POOL COVER MECHANISM

Abstract

The invention relates to a pool cover mechanism for winding and unwinding slats over a pool. The pool cover mechanism comprises a tube for connecting with the slats, a tube motor assembly for rotating the tube, a first holder for receiving the non-rotating motor end of the tube motor assembly, an outer shaft bearing assembly connected to the second end of the tube, a second holder for receiving the outer shaft bearing assembly, wherein the outer shaft bearing assembly and the second holder are configured such that at least part of the outer shaft bearing assembly can rotate in the second holder when the tube is tilted compared to the position of the tube wherein the motor end is in the first holder.

Description

TECHNICAL FIELD

The present invention relates to a pool cover and more particular to a pool cover mechanism for winding and unwinding slats over a swimming pool.

BACKGROUND ART

Pool cover systems are known. There are pool cover systems wherein the mechanism for winding and unwinding the pool cover is positioned outside the water, and there are pool cover systems wherein the mechanism for winding and unwinding the pool cover are positioned underwater. The latter known underwater pool cover mechanisms use a stainless-steel tube inside the swimming pool as base for winding and unwinding the slats which cover the swimming pool when unwound.

The function of the cover is to cover the swimming pool when it is not in use. It protects the water from evaporation and loss of water as well as insulation to limit heat loss from the water. Another function of the cover is to avoid accidental access to the swimming pool for people, especially young children which could lead to drowning or other injury.

There are several types of cover systems. Most common type is a cover system where a roll of slats is mounted inside the swimming pool under the water level. The activation of the cover system is done by a motor which can be installed outside or inside the swimming pool. The motor is connected to and rotates a cylindrical-shaped element. For easy reading the cylindrical-shaped element is in the present application called “tube”.

The tube needs to rotate. Therefore, a bearing or support system is provided on both ends of the tube, called the motor side and the opposite motor side or the bearing side.

A know mechanism to rotate the tube is a mechanism with a tube motor. This simplifies the mechanism to drive the pool cover. The tube motor is positioned inside the tube and is sealed and protected against water infiltration, and a motor shaft is extending outside the tube. When installed, the motor shaft is supported in a fixed position in a holder which is firmly fixed or attached to the side walls of the swimming pool. When the motor is rotating, an outer arrangement of the motor is rotating around the fixed motor shaft and because the tube is connected with the outer arrangement, the tube is rotating around the fixed motor axis.

The motor can rotate in two directions causing the tube to rotate in two directions. When the slats are connected to the tube, the rotation of the motor unwinds and winds the slats respectively off and on the tube. The size and power of the motor can be adapted according to the needs of the system. A known cover drive system uses for example a tube motor powered by 24V DC.

A power cable is connected to the motor at the side of the motor shaft. The power cable is guided from the inside of the swimming pool to the outside. Outside the swimming pool the cable is connected to a connection box which on its turn is connected by another cable to a pool cover controller.

There are several known methods to bring one end of the power cable outside the swimming pool while avoiding any contact between the slats and the cable during rotation of the cover mechanism. Any contact may damage the motor cable. In one known arrangement a cable duct is provided which is mounted against the side walls of the swimming pool. In another known arrangement a wall duct is provided which is installed inside the wall of the swimming pool, connects the inside with the outside of the swimming pool and guides the motor cable.

The power of the chosen motor is dependent on the size of the cover corresponding to the size of the swimming pool and the size of the slats. The motor must be able to overcome the buoyancy or force from the water on the air-filled slats, especially during the opening of the cover.

The slats are connected the tube. A known arrangement to connect the slats to the tube is by using straps. The straps are fixed at one end to the tube and at the other end to the first slat. The fixation of the straps on the tube is done by using screws and plugs. A number of straps are evenly spaced along the length of the tube. The fixation of the straps to the first slat is done by making slots or holes in the first slat and to loop the strap through the slot of hole in the first slat. This known method of connecting the first slat to the tube has a number of problems. The installer need to be cautious when making the slotted holes in the first slat to make sure that it will be aligned with the fixation point of the strap at the other end to the tube. If the slotted holes are not aligned with the fixation points on the tube, then the straps will be wound under an angle when the cover is opened. Further, not aligned fixation might also result in uneven tension between the different straps when pulling on the slats before winding the slats on the tube.

Known pool cover mechanisms use tubes which are made of stainless steel. The stainless-steel tube must be of the specific grade 316L, because the tube is permanently installed in the swimming pool wherein the water may be treated with chlorination. A problem however when using stainless steel tubes is that these tubes are very heavy and difficult to carry and handle. Such tubes require at least 2 persons for the installation. Also, the installation of a cover mechanism with a stainless-steel tube is rather complex and requires multiple parts such as metal parts, sealings and different kinds of fixations in order to fix the tube to the side walls of the swimming pool.

Another problem of the stainless-steel tubes is that such tubes need to have a length corresponding to the width of the swimming pool. Most common widths of swimming pools are between 4 m and 6 m. This causes the need for special transport to transport the stainless-steel tube from the manufacturer to the customer. Furthermore, the length of the stainless-steel tube is dependent on the final width of the swimming pool, causing that the stainless-steel tube can only be ordered when the final width of the swimming pool is known. This in combination with the fact that the lead time is rather long causes another problem for the installer. On top of that may the width of the swimming pool be varying over the height of the swimming pool causing that measuring the correct width of the swimming pool at the installation height of the tube is cumbersome for the installer which may results in mistakes. And, if a mistake is made then the ordered tube might be too short or will not fit within the width of the swimming pool, which might result in losses for the installer and delays of the installation.

Further, the supports for holding the tube must be very well aligned and accurately positioned on the pool walls. As the pool walls are not always perfectly parallel, it's time consuming for the installer to make the proper alignment. And, to position the supports accurately, corresponding mounting holes must be made to make sure that both centres of the supports are aligned. Improper installation or misalignment may result in excessive wear of several components including motor, slats, guides, bearing surfaces etc.

Other known pool cover mechanisms use tubes outside the swimming pool to wind and unwind the cover.

The installation of the pool cover mechanism is often one of the toughest tasks for the installer. The cover is one of the last items which needs to be installed before filling the pool with water. However, certain installation requirements must be taken into account from the very beginning of the pool construction. From an installer perspective, a lot of time is spent on the installation of the pool cover mechanism because of the complexity and because of the strict requirements for alignment and positioning for smooth operation.

