The invention relates to a revolving door comprising a wall or walls in which openings for inlet and outlet of per- sons and/or objects are provided, and comprising rotatable door wings that during use are rotatable around an imaginary central vertical axis in a passage area surrounded by the wall or walls, wherein each of said door wings is provided with a slidable door wing part for extending and/or retracting the door wing of which it forms a part.

Such a revolving door is known since the early 90s of the previous century. Both US 5,634,295 and EP 0 715 049 teach a revolving door with door wings of the telescopic type,

wherein each door wing has a slidable door wing part that is movable into a casing of the door wing, wherein the casing extends radially from the wall in the direction of the imaginary central vertical axis. When the slidable door wing parts are moved into their respective casings a middle part of the passage area between the walls is freed or can be freed from any hindrance by pivoting away the casings, as required in cases of panic to provide an unhindered flea way.

DE 42 11 861 teaches another revolving door with door wings of the telescopic type, wherein each door wing has a slidable door wing part that is movable into a casing of the door wing, wherein the casing extends radially from the imaginary central vertical axis towards the wall or walls. The slidable door wing parts that move along the wall or walls are retracted when they pass the opening or openings in order to prevent pinching of a person or a person' s finger between the door wing and the edge of the opening in the wall or walls.

It is an object of the invention to provide a revolving door of improved versatility and flexibility in use.

It is another object of the invention to provide a revolving door which can be attuned also after its placement to the momentary needs existing where the revolving door is erected, which needs may vary during the day.

It is another object of the invention to provide a revolving door which is usable both as a security door, and as a door that enables quickly passing of a high number of people .

It is still another object of the invention to provide a revolving door meeting high-security demands and re ^¬ sistance against breaking and entry.

It is still another object of the invention to improve the door's resistance against draught.

To promote these objects and to acquire other advantages that will become apparent from the following disclosure, the revolving door of the invention has the features of one or more of the appended claims. It is expressly noted that the features that are mentioned in the claims can be applied independent from each other or in a cumulative way in order to face the demands of the situation.

In a first aspect of the revolving door of the inven ^¬ tion each of its door wings substantially comprises slidable door wing parts only, so as to provide that the slidable door wing parts of any single door wing are selectable to be placed in at least two positions, a first position wherein said door wing parts are entirely adjacent or next to each other and wherein edges of said door wing parts are adjacent to the wall or walls, and wherein said door wing parts extend radially away from said wall or walls towards the central vertical axis, and a second position wherein said door wing parts are en ^¬ tirely adjacent or next to each other and wherein edges of said door wing parts are adjacent to the central vertical ax ^¬ is, and wherein said door wing parts extend radially away from the central vertical axis towards the wall or walls. With this construction the door of the invention is provided with tremendous versatility and offers its user a large amount of flexibility and various possible uses of the door. Several examples of that will be provided hereinafter with reference to the drawing of multiple operational uses of the door of the invention.

Preferably the slidable door wing parts of any door wing are radially movable back-and-forth past the imaginary central vertical axis between opposite positions relative to said imaginary central vertical axis. As already mentioned above in general, this feature can be applied in addition to or independently from the feature in the previous paragraph. To further promote the door's flexibility the slida- ble door wing parts of any door wing are at all times placea- ble next or adjacent to each other, or essentially in each other's extended direction, or in any intermediate relative position with respect to each other. It is also a preferred feature according to the invention that each single slidable door wing part of any door wing is positionable either closer to the wall than to the central vertical axis, or closer to the central vertical axis than to the wall. This further con- tributes to the high flexibility of the door of the invention.

It is further preferred that during use wherein es ^¬ sentially the door wings extend from the imaginary central vertical axis up to the wall or walls, a slidable door wing part of a door wing that approaches an opening or -when the door wings are stationary- that is near to an opening, retracts away from the wall to give way from the passage area delimited by the walls towards the opening. A swift passing of the revolving door is then possible, also in case the door is otherwise restricted from moving.

One other nice feature of the revolving door of the invention is that it is arranged that during use when the door wings rotate, the slidable door wing parts of each door wing are simultaneously retractable away from the wall or walls. The eventual completely retracted position of the slidable door wing parts corresponds to the situation in which the revolving door has come to a full stop and remains stationary, wherein passage of the door is then enabled by reason of the retracted slidable door wing parts. The simultaneous retrac ^¬ tion of the door wing parts during rotation of the door wings makes a quick conversion possible from a conventional use of the revolving door wherein it rotates, to the situation that the door is stationary and passing of the door is only enabled by the retracted slidable door wing parts.

