[0001] The invention relates to an elevator car comprising a support for a payload to be
transported by the elevator car and to an elevator comprising such an elevator car.
Furthermore, the invention relates to a method for controlling such an elevator car.
[0002] A conventional traction elevator comprises a brake located in the hoisting machine
in the machine room or in the shaft top. Normally, a further safety brake or safety
gear is located on the elevator car. Such a brake and safety system is known from
EP 0 183 616 A2. Furthermore,
US 5,033,587 discloses an elevator system comprising a braking means disposed upon an elevator
car for stopping the car and an auxiliary braking device disposed upon a counterweight
for preventing inertial travel thereof. In detail, the braking means is mounted on
the bottom of the car for stopping the car at a floor upon request or in an emergency.
Furthermore, by providing an auxiliary braking device in the counterweight, overrun
of the counterweight is minimized.
[0003] However, very often after landing it is necessary to open and close the main elevator
brake in order to stop the elevator car exactly at a height level substantially identical
to the landing floor level (due to control inaccuracies or changing car payload).
Thus, it is necessary to open and close the main brake several times until the car
is in the correct level. This braking procedure is laborious and jerky.
[0004] It is an object of the invention to improve the landing operation of an elevator
car and the passengers' comfort.
[0005] According to the present invention an elevator car comprising a support for a payload
to be transported by the elevator car is characterized by a support levelling system
for levelling the support independently from the elevator car. Thus, it is not necessary
to open and close the main brake several times. In this way a substantially jerk-free
and safer levelling or re-levelling and almost perfect landing accuracy is achieved.
Especially a platform supporting the passengers can be levelled to bring this platform
within a predetermined level range.
[0006] Preferred embodiments of the elevator car according to the invention are described
in claims 2 to 15.
[0007] In one such preferred embodiment the support levelling system is equipped for moving
or levelling the support in a predetermined levelling range. Preferably, this levelling
range is about 200 mm, especially about 100 mm.
[0008] According to a preferred embodiment the support levelling system is mounted inside
a casing of the elevator car, especially in an area between the support and the casing.
However, it is also possible to mount the support levelling system in an upper area
of the casing of the elevator car, for example above a ceiling of the car or on a
frame of the car.
[0009] In another preferred embodiment the support levelling system comprises a support
drive for moving and/or levelling the support. The support drive can be electric,
hydraulic or pneumatic drive. For example, the support drive comprises at least one,
preferably four, linear motors and/or at least one piston.
[0010] In order to compensate vibrations during travelling and/or landing operation of the
elevator car a damping unit can be provided. This damping unit can be integrated into
or linked to the support drive.
[0011] In a further embodiment the support position system for determining the support position
relative to a fixed level, especially relative to a landing floor, is provided. Such
a support position system can comprise at least one sensor mounted to the car, especially
to the support. Furthermore, an accelerometer can be useful for sensing the acceleration
or speed of the movement of the support. Preferably, the support is a platform arranged
inside the elevator car.
[0012] In a further embodiment a support drive control is connected with the support drive
for controlling the support drive. Hence, the support levelling system can be operated
independently from the elevator car. Furthermore, the support position system can
be connected with the support drive control.
[0013] Furthermore, a car brake can be mounted to, on or in the car for stopping the elevator
car in normal service and/or in emergency situations, for example as a safety gear.
[0014] According to the present invention an elevator comprises an elevator car according
to one of the claims 1 to 15. Preferred embodiments of the elevator according to the
invention are described in claims 17 to 20.
[0015] In a preferred embodiment the elevator comprises an elevator car brake, wherein the
support levelling system for levelling the support is independent from the elevator
car brake. The elevator car brake can be mounted to, on or in the car for engaging
or disengaging guide rails in order to stop the elevator car in normal service and/or
in emergency situations. In other words, the elevator car brake has the two functions
to open and close as a standard brake during normal service and to close as a standard
safety gear during emergency conditions. However, no exact landing accuracy is necessary
for the elevator car brake, as this fine levelling is performed by means of the support
levelling system according to the invention.
[0016] In a further preferred embodiment a car position system comprises a car controller,
a main electric drive or frequency converter and a main elevator controller.
[0017] According to another embodiment, the elevator comprises several landing floors and
a support position system for determining the support position relative to the landing
floors, wherein the support position system comprises at least one sensor mounted
to the elevator car and several receivers each mounted to a landing floor. The sensor
can be equipped for detecting both the support position and the car position.
[0018] In a method according to the invention for controlling an elevator car having a support
for a payload to be transported by the elevator car, a support levelling system levels
the support independently from the elevator car. Preferably, the support levelling
system is driven and/or stopped independently from the elevator car. Preferred embodiments
of the method according to the invention are described in claims 22 to 30.
