A NONLINEAR AND EFFICIENT EDDY-CURRENT OVERSPEED PROTECTION SYSTEM FOR ELEVATORS

Description

Technical Field of the Invention:

[0001] The invention is related to the use of nonlinear eddy-currents in the precise detection of overspeed and actuation of overspeed emergency brake for elevators and other vertical transport systems.

Prior Art:

[0002] Several safety devices must be installed in elevator systems for the safety of the passengers in passenger carrying elevators as dictated by law, such as limit switches, floor position sensors, overspeed sensors, door safety sensors etc. Some of these may be electromechanical, and others purely mechanical, but generally they must work independently of other systems of the elevator.

[0003] One of the important safety devices in the elevator system are the overspeed sensors which detect whether the elevator is exceeding design speeds in the up or down direction. Overspeed may be caused because of malfunctioning motor or motor controllers, severed traction cables, software fault or similar. In case the overspeed condition is detected, an independent brake mechanism must be triggered which must arrest the motion of the elevator car, typically by grabbing the guide rails. These will be called overspeed emergency detectors and actuators.

[0004] The conventional overspeed detection and actuation mechanism currently used in most elevators installed around the world is the cable-loop system which uses a traveling cable-loop stretched around pulleys at the top and bottom of the building and a mechanical nonlinear device which senses and restricts the speed of one of the pulleys, thus triggering an overspeed emergency brake attached to the elevator car. However, the cable-loop system that must span the height of the building is difficult and expensive to install and maintain as a safety device, especially for high-rise buildings. Multi-car elevator systems where several elevator cars operate in the same hoistway are unavoidable for the ultra high-rise buildings that are being planned and actively developed around the world. In multi-car elevator systems, the conventional safety mechanism which requires a separate cable-loop system for each elevator car is both technically difficult and takes up much room, making it impractical for general usage and limiting the number of cars that can be installed in the same hoistway.

[0005] In the state of art, a simplified drawing of a passenger elevator is shown in Fig. 1. Note the elevator car, traction cable, traction motor and counterweight. Guide rails are shown in the plan view (Fig.2). The conventional overspeed detection system of Fig. 2, consists of a loop of cable tensioned between two pulleys stretched from the bottom of the hoistway to the top. One of the pulleys connects to a speed governor; a mechanical device with nonlinear speed-resistance torque relationship, which presents negligible force on the cable at normal speeds, but a high force above a pre-defined speed. The cable is attached through the overspeed emergency brake trigger, to the elevator car at the rope connection plate shown in Fig. 2 and moves at the same speed with it. In the overspeed condition, the speed governor exerts a high force to the cable, constraining its motion, and therefore causes the overspeed emergency brake to trigger and grab the guide rails, arresting the movement of the car. This should be an irreversible operation, once the brake is triggered, it cannot be released to resume normal operation.

[0006] In the state of the art in another application, in ultra high-rise buildings, rope-less elevators which are self-driven by linear motors are used for two main reasons:

1. To eliminate the traction cables pulling the elevator car. In slanted or very tall buildings, traction cables do not work as desired.

2. To implement the idea of multi-car elevators where several elevators run in the same hoistway to increase passenger traffic. Each elevator car in the hoistway would require a separate traction cable and be impractical. However, the same linear motor stator can be shared by several elevator cars. In the same perspective, it is also necessary to replace the cable-loop overspeed emergency brake system with another which does not require moving components outside the elevator car.

[0007] For these reasons, there is another overspeed emergency detection system which is called an eddy current overspeed detector, not widely used. In these applications it is better suited than the cable-loop system, because the moving components of the overspeed emergency brake system is completely self contained within the elevator car. The idea of generating force from eddy currents, called eddy current brakes, are based on the magnetic principle of Faraday's law of induction and Lenz's law, has been known for a long time, and is widely used as eddy current brakes used to slow down large masses from high speed, such as trains and trucks, without contact friction. It can be simply explained thus: When a magnetic gradient moves over a conductive (metal) plate, the changing magnetic flux induces eddy currents in the plate. The eddy currents in turn induce a magnetic flux, and due to the interaction with the original magnetic flux, a force appears in the opposite direction to the motion.

[0008] On the other hand, in the eddy current overspeed detector, a force generating head made of a magnet or magnetic circuit, which will be called "overspeed detector magnet", is movably attached to the elevator car and triggers the overspeed emergency brake mechanism and moves over a conductive surface which will be called the "reaction surface", that spans the height of the building. In an overspeed condition, the forces generated on the overspeed detector magnet are used to trigger the overspeed emergency brake mechanism. There is an important distinction between the eddy current brake and the eddy current overspeed detector. In the former, the braking force itself is obtained from the magnetic forces, whereas in the latter, the magnetic force is used to detect the overspeed condition.

[0009] One embodiment of this approach is disclosed in the patent document of US 5366044, the general idea of using eddy currents to create a force that will trigger a mechanical overspeed emergency brake is disclosed. In this patent, a force that increases with the speed of the elevator is generated and the force is mechanically coupled to an overspeed emergency brake mechanism to trigger an overspeed emergency brake. The difference between the system proposed in this document is that the magnetic force increases proportionally (depending on the strength of the magnetic field and velocity), and this force always opposes the motion of the elevator. The disadvantages of this approach have been described as Problem 1 and Problem 2 below:

Problem 1: A force opposite to the direction of motion and proportional in magitude to velocity is constantly generated against the elevator movement and thus this system is inefficient in power consumption. In operating range of the device, the force is proportional; at extreme speeds the force will decrease. The eddy current overspeed protection systems previously disclosed have a problem of low power efficiency because these systems always apply a constant force proportional to the traveling velocity, opposing the movement of the elevator car.

