DAMMING DEVICE FOR ERECTING A LIQUID-DAMMING PROTECTIVE BANK Technical Field of the Invention This invention relates to a damming device intended for forming a liquid-damming protective bank, which comprises components with the purpose of holding the device anchored against a surface, more precisely by friction action as a con- sequence of a vertically directed hydraulic pressure urging the device against the surface, as well as counteracting that liquid streams from a wet side or flood side to a dry side, means being provided between the surface and the actively act- ing protective bank for the purpose of draining away flood liquid which possibly leaks in under the device from the flood side so as to hold the surface on the bottom side of the device extending from the edge of the draining means being closest to the flood side to the dry the side at or close to atmospheric pressure with the purpose of achieving a maximum pressure dif- ference in relation to the hydraulic pressure holding the device urged against the surface.

Prior Art A damming device of the kind generally described above is previously known by SE 9500795-1. More precisely, this patent discloses a mobile device, the liquid-damming component of which is constituted by a flexible casing that may be expan- ded by being filled with water or air. An advantage of this device is that it may be stored in a collapsed state in which it occupies a minimum of space in conjunction with storing and transportation, and thereafter it may be expanded on location in a fast and simple way in areas where there is a risk for a flood. Furthermore, the device is easily and flexibly pliable, which means that the device may advantageously be used in order to dam water on soft and uneven surfaces, which may have infe- rior bearing capacity. In practice, the device also includes a relatively wide skirt connected to the flood side of the cas- ing, which skirt forms the anchoring component of the device.

By the fact that this skirt is wide, a reliable anchoring of the device is obtained. However, depending on the field of use,

the known damming device is also associated with certain disad- vantages. Thus, a disadvantage is that the flexible casing, made of plastic or rubber, runs the risk of being punctured at careless handling. Another disadvantage is that the casing occupies a considerable width besides the skirt. In case the casing would be given a large height with purpose of counter- acting floods having high water lines, the total width of the device would be considerable. For this reason the applicability of the device is in practice limited to relatively low water levels, for instance within the range of 0,5 - 1,5 m. At higher water levels, the device would require too large a total width in order to be able to be used successfully for instance inside densely built-up areas, in particular built-up areas with nar- row streets.

In addition to the above-mentioned damming device, also mechanical constructions of many different embodiments (see for instance US 898 984, US 4 136 995, US 4 692 060, US 4 921 373 and US 5 470 177) are used for flood control purposes.

These previously known mechanical flood control devices are based cn the fact that the power that the water or liquid pres- sure exert on them should, by support legs or other mechanical elements, be linked to the ground. However, this implies that the ground has a good bearing capacity. This is something which far from always is the case in the practical flood situation.

Theorecally, the mechanical damming devices may be erected to a high height, but this requires that the ground is strong and that the constructions are dimensioned very solidly. It can generally be said that the known, mechanical damming devices, at least theoretically, have a larger damming ability than the device known through SEE 9500795-1 that works with a flexibly, expandable casing. On the other hand, the last-mentioned device has a more reliable anchoring ability than the mechanical dam- ming devices.

Obiects and Features of the Invention The present invention aims at obviating the above- mentioned disadvantages and shortcomings of the above-related main categories of damming devices and at creating an improved damming device. Thus, a primary object of the invention is to

create a damming device that, for a given total width, is capa- ble of controlling high water levels. A further object is to create a device which does not run the risk of being punctured and thereby collapse in an active state. Still another object is to create a damming device which is robust in its active, liquid damming state, as well as constructionally simple and thereby cheap to manufacture. The device should furthermore be simple to transport and handle in conjunction with the erection of a protective bank.

According to the invention, at least the primary object is attained by the features defined in the characteriz- ing clause of claim 1. Preferred embodiments of the invention are furthermore defined in the dependent claims.

Brief Description of the Appended Drawinas In the drawings: Fig 1-3 are schematic cross-sections through three different main variants of the damming device according to the invention, Fig 4 is a perspective view showing the same damming device as in figure 1, although regarded from the dry side of the device, Fig 5 is a front view showing how a plurality of devices according to figure 4 are put together to a coherent protective bank situated on an uneven surface, Fig 6 is a perspective view showing a portion of the pro- tective bank according to figure 5 viewed from the flood side, Fig 7 is a perspective view of the same alternative embodi- ment of the device shown in figure 2, said device being viewed from the dry side, Fig 8 is a perspective view which shows, from the flood side, a portion of a protective bank composed of devices according to figure 7, Fig 9 is a cross section showing the same device as in fig- ure 3, more precisely in an active, liquid-damming state, Fig 10 is an analogous cross section showing the components of the device before the final assembly,

Fig 11 is a perspective view viewed from the flood side showing a protective bank composed of devices accord- ing to figures 9 and 10, and Fig 12 is a perspective view of an additional alternative embodiment of the invention.

