WO2000078660A1

WO2000078660A1 - Emergency rope brake device for elevator systems

Info

Publication number: WO2000078660A1
Application number: PCT/KR1999/000321
Authority: WO
Inventors: In-Su Oh; Jun-Ki Pyeon
Original assignee: Kisan Information System Corp.
Priority date: 1999-06-19
Filing date: 1999-06-19
Publication date: 2000-12-28

Abstract

An emergency rope break device, designed to be selectively operated in an occurrence of an abnormal operation of an elevator system, is disclosed. In the device, an oil pressure generating unit pressurizes actuating oil under the control of a control unit. A reaction unit (1) is operated by the pressurized oil and generates a reaction force. A rope locking unit (2) is operated in conjunction with the reaction unit to lock the ropes (R) in an occurrence of such an abnormal operation of the elevator system. In the reaction unit (1), a cylinder actuator is fixed to a support plate, with a plurality of bolt members fixed to the support plate and a compression coil spring fitted over each of the bolt members. In the rope locking unit (2), a fixed plate is positioned in parallel to the support plate with the bolt members movably and perpendicularly passing through the fixed plate.

Description

EMERGENCY ROPE BRAKE DEVICE FOR ELEVATOR SYSTEMS

Technical Field

The present invention relates, in general, to a rope brake device for elevator systems and, more particularly, to an emergency rope brake device for elevator systems, the device being designed to selectively and hydraulically operate a movable plate provided with a brake lining having semicircular or trapezoidal cross-sectioned locking grooves, thus firmly locking and stopping the driving ropes of the elevator car in the case of an occurrence of emergency where the elevator car unexpectedly slips down due to a rope slip during a temporary stop mode of the elevator car or moves up and down at an abnormal high speed exceeding a preset normal speed due to, for example, a breakage of worm and worm gear or a breakage of a main brake unit of the elevator system, the emergency rope brake device thus finally accomplishing a desired operational safety of elevator systems.

Background Art

As well known to those skilled in the art, elevator systems are equipment installed in tall buildings and used for carrying people or goods up and down in the buildings. In such an elevator system, an elevator car is movably set in an elevator shaft, having a rectangular cross-section, of a building and is hung on the motor- operated suspension ropes, with a guide shoe being mounted at each exterior sidewall of the car and movably engaging with a vertical guide rail within the shaft. The elevator car is thus smoothly moved from one level to another in the building. During such a movement of the elevator car within the shaft, the guide shoes of the car are guided by the guide rails, thus allowing the elevator car to be moved without having any lateral movement in the shaft. In order to use such an elevator car, a user pushes a desired one of a plurality of floor number buttons of an indoor control panel set in the elevator car or pushes an up or down button of an outdoor control panel installed on a wall positioned around the shaft within the elevator area of a building. Upon pushing a desired button as described above, the control unit of the elevator system receives a signal from that button and lets the elevator car stop at a designated floor of the building. In order to allow the elevator car to be stopped at such a designated floor, the elevator system is provided with a main brake unit. On the other hand, such elevator systems may be abnormally operated due to a reduction in the braking force of the main brake unit, a reduction in the frictional force between the suspension ropes and the rope pulleys, or a difference in weight between the elevator car and a balance weight. In such a case, the elevator car may fail to be firmly stopped at a designated floor, but slip down at a time a user goes into or out of the car. The elevator car, with such abnormal conditions of the parts, may be rapidly moved up or down in the shaft at an exceedingly high speed. This may cause safety hazards. In order to prevent the elevator system from such an abnormal operation, an emergency rope brake device, designed to firmly lock and stop the suspension ropes when necessary, is added to the elevator system.

