JP2000219450A - Elevator equipment - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a method for controlling a vehicle when a car descends at an abnormal speed.
Provided is an elevator apparatus including a transmission device for urgently stopping a car and having improved reliability and safety. A governor (6) has a governor rope (5) connected to a car (1) on which a person rests, detects a vertical speed of the car, and raises the governor rope when an abnormal lowering speed of the car is detected. A pair of emergency stop devices 10 and 10 provided on both left and right sides of the car for urgently stopping the car in a state where the governor rope of the speed machine is raised, and a pulling force of the governor rope is transmitted to the pair of left and right emergency stop devices,
And a transmission device 9 for simultaneously operating these safety devices. When the pulling-up force of the governor rope is less than a predetermined value, the transmission device 9 is actuated in a direction to hinder the operation of the transmission device and when the pulling force exceeds a predetermined value. A tension spring 13 for applying an elastic force in each direction was used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator system which is activated when a car descends at an abnormal speed for some reason to stop the car in an emergency. And improvement of a transmission device that operates stably.

[0002]

2. Description of the Related Art An elevator apparatus has a governor rope connected to a car on which a person is mounted, and a governor that raises the governor rope when an abnormal lowering speed is detected by detecting an elevating speed of the car; It is composed of a pair of emergency stop devices provided on both left and right sides of the car for urgently stopping the car in the raised state, and a transmission device that transmits the lifting force of the governor rope to both the emergency stop devices and operates in synchronization.

FIG. 8 shows a transmission device constituting a conventional elevator device. The lifting force applied to the governor rope a is transmitted to the shaft c via the lever b, and causes the shaft c to rotate clockwise. The lever d rotates together with the shaft c to lift the lift rod e.

At the same time, the lever f rotates together with the shaft c to swing the connecting rod j to the left in the drawing. Accordingly, the shaft i rotates counterclockwise via the lever h, the lever g provided on the shaft i rotates, and the lift rod k is pulled up.

An emergency stop device (not shown) is connected to the lower end of each of the lift rods e and k.
As k increases, each safety gear operates simultaneously,
The braking force is applied to the car to make an emergency stop.

[0006]

At this time, it is necessary to reliably apply braking to the left and right safety gears at the same timing. For this purpose, the transmission device must transmit the rotational force transmitted from the governor rope a to the lever b in synchronization with the lift rod k via the lift rod e and the connecting rod j.

[0007] These series of operations are performed in a state in which a predetermined force (for example, 40 kgf or more) is applied from the governor.
It must be performed for the first time, and certainty of operation is required.

In order to ensure the operation of the transmission device,
A catcher M is provided at the other end of the lever d. As shown in FIGS. 9A and 9B in an enlarged manner, the lever d
And a pair of plugs q and r provided to face each other in the radial direction of the catcher shaft p.

At the end of the catcher shaft p, a pair of V-shaped grooves s, s are provided so as to face each other in the radial direction.
The tips of the plugs q and r having the same shape are engaged. One plug q is attached and fixed to the support base t, while the other plug r is supported by the support base t via a compression spring u.

That is, the position of the catcher shaft p is held by the pair of plugs q and r, and a force overcoming the elastic force of the compression spring u is applied to the catcher shaft p. Operate the safety gear.

As described above, in the conventional elevator apparatus, the force for lifting the lift rods e and k depends on the governor rope a even after the catcher M starts to move by applying a force equal to or more than a predetermined force to the governor rope a.

For this reason, if any abnormal load occurs in the transmission device, even if the catcher shaft p moves once and the V-shaped grooves s, s come out of the tips of the plugs q, r, the catcher shaft p is still in place. It is feared that there will be no quantitative displacement.

That is, since one of the plugs r always urges the catcher shaft p elastically by the compression spring u, even if the V-shaped grooves s, s are formed by the plugs q, r
Even if it comes out of the tip, immediately after that, the catcher shaft p
There is a risk of preventing the movement of the light, and it is hard to say that the reliability is perfect.

The present invention has been made in view of the above circumstances, and has as its object the purpose of the present invention being that it does not easily malfunction during normal use, and that when the car descends at an abnormal speed, the left and right sides of the car will not move. It is an object of the present invention to provide an elevator device having a transmission device for urgently stopping a car by instantly and surely operating an emergency stop device, thereby improving reliability and safety.

