Background of the invention

The invention relates to an elevator comprising an elevator shaft with a pit with limited depth .

The invention further relates to a method for executing maintenance measures for an elevator where an elevator pit is with limited depth .

The field of the invention is defined more speci fically in the preambles of the independent claims .

An elevator comprises an elevator car which is moved vertically in an elevator shaft and is stopped at landings . A bottom of the elevator shaft comprises a pit . There is a desire to decrease depths of the pits since deep pits cause several problems to building structure and cause expenses for builders . However, reduced depth of the pit needs to be considered by elevator manufactures since safety regulations require that risk of crushing must be prevented in situations when the elevator car is moved to its lowermost position . Since there is a need for maintenance , at least for some extend, in every pit , di f ferent solutions have been designed by the elevator manufactures for executing the needed maintenance measures . However, the known solutions have shown to contain some disadvantages .

Brief description of the invention

An obj ect of the invention is to provide a novel and improved elevator with a pit with limited depth . A further obj ect is to provide a new and improved method for executing maintenance measures for a pit of an elevator shaft .

The elevator according to the invention is characteri zed by the characteri zing features of the independent apparatus claim . The method according to the invention is characteri zed by the characteri zing features of the independent method claim .

An idea of the disclosed solution i s that the elevator comprises at least one pit extension space next to the pit . The pit extension space is located below the lowermost landing and is provided with an openable and closable hatch thereby allowing maintenance technicians to enter to the pit extension space from the lowermost landing . The pit extension space is in hori zontal connection to the pit via a narrow gap whereby at least visual inspection of the pit can be done from the extension space without entering to the pit . In other words , the pit extension space provides good visibility to the pit through the narrow open gap .

An advantage of the disclosed solution is that required visual inspections can be done quickly and easily from the pit extension space remotely . The remote inspection is safe and the solution is simple and fully mechanical fail proof solution . The system works even without any electrical power or electrical control system making solution inherently safe . Further, the solution enables to perform pit maintenance i . e . , inspection and service , from outside the shaft and disables need to open car flooring, a car wall , or a hatch on the car wall for maintaining the pit . Then the structure of the flooring of the elevator car may be simpler .

According to an embodiment , the elevator comprises technical devices and elements at the pit and they need to be at least inspected time to time , or in accordance with planned maintenance schedules . At least some of these technical devices and elements may also require regular maintenance measures such as adj ustments , greasing and component changes . Examples of such technical devices and elements are an elevator car buf fer, a sheave , a counterweight buf fer, limit switches , rope tension switches and possible other sensors and electronic devices . Now it is possible to visually check operating condition of these elements from the pit extension space remotely . The remote inspection i s also very useful when examining failure causes in fault situations of the elevator .

According to an embodiment , the maintenance measures after the visual inspection may include at least removal of foreign matter remotely from the pit without entering the pit . In other words , maintenance technicians can at first inspect i f there is dirt , waste , dust , sand, water, or lost items in the pit , and if so, they can thereafter execute required cleaning by removing the foreign matter using sucking actions i . e . , by vacuuming and pumping executed remotely from the lowermost landing .

According to an embodiment , hoses or tubes of vacuuming and pumping devices can be led to the pit through the narrow opening or gap between the pit and the pit extension space . Thus , cleaning work can be done quickly and properly .

According to an embodiment , the maintenance measures after the visual inspection may include adj ustments of technical devices or elements , as well as changes of components or entire devices . These measures may be executed remotely from the pit extension space without entering to the pit .

According to an embodiment , a bottom of the pit extension space is on the same level as a bottom of the pit . Then maintenance operations are facilitated and good visibility to targets to be inspected is possible .

According to an embodiment , depth of the pit below the lowermost landing is 500 mm or les s . Thi s kind of elevators may be called as low pit elevators .

According to an embodiment , vertical height of the narrow gap between the pit and the pit extension space is 300 mm or less . In other words , the height of the narrow gap is selected so that maintenance technicians are not able to enter from the pit extension space to the pit through the gap . The narrow gap provides the maintenance technicians visibility to the pit and allow use of tools and other equipment remotely from the pit extension space .

