The present invention relates to an elevator car with a working platform.

This invention can be used in all kinds of elevators where the roof of the elevator car can be taken aside for instance for inspection, repair or maintenance work in the elevator shaft. The invention is useful particularly in elevators where the headroom is low. The headroom in this context means the clearance between the roof of the elevator car and the ceiling of the elevator shaft in the situation where the elevator car is at its uppermost position. In advantageous solutions, the headroom can be so low that the height of the elevator shaft is equal to the height of the floors of the building. In that case the elevator shaft can be totally inside the building.

Several operations, such as tests, inspections, adjustment operations, maintenance or repairs, are usually performed in the elevator shaft and often also at the upper part of the elevator shaft particularly in case the elevator machinery is situated on top of the elevator shaft in so-called machine room-less elevators. These operations are referred later in this context in a shorter way only as "maintenance work" .

In case service persons are working in the elevator shaft and particularly when they are working at uppermost part of the elevator shaft their safety has always to be secured. If the height of the top clearance of the elevator shaft is low, in other words the headroom is low, a sufficient safety space, which prevents injuries occurring for persons working at the upper part of the elevator shaft, cannot always be guaranteed without special procedures.

One solution according to the prior art to create a sufficient safety space in an elevator where the headroom is low is shown in the US patent No. US7337880B2. In this case the required free safety space is formed inside the elevator car. The US patent presents a solution where the roof of the elevator car is lowered, for maintenance work, into the interior space of the elevator car. The lowering is carried out with strong steel cables so that the lowered roof is hanging suspended by the steel cables in the interior space of the elevator car. Due to the operations and the movements of service persons the lowered car roof tends to move in the horizontal plane, which movements inside the elevator car disturb the maintenance work and may cause damages to the elevator car .

The solution of the US patent No. US7337880B2 aims to provide a remedy to this problem by using one or more separate mechanical stabilizing devices that are arranged between the lowered car roof and an inner wall of the elevator car. A problem in this solution is that the car roof must be so strong that it bears at least the weight of the service person and his/her tools. That leads to a heavy structure of the car roof. Another disadvantage is the use of the separate stabilizing devices. Installing and reinstalling the stabilizing devices take time, the stabilizing devices require room and capacity to carry them with, and it is also possible to forget them somewhere so that they are not available when they are needed. Another solution according to the prior art to create a sufficient safety space in an elevator where the headroom is low is shown in the US patent No. US6880678B1. Also in this case the required free safety space is formed inside the elevator car. This US patent presents two different solutions. The first solution reminds the solution of the US patent presented above. In that case a part of the elevator roof is lowered, for maintenance work, into the interior space of the elevator car. The lowered part of the roof forms the working platform. The rigid hangers that suspend the lowered roof are folded down from the roof structure and the ladders are folded down from lowered part of the roof. The hangers and the ladders are kept in their out-of-use position under the car roof in the space between the car roof and the illuminated ceiling.

The first solution of the US patent No. US6880678B1 has at least two main disadvantages, namely the lowered part of the roof must be strong enough to bear at least the weight of the maintenance persons and their tools. That leads to a heavy structure of the roof. Another disadvantage is that the space required for the storage or out-of-use position of the hangers, ladders and other components of the working platform between the car roof and the illuminated ceiling causes a need to make the elevator car higher, which further causes many other disadvantages.

The second solution presented in US6880678B1 shows a maintenance platform arrangement where a part of the roof of the elevator car is hinged to be turned downwards when setting up the maintenance platform assembly. The maintenance plat- form assembly itself is hinged to the upper side of the roof part and the ladders are hinged to the maintenance platform assembly. In their out-of-use position the maintenance platform assembly and ladders are folded on the roof of the elevator car. One problem in this solution is again the roof, particularly the part of the roof that is turned downwards. That part and its hinge must be strong enough to bear at least the weight of the maintenance persons and their tools. That leads to a heavy structure of the roof. Another disadvantage is that it is not possible to change the horizontal position of the platform.

One objective of the present invention is to eliminate drawbacks of prior art technology mentioned above and to achieve an elevator car with a working platform in an elevator where the headroom at the upper part of the elevator shaft can be as low as possible, and the elevator shaft is completely inside the building so that there is no need to penetrate the roof of the building. Another objective of the present invention is to create a safe working space inside the elevator car for maintenance work of the elevator appliances in the elevator shaft and the top part of the elevator car. And yet another objective of the present invention is to achieve a maintenance working platform that is easy and fast to assemble and disassemble and that moves with the elevator car, is safe to use and is totally invisible for the passengers of the elevator car. Yet one further objective of the present invention is to achieve a maintenance working platform that can easily be moved horizontally to the best possible position for the maintenance work. The elevator car with a working platform according to the invention is characterized by what is disclosed in claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims.