Problem 2: The generated force is proportional to the velocity of the elevator car which makes it difficult to set an exact overspeed velocity in which the overspeed emergency brake is triggered. Small manufacturing tolerances may cause proportionally higher overspeeds to go undetected, or cause the overspeed emergency brake to be triggered at low speeds. The linear relationship of the overspeed sensing force to the velocity of the elevator car makes it difficult to set a precise overspeed emergency braking speed. Due to manufacturing tolerances, the overspeed trigger velocity may differ from one implementation to another. This can cause dangerous situations where the overspeed braking is not initiated at the desired speed. Since the kinetic energy of the elevator car is related to the square of the speed, the emergency brake dissipation capacity may be exceeded and the elevator car may not be safely stopped.

[0010] In another patent document of US 5628385 in the state of the art, the eddy current overspeed detection, similar to patent US 5366044 is proposed. However, there is an attempt to improve its reliability over the latter, by implementing a linear spring and a nonlinear magnetic clutch to adjust when the overspeed action is triggered: A force due to eddy currents is generated. However, a magnetic clutch prevents displacements caused by the force. When the speed increases above a threshold, the magnetic clutch releases and the force becomes free to produce a displacement on the connection arm to actuate a mechanical overspeed emergency brake. Although this patent improves over patent US 5366044 in that the brake trigger mechanism generates a displacement only at overspeed conditions, the speed set-point is not necessarily precise, and the opposing force proportional to speed still remains as a source of inefficiency.

Brief Description of the Invention

[0011] The aim of the invention is to propose a self-contained overspeed emergency brake sensing and trigger system for vertical transportation systems such as elevators which overcomes or reduces the problems of imprecise overspeed trigger velocity and low power efficiency. Another aim of the invention is to provide a practically useful overspeed emergency brake system which can be readily implemented with existing technologies. Because of its simple construction, the proposed overspeed emergency brake sensing and actuation system can replace the cable-loop mechanism of the contemporary elevators to reduce cost and complexity as well as linear motor driven elevators that are being actively developed.

[0012] The proposed invention is an enabling technology for the new generation multi-car elevator systems because the moving components of the system are completely contained within the elevator car itself. No mechanisms on the building are required.

[0013] In this invention, it is proposed an eddy-current overspeed emergency brake sensing and actuation system improved in two ways:

1. Power efficiency: During normal operation the power efficiency is high compared to other eddy current system and methods. During normal operation, the overspeed detector magnet only partially overlaps the reaction surface. Therefore, the generated forces that oppose the velocity (speed) of the elevator car are low.

2. Overspeed detection accuracy: The overspeed detector magnet swings towards and is mechanically guided to overlap the reaction surface more as the speed increases. This generates a nonlinear force on the brake trigger mechanism. By adjusting the kinematics of the system, the nonlinearity can be set precisely to occur at the pre-set speed value, therefore greatly enhancing the overspeed detection precision compared to previous systems.

[0014] Therefore the system is more compact, more efficient more reliable and more precise in an overspeed emergency condition when compared to existing eddy current overspeed detection and triggering systems used in elevators.

[0015] To accomplish the above purposes, the linear dependency between speed of the elevator and the magnet force must be reduced. In the applications of the prior art wherein the velocity-force relationship is linear, Problems 1 and 2 occur. However, in the invention the velocity-force relationship is non-linear where for operational velocities a low constant opposing force is generated (solving Problem 1) and just before the elevator reaches the overspeed trigger velocity the force rapidly increases (solving Problem 2). Mentioned velocity - force relationships of prior art and the invention are shown in Graphic-1.

Graphic -1: The Velocity -Force relationships of prior art and the invention

[0016] 

D: Release from retracted limiting element

E: Overspeed brake trigger velocity

F: Restrained by extended limiting element

[0017] The region in between D-F defines the transition region.

[0018] The system comprising magnet and kinematic constraint element, wherein magnet, and a kinematic constraint element are arranged such that a linear brake actuation force is generated at normal operating speeds of the elevator car, by moving the magnet along a reaction surface resulting a linear velocity-force relationship when the elevator car is in a normal operation speed condition, and the kinematic constraint element converts the linear speed-force relationship into a nonlinear speed-force relationship in an overspeed condition, thus keeping the mechanical losses low within the normal operating speeds, while generating a sharply increasing force in an overspeed condition.

Detailed Description of the Invention:

Description of the Figures

[0019] 

Figure 1: A schematic view of an elevator in the prior art.

Figure 2: A schematic view of cable-loop overspeed governor for elevator in the prior art.

Figure 3: A schematic view of the overspeed emergency brake system during operational velocity in one embodiment of the invention.

Figure 4: A schematic view of the overspeed emergency brake system during overspeed for the embodiment of Figure 3.

Figure 5: A schematic view of the overspeed emergency brake system with resonant characteristic components for another embodiment of the invention.

Figure 6: A schematic view of the overspeed emergency brake system in another embodiment in operational velocity.

Figure 7: A schematic view of the overspeed emergency brake system in the embodiment of Figure 6 in overspeed operation.

Figure 8: A schematic view of the overspeed emergency brake system in another embodiment in operational velocity.

Figure 9: A schematic view of the overspeed emergency brake system in the embodiment of Figure 8 in overspeed operation.

Description of the references in the figures:

[0020] The elements illustrated in the figures are numbered as follows:

1-Brake

system

10-

Elevator car

11-

Magnet

20-

Reaction surface

21-

Periodic feature

211-

Pitch

30-

Kinematic constraint element

31

Counterweight

32

Controlling element

33

Retracted limiting element

34

Extended limiting element

35

Pivot arm

36

Parallel link

37

Linear guide

B.

Overspeed emergency brake trigger

R:

Rope

GR:

Guide Rail

MF.

Magnetic force

V.

Elevator car velocity

NV.

