BACKGROUND

The invention relates to an elevator comprising an elevator shaft provided with landing doors .

Elevators having a low pit , i . e . the bottom of the shaft are more and more popular, since lowering the pit lowers also capital expenditure of the elevator . The pit in this context means the clearance between the bottom of the elevator car and the floor of the elevator shaft in the situation when the elevator car is positioned at the lowest landing . However, of ficial regulation, such as EU li ft directive , requires that there is a natural safety space at the bottom of the shaft even in a fault situation where the elevator car drops on buf fers the bottom of the shaft . The modes required by the natural safety space are : 400x500x2000mm or alternatively 500x700x1000 mm . Therefore , the pit height is problematic to lower further .

BRIEF DESCRIPTION

Viewed from a first aspect , there can be provided an elevator comprising an elevator shaft provided with landing doors , comprising the lowest of the landing doors being attached to a landing door rack, the lowest landing door and the landing door rack constituting a landing door package , the landing door package being arranged movable on guide elements , the landing door package being movable under control of said guide elements from a normal position where the lowest landing door is serving as an access to an elevator car to a maintenance position where the landing door package lies inside the elevator shaft , providing thus a maintenance space at the bottom of the elevator shaft , the maintenance space being accessible through an opening from where the lowest landing door has moved away . Thereby an elevator having very low or even absent pit but still providing required natural safety space under the elevator car may be achieved .

The elevator is characterised by what is stated in the independent claims . Some other embodiments are characteri sed by what is stated in the other claims . Inventive embodiments are also disclosed in the speci fication and drawings of this patent application . The inventive content of the patent application may also be defined in other ways than defined in the following claims . The inventive content may also be formed of several separate inventions , especially i f the invention is examined in the light of expressed or implicit sub-tas ks or in view o f obtained benef its or benefit groups . Some of the definitions contained in the following claims may then be unnecessary in view of the separate inventive ideas . Features of the di f ferent embodiments of the invention may, within the scope of the basic inventive idea, be applied to other embodiments .

Various embodiments of the first aspect may comprise at least one feature from the following paragraphs :

In one embodiment , the landing door rack comprises an upper hori zontal support arranged in hori zontal plane above and parallel with the lowest landing door, and a lower hori zontal support arranged in hori zontal plane below and parallel with the lowest landing door .

An advantage is that such a structural stability and strength may be achieved in the landing door rack that there is no need for strengthening the lowest landing door, but instead the lowest landing door may have an equal structure with landing doors arranged in upper parts of the elevator . In one embodiment , the upper hori zontal support comprises at least one buf fer arranged for contacting the bottom of the elevator car .

An advantage is contacts between the landing door package in its maintenance position and the elevator car can be cushioned and thus their structures protected .

In one embodiment , the landing door rack comprises a at least one vertical support on both lateral sides of the landing door rack .

An advantage is that such a structural stability and strength may be achieved in the landing door rack that there is no need for strengthening the lowest landing door, but instead the lowest landing door may have an equal structure with landing doors arranged in upper parts of the elevator .

In one embodiment , the landing door package comprises at least one door leaf , the s ill , the top track of the lowest landing door, and optionally an actuator for moving the door leaf .

An advantage is that all said maj or components of the landing door structure may be moved together in group, which makes it simpler to move the package .

In one embodiment , the guide element comprises at least one of the following : a rail , a roller or a slide .

An advantage is that the movement of the landing door package may be reali zed in a simple , reliable and a smooth way with less friction as possible . In one embodiment , the landing door package in its maintenance position is arranged to serve as a safety screen between the maintenance space and the space reserved for a counterweight .

An advantage is that the safety of personnel working in the maintenance space may be improved also in fault situation where the counterweight drops uncontrollably on its buf fer .

In one embodiment , the elevator comprises guide rails for guiding the elevator car, and wherein the landing door package in its maintenance position i s located at a vertical plane next to the plane of the guide rails .

An advantage is that the safety of personnel working in the maintenance space may be improved also in fault situation where the counterweight drops uncontrollably on its buf fer, since the landing door package prevents the personnel ' s access to the space where the counterweight is moving .

In one embodiment , the elevator comprises a safety control system, wherein the landing door package is connected with said safety control system so that the presence of the landing door package in the normal position and in the maintenance position is sensed .

An advantage is that a reliable control over the position of the landing door package may be achieved . Thus , for instance , i f the landing door package is not in the normal position, normal use of the elevator can be prevented . BRIEF DESCRIPTION OF FIGURES

Some embodiments illustrating the present disclosure are described in more detail in the attached drawings , in which

Figure 1 is a schematic side view of a lower part of an elevator in partial cross-section,

Figure 2 is another schematic side view of the lower part of the elevator shown in Figure 1 ,

Figure 3 is a schematic view of another elevator in partial cross-section, and

Figure 4 is another schematic view of the elevator shown in Figure 3 .