Another possible use of the revolving door of the in- vention occurs when the door is provided with first sensor means, and further is equipped with the feature that rotation of the door wings is interruptible depending on the first sensor means, wherein selected door wings of the door define a confined area delimited by the wall and wherein access to or leaving said confined area is prevented, and wherein the door wing parts of at least one of the remaining door wings are op ^¬ erational to provide a conventional sliding door to enable passing the passage area independent from the time that is re- quired for scrutinizing or investigating the person or object in the confined area. Rotation of the revolving door and the other persons are therefore not obstructed in case there is something that otherwise would prevent the revolving door from continuing its rotation.

Yet another preferred and beneficial feature of the revolving door of the invention is that the passage area is provided with second sensor means and that during use wherein essentially the door wings extend from the central vertical axis up to the wall or walls, a slidable door wing part of a door wing that threatens to be obstructed by a passant in the passage area as observed by the second sensor means, is arranged to retract away from the wall so as to move past said passant and to resume its original relative position with reference to the remainder of the door wing after said door wing is completely passed said passant as observed by said second sensor means.

Another beneficial feature is that when the revolving door has a night door or night doors to close off the openings, it is preferable that edges of the slidable door wing parts of the door wings are positionable against the night door or night doors to support said door or doors against the force of wind and/or against the forces of breaking and entry.

Yet another preferred feature of the door of the invention is that during standstill of the revolving door edges of the slidable door wing parts of the door wings are intimately positionable against the wall or walls to provide very effective draught resistance.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of a revolving door according to the invention that is not limiting as to the appended claims.

In the drawing:

-figures 1 - 11 show different embodiments of a revolving door according to the invention. Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

Making first reference to figure 1 a revolving door 1 is shown comprising a wall or walls 2, 3 in which openings 4, 5 for inlet and outlet of persons 6 and/or objects are provid ^¬ ed. The door 1 has rotatable door wings 7 that during use are rotatable around an imaginary central vertical axis 8 in a passage area 9 surrounded by the wall or walls 2, 3. So far the door of the invention corresponds to the door of the prior art. The invention resides in a particular aspect of the feature which is also known per se, notably that each of said door wings 7 is provided with a slidable door wing part for extending and/or retracting the door wing 7 of which it forms a part. As acknowledged hereinabove this feature is per se known from US 5,634,295; EP 0 715 049 and DE 42 11 861.

According to the invention each of said door wings 7 substantially comprises slidable door wing parts 7', Ί' ' only, therewith avoiding fixed door wing parts (casings) as are known from the mentioned prior art so as to provide that the slidable door wing parts 7', 7'' of any single door wing 7 are selectable to be placed in at least two positions as shown in figure 2A and figure 2B. Figure 2B shows a first position wherein said door wing parts 7', 1' ' are entirely adjacent or next to each other and wherein edges 10 of said door wing parts 7', 1'' are adjacent to the wall or walls 2, 3, and wherein said door wing parts 7', 1' ' extend radially away from said wall or walls 2, 3 towards the imaginary central vertical axis 8 (the figure shows a dot, but this is imaginary since actually there is a void) . Figure 2A shows a second position wherein said door wing parts 7', 1' ' are entirely adjacent or next to each other and wherein edges 11 of said door wing parts 7', 1'' are adjacent to the imaginary central vertical axis 8, and wherein said door wing parts 7', 7'' extend radially away from the central vertical axis 8 towards the wall or walls 2,3.

Figures 3, 4 and 5 show three different embodiments of the revolving door 1 of the invention which are all made possible by the feature that the slidable door wing parts 7' , 1' ' of any door wing 7 are radially movable back-and-forth past the imaginary central vertical axis 8 between opposite positions relative to said imaginary central vertical axis 8. This means that all door wings 7 of the door 1 according to the invention can be positioned at the same side of the door with reference to the imaginary central vertical axis 8 as shown in figure 3, 4 and 5. In fact this feature is applicable as figure 3 shows, independent from whether the slidable wing parts 7', 7'' are positioned next or adjacent to each other as explained hereinabove with reference to figure 2A and 2B. The slidable wing parts 7', 7'' can also be placed in each other's extended direction according to figure 3.

On the other hand Figure 4 and figure 5 show the sit ^¬ uation that the slidable wing parts 7', 7'' are together closer to a wall 3 than to the imaginary central axis 8 (figure 4) or are closer to the imaginary central axis 8 then to the wall 3 (figure 5). This latter option is beneficial for the situa ^¬ tion that two streams of people are moving in opposite direc ^¬ tions, wherein a larger part 9' of the passage space 9 can be reserved for the higher amount of people passing per unit of time, and the smaller part 9' ' of the passage space 9 can be available for the lower amount of people that is passing the door 1 per unit of time.