Operational velocity of the elevator car

OV.

Overspeed velocity of the car

[0021] Brake system (1) of the invention shall be understood as an overspeed emergency brake system (1).

[0022] The disclosed brake system (1) of the invention comprises a transport cabin such as an elevator car (10) having an overspeed detector magnet (11), a reaction surface (20) and a converting means (a kinematic constraint elemet (30)) to convert the velocity of the elevator car (10) with respect to the reaction surface (20) to the force on the magnet (11) in a nonlinear way.

[0023] A brake actuation force is generated by the magnet (11) moving along the reaction surface (20), where the force is linear in speed as long as the mechanical parameters are kept constant. Mechanical parameters are defined by: Position of the overspeed detector magnet (11) on a kinematic constraint element (30). A converting means converts the speed-linear force into a strongly nonlinear force, thus keeping the mechanical losses low within the operational velocity region (normal operating speed region), while generating a sharply increasing force when the speed reaches the the overspeed condition or increases above it.

[0024] The elevator car (10) has two operation conditions normal operating condition where the elevator car (10) travels at design velocities, and overspeed condition where the elevator car (10) exceeds design speeds. Magnet (11), reaction surface (20) and a kinematic constraint element (30) are arranged such that a linear brake actuation force is generated at normal operating speeds of the elevator car (10), by moving the magnet (11) along the reaction surface (20) resulting a linear velocity-force relationship when the elevator car (10) is in a normal operation speed condition, and the kinematic constraint element (30) converts the linear speed-force relationship into a nonlinear speed-force relationship in an overspeed condition, thus keeping the mechanical losses low within the normal operating speeds, while generating a sharply increasing force in an overspeed condition.

[0025] In normal operation conditions, the brake actuation force generated by the magnet (11) moving along the reaction surface (20) due to Lenz's law is kept small because the overlapping area between the magnet (11) and the reaction surface (20) is small or because the excitation rate of the periodic element is out of the resonant region of the kinematic constraint element (30) and the magnet (11). However as overspeed condition is neared, the force suddenly becomes larger. The nonlinear increase in the brake actuation force is provided by an increase of overlap area between the magnet (11) and the reaction surface (20) due to the kinematic constraint element (30), or resonance of the kinematic constraint element (30) due to modulation of the brake actuation force by a periodic feature (21).

[0026] Invention comprises two main embodiments. In one main embodiment, the mechanical nonlinearity is achieved by increasing the overlap of the magnet (11) with the reaction surface (20) with respect to the speed, by a kinematic constraint element (30) and a restraining force imposed by a controlling element (32).

[0027] In the second main embodiment, the mechanical nonlinearity is achieved by modulating the brake actuation force with a periodic feature (21) (for example periodically placed slots or equivalents) of the reaction surface (20), at the mechanical resonance of the kinematic constraint element (30) and the magnet (11).

[0028] The elevator car (10) comprises a kinematic constraint element (30) and the overspeed detector magnet (11). The elevator car (10) or the kinematic constraint element (30) may comprise a counterweight (31) according to the applications of the invention.

[0029] The kinematic constraint element (30) is attached to the elevator car (10) defining the motion trajectory of the overspeed detector magnet (11). The kinematic constraint element (30) may comprise or may be any mechanism which defines the motion of the magnet (11) with respect to the elevator car (10) and the reaction surface (20).

[0030] Controlling element (32) is a suitable mechanical retraction spring in the preferred embodiment, of linear or rotational design. It can also be another element which provides a constant force to keep the magnet (11) at a stable position of the kinematic constraint element (30) until a desired counter-force of sufficient magnitude occurs. In the applications of the invention, reaction surface (20) can be any appropriate reaction surface (20), for example, ferromagnetic or non-ferromagnetic. Typically the guide rail (GR) that is already installed in the hoistway for the elevator car (10) can be used or an extra surface can be installed for that purpose. In another embodiment of the invention, reaction surface (20) can be some other suitable component over which an overspeed detector magnet (11) moves.

[0031] Nonlinear velocity-force relationship is realized where at the overspeed condition the force on the magnet (11) is sharply increased due either to the design of the kinematic constraint, or a periodic feature (21) on the reaction surface (20).

[0032] When set-up of the system (1) to the elevator car (10) is finished, the kinematic constraint element (30) is attached to the elevator car (10).

[0033] The brake system (1) has several embodiments.

[0034] In some embodiments of the invention, the kinematic constraint element (30) is attached to the elevator car (10), one end is fixed to the overspeed detector magnet (11) and the other end is fixed to the controlling element (32).The kinematic constraint element (30) comprises a counterweight (31) to prevent motion of the overspeed detection magnet (11) under acceleration forces (Figs 3, 4, 5, 6 and 7). Therefore, the invention is sensitive to velocity rather than accelerations and false triggering of overspeed emergency brake is avoided, for example at startup and stopping of the elevator car (10).

[0035] In some embodiments of the invention, the kinematic constraint element (30) defines the motion trajectory of the overspeed detector magnet (11). Brake system (1) also comprises a retracted limiting element (33). Retracted limiting element (33) is a part of the kinematic constraint element (30) in an alternative.The controlling element (32) is attached in such a way that the overspeed detector magnet (11) is attracted towards the retracted limiting element (33) during operational velocity (normal operating speed) to minimize force during normal operating velocity. The brake system (1) further comprises an extended limiting element (34). Extended limiting element (34) is comprised by the kinematic constraint element (30) in an alternative. The extended limiting element (34) maintains maximum brake force and displacement of the overspeed detector magnet (11) at overspeed condition (Figs 3, 4, 6, 7, 8 and 9). Overspeed condition is used interchangeably with overspeed threshold limit or predefined overspeed limit or predetermined overspeed limit or pre-set overspeed limit or calibrated overspeed limit or pre-defined overspeed trigger velocity in this document. These expressions shall be read as the same meaning.