In the figures , some embodiments are shown simpli fied for the sake of clarity . Similar parts are marked with the same reference numbers in the figures .

DETAILED DESCRIPTION

Figure 1 is a schematic side view of a lower part of an elevator in partial cross-section, and Figure 2 is another schematic side view of said lower part .

The elevator 100 comprises an elevator shaft 1 that is provided with landing doors 2 , 2a . The lowest 2a of said landing doors is attached or arranged to a landing door rack 3 such that said lowest landing door 2a and the landing door rack 3 constitutes a landing door package 4 . The structures of the rack and the package are illustrated more detailed in connection with the following Figures . The landing door package 4 - and thus the lowest landing door 2a - is arranged movable on guide elements 5 . In one embodiment , such as shown in Figures 1 and 2 , the landing door package 4 is movable in hori zontal direction . In another embodiment , the landing door package 4 is movable in an oblique direction so that the landing door package 4 raises when moved from the normal position towards the maintenance position . In still another embodiment , the landing door package 4 is movable in an oblique direction so that the landing door package 4 falls when moved from the normal position towards the maintenance position .

In one embodiment , the landing door package 4 is moved manually without help of any actuator or power unit . In one embodiment , the landing door package 4 is provided with an actuator or power unit 27 that is arranged to create the force needed for moving the landing door package 4 .

The landing door package 4 is movable under control of said guide elements 5 from a normal position to a maintenance position . In the normal position ( shown in Figure 1 ) the lowest landing door 2a is serving as an access to an elevator car 6 . In the maintenance pos ition ( shown in Figure 2 ) the landing door package 4 lies inside the elevator shaft 1 and provides or creates a maintenance space 7 at the bottom of the elevator shaft 1 . In one embodiment , such as shown in Figures 1 and 2 , the maintenance space 7 is connected or integrated with a pit 26 that lies on the bottom of the elevator shaft 1 . In the maintenance position there is an access A for e . g . maintenance personnel to and away from the maintenance space 7 through an opening 8 of the elevator shaft 1 from where the lowest landing door 2a has been moved away . Various tasks , such as inspections , adj ustment works , maintenance or repairs , shortly "maintenance work" , can be performed in the maintenance space 7 . The maintenance work may be focused to the pit , to the bottom of the elevator car, and/or to the lowest landing door, for instance .

In one embodiment , the landing door package 4 in its maintenance position serve as a safety screen between the maintenance space 7 and a space 21 where a counterweight (not shown) may move .

The elevator is provided with a safety control system 22 , such as a safety circuit . In one embodiment , the landing door package 4 is connected with said safety control system 22 so that the presence of the landing door package 4 in the normal position and in the maintenance position is sensed . This may be reali zed e . g . by closing the safety circuit when the landing door package 4 is in the normal position or in the maintenance position . I f the landing door package 4 is somewhere between said positions , the safety circuit is open .

Typically, the landing door 2 , 2a does not have an actuator of its own . The landing door is opened and closed together with the elevator car door (not shown) so that the movements of the latter are transmitted to the landing door . However, i f the lowest landing door 2a comprises an actuator 17 for moving the door leaf of the lowest landing door open and close , said actuator may be included in the landing door package 4 .

In one embodiment , the landing door package 4 is locked by at least one lock in its normal position, such as shown in Figure 1 . When the elevator car 6 is moved above the lowest landing, such as shown in Figure 2 , the lock ( s ) is/are opened and then the landing door package 4 can be pushed inside the elevator shaft in the maintenance position . Then, personnel have an access in the maintenance space 7 . Following the personnel have left the maintenance space 7 , the landing door package 4 is pulled back to its normal location and the elevator may normally serve the floors .

In one embodiment , the at least one lock is operated by a triangle key . In one embodiment , operation of the at least one lock is based on a digital key that may be combined with a mechanical or an electromechanical key . In one embodiment , the at least one lock is an electrically operated lock, the use of which preferably requires authentication of the user .

Figure 3 is a schematic view of another elevator in partial cross-section, and Figure 4 is another schematic view of the elevator shown in Figure 3 .

The landing door rack 3 is possible to be constructed many ways . In one embodiment , it comprises at least one upper hori zontal support 9 that is arranged in hori zontal plane above and parallel with the lowest landing door 2a, at least one lower hori zontal support 10 arranged in another hori zontal plane below and parallel with the lowest landing door 2a, and at least one vertical support 13 on both lateral sides of the landing door rack . The embodiment shown in Figures 3 and 4 comprises two vertical supports 13 on both lateral sides of the landing door rack . Said supports may be constructed from e . g . a metal profile , and fixed to each other e . g . by welding or fixing means , such as bolts or rivets .