[0015]

In order to satisfy the above-mentioned object, an elevator apparatus according to the present invention has a governor rope connected to a car on which a person is to be mounted, and detects an elevator speed of the car. A governor that pulls up the governor rope in a state where the abnormal lowering speed of the car is detected,
A pair of emergency stop devices provided on the left and right sides of the car for urgently stopping the car in a state where the governor rope of the speed governor is raised, and transmitting the lifting force of the governor rope to the emergency stop device, A transmission device for activating the device,
When the pulling-up force of the governor rope is less than a predetermined value, an elastic force is applied in a direction to hinder the operation of the transmission device, and in a direction to operate the transmission device when the pulling-up force of the governor rope is equal to or more than a predetermined value. It is characterized by doing.

According to a second aspect of the present invention, in the elevator apparatus according to the first aspect, a toggle spring is used as a means for applying the elastic force.

According to a third aspect of the present invention, in the elevator apparatus according to the first aspect, a tension spring is used as a means for applying the elastic force.

According to a fourth aspect of the present invention, in the elevator apparatus according to the first aspect, a compression spring acting as a toggle spring is used as the means for applying the elastic force.

According to a fifth aspect of the present invention, in the elevator apparatus according to the first aspect, a curved leaf spring acting as a toggle spring is used as the means for applying the elastic force.

By adopting the means for solving the above problems, when the car descends at an abnormal speed, the transmission device operates the left and right emergency stop devices instantaneously and surely, so that the car can be reliably moved. Make an emergency stop.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a basket on which a person rests, and is hung on one end of a main rope 2 hanging from a hoist (not shown) arranged at the top of the building. A counter weight (not shown) is attached to the other end of the main rope 2, and a weight that can be balanced with the total weight of the car and the loaded load is selected.

Guide shoes 3 are provided on the upper and lower portions of the car 1 and on both left and right sides, and guide rails 4 and 4 provided from the lowermost portion to the uppermost portion of the building are interposed and engaged with each other. I have. Depending on the type of the car 1, a guide roller may be used instead of the guide shoe 3.

By driving the hoist to rotate, the main rope 2 is raised and lowered, and the car 1 on which a person is placed is raised and lowered in a state of being balanced with the counterweight. Since the guide shoes 3 are always engaged with the guide rails 4, the car 1 maintains a stable posture without causing sideways movement.

A governor rope 5 is stretched in parallel with the main rope 2. The governor rope 5 is wrapped around a governor (governor) 6 disposed in the vicinity of the hoist and pulleys 6a and 7a attached to a governor tension 7 disposed on the foundation floor so that the governor rope 5 can run endlessly. It is.

The socket 8 provided at an intermediate portion of the governor rope 5 is connected to the car 1 via a transmission device 9 described later.
Linked to That is, the governor rope 5 travels integrally with the vertical movement of the car 1, and the governor 6 detects the vertical speed of the car 1 at this traveling speed.

At the lower ends of the left and right sides of the car 1, emergency stop devices 10, 10 are provided, and the transmission device 9 applies a holding force of the governor rope 5 to a pair of left and right emergency stop devices 10, 10.
10 and these are operated synchronously.

The transmission device 9 is mounted on the upper surface of the car 1, and a pair of right and left transmission mechanisms 11A, 1A for transmitting the holding force of the governor rope 5 directly to the emergency stop devices 10, 10.
1B, a coupling body 12 for synchronizing the movements of the transmission mechanisms 11A and 11B, and a transmission mechanism 11 for the first time when the holding force of the governor rope 5 becomes a certain value or more.
A and 11B and a force control mechanism 13 for operating the connecting body 12.

Next, the details of the transmission device 9 will be described with reference to FIG.

The transmission mechanism 11A on the left side of FIG.
A shaft 15A supported over one side of the upper frame 4a and the upper frame 14b, one end of which is fixedly fitted to the shaft 15A, and the other end of which is turned via a pin 16 to a socket 8 at an intermediate portion of the governor rope 5. Lever 17B movably connected
And a lever 17 having one end fitted and fixed to the shaft 15A and the other end connected and fixed to the upper end of the lift rod 18A.
C.

