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

The invention in question relates suitably to an elevator 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 ele vator car is at its uppermost position. Various tasks, such as inspections, adjustment works, maintenance or repairs, 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 without 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 sidewall of the car is made removable and the maintenance work is done through the opening in the sidewall when the part mentioned above has been removed from the sidewall. However, the problem in this solution is the fact that there are only limited possibilities to make inspection, repair 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 sidewall of the car. In addition the opening makes the wall structure more expensive, more complicated and also weaker than the unbroken wall structure.

One objective of the present invention is to eliminate draw- backs of prior art technology and to achieve an elevator ar rangement where the headroom at the upper part of the eleva tor shaft can be as low as possible, and the elevator shaft can be completely inside the building so that there is no need to penetrate the roof of the building. Another objec- tive of the present invention is to achieve a safe space for maintenance work of the elevator appliances in the elevator shaft .

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 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 mentioned above, the pre sent invention provides an elevator arrangement an openable car roof, which arrangement comprising an elevator having an elevator car arranged to run up and down in an elevator shaft along guide rails, and which elevator car is equipped with an openable roof comprising two or more movable roof elements. Advantageously the arrangement comprises a locking adjustment to prevent the roof elements from moving and to finish an outward appearance of the ceiling of the elevator car . An elevator arrangement of the invention comprises an open- able car roof, the openable roof comprising two or more mov able roof elements and a locking adjustment to prevent at least one of the roof elements from moving. Advantageously locking adjustment contributes to finishing the appearance of the ceiling of the elevator car. Advantageously the lock ing adjustment prevents each of the roof elements from mov ing .

One advantage of the invention is that the invention enables a safe way of providing an elevator that can have an ex tremely 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. Another important advantage of the solution according to the invention is that the objects requiring service, repairing or maintenance are easily accessible from the safe place in the elevator car through the openable roof of the elevator car. Yet another advantage is that the solu- tion is very easy and quick to use, and does require neither awkward working in the elevator shaft nor preliminary proce dures at the top end or bottom end of the elevator shaft. Yet a further advantage is that the locking element arrange ment can be used also for decorative purposes in the ceiling of the elevator car. 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 Fig. 1 presents in a simplified and diagrammatic back view a part of the building where the back wall of the elevator shaft is removed, and an elevator in the elevator shaft, in which elevator the solution ac cording to the invention can be used,

Fig. 2 presents in a simplified and diagrammatic back view the upper part of the elevator shaft in the build ing according to Fig. 1,

Fig . 3 presents in a simplified and diagrammatic back view the upper part of the elevator shaft in the build ing according to Fig. 1 in the situation where the maintenance or repair task is in progress,

Fig . 4 presents in a simplified and diagrammatic oblique top view an upper part of the elevator car accord ing to the invention cross-sectioned just behind the front wall and the roof closed,

Fig . 5 presents in a simplified and diagrammatic oblique top view an upper part of the elevator car accord ing to the invention cross-sectioned just behind the front wall and the roof opened for maintenance work,

Fig . 6 presents in a simplified and diagrammatic oblique top view an upper part of the elevator car accord ing to the invention seen from behind and a half of the roof opened for maintenance work,

Fig. 7 presents in a simplified and diagrammatic front view an advantageous car roof structure according to the invention, Fig 8 presents in a simplified and diagrammatic front view a locking plate in the car roof structure ac cording to the invention,

Fig 9 presents in a simplified and diagrammatic front view another advantageous car roof structure ac cording to the invention,

Fig 10 presents in a simplified and diagrammatic front view the roof structure according to the Fig. 9 where the roof and the locking plate are separated from each other,

Fig 11 presents in a simplified and diagrammatic front view yet another advantageous car roof structure according to the invention, and

Fig 12 presents in a simplified and diagrammatic front view the roof structure of Fig. 11 where the roof elements are placed one upon the other and a man hole making a connection to the elevator shaft is created . An aspect of the invention is to achieve an elevator ar rangement with an elevator car having an openable roof, which makes it possible to access maintenance and repair targets in an elevator shaft from inside the elevator car, and which also reduces the height of the elevator shaft needed.

Figure 1 presents in a simplified and diagrammatic back view a part of the building 1 where the back wall of the elevator shaft lc is removed, and an elevator in the elevator shaft lc, in which elevator the solution according to the inven tion can be used. The building 1 has a roof la just above the elevator shaft lc and four floors lb served by the ele vator. The number of floors lb can vary. The elevator comprises among other things an elevator car 2 with an openable roof 2a, which elevator car 2 is arranged to run up and down in the elevator shaft lc along guide rails 3, and a counterweight or balance weight 2e that is also arranged to run up and down in the elevator shaft lc along its guide rails which are not presented in figure 1 for the sake of clarity. Later in this connection only bal ance weight 2e is mentioned when either counterweight or balance weight is meant.