[0036] In another embodiment of the invention the kinematic constraint element (30) is defines the motion trajectory of the overspeed detector magnet (11). The controlling element (32) is attached in such a way that the overspeed detector magnet (11) overlaps the periodic feature (21) on the reaction surface (20) during normal operation velocity and is able to make oscillatory motion along the direction of motion of elevator car (10).

[0037] The first main embodiment of the invention, preferably the kinematic constraint element (30) comprises a pivot arm (35) or parallel link (36) or linear guide (37) as described below.

[0038] In the first main embodiment of the invention the essence of the operation is disclosed herewith: Under normal operation conditions the overlapping surface area of the overspeed detector magnet (11) and the reaction surface (20) is smaller than the surface area of the magnet (11), and a system must be provided such that the overlapping surface area increases with increased force.

[0039] In the first alternative of the first main embodiment, the kinematic constraint element (30) is a pivot arm (35). In this embodiment, pivot arm (35) is fixed to the overspeed detector magnet (11) at one end and fixed to the controlling element (32) at the other end. After set-up of the system (1) to the elevator car (10) is finished, the end of the controlling element (32) which is not connected to the kinematic constraint element (30) is fixed to the elevator car (10) and the pivot point is attached to the elevator car (10). In this embodiment, the kinematic constraint element (30) comprises a counterweight (31) for countering the weight of the overspeed detector magnet (11) which serves to prevent acceleration forces from moving the overspeed detector magnet (11). In this embodiment system (1) comprises extended limiting element (34) and retracted limiting element (33). Retracted limiting element (33) causes pre-tension on the controlling element (32) and keeps the kinematic constraint element (30) at a resting position. Pivot arm (35) is connected with a suitable linkage having a specific mechanical advantage, to the trigger mechanism of the overspeed emergency brake (B), which is in turn, attached to the elevator car (10) (Fig 3 and 4).

[0040] Under normal operating conditions where the elevator car (10) moves within the operational velocity range, the kinematic constraint element (30) is held at its resting position due to the retracted limiting element (33) and controlling element (32), and the overspeed detector magnet (11) surface only partially overlaps the reaction surface (20). At the resting position, the force on the overspeed detector magnet (11) opposing the motion of the elevator car (10) due to Lenz's law is therefore small, and approximately linearly changes with the speed of the elevator car (10). This configuration is depicted in Fig. 3. Under normal operation conditions, the force generated on the overspeed detector magnet (11) is not sufficient to overcome the pre-tension on the controlling element (32) and the kinematic constraint element (30) remains at its resting position. The small overlap of the overspeed detector magnet (11) surface and reaction surface (20) at the resting position is the reason for the power efficiency of the invention (Fig 3).

[0041] If the speed of the elevator car (10) increases, the force on the overspeed detector magnet (11) also increases. As the speed increases towards the overspeed set point, the force increases beyond the pre-tension force of the controlling element (32) and the overspeed detector magnet (11) begins to move restrained by the kinematic constraint element (30), increasing the overlap area between the overspeed detector magnet (11) and the reaction surface (20). This movement may be a rotational movement of the pivot arm (35). The increased overlap causes the force to increase in a vicious cycle, and thereby the kinematic constraint element (30) eventually swings up to the extended limiting element (34) where the overspeed detector magnet (11) fully overlaps the reaction surface (20) and generates the maximum force and displacement. The increased force on the overspeed detector magnet (11) and displacement of the kinematic constraint element (30) at the pre-defined overspeed trigger velocity is sufficient to trigger the emergency brake (B), thereby arresting the motion of the elevator car (10). The configuration of the brake system (1) at overspeed condition is shown in Fig. 4. This nonlinear increase in the magnetic force with increasing speed causes a sudden transition from the normal operating condition to the overspeed condition, which allows for good precision in setting the overspeed velocity.

[0042] In the second alternative of the first main embodiment (Fig 6-7), kinematic constraint element (30) comprises a parallel link (36) i.e at least two parallel mechanical arms. In this embodiment, two mechanical arms and an overspeed detector magnet (11) is arranged such that the overspeed detector magnet (11) remains parallel to the reaction surface (20) on two mechanical arms during translation. This embodiment operates with the same operation principle described in the first alternative of the first main embodiment wherein just the magnet (11) does not rotate with respect to the reaction surface (20) as it translates.

[0043] A third alternative of the first main embodiment is illustrated in Figure 8 and Figure 9. This embodiment comprises a kinematic constraint element (30) consisting of at least one linear guide (37) (for example guide may comprise multitude of parallel guides). In this embodiment, the overspeed detector magnet (11) translates on a multitude of slanted parallel linear guides (37). These guides are attached to the elevator car (10) after set-up of the system (1) is realized on the elevator car (10). One movement limit of the linear guides (37) forms the retracted limiting element (33), and the other end is the extended limiting element (34). The overspeed detector magnet (11) is held towards the retracted limiting element (33) with suitable pre-tension using the controlling element (32), where its suface partially overlaps with the reaction surface (20). Linear guide (37) is connected with a suitable linkage having a specific mechanical advantage, to the trigger mechanism of the overspeed emergency brake (B), which is in turn, attached to the elevator car (10) (Fig 8 and 9). As overspeed condition is neared, the overspeed detector magnet (11) translates over the linear guides (37), and the overlapping surface between the overspeed detector magnet (11) and the reaction surface (20) increases. The principle of operation is the same as explained for the above disclosed embodiment of Figures (3, 4, 6 and 7).