The lower end of the lift rod 18A is the car 1
And is connected to one of the safety devices 10 disposed at the lower end of the car 1. When the lift rod 18A is pulled up by a predetermined amount,
For the first time, one safety device 10 is operated.

The transmission mechanism 11B on the right side of the figure has an upper frame 1 so as to be parallel to the shaft 15A at a predetermined interval.
4a and a shaft 15B supported over the other side of the upper frame 14b, and a lever 17F having one end fitted and fixed to the shaft 15B and the other end connected and fixed to the upper end of the lift rod 18B. Be composed.

The lower end of the lift rod 18B is a car 1
And is connected to the other safety device 10 disposed at the lower end of the car 1. When the lift rod 18B is pulled up by a predetermined amount,
For the first time, the other safety device 10 is operated.

The connecting member 12 connects the transmission mechanism 11A and the transmission mechanism 11B, and includes a lever 17D and a lever 17E, one ends of which are fixedly fitted to the shafts 15A and 15B, respectively.
A connecting rod 19 is provided between the other end portions of D and 17E via a pin, and connects the levers 17D and 17E.

In the connecting rod 19, the rods connected to the levers 17D and 17E are separate bodies, and the rod ends are connected to each other via a turnbuckle 20. By turning the screw portion of the turn buckle 20, the effective length of the connecting rod 19 can be adjusted, and as a result, the left and right transmission mechanisms 11A, 11B are described later.
The adjustment for synchronizing the operation timings is possible.

The force control mechanism 13 includes the lever 17B
One end is hooked to a pin 21 provided at an intermediate portion of the upper frame 14a, and the other end is formed of an elastic body attached and fixed to the upper frame 14a by an appropriate means. In this case, a tension spring is used as the elastic body. Hereinafter, the force control mechanism is referred to as a tension spring 13.

Although the details of the emergency stop device 10 are not shown, they are arranged on both side surfaces of the guide rail 4 and provided at the lower ends of the lift rods 18A and 18B, respectively, so that the emergency stop device 10 always moves up and down integrally with the car 1. Driven wedges,
And a plurality of rollers provided diagonally in a row outside the wedges. The plurality of rollers are supported by a lower frame of the car 1, and are themselves rotatably supported by a support shaft. The support shaft is fixed to the lower frame.

Therefore, the lift rods 18A, 18B
When the wedge is raised with the rise of the roller, the wedge is inserted between the guide rail and the roller row and receives a frictional force. At last, the wedge tightens the guide rails from both sides to apply a braking force to the car 1.

If the car 1 descends at a speed much higher than the set speed for some reason, the governor rope 5
And the governor rope 5 is pulled up to apply a holding force for drop prevention.

The force applied to governor rope 5 from governor 6 is transmitted to shaft 15A via lever 17B,
This is rotated clockwise. The lever 17C rotates together with the shaft 15A, and the lift rod 18A is pulled up.

At the same time, the lever 1 together with the shaft 15A
7D rotates, and swings the connecting rod 19 in a predetermined direction. From this, the shaft 15B rotates through the lever 17E.
Of the lift rod 18
B is raised.

Each of the lift rods 18A and 18B raises the wedge constituting the safety device 10 and inserts it between the roller and the guide rail 4, so that the car 1 is subjected to emergency braking and stopped safely.

At this time, the left and right safety devices 10,
10 needs to apply braking to the left and right guide rails 4 and 4 at the same timing. For this purpose, the rotational force transmitted from the governor rope 5 to the lever 17B must be transmitted in synchronization with the lift rod 18A and the lift rod 18B via the connecting body 12.

Next, a tension spring 13 which is a force control mechanism for operating the transmission mechanisms 11A and 11B synchronously.
3 will be described in detail with reference to FIG. 3 and a graph showing changes in load and flexural deformation on the tension spring 13 in FIG.

The center line CLa, which is a line connecting the fixed end B and the fixed end A of the tension spring 13, and the center line C of the lever 17B
A predetermined angle θ is formed between Lb. The extension spring 13 is extended from its free length to form a deflection δ1, and is stretched between the fixed end A and the fixed end B in a state of the full length L1.

