Method of maintenance of low pit elevator shaft and elevator

Abstract

A method for executing maintenance operation (18) for an elevator (1) and an elevator. An elevator car comprises an apron device (Ad) with a transparent protective element (Pe). The elevator car is positioned for the maintenance of the pit and related components so that maintenance technicians (Mt) can execute visual inspection (22) of the pit remotely from a lowermost landing (L1). Thus, the inspection requires no entering into the pit.

Description

[0001] Method of maintenance of low pit elevator shaft and elevator

[0002] Background of the invention

[0003] The invention relates to a method for executing maintenance measures for an elevator where an elevator pit is with limited depth .

[0004] The invention further relates to an elevator .

[0005] The field of the invention is defined more speci fically in the preambles of the independent claims .

[0006] 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 .

[0007] Brief description of the invention

[0008] An obj ect of the invention is to provide a novel and improved method for executing maintenance measures for a pit of an elevator shaft . A further obj ect is to provide a new and improved elevator .

[0009] The method according to the invention is characteri zed by the characteri zing features of the independent method claim .

[0010] The elevator according to the invention is characteri zed by the characteri zing features of the independent apparatus claim . An idea of the disclosed solution is that the method is des igned for executing maintenance operation for an elevator comprising an elevator shaft with a pit and an apron device mounted below an elevator car for preventing fall ing into the elevator shaft . The method comprises executing visual inspection for the pit and executing maintenance measures at the pit in response to the detected need based on the visual inspection . Further, the maintenance measures are executed for a shaft wherein the elevator pit is with limited depth . The visual inspection is executed from a lowermost landing of the elevator and through a transparent protective element of an apron device without entering the pit . In other words , the maintenance operation at the pit comprises prior remote inspection from the lowermost landing and may be followed by one or more maintenance measures , task or actions based on detected need for the maintenance .

[0011] An advantage on the disclosed solution is that required visual inspections can be done quickly and easily from the lowermost landing . The remote inspection is safe and the solution does not require extensive modi fications to the structure of the elevator and the building . Further, the disclosed apron device compris ing the transparent element can be implemented in a versatile way in di f ferent elevators and may also be retrofitted to the existing elevators .

[0012] According to an embodiment, depth of the pit is 500 mm or less . In some typical cases , the depth is 300 - 350 mm . Such pits may be called as low pits .

[0013] According to an embodiment , entry to the pit is prevented from the lowermost landing . Thus , there may only be access for tools and other equipment , but the maintenance technicians cannot enter the pit from the first landing .

[0014] 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 a remote position . The remote inspection is also very useful when examining failure causes in fault situations of the elevator .

[0015] According to an embodiment , the method further comprises moving the elevator car for the visual inspection to a first maintenance position wherein a bottom of the elevator car is above the lowermost landing and the transparent protective element of the apron device protects a gap between the lowermost landing and the bottom of the elevator car . In other words , maintenance technicians can inspect in a safely and handy way needs for maintenance actions by utili zing this transparent gap .

[0016] According to an embodiment , height of the transparent gap is 200 - 400 mm . Typical height of the transparent gap is 300 mm . The height of the transparent gap is defined by the protective element of the apron device .

[0017] According to an embodiment , the elevator may be provided with a maintenance mode for facilitating the drive to the first maintenance position . The maintenance mode may comprise automatic drive to the first maintenance position .

[0018] According to an embodiment , the elevator may be provided with at least one first limit switch or sensing device for defining location of the first maintenance position and thereby height o f the gap between the lowermost landing and the bottom of the elevator car .

[0019] According to an embodiment , the method further comprises moving the elevator car after the visual inspection from the first maintenance position in upward direction to a second maintenance position and thereby forming a limited open gap between a lowermost end of the transparent protective element of the apron device and the lowermost landing . Then following one or more additional maintenance tasks can be executed remotely from the lowermost landing and through the open gap for the pit . In other words , maintenance technicians can execute in a safely and handy way needed maintenance actions by utilizing the open gap . The transparent protection element provides visibility to the target and the open gap provides access to the pit for tools and devices operable remotely from the lowermost landing .

[0020] According to an embodiment , the elevator may be provided with a maintenance mode for facilitating the drive to the second maintenance position . The maintenance mode may comprise automatic drive to the second maintenance position .

[0021] According to an embodiment , the elevator may be provided with at least one second limit switch or sens ing device for defining location of the second maintenance position and thereby height of the open gap between the lowermost landing and the bottom of the transparent protective element of the apron device .

[0022] According to an embodiment , height of the open gap is 150 - 200 mm .

[0023] According to an embodiment , the control unit of the elevator may receive sensing data from the drive system and may calculate the mentioned first and second maintenance positions . Then no separate limit switches or sensing devices are necessarily needed .

[0024] According to an embodiment , the solution may comprise an alternative solution wherein the transparent protective element of the apron device may comprise one or more openings or openable portions allowing access through the protective element for the tools or remotely operable devices . According to an embodiment , the maintenance measures after the visual inspection 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 i f 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 .

