Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
ELEVATOR WITH AN ELEVATOR CAR SAFETY DEVICE ACTING ON THE STATOR BEAM
Document Type and Number:
WIPO Patent Application WO/2021/008701
Kind Code:
A1
Abstract:
The invention relates to an elevator (10) comprising at least one stator beam (18) having a least one stator rail (50) with stator teeth, which stator beam (18) is located vertically in an elevator shaft (12) The elevator further comprises at least one elevator car (16) with at least one mover (24, 26) configured to move along the stator beam (18) and co-act with the poles or teeth of the stator rail (50) as to drive the elevator car (16) in the elevator shaft (12), which stator beam (18) has at least two vertical sides (80) facing in different directions, the mover co-acting with the stator rail forming a linear motor, which is driven by a motor drive connected with an elevator control. According to the invention the elevator has an emergency stop arrangement comprising an emergency stop control (72) and a safety device (70) for the mover (24, 26), the safety device (70) comprising a support collar (76) embracing at least two opposing vertical sides (80) of the stator beam (18), which vertical sides (80) act as slide surfaces. The collar (76) carries at least two sliders (90) facing said slide surfaces (80) of the stator beam (18), each slider (90) comprising a cylinder (92) fixed to the collar (76) and a piston (94) being movable in said cylinder (92) and connected with the sliding shoe (96), which sliding shoe (96) carries at least one sliding pad (98) facing at least one of said slide surfaces (80) of the stator beam (18), the sliding shoe (96) is movable via the piston (94) with a component perpendicular to a plane of the adjacent slide surface (80) of the stator beam (18), which piston (94) is movable via an actuating mechanism (82), configured to be triggered at least via the emergency stop control in case of power-off of the linear motor. Via this arrangement the air gap between mover and stator rail is maintain in case of power-off and excessive deceleration of the elevator car is avoided.

Inventors:
KORHONEN TUUKKA (FI)
PUROSTO TERO (FI)
RATIA JOUNI (FI)
HAKALA TERO (FI)
SUUR-ASKOLA SEPPO (FI)
Application Number:
PCT/EP2019/069222
Publication Date:
January 21, 2021
Filing Date:
July 17, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KONE CORP (FI)
International Classes:
B66B5/16; B66B11/04
Domestic Patent References:
WO2016207136A12016-12-29
Foreign References:
CN106892321A2017-06-27
CN104876099A2015-09-02
CN102040139A2011-05-04
KR20190049412A2019-05-09
Attorney, Agent or Firm:
GLÜCK KRITZENBERGER PATENTANWÄLTE PARTGMBB (DE)
Download PDF:
Claims:
Patent claims:

1. Elevator (10) comprising at least one stator beam (18) having a least one stator rail (50) with stator teeth, which stator beam (18) is located vertically in an elevator shaft (12), the elevator further comprising at least one elevator car (16) with at least one mover (24, 26) configured to move along the stator beam (18) and co-act with the poles or teeth of the stator rail (50) as to drive the elevator car (16) in the elevator shaft (12), which stator beam (18) has at least two vertical sides (80) facing in different directions, the mover co-acting with the stator rail forming a linear motor, which is driven by a motor drive connected with an elevator control,

characterized in that the elevator has an emergency stop arrangement comprising an emergency stop control (72) and a safety device (70) for the mover (24, 26), the safety device (70) comprising a support collar (76) embracing at least two opposing vertical sides (80) of the stator beam (18), which vertical sides (80) act as slide surfaces, the collar (76) carrying at least two sliders (90) facing said slide surfaces (80) of the stator beam (18), each slider (90) comprising a cylinder (92) fixed to the collar (76) and a piston (94) being movable in said cylinder (92) and connected with the sliding shoe (96), which sliding shoe (96) carries at least one sliding pad (98) facing at least one of said slide surfaces (80) of the stator beam (18), the sliding shoe (96) is movable via the piston (94) with a component perpendicular to a plane of the adjacent slide surface (80) of the stator beam (18), which piston (94) is movable via an actuating mechanism (82), configured to be triggered at least via the emergency stop control in case of power-off of the linear motor.

2. Elevator (10) according to claim 1, characterized in that the emergency stop control (72) is connected with the motor drive of the linear motor and is configured to perform the triggering of the actuating mechanism (82) in response to a power output signal of the motor drive.

3. Elevator (10) according to one of the preceding claims, characterized in that the support collar (76) is mounted at or integrated in a mover housing of the mover.

4. Elevator (10) according to one of the preceding claims, characterized in that the emergency stop control (72) is connected with the output of an acceleration sensor located in connection with the elevator car, and is configured to trigger and/or to adjust the actuating force of the actuating mechanism (82) dependent on the sensor signals.