Advantageously the supporting and moving of the elevator car 2 are separated from each other. This makes it possible to achieve an elevator structure where the height of the head- room above the elevator car 2 can be is low as possible. The elevator car 2 is driven by a hoisting machinery 8 equipped with a drive wheel 7. Advantageously, the hoisting machinery 8 is located at the bottom part of the elevator shaft lc, below the elevator car 2 and advantageously below the first floor level lb.

A traction member 6 is connected between the balance weight 2e and the elevator car 2. The traction member 6 can be a single member or a bunch of similar parallel members, for instance, the traction member 6 can be a toothed belt, chain or other type of member that does not slip on the drive wheel 7. In this embodiment the suspension ratio of the traction member 6 is 2:1. In that case the first end of the traction member 6 is secured at its first fastening point 9, for example at the bottom part of the elevator shaft lc. From the first fastening point 9 the traction member 6 is led upwards to go over and around a traction sheave 2g in connection with the balance weight 2e and from the traction sheave 2g the traction member 6 is led downwards to go under and around a diverting pulley 6b and the drive wheel 7 of the hoisting machinery 8 at the bottom part of the elevator shaft lc, from where the traction member 6 continues upwards to go over and around diverting pulleys 6c at the bottom of the elevator car 2 and from the diverting pulleys 6c again downwards to its second fastening point 9a where the second end of the traction member 6 is secured, for example at the bottom part of the elevator shaft lc.

The elevator car 2 is suspended by suspension element 4 that is connected between the balance weight 2e and the elevator car 2. The suspension element 4 can be a single member or a bunch of similar parallel members, for instance suspension ropes. In this embodiment the suspension ratio of the sus pension element 4 is 2:1. In that case the first ends of the suspension element 4 are secured at their first fastening point 4c, for example at the top part of the guide rail 3, from which the suspension element 4 is led downwards to go under and around a diverting pulley 2f in connection with the balance weight 2e. From the diverting pulley 2f the sus pension element 4 is led upwards to go over and around a di verting pulley 4a that is fitted with bearings on its shaft, for instance at the upper part of the guide rail 3. From the diverting pulley 4a the suspension element 4 descends down wards to go under and around diverting pulleys 5 at the bot tom of the elevator car 2 and from the diverting pulleys 5 the suspension element 4 is led upwards to its second fas tening point 4b where the second end of the suspension ele ment 4 is secured, for example at the top part of the guide rail 3. The elevator car 2 is also equipped with safety gear system that is arranged to stop the movement of the elevator car 2 and to lock the elevator car 2 into the guide rails 2 when needed. Thanks to the suspension like this the roof 2a of the elevator car 2 can be openable. Each floor has a landing door le that is presented in figure 1 seen from the direction of the elevator shaft lc. In addi tion the elevator comprises at least an operating system, a control system, an electrical system, a variety of sensor arrangements and a safety system comprising an inspection mode, which inspection mode is here a common term for the operation mode which is activated when performing inspec tion, maintenance or repair work or other operations that require a safe working environment.

Figure 2 presents in a simplified and diagrammatic back view the upper part of the elevator shaft lc in the building 1 according to figure 1. Also, in this figure the back wall of the elevator shaft lc is removed and the elevator shaft lc is seen from its backside. In the situation of figure 2 the elevator car 2 is in its uppermost floor lb in the top part of the elevator shaft lc. The top clearance between the roof 2a of the elevator car 2 and the ceiling Id of the elevator shaft lc is at its minimum.

Figure 3 presents in a simplified and diagrammatic back view the upper part of the elevator shaft lc in the building 1 according to figure 1 in the situation where the maintenance or repair task is in progress. The openable roof 2a of the elevator car 2 is opened in this embodiment by sliding the first part 10a of the roof, for example the upper part, onto top of the second part, for example the lower part, and a maintenance hole or opening covering substantially a half of the area of the roof 2a is created through the roof 2a. The elevator car 2 has been run with a service run or inspection run in an appropriate location in the elevator shaft lc so that the working person being inside the elevator car 2 has an easy access to the elevator components and appliances in the elevator shaft lc. In this case the required safety space is created at least partly inside the elevator car 2.

Figures 4-6 present in a simplified and diagrammatic oblique top view an upper part of the elevator car 2 according to the invention. The elevator car 2 comprises at least a roof 2a, two sidewalls 2b, a back wall 2c, a front wall 2d having an opening for a car door, and a floor. Figures 4 and 5 pre sent the upper part of the elevator car 2 vertically cross- sectioned just behind the front wall 2d and seen towards the back wall 2c of the elevator car 2. In figure 4 the roof 2a is closed and in figure 5 a half of the roof 2a is opened comprising a manhole 13 or clearance for maintenance work. Figure 6 presents an upper part of the elevator car 2 seen from behind and a half of the roof 2a opened for maintenance work .

