ELEVATOR ARRANGEMENT WITH LOW HEADROOM

Abstract

The invention relates to an elevator arrangement comprising an elevator with an elevator a control system, a safety system and an inspection or maintenance mode, which 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 a roof. The roof of the elevator car is arranged to open outwards from the elevator car in order to form a natural safe space inside the elevator car at least during inspection and maintenance tasks.

Description

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

This invention relates particularly 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 elevator car is at its uppermost position. In an advantageous solution 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.

Many kinds of tasks, such as tests, 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.

Standards such as EN81 require certain minimum safety distances between elevator car and the top and the bottom of the elevator shaft to provide a person a safe working space when he/she is accessing to the machines and shaft components. A particular aspect is to provide safety spaces, which could be called also refuge spaces. A safety space or refuge space is kept free from any equipment so that a person could fit into it. A safety space is a natural one if suitable clearance is available without shortening the stroke of the elevator car. In some cases natural safe working spaces are not possible to provide, because the elevator shaft is not tall enough and thus there is no room in the elevator shaft above the topmost position of the elevator car and/or below the lowest position of the elevator car. In such cases artificial safety spaces can be created. The artificial safety space creation requires additional equipment, such as brakes or movable buffers, and particular safety considerations.

Usually the maintenance work is done on the roof of the elevator car. In that case, when working on the roof of the elevator car an unintentional movement of the elevator car must be prevented in some other way than by the regular operating brakes of the elevator. It is known in the prior art that this kind of prevention can be done by locking the elevator 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 working 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 adequate safety space in the upper part of an elevator shaft is to use one or more turnable buffers that are disposed below 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 before 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 position 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 activation 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 supervision 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 elevator 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 though 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.

When making maintenance work the elevator is set to the maintenance mode which prevents the normal use of the elevator and, for instance, calling the elevator car from landing floors. Also landing doors cannot be open and an access to the elevator shaft is prevented. However, in that case landing doors can be opened by a special key, for instance with a so-called triangle key. This brings out a new problem because those special keys are easily available. In that case unauthorized persons can acquire that kind of special key and open the landing doors of the elevator shafts for their own purposes. This increases risks of accidents. Another problem is that mechanic solutions to open the landing doors increase the costs of the elevator and also cause visual problems in the door area of elevators because additional holes must be done into doors in every floor.

One objective of the present invention is to eliminate drawbacks of prior art technology and 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. 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 safety arrangement that is operationally extremely reliable, easy and fast to use, and that immediately prevents the movement of the elevator car if somebody steps onto the roof of the elevator car. Yet another objective of the present invention is to achieve an elevator arrangement where there is no need to open landing doors for doing maintenance work of the elevator appliances in the elevator shaft.

The elevator arrangement according to the invention is characterized by what is disclosed in the characterization part of 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 roof of the elevator car is opened for creating a safe working space inside the elevator car for maintenance work and for enabling the elevator shaft maintenance work and also maintenance of equipment located adjacent to the elevator car top.

In order to achieve the objectives mentioned above, the present invention provides an elevator arrangement comprising an elevator with an elevator a control system, a safety system and an inspection or maintenance mode, which 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 a roof. Advantageously the roof of the elevator car is arranged to open outwards from the elevator car in order to form a natural safe space inside the elevator car at least during inspection and maintenance tasks.

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 of the solution according to the invention is that a movement of the elevator car can be effectively, reliably and safely prevented if somebody steps onto the roof of the elevator car or there is more weight than a predetermined value allows on the elevator car.

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 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. Yet a further advantage is that uplifted roof protects the working person in the elevator car from possible falling objects in the elevator shaft.

Yet another advantage of the solution according to the invention is that there is no need to open the landing doors for maintenance purposes and therefore the special key to open the landing doors are not needed. That also effectively prevents an authorized access onto the roof of the elevator car.

Also the there is no need to make holes in the door leaves for the special keys, and no need to arrange complex special opening mechanism in the doors. That makes the outward appearance of the landing doors look better and prevents unauthorized persons to open the landing doors with special keys they have copied or acquired without authorizing license.