Detailed Description of Preferred Embodiments of the Invention Figures 1-3 illustrate three different embodiments of the invention, which all have in common that they include a first, laying board 1 and a second up-right board 2. Of these boards, the first-mentioned one has the purpose of anchoring the device in its entirety, more precisely by being urged against the ground or another surface 4 by a liquid designated 3, in particular water, while the second board 2 has to the purpose of damming the liquid mass. Common for these three embodiments is furthermore that the laying board 1 on its bot- tom side has means 5 for draining away water which possibly leaks in under the board. The wet side or flood side of the damming device is generally designated 6, while the dry side is designated 7. The draining means 5 on the bottom side of board 1 may advantageously be in the form of a layer which extends along the entire width of the board, i.e. from the flood side to the dry side, although it is also conceivable to limit the width of the draining layer to only a part of the entire width of the anchoring board. In practice, the draining layer may be achieved in several different ways. The layer may, for instance, consist of a profiled, perforated or porous board which is either permanently attached to the bottom side of the anchoring board or loosely applied between the board and the ground. The layer may also consist of a plurality of laths, cross bars, legs or other spacing elements. In this connection it should also be mentioned that the draining layer or board may be made wedge-shapedly narrowing instead of being equally thick from a maximum height on the dry side to a minimal or unnoticeable height in the area of the wet side.

In all embodiments according to figures 1 to 3, a fabric or a similar flexible band element 8 which abuts against the ground 4 as well as against the top side of the anchoring board 1 is furthermore shown. This fabric may be in the form of

a separate unit which may be put over several anchoring boards following after each other or be applied on each individual board and have a larger length extension than the actual board in order to permit overlapping vis-a-vis an adjacent board.

A characteristic feature of all the embodiments of the invention is furthermore that devices act between the two boards 1, 2 with the purpose of inhibiting tilting of the up- right, liquid-damming board from the active position in the direction towards the dry side, when the liquid simultaneously acts on the anchoring board with a vertical force and the dam- ming board with a horizontal force.

In the following description the term "width" is used to describe the extension of the anchoring board between the edge of the flood side and the edge of the dry the side, while the term "length or "axial extension" is used to describe the extension of the anchoring board in a 900 angle to the width dimension. This terminology, however, does not limit the dimen- sions of the anchoring board. In practice therefore, the anchoring board may have a larger width than length.

Reference is now made to figures 4 to 6, which in combination with figure 1 illustrate a first, shovel-like embodiment of the damming device according to the invention. In this case, those devices that have the purpose of holding the damming board 2 in an upright position, consist of two tensile force carrying connection devices which extend between the wet side of the damming board and the anchoring board 1. More pre- cisely, these connection devices consist of end surfaces 9, 9' which extend along the two opposite, transversal edges of the board 1 and the two opposite, up-right edges of the damming board 2. The boards 1, 2 are interconnected in a liquid-proof way along the connection line 10 which extends along the lower edge of the damming board and the top side of the anchoring board. A liquid-proof connection also exists along the lines 11, 12 which connect the individual end surface to the damming board 2 and the anchoring board 1, respectively. In practice the boards 1 and 2 as well as the end surfaces 9, 9' may be made of plates which are united to each other by means of weld- ing. In this context, however, it should be pointed out that the end surfaces 9, 9' also may be made of an elastically

flexible material. However, in practice it is preferred to make the individual end surface of a shape-stiff material like the damming and anchoring boards and to stiffly unite the end sur- face with these boards while forming a construction which is shovel-like and which, in an active state, opens towards the flood side.

For forming a continuous protective bank of the type shown in figures 5 and 6, a plurality of such, shovel-like dam- ming devices are placed side-by-side adjacent to each other. In order to achieve sealing of adjacent damming devices in the assembled protective bank, advantageously cross-section-wisely substantially U-shaped sealing strips 13 (or bands) are arran- ged, which are applied on the free edges of adjacent end sur- faces in order to bridge possible spaces therebetween.

