The present invention relates to an elevator as defined in the preamble of claim 1 and an elevator car roof railing as defined in the preamble of claim 6.

This invention relates particularly to an elevator where a headroom is low. The headroom in this context means the distance between the floor of the topmost floor and the ceiling of the elevator shaft. 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. Various tasks, such as tests, inspections, adjustment works, maintenance or repairs, later referred in a shorter way only as "maintenance work", are often performed in the elevator shaft. Usually the maintenance work is done on the roof of the elevator car. In that case the safety of the persons performing the tasks mentioned above has always to be secured. One way to secure the safety of the persons performing the tasks on the roof of the elevator car is to equip the roof with a railing that act as a safety railing that prevents the persons falling down from the roof the elevator car.

Conventionally the railings are fastened firmly in their position and the height of the railing cannot be adjusted after the fastening. In elevators with a low headroom fitted railings may cause problems when the elevator car is driven to its uppermost position at the upper part of the elevator shaft. For instance, different structures, such as a shaft top beam with diverting pulleys for suspension ropes or belts of the elevator car may extend so down that the rail- mg hits to it when the elevator car is driven to its uppermost position that is, for example, somewhat higher than the normal position on the top floor. Also a lifting hook or a suspension loop in the ceiling of the elevator shaft may cause the same kinds of problems.

The problem has tried to solve, for instance, by hinging the railing so that it can be toppled down when the elevator car is driven to its uppermost position. Or the railings are toppled down during the normal use of the elevator and lifted up during maintenance works. Also telescopic railings are used but in these structures the height adjustment must be done manually.

The solutions mentioned above are, however, complicated and in many cases difficult to carry out. In addition, it may happen that the railing is forgotten to its toppled down position or manually lowered position. In these cases the safety of the persons performing the tasks on the roof of the elevator car is reduced. The same applies with the railings that can be taken away from their locations for the time when the elevator car is intentionally driven to its uppermost position.

One objective of the present invention is to eliminate drawbacks of prior art technology and to achieve an elevator and an elevator car roof railing where the headroom at the upper part of the elevator shaft can be as low as possible, and the railing does not prevent the elevator car running as up as possible. Another objective of the present invention is to improve safety at work by preventing the hands of maintenance persons to hurt between the firmly fixed railing and the fixed structures at the upper part of the elevator shaft . The elevator according to the invention is characterized by what is disclosed in the characterization part of claim 1. Correspondingly the elevator car roof railing according to the invention is characterized by what is disclosed in the characterization part of claim 6. 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 mentioned above, the present invention provides an elevator comprising an elevator car moving along a vertical path in an elevator shaft, the elevator car equipped with a railing extending upwards from the roof of the elevator car, and which elevator comprises a structural part attached to the elevator shaft above the elevator car and extending downwards to a lower position than the highest position reached by the railing. Advantageously the railing comprises one or more yielding sections located under the structural part and arranged to yield downwards. Advantageously the yielding section, or at least a part of it, is arranged to yield towards the roof of the elevator car .

One advantage of the invention is that firmly fixed static railings can be used also in those elevators where the headroom is low and insufficient. Another advantage is that the structure of the railing according to the invention is reliable and simple compared to the railings of prior art mentioned above. Yet another advantage of the solution according to the invention is that thanks to the yielding section of the top edge of the railing the hands of the maintenance persons are in better safe. This improves the safety at work .

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 with the elevator car in the building according to Fig. 1,

Fig. 3 presents in a simplified and diagrammatic side view the upper part of the elevator shaft with the elevator car in the building according to Fig. 1,

Fig. 4 presents in a simplified and diagrammatic side view an upper part of the elevator car according to the invention with a railing in a situation where the yielding section of the railing is in its uppermost position, and Fig. 5 presents m a simplified and diagrammatic side view an upper part of the elevator car according to the invention with the railing in a situation where the yielding section of the railing is in its lowermost position .

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 invention can be used. The building 1 has a roof la just above the elevator shaft lc and four floors lb served by the elevator .

The elevator comprises among other things an elevator car 2 supported by a sling 9. The 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 5 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 balance weight 5 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 lc, below the elevator car 2 and advantageously below the first floor level lb. A traction member 6 is connected between the balance weight 5 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 1:1. In that case the first end of the traction member 6 is secured at its first fastening point, for example at the bottom part of the elevator car 2. From the first fastening point the traction member 6 is led downwards to go under and around the drive wheel 7 of the hoisting machinery 8 at the bottom part of the elevator shaft lc, from where the traction member 6 is led to go under and around a diverting pulley 6a from where the traction member 6 continues upwards to its second fastening point, for example at the lower part of the balance weight 5.