Assuming that the tensile force, which is the elastic repulsive force of the tension spring 13 at this time, is Po, the central axis C of the lever 17B
The component force Pt along Lb and the component force Pr in the tangential direction of the fixed end A
Occurs.

The lever 17B rotates about the shaft 15A as a fulcrum. When the lever 17B rotates by an angle α from the initial state, the center axis CLb and the center axis C of the tension spring 13 are moved.
La matches. Then, here, the tension spring 13 further expands by δ2, and is deformed by bending.

In the lever 17B, the shaft 15
Assuming that the distance from the pivotal support position of A to the hooking position, which is the fixed end A of the tension spring 13, is Lp, and the distance from the other end to the point Q, which is the hooking position of the governor rope 5, is Lf. Assuming that the tension (pulling force) from the force is Fo, the component forces Fr and Ft are formed. Here, F
The angle α formed by Fr with respect to o becomes the same as α described above.

Then, the lever 17 is moved by the tension spring 13.
The moment Ml for rotating B in the counterclockwise direction about the shaft 15A is as follows: Ml = Pr × Lp = Po × sin θ × Lp (1) On the other hand, the lever 1 is pulled by the tension Fo from the governor rope 5.
7B is a moment M for rotating clockwise.
r = Mr = Fr × Lf = Fo × cosα × Lf (2) That is, in the state of Ml <Mr (3), the lever 17B starts rotating clockwise around the shaft 15A. Will do.

Also, the lever 17B is extended by the tension spring 13.
Is minimized at the point of θ = 0 where the center axis CLa of the tension spring 13 and the center axis CLb of the lever 17B coincide, and Ml = Ps × sin θ × Lp = 0. ... (4)

Beyond the point θ = 0, the force of the tension spring 13 reverses to the force that attempts to rotate the lever 17B clockwise. Therefore, the load for operating both transmission mechanisms 11A and 11B in synchronization needs to be set to the maximum value of Ml.

Next, the lever 17 by the tension spring 13 is used.
A specific action on B will be described. FIG. 5 (A)
As shown in the figure, normally, the tension spring 13 is extended and the fixed end A
As a result, the elastic repulsive force of the tension spring 13 acts from the position where the lever 17B is hung on the pin 21 at the intermediate portion of the lever 17B, and acts to rotate the lever 17B counterclockwise around the shaft 15A as a fulcrum.

The tension spring 13 is subjected to an initial compressive force that does not shrink and deform until a predetermined force or more is applied. The longitudinal spring generated when the car 1 moves up and down, the tension caused by the acceleration, or the car 1 is intentionally shaken. The degree of swing of the car 1 caused by the above is set so as not to have any influence.

When the car 1 abnormally descends for some reason, the governor 6 detects this and applies a force to the governor rope 5 that is higher than a certain value (the initial tension of the tension spring 13). The lever 17B integrated with the governor lobe 5 rotates clockwise around the shaft 15A.

Accordingly, the pin 21 provided on the lever 17B moves in the same direction, and the tension spring 13 having one end hooked thereto is extended. Therefore, an elastic repulsive force acts on the tension spring 13 to pull the lever 17B back in the counterclockwise direction.

When the pulling up force of the governor rope 5 is weak, for example, when the passenger in the car 1 jumps on purpose or when the car 1 moves in and out between the normal elevating speed and the abnormal elevating speed, the pulling is performed. The elastic repulsive force of the spring 13 overcomes and returns the lever 17B to the original state.

As shown in FIG. 5 (B), if the car 1 is abnormally moved up and down significantly above a predetermined speed, the tension spring 13 is extended without any room for applying an elastic repulsive force, and finally the lever 13 is extended. The center line CLb of 17B and the center line CLa of the tension spring 13 reach a position where they coincide. Here, the force of the tension spring 13 for returning the lever 17B to the original position becomes zero.

As shown in FIG. 5C, the pivotal position of the lever 17B is set at the center line CLb of the lever 17B and the tension spring 1B.
Immediately after passing through the position where the center line CLa of the third spring 3 coincides, the tension spring 13 acts as a so-called toggle spring, and the elastic repulsive force acts as a force for rotating the lever 17B clockwise.