In an advantageous embodiment presented in figures 4-6 the roof 2a of the elevator car 2 comprises two plate-like roof elements, the first roof element 10a and the second roof el ement 10b. The roof elements 10a, 10b can be substantially similar, and each roof element 10a, 10b covers substantially half an area of the roof 2a of the elevator car 2.

The upper edge of the elevator car 2 comprises a guide rail assembly 12 that has guide rails on which the roof elements 10a, 10b are mounted for sliding the roof elements 10a, 10b in a horizontal direction. Preferably, the guide rail assem bly 12 is mounted onto all of the walls 2b, 2c and 2d of the elevator car 2, and comprises two layers of the guide rails one layer on top the other. The first roof element 10a or the uppermost roof element is fitted on the uppermost layer of guide rails and the second roof element 10b or the lower most roof element is fitted on the lowermost layer of guide rails so that the first roof element 10a can be slid onto the second roof element 10b or the second roof element 10b can be slid under the first roof element 10a. In order to lock the roof elements 10a, 10b in their loca tions the arrangement according to the invention comprises a locking adjustment that has a locking element 11 that is ad vantageously a plate-like element. The locking element 11 is preferably fastened to the roof elements 10a, 10b under the roof elements 10a, 10b. However, the locking element 11 can have its own guide rails to keep the locking element 11 in its location.

An important objective of the present invention is to make it possible to create the manhole 13 or clearance through the roof 2a of the elevator car 2 in order to facilitate a safe maintenance work in the elevator shaft lc from inside the elevator car 2. The manhole 13 can preferably be done by sliding the first roof element 10a onto the second roof ele ment 10b, or by sliding the second roof element 10b under the first roof element 10a. However, the roof elements 10a, 10b must be locked from sliding during normal use. Advanta geously, the locking is made with the dedicated locking ele- ment 11 of the locking adjustment.

Figures 7-12 present in a simplified and diagrammatic front view different kinds of car roof structures according to the invention. Figures 7 and 8 present the structure where the locking element 11 comprises two adjacent parts 11a and lib, which have a different thickness or in practice height. The first part 11a is thicker than the second part lib so that a locking shoulder 11c is formed between the two parts 11a, lib. When the locking element 11 is in its working location the upper surface of the second part lib is lower than the upper surface of the first part 11a so that the locking shoulder 11c is substantially vertical and the height of the locking shoulder 11c is substantially equal to the thickness of the second roof element 10b that is the lowermost roof element and is placed, when the roof 2a is closed, just upon the second part lib of the locking element 11, as is presented in figure 7. In that case the second roof element 10b cannot move horizontally. At the same time the first roof element 10a is on the first part 11a of the locking element 11. Preferably, the first roof element 10a is fastened, for ex ample, into the guide rail assembly 12 by fastening ele- ments.

The length of the parts 11a, lib and also the length of the locking element 11 is substantially equal to the length of the roof elements 10a, 10b. The width of the second part lib of the locking element 11 is substantially equal to the width of the second roof element 10b. In this case the length is measured in the depth direction of the elevator car 2 and the width is measured in the width direction of the elevator car 2.

The longitudinal locking shoulder 11c is arranged to lock the second roof element 10b in its location so that the sec ond roof element 10b cannot slide horizontally and thus form an aperture to the roof 2a of the elevator car 2.

The lower surface lid of the locking element 11 can be sub stantially even and continuous. Thus, when the locking ele ment 11 covers substantially the entire inner cross-section of the elevator car 2 it can also be used as a decorative element where the lower surface is decorated in a wanted way. Thus, the lower surface of the locking element 11 forms the ceiling of the elevator car 2.

Figures 9 and 10 present in a simplified and diagrammatic front view another advantageous car roof structure according to the invention. Figure 9 presents the roof structure com pleted as it is in a normal use, and figure 10 presents the locking element 11 separated from the roof elements 10a, 10b.

In this embodiment the locking element 11 is only under the first roof element 10a and covers the horizontal distance between the second roof element 10b and the side wall 2b of the elevator car 2, which side wall 2b is adjacent to the first roof element 10a. Thus, the width of the locking ele ment 11 is now substantially a half of the width of roof 2a of the elevator car 2. In this embodiment the roof elements 10a, 10b are mounted on the guide assembly 12 and can be slid along the guide rail assembly 12 in the same way as in the embodiment according to figures 7 and 8. The locking el ement 11 can be fastened with fastening elements, such as screws or alike, to the first roof element 10a just above the locking element 11.