5. Elevator (10) according to one of the preceding claims, characterized in that the emergency stop control (72) is connected with the output of floor- or door zone sensor and is configured to release and/or to adjust the actuating force of the actuating mechanism (82) dependent on the sensor signals.

6. Elevator (10) according to one of the preceding claims, characterized in that the actuating mechanism (82) comprising at least one cartridge (114) with a compressed gas and/or explosive as well as at least one gas lead (113, 111, 104) connecting the cartridge (114) and the cylinder (92) as well as a trigger device (112) for the actuating mechanism (82).

7. Elevator (10) according to claim 6, characterized in that the trigger device (112) comprises a shut-off valve in the gas lead (113, 111, 104).

8. Elevator (10) according to claim 7, characterized in that the shut-off valve is biased in open direction and is kept by an emergency stop control (72) in its closed position.

9. Elevator (10) according to one of claims 6 to 8, characterized in that the trigger device (112) comprises a detonator for the explosive in the cartridge (114).

10. Elevator (10) according to one of claims 6 to 9, characterized in that at least one distribution chamber (110) is located in the gas lead (113, 111, 104) between the cartridge (114) and the sliders (90).

11. Elevator (10) according to claim 10, characterized in that at least one shut-off valve is located in the gas lead (113, 111, 104) between the cartridge (114) and the distribution chamber (110).

12. Elevator (10) according to one of the preceding claims, characterized in that the stator beam (18) has a rectangular, particularly square base profile with four stator rails (50) and that the slide surfaces (80) are located on connecting surfaces located between the stator rails (50).

13. Elevator (10) according to claim 12 , characterized in that the support collar (76) is u or c- shaped having four inner faces facing the four stator rails (50) of a square profile stator beam (18) whereby the collar (76) supports four sliders (90) which are located in the corner areas between said faces.

14. Elevator (10) according to one of the preceding claims, characterized in that the emergency stop arrangement comprises its own backup energy supply (74).

15. Method to operate an elevator according to one of the preceding claims during an emergency stop, characterized in that the magnetizing current id is kept constant during emergency braking.

Description:
ELEVATOR WITH AN ELEVATOR CAR SAFETY DEVICE ACTING ON THE

STATOR BEAM

The present invention relates to an elevator with a linear motor comprising at least one stator beam having a least one stator rail with stator teeth, which stator beam is located vertically in an elevator shaft. The inventive elevator further comprises at least one elevator car with at least one mover configured to move along the stator beam and co-act with the teeth of the stator rail as to drive the elevator in the elevator shaft. The stator beam has at least two vertical sides facing in different directions. Such an elevator according to the pre-amble of claim 1 is e.g. known from WO 2016/207136 Al. As such an elevator construction doesn't have a counterweight, it is much more sensible against any disturbance in the operation than common traction sheave elevators have a car and counterweight. In common counterweight elevators the driving force for the movement of the elevator car is only the difference between the car weight inclusive its load and the

counterweight whereby also the mechanic friction of all systems has a limiting effect on the movement. But in the above-mentioned kind of inventive linear motor concept, the elevator car would after e.g. a loss of the motor force immediately fall downwards subjected the earth gravity acceleration. Additionally in case of power-off, the air gap between stator rail and mover collapses which adds to the deceleration. Particular relevance has this phenomenon with upwards travel. The deceleration caused by gravity adds in this case up to the deceleration caused by the collapse of the air gap, leading to the stator rail and mover clutching together.

It is object of the present invention to improve the safety of an elevator having a linear motor concept with leads to a smoother deceleration in case of mains power-off.

The above-mentioned object is solved with an elevator according to claim 1. Preferred

embodiments of the invention are subject-matter of the dependent claims.

The inventive elevator comprises at least one stator beam having a least one stator rail with stator teeth, which stator beam is located vertically in an elevator shaft. The elevator further comprises at least one elevator car with at least one mover configured to move along the stator beam and co acting with the poles or teeth of the stator rail as to drive the elevator car in the elevator shaft.

The stator beam has at least two vertical sides facing in different directions, and the mover co-acts with the stator rail forming a linear motor, which is driven by a motor drive connected with an elevator control.

