WO2006059182A1

WO2006059182A1 - Device and process to rescue passengers trapped in an elevator car and elevator equipped therewith

Info

Publication number: WO2006059182A1
Application number: PCT/IB2004/003993
Authority: WO
Inventors: Frank Loeffler; Gérard Sirigu
Original assignee: Otis Elevator Company
Priority date: 2004-12-02
Filing date: 2004-12-02
Publication date: 2006-06-08

Abstract

The device to rescue passengers trapped in a stalled elevator car according to the invention is characterized in that it comprises means for disconnecting the power supply of the car drive motor and connecting it as a generator to brake any displacement of the car, means (5) for pulling the motor brake shoes, and hand wheel means (7) arranged at the end of the brake and motor shaft (43) in order to rotate the brake and motor shaft (43) as required if the car and counterweight loads stand at equilibrium, in viewing and controlling the rotating motion of said shaft until the car can be brought to a nearby landing and said passengers can be released.

Description

Device and process to rescue passengers trapped in an elevator car and elevator equipped therewith

This invention relates to a device and process to rescue passengers trapped in an elevator car and to an elevator equipped therewith.

Rescuing passengers trapped in an elevator car is known to be a difficult technical operation, which is normally carried out by an elevator service technician and is sometimes difficult when the weight of the car balances that of the counterweight.

In addition, the increasingly frequent use of motors without speed reducers creates a risk of car overspeed when the brake is released, which makes the operation hazardous. This invention aims at correcting these disadvantages and proposes a device to rescue passengers trapped in an elevator car, for instance a stalled elevator, characterized in that it comprises means for disconnecting the power supply of the car drive motor and connecting it as a generator to brake any displacement of the car, and means for pulling the motor brake shoes, in viewing and controlling the rotation of said shaft until the car can be brought to a nearby landing, and said passengers can be released.

The car drive motor is a motor equipped with a rotor and permanent magnets and without speed reducer, and the motor is converted into a generator by connecting the motor stator windings to themselves in series, and optionally with a determined electrical resistor.

The electrical resistor is selected according to the type of elevator and to the average car load, so that converting the motor into a generator ensures a regular displacement of the car drive at a defined and low speed.

The device includes advantageously a terminal comprised of motor connecting elements, a brake release tool and a mechanism that operatively connects the brake release tool and the terminal such that tool actuation must coincide with motor connection as a generator. The device further comprises a hand wheel means arranged at the end of the brake and motor shaft so as to rotate it as required if the car and counterweight loads are balanced.

Disconnecting the motor from the main power supply and connecting it as a generator is advantageously achieved via the terminal, i.e. a terminal box attached to the motor brake body, and a cover part covering the end of the brake body, mounted rotatably on the brake body and attached to the terminal box so that its connecting elements are translated when it rotates to disconnect the motor from its power supply and connect it as a generator in a rotated position. In the normal position, this cover part prevents said tool from accessing the brake shoes and the hand wheel from accessing the brake and motor shaft end, and frees the access upon rotation as soon as the motor is disconnected from its power supply and connected as a generator. This arrangement guarantees the safe operation of the device described above.

Said motor brake shoe pulling tool advantageously includes a fork attached to an actuating handle, which fork is hinged at each of its ends via an eccentric bearing on the brake body to a flat plate attached to a brake shoe by means of two connecting rods connected to the shoe and to the flat plate, wherein the assembly is symmetrical relative to the middle plane of the two eccentrics so that pulling on the handle causes an equivalent geared-down traction on each of the shoe connecting rods, through the eccentrics resting on the brake body, to lift the two brake shoes off the motor.

Said connecting rods are threaded rods screwed to the brake shoes via through-holes in the brake body and tightened by nuts against the flat plates.

In addition, the fork with the two flat plates and with the handle in the tilted operating position is sufficiently open between the two flat plates arranged on either side of the brake and engine shaft end to allow inserting the hand wheel between these two flat plates and down to the shaft end, wherein the operation of the handle to pull the shoes with the tool is not hindered by the hand wheel engaged with the brake and motor shaft end. furthermore the device includes a tool to pull the motor brake shoes, a hand wheel that can be engaged with the end of the brake and motor shaft and a cover rotatably mounted on the rear end part of the motor brake and mechanically attached to connecting elements of a motor connection box, wherein the cover connects the motor with the power supply in the central closed position of the rear brake body end and disconnects the motor from the power supply to connect it as a generator in the rotated position, thus exposing the rear part of the brake body to allow the tool to access the brake shoe and the hand wheel to access the end of the brake and motor shaft.