Next to the installation, the pool cover mechanism may also need maintenance or repairing. In known pool cover mechanism, maintenance or repairing of the tube motor is possible but it is very cumbersome. The installed tube must be disassembled from the supports to be able to access the tube motor and drainage of swimming pool is mostly needed.

DISCLOSURE OF THE INVENTION

It is an aim of the present invention to provide a pool cover mechanism which overcomes at least some of the above mentioned problems.

This aim is achieved according to the invention with a pool cover mechanism for winding and unwinding slats over a pool, the pool cover mechanism comprising a tube for connecting with the slats, a tube motor assembly for rotating the tube wherein the tube motor assembly is connected to the tube at a first end and wherein the tube motor assembly comprises a tube motor and a non-rotating motor end when the tube motor is rotating, a first holder for receiving the non-rotating motor end of the tube motor assembly, an outer shaft bearing assembly connected to the second end of the tube wherein the outer shaft bearing assembly is configured to allow rotation of the tube when the tube motor is rotating, a second holder for receiving the outer shaft bearing assembly, wherein the outer shaft bearing assembly and the second holder are configured such that at least part of the outer shaft bearing end can rotate in the second holder when the tube is tilted compared to the position of the tube wherein the motor end is in the first holder and wherein the outer shaft bearing assembly comprises a first group of elements and a second group of elements, wherein the first group of elements and the second group of elements are configured such that the first group of elements can do a sliding movement relative to the second group of elements in the axial direction of the tube.

This pool cover mechanism provides multiple advantages. The installer can position one end of the tube in the holder and can subsequently rotate the other side of the tube to the other holder while the first end remains in the first holder. Further, when maintenance or repair is needed, the installer can remove one end of the tube from the holder, tilt the tube while the other end is rotating in the holder such that the tube motor is accessible without removing the tube from the other holder. This arrangement has also the advantage that when the outer shaft bearing assembly is received in the second holder, the tube can be moved in axial direction of the tube relative to the second holder. This allow to position at the opposite side the tube motor assembly on the exact position in the first holder. Furthermore, the relative sliding movement functionality combined with the tilting functionality have together the advantage that the tube motor can be tilted above the water level of the pool and slid over the side wall of the pool for easy access.

In an embodiment of the invention, the outer shaft bearing assembly comprises a ball joint and a ball joint housing, wherein the ball joint can rotate in the ball joint housing when the ball joint housing is received in the second holder and the tube is tilted compared to the position of the tube wherein the motor end is in the first holder.

This arrangement with a ball joint and a ball joint housing has the advantage that the outer shaft bearing assembly can be easily mounted in the second holder and that the ball joint has rotational freedom inside the ball joint holder and thus also in the second holder.

In an embodiment of the invention, the outer shaft bearing assembly comprises an outer shaft bearing connected to the second end of the tube. The outer shaft bearing connected to the outer shaft has the advantage that the outer shaft bearing assembly is supporting the tube very well.

In an embodiment of the invention, the outer shaft bearing has a central opening, the ball joint has a shaft portion, and the central opening and the ball joint are configured such that the outer shaft bearing can slide in the axial direction over the shaft portion.

This arrangement where the outer shaft bearing, and thus also the tube connected to the outer shaft bearing and the tube motor assembly, can slide together over the shaft portion of the ball joint, has the advantage that easy installation by a single person is possible. This arrangement also allows to have some deviations on the tube length compared to the calculated optimal length dependent on the exact width of the swimming pool. Further, by having the combination of the freedom of rotation by the ball joint and the sliding outer shaft bearing over the shaft portion of the ball joint, the tube motor assembly can be tilted up to the edge of the pool above the water level, allowing easy disassembly and assembly of a replacement tube motor.

In an embodiment of the invention, the outer bearing assembly further comprises a stopper and the stopper is configured such that the stopper limits the sliding of the outer shaft bearing over the shaft portion. The stopper ensures that that the outer bearing remains on the shaft portions.

In an embodiment of the invention, the tube is a single tube.

A mechanism with a single tube can be advantageous in specific situation.

In an embodiment of the invention, the tube comprises at least two outer tubes and at least one inner tube, wherein the inner tube is configured to have an outer profile which corresponds to the inner profile of the outer tube such that the inner tube can slide into the outer tubes and such that the inner tube is rotating when the outer tube is rotating.

The arrangement with at least two outer tubes and one inner tube has the advantage that the length of the tube can be adjusted by sliding the inner tube deeper or less deep in the outer tube.

In an embodiment of the invention, the first holder is identical to the second holder.

This is advantage during installation and manufacturing as less different parts are needed.

In an embodiment of the invention, the first holder and the second holder are not identical.

This arrangement may be advantageous in specific situations.

In an embodiment of the invention, the outer shaft bearing assembly and the second holder are configured such that the at least part of the outer shaft bearing assembly can rotate in the second holder between 0 and 20° when the tube is tilted between 0 and 20° compared to the position of the tube wherein the motor end is in the first holder.

This has the advantage that the tube can be tilted high enough to bring the tube motor above the water level.

In an alternative embodiment of the invention, the aim is achieved according to the invention with a pool cover mechanism for winding and unwinding slats over a pool, the pool cover mechanism comprising a tube for connecting with the slats, a tube motor assembly for rotating the tube wherein the tube motor assembly is connected to the tube at a first end and wherein the tube motor assembly comprises a tube motor and a non-rotating motor end when the tube motor is rotating, a first holder for receiving the non-rotating motor end of the tube motor assembly, an outer shaft bearing assembly connected to the second end of the tube wherein the outer shaft bearing assembly is configured to allow rotation of the tube when the tube motor is rotating, a second holder for receiving the outer shaft bearing assembly, characterized in that the tube comprises at least two outer tubes and at least one inner tube, wherein the inner tube is configured to have an outer profile which corresponds to the inner profile of the outer tube such that the inner tube can slide into the outer tubes and such that the inner tube is rotating when the outer tube is rotating.

This pool cover mechanism has the advantage that one set of two outer tubes and one inner tube can be used for a range of widths of the swimming pool. The same tube can be installed at different heights even if the width of the swimming pool is changing over the height of the pool wall. This pool cover mechanism makes the installation of the tube much easier. In an embodiment of the invention, the outer tube has a cylindrical shaped outer profile.

