The present invention relates to an elevator arrangement as defined in the preamble of claim 1.

The invention in question relates particularly to an eleva tor where a 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 when the elevator car is at its uppermost position. Various tasks, such as inspections, adjustment works, maintenance or re pairs, later referred in a shorter way only as "maintenance work", are often performed at the upper part of the elevator shaft. In that case, the safety of the persons performing the tasks mentioned above 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 on the roof of the elevator car, cannot always be guaranteed with out special procedures.

Usually the maintenance work is done on the roof of the ele vator car. In that case, when working on the roof of the el evator car an unintentional movement of the elevator car must be prevented in some other way than by the regular op erating brakes of the elevator. It is known in the prior art that this kind of prevention can be done by locking the ele vator car and/or the counterweight into their positions on the guide rail, for instance by means of a safety gear, a latch or wedges. However, this often requires that the work ing persons must separately go to the elevator shaft and perform the locking. That makes safety preparation tasks awkward, laborious and time-consuming. Another solution according to prior art for achieving an ad equate safety space in the upper part of an elevator shaft is to use one or more turnable buffers that are disposed be low the counterweight. The buffer is lifted upright before going onto the roof of the elevator car. The length of the buffer is such that the movement of the counterweight, and at the same time the movement of the elevator car, stops be fore the elevator car rises too high with respect to the ceiling of the elevator shaft. One problem, among others, in this solution is, however, that the shaft space might have been dimensioned so precisely that there is no proper space in the bottom part of the elevator shaft for a turnable buffer. Another problem is that the aforementioned buffer ensuring the top safety space is in the bottom part of the elevator shaft, i.e. right at the other end of the elevator shaft. In that case installing the buffer into the safe po sition takes extra time and it may also happen that for this reason the person in charge does not remember to go down to the bottom of the elevator shaft to turn them into the safe position .

In addition to the aforementioned, the safety solutions are often based on electrical supervision controls installed in the doors of the shaft, which controls must be switched to the safe position before going onto the roof of the elevator car. Turning the buffers into the safe position and activa tion of the electrical control circuits are often such a complex combination that, particularly e.g. with small tasks, they might be left undone owing to their complexity and for saving the time used. In addition, electrical super vision control systems could be susceptible to failure.

Yet one solution according to the prior art is shown in the US patent publication No. US2010/0200339 A1. The solution according to the US publication presents an elevator safety system for elevators with a reduced upper end of the eleva tor shaft. In this solution, the roof of the elevator car cannot be used as a working base, because the roof of the elevator car is constructed so that it does not support weight. Thus, it is not possible to be or work on the roof of the elevator car. In this case, the required free safety space is formed completely inside the elevator car when the elevator car is in its uppermost position. As the roof is not designed to bear loads, in such a situation a weight on the roof may deform or even broke the roof structures. The maintenance work at the top part of the elevator shaft is done inside the elevator car. For this purpose, a part of the side wall of the car is made removable and the mainte nance work is done through the opening in the side wall when the part mentioned above has been removed from the side wall. However, the problem in this solution is the fact that there are only limited possibilities to make inspection, re pair and maintenance work because only one certain opening is used. And likewise, there are limited possibilities to place elevator appliances that require regular maintenance in the elevator shaft because the opening is only at one side wall of the car. In addition, the opening makes the wall structure more expensive, more complicated and also weaker than the unbroken wall structure.

Also other solutions where an opening for maintenance work is formed to a wall of the elevator car are known in prior art. For example, there can be a maintenance hatch in a wall of the elevator car and the opening for maintenance work is arranged to be formed by opening this maintenance hatch. However, these kinds of solutions have similar problems as the solution presented in the US patent publication No. US2010/0200339 A1. Another disadvantage is that a mainte- nance hatch affects the visual appearance of the car wall and complicates cleaning of the wall .

