| CLAIMS 1. Sliding door assembly (100), comprising: a sliding door panel (10) having an upper end and a lower end; a suspension system (5, 11; 50; 150) for slideably carrying the upper end of the door panel (10); a guiding arrangement for guiding the lower end of the door panel (100), wherein the guiding arrangement comprises a confinement system (20) for confining horizontal movement of the door's lower end in a direction perpendicular to the sliding direction; wherein said confinement system is a magnetic confinement system. 2. Sliding door assembly according to claim 1, wherein the magnetic confinement system (20) comprises a first magnetic member (21) associated with the lower end of the door panel (10) and a second magnetic member (22) for being mounted stationary, said magnetic members (21, 22) being designed for exerting an attractive force on each other. 3. Sliding door assembly according to claim 2, wherein one of said magnetic members comprises an elongate strip of a magnetizeable material, or wherein at least one of said magnetic members comprises an elongate strip of a magnetic material . 4. Sliding door assembly according to claim 2 or 3, wherein the first magnetic member (21) is mounted at the lowermost point of the door panel (10) . 5. Sliding door assembly according to claim 2 or 3, wherein the first magnetic member (21) is mounted on the outer surface of the door panel (10) and wherein the lower end of the door panel (10) extends below the first magnetic member (21) . 6. Sliding door assembly according to any of claims 2-5, wherein, in a rest condition, the first and second magnetic members are positioned vertically above each other and the mutual attractive magnetic force is directed vertically, and wherein, on deviation from the rest position by the lower end of the door panel (10), the attractive magnetic force on the first magnetic member (21) has a horizontal reset component forcing the lower end of the door panel back to its rest position . 7. Sliding door assembly (100), comprising: a sliding door panel (10) having an upper end and a lower end; a suspension system (50; 150) for slideably carrying the upper end of the door panel (10); a guiding arrangement for guiding the lower end of the door panel (100), wherein the guiding arrangement comprises a confinement system (7, 12; 20) for confining horizontal movement of the door's lower end in a direction perpendicular to the sliding direction; wherein said suspension system is a magnetic suspension system. 8. Sliding door assembly according to claim 7, wherein the magnetic suspension system comprises: first magnetic means (54; 153, 154) attached to the upper end of the door panel; a horizontal carrier bar (5) for being mounted stationary; second magnetic means (52; 151, 152) attached to the horizontal carrier bar; said first and second magnetic means being designed for exerting a repulsive vertical force on each other. 9. Sliding door assembly according to claim 8, wherein at least one of said magnetic means comprises an elongate strip of a magnetic material. 10. Sliding door assembly according to claim 8 or 9, wherein the second magnetic means (52) comprise a longitudinal groove (53) in its upper surface while the first magnetic means (54) has a projection extending downwards in said groove, or wherein the first magnetic means (54) has a longitudinal groove in its lower surface while the second magnetic means (52) has a projection extending upwards in said groove. 11. Sliding door assembly according to claim 8 or 9, wherein the second magnetic means comprise two substantially parallel magnetic strips (151, 152) with mutually parallel magnetic . orientation; wherein the first magnetic means comprise at least one magnet (153, 154) aligned with a respective one of said magnetic strips (151, 152) and having magnetic orientation opposite to the magnetic orientation of said magnetic strips (151, 152); the system further being provided with a stabilizing magnet (155) attached to the upper end of the door panel, positioned between said two magnetic strips (151, 152) and having magnetic orientation parallel to the magnetic orientation of said magnetic strips (151, 152) . 12. Sliding door assembly (100), comprising: a sliding door panel (10) having an upper end and a lower end; a suspension system (50; 150) for slideably carrying the upper end of the door panel (10); a guiding arrangement for guiding the lower end of the door panel (100), wherein the guiding arrangement comprises a confinement system (20) for confining horizontal movement of the door's lower end in a direction perpendicular to the sliding direction; wherein said suspension system is a magnetic suspension system and wherein said confinement system is a magnetic confinement system. 13. Sliding door assembly according to claim 12, further having the features of any of claims 2-6 and/or further having the features of any of claims 8-11. Shower cabin (1), comprising a sliding door assembly ording to any of the previous claims. 15. Shower cabin (1), comprising a sliding door assembly according to any of the previous claims 2-6, wherein the second magnetic member (22) is mounted on or in a floor (2) o the cabin, or wherein the second magnetic member (22) is mounted on or in a threshold (3) of the cabin. |
FIELD OF THE INVENTION
The present invention relates in general to sliding doors. Particularly, the invention relates to a sliding door for a shower cabin or a steam cabin, but the principles of the present invention can also be applied in sliding doors for other purposes, for instance cabinet doors or even sliding separation panels for separating large rooms into small rooms.