According to an embodiment , vertical height of the narrow gap is 200 - 300 mm .

According to an embodiment , the height of the narrow gap is limited by a vertically movable limiting element vertical position of which is adj ustable by means of at least one adj usting element .

According to an embodiment , the limiting element is a hori zontal beam or hori zontal structure located under a door sill of the lowermost landing . Height position of the limiting element can be adj usted by means of one or more adj usting screws . Alternative adj usting elements , such as wedges and eccentric pieces , may also be utili zed .

According to an embodiment , the hatch of the pit extension space is provided with at least one access control device being in connection to an access control system of the elevator whereby the elevator is configured to be connected from a normal operation mode to a maintenance mode in response to opening of the hatch . In other words , opening of the hatch switches the maintenance mode on and prevents normal operation thereafter . Then the elevator is controlled by the maintenance technicians only and safe operation at the pit is possible . Excess of unauthori zed people to the pit extension space is prevented and safety for the maintenance technicians executing their maintenance operation i s ensured .

According to an embodiment , the hatch may be provided with at least one electrical lock and opening of the lock is signaled to the access control system. There may be a code key lock system, for example .

According to an embodiment , the hatch may be provided with at least one mechanical lock and there may be one or more sensing devices , or sensors , for sensing movement of the hatch . Sensing data of the sensing devices is signaled to the access control system or to a safety circuit .

According to an embodiment , the hatch is provided with hinges and can be turned in relation to the hinges to a vertical or substantially vertical open position and to a horizontal closed position . The hinges may be arranged to an edge closest to a door opening . Then the hatch may be in its open position alongside doors of an entrance of the door opening and thereby the hatch does not form any obstacle for the maintenance technicians operating on the lowermost landing .

According to an embodiment , the hatch is provided with a sliding mechanism for opening and closing it . Then the hatch can be moved aside in lateral direction and moved back after the maintenance operation is completed .

According to an embodiment , the hatch is designed to be removed from a surface of the lowermost landing for opening an access to the pit extension space . The detached hatch is remounted after the maintenance operation is completed .

According to an embodiment , the pit extension space and the hatch are in front of a door opening at the lowermost landing . In other words , the hatch locates in front of an elevator landing door on the area, which is reserved for entering to the elevator .

According to an embodiment , the lowermost landing may comprise two door openings for a through type elevator car . Then there are two door openings on opposite sides o f the elevator i . e . , on so called A and C sides . In this case there may be the pit extension space and the hatch in front of one of these opposite door openings , or alternatively, at both door openings . In other words , the pit may be in hori zontal connection to one or two pit extension spaces .

According to an embodiment , the elevator car comprises an apron device provided with at least one vertically orientated protective element for preventing falling into the elevator shaft from the landings . Further, the protective element has a collapsible structure whereby height o f the protective element is configured to decrease when lower end of the protective faces an obstacle . In other words , the apron device is of collapsible type and does not inj ure arms of the maintenance technician even in situation when the elevator car moves downwards during the maintenance operation .

According to an embodiment , the elevator comprises an apron stopper device which is configured to move below vertical movement path of the protective element of the apron device in response to opening of the hatch of the pit extension space , whereby movement of the lower end of the protective element for decreasing the narrow gap between the pit and the pit extension space in prevented . In other words , there is an automatically operating device for ensuring that the protective element of the apron device will not decrease the connection between the pit and the pit extension space i f the elevator car is for some reason moved downwards during the maintenance operation .

According to an embodiment , the apron stopper device may comprise a hori zontally movable slide element which i s connected to the hatch by means of a lever mechanism . The lever mechanism transmits force to the slide element for moving it to a stoppage position and to an idle position .

According to an embodiment , the apron stopper device may comprise a manually movable element arranged transverse to the movement path of the apron device . Then the maintenance technician may connect the stopper on and of f .