One objective of the present invention is to eliminate draw backs of prior art technology and to achieve an elevator ar rangement where there is no need to make any kind of mainte nance work on the roof of the elevator car, but that kind of maintenance work can be done from the floor of the elevator car. Another objective of the present invention is to achieve an elevator arrangement 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. Yet another objective of the present invention is to achieve an elevator arrangement where the installation of the eleva tor components into the elevator shaft can be safely made from the floor of the elevator car.

The elevator arrangement according to the invention is char acterized by what is disclosed in the characterization part of claim 1. Other embodiments of the invention are charac terized 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 in ventive content may also consist of several separate inven tions, 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 present ed 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 mentioned above, the pre sent invention provides an elevator arrangement having an elevator comprising an elevator car arranged to run up and down in an elevator shaft along guide rails. The elevator car comprises a frame structure and at least walls, car door, a floor and a roof. The walls are connected to the frame structure and at least part of at least one wall is arranged to be moved vertically downwards and upwards to form an opening for safe working connection from inside the elevator car to the elevator shaft.

One advantage of the solution according to the invention is that the targets requiring inspection, service, repairing or maintenance are easily accessible from a safe place in the elevator car through the openable walls and the door of the elevator car. Yet another advantage is that the elevator car can be run so up in the elevator shaft that all maintenance work to also the uppermost parts can be made from the floor of the elevator car without using scaffoldings, stands or corresponding means. Thus, there is no need to access to the roof of the car during maintenance work, which makes the maintenance work easier and safer.

Another advantage is that the solution is very easy and quick to use, and requires neither awkward working in the elevator shaft nor preliminary procedures at the top end or bottom end of the elevator shaft. Yet another advantage is also that the solution is inexpensive and simple to imple ment . Yet a further advantage of the invention is that the inven tion 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 mini- mum, required only by the trajectory of the elevator car. Thus, when the elevator car is in its uppermost possible po sition 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.

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

Fig. 1 presents in a simplified and diagrammatic oblique top view a frame structure of an elevator car ac cording to the invention,

Fig . 2 presents in a simplified and diagrammatic side view an elevator car according to the invention when the walls of the car are in their normal position,

Fig . 3 presents in a simplified and diagrammatic side view an elevator car according to Fig. 2 when three side wall panels of the car are lowered, and maintenance work is in progress, and

Fig. 4 presents in a simplified and diagrammatic side view an elevator car according to the invention when an installation of the elevator is in progress. An aspect of the invention is to achieve an elevator ar rangement with an elevator car having several possibilities to access maintenance and repair targets in an elevator shaft from inside the elevator car, and which also removes the need to step onto the roof of the elevator car. In addi- tion, another aspect of the invention is to achieve an ele vator arrangement that reduces the height of the elevator shaft needed.

Figure 1 presents in a simplified and diagrammatic oblique top view a frame structure of an elevator car. The frame structure 1 is made, for example, of metal bars, which have been connected to each other to form a rectangular frame structure, to which the walls, the floor and the roof of the elevator car are arranged to be connected. Preferably, the frame structure 1 comprises four vertical corner bars, two vertical middle bars and horizontal bars to connect all the vertical bars together as a complete frame structure. The vertical corner bars at the front edge of the elevator car 2 act as the first corner guides 11a for the movable side walls of the elevator car 2, and the vertical corner bars at the back edge of the elevator car 2 act as the second corner guides lib for the movable side walls of the elevator car 2. The vertical middle bars substantially in the center of both the side walls act as middle guides 11 for the movable side walls of the elevator car 2. Preferably a sling for the ele vator car is also arranged to be connected to the frame structure 1.

Figure 2 presents in a simplified and diagrammatic side view an elevator car according to one embodiment of the invention in a situation where the car walls are in their normal posi tion. The elevator car 2 is arranged to run up and down in an elevator shaft along guide rails 3. The elevator car 2 is mounted inside a sling, which is not shown in the figures for the sake of clarity. The elevator car 2 comprises among others a back wall 4, side walls 5, a front wall 6, a car door 6a, a roof 7, a floor 8, a doorstep 9 and a top track 10. In addition, the elevator car 2 comprises a frame struc- ture, to which at least the side walls 5 are connected. The frame structure 1 comprises at least two vertical middle guides 11, which are essentially of the height of the eleva tor car 2 and located substantially at the center of the both sides of the elevator car 2. The side walls 5 are ar ranged to be moved vertically downwards and upwards at least along the middle guides 11.