That is, the lever 17B surely pivots in a very short time and almost instantly to pivot the shafts 15A and 15B.
10 synchronously stops the car 1 in an emergency.

As described above, it is possible to realize the transmission device 9 having the more reliable force transmission mechanism 13 while having a simple structure with a small number of parts.

FIG. 6 shows a force transmission mechanism 1 according to the second embodiment.
9 shows a transmission device 9B with 3A. Here, a lever 17Ba for connecting the governor rope 5 and the shaft 15A is provided.
Is terminated at the end on the shaft 15A side.
Instead, a lever 17Ca fitted to the shaft 15A is used.
Is extended from the shaft 15A to the side opposite to the lift rod 18A, and a compression spring 1 constituting a force control mechanism is provided at this end.
One end of 3A is hooked.

Except for this, each transmission mechanism 11A, 11B
Since the configuration of the connector 12 is the same as the configuration of the first embodiment described above, the same reference numerals are given and new description is omitted.

The compression spring 13A is formed in a coil shape. One end of the compression spring 13A is fixed to the lever 17Ca as a fixed end C, and the other end is fixed to the upper frame 14b as a fixed end D by appropriate means. . Therefore, the compression spring 13A is connected to the lever 17C around the shaft 15A.
a is elastically pressed and urged to rotate in the counterclockwise direction.

When the car 1 descends beyond a predetermined speed for some reason, the governor rope 5 is pulled up with a constant holding force, and the lever 17Ba attempts to rotate clockwise around the shaft 15A.

The turning moment of the lever 17Ba is transmitted to the lever 17Ca via the shaft 15A, and
Acts to compress the compression spring 13A attached between -D.

The compression spring 13A is applied with an initial compression force which does not contract and deform until a predetermined force or more is applied.
The car 1 caused by pitching caused when the car 1 moves up and down, tension caused by acceleration, or intentionally shaking the car
Is set so that there is no influence on the degree of shaking.

When the lifting force on the governor rope 5 becomes equal to or greater than a predetermined value, the compression spring 13A is first compressed and the lever 17Ca rotates clockwise about the shaft 15A.

The central axis of the lever 17Ca and the compression spring 13A
Until the angle θ formed by the center axis of the compression spring 1 becomes zero.
The force for pushing the lever 17Ca back to the original position is exerted by the elastic repulsive force of 3A. However, when the angle θ is 0
, The compression spring 13A exerts an elastic force in a direction to further rotate the lever 17Ca.

Therefore, the compression spring 13A acts as a toggle spring, and the lever 17Ca rotates reliably and almost instantaneously with the lever 17Ba in a very short time. This rotational power is transmitted to the other transmission mechanism 11B via the connecting body 12, and the emergency stop devices 10, 10 on both sides are reliably operated in synchronization, and the car 1 is stopped in an emergency.

As described above, it is possible to realize the transmission device 9A including the force control mechanism 13A with higher reliability while having a simple structure with a small number of parts.

FIG. 7 shows a force control mechanism 1 according to the third embodiment.
3B shows a transmission device 9B with 3B. A bent leaf spring 13 that constitutes a force control mechanism at the end of the lever 17Ca described above.
One end of B is hooked.

Except for this, each transmission mechanism 11A, 11B
Since the configuration of the connector 12 is the same as the configuration of the first embodiment described above, the same reference numerals are given and new description is omitted.

The curved leaf spring 13B has a semicircular curve between both ends, and one end of the curved leaf spring 13B has a lever 17C.
a is rotatably connected to a through a pin as a fixed end E,
The other end is connected to the upper frame 14b via a pin as a fixed end F by an appropriate means. Therefore, the curved leaf spring 1
Reference numeral 3B elastically presses and biases the lever 17Ca to rotate counterclockwise around the shaft 15A.

When the car 1 descends beyond a predetermined speed for some reason, the governor rope 5 is pulled up with a constant holding force, and the lever 17Ba attempts to rotate clockwise around the shaft 15A.

The turning moment of the lever 17Ba is transmitted to the lever 17Ca via the shaft 15A, and
Acts to compress the curved leaf spring 13B attached between −F.

An initial compressive force which does not contract and deform until a predetermined force or more is applied is applied to the curved leaf spring 13B, and the vertical spring generated when the car 1 moves up and down, the tension due to acceleration, or the intentional swinging of the car. Is set so that there is no influence on the degree of car shake caused by the car.