In the following, the invention will be described in detail by the aid of example embodiments by referring to the attached 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 according 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 building according to FIG. 1,

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

FIG. 4 presents in a simplified and diagrammatic side view an upper part of the elevator car according to the invention in a situation where the roof of the elevator car has been opened for maintenance work,

FIG. 5 presents in a simplified and diagrammatic back view an upper part of the elevator car according to FIG. 4 when the roof of the elevator car is lifted upwards,

FIG. 6 presents in a simplified and diagrammatic side view an upper part of the elevator car according to another advantageous embodiment of the invention in a situation where the roof of the elevator car has been opened for maintenance work,

FIG. 7 presents in a simplified and diagrammatic top view the elevator car according to FIG. 6 cross-sectioned along the line A-A in FIG. 6, in the situation where the roof of the elevator car is lifted upwards,

FIG. 8 presents in a simplified and diagrammatic enlarged view an upper corner of the elevator car according to FIG. 5 when the roof is in its closed position,

FIG. 9 presents in a simplified and diagrammatic side view an upper part of the elevator car according to another embodiment of the invention when the roof is partially open for maintenance work,

FIG. 10 presents in a simplified and diagrammatic side view an upper part of the elevator car according to yet another embodiment of the invention when the roof is open for maintenance work, and

FIG. 11 presents in a simplified and diagrammatic side view an upper part of the elevator car according to yet another embodiment of the invention when the roof is open for maintenance work.

An aspect of the invention is to achieve an elevator arrangement with an elevator car having an easily openable roof which makes it possible 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 reduces the height of the shaft needed.

FIG. 1 presents in a simplified and diagrammatic back view a part of the building 1 where the back wall of the elevator shaft 1c is removed, and an elevator in the elevator shaft 1c, in which elevator the solution according to the invention can be used. The building 1 has a roof 1a just above the elevator shaft 1c and four floors 1b served by the elevator.

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 1c along guide rails 3, and a counterweight or balance weight 2b that is also arranged to run up and down in the elevator shaft 1c along its guide rails which are not presented in FIG. 1 for the sake of clarity. Later in this connection only balance weight 2b 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 headroom above the elevator car 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 1c, below the elevator car 2 and advantageously below the first floor level 1b.

A traction member 6 is connected between the balance weight 2b 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 1c. From the first fastening point 9 the traction member 6 is led upwards to go over and around a traction sheave 2e in connection with the balance weight 2b and from the traction sheave 2e 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 1c, 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 1c.

The elevator car 2 is suspended by suspension element 4 that is connected between the balance weight 2b 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 suspension 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 2d in connection with the balance weight 2b. From the diverting pulley 2d the suspension element 4 is led upwards to go over and around a diverting 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 downwards to go under and around diverting pulleys 5 at the bottom of the elevator car 2 and from the diverting pulleys 5 is led upwards to its second fastening point 4b where the second end of the suspension element 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 1e that is presented in FIG. 1 seen from the direction of the elevator shaft 1c. In addition 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 inspection, test, maintenance or repair work or other operations that require a safe working environment.

FIG. 2 presents in a simplified and diagrammatic back view the upper part of the elevator shaft 1c in the building 1 according to FIG. 1. Also in this figure the back wall of the elevator shaft 1c is removed and the elevator shaft 1c is seen from its backside. In the situation of FIG. 2 the elevator car 2 is in its uppermost floor 1b in the top part of the elevator shaft 1c. The top clearance between the roof 2a of the elevator car 2 and the ceiling 1d of the elevator shaft 1c is at its minimum. In that solution the height of the elevator shaft 1c is equal to the total height of the floors 1b of the building 1 or even less than the total height of the floors 1b of the building 1. In that case the elevator shaft 1c can be totally inside the building 1.

FIG. 3 presents in a simplified and diagrammatic back view the upper part of the elevator shaft 1c in the building 1 according to FIG. 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 lifting it upwards in this embodiment, and a maintenance hole or opening is created between the uplifted roof 2a and the upper edges of the elevator car 2. The elevator car 2 has been run with a service run or inspection run in an appropriate location in the elevator shaft 1c 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. In this case the required safety space is created at least partly inside the elevator car 2. The uplifted roof 2a protects the working person also from falling tools and other objects that may fall down into the elevator shaft 1c from other working sites above, for instance from a top part of a neighboring elevator shaft where another elevator is installed at the same time.