This is advantageous because the slats of the cover are wound on the outer surface of the outer tube such that any protruding elements will have a negative impact on the winding of the slats and might deform or damage the slats.

In an embodiment of the invention, the inner profile of the outer tube comprises at least one recess area and the outer profile of the inner tube comprises at least one protrusion.

This arrangements enables proper engagement with allows power transmission between the outer and inner tube.

In an embodiment of the invention, the at least two outer tubes are fixed with respect to the at least one inner tube such that the at least two outer tubes and the at least one inner tube fixed towards each other have a fixed length.

This arrangement has the advantage that when the desired length of the tube is known during installation, the length of the two outer tubes and the inner tube can be adjusted and fixed. This makes installation more easy.

In an embodiment of the invention, the at least two outer tubes are fixed to the at least one inner tube by at least one screw positioned in the at least one protrusion.

This arrangement has the advantage that it is easy to execute.

In an embodiment of the invention, the inner profile of the outer tube and the outer profile of the inner tube are configured such that there is a minimal clearance between the inner profile of the outer tube and the outer profile of the inner tube.

The clearance has the advantage that backlash is avoided.

In an embodiment of the invention, the inner profile comprises three recessed areas and the outer profile comprises three protrusions.

This arrangement has the advantage that forces can be spread over the circumference of the profiles.

In an embodiment of the invention, the tube further comprises a strap link assembled on the inner tube, wherein the strap link has an outer profile with a cylindrical shape and with a diameter corresponding to the diameter of the outer cylindrical surface of the outer tube.

This arrangement has the advantage that a strap can be connected to the inner profile in the same way as a strap is connected to the outer profile such that the same forces are applied on the first slat.

In an further alternative embodiment of the invention, the aim is achieved according to the invention with a pool cover mechanism for winding and unwinding a number of connected slats over a pool, the pool cover mechanism comprising a tube for connecting with the slats, a tube motor assembly for rotating the tube wherein the tube motor assembly is connected to the tube at a first end and wherein the tube motor assembly comprises a tube motor and a non-rotating motor end when the tube motor is rotating, a first holder for receiving the non-rotating motor end of the tube motor assembly, an outer shaft bearing assembly connected to the second end of the tube wherein the outer shaft bearing assembly is configured to allow rotation of the tube when the tube motor is rotating, a second holder for receiving the outer shaft bearing assembly, and at least one strap connected to the tube, characterized in that the pool cover mechanism further comprises at least one slat connector for connecting the at least one strap to the first slat of the number of connected slats, wherein the at least one slat connector comprises a buckle having two leg portions and being configured to connect with the strap and a C-shaped tube having a slit over the whole length of the C-shaped tube for sliding over a part of the slat and having a slot in the C-shaped tube opposite to the slit for receiving the buckle, wherein the slot is configured such that the two leg portions of the buckle are anchored inside the C-shaped tube when the buckle is connected to the strap.

This pool cover mechanism has the advantage that no slots or holes has to be made in the first slat to connect the slats with the tube. The C-shaped slat connector fits to all kind of slats by simply sliding the slat connector over the first slat.

In an embodiment of the invention, the strap comprises a loop and the buckle is connected with the loop by arranging a part of the buckle in the loop while the legs of the buckle are arranged in the C-shaped tube.

This arrangement has the advantage that the strap can be connected to the slat without making any holes or slots in the slat and without the need to use extra fixation elements.

In an embodiment of the invention, the slit is narrower at the ends of the C-shaped tube compared to the middle of the C-shaped tube.

This arrangement allows to have a width at the sides which is optimized to slide over the slats and to have at the same time a width in the middle to assemble the strap and the buckle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a pool cover mechanism according to an embodiment of the present invention.

FIG. 1B illustrates a tube assembly according to an embodiment of the present invention.

FIG. 1C illustrates a tube motor and a corresponding holder according to an embodiment of the present invention.

FIG. 1D illustrates an outer shaft bearing assembly according to an embodiment of the present invention.

FIG. 2A illustrates a cross section of an inner tube according to an embodiment of the present invention.

FIG. 2B illustrates a cross section of an outer tube according to an embodiment of the present invention.

FIG. 3 illustrates an outer tube according to an embodiment of the present invention including three cross sections at positions where holes are foreseen in the outer tube.

FIG. 4A illustrates a pool cover mechanism according to an embodiment of the present invention installed in a pool wherein only two walls of the pool are visible to allow a view on the mechanism, and a detailed view of the outer shaft bearing assembly in a holder assembled to the wall of the pool.

FIG. 4B illustrates a pool cover mechanism according to an embodiment of the present invention installed in a pool wherein only two walls of the pool are visible to allow a view on the mechanism.

FIGS. 5A and 5B illustrate a pool cover mechanism according to an embodiment of the present invention in an operational position and in a maintenance position.

FIGS. 6A and 6B illustrate a tube assembly according to an embodiment of the present invention in a perspective view.

FIG. 6C illustrates the tube assembly of FIGS. 6A and 6B assembled including a zoom window and a cross section.

FIG. 6D illustrates the connection of a tube motor assembly in a tube according to an embodiment of the present invention.

FIG. 7A illustrates a tube motor assembly according to an embodiment of the present invention.

FIG. 7B is cross section through the front flange of the tube motor assembly of FIG. 7A.

FIG. 7C is a view on the rear flange of the tube motor assembly of FIG. 7A.

FIGS. 8A and 8B illustrate the outer shaft bearing assembly, respectively assembled and in exploded view.

FIGS. 9A to 9D illustrate the steps for installing the outer shaft bearing assembly in a holder fixed to a side wall of a swimming pool according to an embodiment of the present invention.

FIGS. 10A to 10D illustrate the steps for installing the tube motor assembly in holder which is fixed to a side wall of a swimming pool according to an embodiment of the present invention.

FIG. 11 illustrates how a strap is connected to a first slat according to an embodiment of the present invention.

FIGS. 12A to 12D shows step by step the connection of the strap to the first slat according to an embodiment of the present invention.

FIG. 13 shows a perspective view of a buckle to connect a strap to a first slat according to an embodiment of the present invention.

FIG. 14 shows a perspective view of the slat connector according to an embodiment of the present invention.

MODES FOR CARRYING OUT THE INVENTION

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

Furthermore, the various embodiments, although referred to as “preferred” are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.