The invention also relates to the motor and the elevator fitted with the device described above.

This invention is illustrated below with an exemplary embodiment in relation with the appended drawings, in which:

Figures Ia and Ib are two schematic views of the rear end part of the motor brake, respectively showing the access cover in its closed service position and its open rescue access position.

Figures 2a and 2b are schematic drawings corresponding to Figures Ia and Ib and showing the motor connected with the power supply and connected as a generator.

Figure 3 is a perspective view of the brake shoe pulling tool, and Figure 4 is a perspective view of a complete embodiment of the device according to the invention.

The exemplary embodiment chosen is the most common case, that of an elevator with a machine room containing the drive motor for the elevator car. This machine room is easily accessible, as is the car drive motor.

We shall now assume that the elevator stalls and that the failure cannot be easily identified or repaired by the elevator maintenance technician and does not allow the car to be driven, while passengers are trapped inside. That may be a power outage. A technician must quickly come on site and first remove the passengers from the car. The device according to the embodiment, as described below, can be used to quickly release the trapped passengers, and the failure can then be searched for and repaired after the car has been opened.

The device according to the embodiment uses several elements (Figure 4) combined to ensure maximum safety during rescue, namely a terminal box 1 to connect the motor as a generator, a safety cover 3 for the rear brake body, protecting the access to the motor brake, a brake releasing tool 5 and a hand wheel 7 to actuate the motor and brake shaft.

The electrical motor is equipped with a permanent magnet rotor and a wound stator. The brake is mounted in line on the motor and engaged with the motor shaft. This kind of motor has a low rotary inertia and is unable to brake the displacement of the elevator car by itself.

The terminal box 1 can be mounted on the brake body 9 at the rear upper end thereof (Figure Ia). It comprises connecting elements 1 1 with mobile strips connecting the motor M to the main power supply at 13 (Figure 2a) or connecting it as a generator at 15 (Figure 2b) by connecting its stator windings 17 in series with an optional electrical resistor on each one of them (not represented), which resistor is calibrated to enable a braked displacement by the car motor at half load of the car, at a low and set speed.

The brake access cover 3 is rotatably mounted on the terminal box 1. It comprises a disc- shaped plate 19 covering the rear end part of the brake and attached to a rod 21 connected by an axis to the terminal box 1. It can rotate in order to prevent access to the rear end part of the brake in the normal service position (vertical position) (Figure Ia) and rotate perpendicular to the vertical position (Figure Ib) to uncover access to the rear end part of the brake. The rod 21 can be engaged by its axe with a motion return mechanism (not represented) rotating the connecting elements 11 in the terminal box. The cover 3 is actuated manually, and is locked in its both positions by an appropriate arresting device, e.g. an arresting claw 23 arresting the rod 21 in a position engaged with the terminal box 1. The arresting claw 23 locks the cover in a closed position in normal service to secure the access to the rear end part of the brake. The brake release tool 5 is designed to fit the rear end of the brake when the cover 3 is turned at right angles from its normal service position, while the motor is connected as a generator.

It comprises a fork 25 integral with an actuating handle 27. The fork 25 includes two identical double arms 29 linked each to an eccentric element 31 at its outer end and to a flat plate 33 hinged in its middle inward of the end. The eccentric 31 is properly mounted at the end of the fork, rotated to be adjusted on its axis so as to bear on the brake body 9, while the fork 25 is slightly pulled towards the vertical by its handle 27. The flat plates 33 are connected to the two motor brake shoes, each by means of two threaded rods 35 at its ends. These rods are screwed on the brake shoes and tightened by means of a nut 37 on the plate.

The assembly has a middle symmetry plane relative to the two eccentrics, so that pulling on the tool handle exerts, through the eccentrics 31 bearing on the rear brake body 9, an equivalent traction on each of the rods 35 of the plate (several hundred daN) to equally lift the two brake shoes and thus release the brake.

The hand wheel 7 is essentially made of an actuation disk 39 and a sleeve 41 attached coaxially with the disk. The end of the sleeve exhibits an hexagonal recess complementary, to within the engagement clearance, with the outstanding end 43 of the brake and motor shaft. The disk 39 has a peripheral crown 45 that can be seized manually and its outer surface is striated radially 47 to help view the speed of the motor shaft and thus the car drive speed.

The sleeve 41 of the hand wheel is designed to engage with the end of the shaft 43 held coaxially thereon, between the two flat plates 33 of the fork. This hand wheel 7, in addition to helping view the car drive speed, can also be rotated manually to bring the car to a nearby landing in the exceptional case of the loaded car and the counterweight being at equilibrium.