According to an embodiment , the pit is provided with at least one buf fer which is supported on a hori zontally movable structure whereby the buf fer is movable from the pit to the pit extension space . In other words , the buf fer can be moved aside from the pit for the duration of the maintenance operations so that needed inspections , component changes and other maintenance operations for the buf fer can be done in the pit extension space . Thereafter, the buf fer can be moved back to the pit . The inspections and change of buf fers can be done without entering to the pit .

According to an embodiment , the buf fer is mounted to a support element which is slidable in relation to a base element mounted fixedly to a bottom of the pit . Thus , there is a sliding support for the buf fer . There may be guide surfaces between the support element and the base element so that the movement of the buf fer is controlled .

According to an embodiment , the buf fer is mounted to a support element provided with rolling elements .

According to an embodiment , the buf fer can be moved manually between the operational position and the maintenance position by means of the maintenance technicians .

According to an embodiment , the buf fer arrangement may comprise moving means for facilitating the moving of the buf fer . The moving means may comprise a gripping element extending close to the pit extension space so that it is easy to grip by the maintenance technician . Alternatively, there may be a cable or belt system for executing the movement . A further poss ibility is that there is a link mechanism for transmitting movement for the buf fer .

According to an embodiment , the buf fer may be locked to the operational position by means of screw mounting means , or alternatively there may be quick coupling means .

According to an embodiment , the elevator is provided with a rescue moving system for moving the elevator car from outside the elevator shaft without entering to the pit . And further, the rescue moving system is provided with a transmission system for transmitting moving force generated at the pit extension space to the elevator car or to a counterweight assembly of the elevator . In other words , the elevator car is movable forcedly by the rescue moving system in s ituations when the elevator is without electricity and when the elevator car is in a so called balanced situation when it does not move under influence of the gravity after manual opening of brakes of the elevator car . The elevator car can be moved without a need to have an access on top of the elevator car or to the pit . The solution provides a safe and handy arrangement for performing rescue and entrapment in such special balanced situations .

According to an embodiment, the elevator is a traction elevator comprising a counterweight assembly . The rescue moving system comprises at least one bendable element , such as a belt , strip, or rope , for coupling lower part of the elevator car and the counterweight assembly together . The rescue moving system further comprises at least one pulley mounted to the pit and the bendable element is running via the pulley . The pulley is configured to be rotated by means of the force generated externally at the pit extension space . The pulley can be rotated to pull the elevator car downwards , or the pulley can be rotated to pull the counterweight assembly downwards causing thereby the elevator car to move upwards . There may be several alternative ways to rotate the pulley from the pit extension space .

According to an embodiment , the rescue moving system comprises : at least one bendable transmission element , such as a rope or belt , coupled to the elevator car, at least one pulley supported on the pit, and a shaft selectively connectable to the pulley for transmitting rotation torque generated at the pit extension space to the pulley and further via the bendable transmission element to the elevator car .

According to an embodiment , the shaft may be supported to the pit and may comprise a coupling end facing away from the pit ( towards a pit extension space ) . Then a ratchet tool or a power screwdriver can be connected to the shaft for providing the required torque .

According to an embodiment , there may be a coupling mechanism for selecting when the shaft is coupled to the pulley and when it is in its normal idle position . The coupling mechanism may comprise a gear cog at a first end of the shaft and a spring for forcing the shaft away from a gearing of a pul ley i . e . , towards the idle position . The shaft can be pushed axially against force of the spring for coupling the gears and for thereby setting the coupl ing mechanism to rescue position . The shaft needs to be pushed axially while directing the torque . When the needed elevator car movement has been reached then the shaft is left to be returned automatically by the spring forces to the idle position .

According to an embodiment , the disclosed solution relates to a method for executing maintenance operation for an elevator comprising an elevator shaft with a pit and wherein the method comprises : executing visual inspection for the pit ; and executing maintenance measures for the pit in response to the detected need based on the visual inspection; executing the maintenance measures for the pit with limited depth . The method further comprises entering from a lowermost landing via an openable and closable hatch to a pit extension space being below the lowermost landing and in hori zontal connection with the pit ; and executing at least the visual inspection from the pit extension space without entering to the pit .