The term “comprising”, used in the claims, should not be interpreted as being restricted to the elements or steps listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising A and B” should not be limited to devices consisting only of components A and B, rather with respect to the present invention, the only enumerated components of the device are A and B, and further the claim should be interpreted as including equivalents of those components.

FIG. 1A illustrates a pool cover system according to an embodiment of the present invention. The pool cover system has a tube 48, a tube motor assembly 47, an outer shaft bearing assembly 51, straps 52, slats 55, buckles 54, slat connectors 53 and two holders 46.

As illustrated in FIG. 1B, the tube 48 has in the embodiment of FIG. 1A two 2 outer tubes 1 and 1 inner tube 2. In an alternative embodiment the tube 48 can be a single tube. Or, in still another embodiment the tube 48 can have more than two outer tubes 1 and more than one inner tubes 2. The tube 48 can be made at a length corresponding to the width of a swimming pool. In embodiments with more than one outer tube 1 or more than one inner tube 2, the length of each outer tube 1 and each inner tube 2 can be different.

In the embodiment of FIG. 1A, the two outer tubes 1 and the inner tube 2 are assembled together to meet the required length to be mounted in a swimming pool. The length of the tube 48 can be adjusted to correspond to the width needed for the swimming pool. With a single tube set of two outer tubes 1 and an inner tube 2 a range of lengths can be covered depending on the length of the outer tubes 1 and the length of the inner tube 2. In this embodiment, the minimum length of the tube 48 is determined by the length of the two outer tubes 1 at a position wherein both outer tubes 1 are adjacent to each other and wherein the inner tube 2 is completely covered by both outer tubes 1. In this assembling position, half of the inner tube 2 is preferably covered by the first outer tube 1 and the other half of the inner tube 2 is preferably covered by the second outer tube 1. Still in the embodiment of FIG. 1A, the maximum length of the tube 48 is determined by the length of both outer tubes 1 and the exposed length of the inner tube 2. The maximum length is two times the length of the outer tube 1 plus the length of the inner tube 2 minus the minimum inserted portion of the inner tube 2 inside the outer tubes 1. In a preferred embodiment of the present invention, the minimum inserted portion of the inner tube 2 is at each side approximately 20 cm. Between the minimum length and the maximum length of the tube 48, all tube lengths are possible. This structure of the tube 48 provides a lot of advantages. The installer does not need to wait until the swimming pool is finished to order the tube 48 because an indication of the required length of the tube is sufficient to order. Once the pool is finished, the tube 48 can be adjusted to the needed length by sliding the outer tubes 1 over the inner tube 2 until the desired length is reached and by fixing subsequently the outer tubes 1 with the inner tube 2 at this desired length. Small deviations of the width of the swimming pool compared to the technical drawings of the project have no longer an impact on the installation or timing. For embodiments wherein the tube 48 is installed underwater, the outer tube 1 and the inner tube 2 are preferably made of stainless steel 316L or glass fibre reinforced vinyl ester. In alternative embodiments, other materials may be used.

As illustrated in FIG. 1B, the outer tubes 1 and inner tube 2 are fixed together in axial direction by means of screws 7 and plugs 6. In an alternative embodiment of the present invention, fixation of the outer tubes 1 and the inner tube 2 can be performed by means of bolts, bolts and screws in combination with hollow wall anchors, split pens or any other fixation means which does not protrude outside the outer cylindrical surface 25 of the outer tube 1.

The cylindrical surface 25 of the outer tube 1 should remain free from any protruding elements because the slats 55 of the cover are wound on this outer surface 25. Any protruding elements will have a negative impact on the winding of the slats 55 and might deform or damage the slats 55. For this reason, the pre-drilled holes in the outer tubes 1 to fix the outer tube 1 with the inner tube 2 are countersunk holes in which the head of the fixation element is recessed.

The outer tubes 1 have holes 39 (shown in Section B-B in FIG. 3), which are used to connect an end of the straps 52 to the outer tubes 1. The straps 52 are at the other end connected to the slats 55. In an embodiment of the present invention, the straps 52 can have one or more holes to insert a plug 5 to fix a strap 52 to an outer tube 1. In an alternative embodiment, a different method can be applied to fix a strap 52 to an outer tubes 1. Each outer tube 1 has several holes 39 for connecting straps 52. Preferably the holes 39 are equally spaced over the length of an outer tube 1. Depending on the actual adjusted length of the tube 48 more or less holes 39 of the outer tubes 1 can be used.

In an embodiment of the present invention, in case the tube 48 is not set to the minimum length, a strap link 3 is provided as illustrated on FIGS. 1B and 1A. The strap link 3 is slid over the inner tube 2 and has the same profile as the outer tube 1. Preferably the strap link 3 is positioned and fixed in the middle of the inner tube 2 and allows the fixation of a strap 52 in the middle of the tube 48. The strap link 3 may also have a pre-drilled hole for fixing the strap 52, similar as the holes 39 in the outer tube 1. The width of the strap link 3 must be at least equal to the width of a strap 52. In another embodiment, the width of the strap link 3 is larger than the width of a strap 52 in order to be more tolerant towards misalignments between the location of the strap connection 53 with the slats 55 and the location of the strap link 3 on the inner tube 2. The strap link 3 may be fixed by means of screws 4 to the inner tube 2. In an embodiment, the strap link 3 is connected to the inner tube 2 such that the hole in the strap link 3 for fixing a strap 52 is aligned in axial direction with the holes 39 in the outer tubes 1 for fixing the straps 52. This alignment of the holes has the advantage that straps 52, which have the same length, also have the same amount of tension when pulling the slats 55.

FIGS. 1A and 1C, and FIGS. 7A and 6D illustrate the tube motor assembly 47. The tube motor assembly comprises a tube motor 15, a front motor flange 30, a rear motor flange 31, a motor shaft 27, a backlash rubber 13 and a motor pin 14. The tube motor 15 is inserted in one of the outer tubes 1. The tube motor 15 is fixed in axial direction with the outer tube 1 by means of screws 4 (shown in FIG. 1B) which are screwed in the direction perpendicular to the axial direction. Instead of screws 4 other fixation means can be applied to hold the tube motor 15 in position inside the outer tube 1.