Several types of emergency rope brake devices for elevator systems have been proposed and used. One example of such known emergency rope brake devices is a wedge-type device. In such a wedge-type brake device, a wedge-shaped jaw engages with the guide rail of the shaft and is used as a means for controlling such an abnormal operation of the elevator systems. When an abnormal operation occurs in an elevator system, a governor of the wedge-type brake device senses an abnormal speed of the elevator car and makes a governor switch turn off the drive motor for the elevator system while locking and stopping a governor rope. The rope brake device, thereafter, locks the guide rails of the shaft, thus stopping the elevator car. However, such a wedge-type brake device is designed to operate only when the elevator car is moved down at an exceedingly high speed. Therefore, the device is not operated when the elevator car slips down or is rapidly moved up in the shaft at an exceedingly high speed. In an effort to overcome the above-mentioned problem, a solenoid-type emergency rope brake device has been proposed. In the brake device, a cylinder rod is normally retained at a locked position by a solenoid valve. When an abnormal operation occurs in the elevator system, the solenoid valve receives an abnormal signal prior to releasing the cylinder rod. The released cylinder rod is biased by the restoring force of a spring, thus pulling the brake shoe and bringing the brake shoe into contact with the ropes. The elevator car is thus stably and safely stopped. However, such a solenoid-type device is designed to maintain a braking pressure of not less than 1000 Kg, and so the device is problematic in that it is large-scaled and increases the production cost of such brake devices. Therefore, the solenoid-type emergency rope brake device for elevator systems is not practically used.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an emergency rope brake device for elevator systems, which is designed to be selectively operated in an occurrence of an abnormal operation of the elevator system wherein the elevator car undesirably slips down during a temporary stop mode or is rapidly moved up or down in the shaft at an exceedingly high speed during a moving mode due to a breakage or a malfunction of a main brake unit, and which thus firmly locks and stops the suspension ropes of the elevator system while almost completely preventing safety hazards of the elevator system and thereby accomplishes a desired operational safety of elevator systems.

In order to accomplish the above object, the present invention provides an emergency rope brake device for elevator systems, comprising: an oil pressure generating unit operated in response to a control signal output from a control unit of the elevator system, thus pressurizing actuating oil; a reaction unit operated by the oil under pressure from the oil pressure generating unit while generating a reaction force; and a rope locking unit operated in conjunction with the reaction unit, thus selectively locking the ropes in an occurrence of an abnormal operation of the elevator system.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Figs, la and lb are views, showing the position of an emergency rope brake device for elevator systems in accordance with this invention, in which:

Fig. la shows the device mounted to the motor- operated suspension ropes at a position where the ropes are connected to an elevator car; and

Fig. lb shows the device mounted to the ropes at a position where the ropes are connected to a balance weight;

Figs. 2a and 2b are perspective views of emergency rope brake devices in accordance with two different embodiments of this invention, in which:

Fig. 2a shows a first type of device designed to lock the ropes using one movable plate and one fixed plate; and Fig. 2b shows a second type of device designed to lock the ropes using two movable plates;

Figs. 3a and 3b are plan views, showing the operation of the first-type device of Fig. 2a, in which: Fig. 3a shows the device while releasing the ropes; and

Fig. 3b shows the device while locking the ropes;

Figs. 4a and 4b are plan views, showing the operation of the second-type device of Fig. 2b, in which: Fig. 4a shows the device while releasing the ropes; and

Fig. 4b shows the device while locking the ropes;

Figs. 5a and 5b are perspective views of brake linings used in the emergency rope brake devices of Figs. 2a and 2b, respectively, in which:

Fig. 5a shows a plurality of semicircular cross- sectioned locking grooves longitudinally formed on the brake lining for the fixed and movable plates of the first-type device; and

Fig. 5b shows a plurality of trapezoidal cross- sectioned locking grooves longitudinally formed on the brake lining for the second movable plate of the second- type device, and a concave locking groove formed along each of a plurality of longitudinal locking ribs on the brake lining for the first movable plate of said device; and Fig. 6 is a circuit diagram of a hydraulic circuit used for actuating a movable plate of the device according to this invention.

Best Mode for Carrying Out the Invention

Figs, la and lb are views, showing the position of an emergency rope brake device for elevator systems in accordance with this invention. In the drawings, the elevator car, the motor-operated suspension ropes, the emergency rope brake device, the rope pulley and the balance weight are designated by the reference characters "a", "R", "A", "b", and "p", respectively. In the elevator system, the rope "R" is wrapped around the pulley "b", with one end of the rope being connected to the elevator car and the other end being connected to the balance weight. In the embodiment of Fig. la, the emergency rope brake device "A" is installed on the ropes "R" at a position where the ropes are connected to the elevator car "a"

On the other hand, in the embodiment of Fig. lb, the device "A" has the same construction as that of the device of Fig. la, but is installed on the ropes "R" at a position where the ropes are connected to the balance weight "p" . Figs. 2a and 2b are perspective views of emergency rope brake devices in accordance with two different embodiments of this invention. In the first type of device of Fig. 2a, the rope locking unit 2 uses one movable plate and one fixed plate while locking the ropes. On the other hand, in the second type of device of Fig. 2b, the rope locking unit 2 locks the ropes using two movable plates. As shown in the drawings, the emergency rope brake device of this invention comprises a frame "F", a reaction unit 1, a rope locking unit 2 and an oil pressure generating unit 3. The reaction unit 1 is operated by a hydraulic pressure which is applied to a cylinder actuator 15 of the unit 1 from an oil pressure generating unit of a hydraulic circuit in response to a control signal output from a control unit. In a brief description, the rope locking unit 2 is hydraulically operated while locking or releasing the ropes "R".