In one embodiment , the upper hori zontal support 9 comprises at least one buf fer 11 that is arranged for contacting the bottom ( or the sling) of the elevator car 6 in case the latter descends on the landing door rack 3 when the landing door rack 3 is arranged to the maintenance position. The embodiment shown in Figures 3 and 4 comprises two cylindrically shaped buffers 11, but it is clear that their number and shape may vary.

In one embodiment, the elevator car 6 comprises at least one lower buffer 12 (shown in Figure 2) for contacting the landing door rack 3 that is arranged to its the maintenance position. In one embodiment, both the landing door rack 3 and the elevator car 6 comprise at least one buffer. Said buffers may be positioned so that they meet as the elevator car contacts the landing door rack, but this is not necessary.

The buffers are preferably elastic and made e.g. of suitable elastomer material.

In one embodiment, the landing door package 4 comprises door leaf (s) 14 of the lowest landing door 2a, as well as the sill 15 and the top track 16 of said lowest landing door. The structure of said door leaf (s) , sill and top track is preferably equal or similar with those in other landing doors arranged in the elevator shaft 1. in other words, the landing door package and the landing door rack do not necessitate any structural or material modifications to be done in the lowest landing door.

In one embodiment, the guide element 5 is attached to a guide rail 20 that is arranged in the elevator shaft 1 for guiding the elevator car 6. One example of this solution is shown in Figures 3 and 4. In one embodiment, the guide element 5 is attached to a guide rail guiding the counterweight (not shown) .

In one embodiment, the guide element 5 is attached to the structure of the elevator shaft 1. For instance, the guide element 5 may be attached to a vertically arranged wall 18 of the elevator shaft or the floor 19 of the elevator shaft, or both the wall and the floor.

In some embodiments of elevators, there are two adjacent elevator shafts without any wall therebetween. Instead, supporting elements, such as supporting beams 23 are arranged between said elevator shafts for supporting thereof and providing points of attachment e.g. for guide rails etc. In one embodiment, the guide element 5 is attached to said supporting element (s) , e.g. to the supporting beam(s) 23, of the elevator shaft.

Typically, the guide element 5 is further attached to the front wall 24 of the elevator shaft.

In one embodiment, the guide element 5 comprises at least one rail. The rail may be arranged to co-operate with one or more roller (s) or slide (s) or rail (s) , for instance, that are attached to the landing door package 4, for instance to the landing door rack 3 thereof.

In one embodiment, the guide element 5 comprises at least one roller. The roller may be arranged to co-operate with one or more rail (s) or slide (s) , for instance, that are attached to the landing door package 4, for instance to the landing door rack 3 thereof.

In one embodiment, the guide element 5 comprises at least one slide. The slide may be arranged to co-operate with one or more rail (s) , roller (s) or slide (s) , for instance, that are attached to the landing door package 4, for instance to the landing door rack 3 thereof.

Typically, the elevator 100 comprises plurality of guide elements 5. For example, the embodiment shown in Figures 3 , 4 comprises four guide elements . It should be noted that all the guide elements may be of similar type and structure . However, this is not always necessary .

The length or extent of the movement from the normal position ( such as shown in Figures 1 and 3 ) to the maintenance position ( such as shown in Figures 2 and 4 , respectively) and back from the maintenance position to the normal position may be selected as needed in boundary conditions set by the structure of the elevator . In one embodiment , such as shown in Figures , the elevator 100 comprises guide rails 20 that are arranged for guiding movements of the elevator car 6 . Said length or extent of the movement is arranged so that the movement of the landing door package 4 stops at a vertical plane 25 next to the plane of the guide rails 20 . This is somewhat less than the distance between the front wall and the back wall of the elevator shaft . In other embodiments , the movement is hal f or more than hal f of said distance between the front and the back walls . In still other embodiments , the movement is substantially less than hal f of said distance between the front and the back walls .

The invention is not limited solely to the embodiments described above , but instead many variations are possible within the scope of the inventive concept defined by the claims below . Within the scope o f the inventive concept the attributes of di f ferent embodiments and applications can be used in conj unction with or replace the attributes of another embodiment or application .

The drawings and the related description are only intended to i llustrate the idea of the invention . The invention may vary in detail within the scope of the inventive idea defined in the following claims . REFERENCE SYMBOLS

1 elevator shaft

2 lowest landing door

3 landing door rack

4 landing door package

5 guide element

6 elevator car

7 maintenance space

8 opening

9 upper hori zontal support

10 lower hori zontal support

11 buf fer

12 bottom of elevator car

13 vertical support

14 door leaf

15 sill

16 top track

17 actuator

18 wall

19 floor

20 guide rail

21 space for counterweight

22 safety control system

23 supporting beam

24 front wall

25 vertical plane

26 pit

27 power unit

100 elevator