[0019] In a preferred embodiment of the method, the support levelling system is equipped
for moving/levelling the support in a predetermined levelling range. The support levelling
system can be moved by means of a support drive. Preferably, the support is moved
within a levelling range of about 200 mm, especially within a levelling range of about
100 mm. Furthermore, the support can be moved within an area inside a casing of the
elevator car, especially in an area between the support and the casing.
[0020] In a further preferred embodiment a damping unit compensates vibrations occurring
during travelling and/or landing of the elevator car.
[0021] In another preferred embodiment a support position system determines the support
position relative to a fixed level, especially relative to a landing floor.
[0022] Furthermore, an accelerometer can sense the acceleration or speed of the support.
[0023] According to a further embodiment a support drive control connected with the support
drive controls operation of the support drive. Furthermore, the support position system
can communicate with the support drive control. In another preferred embodiment an
elevator car brake stops the elevator car in normal service and/or in emergency situations.
[0024] In the following the invention is further described with reference to Fig. 1, which
shows an elevator 100 with an elevator car 10 movably along guide rails 104 and mounted
within a shaft 102 of a building. The building comprises several landing floors, inter
alia landing floors 70, 72. In a machine room on the top of the shaft 102 an elevator
car drive 106 having a traction pulley 107 is mounted. Furthermore, the elevator drive
system in Fig. 1 shows a guide pulley 108 and a traction belt 109.
[0025] The elevator car 10 comprises a casing 12 supported by a frame (not shown), wherein
the casing 12 includes a ceiling 15, a bottom 16, walls 17 and a car door 18. Furthermore,
the car 10 has a support 20 in the form of a platform for the payload to be transported
by the elevator car 10. This platform divides the space enclosed by the casing 12
into an upper area 13 and a lower area 14.
[0026] Furthermore, a support levelling system 30 is provided in order to level or move
the support 20 in a specific levelling range R. Thus, the support 20 can be levelled
independently from the elevator car 10. To raise and lower the platform the support
levelling system 30 comprises a support drive 40, for example a telescopic piston
42.
[0027] Furthermore, the elevator car 10 comprises a support drive control 50 and a support
position system 60. The support position system 60 comprises a sensor 62 integrated
in the support platform and a receiver 64 mounted on each landing floor 70, 72. Sensor
62 and receiver 64 communicate with each other and with the support drive control
50 in order to determine the position of the support 20 relative to the landing floor
level 70.
[0028] In case that the difference between the height of the surface of the support 20 and
the height of the surface of the landing floor 70 is not within the predetermined
levelling range R, for example +/- 50 mm far from the receiver's height, the support
drive control 50 initiates a signal to the support drive 40 in order to move the platform
20 in a direction to bring the surface of the support 20 within the levelling range,
especially to the exact landing height of the landing floor 70.
[0029] In order to determine the position and/or height of the elevator car 10 within the
shaft 102, the elevator system of Fig. 1 further comprises a car position system 110
having a sensor 112 mounted to the casing 12 of the car 10 and receivers 114 mounted
along the shaft 102, for example at the landing floors 70, 72. As indicated in Fig.
1, it is possible to combine the functions of sensors 62 and 112 and/or of receivers
64 and 114 or to mount both to the landing floors 70, 72.
[0030] Furthermore, the car position system 110 comprises a car control unit 120, a main
electric drive and/or frequency converter 130 and a main elevator controller 140.
Based on this car position system 110, the "raw" car position can be derived from
the main motor relative distance. The raw car positioning algorithm is distributed
and achieved by a "triangulation" between car control unit 120, main electric drive
or frequency converter 130 and main elevator controller 140. In other words, the car
position system 110 serves as a "raw" levelling system, whereas the system 30 serves
as a "fine" levelling system.
[0031] In order to stop the elevator car 10, a car brake 90 is mounted to the bottom 16
of the casing 12. The car brake 90 engages or disengages the guide rails 104. The
car brake 90 opens and closes as the standard brake during normal service and also
closes as a standard safety gear during emergency situations.
[0032] To coordinate the travelling and landing operation the support position system 60
is connected with the car position system 110 and/or car control unit 120, and/or
main electric drive / frequency converter 130 and/or main elevator controller 140.
[0033] In order to compensate vibrations during travelling and/or landing process, for example,
if linear motors are used for the support drive 40, a damping unit (not shown) can
be integrated into the support levelling system 30. Furthermore, an accelerometer
(not shown) can be incorporated to or linked to the support drive control 50.
[0034] The elevator system described above allows using lighter, more elastic traction belts
109 also for higher travelling heights. Furthermore, as the car brake 90 serves as
main brake and as a safety gear system, further material and cost reduction is possible.
Furthermore, the levelling and relevelling of the support 20 is jerk-free and safer.
The landing accuracy increases. In detail, it is not necessary to reopen and close
the brake for levelling the support.