According to an embodiment , the method further comprises preventing entering of maintenance technicians from the pit extension space to the pit by means of a narrow gap with vertically limited height .

According to an embodiment , the method further comprises executing cleaning of the pit and removal of foreign matter remotely from the pit extension space without entering the pit .

According to an embodiment , the method further comprises connecting the elevator automatically out of a normal operation mode to a maintenance mode in response to detected opening of the hatch . According to an embodiment, the method further comprises arranging the hatch on the first landing in front of a door opening of the elevator car.

According to an embodiment, the method further comprises moving the elevator car in upward direction to a maintenance position wherein a bottom of the elevator car is above level of the first landing. In other words, the elevator car is moved upwards to provide the pit more vertical space for facilitating the maintenance operation.

Additional solutions - two auxiliary inventions This document discloses following two auxiliary solutions which may not be in accordance with the present solution claimed in independent claims. However, these auxiliary inventions may comprise same additional features and embodiments disclosed above in this document.

A first auxiliary invention:

A buffer assembly of an elevator, wherein the buffer assembly comprises at least one buffer and mounting means for fastening the buffer assembly to a pit of a shaft of the elevator; char ac t e r i z e d in that the mounting means comprise at least one horizontally movable structure whereby the buffer is movable out of the pit in lateral direction for executing maintenance operation .

In other words, the buffer assembly can be loosened or detached and then pulled to service area into the pit extension space.

According to a lift directive, the elevators are required to be equipped with buffers under the elevator cars. As safety components, these buffers are required to be inspected periodically. For that there is a special buffer fixing system enabling to inspect buffers and replace buffers when needed from the pit extension space serving as an area for inspection and service.

In this system the buffer and a buffer fixing plate may be fixed to a bar (e.g., a flat bar) which can slide along a railing profile (e.g., a C-rail profile) . Then whole buffer assembly can be loosened or detached (e.g., screw or bolt connection) and pulled to the service area at the pit extension space.

A second auxiliary invention:

A rescue moving system for moving an elevator car of an elevator in an elevator shaft without use of a hoisting machinery of the elevator; char ac t e r i z e d in that the rescue moving system comprises a transmission system for transmitting moving force from a location external to the elevator shaft and without entering to a shaft pit .

In other words, the rescue moving system is to perform car movement for rescue and entrapment without entering to the pit. The solution is especially for performing rescue and entrapment in low pit and no head room elevator (e.g. in balanced situation) with a rescue rope or belt system which provides means to move the car from outside of the shaft so that a maintenance technician is working from the service area, such as at a pit extension space. The apparatus is independently operable since it does not require electric energy from a power supply network and is not based on the hoisting machinery of the elevator.

The above disclosed embodiments may be combined to form suitable solutions having those of the above features that are needed.

Brief description of the figures

Some embodiments are described in more detail in the accompanying drawings, in which Figure 1 is a schematic and highly simpli f ied side view of a traction elevator,

Figure 2 is a schematic side view of a lower part of an elevator provided with a pit extension space for executing maintenance measures ,

Figure 3 is a schematic side view of a pit extension space provided with an openable hatch,

Figure 4 is a schematic side view of a pit extension space provided with an apron stopper,

Figure 5 is a schematic side view of a pit provided with a moving mechanism for moving a buf fer in lateral direction to a pit extension space ,

Figures 6 and 7 are schematic views of moving systems of buf fer assemblies seen in direction of trans fer movement ,

Figure 8 is a a schematic diagram of possible features of a buf fer assembly,

Figure 9 is a schematic side view of a rescue movement arrangement for moving an elevator car in a so called balanced situation,

Figure 10 is a schematic side view of a rescue movement arrangement operable from a pit extension space ,

Figure 11 is a schematic side view of a rescue movement arrangement which can be selectively connected on for moving an elevator car,

Figure 12 is a a schematic diagram of possible features of a rescue moving system, and

Figure 13 is a a schematic diagram of some features and steps relating to maintenance operations executed for an elevator with a low pit .