[0044] The operation detailed so far is effective if the elevator car (10) overspeeds in the down direction. If the specific installation of an overspeed emergency brake, is requires for the elevator car (10) which overspeeds in the up direction (such as elevator cars (10) with a counterweight, a mechanism which is symmetrical around a horizontal line to that explained above, also needs to be implemented. A skilled person would be able to implement these symmetrical embodiments easily and these embodiments should be also regarded to be in the scope of the invention.

[0045] The kinematic constraint element (30) defining the movement of the overspeed detector magnet (11) during overspeed can be different as described above, as long as the essence of operation is the same.

[0046] The first main embodiment of the invention alleviates Problem-1 because during normal operation conditions, the overspeed detector magnet (11) only partially overlaps the reaction surface (20), which causes the opposing force on the overspeed detector magnet (11) to be greatly reduced. It alleviates Problem-2 because the proposed mechanism is activated by a positive feedback force at a given overspeed velocity whereas the force on the overspeed detector magnet (11) increases, the overspeed detector magnet (11) is constrained to move in a direction which increases the overlapping surface area between the overspeed detector magnet (11) and the reaction surface (20), which further increases the force. The structure of the system (1) including the kinematics, mechanical advantage, geometry and materials, determine the speed at which the trigger linkage will be activated. This can be calculated using normal engineering principles. The overspeed emergency brake (B) trigger mechanism and brake mechanism itself are conventional systems which can be used as is or with small modifications.

[0047] The second main embodiment of the invention is depicted below:
The system comprises a kinematic constraint element (30) having a pivot arm (35). In this embodiment, pivot arm (35) is fixed to the overspeed detector magnet (11) at one end and fixed to the controlling element (32) at the other end. The end of the controlling element (32) which is not connected to the kinematic constraint element (30) is fixed to the elevator car (10) when the system (1) installation to the elevator car (10) is made. In this embodiment, the kinematic constraint element (30) comprises a counterweight (31) for countering the weight of the overspeed detector magnet (11) which serves to prevent acceleration forces from moving the overspeed detector magnet (11). The controlling element (32) is attached in such a way that the overspeed detector magnet (11) overlaps the periodic feature (21) on the reaction surface (20) during normal operation velocity and is able to make oscillatory motion along the direction of motion of elevator car (10). Pivot arm (35) is connected with a suitable linkage having a specific mechanical advantage, to the trigger mechanism of the overspeed emergency brake (B), which is in turn, attached to the elevator car (10) (Fig 5).

[0048] In this embodiment, the reaction surface (20) comprises at least one periodic feature (21). The periodic feature (21) comprises slits, or horizontal slits, or parallel horizontal slits, or non-straight edge along its length. Or the periodic feature (21) comprises similar periodic deviations from a straight line or smooth surface or homogeneous composition, along its length. Reaction surface (20) also comprises at least one pitch (211) which defines the repetition distance of the periodic feature (21).

[0049] In this embodiment, during movement of the elevator car (10), the force on the overspeed detector magnet (11) is modulated by the periodic features (21) at a certain frequency which is related to periodic feature pitch (211) and elevator car (10) velocity. The mechanical properties of the kinematic constraint element (30), the controlling element (32) and the magnet (11) is such that their resonance frequency coincides with the specific frequency which is produced by the elevator car (10) running at the desired overspeed velocity value. At the predefined overspeed velocity of the elevator car (10), therefore, the kinematic constraint element (30) will start to resonate at large amplitude, trigger the overspeed emergency brake (B) and arrest the movement of the elevator car (10). During normal operation the resonance does not occur and the overspeed emergency brake is not triggered.

[0050] This embodiment is also advantageous compared to previous prior art, because it can be tuned to the specific overspeed velocity by modifying the dimensions of the deviations, the characteristics of the mechanical components, such as the moment of inertia of the kinematic constraint element (30) and/or spring constant of the controlling element (32) and/or pitch (211) etc.

[0051] The brake system (1) proposed in the invention, is better in both of these areas, where the force generated at normal operating range is smaller than the pior art applications, which means better power efficiency. Second, elevator car (10) velocity- system force response isnonlinear at overspeed condition. Therefore, by designing the mechanical components properly, it is possible to set a precise triggering velocity for the overspeed limit. Overspeed emergency brake system (1) enables an elevator car (10) (eg: a passenger elevator) overspeed emergency brake (B) system which is completely contained within the elevator car (10) itself. The advantages of the invention are:

• Overspeed detection based on magnetic principles is provided thereby making the invention self contained in the elevator car (10).
• Completely mechanical overspeed emergency detection and brake activation is provided.
• Suitable for use in multi-car elevator systems.
• It provides higher efficiency. This mechanism does not produce a force proportional to elevator car (10) velocity.
• It provides, precise setting of overspeed emergency limit of velocity of the elevator car (10).
• The system (1) does not require special maintenance.
• It provides low implementation cost.
• It is simple to implement.
• In the system, calibration is necessary only at the factory for initial settings.

[0052] The invention is not limited to the disclosed embodiments above; a skilled person in the art can produce different embodiments of the invention easily. They should be evaluated within the scope of protection demanded with claims.