From the foregoing it will be clear that the slidable door wing parts 7', 7'' of any door wing 7 are at all times placeable next to each other or essentially in each other' s extended direction or in any intermediate relative position with respect to each other, and that each single slidable door wing part 7', 1'' of any door wing 7 is positionable either closer to the wall 2, 3 than to the imaginary central vertical axis 8, or closer to the imaginary central vertical axis 8 than to the wall 2, 3. This enables that during regular use of the door 1 of the invention as shown in figure 6, wherein dur ^¬ ing the larger part of the rotational movement of the door wings, said door wings 7 extend from the central vertical axis 8 up to the wall or walls 2, 3, the door wings 7 are arranged such that a slidable door wing part 7' of a door wing 7 that approaches an opening 5 gives way to a person 6 from the passage area 9 to the opening 5. This enables that the person 6 can earlier leave the passage area 9 without having to wait until the concerning door wing 7 has progressed far enough beyond the concerning edge of the opening 5. It is also possible -when rotation of the revolving door 1 has stopped and the door wings 7 are stationary which may be caused for instance by another person 6' blocking the door as is shown in figure 7- that the door wing part 1' that is near to an opening 5, is arranged to retract away from the wall 3 to give way to the first mentioned person 6 from the passage area 9 to the opening 5.

Figures 8A - 8D relate to a sequence of situations wherein during use when the door wings rotate 7 as shown in figure 8A, the slidable door wing parts 1' of each door wing 7 are simultaneously and progressively retracted away from the wall or walls 2, 3 as illustrated in figures 8B - 8D. This provides for a dynamic conversion from a regular operation of the revolving door 1 of the invention wherein the door wings rotate as shown in figure 8A and also depicted in figure 1 to a stationary positioning of the slidable door wing parts 7', 7'' close to the imaginary vertical axis 8 of the door, which is shown in figure 8D and also depicted in figure 2A.

Use of the revolving door 1 of the invention as secu ^¬ rity door is shown with reference to figures 9A - 9C. The re ^¬ volving door 1 is provided with first sensor means 12, for instance a camera. The revolving door is arranged such that ro ^¬ tation of the door wings 7 is interruptible depending on the first sensor means 12. In figure 9A a person 6 is monitored and denied access to the building where the revolving door 1 provides access to. In that situation rotation of the door wings 7 is interrupted and depending on the rotational posi ^¬ tion of the door wings 7, selected door wings 7.1 and 7.2 of the door 1 are arranged to define a confined area 13 delimited by the wall 2 wherein access to or leaving said confined area 13 is prevented. Person 6 can be kept secured in the confined area 13 to wait for appropriate authorities who can take fur ^¬ ther care of this person. At the same time and whilst the con ^¬ fined area 13 is kept secured, a door wing part of at least one of the remaining door wings 7.3 can be maintained opera ^¬ tional as a conventional sliding door to enable another person 6' passing the passage area. In figure 9B the situation is shown that the person 6 is granted access, and a movable door wing part of door wing 7.2 is retracted to give way to person 6 towards opening 4. In figure 9C another situation is shown wherein person 6 is denied access again. In that situation leaving the confined area 13 is made possible at the side where the person 6 originally came in by retracting a movable wing part of sliding door 7.1, to enable that the person 6 leaves the confined area 13 yet is indeed denied access to the building where the revolving door 1 is placed.

Figures 11A and 11B show an option of the revolving door of the invention wherein the door is prevented from being obstructed by a still standing person 6. For that purpose the door is provided with the features that the passage area 9 is provided with second sensor means 13, for instance a camera, and that during use wherein essentially the door wings 7 extend from the central vertical axis 8 up to the wall or walls 2, a slidable door wing part 1' of a door wing 7.1 that threatens to be obstructed by said still standing person 6 in the passage area 9 as observed by the second sensor means 13, is arranged to retract away from the wall 2 so as to move past said still standing person 6 as shown in figure 11A. Figure 11 B shows that the slidable door wing part 1' of door wing 7.1 is returning to its original relative position with reference to the remainder of the door wing 7 after said door wing is completely passed said still standing person 6 as observed by said second sensor means 13.

Figure 10 finally shows an embodiment of the revolving door 1 of the invention provided with a night door 14 to close off the opening 5, wherein an edge 10 of a slidable door wing part 7' of the door wing 7 is positionable against the night door 14 to support said door against the force of wind and/or against the forces of breaking and entry. Comparably but for a different purpose the edges 10 of the slidable door wing parts 7' of the door wings 7 can also be arranged to be intimately positionable against the wall or walls 2, 3 to provide optimal draught resistance at the time the door wings 7 have ceased rotating and are stationary.

Although the invention has been discussed in the foregoing with reference to several exemplary embodiments of the revolving door of the invention, the invention is not restricted to these particular embodiments which can further be varied in many ways without departing from the invention. The discussed exemplary embodiments shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiments are merely intended to explain the wording of the appended claims without intent to limit the claims to the exemplary embodiments. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using the exempla ^¬ ry embodiments.