BACKGROUND OF THE INVENTION
Figure 1 is a schematic cross section of a sliding door assembly for a shower cabin 1 according to the prior art. The cabin has a floor 2 and a threshold 3 below an entrance opening 4. Above the entrance opening 4, the cabin has a horizontal frame bar 5. A guide rail 6, having an L-shaped or U-shaped cross section, is fixed to the frame bar 5 at the interior side of the cabin.
A door panel 10 is mounted in the door opening 4, so that it can slide sidewards such as to open and close the cabin 1; in the drawing, the sliding direction is perpendicular to the plane of drawing. To this end, the upper end of the door panel 10 has carrier wheels 11 riding in the upper guide rail 6; in other words, the door panel is suspended from the frame member 5.
For preventing the lower end of the door panel to move away from the door opening 4, into the interior of the cabin, the lower end of the door panel 10 has guide wheels 12
engaging in a lower guide rail 7 mounted to the interior side wall of the threshold 3. The cross section of this lower guide rail 7 typically has the shape of an inverted U or of an L with. horizontal leg part 13 and a foot part 14 directed downwards. Mounting the door panel 10 would involve the steps of;, first hooking the guide wheels 12 in the lower guide rail 7, i f-ting the panel until the carrier wheels 11 are higher that the upper guide rail 6, placing the carrier wheels 11 into the upper guide rail 6, and lowering the door panel 10 until the carrier wheels 11 rest on the bottom of the upper guide rail 6. The dimensions are such that the guide wheels 12 are still within the lower guide rail 7, mechanically limiting the horizontal freedom of movement of the lower end of the door panel 10.
SUMMARY OF THE INVENTION
Although such door design functions properly, there are some disadvantages. The threshold 3 must be relatively high, which is annoying because the user has to step over this high threshold, and aesthetically it looks rather bulky. Further, the door panel 10 necessarily is placed a few centimetres inside the shower cabin, with respect to the threshold 3, thus reducing the room available inside the shower cabin. Further, the lower guide rail 7 tends to collect dirt and is difficult to clean. Further, the lower guide rail 7 may be sensitive to wear and tear. Also, the process of placing or removing the door panel is rather difficult.
Further, in corner cabins it is customary to have two straight walls and one door opening with a quarter-circular footprint, to be closed by two 45° door panels. Such door panel is to be guided partly along the door opening (thus a curved path) and partly along a straight wall (thus a straight path); combining these requirements is difficult in prior art.
The present invention aims to eliminate or at least reduce these problems.
To this end, the present invention proposes that the lower end of- the door is held in position magnetically. The lower guide rail 7 and the guide wheel 12 can be omitted entirely, so the threshold 3 can be designed much lower. In fact, it is even possible to omit the threshold 3 entirely.
Likewise, the present invention proposes to use magnets for the upper suspension means, in order to achieve same or similar advantages at the upper end of the door. BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features and advantages of the present invention will be further explained by the following description of a preferred embodiment of the sliding door according to the present invention with reference to the drawings, in which same reference numerals indicate same or similar parts, and in which:
figure 1 is a schematic cross section of a sliding door assembly for a shower cabin according to the prior art;
figure 2A schematically shows a magnetic confinement system for a sliding door according to the present invention;
figure 2B schematically illustrates the operation of the invention;
figure 3 schematically shows some details of an embodiment of the invention;
figure 4 schematically shows some details of another
embodiment of the invention;
figure 5 schematically shows some details of yet another embodiment of the invention;
figure 6 schematically shows a magnetic suspension for a sliding door according to the present invention;
figure 7 schematically illustrates a shower cabin according to the present invention;
figure 8 schematically shows some details of a practical implementation of a magnetic suspension for a sliding door according to the- present invention.
DETAILED DESCRIPTION OF THE INVENTION
Figure 2A schematically shows a cross section of a lower part of a sliding door " assembly 100 for a shower cabin
according to the present invention. Specifically, the figure only shows the lower end of the door panel 10 and the upper end of the threshold 3. The door panel 10 may be carried at its upper end by a carrier arrangement having the same design as prior art as illustrated in figure 1, so there is no need to show and describe it again. Also, the floor 2 is not shown here . The sliding door assembly 100 comprises a magnetic confinement system 20, comprising at least one first magnet 21 mounted at the lower end of the door panel 10 and at least one second magnet 22 mounted at the upper side of the threshold 3, these magnets being oriented such as to exert a mutually attracting force on each other. Although the type of magnet is not essential, it is preferred to use so-called supermagnets or powermagnets (neodymium) in view of the strong forces these magnets can exert even if they are only small.