FIGS. 4-8 present in a simplified and diagrammatic view, an upper part of the elevator car 2 according to the invention. In FIGS. 4 and 5 the roof 2a is open for a maintenance or repair work and a created manhole or opening 2b on top of the elevator car 2 makes it possible to reach the elevator appliances or components in the elevator shaft 1c from inside the elevator car 2. In FIG. 5 the back walls of the elevator shaft 1c and the elevator car 2 are removed and the elevator shaft 1c and elevator car 2 are seen from their backside.

In the embodiment of FIGS. 3-8 the roof 2a is openable by lifting it straight upwards. For that purpose the elevator comprises opening means 10 that are arranged to open and close the roof 2a when the elevator is switched on to a safe inspection or maintenance mode, later in a shorter way referred only as “inspection mode”. The moving of the roof 2a can be carried out in several ways. One way is to use articulated arms 11 and one or more actuators to turn the articulated arms 11. In this embodiment four articulated arms 11 are used, two pieces on each side of the elevator car 2. The articulated arms 11 help to lift and lower the roof 2a. The actuators to lift and lower the roof 2a are not presented in the FIGS. 3-5 and 8, but they can be, for instance, gas springs, screws driven by a crank or electric motor, springs associated with dampening gas springs, or the roof 2a can be even moved manually by pushing the roof 2a upwards and pulling it downwards. When lifting and lowering the roof 2a manually gas springs can be used to ease the lifting and to dampen the movement of the roof 2a when closing it so that the roof 2a does not unwantedly hit the upper edges of the elevator car 2.

An advantageous embodiment of the invention presented in FIGS. 6 and 7 comprises a linear actuator 10a in two opposite upper corners of the elevator car 2 in order to move the roof 2a up and down. The other two opposite upper corners comprise a telescopic guide element 11a in each corner. The linear actuators 10a such as spindle motors have been synchronized together and arranged to move the roof 2a of the elevator car 2 linearly and smoothly up and down and the telescopic guide elements 11a have been arranged to keep the movement of the roof 2a linear. The linear actuators 10a and the telescopic guide elements 11a have been fastened, for example at their lower ends to the outer upper part of the side walls of the elevator car 2, and at their upper ends to the roof 2a of the elevator car 2. The power for the linear actuators 10a can be taken from portable batteries or from the mains supply.

Instead of using spindle motors as linear actuators 10a simple screws or motion screws or also pneumatic cylinders can be used as linear actuators 10a together with the telescopic guide elements 11a to move the roof 2a of the elevator car 2 up and down. When using screws they can be rotated manually with a crank or for instance with a cordless electric driver or drill.

When using pneumatic cylinders they are operated with a portable air pump, and the power for the pump is taken either from the elevator arrangement or from the mains supply of the building. If needed the roof 2a can be also moved by using a manual pump or battery driven portable pump, for instance during a power failure.

The air supply coupler of the pump can advantageously be placed in the same place with the electric appliances of the elevator car 2. The pneumatic cylinders can easily be synchronized with each other to make the cylinders move the lightweight roof 2a smoothly up and down. Another advantage is that when using pneumatic cylinders as linear actuators 10a a separate limit switch is not needed because the lifting movement comes to a stop when the pneumatic cylinders have extended to their longest position. Yet another advantage is that the roof 2a needs not a complex locking system in its lowermost position because the internal suction of the cylinders prevents the lifting of the roof 2a if the air is not pumped into the cylinders. All the same advantages mentioned above apply also to spindle motors.

FIG. 8 presents in an enlarged side view an upper corner of the elevator car 2 according to FIG. 5 when the roof 2a is in its closed position. The closed position here means that the roof 2a has been lowered to its lowermost position.

The elevator also comprises supporting elements 2e on the upper edges of the elevator car 2, which supporting elements 2e are arranged to support the descended roof 2a so that there is a narrow gap 2d for ventilation between the roof 2a and the upper edges of the elevator car 2. The support element 2e can be a gas spring or a fuse-like element that is arranged to support the roof 2a as long as a predetermined threshold value of the force directed towards the roof 2a does not exceed. For instance, if the threshold value is set to 25 kg, the elevator works as normal until something heavier than 25 kg is placed onto the roof 2a of the elevator car 2. In that case the support of the supporting elements 2e yields and the roof 2a descends slightly downwards and triggers the safety control switches 12 that are situated between the roof 2a and the upper edges of the elevator car 2.

