) FIG. 8a-c shows a second embodiment of the airflow control device 1 in a cross section, a perspective view and a section, when the device is in a nearly closed position.
(9) The constructive design by the present invention is obvious in the following description in detail of examples of embodiments of the invention related to the accompanying figures showing a first and second, but not limiting examples of embodiments of the invention. In addition the invention forwards the prior art in the field in different aspects. This is realized in the present invention by that the device of the below described art principally is constituted in a way that is obvious from the characterised part of claim 1.
DETAILED DESCRIPTION OF THE DRAWING
(10) FIG. 1a-c shows a preferred embodiment of the airflow control device 1 with an outer tube 2 and an inner tube 3 of flexible material arranged inside the outer tube 2. The tubes 2, 3 are aligned around a common first central axis a. In the preferred embodiment the inner tube 3 has a cross section slightly smaller than the outer tube 2, but smaller dimensions of the inner tube 3 is also possible. The airflow control device 1 is further arranged with a throttling device 7, which is arranged between the outer tube 2 and the flexible inner tube 3 and pivotable around a second pivot axis b. The second pivot axis b is perpendicular, or close to perpendicular in relation to the first device axis a. In other words, the second pivot axis b is arranged substantially perpendicular to an intended airflow direction through the device 1. By that the throttling device 7 is arranged between the outer tube 2 and the inner tube 3 it may press the inner tube 3 from its periphery and inwards when throttling, by a rotational motion around the second pivot axis b. Further, the throttling device 7 is thin not to impact the inner tube 3 more than necessary. In the preferred embodiment the throttling device 7 is designed as a pivotable ring 11, which is pivotally mounted in the outer tube 2. In this embodiment the ring 11 is not attached at the inner tube 3, but instead free to slide along the outer surface of the inner tube 3 during throttling/opening. The throttling device 7 may have any kind of wire-like design and consist of steel wire, rubber, plastic or similar, or for example consist of a thin steel sheet ring form. The throttling device 7, i.e. the ring 11 is in an open position, wherein an axial opening 4 of the inner tube 3 is fully open for airflow through the inner tube 3. The airflow direction is shown by arrows in FIG. 1c. It is preferred that a first end 5 and a second end 6 is respectively attached at the corresponding ends, or near the ends of the outer tube 2, and thereby at a distance from each other, preferably to form the shape of the inner tube 3. For example, the inner tube 3 may comprise stretchable material which is fixedly attached to one end of the outer tube 2 and then stretched and fixed to the other end to form the inner tube 3 in an appropriate way. Another option is that the inner tube 3 isn't stretchable, but anyway flexible, and thereby allowing the ring 11 to impact the material to throttle the inner tube 3. The inner tube 3 may also be a stand alone inner tube 3 which is insertable in the outer tube 2 as a self-carrying flexible tube inside the outer tube 2.
(11) As explained above is the ring 11 arranged between the outer tube 2 and the inner tube 3, but other alternatives are possible within the scope of the invention. For example, the ring 11 may be arranged inside a tight pocket or an elongated pocket, which is fitted on the inner tube 3. Another alternative may be a ring 11 arranged inside the inner tube 3. The latter option could for example be a stretched inner tube 3 of a small diameter, which then is widened by the ring 11 in the open position and then by the stretch and the smaller diameter will collapse during throttling.
(12) FIG. 2a-c shows the device 1 as described in FIG. 1a-c, where the throttle device 7, i.e. the ring 11 is in a slightly throttled position. In FIG. 2a the ring 11 is pivotally mounted in the outer tube 2 and also connected to a rotatable rod 13, which in turn is connected to an actuator 14. This is a simple solution for automatic regulation of the airflow, with known devices for motorization of the device 1. When throttling, the ring 11 directly comes in contact with the inner tube 3 from the open position and further slides along the inner tube 3, which is pushed from the outside and inwards and in a throttled position the inner tube 3 exhibits an inlet part 8, a throttle part 9, and an outlet part 10, as seen in FIG. 2b-c. It can also be seen that the inlet part 8 and the outlet part 10 exhibits an asymmetrical cone shape, which in tests proven positive for turbulence and noise characteristics. The good test results are also achieved by that the throttle part 9 mainly exhibits a form of a straight duct, which is more visible in FIG. 3c, below. Tests have also showed that increased throttling doesn't dramatically impair noise characteristics like in prior art solutions.
(13) FIG. 3a-c shows the device 1 as described in FIG. 1a-c, where the ring 11 is in a more throttled position than in FIG. 2a-c. It can still be seen that the inlet part 8 and the outlet part 10 exhibits an asymmetrical cone shape and also that the throttle part 9 mainly exhibits a form of a straight duct. Compared to FIG. 2c, it also can be seen that the length of the throttle part 9 is increasing the more the throttle device 7 is throttled, which means that less turbulence is achieved in the throttle part 9 as the flow passage is getting longer, which is positive for noise characteristics.
(14) FIG. 4a-c shows the device 1 as described in FIG. 1a-c, where the throttle device 7, i.e. the ring 11 is in a nearly closed position. It is fully possible to close the airflow control device 1 totally.
(15) FIG. 5a-c shows an alternative embodiment of the airflow control device 1 with a similar design as described above with reference to FIGS. 1-4. The difference is that the throttling device 7 is a pivotable arc 12, instead of a ring. The arc 12 is pivotable around the second pivot axis b in the same way as the ring. The function and the possible variants of how to arrange the pivotable arc 12 is applicable also with this variant in the same way as it is at the ring-type (outside, inside, pocket etc.). In the upright position, the airflow control device 1 is open for airflow through the axial opening 4 in the inner tube 3.
(16) FIG. 6a-c shows the device 1 as described in FIG. 5a-c, where the throttle device 7, i.e. the arc 12 is in a slightly throttled position. The arc-design gives another shape of the inner tube 3 compared to the ring-design. While the ring-design gives a similar but inverted inlet part 8 compared to outlet 10 part, with an elongated throttle part 9 in between, the arc 12 gives an inlet part 8 which differs from the outlet part 10, and the throttle part 9 is just the exact narrowest part, which is not elongated. The arc-design of the throttling device 7 gives a possibility to choose whether the pivoting motion of the arc 12 should be towards the air flow direction or along the same, which may be of importance for noise reduction. Still, the inlet part 8 as well as the outlet part 10 of the inner tube 3 exhibits an asymmetrical cone shape.
(17) FIG. 7a-c shows the device 1 as described in FIG. 5a-c, where the arc 12 is in a more throttled position than in FIG. 6a-c. Compared to FIG. 6c it can be seen that the throttling part is moved both in direction towards the airflow direction and also in a radial direction, which means that the inlet part 8 is getting shorter the more throttling of the airflow, while the outlet part 10 is getting longer.
(18) FIG. 8a-c shows the device 1 as described in FIG. 5a-c, where the throttle device 7, i.e. the arc 12 is in a nearly closed position. It is fully possible to close the airflow control device 1 totally.
PARTS LIST
(19) 1=airflow control device 2=outer tube 3=inner tube 4=axial opening 5=first end 6=second end 7=throttling device 8=inlet part 9=throttling part 10=outlet part 11=pivotable ring 12=pivotable arc 13=rotatable shaft 14=actuator