[0025] According to an embodiment , hoses or tubes of vacuuming and pumping devices can be led to the pit through the open gap . Since the transparent gap provides good visibil ity for the maintenance technicians , cleaning work can be done quickly and properly .

[0026] 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 with special tools and arrangements , or alternatively, maintenance technicians may enter to the pit through an openable floor or floor hatch of the elevator car, or through elevator car wall , or through a hatch in the car wall , and can then make more complicated or extensive tasks therein .

[0027] According to an embodiment , the method comprises executing at least one maintenance task after the visual inspection through an openable floor or floor hatch of the elevator car . The elevator car can be moved to the level of a first landing, or to a desired maintenance position which is located at safe distance from the bottom of the pit . Then the maintenance technicians can enter to the pit or have acces s to the pit by opening the f loor, part of the floor, or the hatch, without danger to fall . Alternatively, the elevator car can be moved so that the maintenance technicians can reach the service targets and execute the measures from the elevator car through the opening on the floor without entering the pit .

[0028] According to an embodiment , the method further comprises providing the apron device with a protective element made of transparent plastic material . In other words , the protective element is made of see-through-plastics . Plastic materials are durable and lightweight .

[0029] According to an embodiment , the protective element is made of polycarbonate sheet .

[0030] According to an embodiment , the protective element is made of acrylic sheet .

[0031] According to an embodiment , the apron device comprises a foldable protective element made of transparent components . The structure may comprise elements movable relative to each other, for example .

[0032] According to an embodiment , the protective element of the apron device comprises several transparent lamellas made of transparent plastic material .

[0033] According to an embodiment , the solution relates to an elevator comprising : an elevator shaft ; an elevator car supported vertically movably inside the elevator shaft ; a hoisting machinery and suspension elements for moving and supporting the elevator car ; several landings ; a pit of the elevator shaft below a lowermost landing; at least one control unit for controlling operation of the elevator ; and wherein the elevator car is provided with an apron device comprising at least one vertically orientated protective element for preventing falling into the elevator shaft . Furthermore , the elevator is a low pit elevator wherein depth of the pit below the lowermost landing is 400 mm or less . The mentioned at least one vertically orientated protective element of the apron device is made of transparent plastic material at least partly . And further, the control unit comprises a maintenance mode for moving the elevator car to a first maintenance position wherein a bottom of the elevator car is located above the lowermost landing and wherein visual inspection o f the pit is executable through the transparent protective element .

[0034] According to an embodiment , the maintenance mode is conf igured to move the elevator car selectively upwards to a second maintenance position wherein an open gap with limited height is formed between the lowermost landing and a lower end of the transparent protective element .

[0035] The above disclosed embodiments may be combined to form suitable solutions having those of the above features that are needed .

[0036] Brief description of the figures

[0037] Some embodiments are described in more detail in the accompanying drawings , in which

[0038] Figure 1 is a schematic and highly simpli f ied side view of a traction elevator,

[0039] Figures 2 and 3 are schematic side views of a lower part of an elevator and maintenance operations executed for a pit of an elevator shaft when an elevator car is at first and second maintenance positions ,

[0040] Figure 4 is a schematic diagram o f possible steps executed during the maintenance operation,

[0041] Figure 5 is a schematic diagram of some features of an apron device , and

[0042] Figure 6 is a schematic diagram of some possibilities to execute maintenance tasks for targets at a pit after visual inspection .

[0043] 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 .

[0044] Detailed description of some embodiments

[0045] 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 .

[0046] 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 . The apron device Ad is in accordance with the embodiments and features disclosed in this document .

[0047] 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 2 and 3 show the pit and the lower part of the elevator system in a highly simpli fied manner .

[0048] In Figure 2 an elevator car 3 has moved to a first maintenance position Mpl 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 low- ermost landing LI . However, there is a transparent gap protection since the protective element Pe of the apron device Ad is made on transparent material . Then a maintenance technician Mt can visually check condition of a pit 11 and devices therein . The visual inspection is executed through a transparent gap . The pit 11 comprises a buf fer 12 and possible other devices which need to be checked and serviced time to time . The elevator car 3 can be driven to the first maintenance position Mpl by means of the control unit CU and there may be a first sensing device S I for providing sensing data on the position of the elevator car 3 .

[0049] In Figure 3 the elevator car is moved further upwards to a second maintenance position Mp2 . There may be a second sensing device S2 for sensing the vertical position of the elevator car 3 . An open gap 16 is formed between a lower end of the protective element Pe and an upper surface of the lowermost landing LI . Tools 17 and other maintenance equipment can be pushed through the open gap 16 to the pit 11 . The maintenance technician Mt has good visibility to the pit 11 through the transparent protective element Pe and the open gap 16 .