The elevator comprises a safety arrangement that is connected to the control system of the elevator. The safety control switches 12 belong to the safety system of the elevator safety arrangement and are arranged to cut the safety circuit of the elevator when a weight greater than the predetermined threshold value is on the roof 2a of the elevator car 2, for instance if a human being steps onto the roof 2a. The cutting of the safety circuit prevents elevator car 2 from moving away from its position as long as the elevator safety system is again reset by an authorized person. This improves the safety of the elevator and makes it possible to use the roof 2a of the elevator car 2 as a working platform, if needed.

FIGS. 5 and 8 also present corner casings 13 that are fastened at the upper corners inside the elevator car 2. The elevator car 2 may comprise one or more corner casings 13 at the upper corners of the interior of the elevator car 2. The corner casings 13 may comprise car lighting and other electrical appliances, and also apertures for elevator car ventilation. The corner casings 13 may comprise also inspection mode buttons 13a to run the elevator car 2 in the inspection mode. The buttons 13a are in safe under a lid 13b that can be opened only by an authorized person and after the elevator has switched to the inspection mode.

In additions the corner casings 13 may comprise a control unit for the spindle motors mentioned above or the air supply coupler of the pump for the pneumatic cylinders as mentioned above. One of the corner casings 13 may also comprise a control panel with buttons to run the elevator in the inspection mode and to stop the movement of the elevator car 2 if needed.

FIG. 9 presents in a simplified and diagrammatic side view an upper part of the elevator car 2 according to another embodiment of the invention when the roof 2a is partially open for a maintenance or repair work. In this embodiment the roof 2a is a flexible door comprising narrow slats, which are connected to each other in a way that they can make a part of the roof 2a bend downwards at the upper corner of the elevator car 2 when the roof 2a is opening and sliding away from the top of the manhole or opening 2b. The safety arrangement of the elevator of this type with safety control switches 12 and supporting elements 2e can be essentially similar to what is described above.

FIG. 10 presents in a simplified and diagrammatic side view an upper part of the elevator car 2 according to yet another embodiment of the invention when the roof 2a is open for maintenance or repair work. In this embodiment the roof 2a consists of two halves that are hinged with a hinge 2c at their first ends at the upper part of the sidewalls of the elevator car 2 in the middle area of the elevator car 2. Thus the halves of the roof 2a are closing towards the front edge and back edge of the elevator car 2 and opening towards the center of the elevator car 2. This gives more space for maintenance work in the backside of the elevator car 2 and in the front side of the elevator car 2 where, for example the door machinery is.

FIG. 11 presents in a simplified and diagrammatic side view an upper part of the elevator car 2 according to yet another embodiment of the invention when the roof 2a is open for maintenance or repair work. In this embodiment the roof 2a also consists of two halves that are hinged with a hinge 2c at their first ends at the upper part of the sidewalls of the elevator car 2. In this case the hinge points are close the front wall and back wall of the elevator car 2. In this case the halves of the roof 2a are closing towards the center of the elevator car 2 and opening towards the front edge and back edge of the elevator car 2. This gives more space for maintenance work in the sides of the elevator car 2 where, for example the guide rails are.

According to the invention the elevator car 2 has roof 2a that can be lifted upwards to create an access for maintenance purposes to the elevator appliances in the elevator shaft 1c and to elevator components at the upper part of the elevator car 2. The person performing maintenance tasks can stand in a good position on a special portable working surface that is placed inside the elevator car 2, and has an access to all the components that need maintenance. During the maintenance tasks the interior of the elevator car 2 is in this case a natural safe space according to the elevator regulations. In addition the uppermost position of the uplifted roof 2a is arranged so that the cap between the roof 2a and the upper edges of the elevator car 2 is so small that the maintenance person cannot climb out from the elevator car 2 into the elevator shaft 1c and step onto the roof 2a. The walls of the elevator car 2 have been arranged to act as railings for the maintenance person.

One more safety appliance is a safety net that is fastened between the upwards moving roof 2a and the upper edges of the elevator car 2 if the cap between the wall of the elevator car 2 and the wall of the elevator shaft is more than a predetermined distance, for instance more the 300 mm. The net effectively prevents the maintenance person from falling into the elevator shaft 1c.

The elevator arrangement also comprises a mechanical upper safety means to prevent the elevator car to collide the ceiling 1d of the elevator shaft 1c when the inspection mode is witched on. The upper safety means is operatively connected to bi-directional safety brakes fastened to the elevator car 2.