The front flange 30 and the rear flange 31 are assembled on the tube motor 15. Both flanges 30, 31 have an outer profile which corresponds to the inner profile of the outer tube 1 such that the front flange 30 and the rear flange 31 can slide into the outer tube 1 and such that the front flange 30 and the rear flange 31 rotate the outer tube 1 when the tube motor 15 is rotating. In the embodiment of FIG. 1A, the outer profile of the front flange 30 and the rear flange 31 is corresponding to the outside profile of the inner tube 2. In an alternative embodiment, the profile of the front flange 30 and the rear flange 31 assembled on the tube motor 15 can have a different shape in order to fit the outer tube 1 and to transfer the power from the tube motor 15 to the tube 48.

FIG. 7B shows a cross section of the front flange 30 according to an embodiment of the present invention wherein the front flange has an outer profile with three recesses 33 for matching and engaging with protrusions of the outer tube 1. FIG. 7C shows a view on the rear flange 31. In this embodiment, the rear flange has similar recesses 32 to match and engage with protrusions of the outer tube 1.

The front flange 30 comprises also a cover portion 29, which covers the side of the tube when the tube motor 15 is full inserted inside the outer tube 1. Once the tube motor 15 is fully inserted in the outer tube 2, then the tube motor 15 can be fixed in axial direction in the outer tube, by inserting the screws 4 through the pre-drilled holes in the outer tube 1 and screwing the screws 4 in the front flange 30 of the tube motor 15.

At least part of the motor shaft 27 is positioned outside the outer tube 1 when the tube motor 15 is assembled in the outer tube. The backlash rubber 13 is provided on the motor shaft 27 and the motor pin 14 is inserted in the backlash rubber 13 and in a hole 26 of the motor shaft 27 as illustrated in FIG. 1A. The motor pin 14 holds the backlash rubber 13 in position at the motor shaft 27. The motor shaft 27 further comprises a hole 28, through which the motor cable is guided. The backlash rubber 13 is assembled on the motor shaft 27 as such that the side holes 43 are aligned with the hole 26 on the motor shaft. Once the holes of the backlash rubber 13 and the hole 26 on the motor shaft 27 are aligned, then the motor pin 14 can be inserted in the holes of the backlash rubber and through the hole 26 in the motor shaft.

The tube motor assembly 47 is, when mounted in a pool, fixed in a holder 46 which is first fixed to a pool wall. The motor pin 14 is used to fix the motor shaft 27 in a holder bottom 11 of the holder 46. The backlash rubber 13 dampens the reaction forces when the motor is activated. When the tube motor 15 is rotating, the motor shaft 27 remains fixed and the motor body with the front flange 30 and the rear flange 31 assembled to the motor is rotating. When the tube motor assembly 47 is positioned in the holder bottom 11, a holder top 12 is snap fit in the holder bottom 11 which fixes the motor shaft 27 and the backlash rubber 13 in axial direction in the holder bottom 11.

The holder bottom 12 is screwed in the sidewalls of a swimming pool by means of screws 9 and plugs 8. In an alternative embodiment bolts and anchors can be used to fix the holder bottom 11 to the sidewall of the swimming pool. In yet another embodiment the holder bottom 12 can be mounted and fixed on a hanging plate.

FIGS. 1A and 1D and FIGS. 8A and 8B illustrate the outer shaft bearing assembly 51. In the embodiment of FIG. 1A, the outer shaft bearing assembly 51 comprises an outer shaft bearing 18, a ball joint 16, a ball joint housing 17, a washer 19, a retaining washer 20 and a bolt 21. The outer shaft bearing 18 is inserted in the outer tube 1. The outer shaft bearing 18 is fixed in axial direction to the outer tube 1 by means of screws 4 (shown in FIG. 1B) which are screwed in the direction perpendicular to the axial direction. Instead of screws 4 other fixation means can be applied to hold the outer shaft bearing 18 in position inside the outer tube 1. In the embodiment of FIG. 1A, the outer shaft bearing 18 has an outer a profile which corresponds to the inner profile of the outer tube 1 such that the outer shaft bearing 18 can slide into the outer tube 1 and such that the outer tube 1 rotates the outer shaft bearing 18 when the motor is rotating.

The outer shaft bearing 18 can rotate freely on a shaft portion 35 of the ball joint 16. The ball joint 16 further comprises a spherical portion 36. Before the outer shaft bearing 18 is slid in the outer tube 1, the shaft portion 35 of the ball joint 16 is inserted through the hole in the ball joint housing 17. In the next step the shaft portion 35 of the ball joint assembly 16 is inserted in the central hole 44 of the outer shaft bearing 18. Then, the washer 19 is fixed to the shaft portion 35 of the ball joint 16 by using the retaining washer 20 and the bolt 21. In alternative embodiments, washer 19 may be fixed to the shaft 35 in another manner known in the art. The outer shaft bearing 18 also has recessed areas 45 to match and engage with protrusions of the outer tube 1. In this structure, the outer shaft bearing 18 can not only rotate around the shaft portion 35, the outer shaft bearing 18 can also move over the shaft portion 35 in the axial direction. The washer 19 ensures that the shaft portion 35 remains in the outer shaft bearing 18. As the outer shaft bearing can move axially on the shaft portion 35, also the tube mechanism assembly 49 can move axially on the shaft portion 35 of the ball joint 16 until the outer shaft bearing 18 hits the washer 19 which is screwed at the shaft end of the shaft portion 35 of the ball joint 16 with the screw 21 and retaining washer 20. In alternative embodiments other stopper known in the art may be used.