Figs. 3a and 3b are plan views, showing the operation of the first-type device provided with one fixed plate 20 and one movable plate 22. That is, Fig. 3a shows the device while releasing the ropes. Fig. 3b shows the device while locking the ropes. As shown in the drawings, the frame "F" is a member having an H-shaped cross-section, with the fixed plate 20 perpendicularly meeting two mounts 88 at both ends thereof. The reaction unit 1 comprises a plurality of bolt members 10, a support plate 13 and a hydraulic cylinder actuator 15. The above bolt members 10 perpendicularly pass through both the support plate 13 and the movable plate 22 at corners of the two plates 13 and 22 prior to being tightened by nuts outside the two plates 13 and 22. In such a case, the fixed plate 20 is positioned between the two plates 13 and 22. A compression coil spring 12 is fitted over each of the bolt members 10 at a position between the fixed plate 20 and the movable plate 22. The support plate 13 is set in the device at a position outside the fixed plate 20 in a way such that the plate 13 is positioned in parallel to the fixed plate 20. The above support plate 13 has an opening at which the cylinder actuator 15 is mounted to the support plate 13. An actuation plunger 16, set in the cylinder actuator 15, is hydraulically movable in opposite directions relative to the fixed cylinder casing of the actuator 15. One end of the plunger 16 is brought into contact with the fixed plate 20. In the rope locking unit 2 of the first-type device, the fixed plate 20 and the movable plate 22 are arranged in parallel to each other while being normally biased in opposite directions by the compression coil springs 12. The two plates 20 and 22 are thus normally spaced out while forming a gap between them. The two plates 20 and 22 individually have a flat brake lining 23, 24 on the locking surface. A plurality of rope locking grooves 23a, 24a, having a predetermined depth, are longitudinally and parallely formed on the locking surface of the two linings 23 and 24. At the locking grooves 23a and 24, the brake linings 23 and 24 of the two plates 20 and 22 frictionally catch the ropes and lock the ropes when an abnormal operation occurs in the elevator system.

Figs. 5a and 5b are perspective views of brake linings used in the emergency rope brake device of this invention. As shown in Fig. 5a, the locking grooves 23a and 24a, formed on the brake linings 23 and 24 for the first-type device of Fig. 2a, have a semicircular cross- section. On the other hand, the locking grooves 23a, longitudinally formed on the brake lining 23 for the second movable plate 22 of the second-type device of Fig. 2b, have a trapezoidal cross-section as shown in Fig. 5b. The brake lining 24 for the first movable plate 21 of the second-type device has a plurality of longitudinal locking ribs with a concave locking groove 24a being formed along the top surface of each locking rib. Such a specifically designed configuration of the locking grooves 23a and 24a provides a wedging effect for the ropes "R", thus allowing the brake linings 23 and 24 to more effectively lock the ropes "R". Figs. 4a and 4b are plan views, showing the operation of the second-type device of Fig. 2b. That is, Fig. 4a shows the device while releasing the ropes. Fig. 4b shows the device while locking the ropes by the first and second movable plates 21 and 22. The general shape of the second-type device remains the same as that of the first-type device.

However, in the second-type device, each of the bolt members 10 movably passes through a fixed sleeve bushing 11 of the fixed plate 20. The first movable plate 21 is set in the device so as to be movable relative to the fixed plate 20. The compression coil springs 12 are fitted over the bolt members 12 at a position between the two movable plates 21 and 22. The support plate 13 is set in the device at a position outside the fixed plate 20 in a way such that the plate 13 is positioned in parallel to the fixed plate 20. The above support plate 13 has an opening at which the cylinder actuator 15, having the plunger 16, is mounted to the support plate 13. The second-type device has a plurality of limit switches 14 on the support plate 13.

Four sleeve bushings 11 are fixedly mounted to the four corners of the fixed plate 20 and individually allow a bolt member 10 to movably pass through. On the other hand, one opening is formed at the center of the fixed plate 20, with the plunger 16 of the cylinder actuator 15 movably passing through the opening of the fixed plate 20 prior to coming into contact with the first movable plate 21 at the end.