In order to facilitate erection of damming devices on uneven grounds of the type which is indicated in figure 5, the damming board 2 may in a flat, tension-free state have oblique edges which mutually diverge in the direction upwards. By the connection thereof to the end surfaces 9, these edges also keep the end surfaces in a state diverging from each other in the direction upwards, which allows several damming devices to be tiled in each other. A loading or tightening mechanism gene- rally designated 14 extends between the side edges of the dam- ming board 2 which has the purpose of, when required, reducing the distance between the upper parts of the side edges and thereby those of the end surfaces, more precisely by bringing the damming board 2 to sag in the direction towards the flood side, as is apparent from figure 4. Suppose that the angle bet- ween the individual end surface and the appurtenant anchoring board should be variable within the range of 88 - 920 in order to enable obliquity of the anchoring board of an adjacent device within the range of +20 to -20 relative to the horizon- tal plane. In this case the device may be made with end sur- faces, each one of which having an angle of, for instance, 93" relative to the anchoring board. When such a prefabricated device has been put in place, the desired angle of inclination may be achieved by reducing the length of the loading mechanism 14, the damming board 2 in the area of the upper edge thereof sagging in the direction inwards towards the flood side. This

not only leads to the advantage that the bottom of the ready- made protective bank may be adjusted to uneven ground but also that the damming board receives a better geometry force carry- ing-wise than if it were plane.

In other respects, it may be mentioned that the end surfaces 9, 9' in the shown embodiment have been formed with an upper edge 15 which is horizontal as well as an edge 16 leaning downwardly therefrom which ends at a distance from the rear edge 10' of the board 1. By the fact that the end surfaces are, in this manner, terminated at a certain distance from the edge 10', room is given for the above-mentioned sealing fabric or band 8, whereby this band may simultaneously cover several sealing devices subsequently following each other in the ready- made protective bank. In order to decrease the effect of possi- ble waves and/or streams in the dammed water mass, the devices should, when required, be able to be provided with particular boards (not shown) which rest against or are connected to the leaning edge portions of the end surfaces 9, 9'. Such an addi- tional board may be made either with the same axial extension as the individual damming device or be longer so as to cover several devices positioned adjacent to each other. However, the additional boards have to allow water to pass into and out of the space between the end surfaces, preferably through a gap between the lower edge of the additional board and the anchor- ing board 1.

In case a protective bank needs to be erected with angles between different sections, particular damming devices may be used, the bottom boards of which having non-parallel cross edges 12. With four perpendicular corner devices and a number of standard devices even a temporary pool may be created on the desired surface.

Reference is now made to figures 7 and 8 which in combination with figure 2 show a second, alternative embodiment of the invention. In this case, the devices which have the pur- pose of holding the damming board 1 in place in an upright position consist of one or more compressive force carrying sup- port devices 17 arranged to act between the dry side of the damming board 2 and a portion 1' protruding from the damming board of the anchoring board 1. In practice, these support

devices may advantageously consist of up-right boards which in an active state protrude at an angle, for instance a perpen- dicular angle, from the dry side of the damming boards 2 and upwards from the top side of the protruding board portion 1'.

Although the support boards 17 may be firmly connected to at least one of the boards 1, 2, they may also be flexibly con- nected to one of the boards, for instance via hinges which per- mit folding of the boards, for instance towards the dry side of the damming board in order to reduce the space of the support boards in conjunction with storage and transportation. Instead of boards, thin legs or bars which carry compressive force in the area between the dry side of the damming board and the board portion 1' may also be used.

As may be seen in figure 8, the spaces or openings which arise between adjacent damming devices in a continuous protective bank may be sealed by means of a separate sealing member 18, for instance a strip or fabric, an angled plate or the like. By the fact that the sealing member partly has an air gap on the bottom side thereof it will be held urged in the desired position by the water pressure acting from above. The member is made sufficiently stiff so as to be able to bridge also wider openings. In case the member is made of a stiff material, it may advantageously have sealing fillets along its long sides or foam rubber on its bottom side. As an additional security, in particular at low water levels, the sealing member may also be fixed in a mechanical way, for instance be clamped by a resilient holder, be fitted below hooks, etc.