According to the invention the elevator has an emergency stop arrangement comprising an emergency stop control and a safety device for the mover. The safety device comprises a support collar embracing at least two opposing vertical sides of the stator beam, which vertical sides act as slide surfaces. The collar carries at least two sliders facing said slide surfaces of the stator beam, each slider comprising a cylinder fixed to the collar and a piston being movable in said cylinder and connected with the sliding shoe. The sliding shoe carries at least one sliding pad facing at least one of said slide surfaces of the stator beam. The sliding shoe is movable, via the piston with a component perpendicular to a plane of the adjacent slide surface of the stator beam. Thus the slide shoe is pressed via the piston against the slide surface. The piston is movable via an actuating mechanism, configured to be triggered at least via the emergency stop control in case of power-off of the linear motor. The piston is further optionally configured to be triggered via additional signals, e.g. the signal of a safety chain of the elevator monitoring the function of the elevator components and/or an over speed-governor. Of course the triggering of the piston to activate the slide mechanism can also happen in other per se known safety relevant cases as door open,

mismatching sensor signals, power off, mismatching control signals, shaft entry etc. Via activation of the slide mechanism the deceleration of the car in case of power of is reduced compared to a situation where the mover clutches on the stator rail in case the air gap between stator rail and mover collapses.

Preferably, the emergency stop control is connected with the motor drive of the linear motor and is configured to perform the triggering of the actuating mechanism in response to a power output signal of the motor drive. The emergency stop then gets timely information about the expected collapse of the air gap and is able to trigger the piston timely before the mover starts to clutch on the stator rail.

In a preferred embodiment of the invention the support collar is mounted at or integrated in a mover housing of the mover. This arrangement is space saving and combines the points of force interaction of the car (acceleration as well as deceleration) with the stator beam. The structural reinforcement of the elevator car can then be focussed on the mover mountings.

Preferably, the emergency stop control is connected with the output of an acceleration sensor located in connection with the elevator car, and is configured to trigger and/or to adjust the actuating force of the actuating mechanism dependent on the sensor signals. Thus the emergency stop control is also able to trigger the piston(s) in case of over speed.

In a preferred embodiment of the invention the emergency stop control is connected with the output of floor- or door zone sensor and is configured to release and/or to adjust the actuating force of the actuating mechanism dependent on the sensor signals. Thus, the emergency stop control is able to bring the elevator car to a halt in the vicinity or at a door zone as to enable the release of passenger without any trap situation.

The actuating mechanism comprises at least one cartridge with a compressed gas and/or explosive material as well as at least one gas lead connecting the cartridge and the cylinder as well as a trigger device for the actuating mechanism. The cartridge comprising compressed gas and/or explosives is able to provide a sufficient over-pressure in the gas leads to immediately actuate the pistons as to activate the sliders, which is particularly relevant for linear elevator concepts as no counterweight is present which could hamper the movement of the elevator car downwards.

Therefore, in case of a possible drop of the elevator car, an immediate activation of the sliders is advantageous, which is realised with the over-pressure arrangement between cartridge and the cylinder arrangement of the slider, comprising the cylinder and the piston moving in it. Preferably, the trigger device comprises a shut-off valve in the gas lead, which allows a fast and easy triggering of the pistons.

Preferably, the shut-off valve is biased in open direction and is kept by an emergency stop control or elevator control in its closed position. In any case of general power-off the closing force of the emergency stop control or elevator control drops and the shut-off valve opens as to actuate the pistons. This arrangement is very reliable and safe, as electrical power-offs immediately lead to a triggering.

Preferably the base surface of the piston in the cylinder is at least 10 cm 2 , preferably at least 20 cm 2 , possibly up to 100 cm 2 . If the over-pressure is 50 bar or in case of an explosive much higher, this would correspond to braking force of 500 kg, 1000 kg or 5000 kg per slider and would thus be sufficient to induce an immediate emergency stop.

A further advantage of the invention is that the stator beam/mover-arrangement could also be used instead of a guide rail and via the inventive safety device the emergency gripping action which was till now realized by gripping devices wedging the guide rails could be transferred to the stator beam/mover arrangement.

According to the invention, the safety device acts directly on the stator beam and not on separate guide rails as known in the art. The actuating mechanism comprises for each slider a cylinder fixed to the collar and a piston connected to the sliding shoe and movable in said cylinder. Generally, the piston could be connected with the sliding shoe via a lever mechanism or a scissor mechanism but preferably, the sliding shoe is directly formed or carried by the piston itself so that the sliding pad is arranged on the front side of the piston facing the vertical side of the stator beam which acts as a slide surface.