The actuation plunger 16 is set in the cylinder actuator 15 in a way such that it is hydraulically movable in opposite directions relative to the fixed cylinder casing of the actuator 15. A stopper 16a is provided on the plunger 16 for limiting a movement of the plunger 16 relative to the fixed plate 20. A flange is formed at the end of the cylinder casing of the actuator 15. The cylinder casing of the actuator 15 is held by the support plate 13 at said flange. In the rope locking unit 2 of the second-type device, the first and second movable plates 21 and 22 are arranged in parallel to each other while being normally biased in opposite directions by the compression coil springs 12. The two plates 21 and 22 are thus normally spaced out while forming a gap between them. The two plates 21 and 22 individually have a flat brake lining 23, 24 on the locking surface in the same manner as that described for the first-type device. A plurality of rope locking grooves 23a, 24a are longitudinally and parallely formed on the locking surface of the two linings 23 and 24.

Fig. 6 is a circuit diagram of a hydraulic circuit used for actuating a movable plate of the device according to this invention. The hydraulic circuit for the device of this invention has an oil pressure generating unit 3. The above unit 3 comprises a hydraulic pump 31, a pressurized oil accumulator 33, and a directional control solenoid valve 34. The pump 31 compresses the actuating oil from an oil tank 32, thus pressurizing the oil. The accumulator 33 accumulates the pressurized oil while maintaining the pressure of the oil. The solenoid valve 34 controls flow of the pressurized oil for the cylinder actuator 15. The above unit 3 also comprises a check valve 35, a relief valve 36, a pressure switch 37 and a pressure meter 38 in a conventional manner. The above unit 3 is connected to the cylinder casing of the cylinder actuator 3 through an oil pipe 39.

In the device of this invention, the bolt members 10 individually have one compression coil spring 12 and hold both the support plate 13 and the movable plate 22 relative to the fixed plate 20. Of course, it should be understood that the number of bolt members 10 may be changed as desired.

The operational effect of the above emergency rope brake device of this invention will be described hereinbelow.

The first-type device is operated as follows. When the elevator car "a" is stopped at a desired floor of a building with the rope brake device releasing the ropes "R" as shown in Fig. 3a, the cylinder actuator 15 is operated by the pressurized oil from the oil pressure generating unit 3, and so the plunger 16 of the actuator 15 pushes the fixed plate 20 as shown in Fig. 3b.

However, since the fixed plate 20 is secured to the frame "F" at both ends thereof, the hydraulic force, applied to the plate 20 from the plunger 16, acts as a reaction force for the cylinder casing of the actuator 15. Therefore, the support plate 13, which holds the cylinder casing, is biased by the reaction force, thus being moved away from the fixed plate 20. Such a movement of the support plate 13 pulls the bolt members 10, thus moving the movable plate 22 in a direction toward the fixed plate 20 while overcoming the biasing force of the compression coil springs 12. In such a case, the ropes "R" are locked by the brake linings 23 and 24 of the two plates 20 and 22. That is, the ropes "R" are firmly caught by the locking grooves 23a and 24a of the two brake linings 23 and 24, thus being stopped. When a start button is operated by a user so as to move the elevator car "a" from the stop mode, the ropes "R" have to be primarily released from the locked position. In order to release the ropes "R" from the locked position, the pressurized oil returns from the actuator 15 to the tank in response to a signal from the control unit of the elevator car, thus allowing the plunger 16 to be retracted into the cylinder casing of the actuator 15. Therefore, the movable plate 22 returns to its original position by the restoring force of the compression coil springs 12 while releasing the ropes "R" from the brake linings 23 and 24, thereby accomplishing the rope releasing position of the locking unit 2 as shown in Fig. 3a. Such a rope releasing position is maintained until the pressurized oil from the unit 3 is applied to the cylinder actuator 15 of the reaction unit 1. During such a rope releasing position, the device of this invention allows the elevator car "a" to be movable up or down within the shaft.

On the other hand, the second-type device is operated as follows. When the elevator car "a" is stopped at a desired floor of the building with the rope brake device releasing the ropes "R" as shown in Fig. 4a, the cylinder actuator 15 is operated by the pressurized oil from the oil pressure generating unit 3, and so the plunger 16 of the actuator 15 pushes the first movable plate 21 as shown in Fig. 4b. In such a case, the moving distance of the plunger 16 is limited in a way such that the movement of the plunger 16 is stopped when the stopper 16a comes into contact with the fixed plate 20. Therefore, the first movable plate 21 moves toward the ropes "R" from the time the plunger 16 starts to move to the time the stopper 16a comes into contact with the fixed plate 20.