The inventive content of the application can also be defined differently than in the claims presented below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Likewise, the different details presented in connection with each embodiment can also be applied in other embodiments. In addition, it can be stated that at least some of the subordinate claims can, in at least some situations, be deemed to be inventive in their own right. In order to achieve the objectives of the present invention, the present invention provides an elevator car with a working platform which elevator car is equipped with an openable car roof and a maintenance platform assembly that has its storage position outside the elevator car and which mainte- nance platform assembly is arranged to be placed inside the elevator car when the car roof is open. Advantageously the maintenance platform assembly comprises a suspension part, a working platform and a support part which parts are hinged together with joints.

One advantage of the invention is that the invention enables maintenance work for the appliances at the top part of the elevator shaft without the need to step onto the roof of the elevator car. Thus, all the maintenance work can be done from inside the elevator car. Another advantage of the solution according to the invention is that a safe working space for elevator maintenance work is created inside the elevator car .

Yet another advantage is that the components of the maintenance platform assembly are placed outside the elevator car and to move with the elevator car. That leads to an advantage that the components of the maintenance platform assembly do not disturb the interior of the elevator car, and in addition, the roof of the elevator car do not need to bear the weight of the maintenance persons and their tools.

One further advantage of the solution according to the invention is that the solution makes it possible to move the working platform horizontally to the best possible location for the maintenance work.

Yet one further advantage of the invention is that the invention enables a safe way of providing an elevator that has an extremely low top clearance or headroom. The top clearance can even be minimized to the minimum, or close to the minimum, required only by the trajectory of the elevator car. Thus, when the elevator car is in its uppermost possible position on its trajectory, the shaft space above the elevator car is small and the height of the elevator shaft can easily be fitted inside the building, without penetrating the roof of the building. Yet another advantage is that the solution according to the invention is very easy and quick to use, and does require neither awkward working in the elevator shaft nor preliminary procedures at the top end or bottom end of the elevator shaft. Yet a further advantage is also that the solution is inexpensive and simple to implement.

In the following, the invention will be described in detail by the aid of example embodiments by referring to the at- tached simplified and diagrammatic drawings, wherein presents in a simplified and diagrammatic side view an elevator car according to the invention at the top part of an elevator shaft in a building having the elevator shaft with low headroom,

presents in a simplified and diagrammatic side view and the closest sidewall partially cut the elevator car according to Fig. 1 in the situation where the maintenance platform assembly is in its storage position on the roof of the elevator car,

presents in a simplified and diagrammatic side view and the closest sidewall partially cut the elevator car according to Fig. 1 in the situation where the maintenance platform assembly is placed in its first working position inside the elevator car, presents in a simplified and diagrammatic side view and the closest sidewall partially cut the elevator car according to Fig. 1 in the situation where the maintenance platform assembly of a second embodiment is placed in its first working position inside the elevator car, presents in a simplified and diagrammatic side view and the closest sidewall partially cut the elevator car according to Fig. 1 in the situation where the maintenance platform assembly is placed in its second working position inside the elevator car, presents in a simplified and diagrammatic side view the elevator car of the second embodiment of the invention in the situation where the maintenance platform assembly is in its storage position outside the elevator car,

presents in a simplified and diagrammatic side view the elevator car of the third embodiment of the invention in the situation where the maintenance platform assembly is in its storage position outside the elevator car,

presents in a simplified and diagrammatic side view the elevator car of according to Fig. 7 in the situation where the maintenance platform assembly is moved into the interior of the elevator car, and presents in a simplified and diagrammatic side view the elevator car of according to Fig. 7 in the situation where the maintenance platform assembly is in its working position inside the elevator car.

An object of the present invention is to achieve an elevator car having an easily openable lightweight roof, which makes it possible to place a maintenance platform assembly inside the elevator car in order to access maintenance and repair targets in an elevator shaft and in the outer upper part of the elevator car from inside the elevator car, and which also removes the need to step onto the roof of the elevator car, and in addition to that, also makes it possible to reduce the height of the elevator shaft needed.

Figure 1 presents in a simplified and diagrammatic side view the upper part of an elevator with an elevator car 2 according to the invention at the top part of an elevator shaft 1 in a building having the elevator shaft 1 with low headroom.