For the sake of clarity, the figures show some embodiments of the disclosed solution in a simpli fied manner . In the figures , like reference numerals identi fy like elements . Detailed description of some embodiments

Figure 1 discloses a traction elevator 1 mounted to an elevator shaft 2 of a building . The elevator 1 comprises an elevator car 3 for receiving load to be transported . The car 3 and a counterweight assembly 4 are suspended from a suspension rope 5 passing via a hoisting machinery 6 . The hoisting machinery 6 comprises a traction sheave 7 driven by means of an electric motor M . Between the suspension rope 5 and the traction sheave 7 occurs friction which is utili zed for transmitting li fting power to the elevator system . The hoisting machinery 6 may comprise one or more additional pulleys 8 for guiding and controlling the suspension rope 5 . The hoisting machinery 6 may be located at an upper machine room 9 , or alternatively the system may be a so called machine room les s elevator . A compensation chain or rope 10 may, or may not , be connected between the counterweight assembly 4 and a bottom of the elevator car 3 .

The elevator car 3 can be driven to desired landings L or f loors under control of one or more control units CU . Below a first or lowermost landing LI there is a pit 11 of the shaft 2 . There may be buf fers 12 in the pit 11 as well as other technical devices . Further, the elevator car 3 i s provided with an apron device Ad below its bottom . The apron device Ad is located at an entrance side of the elevator car 3 where is a door opening 13 . The apron device Ad comprises at least one protective element Be . The protective element Pe extends vertically below the bottom of the elevator car 3 or a door sill 14 . I f the elevator car 3 is stopped to a position shown in Figure 1 , then the apron device 13 closes uncontrolled entry to the elevator shaft 2 .

It should be noted that the type and operating principle of the elevator 1 may be di fferent from the one shown in Figure 1 . Figures show the pit and the lower part of the elevator system in a highly simpli fied manner . In Figure 2 an elevator car 3 has moved to a maintenance position Mp wherein a bottom 15 of the elevator car 3 is above a lowermost landing LI and a protective element Pe closes a gap between the bottom 15 and the lowermost landing LI . There may be a sensing device S for providing sensing data on the position of the elevator car 3 for a control unit . At a front of a door entrance 16 a floor of a lowermost landing LI there is an openable and closable hatch H . Below the hatch H is a pit extension space Es which is thereby located beside a pit 11 and has a passage to the pit 11 through a narrow gap G . Then a maintenance technician Mt can visually check condition of a pit 11 and devices therein . The visual inspection is thereby executed remotely through the narrow gap G . The pit 11 comprises a buf fer 12 and possible other devices which need to be checked and serviced time to time . Height of the narrow gap is limited so that the maintenance technician Mt cannot enter to the pit 11 via the pit extension space Es but has only visibility to the pit 11 and have access for arms and tools through the narrow gap G .

A protective element Pe of an apron device Ad has a collapsible , or telescopic, structure whereby height of the protective element Pe can decrease when lower end of the protective Pe faces an obstacle , such as an arm, i f the elevator car 3 moves downwards during the maintenance measures for some reason .

Figure 3 discloses that a hatch H is located at a door entrance 16 and may be turned T relative to hinges 17 from a closed position to an open position . The hinges 17 may be located close to elevator doors 18 whereby the hatch H may be alongside the elevator doors 18 when it is turned to the open position . The hatch H may comprise a locking system 19 for preventing unauthori zed access to a pit extension space Es . The locking system 19 may comprise a mechanical lock or an electrical lock with access code or opening tag . There may also be one or more sensors 20 or switches for sensing opening of the hatch H . The mentioned locking system 19 and the sensor 20 may be part of an access control device 21 being in communication with an access control system AS and a control unit CU of the elevator . Then, opening of the hatch H is detected and communicated to the access control system AS whereafter the control unit CU connects the elevator from a normal operation mode to a maintenance mode .