The operation of the device shall now be described. It can be inferred from the preceding description.

The safety cover must be turned at 90° from the vertical position by first removing its locking claw, then locking it with the claw in its position (Figure Ib). The motor is disconnected from its power supply and connected as a generator to brake its drive. The tool is then inclined (Figure 4) and applied at the end of the rear brake body and the flat plates 33 are connected to the brake shoes by means of said threaded rods 35, which are engaged and screwed into the brake body to the brake shoes and tightened on the flat plates by means of the upper nuts 37. The hand wheel 7 is then arranged on the shaft end 43 between the two flat plates 33. The device is then ready to operate, and it has taken only a few minutes to assemble. The handle 27 is then pulled slightly towards the shaft axis to release the brake and thus allow the natural displacement of the elevator car (except in the rare case of equilibrium mentioned above) up or down to the nearest landing, according to the load of the car relative to the counterweight. The car drive speed is reduced and its control is shown by the hand wheel. Motion control is ensured by an adjusted pulling of the tool so as to obtain the smoothest possible displacement. Upon approaching the landing, the operator is informed by a conventional car approach warning device on the landing, and particularly by a battery-powered lamp in this warning device.

The tool is then released. The brake is then tightened. The car doors can be opened manually and the passengers trapped in the car can be released.

The device can then be disassembled. The hand wheel is first removed, then the tool is removed from the rear brake body end by unscrewing the threaded rods from the brake shoes, and the cover is finally brought into its service position, and locked by the claw 23 to cover the rear brake body.

According to a variant of the invention, which is not represented and is designed for an elevator without machine room, wherein the motor is mounted on top of the shaft, it should be noted that the tool 5 could be fixed in a reduced form on the rear brake body, without the access cover. The connecting elements 11 of the terminal box are actuated to connect the motor as a generator at the same time as the tool is actuated, e.g. with an appropriate return mechanism connected to the actuation means, wherein the tool is actuated to release the motor brake by a cable with an actuation handle protected in a locked box that also bears a car approach warning light for a landing and a display of the motor speed obtained by measuring the generator current.

Claims

1. Device to rescue passengers trapped in a stalled elevator car, characterized in that it comprises means for disconnecting the power supply of the car drive motor and connecting it as a generator ( 15) to brake any displacement of the car, and means (5) for pulling the motor brake shoes, in viewing and controlling the rotating motion of said shaft until the car can be brought to a nearby landing and said passengers can be released.

2. Device as per claim 1 , characterized in that the car drive motor is a motor with permanent magnets and without speed reducer, and the motor is converted into a generator by connecting the motor stator windings (17) to themselves in series, optionally with a determined electrical resistor.

3. Device as per claim 2, characterized in that said electrical resistor is selected according to the type of elevator and to the average car load, so that converting the motor into a generator ensures a regular displacement of the car drive at a defined and low speed.

4. Device as per claim 1, characterized in that said means for disconnecting/ connecting is provided in a terminal comprised of motor connecting elements, and said means for pulling includes a brake release tool _} wherein the brake release tool and the terminal are operatively connected such that tool actuation must coincide with motor connection as a generator.

5. Device as per claim 1, characterized in that said means for disconnecting/ connecting is provided in a terminal comprised of a terminal box (1) attached to the motor brake body (9), and said means for pulling includes a brake release tool (5), and further comprising a hand wheel (7) mounted at the end of the brake and motor shaft to rotate it if required, and a cover part (3) mechanically bound to said terminal and covering the end of the brake body (9), mounted rotatably on the terminal box (1) so that its connecting elements (11) are translated when it rotates to disconnect the motor from its power supply and connect it as a generator in a rotated position, wherein this cover part (3) in the normal position prevents said tool (5) from accessing the brake shoes and the hand wheel (7) from accessing the brake and motor shaft end (43), and frees the access upon rotation as soon as the motor is disconnected from its power supply and connected as a generator.

6. Device as per claim 5, characterized in that said brake release tool (5) comprises a fork (25) attached to an actuating handle (27), which fork (25) is hinged at each of its ends and via an eccentric (31) bearing on the brake body (9) to a flat plate (33) attached to a brake shoe by means of two connecting rods (35) connected to the shoe and to the flat plate (33), wherein the assembly is symmetrical relative to the two eccentrics (31) so that pulling on the handle (27) of the tool causes an equivalent geared-down traction on each of the shoe connecting rods (35) to lift the two brake shoes off the motor.