When comparing with figure 1, it should immediately be clear that the horizontal distance of the door panel 10 from the threshold 3 has reduced, so the interior room of a shower cabin increases. Further, when the door panel is mounted correctly, the vertical distance between the door panel 10 and the threshold 3 can be maintained to be very small, in the order of . 1-2 mm, without the door panel 10 and the threshold 3 ever touching each other, so there is no more wear and tear while further the design offers better protection against splashing water. Further, it should be clear that the design has little or no tendency to collect dirt, and is very easy to clean. As far as placing the door panel is concerned, it should be clear that this process has been simplified since the user only needs to lift the door and place the upper carrier wheels in the upper guide rail, during which the door panel may be held oblique and after which the door panel is swayed to its vertical orientation: the magnets automatically "catch" each other.
Figure 2B schematically illustrates the operation of the magnets 21 and 22. When the door panel 10 is displaced
horizontally, perpendicular to it own surface, i.e.
perpendicular to its normal sliding direction, the mutually attractive force exerted by the magnets 21, 22 gets a
horizontal component that urges the door panel 10 back to its rest position shown in figure 2A. The door panel 10 will give way to small horizontal forces without making any rattling noise, as the prior art panel would do. Ultimately, a user may exert a horizontal force large enough so that the magnetic force is overcome and the magnets become disengaged, for instance when it is intended to dismount the door panel.
While the basic principle of the present invention has been explained in the above, there are several variations possible.
First, since the lower guide rail is no longer present, the threshold 3 can be dispensed with, and the second magnet 22 can be mounted directly to the floor.
Further, instead of having two magnets mounted to the door panel and the threshold or floor, respectively, it is possible to have one magnet mounted to the door panel and a piece of magnetizeable material, such as steel, mounted to the threshold or floor, or vice versa.
Further, it is to be noted that magnetic force is
required irrespective of the sliding position of the door panel. Consequently, the first magnet 21 of the door panel has a horizontal extent along the width of the door, either in the form of a plurality of individual magnets or in the form of one elongate magnet. Alternatively or additionally, the second magnet 22 of the threshold or floor has a horizontal extent along the sliding path of the door panel, either in the form of a plurality of individual magnets or in the form of one elongate magnet. In this respect, it is noted that an
embodiment with only individual magnets is less preferred, because this leads to an uneven sliding resistance. Therefore, it is preferred to have an embodiment wherein either the first magnet 21 or the second magnet 22 is implemented as one longitudinal strip of magnet material. It would be possible to have both the first magnet 21 and the second magnet 22
implemented as a longitudinal strip of magnet material, with the first magnet 21 for instance extending over the entire horizontal extent of the door; in order to prevent that the attractive force would depend on the length of overlap between these two strips and hence on the door's sliding position, the second magnet 22 preferably extends over the entire path of the first magnet 21. The same would apply if one magnet is implemented as a longitudinal strip of magnet material while the other one is implemented as a longitudinal strip of magnetizeable material (e.g. steel). In the following, the phrase "magnetic member" will be used to cover a true intrinsic magnet as well as a
magnetizeable material.
In figure 2A, the second magnetic member 22 is shown as being mounted on top of the threshold 3. Instead, the second magnetic member 22 can be mounted in a recess of the threshold or floor. Figure 3 schematically shows an embodiment where the second magnetic member 22 is recessed in the floor 2 and is covered by a floor cover 23, illustrating that the second magnetic member 22 can be totally invisible. In a similar manner, the second magnetic member 22 can be totally invisible recessed in a threshold, if it is desired to have a threshold.
Further, it is possible to have a threshold arranged in front of the location of the second magnetic member 22 in the floor 2.
Figure 4 schematically shows an embodiment where a threshold 3 is stepped, with, located at the cabin side of the threshold 3, a plateau 33 below the top level of the threshold 3 while the second magnetic member 22 is recessed in the top surface of this plateau 33. Such design offers the advantages of good protection against water getting out of the cabin, a low building height of the threshold, and good cleanability of the threshold.
