EP1799602A1

EP1799602A1 - Device for the safety stop of an elevator car

Info

Publication number: EP1799602A1
Application number: EP04769540A
Authority: EP
Inventors: Gérard Sirigu; Dominique Goulet; Pascal Rebillard; Nicolas Fonteneau; Julien Dos Reis; Olivier Dukacz; Jean-Noël CLOUX; Bernard Picquenot
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2007-06-27
Also published as: JP4664370B2; JP2008514527A; WO2006035264A1; CN101027239A

Abstract

The device (1) according to the invention for the safety stop of an elevator car (3), particularly in elevators without machine room and with a small free space at the top (4) and/or bottom (6) of the shaft in normal operation, is characterized in that it includes at least one box (9, 9') mounted relative to the shaft and level with the speed limiting cable (5) of the car overspeed safety device and provided with an articulated fork element (15, 15') that has an end adapted to engage at least one attachment element (21, 23) tied to said speed limiting cable (5) of the car overspeed safety device (7) in the service position of the device to arrest the cable and thus cause a safety stop of the elevator car (3), and to be disengaged from said attachment element (21, 23) ,in the inactive position, wherein said fork element (15) in the service position and the cable attachment element (21, 23) are located at an appropriate height in combination with each other in the elevator shaft for the engagement of the attachment element (21, 23) with the fork element (15) to cause the arrest of the elevator car at an adequate height in the shaft to leave at least a safety space for the operator on the cabin roof (37) or in the shaft bottom (6).

Description

DEVICE FORTHESAFETYSTOPOFAN ELEVATORCAR

This invention relates to a device for the safety stop of an elevator car, particularly in elevators without machine room, and an elevator equipped therewith.

Elevators with no machine room and a reduced space at the top, and possibly at the bottom, of the shaft are known to require additional measures to maintain a safety space above the car, particularly for maintenance technicians working on the cabin roof. To achieve this, mechanical car arresting devices are known, comprising a device with a rod that is manually extended towards a stop at a defined height, limiting a safety space for the maintenance technician on the cabin roof. However, this type of device produces high and harmful abutment stresses on the elevator structure.

This invention aims at correcting these disadvantages and proposes a device for the safety stop of an elevator car, particularly in elevators without machine room and with a small free space at the top and/or bottom of the shaft in normal operation, characterized in that it includes at least one box mounted relative to the shaft and level with the speed limiting cable of the car overspeed safety device and provided with an articulated fork element that has an end adapted to engage at least one attachment element tied to said speed limiting cable of the car overspeed safety device in the service position of the device to arrest the cable and thus cause a safety stop of the elevator car, and to be disengaged from said attachment element in the inactive position, wherein said fork element in the service position and the cable attachment element are located at an appropriate height in combination with each other in the elevator shaft for the engagement of the attachment element with the fork element to cause the arrest of the elevator car at an adequate height in the shaft to leave at least a safety space for the operator on the cabin roof or in the shaft bottom.

Said attachment element is advantageously shaped as an olive, but any rigid element forming a protrusion that can engage the end of the fork element may be appropriate.

Said box may be mounted so as to slide vertically relative to the shaft on a small height, being returned by a spring at a reference height in the shaft; however, the fork element is advantageously mounted so as to slide vertically in the box, e.g. on two vertical posts, to be returned by a spring at a reference height, in order to compensate for the differences in the stopping distance of the car and thus of the speed limiting cable attached thereto. This sliding height of the box or of the supporting element of the fork element is slightly greater than the longest safety stopping distance of the car. The safety space for the operator on the cabin roof takes this longer stopping distance of the car into account. Thus the height of the safety space in the shaft corresponds to the height of engagement of the attachment element on the cable with the fork element plus the longest car stopping distance. The service position of the device is obtained as soon as the operator accesses the cabin roof, either by directly actuating an activation switch to inspect the elevator or automatically as soon as a landing door opens, using a safety service switch embedded in the lock thereof or activated when the door opens.

Said fork element is a longitudinal plate that can be e.g. rectangular and is hinged with a motor drive in the plane of the box, having a slit end, preferably flared outwards, to receive said speed limiting cable with a small clearance and engage with said attachment element.

Said box comprises a vertical passage for the speed limiting cable formed by an appropriate cutout in its construction walls. Said fork element is brought into the service position by an electromagnet with an adequate power supply to move the fork element towards the limiting cable and receive it at its end shaped as a fork or a flared slot and disengage it in the inactive position of the device.