The outer shaft bearing assembly 51 is mounted in a second holder which is in the embodiment of FIG. 1A the same as the first holder 46 of the tube motor assembly 47. In an alternative embodiment are the first holder for the tube motor assembly 47 and the second holder for the outer shaft bearing assembly 51 different holders. The ball joint 16 with the ball joint housing 17 is positioned in the holder bottom 11. Once positioned is the holder top 12 snap fit in the holder bottom 11. By snap fitting the holder top 12 in the holder bottom 11 are the ball joint 16 and the ball joint housing 17 fixed in axial direction in the holder bottom 11. The shape of the ball joint 16 allows in this mounted position rotational freedom of the ball joint 16 inside the bottom holder 11 such that the tube 48 can be tilted while the ball joint 16 and the ball joint housing 17 are mounted in the second holder 46. The tube 48 with the tube motor assembly 47 connected to it on the one side and the outer shaft bearing 18 connected to it on the other side is together called the tube mechanism assembly 49. Because the outer shaft bearing 18 can freely rotate and move with respect to the shaft portion 35 of the ball joint 16, can the tube mechanism assembly 49 rotate and move in axial direction over the shaft portion 35 of the ball joint 16. Further, with the functionality that the ball joint 16 can rotate in the holder 46 when mounted, when the tube motor assembly 47 is detached from the first holder 46, the tube 48 can be tilted while the ball joint 16 remains in the second holder 46. The angle of rotational freedom towards the nominal axis defined by the axis of the tube when assembled in the holders 46 on both walls of the swimming pool, ranges from 0 to at least 20°. This embodiment of the present invention is illustrated in FIG. 4A. In the perspective view of FIG. 4A, the outer shaft bearing assembly 51 is mounted in the second holder 46. FIG. 4A illustrates that with the ball joint 16 fixed in the holder 46, the ball joint 16 can rotate in the ball joint housing 17 which remains fixed in the holder 46. The tube 48 with the tube motor assembly 47 can tilt 20° in all directions. This rotational freedom has many advantages. The rotational freedom allows the installer to install the cover mechanism by a single person. One can first mount the outer shaft bearing assembly 51 in the holder bottom 11. Once the ball joint 16 and the ball joint housing 17 is fixed with the holder top 12, the tube 48 can be rotated to mount at the other side of the tube 48 the tube motor assembly 47 in the first holder 46.

As shown in FIG. 4B, in the alternative embodiment wherein the tube 48 is a single tube 63, for example the outer tube 1, the tube motor assembly 47 and the outer shaft bearing assembly 51 are connected to both sides of the single tube. The single tube 63 can in the same way be tilted in all directions while the outer shaft bearing assembly 51 remains in the second holder 46.

FIGS. 2A and 2B show the cross section of respectively the inner tube 2 and the outer tube 1 according to an embodiment of the present invention. The cross sections of the inner tube 2 and the outer tube 1 illustrate that the outer profile of the inner tube 2 matches and engages with the inner profile of the outer tube 1. The matching of the outer profile of the inner tube 2 with the inner profile of the outer tube 1 enables proper engagement which allows power transmission between the outer 1 and the inner tube 2. Between the inner profile and the outer profile is a minimal clearance in rotational direction to avoid backlash.

In the embodiment of FIGS. 2A and 2B consist the outer profile of the inner tube 2 of three recessed areas 22 in the outer cylindrical circumference 24. The three recessed areas 22 are separated from each other under an angel of 120°. The three recessed areas 22 of the inner tube 2 match and engage with three protrusions 23 at the inner profile of the outer tube 1. The outside profile of the outer tube 1 has a cylindrical shape 25. The three protrusions 23 are equally spaced over the inside of the outer tube 1.

FIG. 3 further illustrates the outer tube 1 according to an embodiment of the present invention. The main drawing in FIG. 3 is a cross sectional view in longitudinal direction. In this view is indicated where a number of cross section views in radial direction are taken which are shown in separate section views. Section C-C shows the cross section of the outer tube 1 at the location indicated in the longitudinal view and which corresponds to the location where the tube motor assembly 47 or the outer shaft bearing 18 will be fixed by screws 4. The Section C-C shows that in this embodiment three countersunk holes 38 are provided in each protrusion 23 of the outer tube 1. Section B-B shows the cross section of the outer tube 1 at the location indicated in the longitudinal view and which corresponds to the location where a strap 52 is connected by a plug 5 which is press fit in the hole 39. Section D-D shows a further cross section of the outer tube 1 at the location indicated in the longitudinal view and which corresponds to the location where the inner tube 2 is connected with the outer tube 1 by inserting plugs 6 and screws 7 in the countersunk holes 40.

FIGS. 6A to 6C illustrate the assembly of a tube 48 according to an embodiment of the present invention. FIG. 6A illustrates the first step of assembling a part of the inner tube 2 in the outer tube 1. The inner tube 2 is inserted and slid in the first outer tube 1. Based on the width of the swimming pool and depending on the length of the tubes, it can be calculated how much the inner tube 2 needs to be inserted in the outer tube 1. The distance D is the distance of the inner tube 2 which needs to be inserted in the first outer tube 1. For the tube set with pool width range from 3.3 m to 4.5 m, the distance D is calculated as follows D=(5300−W)/2 whereby W is equal to the width of the pool. For the tube set with pool width range from 4.3 m to 5.5 m, the distance D is calculated as follows D=(6300−W)/2 whereby W is equal to the width of the pool.

FIG. 6B illustrate to connect the assembly of FIG. 6A to a second outer tube 1. The inner tube 2 is now inserted in the second outer tube 1. Based on the width of the swimming pool and depending on the length of the tubes, it can be calculate how much the inner tube needs to be inserted in the outer tube. The distance D is calculated in the same way as for the insertion in the first outer tube 1.

FIG. 6C illustrates the fixing of the outer tube 1 with the inner tube 2. Once the inner tube 2 is in the correct position in relation with the outer tubes 1, one has to drill holes in the inner tube 2 which correspond with the pre-drilled countersunk holes in the outer tube 2. Plugs 6 and screws 7 are inserted in the pre-drilled countersunk holes in the outer tube 1 and in the holes drilled in assembly in the outer tube 2. Once the plugs 6 and screws 7 are inserted, the screws 7 are tightened and as such the plugs 6 are pulled against the inner wall of the inner tube 2.

FIGS. 5A and 5B show two perspective views of a pool cover mechanism according to an embodiment of the present invention in two positions, once in an operational position and once in an installation or maintenance position. In the perspective view of FIG. 5A, the first holder and the tube motor assembly 47 is shown. In the perspective view of FIG. 5B, the second holder and the outer shaft bearing assembly 51 is shown. In the operational position, the tube motor assembly 47 is in the first holder 46. In the installation or maintenance position, the tube motor assembly 47 is dismounted from the first holder and the tube 48 is tilted while the outer shaft bearing assembly 51 is still in the second holder. Furthermore, as the tube mechanism assembly 49 can move in axial direction over the shaft portion 35 of the ball joint 16, the tube mechanism can also be moved in the direction of the arrow. This functionality allows the installer to get easily access to the tube motor when needed, for example when the tube motor 15 needs to be disassembled from or assembled in the tube 48 for repair or maintenance purposes. It also allows easy installation by one person. This functionality also allows for deviations on the tube length compared to the measured value of the width of the swimming pool.