As far as the first magnetic member 21 is concerned, this may be attached externally onto the door panel 10, but it may also be mounted inside the panel 10 and/or within a cover such as to be invisible and not accessible by water. An example of such embodiment is illustrated in figure 4. In this
embodiment, the door panel 10 comprises a door frame 25 and a glass pane 26, and the first magnetic member 21 is arranged inside the door frame 25.
In the embodiment of figure 4, the first magnetic member 21 is arranged substantially in the central plane of the door panel 10, within a door frame. For several reasons, it may be that the door panel 10 is without frame and consist only of a glass pane. In such case, recessing' the first magnetic member 21 within the door panel 10 would be less easy. Further, it may be desirable to have an even better protection agains splashing water passing the door panel.
Figure 5 illustrates an embodiment wherein the first magnetic member 21 is arranged on the outer surface of the door glass pane 26 while the door glass pane 26 extends below the first magnetic member 21 to have a good overlap with a threshold 3. The first magnetic member 21 may be attached to the glass pane 26 through a suitable adhesive, or for instance with one or more screws extending through respective holes in the glass pane, but this is not shown for sake of simplicity. The figure shows the first magnetic member 21 attached to the glass pane 26 directly (with a distance member in between) , but it is also possible that the first magnetic member 21 is accomodated in a cover member attached to the pane.
In a preferred embodiment, the arrangement of carrier wheels 11 at the upper end of the door panel is replaced by a magnetic suspension system 50. In this case, magnets are used with like poles directed towards each other such as to exert repulsive forces on each other.
Figure 6 schematically shows a cross section of an upper part of a sliding door assembly 100 for a shower cabin
according to the present invention. Specifically, the figure only shows the upper end of the door panel 10 and a horizontal carrier bar 5, which at is side directed to the cabin interior is provided with a support rail 51. In the support rail 51, a magnetic strip 52 is mounted, having a groove 53 in its upper surface. Instead of being supported in a support rail 51, the magnetic strip 52 may also be mounted to the carrier bar 5 directly.
At its upper side, the door panel 10 is provided with a magnet 54, projecting downwards from a support 55 attached to the door panel 10. The magnet 54 is located in the groove 53 of the magnetic strip 52. In the embodiment shown, the magnet 54 and the groove 53 both have a V-shaped cross section, but different shapes of cross section are also possible, for instance a U-shape.
It is noted that the orientation of the magnetic
suspension system 50 may alternatively be inverted: in such case, a member with a groove at its lower end would be
attached to the door panel 10 while a member projecting upwards into the groove would be attached to the carrier bar 5, both having a corresponding cross section, such as a
Λ-shaped cross section, an inverted U-shape, etc.
The repulsive force of the magnetic strip 52 on the magnet 54 is generally upwards, with a self-centering effect due to the V-shaped or U-shaped or similarly shaped cross section of the groove 53. The magnetic strip 52 may be
symmetrical, but an asymmetric shape is also advantageous. In the embodiment shown, the side of the strip 52 directed to the door panel 10 is higher than the opposite side of the strip. When mounting the door panel 10, the magnet 54 is lifted over the free edge of the strip 52. Under the influence of gravity, the magnet 54 is lowered towards the magnetic strip 52, and the repulsive magnetic force presses the magnet 54 to the centre of the groove 53, although the precise horizontal position of the magnet 54 is not essential. Lowering the magnet 54 causes the repulsive vertical force to increase, until finally the door panel is fully supported by the
magnetic repulsion.
Figure 8 is comparable to figure 6, illustrating a magnetic suspension system 150 which is a variation of the magnetic suspension system 50 discussed above and which is easier to implement. Again, the horizontal carrier bar 5 is, at is side directed to the cabin interior, provided with a support rail 51, and at least one support 55 is attached to the door panel 10. Preferably, the door panel 10 is provided with at least two of such supports.
In the support rail 51, two magnetic strips 151, 152 are mounted parallel next to each other and at a horizontal spacing with respect to each other. The magnetic orientations of the two magnetic strips 151, 152 are substantially vertical and parallel to each other. For sake of illustration, like poles are indicated by like graphical filling.
At the lower side of the support 55, two magnets 153, 154 are mounted, wherein the mutual distance between these two magnets 153, 154 substantially corresponds to the distance between the two magnetic strips 151, 152. The magnetic
orientations of the two magnets 153, 154 are opposite to the magnetic orientations of the two magnetic strips 151, 152, so that in the operative condition, when the two magnets 153, 154 are positioned above the two magnetic strips 151, 152, respectively (as shown in the figure) , a vertically upwards repulsive force is exerted on the magnets 153, 154 and hence on the door panel 10. It is noted that in principle one of said magnets 153, 154 would be sufficient.