Claims

1. An overspeed emergency brake system (1) for elevator cars (10), comprising an overspeed detector magnet (11) generating a brake actuation force and a kinematic constraint element (30) guiding movement of the overspeed detector magnet (11) with respect to a reaction surface (20), characterized in that; the overspeed detector magnet (11), the reaction surface (20) and the kinematic constraint element (30) are arranged such that;
the kinematic constraint element (30) is attached to the elevator car (10) for defining the motion of the overspeed detector magnet (11) with respect to the elevator car (10) and the reaction surface (20);

- a linear brake actuation force is generated at a normal operating speed condition due to the movement of the overspeed detector magnet (11) along the reaction surface (20); the overspeed detector magnet (11) and the reaction surface (20) are linked with a magnetic force where a surface of the overspeed detector magnet (11) partially overlaps with the reaction surface (20), or excitation rate caused by a periodic feature (21) of the reaction surface (20) is out of a resonant region of the kinematic constraint element (30) and the overspeed detector magnet (11); and

- the kinematic constraint element (30) converts the linear speed-force relationship into a nonlinear speed-force relationship in an overspeed condition, while generating a sharply increasing force for triggering the overspeed emergency brake (B);

where the overspeed detector magnet (11) is translated with respect to the kinematic constraint element (30) or the overspeed detector magnet (11) is moved across the reaction surface (20) due to the kinematic constraint element (30) whereby the surface of the overspeed detector magnet (11) is completely overlapped with the reaction surface (20), or

where the kinematic constraint element (30) is started to resonate at an amplitude which triggers the overspeed emergency brake (B) by modulating the brake actuation force by a periodic feature (21).

2. A system (1) according to claim 1, further comprising a controlling element (32) which provides a constant force to keep the overspeed detector magnet (11) in a stable position of the kinematic constraint element (30) until a desired counter - force of sufficient magnitude occurs wherein

- a kinematic constraint element (30) defines the motion trajectory of an overspeed detector magnet (11), wherein a controlling element (32) applies a pre-tension force to hold the overspeed detector magnet (11) towards a retracted limiting element (33) in the normal operating speed condition,

- in case of overspeed condition where a transition region defined by the magnetic force overcoming a pre-determined holding force of the controlling element (32) is reached and causes the overspeed detector magnet (11) to begin moving restrained by the kinematic constraint element (30) or to start translating across the reaction surface (20) due to the kinematic constraint element (30) increasing the overlapping area between the overspeed detector magnet (11) and the reaction surface (20) thereby increasing the magnetic force even more, or causes the kinematic constraint element (30) to start resonating for triggering an overspeed emergency brake (B) at a pre-determined overspeed velocity limit,

- when the pre-determined overspeed velocity limit is exceeded the transition region ends, the maximum force and displacement is generated whereby the magnet (11) surface completely overlaps the reaction surface (20) and the overspeed detector magnet (11) is restrained by an extended limiting element (34).

3. A system (1) according to claim 1 or 2 further comprising a counterweight (31) for countering the weight of the overspeed detector magnet (11) which serves to prevent acceleration forces from moving the overspeed detector magnet (11).

4. A system (1) according to any of the claims 2 or 3 , wherein the kinematic constraint element (30) is a pivot arm (35), and fixed to the overspeed detector magnet (11) at one end and fixed to the controlling element (32) at the other end, where the overspeed detector magnet (11) is moved across the reaction surface (20) due to the pivot arm (35) whereby surface of the overspeed detector magnet (11) is completely overlapped with the reaction surface (20) in an overspeed condition.

5. A system (1) according to any of the claims 1 to 3 wherein kinematic constraint element (30) comprises a parallel link (36), and the overspeed detector magnet (11) is arranged such that the overspeed detector magnet (11) remains parallel to the reaction surface (20) on two mechanical arms of the parallel link (36) during translation when the system is operating, where in an overspeed condition, the overspeed detector magnet (11) is translated across the reaction surface (20) due to the kinematic constraint element (30) whereby the surface of the overspeed detector magnet (11) is completely overlapped with the reaction surface (20).

6. A system (1) according to Claim 2 wherein the kinematic constraint element (30) consists of at least one linear guide (37) or multitude of parallel guides.

7. A system (1) according to Claim 6 wherein the overspeed detector magnet (11), the kinematic constraint element (30) and the controlling element (32) are arranged such that the overspeed detector magnet (11) translates on a multitude of slanted parallel linear guides (37) and one movement limit end of the linear guides (37) forms the retracted limiting element (33), and the other end is the extended limiting element (34) wherein, the overspeed detector magnet (11) is held towards the retracted limiting element (33) with suitable pre-tension using the controlling element (32), where the surface of the overspeed detector magnet (11) partially overlaps with the reaction surface (20) at the normal operating speed condition; and where the surface of the overspeed detector the magnet (11) completely overlaps with the reaction surface (20) in an overspeed condition.

8. A system (1) according to Claim 2 or 3 wherein, the kinematic constraint element (30) and the overspeed detector magnet (11) are arranged such that their resonance frequency coincides with a specific frequency to be produced by an elevator car (10) running at the predefined overspeed velocity limit, causing the kinematic constraint element (30), the controlling element (32) and the overspeed detector magnet (11) to resonate at a larger amplitude than normal operation speed condition to trigger the overspeed emergency brake (B) in an overspeed condition and arrest the movement of the elevator car (10), wherein during normal operation speed condition the resonance does not occur and the overspeed emergency brake is not being triggered.

9. A system (1) according to claim 8, wherein the kinematic constraint element (30) comprises a pivot arm (35) for connecting with a suitable linkage having a specific mechanical advantage, to a trigger mechanism of the overspeed emergency brake (B).

10. A system (1) according to Claim 8 or 9, wherein the reaction surface (20) comprises at least one periodic feature (21), arranged in such a way that the overspeed detector magnet (11) is able to overlap the periodic feature (21) on said reaction surface (20) during normal operation condition and is able to make oscillatory motion along the direction of motion of the elevator car (10) and the mechanical nonlinearity is achieved by modulating the brake actuation force with the periodic feature (21).

11. A system (1) according to Claim 10, wherein the periodic feature (21) comprises slits, or periodically placed slots or horizontal slits, or parallel horizontal slits, or non-straight edge along its length.

12. A system (1) according to Claim 10 or 11, wherein the periodic feature (21) comprises periodic deviations from a straight line or smooth surface or homogeneous composition, along its length.