The elevator car 2 is suspended by suspension element 4 that is connected between the balance weight 5 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 1:1. In that case the first ends of the suspension element 4 are secured at their first fastening point, for example at the top part of the elevator car 2, from which the suspension element 4 is led upwards to go over and around a diverting pulleys 4a that are situated, for instance in the shaft top beam 3a at the upper part of the elevator shaft lc. From the diverting pulley 4a the sus- pension element 4 descends downwards to the balance weight 5 where the second ends of the suspension element 4 are secured at their second fastening point, for example at the upper part of the balance weight 5. Figure 2 presents in a simplified and diagrammatic back view the upper part of the elevator shaft lc with the elevator car 2 in the building according to figure 1, and figure 3 presents in a simplified and diagrammatic side view the upper part of the elevator shaft lc with the elevator car 2 in the building according to figure 1. In figures 2 and 3 the elevator car 2 is in its uppermost position. For safety reasons the elevator car comprises a railing structure 2a at the edges of the roof of the elevator car 2. The railing structure 2a acts as a safety railing. The railing 2a extends upwards from the roof. In this kind of elevator structure the shaft top beam 3a acting as a structural part at the upper part of the elevator shaft lc extends so down that it would collide the railing when the elevator goes to its uppermost position if the railing were a normal fixed height railing. In the elevator according to the invention the railing 2a comprises a downward yielding section 12 at least in one of its four skeleton frames. Preferably the yielding section 12 is situated in all necessary locations in any of the skeleton frames, for example in two opposite skeleton frames of the railing 2a, like in the embodiment example. According to an advantageous embodiment of the invention the yielding section 12, or at least a part of it, yields towards the roof of the elevator car 2 after hitting to the shaft top beam 3a or the structural part or another obstacle. Yielding here means that at least the upper part of the yielding section 12 moves towards the roof of the elevator car 2.

Figures 4 and 5 present in a side view the railing 2a according to the invention in a more detailed way. The walls of the railing 2a are preferably skeleton frames comprising a group of vertical bars 10 and a group of horizontal bars 11, 11a. The horizontal bars 11, 11a are fastened fixedly at their height levels. Thus, the height of the upper surface of the horizontal bars 11, 11a from the roof of the elevator car is static. The upper horizontal bars 11 form a part of the upper edge of the railing 2a whose distance to the roof of the car 2 is static, and said upper edge is arranged to extend higher than the lowest point of the structural part 3a when the elevator car 2 is reaching the uppermost position of its trajectory. The upper horizontal bars 11 that form the upper edge of the railing 2a can be of different length. For instance, in figures 4 and 5 in the wall where the yielding section 12 is, the upper edge of the railing 2a is formed of two static horizontal bars 11 and one vertically movable horizontal bar 12a that belong to the yielding section 12. The length of each static horizontal bar 11 is only a part of the whole length of the upper edge of the railing 2a. Whereas the length of the static horizontal bars 11 in the adjacent sides can be as long as the whole sidewall.

The downward yielding section 12 is situated in the middle of the upper part of the skeleton frame so that when the elevator car 2 rises upwards and the upper surface or edge of the downward yielding section 12 hits an obstacle, for in- stance, the shaft top beam 3a the downward yielding section 12 presses downwards and makes room for the elevator car 2 to rise. In this embodiment example there are two downward yielding sections 12, one in each opposite sidewalls of the railing 2a, whereas the other two opposite sidewalls of the railing 2a have no downward yielding sections 12. However, the number and position of the downward yielding sections 12 can vary depending the elevator structure and the obstacles at the top part of the elevator shaft lc. The railing 2a may comprise, for instance only one, two or three downward yielding sections 12, or four downward yielding sections 12, one in each wall of the railing 2a, or even more, if needed.

It is essential that each downward yielding section 12 is directly under the obstacle it is intended for. In other words, each yielding section 12 is situated under the obstacle, such as the structural part 3a, substantially in the same vertical line or plane with the obstacle. To be more precise, each yielding section 12 is situated in the trajec- tory line of the elevator car 2 between the roof of the elevator car 2 and the obstacle, such as the structural part 3a.

The downward yielding section 12 comprises the vertically movable substantially horizontal bar 12a, as mentioned above, a static horizontal bar 12c and a damping mechanism 12b, such as a spring system between the movable bar 12a and the static bar 12c. In addition, the downward yielding section 12 comprises vertical guide rails 13 affecting at each end of the movable horizontal bar 12a.

The movable horizontal bar 12a of the downward yielding section 12 is the upper bar and is fitted in between the fixedly fastened static upper horizontal bars 11 so that its up- per surface is in its normal position on the same height level as the upper surface of the static upper horizontal bars 11. The ends of the movable horizontal bar 12a are fitted to run along the guide rails 13 when the movable horizontal bar 12a moves up and down.

Correspondingly the static horizontal bar 12c of the downward yielding section 12 is the lower bar and is fastened fixedly at its location below the movable horizontal bar 12a. The damping mechanism 12b between the movable horizon- tal bar 12a and the static horizontal bar 12c comprises, for example, two springs which press shorter when the movable horizontal bar 12a moves downwards towards the roof of the elevator car 2 and so makes the downward movement of the movable horizontal bar 12a possible and at the same time dampen the movement. The dampening force of the springs or spring force of the damping mechanism 12b is selected so that the movable horizontal bar 12a does not yield towards the roof of the elevator car 2 too easily but gives suffi- cient support if somebody unintentionally leans towards the movable horizontal bar 12a. However, the spring force of the damping mechanism 12b is at the same time selected so that a hand or other part of a human body that is pressed between the obstacle, such as the structural part 3a and the movable horizontal bar 12a will not be injured.

In figure 4 the movable horizontal bar 12a is in its normal position and in figure 5 the movable horizontal bar 12a is in its lowermost position in the situation when the elevator car 2 is in its uppermost position. However, the shaft top beam or other possible obstacle that has pressed the movable horizontal bar 12a down, is not presented in figure 5 for the sake of clarity. 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 structure of the railing 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 2:1. It is further obvious to the person skilled m 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 move them up and down.

It is still further obvious to the person skilled in the art that the damping mechanism between the movable horizontal bar and the second horizontal bar of the downward yielding section may not necessarily comprise mechanical spring elements but can also comprise gas springs or other suitable damping elements.