A narrow gap G between the pit 11 and the pit extension space Es may be fixed or vertical dimensions of the gap G may be adj ustable . When being adj ustable , there may be a vertically movable limiting element 22 vertical position of which is adj ustable by means of adj usting elements , such as screws . The limiting element 22 may be located under a door sil l 23 or any other suitable fixed structure above the gap G . The limiting element 22 may be a beam, a telescoping expandable structure or any other adj ustable or movable piece , panel , or structure .

Figure 4 discloses that an elevator car 3 may comprise an apron device AD below its bottom 15 and that a protective element Pe of the apron device Ad may have a collapsible structure , which may comprise telescopic or slidable elements , for example . When such collaps ible protective element Pe faces an obstacle , vertical height of the protective element Pe can decrease . The solution may also comprise an apron stopper device 24 which is configured to move below vertical movement path of the protective element Pe of the apron device Ad in response to opening of a hatch H of a pit extension space Es . Then movement of the lower end of the protective element Pe for decreasing the narrow gap G between a pit 11 and the pit extension space Es in prevented . The apron stopper device 24 may comprise a moving stopper element 25 , such as a beam, plate , or panel , which may turn or slide when the hatch H i s turned T to its opened position . In Figure 4 the stopper element 25 is arranged to turn from vertical position to horizontal position when turning force is transmitted to it by means of a bar 26 connected to the hatch H . The stopper element 25 and the bar 26 may be provided with needed j oints or hinges .

Figure 5 discloses that a pit 11 is provided with a buf fer 12 which is supported on a laterally movable structure 27 whereby the buf fer 12 is movable from its operational position at the pit 11 to the pit extension space Es for inspection and other maintenance measures . The buf fer 12 and the laterally movable structure 27 may form a buf fer assembly BA. The buf fer assembly BA can be loosened or detached and then pulled to a service area into the pit extension space Es .

The laterally movable structure 27 may comprise a guide element 28 f ixed on a bottom of the pit 11 and slide element 29 or sledge arranged movably in relation to the guide element 28 . After locking elements 30 , such as screws , are loosened, the slide element 29 can be pulled together with the buf fer 12 to the pit extension space Es of at least closer it . The slide element 29 may be provided with a handle 31 , or corresponding element , for facilitating the trans fer movement .

Figure 6 di scloses a buf fer assembly BA, wherein a buf fer 12 is mounted on a slide element 29 supported on a guide element 28 having a C-profile .

Figure 7 di scloses a buf fer assembly BA, wherein a buf fer 12 is mounted on a carrier element 32 provided with rollers 33 and being supported on a guide element 28 having a U-profile .

In some alternative solutions , the laterally movable structures 27 of the buf fer assemblies BA shown in Figures 5 - 7 may also be modi fied so that the guide elements 28 are left out . Then the slide elements 29 or carrier elements 32 are moved on a bottom surface of the pit 11 and the position of the locking elements 30 and their counter elements arranged on the bottom of the pit 11 of the pit extension space ES define the operational position of the buffer 12 . In other words , fastening of the buf fer assembly BA can be loosened and the buf fer 12 can be pulled freely to the pit extension space for inspection and maintenance . After that , the buf fer assembly BA is pushed back and is positioned to its original operational position and is locked in place .

Figure 8 discloses some features of a buffer assembly BA. The buf fer assembly BA may comprise one or more buf fers 12 for an elevator car and for a counterweight . The buf fer assembly BA further comprises mounting means 34 , such as fastening and locking means , and further one or more hori zontally or laterally movable structures 27 . Then the buf fer assembly BA can be moved 35 out of a pit including moving 36 to a pit extension space or moving 37 to any other space which is located laterally in relation to the pit . A further possibility is to move 38 the buf fers assembly BA inside the pit to a position which is easier to be reached from outside the pit when executing maintenance operations .

Figure 9 discloses a lower part of an elevator 1 provided with a rescue moving system 39 for moving an elevator car 3 from outside an elevator shaft 2 without entering to a pit . The rescue moving system 39 is provided with a transmission system 40 for transmitting moving force generated at a pit extension space Es to the elevator car 3 .