In figure 8 the joint being furthest to the left is shown between adjacent damming devices situated above a hallow in the ground, while the next opening is above a ridge. The opening between adjacent anchoring boards is in both cases equally wide, but the opening between the damming boards will in one of the cases diverge and in the other case converge. The three damming devices shown furthest to the right in figure 8 stand on plane ground, but are angled in relation to each other in the ground plane, the two joints between the damming boards narrowing wedge-shapedly in opposite directions. Thus, the width of the openings between anchoring boards varies here,

while the openings between adjacent damming boards become par- allel.

Reference is now made to figures 9-11 which in combi- nation with figure 3 show a third embodiment of the damming device according the invention. In this case, the tensile force carrying connection device between the boards 1, 2 consists of a long narrow element 19 which at one end is attached to the wet side of the damming board, more precisely at a distance from the lower edge of this board, and at an opposite end is attached to the anchoring board, more precisely at a distance from the damming board. In practice, the connection element 19 may consist of a wire, rod or the like, which is coupled to suitable fastenings. In this embodiment, the boards 1, 2 con- situate separate components which may be interconnected when the need arises, i.e. when a protective bank is to be erected and the two boards are to fulfil their purposes. Although con- nection of the two boards may be realised in many different ways, figures 9 and 10 show how the anchoring board 1 in the area of its dry side has a groove 20 in which the lower edge 21 of the damming board 2 may be applied. In other words, the lower edge 21 of the damming board forms a male-like element and the groove 20 a seat for this male element. A continuous, liquid-proof fabric 22 is applied against and fixed to the inside of the damming board 2 and the top side of the anchoring board 1, a flexible portion of the fabric extending between the separated boards. When the boards are mounted together, this fabric folds in the transition between the boards without loos- ing its liquid-sealing ability.

As may be seen in figure 11, the fabric 22 may advan- tageously be common for adjacent damming devices in the form of boards 1, 2 co-acting in pairs. Thus, in the boundary zone bet- ween two adjacent damming devices, a flexible fabric portion 22' will extend admitting a certain mobility between the dif- ferent boards. Along the long side edge of the ready-made erected protective bank, which is directed towards the flood side, the fabric 22 has a larger width than the anchoring boards 1, a projecting portion of the fabric sealing against water leakage under the anchoring board.

In figure 12 an additional embodiment is shown accor- ding to which a number of tensile force carrying connection devices between the damming board 2 and the anchoring board 1 consist of beads generally designated 23. Each such bead 23 is formed as a continuous and cross-section-wise arched member composed of a board portion 24 outwardly cambered inwards from the damming board 2 as well as a board portion 25 outwardly cambered upwards from the anchoring board 1. In practice, the arched board portion 24 may extend along the major part of the height of the damming board 2 (or even the entire height) at the same time as the corresponding board portion 25 of anchor- ing board 1 extends along the major part of the width thereof.

The board portion 24 narrows in the direction towards the upper end 24' thereof. In an analogous way, the board portion 25 nar- rows in the direction towards an end portion 25' which is dis- tanced from the damming board 2. The narrowing shape of each board portion respectively is made along the side extension as well the down extension. By the fact that the vertical and horizontal board portions of the bead narrow, several damming devices may be tiled in each other.

In the example according to figure 12, the damming device includes four mutually parallel beads 23. The free ends of the board portions 25 which are included in said beads mouth in a common collection channel 26 which is delimited by a board portion designated 27 which extends axially between the two opposite side edges of the anchoring board 1. Most suitably the channel 26 extends parallel to the damming board 2. Adjacent to the channel-limiting board portion 27 a fabric or skirt 28 is arranged which, as previously described, forms a sealing against the ground. In case water would leak in under the skirt 28 and the rear, plane portion of the board 1, the water will be distributed via the channel 26 to one or more of the chan- nels which are defined by the arched beads and drained out on the dry side of the damming device. In other words, the arched beads 23 constitute not only tensile force carrying connection devices between the two boards 1 and 2, but also a draining means.

Feasible Modifications of the Invention The invention is not solely restricted to the embodi- ments described above and shown in the drawings. Thus, only one, suitably centrally located, stiff or flexible device hav- ing a large surface extension may be used as tensile force car- rying device instead of two (stiff or flexible) end surfaces at opposite cross edges. Furthermore, it is conceivable to make the shovel-like embodiment according to figures 4-6 in such a way that the boards and end surfaces respectively may be folded in relation to each other so as to facilitate storing and transportation.