Said fork element is advantageously hinged with a back mass opposite the fork end relative to its articulation axis, so that in operation, it comes into a natural engagement position with the speed limiting cable in a horizontal position, abutting on the actuating element of the non-powered electromagnet, and is disengaged from the limiting cable in an inclined position when inactive, under the thrust of the actuating element of the electromagnet, which is powered by a switch located slightly downstream of the safety area, e.g. a limit switch for inspection, wherein said electromagnet is actuated in normal operation as the car comes into the safety area of the shaft. With this arrangement, the electromagnet does not have to be powered except during this upper safety course, the electromagnet can be operated and any blocking avoided, and the device naturally returns into the safety position in case of power failure.

Of course, the device may include other attachment elements, e.g. a second attachment element located slightly lower than the first one, with a greater safety distance from the cabin roof to the shaft ceiling, according to the provided standards, wherein the device has a double upper safety in this case. Similarly, the device may be fitted with at least one attachment element in a lower safety area of the shaft, at the bottom, to prevent an operator being crushed by the elevator car overspeed in the shaft bottom.

The invention also relates to an elevator equipped with a car safety stopping device as defined above.

The invention is illustrated hereafter by an exemplary embodiment, referring to the appended drawing in which: Figure 1 is a schematic elevation view of an elevator equipped with a device according to the invention;

Figure 2 shows the box of the device according to the invention in the inactive position;

Figure 3 shows the box in the service position; and Figure 4 shows the box when the elevator car is stopped, with its springs compressed.

Referring to the drawings, and particularly to Figure 1 , the safety stopping device

1 for an elevator car 3 according to this illustrated embodiment is fitted to an elevator with a small residual space at the top and the bottom of the shaft. This device allows keeping a safety space for the maintenance technician both at the top 4 and at the bottom 6 of the shaft.

The device involves the speed limiting cable 5 of the car overspeed safety device 7, which operates both during ascension and descent of the car.

It includes two boxes to control the safety stop of the car, one 9 for the top of the shaft and the other 9' for the bottom thereof. These boxes 9, 9' are identical and arranged level with the speed limiting cable 5 of the car safety device, which they accommodate in a cable passage 1 1 formed by an appropriate cutouts in their upper and lower walls. They are directly attached to the wall 13 of the shaft, possibly with a cross member, or to a car guide rail with an appropriate supporting element. each of the boxes 9, 9' is provided with a fork element 15, 15' hinged inside the box and in its plane. This fork element 15, 15' is shaped as a rectangular plate and has a fork-shaped end 17 with an outward flaring slot turned towards the inside of the box.

This fork end is adapted to receive the speed limiting cable 5 with a clearance when the fork element is brought into the horizontal service position (Figure 3) and to disengage therefrom when the fork element is driven into its tilted inactive position (Figure 2) by a bottom electromagnet 19 mounted in the box. The speed limiting cable 5 is provided with two olive-shaped attachment elements

21 , 23 protruding on the cable 5 and adapted to engage with the fork-shaped end 17 of the fork element when it is in the horizontal service position. This engagement of the olive with the fork causes a tug on the cable 5, the actuation of the overspeed safety device 7 and thus the safety stop of the car 5. Each of the fork elements 15, 15' of the boxes is provided with a mass opposite the fork-shaped end 17, which naturally brings it into a horizontal position, abutting on an upper abutment element 27 with its fork-shaped end 17 and resting with its opposite end on the pusher element 29 of the bottom electromagnet 19. Said electromagnet 19, when powered, pushes the fork element 15 into its tilted position with its pusher element 29 and drives it away from the speed limiting cable 5. The fork element 15 and the electromagnet 19 are mounted on a support 31 that is mobile vertically, sliding along two lateral vertical posts 33 attached to the box. This support 31 is maintained in its low position with an elastic return by two identical helical springs 35 inserted over the upper part of a post 33, between the upper wall of the box and an appropriate fold of the support.

The sliding travel of the support 31 in the box is designed up to a maximum value of 50cm, which corresponds to the longest stopping distance of the speed limiting cable 5 by the safety device 7 and therefore of the elevator car 3 to which it is attached by a connecting lever 34. In the inspection mode, when the car travels at low speed (approximately 0.3m per second), the car is stopped over a distance of about 2-3cm, with a short displacement of the support 31 in the box by the same distance, and thus a low compression of the return springs 35 (Figure 4). The speed limiting cable presents two said olives spaced apart from each other, one upper olive 23 controlling the stopping of the car with a minimum safety space of at least one meter in height between the car roof 37 and the shaft ceiling 4, and a lower olive 21 controlling the stopping of the car with a larger safety space, where the operator can stand upright on the cabin roof 37 and there is therefore a free height of about two meters between the car roof 37 and the shaft ceiling 4.