The tube 48 is tilted up to a position where the tube motor side is above the water level of the pool and the tube mechanism assembly 49 is displaced along the shaft portion 35 of the ball joint 16. In this way, the end of tube 48 with the tube motor assembly 47 is beyond the edge 41 of the pool 50.

FIGS. 9A to 9D illustrate the steps for installing the outer shaft bearing assembly 51 in the second holder 46 which is fixed to a side wall of a swimming pool. The outer shaft bearing assembly 51, connected to tube 48, including the ball joint 16 is the first side to be mounted when installing a pool cover mechanism. The outer shaft bearing assembly 51 is mounted in the holder bottom 11 of the holder 46 by a drop-in assembly. The holder bottom 11 comprises a vertical slot that receives the ball joint housing 17. The vertical slot in the holder bottom 11 is extending horizontally in the direction away from the wall. Therefore, as illustrated in FIG. 9B, in a next step the ball joint holder 17 and the ball joint are pulled in the direction of the arrow such that the ball joint holder 17 moves in the horizontal slot. In this position, the ball joint holder is fixed in the vertical direction by the slot. In a next step, as illustrated in FIG. 9C, once the ball joint 16 and the ball joint housing 17 are in the correct position in the horizontal slot inside the holder bottom 11, the holder top 12 can be inserted and snap fit with the holder bottom 11. In this way, the holder top 12 closes also the axial freedom of the ball joint holder 17 in the second holder 46 such that the ball joint holder 17 is now at a fixed position in the second holder 46. To give feedback to the installer that the holder top 12 is installed correctly, the holder top 12 is configured to provide a click sound when the holder top 12 is in the correct position in the holder bottom 11. This is illustrated in FIG. 9D.

FIGS. 10A to 10D illustrate the steps for installing the tube motor assembly 47 in the first holder 46 which is fixed to a side wall of a swimming pool. The outer shaft bearing assembly 51 at the opposite side of the tube 48 is at that moment already mounted in the second holder. As illustrated in FIG. 10A, firstly the motor cable 34 needs to be connected and inserted in the cable guide or hole. Then, the tube mechanism assembly 49, including the tube 48, the tube motor assembly 47 and the outer shaft bearing 18, can move over the shaft 35 of the ball joint 16 while the ball joint 16 can tilt. By this movement, the tube motor assembly 47 with the backlash rubber 13 and the motor pin 14 can be dropped in the holder bottom 11. The holder bottom 11 has a vertical slot wherein the motor pin makes a vertical movement when the tube motor assembly 47 is dropped in the holder. The vertical slot is extending in a horizontal slot. Therefore, as illustrated in FIG. 10B, in a next step the backlash rubber 13 and the motor 14 are pulled in the direction of the arrow on FIG. 10B such that the motor pin 14 moves into the horizontal slot. In a next step, as illustrated in FIG. 10C, once the backlash rubber 13 and the motor pin 14 are in place in the horizontal slot of the holder bottom 11, the holder top 12 is inserted and snap fit with the holder bottom 11. If the holder top 12 is snap fit in the correct position a click sound is generated by the holder 46. This is illustrated in FIG. 10D. The sound provides a confirmation to the installer that holder is correctly closed.

FIGS. 11 to 14 illustrate how the straps 52 are connected to the slats 55 according to an embodiment of the present invention. The straps 52 are connected to the slats 55 by means of a slat connector 53 and a buckle 54 (shown in FIG. 13). The slat connector 53 is a C-shaped tube 57, which can slide over the typical hooks 56 of the slats 55. The hooks 56 can have different shapes. By having the C-shape, the C-shape tube 57 can be used for all kind of slats 55 with different designs of the hooks 56. The buckle 54 comprises a main area and two legs 60. The main area is used to hook a loop 61 of the strap. The two legs 60 are located at each side of the main part of the buckle 54 and are used to hook inside the slat connector 53.

The buckle 54 is inserted in the slat connector 53 from the slit side 58 (shown on FIG. 14) of the C-shaped tube 57. One end of the buckle 54 will be pulled through a slot 59 in the slat connector which is at the opposite side of the slit 58. The buckle 54 will be hold in position inside the slat connector 53 by means of the legs 60 of the buckle 54, which remain hooked inside the slat connector.

FIG. 12A illustrates the first step to assemble a strap 52 to the first slat 55 of the pool cover. A loop 61 of the strap 52 is inserted in the slot 59 of the slat connector 53. The buckle 54 is inserted in the loop 61 of the strap 52. As illustrated in 12B, in a next step, the loop 61 of the strap 52 is pulled inside the slat connector from the slit side 58 of the C-shaped tube 57 towards the slot 59. Once the buckle 54 is correctly positioned in the C-shaped tube 57 with the legs 60 hooked inside the slat connector, the slat connector 53 with the buckle 54 and the strap 52, is slid over the hooks 56 of the slat 55 in the direction of the arrow on FIG. 12C. The result is illustrated on FIG. 12D which shows the slat connector 53 with buckle 54 and strap 52 in position on the first slat 55.

Claims

1. A pool cover mechanism for winding and unwinding slats over a pool, the pool cover mechanism comprising a tube (1) for connecting with the slats (55);a tube motor assembly (47) for rotating the tube (1) wherein the tube motor assembly (47) is connected to the tube (1) at a first end and wherein the tube motor assembly (47) comprises a tube motor (15) and a non-rotating motor end (13, 27) when the tube motor (15) is rotating;a first holder (46) for receiving the non-rotating motor end (13, 27) of the tube motor assembly (47);an outer shaft bearing assembly (51) connected to the second end of the tube (1) wherein the outer shaft bearing assembly (51) is configured to allow rotation of the tube (1) when the tube motor (15) is rotating;a second holder (46) for receiving the outer shaft bearing assembly (51);wherein the outer shaft bearing assembly (51) and the second holder (46) are configured such that at least part of the outer shaft bearing assembly (51) can rotate in the second holder (46) when the tube (1) is tilted compared to the position of the tube wherein the motor end (13, 27) is in the first holder (46) and wherein the outer shaft bearing assembly (51) comprises a first group of elements (18) and a second group of elements (16, 17), wherein the first group of elements and the second group of elements are configured such that the first group of elements can do a sliding movement relative to the second group of elements in the axial direction of the tube (1).