13. A system (1) according to any one of the claims 10 to 12, wherein the reaction surface (20) further comprises at least one pitch (211) which defines the repetition distance of the periodic feature (21) for modulating the force on the overspeed detector magnet (11) at a certain frequency during movement of the elevator car (10),

14. A system (1) according to any one of the previous claims 2 to 13, wherein the controlling element (32) is a spring of linear or rotational design or a device which generates larger force or constant force as it extends.

Ansprüche

1. Notbremssystem (1) bei überhöhter Geschwindigkeit von Aufzugskabinen (10), mit einem Detektormagneten (11) für überhöhte Geschwindigkeit, welcher eine Bremsbetätigungskraft erzeugt, und mit einem kinematischen Begrenzungselement (30), welches die Bewegung des Detektormagneten (11) für überhöhte Geschwindigkeit relativ zu einer Reaktionsfläche (20) führt, dadurch gekennzeichnet, dass der Detektormagnet (11) für überhöhte Geschwindigkeit, die Reaktionsfläche (20) und das kinematische Begrenzungselement (30) derart angeordnet sind, dass
das kinematische Begrenzungselement (30) an der Aufzugskabine (10) angebracht ist, um die Bewegung des Detektormagneten (11) für überhöhte Geschwindigkeit bezüglich der Aufzugskabine (10) und der Reaktionsfläche (20) zu bestimmen,

- eine lineare Bremsbetätigungskraft aufgrund der Bewegung des Detektormagneten (11) für überhöhte Geschwindigkeit entlang der Reaktionsfläche (20) unter Bedingungen einer normalen Betriebsgeschwindigkeit erzeugt wird; der Detektormagnet (11) für überhöhte Geschwindigkeit und die Reaktionsfläche (20) über eine magnetische Kraft miteinander in Verbindung stehen, wobei eine Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit teilweise mit der Reaktionsfläche (20) überlappt, oder eine Anregungsrate, welche durch ein periodisches Merkmal (21) der Reaktionsfläche (20) bewirkt wird, außerhalb eines Resonanzbereiches des kinematischen Begrenzungselementes (30) und des Detektormagneten (11) für überhöhte Geschwindigkeit liegt; und

- das kinematische Begrenzungselement (30) bei einem Zustand mit überhöhter Geschwindigkeit die lineare Beziehung zwischen Geschwindigkeit und Kraft in eine nichtlineare Beziehung zwischen Geschwindigkeit und Kraft umwandelt, wobei eine drastisch ansteigende Kraft für das Auslösen der Notbremse (B) für überhöhte Geschwindigkeit erzeugt wird;

wobei der Detektormagnet (11) für überhöhte Geschwindigkeit bezüglich des kinematischen Begrenzungselementes (30) verschoben wird oder der Detektormagnet (11) für überhöhte Geschwindigkeit aufgrund des kinematischen Begrenzungselementes (30) über die Reaktionsfläche (20) hinwegbewegt wird, wobei die Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit vollständig mit der Reaktionsfläche (20) in Überlappung gebracht wird, oder

wobei das kinematische Begrenzungselement (30) veranlasst wird, mit einer Amplitude in Resonanz zu kommen, welche die Notbremse (B) für überhöhte Geschwindigkeit auslöst, indem die Bremsbetätigungskraft durch ein periodisches Merkmal (21) moduliert wird.

2. System (1) nach Anspruch 1, welches weiterhin ein Steuerungselement (32) aufweist, welches eine konstante Kraft bereitstellt, um den Detektormagneten (11) für überhöhte Geschwindigkeit in einer stabilen Position bezüglich des kinematischen Begrenzungselementes (30) zu halten, bis eine gewünschte Gegenkraft ausreichender Größe auftritt, wobei

- ein kinematisches Begrenzungselement (30) die Bewegungsbahn eines Detektormagneten (11) für überhöhte Geschwindigkeit definiert, wobei ein Steuerungselement (32) eine Vorspannungskraft aufbringt, um den Detektormagneten (11) für überhöhte Geschwindigkeit bei Bedingungen einer normalen Betriebsgeschwindigkeit in Richtung eines zurückgezogenen Begrenzungselementes (33) zu halten,

- im Falle eines Zustandes mit überhöhter Geschwindigkeit, in welchem ein Übergangsbereich, welcher durch die magnetische Kraft definiert wird, die eine vorbestimmte Haltekraft des Steuerungselementes (32) überschreitet, erreicht wird und bewirkt, dass der Detektormagnet (11) für überhöhte Geschwindigkeit beginnt sich begrenzt durch das kinematische Begrenzungselement (30) zu bewegen, oder damit beginnt, sich wegen des kinematischen Begrenzungselementes (30) über die Reaktionsfläche (20) hinweg zu bewegen, was die Überlappungsfläche zwischen dem Detektormagneten für überhöhte Geschwindigkeit und der Reaktionsfläche vergrößert und damit die Magnetkraft noch weiter erhöht, oder bewirkt, dass das kinematische Begrenzungselement (30) damit beginnt, in Resonanz zu kommen, um eine Notbremse (B) für überhöhte Geschwindigkeit bei einem vorbestimmten Grenzwert für überhöhte Geschwindigkeit auszulösen,

- wenn der vorbestimmte Grenzwert einer überhöhten Geschwindigkeit über die Enden des Übergangsbereiches hinaus überschritten wird, die maximale Kraft und Verschiebung erzeugt wird, wodurch die Fläche des Magneten (11) vollständig mit der Reaktionsfläche (20) überlappt und der Detektormagnet (11) für überhöhte Geschwindigkeit durch ein ausgefahrenes Begrenzungselement (34) begrenzt wird.

3. System (1) nach Anspruch 1 oder 2, welches weiterhin ein Gegengewicht (21) für den Ausgleich des Gewichtes des Detektormagneten (11) für überhöhte Geschwindigkeit aufweist, welches dazu dient zu verhindern, dass Beschleunigungskräfte den Detektormagneten (11) für überhöhte Geschwindigkeit bewegen.