In the above mentioned safety relevant cases the actuating mechanism is then triggered by a trigger device which cares for the pressure appliance from the cartridge to the cylinder. In case of a compressed gas cartridge this could be a shut-off valve arranged in the gas lead which in a safety relevant operating condition of the elevator opens and thus lets the over-pressure get from the cartridge(s) to the cylinders of the sliders. In case of a cartridge containing at least one explosive the triggering device is advantageously a detonator letting the explosive explode so that the pressure wave from the explosive immediately progressed to the cylinders and move the sliding shoes with high force against the slide surfaces of the stator beam. The reaction time is in the area of a few milliseconds and leads to a soft guiding of the car along the guide rails in case of a sudden loss of power and imbalance of the magnetic forces which would otherwise lead to a hard grip of the mover on the stator beam. Accordingly, the gripping action of this safety device is very fast and guides the elevator car along the stator beams in only a few milliseconds softly, thereby avoiding excessive deceleration. Accordingly, the safety level of such a safety device is increased essentially. Furthermore, via the overpressure in the cartridge or via the selection of the explosive material in the cartridge it is possible to adjust the braking force of the sliding pad against the vertical sides of the stator beam as to provide an immediate and sufficient force to keep the elevator fixed to the stator beam and on the other hand low enough as to prevent damage or injuries by the sudden stopping movement of the elevator car upon triggering of the actuating mechanism, i.e. operating the trigger device.

Preferably, there are at least two vertical stator beams located parallel in the elevator shaft and the elevator car has two, preferably four movers whereby at least one, preferably two movers are in counteraction with one stator beam, respectively. The provision of two or more stator beams has a positive effect on the guiding function of the stator beam/mover arrangement. In case of two (ore even more) parallel stator beams the guiding function is distributed analogue to the provision of two guide rails as known in the art. Thus, the stator beam/mover arrangement is adapted to provide the guide function for the elevator car instead of using guide rails. Thus preferably, the stator beam/mover arrangement replaces the guide rails. Of course this requires that the linear motors formed by the stator beam/mover arrangements are configured to comprise an air gap control, so that the width of the air gaps between each stator rail and the corresponding active parts of the mover can be controlled to be adjusted to a desired width.

Preferably, the elevator car has at least one safety device per stator beam, preferably two safety devices, whereby one safety device is preferably located in the vicinity of a corresponding mover, preferably in the upper part of the elevator car. Via multiple safety devices, the braking force is doubled or quadrupled, if preferably two stator beams and two movers per stator beam are used.

Preferably, the actuating mechanism comprises a (solenoid) shut-off valve in the gas lead. In this case, the triggering of the actuating device is realized by operating said shut-off valve which is preferably a solenoid valve. Preferably, in this case the shut-off valve is biased in open direction by a mechanical spring device and is kept by a controller, e.g. an emergency stop control in its closed position. This arrangement has the advantage that in any case of power off, the shut-off valve is immediately opened and the sliding pads are pressed by the overpressure in the cartridge against the slide surfaces formed by the vertical sides of the stator beam. This arrangement again increases the safety of the elevator concept. Of course, the shut-off valve is preferably reasonable in case a cartridge with overpressure is used.

In an embodiment, where the cartridge comprises an explosive material, the trigger device comprises a detonator for the explosive, for example an electric detonator or ignitor. This allows very fast actuation of the safety device to stop the elevator car before any harmful situation might occur.

Preferably, a backup energy supply is provided for the safety device so that any emergency stop action which necessitates electric energy can be kept up in any case of power off. This essentially increases the safety of the elevator. In a preferred embodiment of the invention, at least one distribution chamber is located in the gas lead between the cartridge and the sliders. Via this arrangement it is possible to use one cartridge for several sliders so that it is not necessary to provide several cartridges, e.g. one cartridge for each of the sliders. Preferably, in this case, the shut-off valve is located in the gas lead between the cartridge and the distribution chamber. This has the advantage that only one shut-off valve, e.g. a solenoid valve, is necessary to connect or disconnect the cylinders of each slider with the cartridge. Thus, an emergency braking can be realized by opening this one shut-off valve which is preferably biased in its open position by a mechanical spring arrangement and all sliders are activated simultaneously.

In this case advantageously the at least one shut-off valve is located in the gas lead between the cartridge and the distribution chamber, allowing one shut-off valve for all pistons of the emergency stop device.

Preferably, the length of the gas leads to each slider can be made identical so that the delay from opening the shut-off valve and slider actuation is the same for each slider. This ensures the simultaneous activation of all sliders.

According to a preferred embodiment of the invention, the stator beam has a rectangular, particularly square base profile with four stator rails. Via this arrangement, a very rigid stator beam is provided which is able to take up the considerable forces which come up in case of an emergency stop by activating the safety device. Preferably, in this case, the vertical sides forming the slide surfaces are located on connecting faces located between the stator rails. This has the advantage that the sliding pads do not act on the stator rails themselves. Accordingly, the stator rails are not going to be affected in case of an emergency braking. This solution advantageously provides a clear separation between the stator rails of the stator beam which drive the elevator car and the connecting faces between said stator rails which only act as slide surface and do not interfere with the stator rails.