The elevator car 2 is arranged to run up and down in the el- evator shaft 1 along guide rails 3. The elevator also comprises an elevator machinery 4 that is advantageously placed at the top part of the elevator shaft 1, fastened, for instance into one of the guide rails 3. The elevator car 2 comprises among other things a car door 5, an openable roof 2a and a maintenance platform assembly 6 that is folded on the roof 2a of the elevator car 2 outside the elevator car 2 when the platform 6 is in its storage position. Advantageously the car roof 2a comprises a group of roof elements 2b that are hinged to each other so that the roof 2a can be opened by folding the roof elements 2b together. Advantageously the maintenance platform assembly 6 is movably or slidably connected to the first roof element 2b, and is locked to the first roof element 2b in its stor- age position.

Figure 2 presents the same elevator car 2 in the same situation as figure 1 but now the closest sidewall 2c of the elevator car 2 has been partially cut away so that a part of the interior of the elevator car 2 is visible. The interior of the elevator car 2 comprises at least a corner casing 8 that is fastened at an upper corner inside the elevator car 2, preferably onto a sidewall of the elevator car 2. The corner casing 8 may comprise car lighting and other electrical appliances, including all printed circuit boards needed by an elevator car, a reserve battery with its charger, and also apertures for elevator car ventilation. In addition, the corner casing 8 comprises a maintenance control unit 9 that is behind a separate hinged lid 9a that can be opened though the car roof 2a is in its closed position. The lock of the lid 9a can be opened with a special key, for example with the same key as the control center of the elevator or with a so-called triangle key that is used to open landing doors in the inspection mode of the elevator. The maintenance control unit 9 comprises, among other things, an arrangement to operate the opening and closing mechanism of the locking of the roof 2a.

Advantageously the foldable roof 2a of the elevator car 2 has been divided into four roof elements 2b that are hinged together. In smaller elevator cars, the number of roof ele- ments 2b of the same kind can be only two. All the roof elements 2b are installed into a support rail that act also as a guide rail. The support rail is fastened horizontally on top of the elevator car 2 and is strong enough to bear the weight of roof 2a, maintenance platform assembly 6, mainte- nance persons and their tools. One or more pressure sensors have been placed in connection with the support rail to measure a load on the closed roof 2a in order to control if there is someone on the roof 2a when the roof 2a is closed. For the sake of clarity, the support rail is not presented in figures. The number of the support rails can also be more than one, for instance two, symmetrically one m each side of the elevator car 2.

The first and the last roof element 2b comprise first control switches that are arranged to prevent opening the roof 2a without an authorization if someone tries to open the roof 2a using the opening and closing mechanism of the locking arrangement of the roof 2a. The first and the last roof element 2b also comprise second control switches that are arranged to control that the car roof 2a is locked in its closed position, after which the elevator is ready for the normal use.

Figure 3 presents in a simplified and diagrammatic side view and the closest sidewall 2c partially cut the elevator car 2 according to Fig. 2 in the situation where the maintenance platform assembly 6 is placed in its working position inside the elevator car 2. In that position the maintenance platform assembly 6 is firmly supported on the floor 2d of the elevator car 2.

The maintenance platform assembly 6 is movably or slidably connected to the first roof element 2b as mentioned above. The folding mechanism of the car roof 2a and the folding mechanism of the maintenance platform assembly 6 are arranged to work together so that when the two first roof elements 2b of the roof 2a are opened and raised to an upright position, the maintenance platform assembly 6 movably connected to the first roof element 2b has also turned into the upright position. By opening the locking of the storage position of the maintenance platform assembly 6 the maintenance platform assembly 6 can be slidably descended downwards up to the floor 2d of the elevator car 2. In that situation, the first part or suspension part 6a of the maintenance platform assembly 6 is suspended at its first end by its supporting point 7 that is fastened to the first roof element 2b or to another suitable fastening point in the support structure of the car roof 2a. Advantageously the suspension part 6a of the maintenance platform assembly 6 is slidably mounted in the first roof element 2b.

The second part 6b of the maintenance platform assembly 6 that act as a working platform is hinged at its first end to the second end of the first part 6a with a first joint 6d. Correspondingly the working platform 6b is hinged at its second end with a second joint 6d to the first end of the third part 6c of the maintenance platform assembly 6. Finally, the third part 6c of the maintenance platform assembly 6 is supported at its second end on the floor 2d of the elevator car 2. The third part 6c acts as a support part. When the maintenance platform assembly 6 is set up in this way for maintenance work the working platform 6b is in substantially horizontal position at the height where the mainte- nance person can perform his/her maintenance tasks for the appliances in the elevator shaft 1 or outside the upper part of the elevator car 2.