[0050] Figure 4 discloses some features that maintenance operation 18 for a low pit may comprise . An elevator may be connected to a maintenance mode 19 and an elevator car may then be moved 20 to a first maintenance position . Maintenance technicians are located 21 on a lowermost landing and they execute visual inspection 22 for the pit . There is visibility 23 through a transparent apron to the pit and the maintenance technicians determine 24 need for actual maintenance tasks . I f something needs to be done , then the elevator car is li fted 25 to a second maintenance position wherein an open gap is formed and good visibility to target is o f fered through the transparent apron and the open gap . Poss ible foreign matter is removed 26 form the pit by vacuuming, pumping, or picking with suitable tools . It is possible to execute 27 other maintenance measures remotely, such as adj ustments and simpler component changes . In more complicated matters , the maintenance technicians may enter 28 the pit via an openable bottom o f the elevator car, or through an openable service hatch . One alternative solution is that the maintenance actions after the inspection measures are done through openable hatches or parts of the floor or wall of the elevator car . When the maintenance operation is completed 29 , then the elevator is connected back 30 to normal operation mode .

[0051] Figure 5 discloses that an apron device Ad comprises one or more protective elements Pe , which at least partly made of transparent plastic material 31 . Two suitable transparent plastic materials are also shown .

[0052] Figure 6 discloses that the mentioned maintenance tasks after the visual inspection can be executed 32 through 33 the elevator car bottom or through 36 the elevator car wall . There may be an openable floor 34 or a floor hatch 35 , or alternatively or in addition to , an openable a wal l panel 37 or a wall hatch 38 . The mentioned openable elements 34 , 35 , 36 , 38 allow entrance to the pit , or access to reach the target located at the pit .

[0053] Implementation of the disclosed solution is not limited to the exemplary elevator disclosed in the Figures . The method can be used when executing maintenance for any type of elevator with an apron device and low pit e . g . , an elevator comprising a machine room or lacking a machine room, an elevator comprising a counterweight or lacking a counterweight .

[0054] Thus , the disclosed solution can be implemented in a versatile manner in buildings with low pit .

[0055] 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 .

Claims

Claims1. A method for executing maintenance operation (18) for an elevator (1) comprising an elevator shaft (2) with a pit (11) and an apron device (Ad) mounted below an elevator car (3) for preventing falling into the elevator shaft (2) ; wherein the method comprises: executing visual inspection for the pit; and executing maintenance measures for the pit (11) in response to the detected need based on the visual inspection; char ac t e r i z e d by executing the visual inspection (22) from a lowermost landing (LI) of the elevator (1) and through a transparent protective element (Pe) of the apron device (Ad) without entering the pit (11) .

2. The method as claimed in claim 1, cha ra ct e r i z e d by moving (20) the elevator car (3) for the visual inspection (22) to a first maintenance position (Mpl) wherein a bottom (15) of the elevator car (3) is above the lowermost landing (LI) and the transparent protective element (Pe) of the apron device (Ad) protects a gap between the lowermost landing (LI) and the bottom (15) of the elevator car (3) .

3. The method as claimed in claim 2, cha ra ct e r i z e d by moving (25) the elevator car (3) after the visual inspection (22) from the first maintenance position (Mpl) in upward direction to a second maintenance position (Mp2) and thereby forming a limited open gap (16) between a lowermost end of the transparent protective element (Pe) of the apron device (Ad) and the lowermost landing (LI) ;and executing at least one maintenance task (26, 27) remotely from the lowermost landing (LI) and through the open gap (16) for the pit (11) .

4. The method as claimed in any one of the preceding claims 1 - 3, char ac t e r i z e d by executing (32) at least one maintenance task (26, 27) after the visual inspection (22) through at least one of the following openable elements of the elevator car (3) : a floor (34) , a floor hatch (35) , a wall panel (37) , a wall hatch ( 38 ) .

5. The method as claimed in any one of the preceding claims 1 - 4, char ac t e r i z e d by the maintenance measures (26, 27) after the visual inspection (22) include at least removal of foreign matter (26) remotely from the pit (11) without entering the pit (11) •6. The method as claimed in any one of the preceding claims 1 - 5, char ac t e r i z e d by providing the apron device (Ad) with a protective element (Pe) made of transparent plastic material (31) .

7. An elevator (1) comprising: an elevator shaft (2) ; an elevator car (3) supported vertically movably inside the elevator shaft (2) ; a hoisting machinery and suspension elements for moving and supporting the elevator car (3) ; several landings (L) ; a pit (11) of the elevator shaft (2) below a lowermost landing (LI) ; at least one control unit (CU) for controlling operation of the elevator (1) ;and wherein the elevator car (3) is provided with an apron device (Ad) comprising at least one vertically orientated protective element (Pe) for preventing falling into the elevator shaft (2) ; char ac t e r i z e d in that the at least one vertically orientated protective element (Pe) of the apron device (Ad) is made of transparent plastic material (31) at least partly; and the control unit (Cu) comprises a maintenance mode (19) for moving the elevator car (3) to a first maintenance position (Mpl) wherein a bottom (15) of the elevator car (3) is located above the lowermost landing (LI) and wherein visual inspection (22) of the pit (11) is executable through the transparent protective element (Pe) .

8. The elevator as claimed in claim 7, char ac t e r i z e d in that the maintenance mode (19) is configured to move (25) the elevator car (3) selectively upwards to a second maintenance position (Mp2) wherein an open gap (16) with limited height is formed between the lowermost landing (LI) and a lower end of the transparent protective element (Pe) .

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