When the lifting force on the governor rope 5 becomes equal to or more than a predetermined value, the curved leaf spring 13B is compressed and the lever 17Ca rotates clockwise about the shaft 15A.

The central axis of the lever 17Ca and the compression spring 13A
Until the angle .theta. Formed by the center axis becomes zero, a force for pushing the lever 17Ca back to the original position is exerted by the elastic repulsive force of the curved leaf spring 13B. However, if the angle θ exceeds 0, the bent leaf spring 13B exerts an elastic force in a direction to further rotate the lever 17Ca.

Therefore, the curved leaf spring 13B performs a toggle spring action, and the lever 17Ca rotates reliably and almost instantaneously with the lever 17Ba for a very short time. This rotational power is transmitted to the other transmission mechanism 11B via the connecting body 12, and the emergency stop devices 10, 10 on both sides are reliably operated in synchronization, and the car 1 is stopped in an emergency.

As described above, it is possible to realize a transmission device 9B having a more reliable force control mechanism 13B with a simple structure having a small number of parts.

The above-described force transmission mechanisms 13, 13
A and 13B are all constituted by springs, but are not limited to this in practice. In short, the transmission mechanisms 11A and 11B are activated when the pulling-up force of the governor rope 5 exceeds a predetermined value. It is preferable that the control of the operating force is performed by a single elastic body.

[0081]

As described above, according to the present invention, a simple structure using a single elastic body is used. When the car descends at an abnormal speed, the emergency stop devices on both the left and right sides are synchronized. Instantaneously and surely to bring the car to an emergency stop,
This has the effect of improving reliability and safety.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an elevator apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a transmission device including a force control mechanism according to the first embodiment of the present invention, with a part of the transmission device omitted;

FIG. 3 is a diagram illustrating a force applied to a lever B according to the embodiment.

FIG. 4 is a characteristic diagram of flexural deformation with respect to a load of a tension spring according to the embodiment.

FIG. 5 is a view for explaining the action of a tension spring on a lever B according to the embodiment.

FIG. 6 is a configuration diagram of a transmission device including a force control mechanism according to a second embodiment of the present invention, with a part thereof omitted;

FIG. 7 is a configuration diagram of a transmission device including a force control mechanism according to a third embodiment of the present invention, with a part thereof omitted.

FIG. 8 is a configuration diagram in which a conventional transmission device including a force control mechanism is partially omitted.

FIG. 9 is a configuration diagram of the conventional force control mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Basket, 5 ... Governor rope, 6 ... Governor, 10 ... Emergency stop device, 9, 9A, 9B ... Transmission device, 11A, 11B ... Transmission mechanism, 12 ... Connection body, 13 ... Force control mechanism (Tension spring) 13A: compression spring; 13B: curved leaf spring.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Kinoshita 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu Factory (72) Inventor Kazuhiro Tanaka 6-27 Kita Shinagawa, Shinagawa-ku, Tokyo Toshiba Elevator Co., Ltd. Company F-term (reference) 3F304 CA13 DA33

Claims (5)

[Claims] 1. A governor having a governor rope connected to a car on which a person is to be mounted, which detects a vertical speed of the car, and raises the governor rope when an abnormal lowering speed of the car is detected. A pair of emergency stop devices provided on both the left and right sides of the car for urgently stopping the car in a state where the governor rope of the machine is raised, transmitting the lifting force of the governor rope to the emergency stop device, and operating these emergency stop devices An elevator apparatus comprising: a transmission device that causes the governor rope to pull up when the pulling force of the governor rope is less than a predetermined value; An elevator apparatus, wherein an elastic force is applied in a direction in which the actuator operates. 2. The elevator apparatus according to claim 1, wherein a toggle spring is used as the means for applying the elastic force. 3. The elevator apparatus according to claim 1, wherein a tension spring is used as the means for applying the elastic force. 4. The elevator apparatus according to claim 1, wherein a compression spring acting as a toggle spring is used as the means for applying the elastic force. 5. An elevator apparatus according to claim 1, wherein said means for applying said elastic force uses a curved leaf spring which acts as a toggle spring.