In order to keep the door panel 10 in place in the horizontal direction (i.e. the left-right direction in the drawing) , a stabilizing magnet 155 is attached to the support 55. The magnetic orientation of the stabilizing magnet 155 is opposite to the magnetic orientations of the two magnets 153, 154, hence parallel to the magnetic orientations of the two magnetic strips 151, 152. In the operative condition, the stabilizing magnet 155 is located between the two magnetic strips 151, 152. It can easily bee seen that the stabilizing magnet 155 is pushed away by each of said magnetic strips 151, 152 and therefore finds an equilibrium position between said strips without touching any of said strips.
It is noted that, alternatively, the stabilizing magnet attached to the support 55 may be replaced by a stabilizing magnetic strip mounted to the support rail 51, located between the two magnets 153, 154 and having magnetic orientation parallel to the two magnets 153, 154.
The dimensioning of the magnetic suspension system 50; 150 is such that it is capable of exerting sufficient vertical force with sufficient margin. It is noted that the sliding door assembly may have a magnetic suspension system in
combination with a prior art mechanical confinement system, but preferably has the magnetic suspension system 50; 150 in combination with the magnetic confinement system 20, as illustrated in figure 7. In that case, the door panel 10 is subjected to vertical down forces of gravity and of the magnetic confinement system 20, which will be indicated as Fg and Fc, respectively. The magnetic suspension system 50; 150 exerts vertical lifting force FL. In equilibrium, FL = Fg + Fc applies. If the position of the door panel 10 is lowered (by whatever external force) over a distance Δζ, the distance between the first and second magnets 21, 22 decreases so the downward attractive force Fc on the door panel increases by an amount
Likewise, the distance between the magnetic strip 52 and the magnet 54, or between the magnets 153, 154 and the strips
151, 152, decreases so the upward lifting force FL on the door panel increases by an amount
dFL
AFL = Az - ~—
dz
The equilibrium is stable (or a new equilibrium will be reached) if AFL > AFc applies, or
dFL dFc
>
dz dz
This condition is generally met if the magnets of the suspension system 50; 150 are much stronger than the magnets of the confinement system 20. It is noted that the magnets 21 and 22 of the magnetic confinement system 20 exert a maximum downforce Fcm when their distance has become zero. Likewise, it is noted that the magnets 52, 54 or 151, 152,- 153, 154 of the magnetic suspension system 50; 150 exert a maximum upforce FLm when their distance has become zero. One feature of a stable equilibrium is that FLm > FCm + Fg applies. However, when mounting the system one has to take care that there always is sufficient play in both magnetic systems: if, in figure 7, the supporting magnet 52 is mounted too low, it can easily be seen that the magnet 21 would scrape the floor cover 23. Thus, the vertical distance between the frame-bound magnets 22 and 52 or 151, 152 should be larger than the vertical distance between the door-bound magnets 21 and 54 or 153, 154.
It is further noted that, with stronger magnets of the suspension system 50; 150, the equilibrium is reached with larger vertical margin in the suspension system 50; 150. Thus, the present invention provides a sliding door assembly 100 comprising:
a sliding door panel 10 having an upper end and a lower end; a suspension system 50/ 150 for slideably carrying the upper end of the door panel 10;
a guiding arrangement for guiding the lower end of the door panel 100, wherein the guiding arrangement comprises a
confinement system 20 for confining horizontal movement of the door's lower end in a direction perpendicular to the sliding direction.
According to the invention, said confinement system is a magnetic confinement system or said suspension system is a magnetic suspension system, or both.
In view of the lack of any mechanical contact, there is no wear and tear, and the sliding door panel 10 can slide conveniently and smoothly without any mechanical resistance. There is hardly or no tendency to collect dirt, and in any case the assembly is easy to clean.
While the invention has been illustrated and described in detail in the drawings and foregoing description, it should be clear to a person skilled in the art that such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments; rather, several variations and
modifications are possible within the protective scope of the invention as defined in the appending claims. For instance, although it is preferred that a sliding door comprises a magnetic suspension system in combination with a magnetic confinement system, it is within the scope of the present invention that a magnetic suspension system is used in
combination with a prior art (non-magnetic) confinement system.
Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in
practicing the claimed invention, from a study of the
drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements, and the indefinite "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a
combination of these measures cannot be used to advantage.
Any reference signs in the claims should not be construed as limiting the scope.