The upper safety stop control box 9 is arranged at a defined height in the shaft relative to said olives 21, 23 on the speed limiting cable 5, so that the stop control of the fork element 15 by each of the olives provides said safety spaces taking account of its sliding displacement in the box.

The lower box 9' operates in relation with the lower olive 21 as it is at an appropriate height in the shaft to provide a safety space for the operator at shaft bottom 6, with a height of e.g. 0.50m between the car bottom 39 and the shaft bottom 6.

Each of the upper 9 and lower 9' boxes operates in relation with an inspection limit switch, respectively an upper switch 41 mounted on the cabin roof and a lower switch 43 mounted on the cabin bottom 39. The upper switch 41 comprises a mobile lever 45 with a lateral wheel attached to the cabin roof 37 and resting with a spring on a vertical longitudinal cam 47 attached to the elevator shaft. The lever 45 resting on the cam 47 corresponds to the closed circuit position in which the electromagnet is powered in normal operation and tilts the fork element 15 to disengage it from the speed limiting cable 5. When the switch is not in contact with the cam 47, the circuit is open and the fork element 15 can then return to the horizontal service position of the device.

Similarly, the lower switch 43 comprises a lower wheel lever 49 that cooperates with a lower vertical longitudinal cam 51 on the shaft to close the electromagnet circuit when resting on the cam and open it when not in contact.

The function of the boxes is also controlled by a main inspection switch actuated by the operator before inspection (not represented) and by a series of landing door opening safety switches in the elevator (not represented) that activate the safety device as soon as any landing door of the elevator is opened. The switches can be mounted in series in the box control circuit.

The operation of the device shall now be described and easily understood on the basis of the description below. The maintenance operator pushes the main inspection switch. The safety device 1 is then activated, which deactivates the electromagnet 19 on each of the upper 9 and lower 9' boxes over the entire length of travel of the car 3, and the fork element 15 engages the speed limiting cable 5. The car travels at low speed (approximately 0.3m/s). At the end of the inspection travel, the limit switch 41 or 43 opens the elevator control circuit and the car stops. The safety device 1 is triggered only if this procedure is executed with an anomaly; if the car continues to move, e.g. upwards, the fork element 15 of the upper box catches the lower olive 21 of the safety device cable to trigger that device and arrest the car at the first safety barrier of the device, thus providing a space about 2m high between the cabin roof 37 and the shaft ceiling 4. If the lower olive 21 is accidentally missed, the upper olive 23 is caught by the fork element 15 and ensures the second safety barrier to provide the minimum safety space for the operator.

After the maintenance operation has been performed, and as soon as the main inspection switch is deactivated and all elevator landing doors are closed, the device 1 returns to normal elevator operation as described above, with the electromagnet 19 that drives the fork element 15 being powered only when the elevator car enters the upper and lower parts of the shaft.

It should be noted that the fork element in the device may also directly engage the lever of the overspeed safety device to arrest the elevator car.

Claims

1. Device (1) for the safety stop of an elevator car (3), particularly in elevators without machine room and with a small free space at the top (4) and/or bottom (6) of the shaft in normal operation, characterized in that it includes at least one box (9, 9') mounted relative to the shaft and level with the speed limiting cable (5) of the car overspeed safety device and provided with an articulated fork element (15, 15') that has an end (17) adapted to engage at least one attachment element (21 , 23) tied to said speed limiting cable (5) of the car overspeed safety device (7) in the service position of the device to arrest the cable and thus cause a safety stop of the elevator car (3), and to be disengaged from said attachment element (21, 23) in the inactive position, wherein said fork element (15) in the service position and the cable attachment element (21, 23) are located at an appropriate height in combination with each other in the elevator shaft for the engagement of the attachment element (21, 23) with the fork element (15) to cause the arrest of the elevator car at an adequate height in the shaft to leave at least a safety space for the operator on the cabin roof (37) or in the shaft bottom (6).

2. Device as per claim 1, characterized in that said attachment element (21 , 23) is shaped as an olive or is any rigid element forming a protrusion that can engage the end (17) of the fork element (15).