The rescue moving system 39 may comprise at least one bendable transmission element 41 , such as a rope or belt , coupled to the elevator car 3 , at least one pulley 42 supported on the pit , and a shaft 43 selectively connectable to the pulley 42 for transmitting rotation torque generated at the pit extens ion space Es to the pulley 42 and further via the bendable transmission element 41 to the elevator car 3 . In a traction elevator the bendable transmission element 41 is arranged to couple the elevator car 3 and a counterweight 4 . When the counterweight 4 is pulled downwards , the elevator car can be moved upwards towards an upper landing for rescue , alternatively the elevator car 3 is pulled downwards towards a lower landing for rescue . Decision on which one of the elevator car 3 and the counterweigh 4 is pulled downwards is made on position of the elevator car 3 , for example . The force for the pulling can be made by means of normal hand tools 44 .

Figure 10 discloses a transmi ssion system 40 of a rescue moving system 39 and comprises a shaft 43 supported on a floor of pit 11 and may comprise a coupling end 45 facing away from the pit 11 i . e . , towards a pit extension space Es . Then a tool can be connected to the shaft 43 for providing the required torque . An opposite end of the shaft 43 may be provided with a coupl ing mechanism for selectively coupling to a gear 46 or directly to transmission elements of a pulley 42 . The coupling mechanism is normally in an idle position .

Figure 11 discloses that a coupling mechanism o f a shaft 43 of a rescue moving system 39 may comprise a gear cog 47 at a first end of the shaft 43 and a spring 48 for forcing the shaft 43 away from a gear 46 of a pulley 42 i . e . , towards the idle position . The shaft 43 can be pushed axially against force of the spring 48 for coupling the gears and for thereby setting the coupling mechanism to rescue position . The shaft 43 needs to be pushed axially while directing the torque . When the needed movement for an elevator car has been reached, then the shaft 43 is returned automatical ly by the spring forces to the idle position . A ratchet tool or a power screwdriver 49 can be connected to a coupling end 45 of the shaft 43 .

Figure 12 discloses some features of a rescue moving system 39 . The system comprises a transmission system 40 which is operable from a location external to a pit and does not implement normal hoisting machinery of an elevator . The transmission system comprises 40 comprises a bendable transmission element 41 , such as a belt or rope . Needed torque for the transmission system 40 is generated by means of portable hand tools 50 , such as manual tools or battery drive hand tools . The disclosed system can be uti li zed for moving the elevator car 51 from a balanced situation either upwards or downwards depending on the location the elevator car in relation to landings .

Figure 13 discloses some features that maintenance operation 52 for a low pit may comprise . An elevator may be connected to a maintenance mode 53 and an elevator car may then be moved 54 to a maintenance position above a lowermost landing . Maintenance technicians are located 55 on a lowermost landing and they can open 56 a hatch of a pit extension space and can thereafter enter 57 the space at least partly . The maintenance technicians can execute visual inspection 58 for the pit . There is visibility 59 through a gap to the pit and the maintenance technicians determine 60 need for actual maintenance tasks . I f something needs to be done , these further measures 61 can be done through the gap . Arms and tools can penetrate 62 through the gap to the pit . Possible foreign matter is removed 63 from the pit by vacuuming, pumping, or picking with suitable tools . It is also possible to execute 64 other maintenance measures remotely, such as adj ustments and simpler component changes . In more complicated matters , the maintenance technicians may move 65 components from the pit to the pit extension space or closer to it . There may be moving elements 66 for facilitating trans fer of the components . After all the maintenance measures are completed 67 the hatch can be closed 68 and the elevator can be connected 69 to a normal operating mode .

Implementation of the disclosed solution and embodiments are not limited to the exemplary elevator di sclosed in the Figures . The solution can be used when executing maintenance for any type of elevator with the low pit e . g . , an elevator compri sing a machine room or lacking a machine room, an elevator comprising a counterweight or lacking a counterweight . Thus , the disclosed solution can be implemented in a versatile manner in buildings with low pit . The drawings and the related description are only intended to illustrate the idea of the invention . In its details , the invention may vary within the scope of the claims .