7. Device as per claim 6, characterized in that said connecting rods (35) are threaded rods screwed to the brake shoes via through- holes in the brake body (9) and tightened by nuts (37) against the flat plates (33).

8. Device as per claim 6 - 7, characterized in that the fork (25) with the two flat plates (33) and with the handle in the tilted operating position is sufficiently open between the two flat plates (33) arranged on either side of the brake and engine shaft end (43) to allow inserting the hand wheel (7) between these two flat plates (33) and down to the shaft end (43), wherein the operation of the handle (27) to pull the shoes with the tool (5) is not hindered by the hand wheel (7) engaged with the brake and motor shaft end (43).

9. Device as per claims 5 - 8, characterized in that the hand wheel (7) is essentially made of an actuation disk (39) and a sleeve (41) attached coaxially with the disk, wherein the end of the sleeve exhibits an hexagonal recess complementary, to within the engagement clearance, with the outstanding end (43) of the brake and motor shaft, and the disk (39) also has a peripheral crown (45) that can be seized manually and its outer surface is striated radially (47) to help view the speed of the motor shaft and thus the car drive speed.

10. Device as per claim 1, characterized in that it comprises several elements combined to ensure maximum safety during rescue, namely a terminal box (1) with connecting elements (11) to connect the motor as a generator, wherein said motor can be an electrical motor with a permanent magnet rotor and a wound stator without speed reducer, a safety cover (3) protecting the access to the motor brake, rotatably mounted on the rear end part of the brake body (9) and mechanically attached to the connecting ^'■•elements (11) of the motor connection box ( 1), a brake releasing tool (5) to pull the motor brake shoes and a hand wheel (7) that can be engaged with the end of the brake and motor shaft (43) to actuate the motor and brake shaft, wherein the cover (3) connects the motor with the power supply in the central closed position of the rear brake body end (9) and disconnects the motor from the power supply to connect it as a generator in the rotated position, thus exposing the rear part of the brake body (9) to allow the tool (5) to access the brake shoes and the hand wheel (7) to access the end of the brake and motor shaft (43) .

1 1. Device as per claims 1- 10, characterized in that it is designed for an elevator without machine room, wherein the motor is mounted on top of the shaft, and the tool (5) is fixed in a reduced form on the rear brake body (9), without the access cover, the connecting elements (1 1) of the terminal box (1) being actuated to connect the motor as a generator at the same time as the tool (5) is actuated with an appropriate motion return mechanism, wherein the tool (5) is actuated to release the motor brake by a cable with an actuation handle protected in a locked box that also bears a car approach warning light for a landing and a display of the motor speed obtained by measuring the generator current.

12. Process for operation of the device as per claim 1 - 11 including the following successive steps: - switching the motor supply from powered mode to generator mode to brake its drive ; pulling the motor brake shoes for releasing the motor brake, and controlling the motion until the car be brought to a nearby landing where the passengers can be released.

13. Process as per claim 12 further comprising the step of arranging a hand wheel means (7) at the end of the brake and motor shaft (43) in order to rotate the brake and motor shaft (43) as required if the car and counterweight loads stand at equilibrium.

14. Process as per claiml3 including the following successive steps : - the safety cover (3) must be turned at 90° from the vertical position and locked in position with the claw (23)in its position, while the motor is disconnected from its power supply and connected as a generator to brake its drive; - the tool (5) is then inclined and applied at the end of the rear brake body (9) and the flat plates (33) are connected to the brake shoes by means of said threaded rods (35), which have first been engaged and screwed into the brake body, to the brake shoes and tightened on the flat plates (33) by means of upper nuts (37); - the hand wheel (7) is then arranged on the shaft end (43) between the two flat plates (33), and the device is then ready to operate;

- the handle (27) is then pulled slightly towards the shaft axis to release the brake and thus allow the natural displacement of the elevator car up or down to the nearest landing, according to the load of the car relative to the counterweight, wherein the car drive speed is shown by the hand wheel (7) and motion control is ensured by an adjusted pulling of the tool (5) so as to obtain the smoothest possible displacement., and the operator is informed when approaching the landing by a conventional car approach warning device on the landing, and particularly by a lamp in this warning device;

- the tool is then released and the brake is then tightened;

- the car doors are then opened manually and the passengers trapped in the car can be released.

15. Elevator car drive motor characterized in that it is fit to accommodate a passenger rescue device as per any one of claims 1 - 11.

16. Elevator characterized in that it is equipped with a passenger rescue device as per any one of claims 1 - 11.