2. A pool cover mechanism according to claim 1, wherein the outer shaft bearing assembly (51) comprises a ball joint (16) and a ball joint housing (17), wherein the ball joint (16) can rotate in the ball joint housing (17) when the ball joint housing (17) is received in the second holder (46) and the tube (1) is tilted compared to the position of the tube wherein the motor end is in the first holder.

3. A pool cover mechanism according to any one of the preceding claims, wherein the outer shaft bearing assembly (51) comprises an outer shaft bearing (18) connected to the second end of the tube (1).

4. A pool cover mechanism according to claim 3 when dependent on claim 2, wherein the outer shaft bearing (18) has a central opening, wherein the ball joint (16) has a shaft portion (35), and wherein the central opening and the ball joint (16) are configured such that the outer shaft bearing 18 can slide in the axial direction over the shaft portion (35).

5. A pool cover mechanism according to claim 4, wherein the outer bearing assembly further comprises a stopper (20) and wherein the stopper is configured such that the stopper limits the sliding of the outer shaft bearing (18) over the shaft portion (35).

6. A pool cover mechanism according to any one of the preceding claims, wherein the tube (1) is a single tube (63).

7. A pool cover mechanism according to any one of the preceding claims, wherein the tube (1) comprises at least two outer tubes (1) and at least one inner tube (2), wherein the inner tube (2) is configured to have an outer profile which corresponds to the inner profile of the outer tube (1) such that the inner tube (2) can slide into the outer tubes (1) and such that the inner tube (2) is rotating when the outer tube (1) is rotating.

8. A pool cover mechanism according to any one of the preceding claims, wherein the first holder (46) is identical to the second holder (46).

9. A pool cover mechanism according to any one of the preceding claims, wherein the first holder and the second holder are not identical.

10. A pool cover mechanism according to any one of the preceding claims, wherein the outer shaft bearing assembly (51) and the second holder (46) are configured such that the at least part of the outer shaft bearing assembly (51) can rotate in the second holder (46) between 0 and 20° when the tube (1) is tilted between 0 and 20° compared to the position of the tube wherein the motor end (13, 27) is in the first holder (46).

11. A pool cover mechanism for winding and unwinding slats over a pool, the pool cover mechanism comprising a tube (1) for connecting with the slats (55);a tube motor assembly (47) for rotating the tube (1) wherein the tube motor assembly (47) is connected to the tube (1) at a first end and wherein the tube motor assembly (47) comprises a tube motor (15) and a non-rotating motor end (13, 27) when the tube motor (15) is rotating;a first holder (46) for receiving the non-rotating motor end (13, 27) of the tube motor assembly (47);an outer shaft bearing assembly (51) connected to the second end of the tube (1) wherein the outer shaft bearing assembly (51) is configured to allow rotation of the tube (1) when the tube motor (75) is rotating;a second holder (46) for receiving the outer shaft bearing assembly (51);characterized in that the tube (1) comprises at least two outer tubes (1) and at least one inner tube (2), wherein the inner tube (2) is configured to have an outer profile which corresponds to the inner profile of the outer tube (1) such that the inner tube (2) can slide into the outer tubes (1) and such that the inner tube (2) is rotating when the outer tube (1) is rotating.

12. A pool cover mechanism according to claim 11 wherein the outer tube (1) has a cylindrical shaped outer profile (25).

13. A pool cover mechanism according to claim 11 or 12, wherein the inner profile of the outer tube (1) comprises at least one recess area (22) and wherein the outer profile of the inner tube (2) comprises at least one protrusion (23).

14. A pool cover mechanism according to any one of the preceding claims 11 to 13, wherein the at least two outer tubes (1) are fixed with respect to the at least one inner tube (2) such that the assembled at least two outer tubes and the at least one inner tube have a fixed length.

15. A pool cover mechanism according to any one of the preceding claims 11 to 14, wherein the at least two outer tubes (1) are fixed to the at least one inner tube (2) by at least one screw positioned in the at least one protrusion.

16. (canceled)

17. A pool cover mechanism according to any one of the preceding claims 11 to 16, wherein the inner profile (2) comprises three recessed areas and the outer profile (1) comprises three protrusions.

18. A pool cover mechanism according to any one of the preceding claims 11 to 17, wherein the tube (48) further comprises a strap link (3) assembled on the inner tube (2), wherein the strap link (3) has an outer profile with a cylindrical shape and with a diameter corresponding to the diameter of the outer cylindrical surface of the outer tube (1).

19. A pool cover mechanism for winding and unwinding a number of connected slats over a pool, the pool cover mechanism comprising a tube (1) for connecting with the slats (55);a tube motor assembly (47) for rotating the tube (1) wherein the tube motor assembly (47) is connected to the tube (1) at a first end and wherein the tube motor assembly (47) comprises a tube motor (15) and a non-rotating motor end (13, 27) when the tube motor (15) is rotating;a first holder (46) for receiving the non-rotating motor end (13, 27) of the tube motor assembly (47);an outer shaft bearing assembly (51) connected to the second end of the tube (1) wherein the outer shaft bearing assembly (51) is configured to allow rotation of the tube (1) when the tube motor (75) is rotating;a second holder (46) for receiving the outer shaft bearing assembly (51);at least one strap 52 connected to the tube (1),characterized in that the pool cover mechanism further comprisesat least one slat connector (53) for connecting the at least one strap (52) to the first slat of the number of connected slats (55), wherein the at least one slat connector (53) comprises a buckle (54) having two leg portions (60) and being configured to connect with the strap (52) and a C-shaped tube (57) having a slit (58) over the whole length of the C-shaped tube for sliding over a part of the slat and having a slot (59) in the C-shaped tube opposite to the slit for receiving the buckle, wherein the slot is configured such that the two leg portions (60) of the buckle (54) are anchored inside the C-shaped tube (57) when the buckle is connected to the strap.

20. A pool cover mechanism according to claim 19, wherein the strap (52) comprises a loop (61) and wherein the buckle is connected with the loop by arranging a part of the buckle in the loop while the legs (60) of the buckle are arranged in the C-shaped tube (57).

21. A pool cover mechanism according to claim 19 or claim 20, wherein the slit (58) is narrower at the ends of the C-shaped tube (57) compared to the middle of the C-shaped tube.