Figure 4 presents in a simplified and diagrammatic side view and the closest sidewall 2c partially cut the elevator car 2 according to Fig. 3 in the same situation as in Fig. 3. The only difference is that the maintenance platform assembly 6 now comprises an additional support leg 6e or a pair of support legs 6e that are supported on the floor 2d of the ele- vator car 2. Each additional support leg 6e is hinged to the maintenance platform assembly 6 with a joint, such as the joint 6d. The additional support makes the working platform 6b very stable, which eases the maintenance work.

Figure 5 presents in a simplified and diagrammatic side view and the closest sidewall partially cut the elevator car 2 according to Fig. 1 in the situation where the maintenance platform assembly 6 is placed in its second working position inside the elevator car 2. The maintenance platform assembly 6 has been arranged to be moved horizontally when it is descended in its working position. In the case presented in Fig. 5, all the roof elements 2b are opened and raised to an upright position, and the roof elements 2b with maintenance platform assembly 6 are moved horizontally to the position desired. To prevent unintentional movements of the working platform 6b the arrangement comprises a locking mechanism to lock the opened roof elements 2b in a desired location. This improves safety at work.

Figures 6-9 present other advantageous embodiments of the invention. In the embodiments shown in figures 6-9 the basic structure of the maintenance platform assembly 6 can advantageously be similar to the structure presented in connec- tion with figures 1-5. In that case the basic structure of maintenance platform assembly 6 comprises the first part 6a that is suspended at its first end by its supporting point, second part 6b constituting the working platform and the third part 6c forming a support leg against the floor 2d of the elevator car 2, which all parts 6a, 6b and 6c are hinged together with the joints 6d. Figure 6 presents in a simplified and diagrammatic side view the elevator car 2 of the second embodiment of the invention in the situation where the maintenance platform assembly 6 is in its storage position outside the elevator car, to be precise, on a sidewall of the elevator car 2. The car roof structure can be similar to the structure shown in figures 1 to 5 but in this embodiment it is different. The roof 2a of the elevator car 2 comprises two halves 2e that are hinged at their outer edges to the top edges of the elevator car 2 so that the car roof 2a can be opened by turning the halves 2e open starting from the center of the roof 2a.

The maintenance platform assembly 6 is connected to the upper part of a sidewall of the elevator car 2 with a support and hinge mechanism 10 that supports the maintenance platform assembly 6 in its storage position and allows the maintenance platform assembly 6 to be turned inside the elevator car 2 over the upper edge of the elevator car 2. Inside the elevator car 2 the maintenance platform assembly 6 is connected to a support rail arrangement that act also as a guide rail. Advantageously the support rail arrangement can comprise one or two parallel rails, and is fastened horizontally on top of the elevator car 2, and is strong enough to bear the weight of maintenance platform assembly 6, maintenance persons and their tools. The maintenance platform assembly 6 is arranged to be moved horizontally along the rail or rails of the support rail arrangement, and to be locked in a desired location. The support rail arrangement is not presented in the figures.

Figures 7-9 present in a simplified and diagrammatic side view the elevator car 2 of the third embodiment of the in- vention. In figure 7 the maintenance platform assembly 6 is in its storage position outside the elevator car 2, in figure 8 the maintenance platform assembly 6 is just moved into the interior of the elevator car 2, and in figure 9 the maintenance platform assembly 6 is in its working position inside the elevator car 2.

The car roof structure can be similar to the structure shown in figures 1 to 5 or 6 but in this embodiment it is differ- ent . The roof 2a of the elevator car 2 comprises one large roof plate 2f that are supported by linear actuators 11 fastened to the elevator car 2. The linear actuators 11 move the roof plate 2f in the vertical direction up and down. The maintenance platform assembly 6 is connected to the upper part of the back wall of the elevator car 2 with a support and hinge mechanism 10 that comprises a support and hinge element 10a and a support and moving element 10b. The support and hinge element 10a is arranged to support the maintenance platform assembly 6 in its storage position and to allow the maintenance platform assembly 6 to be turned inside the elevator car 2 over the upper edge of the elevator car 2. Correspondingly the support and moving element 10b inside the elevator car 2 is arranged to support the maintenance platform assembly 6 in its working position and to facilitate the moving of the maintenance platform assembly 6 in a horizontal direction. The support and moving element 10b is connected to be moved on a rail or rails of the support rail arrangement that acts also as a guide rail. The support rail arrangement is fastened horizontally on top of the elevator car 2 and is strong enough to bear the weight of maintenance platform assembly 6, maintenance persons and their tools. The support rail arrangement is not presented in the figures.

It is obvious to the person skilled in the art that the in- vention is not restricted to the examples described above but that it may be varied within the scope of the claims presented below. Thus, for instance the roof structure of the elevator car and the mechanisms for opening and closing the roof can be different from what is presented above.