The lower surface lid of the locking element 11 can be sub stantially even and continuous, and substantially similar to the lower surface lOd of the second roof element 10b that is the lowermost roof element. Thus, when the locking element 11 covers substantially the half of the inner cross-section of the elevator car 2, and as much as the first roof element 10a, the locking element 11 can also here be used as a deco rative element where its lower surface lid is decorated in the same way as the lower surface lOd of the second roof el- ement 10b. Thus, the lower surface lOd of the second rood element 10b and the lower surface lid of the locking element 11 form together the ceiling of the elevator car 2.

Figures 11 and 12 present in a simplified and diagrammatic front view yet another advantageous car roof structure ac cording to the invention. Figure 11 presents the roof 2a in a situation of a normal use when the car roof 2a is closed, and figure 12 presents the roof 2a opened for maintenance work through the manhole 13.

For the sake of clarity, in figure 11 only the guide rails of the guide rail assembly 12 on both side walls of the ele vator car are presented, and behind the roof 2a only a short part of the guide rail assembly 12 on the back wall of the elevator car is presented in the middle of the roof 2a, and the guide rail assembly 12 on the front wall of the elevator car is totally removed. In figure 12 the guide rail of the guide rail assembly 12 behind the roof 2a is presented long er than in figure 11 and only a short part neat the right most guide rail of the guide rail assembly 12 is missing to make the profile of the rightmost guide rail of the guide rail assembly 12 on the sidewall clearer. The walls of the elevator car 2 are not presented in figure 12.

In this embodiment the roof elements 10a, 10b themselves form a locking arrangement to each other. Preferably, the cross-sectional profile of the guide rails of the guide rail assembly 12 is now a rectangular C-profile where the guide rails comprise a horizontal upper flange, a horizontal lower flange and a vertical connection flange to join the horizon tal flanges together. Advantageously, the roof elements 10a, 10b are lying on the lower flange of the rails of the guide rail assembly 12 at the same level of height end-to-end each other .

Both the roof elements 10a, 10b are of the same height or thickness and the inner height of the guide rails in the guide rail assembly 12 is suitably greater than the combined height of the roof elements 10a, 10b. That makes it possible to have a short vertical gap between the lower second roof element 10b and the upper first roof element 10a when the roof elements are slid one upon the other. Preferably, the gap is formed with sliding elements that are placed onto the upper surface of at least one of the roof elements 10a, 10b. Advantageously, the sliding elements are placed onto the two end edges of the selected roof element 10a or 10b inside the cross-sectional area of each guide rail of the guide rail assembly 12 on those walls where the ends of the roof ele ments 10a, 10b are. For example, in this embodiment those walls are the back wall 2c and the front wall 2d of the ele vator car 2. The sliding element can be any suitable element that makes the sliding possible and maintain a short verti cal gap between the roof elements 10a, 10b in order to pre vent lower surface of the roof element 10a or 10b that is slid onto the other from damaging by the dirt on the upper surface of the other roof element.

Also, the similar sliding elements can be placed onto the upper surface of both the roof elements 10a, 10b. In that case it does not matter which roof element is slid onto which when the manhole 13 is created.

During normal use the vertical movement of the roof elements 10a, 10b is blocked by blocking elements 14 that are placed between the upper surface of the roof elements 10a, 10b and the upper flange of the rails of the guide rail assembly 12. When the manhole 13 is created the blocking elements 14 are removed and one of the roof elements 10a, 10b is lifted up wards and slid along the guide rails and the sliding ele ments on the upper surface of the other roof element onto the other roof element. It is also possible to do so that one of the roof elements 10a, 10b is lifted upwards and the other roof element is slid along the guide rails under the lifted roof element.

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 of the elevator car and the locking element for locking the parts of the roof can be different from what is presented above.

It is also obvious to the person skilled in the art that the roof elements can also be more than two. Large elevator cars can, for instance have three or four roof elements. In addi tion the roof elements can be similar to each other or their shape and size can differ from each other. Essential is that there is some kind of a locking and filling element that prevents horizontal movements of the roof elements during the normal use of the elevator.

It is also obvious to the person skilled in the art that in stead of sliding the roof elements in the width direction of the elevator car the structure of the roof elements and locking element can also be such that the roof elements are slid in the depth direction of the elevator car.

It is further obvious to the person skilled in the art that the suspension and/or traction ratio of the elevator car can be different from what is presented above. The suspension and/or traction ratio can be, for instance 1:1, the suspen sion ratio can also be 2:1 but the traction ratio 1:1. How ever, it is essential that the elevator structure is such that the roof of the elevator car can be easily opened.

It is yet further obvious to the person skilled in the art that the suspension and traction arrangement of the elevator car can be different from what is presented above. The loca tion of the hoisting machinery can also be in the upper part of the elevator shaft, and the suspension and traction of the elevator car can be carried out in different ways, for instance with common hoisting ropes that suspend the eleva tor car and the balance weight and also moves them.