However, the pressurized oil is continuously applied to the cylinder casing of the actuator 15 after the plunger 16 is stopped by the stopper 16a. In such a case, the hydraulic force is applied to the fixed plate 20 from the plunger 16 and acts as a reaction force for the cylinder casing of the actuator 15 in the same manner as that described for the first-type device. The support plate 13 is thus biased by the reaction force and is moved away from the fixed plate 20. The bolt members 10 are pulled by the support plate 13, and so the second movable plate 22 is moved in a direction toward the first movable plate 21 while overcoming the biasing force of the compression coil springs 12. The ropes "R" are firmly caught and stopped by the locking grooves 23a and 24a of the two brake linings 23 and 24 provided on the two movable plates 21 and 22.

When a start button is operated by a user so as to move the elevator car "a" from the stop mode, the pressurized oil returns from the actuator 15 to the tank in response to a signal from the control unit of the elevator car. The plunger 16 of the actuator 15 is released from the hydraulic pressure. In such a case, the second movable plate 22 primarily returns to its original position by the restoring force of the compression coil springs 12. Thereafter, the support plate 13 returns to its original position along with the first movable plate 21. The stopper 16a of the plunger 16 is moved away from the fixed plate 20, while the ropes "R" are released from the brake linings 23 and 24 of the two movable plates 21 and 22. The rope releasing position of the locking unit 2 is accomplished as shown in Fig. 4a. Such a rope releasing position is maintained until the pressurized oil from the unit 3 is applied to the cylinder actuator 15 of the reaction unit 1. During such a rope releasing position, the second-type device of this invention allows the elevator car "a" to be movable up or down within the shaft. During an operation of the elevator system, an abnormal operation may occur in the system due to a reduction in the braking force of the main brake unit, a reduction in the frictional force between the suspension ropes and the rope pulleys, or a difference in weight between the elevator car and a balance weight. In such a case, the elevator car may fail to be firmly stopped at a designated floor, but slip down at a time a user goes into or out of the car. The elevator car, with such abnormal conditions of the parts, may be also rapidly moved up or down in the shaft at an exceedingly high speed. This may cause safety hazards. However, such safety hazards are almost completely prevented by the emergency rope brake device of this invention as follows. In an occurrence of such an abnormal operation of the elevator system, the control unit of the elevator car "a" outputs a signal to the oil pressure generating unit 3 of the hydraulic circuit, thus starting the operation of the reaction unit 1 and the rope locking unit 2 of the device. That is, in response to the signal from the control unit, the unit 3 applies the pressurized oil to the cylinder actuator 15 and extends the plunger 16 as described above. In the case of the second-type device, the plunger 16 primarily pushes the first movable plate 21 until the stopper 16a comes into contact with the fixed plate 20. Therefore, the hydraulic force of the actuator 15 is applied to the fixed plate 20 from the plunger 16 and acts as a reaction force for the cylinder casing of the actuator 15. The support plate 13 is thus biased by the reaction force and is moved away from the fixed plate 20 while pulling the bolt members 10. In such a case, the second movable plate 22 is moved in a direction toward the first movable plate 21. Therefore, the ropes "R" are firmly caught and stopped by the locking grooves 23a and 24a of the two brake linings 23 and 24 provided on the two movable plates 21 and 22. The elevator car "a" is thus stably stopped.

In the second-type device of this invention, the locking grooves 23a, longitudinally formed on the brake lining 23 for the second movable plate 22, have a trapezoidal cross-section. The brake lining 24 for the first movable plate 21 of the second-type device has a plurality of longitudinal locking ribs with a concave locking groove 24a being formed along the top surface of each locking rib. Such a specifically designed configuration of the locking grooves 23a and 24a provides a wedging effect for the ropes "R", thus allowing the brake linings 23 and 24 to more effectively lock the ropes "R".