It is obvious to the person skilled in the art that the invention 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 mechanisms for opening and closing the roof can be different from what is presented above.

It is also 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 suspension ratio can also be 2:1 but the traction ratio 1:1. However, it is essential that the elevator structure is such that the roof of the elevator car can be easily opened.

It is 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 location 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 elevator car and the balance weight and also moves them.

Claims

1. Elevator arrangement comprising an elevator with an elevator control system, a safety system and an inspection or maintenance mode, which 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 a roof, wherein the roof of the elevator car is arranged to open outwards from the elevator car, a natural safe working space is provided for conducting inspection and maintenance tasks from inside the elevator car to the elevator shaft and a refuge space is provided inside the elevator car.

2. Elevator arrangement according to claim 1, wherein the walls of the elevator car are arranged to act as railings for the maintenance person.

3. Elevator arrangement according to claim 1, wherein the elevator arrangement comprises a mechanical upper safety means to prevent the elevator car to collide the ceiling of the elevator shaft when the inspection mode or maintenance mode is witched on, and that the upper safety means is operatively connected to bi-directional safety brakes of the elevator car.

4. Elevator arrangement according to claim 1, wherein the elevator car comprises at least one corner casing fastened at the upper corner inside the elevator car which corner casing comprises inspection mode or maintenance mode buttons to run the elevator car in the inspection or maintenance mode, and that the maintenance control unit is under the roof of the elevator car which the roof is arranged to open an access to the maintenance control unit.

5. Elevator arrangement according to claim 1, wherein the elevator arrangement comprises opening means that are enabled to open and close the roof only when the elevator is switched on to the inspection or maintenance mode.

6. Elevator arrangement according to claim 1, wherein the opening means are arranged to open and close the roof essentially in a vertical direction.

7. Elevator arrangement according to claim 5, wherein the arrangement the opening means comprises linear actuators to move the roof up and down.

8. Elevator arrangement according to claim 7, wherein one linear actuator is placed in two opposite upper corners of the elevator car, and that the other two opposite upper corners comprise a telescopic guide element in each corner.

9. Elevator arrangement according to claim 7, wherein the linear actuator is one of the following: a spindle motor, a pneumatic cylinder, a screw or a motion screw driven by a crank or electric motor, a gas spring, a spring mechanism associated with a dampening gas spring.

10. Elevator arrangement according to claim 1, wherein the arrangement comprises a safety net between the roof and the upper edges of the elevator car if the cap between the wall of the elevator car and the wall of the elevator shaft is more than a predetermined distance.

11. Elevator arrangement according to claim 1, wherein the opening means are arranged to open and close the roof essentially in a horizontal direction.

12. Elevator arrangement according to claim 1, wherein the roof comprises two essentially similar halves, that are hinged at the upper part of the elevator car essentially in the central area of the elevator car, and that the opening means are arranged to open and close the halves of the roof turning the halves around the hinges towards the center line of the elevator car when opening the halves and towards the front and back walls of the elevator car when closing the halves.

13. Elevator arrangement according to claim 1, wherein the roof comprises two essentially similar halves, that are hinged at the upper part of the elevator car close to the front and back wall of the elevator car, and that the opening means are arranged to open and close the halves of the roof turning the halves around the hinges towards front and back walls of the elevator car when opening the halves and towards the center line of the elevator car when closing the halves.

14. Elevator arrangement according to claim 1, wherein the elevator comprises a safety system that is arranged to prevent the elevator car from moving if a weight on the roof of the elevator car exceeds a predetermined threshold value, which safety system comprises support elements on the top edges of the elevator car to support the roof when the roof is closed, and which support elements are arranged to yield under the roof if a weight on the roof exceeds a predetermined threshold value.

15. Elevator arrangement according to claim 14, wherein the safety system of the elevator comprises one or more safety control switches on the top edges of the elevator car to trigger the safety circuit off in order to prevent the elevator car from moving when the support elements have yielded and let the roof descend downwards, and that the safety system of the elevator is arranged to prevent the elevator car from moving after the triggering of the safety control switches as long as the elevator safety system is again reset.

16. Elevator arrangement according to claim 1, wherein the height of the elevator shaft is equal to the total height of the floors of the building or less than the total height of the floors of the building 1.