Preferably, the vertical sides are located with respect to the adjacent stator rails in an angle of 30 to 60 degrees, preferably 45 degrees. Via this arrangement, it is ensured that an action of the sliding shoes on the vertical sides of the stator beam does not affect the stator rails.

In a preferred embodiment of the invention, the support collar has a massive u- or c-shaped support collar body having four inner faces facing the four stator rails of a square profile stator beam whereby the collar supports four sliders located in the corner areas between said inner faces. Again, in this embodiment, the function of braking and the driving is clearly separated so that both do not interact with each other. Further , the massive collar body is configured to take up the considerable guiding forces of the sliders which avoids a spreading the members of the profile body. A massive support collar body has the advantage that it on one hand takes up the large forces in case of an emergency stop. On the other hand the massive construction is insensible against mechanical impacts and dirt. In this connection , the gas leads, cartridges and cylinders of the sliders are formed or integrated as replaceable parts within the massive body so that the gas leads and cartridges are configured to handle very high pressure, particularly in case explosives are used in the cartridges. The pressure may go up to several hundreds of bars which is taken up within the massive, preferably one-piece or two-piece body. A two-piece body with two almost identical mirrored parts can preferably be opened in the collar plane as this allows access to all gas leads and cartridges and is on the other side very rigid after mounting the two parts together.

The collar may be closed or have a slit which enables moving parts out from opening surrounded by the inner faces of the collar.

In an alternative embodiment, the vertical sides are formed by the stator rails with the stator teeth. In this case, the stator rails themselves form the slide surface. Although this embodiment is not preferred as their braking might affect the function of the stator rails, this embodiment might be chosen if the circumstances do not allow a separate arrangement of stator rails and vertical sides (slide surfaces).

In a preferred embodiment of the invention, a ratchet mechanism is arranged between the sliding shoe/piston and the slider body/cylinder, which prevents withdrawal of the sliding shoe after triggering of the actuation mechanism. Via this ratchet mechanism, it is ensured that the sliding pad keeps in braking contact with the slide surface. Generally, the force maintaining the sliding pads in contact with the slide surface is the overpressure in the gas lead after triggering the actuating mechanism. However, there is the possibility that the whole arrangement of cartridge gas lead and cylinder piston arrangement of each slider is not absolutely gas tight so that there might be a loss of pressure over the time. Furthermore, it might be preferable to release the

overpressure in the gas lead as to be able to move the elevator car after triggering of the actuating mechanism. Therefore, a mechanical ratchet mechanism which keeps the sliding shoe pressed against the slide surface even in case the over-pressure vanishes from the gas lead might be advantageous.

In a preferred embodiment of the invention, the ratchet mechanism is coupled to a release mechanism which can be actuated via a control panel or a release lever. In this case, the fixing of the elevator car to the stator beam can be automatically or manually released for releasing trapped passengers in an emergency ride.

In a preferred embodiment of the invention, the elevator comprises an emergency release mechanism which is able to apply during an emergency ride a reduced gas pressure in the gas lead to allow the adjustment of the slider force and thus a restricted movement of the elevator car along the stator beam. With this embodiment, the pressure in the gas lead is adjustable as to allow the release of trapped passengers so that the elevator car can drive safely with a reduced speed to the next exit. In this case, the safety device is preferably configured to still being able to trigger the actuating mechanism in case of over-speed. Via this arrangement it is ensured that an over-speed situation might not evolve during an emergency ride situation. Thus, also during emergency ride, the function of the safety device still remains intact and the emergency ride is safe.

In a preferred embodiment of the invention, the trigger device is connected to an emergency stop control or controller which receives data at least from an over-speed governor of the elevator and which is configured to operate the trigger device. Via this arrangement, the elevator is effectively ensured against each kind of unsafe operating situations.

In this case, preferably, the emergency stop control is connected to a speed sensor connected to the elevator car, and the emergency stop control is configured to operate the trigger device if either the over-speed governor or the speed sensor indicates over-speed. This arrangement still increases the safety level as aside the over-speed governor an internal speed sensor of the elevator car is used to monitor the elevator car speed. If already one of these signals exceeds a certain threshold indicating an over-speed, the trigger device is operated, i.e. the actuating mechanism is triggered.