3. Device as per any one of claims 1 and 2, characterized in that said box (9, 9') is mounted so as to slide vertically relative to the shaft, being returned by a spring (35) at a reference height in the shaft, in order to compensate for the differences in the stopping distance of the car (3) and thus of the speed limiting cable (5) attached thereto.

4. Device as per any one of claims 1 and 2, characterized in that the support (31) of the fork element (15, 15') is mounted so as to slide vertically in the box (9, 9'), to be returned by a spring (35) at a reference height in the shaft, in order to compensate for the differences in the stopping distance of the car (3) and thus of the speed limiting cable (5) attached thereto.

5. Device as per any one of claims 3 and 4, characterized in that the sliding height of the box (9, 9') or of said supporting element (31) of the fork element is slightly greater than the longest safety stopping distance of the car (3), and the safety space for the operator on the cabin roof takes this longer stopping distance of the car (3) into account.

6. Device as per any one of the preceding claims, characterized in that the service position of the device is obtained as soon as the operator accesses the cabin roof (37), either by directly actuating an activation switch to inspect the elevator or automatically as soon as a landing door opens, using a safety service switch embedded in the lock thereof or activated when the door opens.

7. Device as per any one of the preceding claims, characterized in that said fork element (15, 15') is a longitudinal rectangular plate hinged with a motor drive (19) in the plane of the box (9, 9'), having a slit end (17), preferably flared outwards, to receive said speed limiting cable (5) with a small clearance and engage with said attachment element (21 , 23).

8. Device as per claim 7, characterized in that said fork element (15, 15') is brought into the service position by an electromagnet (19) with an adequate power supply to move the fork element (15) towards the limiting cable (5) and receive it at its fork-shaped end (17), and disengage it in the inactive position of the device.

9. Device as per claim 7, characterized in that said fork element (15, 15') is hinged with a back mass (25) opposite the fork end (17) relative to its articulation axis, so that in operation, it comes into a natural engagement position with the speed limiting cable (5) in a horizontal position, resting on the actuating element (29) of the non-powered electromagnet (19), and is disengaged from the limiting cable (5) in an inclined position when inactive, under the thrust of the actuating element (29) of the electromagnet (19), which is powered by a switch (41 , 43) located slightly downstream of the safety area, e.g. a limit switch for inspection, wherein said electromagnet (19) is actuated in normal operation as the car (3) comes into the safety area of the shaft.

10. Device as per any one of the preceding claims, characterized in that said box (9, 9') comprises a vertical passage (1 1 ) for the speed limiting cable (5) formed by an appropriate cutout in its construction walls.

1 1. Device according to any one of the preceding claims, characterized in that it includes a second attachment element (21) located slightly lower than the first one (23), with a greater safety distance from the cabin roof (37) to the shaft ceiling (4), according to the provided standards, wherein the device has a double safety in this case.

12. Device as per any one of the preceding claims, characterized in that it is fitted with at least one attachment element in a lower safety area of the shaft, at the bottom, to prevent an operator being crushed by the elevator car in the shaft bottom (6).

13. Device as per any one of the preceding claims, characterized in that it involves a double direction speed limiting cable (5) of the car overspeed safety device to stop the elevator car both during ascension and descent, and includes two boxes (9, 9') to control the safety stop of the car, one (9) for the top of the shaft and the other (9') for the bottom thereof, each providing at least a safety space for an operator respectively at the top (4) and at the bottom (6) of the shaft.

14. Device as per claim 13, characterized in that each of the upper (9) and lower (9') boxes operates in relation with an inspection limit switch, respectively an upper switch (41) mounted on the cabin roof (37) and a lower switch (43) mounted on the cabin bottom (39), wherein the upper switch (41) comprises a mobile lever (45) with a lateral wheel attached to the cabin roof (37) and resting with a spring on a vertical longitudinal cam (47) attached to the elevator shaft in the closed circuit position in order to power the electromagnet (19) in normal elevator position to tilt the fork element (15) in order to disengage it from the speed limiting cable (5) and leaving contact with the cam (47) to open the circuit and allow the fork element (15) to return to the horizontal service position of the device, and wherein, similarly, the lower switch (43) comprises a lower wheel lever (49) that cooperates with a lower vertical longitudinal cam (51 ) on the shaft to close the electromagnet circuit (19) when resting on the cam and open it when not in contact.

15. Device as per any one of claims 1 , 3-6, characterized in that the fork element (15, 15') directly engages the lever of the overspeed safety device (7) to arrest the elevator car (3).

16. Elevator characterized in that it is fitted with a car safety stop control device (1) as per any one of the preceding claims.