1. Elevator car (10) comprising a support (20) for a payload to be transported by the
elevator car (10), characterised by a support levelling system (30) for levelling the support (20) independently from
the elevator car (10).
2. Elevator car (10) according to claim 1, characterised in that the support levelling system (30) is equipped for moving the support (20) in a predetermined
levelling range (R).
3. Elevator car (10) according to claim 2, characterised in that the levelling range (R) is about 200 mm, preferably about 100 mm.
4. Elevator car (10) according to one of the claims 1 to 3, characterised in that the support levelling system (30) is mounted inside a casing (12) of the elevator
car (10), especially in an area (14) between the support (20) and the casing (12).
5. Elevator car (10) according to one of the claims 1 to 4, characterised in that the support levelling system (30) comprises a support drive (40) for moving the support
(20).
6. Elevator car (10) according to claim 5, characterised in that the support drive (40) is a hydraulic or pneumatic drive.
7. Elevator car (10) according to one of the claims 5 or 6, characterised in that the support drive (40) comprises at least one, preferably four, linear motors and/or
at least one piston (42).
8. Elevator car (10) according to one of the claims 1 to 7, characterised by a damping unit for compensating vibrations during travelling and/or landing of the
elevator car (10).
9. Elevator car (10) according to claim 8, characterised in that the damping unit is integrated into or linked to the support drive (40).
10. Elevator car (10) according to one of the claims 1 to 9, characterised by a support position system (60) for determining the support position relative to a
fixed level, especially relative to a landing floor (70, 72).
11. Elevator car (10) according to claim 10, characterised in that the support position system (60) comprises at least one sensor (62) mounted to the
elevator car (10), especially to the support (20).
12. Elevator car (10) according to one of the claims 1 to 11, characterised by an accelerometer for sensing the acceleration or speed of the movement of the support
(20).
13. Elevator car (10) according to one of the claims 1 to 12, characterised by a support drive control (50) connected with the support drive (40) for controlling
the support drive (40).
14. Elevator car (10) according to one of the claims 1 to 13, characterised in that the support (20) is a platform arranged inside the elevator car (10).
15. Elevator car (10) according to one of the claims 1 to 14, characterised by a car brake (90) mounted to, on or in the car (10) for stopping the elevator car
(10) in normal service and/or in emergency situations.
16. Elevator (100) characterised by an elevator car (10) according to one of the claims 1 to 15.
17. Elevator (100) according to claim 16, characterised by an elevator car brake (90), wherein the support levelling system (30) for levelling
the support (20) is independent from the elevator car brake (90).
18. Elevator (100) according to claim 16 or 17, characterised in that the elevator car brake (90) is mounted to, on or in the elevator car (10) for engaging
or disengaging guide rails (104) in order to stop the elevator car (10) in normal
service and/or in emergency situations.
19. Elevator (100) according to one of the claims 16 to 18, characterised by a car position system (110) comprising a car controller (120), a main electric drive
or frequency converter (130) and a main elevator controller (140).
20. Elevator (100) according to one of the claims 16 to 19, characterised by landing floors (70, 72) and a support position system (60) for determining the support
position relative to the landing floors (70, 72), wherein the support position system
(60) comprises at least one sensor (62) mounted to the elevator car (10) and several
receivers (64) each mounted to a landing floor (70, 72).
21. Method for controlling an elevator car (10) comprising a support (20) for a payload
to be transported by the elevator car (10), characterised in that a support levelling system (30) levels the support (20) independently from the elevator
car (10).
22. Method according to claim 21, characterised in that the support levelling system (30) is equipped for moving the support (20) in a predetermined
levelling range (R).
23. Method according to one of the claims 21 or 22, characterised in that the support levelling system (30) is moved by means of a support drive (40).
24. Method according to one of the claims 21 to 23, characterised in that the support (20) is moved within a levelling range (R) of about 200 mm, preferably
of about 100 mm.
25. Method according to one of the claims 21 to 24, characterised in that the support (20) is moved within an area inside a casing of the elevator car (10),
especially in an area (14) between the support (20) and the casing (12).
26. Method according to one of the claims 21 to 25, characterised in that a damping unit compensates vibrations occurring during travelling and/or landing
of the elevator car (10).
27. Method according to one of the claims 21 to 26, characterised in that a support position system (60) determines the support position relative to a fixed
level, especially relative to a landing floor (70, 72).
28. Method according to one of the claims 21 to 27, characterised in that a accelerometer senses the acceleration or speed of the support (20).
29. Method according to one of the claims 21 to 28, characterised in that a support drive control (50) connected with the support drive (40) controls operation
of the support drive (40).
30. Method according to one of the claims 21 to 29, characterised in that a car brake (90) stops the elevator car (10) in normal service and/or in emergency
situations.