In a still improved arrangement, the emergency stop control is configured to compare data from at least two movement detecting devices and to trigger the actuating mechanism if either there is a mismatch in the speed detected or calculated from the two movement detecting devices. Via this measure, a redundancy check on the car speed is provided whereby the actuating mechanism is not triggered only in case of over-speed but also in case that two movement detecting devices lead to different car speeds of the elevator car. With the term "movement detecting devices" each device is meant which is able to derive a speed signal from whatever position signal as speed sensor, accelerometer or magnetometer as well as position sensor.

It is clear for the skilled person that the components of the invention may be provided single or multiple. This regards particularly to the cartridges , the gas leads and the sliders. Each slider may have a multiple cylinder arrangement.

The linear motor is preferably a FSPM linear motor allowing easy control, also of the air gaps, so that the linear motors (stator beam/mover arrangements) can easily act as guides for the elevator car along the elevator shaft. Of course, the inventive concept is provided for the use of multiple elevator cars in one elevator shaft.

The emergency stop control or controller operating the trigger device could be integrated in the elevator control. Anyway, it can be advantageous that the emergency stop control is located as a separate unit to the elevator car, preferably comprising its own backup energy supply and being connected with the elevator control and/or at least one safety device of the elevator control. In summary the slider comprises a cylinder supported in the collar and a piston for moving the sliding pad. The actuating mechanism comprises the at least one cartridge, the at least on gas lead for connecting the cartridge with the cylinder and a shut-off valve and/or detonator as trigger device. The trigger device is operated by the emergency stop control and preferably has its own backup energy supply.

In a preferred embodiment of the invention the slide surfaces may also be formed by the stator rails, particularly if the gaps between the stator teeth are filled with a polymer-containing filler material so that the stator rail obtains a smooth surface, which is adapted to work as slide surface.

In an inventive method to operate an elevator of the above mentioned kind during an emergency stop, a vector control is used and the magnetizing current i d is kept constant during emergency braking, whereas the propulsion current portion i q is reduced, preferably to zero. This keeps the air gaps constant in emergency case and the deceleration is then solely dependent on the action of the sliders which can be easily defined according to the slider design and the piston force.

Preferably, the kinetic/sliding friction coefficients of the sliding pads and slide surfaces are substantially low compared to conventional brake pads and brake surfaces, e.g. below 0,5.

Following terms are used as synonyms: stator beam/mover arrangement - linear motor; vertical sides - slide surfaces - connecting faces; shut-off valve - solenoid valve; emergency stop control - controller; stator - stator rail; collar - support collar;

It is clear for the skilled person that the above-mentioned embodiments can be combined arbitrarily.

Brief description of the drawings

The invention is now described hereinafter with respect to the enclosed drawing. In this drawing

Fig. 1 shows a side view of an elevator shaft with a linear elevator motor according to the invention comprising two parallel stator beams,

Fig. 2 shows a horizontal cross-section of the parts of the elevator motor and the guide rails in the area between the elevator car and the shaft wall of Fig. 1,

Fig. 3 shows a cross-section through a stator beam and a mover of Figs. 1 and 2,

Fig. 4 shows a perspective of the inventive safety device of the elevator, and

Fig. 5 a cross section through the inventive slider. Detailed description of the drawings

Fig. 1 shows an elevator 10 comprising an elevator shaft 12 wherein an elevator car 16 moves up and down. The elevator 10 has a linear elevator motor 14. The linear elevator motor 14 comprises stator rails 50 (see Figs. 2 and 3) located in vertical side faces of a stator beam 18 which is mounted with fastening elements 20 to a shaft wall 22 of the elevator shaft 12. In this example the elevator 10 has two parallel stator beams 18, which can be seen in Fig . 2.

The elevator car 16 comprises for each stator beam two movers 24, 26 located one above the other. The lower mover 24 is located in the lower half of the elevator car whereas the upper mover 26 is located in the upper half of the elevator car. These two movers 24, 26 comprise electro magnetic components as e.g. irons, windings and permanent magnets which co-act with stator teeth located in the side faces of the stator beam 18. Accordingly, the elevator car travels upwards and downwards via corresponding control of both movers 24, 26 co-acting with both stator beams 18.

The elevator car 16 has a corresponding set of two movers 24, 26 for each vertical stator beam 18 so that the elevator car 16 has in total four movers, two lower movers 24 and two upper movers 26 to co-act with two stator beams 18.

Each stator beam 18 preferably has a square profile with four stator rails 50 along its side faces as it is shown in Figs. 2 and 3. The stator beam further has vertical sides 80 connecting the stator rails 50, which vertical sides 80 form the slide surface for sliders 90 (Fig . 4) mounted in a safety device 70 arranged in the vicinity of each mover 24, 26. The safety device 70 will be explained in greater detail in connection with Figs. 4 and 5.