The oil pressure generating unit 3 of the Fig. 6 is operated as follows. In the unit 3, the hydraulic pump 31 is operated to pressurize the actuating oil. The pressurized oil from the pump 31 passes through the check valve 35 prior to being introduced into the oil accumulator 33, thus being accumulated in said accumulator 33. In an occurrence of such an abnormal operation of the elevator system, the control unit of the elevator car outputs a signal to the unit 3. In response to the signal from the control unit, the solenoid valve 34 is opened, thus allowing the pressurized oil from the accumulator 33 to pass through so as to be applied to the cylinder casing of the actuator 15. The plunger 16 of the actuator 15 extends from the cylinder casing, and so both the reaction unit 1 and the rope locking unit 2 of the device are hydraulically operated in the same manner as described above and firmly lock the ropes "R" using the brake linings 23 and 24 of the two movable plates 21 and 22. On the other hand, since the pressurized oil is output from the accumulator 33, the pressure of said accumulator 33 is reduced. In such a case, the pressure switch 37 operates the pump 31 to pressurize new actuating oil from the oil tank 31 prior to filling the accumulator 33 with the pressurized oil until the pressure of the accumulator 33 reaches a reference level.

When a normal operation start signal is output from the control unit to the oil pressure generating unit 3, the solenoid valve 34 is turned on. The oil return passage of the solenoid valve 34 is thus opened and allows the pressurized oil to return from the cylinder actuator 15 to the oil tank through a return line. Of course, when the pressurized oil is discharged from the cylinder casing of the actuator 15 in response to the normal operation start signal from the control unit, the plunger 16 is retracted into the cylinder casing while allowing the rope locking unit 2 of the device to accomplish the rope releasing position. Therefore, the elevator car "a" is movable up and down within the shaft.

Industrial Applicability

As described above, the present invention provides an emergency rope brake device for elevator systems. The device is designed to be selectively operated in an occurrence of an abnormal operation of the elevator system wherein the elevator car undesirably slips down during a temporary stop mode or is rapidly moved up or down in the shaft at an exceedingly high speed during a moving mode due to a breakage or a malfunction of a main brake unit. The device thus firmly locks and stops the suspension ropes of the elevator system using a hydraulic pressure while almost completely preventing safety hazards of the elevator system. The device thus finally accomplishes a desired operational safety of elevator systems.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

Claims :

1. An emergency rope brake device for elevator systems, said device being used for braking the ropes of an elevator system in an occurrence of an abnormal operation of said system, with the ropes being wrapped around rope pulleys within an elevator shaft and being individually connected to an elevator car and a balance weight at both ends thereof, comprising: an oil pressure generating unit operated in response to a control signal output from a control unit of said elevator system, thus pressurizing actuating oil prior to supplying the oil under pressure to the device, said oil pressure generating unit comprising a directional control solenoid valve and a pressurized oil accumulator; a reaction unit operated by the oil under pressure from the oil pressure generating unit, said reaction unit consisting of: a cylinder actuator connected to said solenoid valve of the oil pressure generating unit through an oil pipe, thus being selectively operated by the oil under pressure output from the accumulator under the control of said solenoid valve, said actuator having a plunger within a cylinder casing fixed to a support plate; and a plurality of bolt members individually fixed to said support plate at one end thereof, with a compression coil spring being fitted over each of the bolt members; a rope locking unit used for selectively locking the ropes in conjunction with said reaction unit, said locking unit consisting of: a fixed plate securely mounted to a frame at both ends thereof and positioned in parallel to said support plate, and allowing the bolt members to movably and perpendicularly pass through, said fixed plate being used for generating a reaction force in response to a pressure applied thereto from the plunger during an operation of said actuator, thus allowing the support plate to be movable along with the cylinder casing of the actuator in a direction away from the fixed plate; and a main movable plate fixed to said bolt members at a position opposite to the support plate, with the fixed plate being positioned between the movable plate and the support plate, said main movable plate being normally biased in a direction away from the fixed plate by said compression coil springs so as to accomplish a rope releasing position and being selectively movable in a direction toward the fixed plate so as to accomplish a rope locking position when the support plate is moved away from the fixed plate due to the reaction force applied from the fixed plate to the support plate.

2. The emergency rope brake device according to claim 1, wherein said rope locking unit further comprises an additional movable plate, said additional movable plate being movably held by said bolt members at a position between the main movable plate and the support plate while being in parallel to both the main movable plate and the fixed plate, with the compression coil springs being stopped by the two movable plates and the plunger passing through the fixed plate prior to being brought into contact with the additional movable plate, said additional movable plate being thus normally biased in a direction away from the main movable plate by the compression coil springs so as to accomplish the rope releasing position, and being selectively movable in a direction toward the main movable plate by the plunger of the actuator so as to accomplish the rope locking position.

3. The emergency rope brake device according to claim 1 or 2, wherein a brake lining is provided on each locking surface of said fixed plate and said two movable plates, with a plurality of rope locking grooves being longitudinally formed on said brake lining.