Figure 3 presents in a simplified and diagrammatic side view an elevator car 2 according to Fig. 2 in a situation where the car walls are being lowered. In this embodiment of the invention, both of the side walls 5 of the elevator car 2 are composed of two separate wall panels 5a-5d, which are connected to the frame structure 1 of the elevator car 2. The height of the wall panels 5a-5d is essentially the same as the height of the elevator car 2. At one of their verti cal edges, the wall panels 5a-5d are connected to the middle guides 11. In this embodiment of the invention, the second vertical edges of the wall panels 5a and 5c are connected to the first corner guides 11a and the second vertical edges of the wall panels 5b and 5d are connected to the second corner guides lib. The corner guides 11a and lib belong to the frame structure 1 and they are shown in Fig. 1.

Advantageously, in addition to guiding surfaces, the verti cal guides 11, 11a and lib comprise vertical sliding surfac es along which the movable wall panels 5a, 5b, 5d can be slid guided in the vertical direction.

In the situation of the Fig. 3 a maintenance task is in pro gress. The elevator car 2 has been run with a service run or inspection run in an appropriate location in the elevator shaft so that the working person 15 being inside the eleva tor car 2 can have an easy access to the elevator components and appliances in the elevator shaft. In this case the car has been run to the upper part of the elevator shaft to the highest floor level 14. The working person 15 is standing on the floor of the elevator car 2 performing the maintenance task for the hoisting machinery 12. The two wall panels 5a and 5b of the frontmost side wall are lowered so that the upper edges of the wall panels 5a and 5b are about at the level of the vertical midpoint of the elevator car 2 forming an opening to the elevator shaft. The upper edges of the wall panels are also arranged to form a safety barrier to prevent the working person 15 to fall out of the elevator car 2.

The backmost side wall comprises two wall panels 5c and 5d. The first wall panel 5c, to which the control panel 13 of the elevator car 2 is attached, is not arranged to be moved but the second wall panel 5d has been lowered from the roof 7 of the elevator car 2 also forming an opening to the ele vator shaft so that it is possible to access the hoisting machinery 12 from the elevator car 2.

The elevator comprises also locking mechanism for the slida bly movable wall panels 5a, 5b and 5d, which locking mecha nism is arranged to lock the wall panels at their normal po sitions when the elevator is in normal use. When maintenance work is to be done, the working person unlocks the needed wall panels, moves them to an appropriate height needed and locks them there. The locking mechanism can be e.g. a me chanical latch or an electrical mechanism or some other suitable mechanism.

The wall panels 5a, 5b, 5d can be moved manually, but pref erably they are arranged to be moved with help of a power unit, such as an electric motor, which the working person 15 has brought with him.

Figure 4 presents in a simplified and diagrammatic side view an elevator car according to the invention in a situation where the elevator is being installed. At this phase of in stallation, the side walls 5 are not yet installed to the elevator car 2. Instead, there are temporary balustrades 16 at the side and/or back edges of the elevator car 2, which balustrades 16 prevent the working person 15 to fall from the elevator car 2. When installing the elevator, there are also temporary toe guards 18 at the side edges of the eleva tor car and the actual toe guard 17 at the front edge of the elevator car is arranged to act as a transport means for guide rail elements 3a and possibly also some other elements and components of the elevator. The toe guard 17 is hollow and the top edge is open so that elements to be transported can be put inside the toe guard 17. At the end of the in stallation, when the toe guard 17 is not needed anymore for transporting elements, the toe guard 17 is turned so that the open edge is not at the top of the toe guard 17. At the end of the installation also the balustrades 16 are removed and the wall panels 5a-5d are installed to form side walls 5 of the elevator car 2.

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 frame structure, the guides and the structure of the elevator can be also differ ent from what is presented above.