Although it is preferred that the stator beams 18 and movers 24, 26 of the elevator 10 of Fig . 1 also form an electro-magnetic guide for the elevator car 16 so that any guide rollers and guide rails can be omitted, Fig. 2 shows in an embodiment optional car guides 32, 34 of the elevator car 16 co-acting with optional guide rails 28 running vertically along the shaft wall 22 of Fig . 1. In this optional arrangement the shaft wall 22 comprises two parallel guide rails 28, 30 co-acting with corresponding car guides 32, 34. In this case each car guide 32, 34 has a set of guide rollers co acting with the car guide rails 28, 30. As these car guides 32, 34 in connection with the car guide rails 28, 30 are configured for a rucksack type suspension, the corresponding guide system 28, 30, 32, 34 is configured to keep the car 16 horizontally in connection with the shaft wall 22 as these both car guide rails 28, 30 are the only guide rails of the elevator car 16 in the shaft 12. Of course the car guide is preferably and simply realized alone with the stator beams 18 in co-action with the movers 24, 26, in which case the linear motors are configured to control the air gaps between each stator rail and the corresponding counter-face 54 of the movers 24, 26. The vertical stator beams 18 as well as the movers 24, 26 of the elevator car 16 are shown in more detail in Fig. 3. According to Fig . 3 the vertical stator beam 18 comprises a rigid support structure 40 with a square cross-section. The rigid support structure 40 is made of a non-magnetic material, preferably aluminum, carbon fiber or class fiber or composites thereof. On each of the four larger vertical faces the support structure 40 of the stator beam 18 carries a metal stator rail 50 comprising stator teeth, which form four side faces 42, 44, 46, 48 of the stator beam 18. Each of these stator rails (or bars) 50 forms a stator of the linear motor 14 so that the stator beam 18 shown in Fig. 3 comprises four stators which on connection with separately driven active parts of the mover form four independent linear motors which are able to perform a control and adjustment of the air gap width so that the linear motors can perform guiding function for the elevator car, obviating the need for car guide rails and car guides. The stator teeth co-act with active parts of the mover as windings, irons and permanent magnets located along counter-faces 54 in the four arms 56, 58,

60, 62 of a C-type profile of the mover 24, 26 embracing the four larger side faces 42, 44, 46, 48 of the stator beam 18 . This C-type profile of the mover surrounds the stator beam 18 but leaves an opening 64 for the adaption of the fastening elements 20 of the stator beam l8 , as the mover 24, 26 travels along the shaft 12. Vertical sides or connecting faces 80 are located between the four side faces 42, 44, 48, 48 of the stator beam 18 which connecting faces 80 act as slide surface for the sliders 90 of the safety device 70 which is explained in more detail in Fig . 4.

The stator rails 50 on all four side faces 42, 44, 46, 48 have the same pitch d. Anyway, the first and third side face 42, 46 of the stator beam may also have an identical teeth position in vertical direction whereas the second and fourth side face 44, 48 may have the same pitch but the teeth position is preferably vertically offset with respect to the stator teeth on the first and third side face 42, 46 by a ¼ pitch.

Via this arrangement, it is ensured that on one hand, the horizontal forces between the stators 50 on opposite sides eliminate each other whereas the vertical offset of the pitches of the side faces oriented rectangular leads to a better efficiency and a smoother run of the elevator motor, as a moving step of such a motor 14 is a half pitch. By the fact that four stators 50 are located within the stator beam 18 the force generated between the movers 24, 26 and the stator beam 18 is multiplied by four, thereby achieving less horizontal ripples and a smoother movement of the movers 24, 26 with respect to the vertical stator beam 18.

Fig. 4 shows a perspective view of a safety device 70 from Fig . 1. The safety device is connected to an emergency stop control 72 as shown in Fig . 1. The safety device 70 comprises a massive support collar 76 which is located preferably on top and/or bottom of the elevator car 16 so that it surrounds with an inner opening 84 the stator beam 18. The opening 84 is essentially square whereby the four long sides 86 are facing the stator rails 50 on the square stator beam 18 as e.g . shown in Figs. 2 and 3. In the corner areas of the inner opening between the four inner sides 86, at least one elevator slider 90 is provided which is explained in more detail in Fig . 5.

The safety device 70 supports with its support collar 76 comprising a massive and rigid collar body 78 the sliders 90 as well as an actuating mechanism 82 comprising two cartridges 114a, 114b containing gas under a high pressure, e.g. 100 bar. The actuating mechanism 82 further comprises first gas leads 113 leading from the cartridges 114a, 114b to a solenoid shut-off valve 112 acting as trigger device for the actuating mechanism 82. Further, the actuating mechanism comprises second gas leads 111 leading from the shut-off valve 112 to distribution chambers 110 from which third gas leads 104 branch off which are connected to each slider, i.e. a cylinder 92 of each slider as it is shown in Fig. 5 . The emergency stop control 72 is connected with a backup energy supply 74 to be able to operate the trigger devices 112.

In Fig. 4 the cartridges 114, gas leads 111, 113, 104 as well as distribution chamber 110 and sliders 90 are shown open. It is clear that these components are encompassed in the massive collar body 78 which forms thick sealing walls for all these high-pressure subjected components.

Now the sliders 90 are explained in connection with Fig. 5. Each slider 90 comprises a cylinder 92 in which a piston 94 is movable in a direction perpendicular to the connecting faces 80 of the stator beam 18, forming the slider faces. The piston 94 carries at its front a sliding shoe 96 which is receiving a sliding pad 98 facing the connecting face 80 of the stator beam 18. The piston 94 is via a spring 100 biased in a retracted position which is defined by stoppers 102 in the cylinder 92. The cylinder 92 is connected with a first gas lead 104 so that a pressure room 106 is formed in the cylinder 92 on the back face 108 of the piston 94, which is limited on one hand by the inner faces of the cylinder 92 and on the other hand by the back side 108 of the piston.

The function of the safety device 70 of the elevator is as follows :

In case of mains power off, over-speed or in case of other safety relevant issues, the emergency stop control 72 operates the trigger device (solenoid valve) 112 so that from the cartridges 114a, 114b high-pressured gas is forwarded via the first gas leads 113, the open shut-off valve 112, second gas leads 111, the distribution chambers 110 to the third gas leads 104 which are connected with the cylinders 92 of the sliders 90. Thus the pressure chamber 106 in the cylinder 92 is put under high gas pressure pushing the piston 94 by its back face 108 and thus also the sliding shoe 96 together with the sliding pad 98 against the slide surface 80 of the stator beam 18 thus braking the elevator car 16 with a defined force, and maintaining the air gap between mover(s) and stator rail(s), so as to prevent an excessive deceleration which is possible when the air gap brakes down and the mover clutches to the stator beam because of the permanent magnets in the mover. Particularly relevant is this situation when the car is in upwards movement, so that the clutching and the gravitational force add up. Via the pistons the air gap is maintained and the deceleration is defined by the frictional forces between the sliders and the slide surfaces. This allows a high deceleration which maintain within the allowed range to avoid harm to passengers based on excessive deceleration, e.g . loosing floor contact.

Preferably, the kinetic/sliding friction coefficients of the sliding pads 98 and slide surfaces 80 are substantially low compared to conventional brake pads and brake surfaces, e.g. below 0,5.

The trigger device (shut-off valve ) 112 is operated by the emergency stop control 72, the emergency stop control 72 energizes the shut-off valve 112 as to open it, which leads to the above slider action. The trigger device 112 is operated by the emergency stop control 72 in case of over speed or other safety relevant items. Accordingly, a very strong and fast but defined braking action is achieved via this safety device 70. The emergency stop control 72 is connected with a backup energy supply 74 to be able to operate the trigger device 112 also in case of mains power-off.

It is clear that in case of a cartridge 114 containing explosives a detonator has to be energized by the emergency stop control instead or additionally to the shut-off valve 112, which detonator is preferably located in the cartridge. In this case the cartridge preferably is a one-way cartridge which has to be replaced after a detonation.

The invention is not restricted to the above-mentioned embodiments but can be carried out within the scope of the appended patent claims.

List of reference numbers

elevator

elevator shaft

elevator motor

elevator car

stator beam

fastening elements

shaft wall /shaft side

lower mover

upper mover

first guide rail

second guide rail

first car guide

second car guide

support structure

first side face

second side face

third side face

fourth side face

stator rail comprising stator teeth to co-act with the mover

counter face of mover with active parts of the mover as, irons, permanent magnets and windings

first arm of C-profile mover

second arm of C-profile mover

third arm of C-profile mover

fourth arm of C-profile mover

Opening of the mover profile

safety device

emergency stop control

backup energy supply

support collar

massive support collar body

connecting face - vertical side of the stator beam - slide surface

actuating mechanism

inner opening of the support collar

inner faces of the support collar facing the stator rails of the stator beam

slider

cylinder

piston

sliding shoe sliding pad

spring

stopper

third gas leads

pressure room in the cylinder

back face of the piston

distribution chambers

second gas leads

shut-off valve - solenoid valve - trigger device fist gas leads

cartridge with pressurized gas