4. System (1) nach einem der Ansprüche 2 oder 3, wobei das kinematische Begrenzungselement (30) ein Schwenkarm (35) ist, welcher an einem Ende an dem Detektormagneten (11) für überhöhte Geschwindigkeit befestigt ist und an dem anderen Ende an dem Steuerungselement (32) befestigt ist, wobei der Detektormagnet (11) durch den Schwenkarm (35) über die Reaktionsfläche (20) hinweg bewegt wird, wobei die Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit in einem Zustand bei erhöhter Geschwindigkeit mit der Reaktionsfläche (20) vollständig in Überlappung gebracht wird.

5. System (1) nach einem der Ansprüche 1 bis 3, wobei das kinematische Begrenzungselement (30) ein Parallelogrammglied (36) aufweist und der Detektormagnet (11) für überhöhte Geschwindigkeit derart ausgelegt ist, dass der Detektormagnet (11) bei einer Verschiebung im Betrieb des Systems an zwei mechanischen Armen des Parallelogrammgliedes (36) parallel zu der Reaktionsfläche (20) bleibt, wobei der Detektormagnet (11) für überhöhte Geschwindigkeit bei einem Zustand mit überhöhter Geschwindigkeit durch das kinematische Begrenzungselement (30) über die Reaktionsfläche (20) hinweg verschoben wird, wobei die Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit in vollständige Überlappung mit der Reaktionsfläche (20) gebracht wird.

6. System (1) nach Anspruch 2, wobei das kinematische Begrenzungselement (30) aus zumindest einer linearen Führung (37) oder aus einer Mehrzahl von parallelen Führungen besteht.

7. System (1) nach Anspruch 6, wobei der Detektormagnet (11) für überhöhte Geschwindigkeit, das kinematische Begrenzungselement (30) und das Steuerungselement (32) derart angeordnet sind, dass der Detektormagnet (11) für überhöhte Geschwindigkeit sich auf einer Mehrzahl von geneigten parallelen Linearführungen (37) verschiebt und dass ein Bewegungsbegrenzungsende der Linearführungen (37) das zurückgezogene Begrenzungselement (33) bildet und das andere Ende das ausgefahrene Begrenzungselement (34) bildet, wobei der Detektormagnet (11) für überhöhte Geschwindigkeit mit einer geeigneten Vorspannung unter Verwendung des Steuerungselementes (32) in Richtung des zurückgezogenen Begrenzungselementes (33) gehalten wird, wobei die Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit unter Bedingungen einer normalen Betriebsgeschwindigkeit mit der Reaktionsfläche (20) teilweise überlappt, und wobei die Oberfläche des Detektormagneten (11) für überhöhte Geschwindigkeit bei dem Zustand mit überhöhter Geschwindigkeit vollständig mit der Reaktionsfläche (20) überlappt.

8. System (1) nach Anspruch 2 oder 3, wobei das kinematische Begrenzungselement (30) und der Detektormagnet (11) für überhöhte Geschwindigkeit derart ausgelegt sind, dass ihre Resonanzfrequenz mit einer speziellen Frequenz zusammenfällt, die durch eine Aufzugskabine (10), die mit dem vorbestimmten Grenzwert für überhöhte Geschwindigkeit läuft, erzeugt wird, was bewirkt, dass das kinematische Begrenzungselement (30), das Steuerungselement (32) und der Detektormagnet (11) für überhöhte Geschwindigkeit mit einer höheren Amplitude in Resonanz sind, als in einem Zustand mit normaler Betriebsgeschwindigkeit, um so in einem Zustand überhöhter Geschwindigkeit die Notbremse (11) für überhöhte Geschwindigkeit auszulösen und die Bewegung der Aufzugskabine (10) zu stoppen, wobei während eines Zustandes mit normaler Betriebsgeschwindigkeit die Resonanz nicht auftritt und die Notbremse für überhöhte Geschwindigkeit nicht ausgelöst wird.

9. System (1) nach Anspruch 8, wobei das kinematische Begrenzungselement (30) einen Schwenkarm (35) aufweist für die Verbindung mit geeigneten Verbindungsgliedern, die eine spezielle mechanische Hebelverstärkung haben, um den Mechanismus der Notbremse (B) bei überhöhter Geschwindigkeit auszulösen.

10. System (1) nach Anspruch 8 oder 9, wobei die Reaktionsfläche (20) zumindest ein periodisches Merkmal (21) aufweist, welches in der Weise ausgelegt ist, dass der Detektormagnet (11) für überhöhte Geschwindigkeit in der Lage ist, mit dem periodischen Merkmal (21) auf der Reaktionsfläche (20) während eines normalen Betriebszustandes zu überlappen, und in der Lage ist, eine oszillatorische Bewegung entlang der Bewegungsrichtung der Aufzugskabine (10) auszuführen, und wobei die mechanische Nichtlinearität erreicht wird, indem die Bremsbetätigungskraft durch das periodische Merkmal (21) moduliert wird.

11. System (1) nach Anspruch 10, wobei das periodische Merkmal (21) Schlitze oder periodisch angebrachte Schlitze oder horizontale Schlitze oder parallele horizontale Schlitze oder nicht geradlinige Kanten entlang seiner Länge aufweist.

12. System (1) nach Anspruch 10 oder 11, wobei das periodische Merkmal (21) periodische Abweichungen von einer geraden Linie oder einer glatten Oberfläche oder einer homogenen Zusammensetzung über die Länge hinweg aufweist.

13. System (1) nach einem der Ansprüche 10 bis 12, wobei die Reaktionsfläche (20) zumindest einen Wiederholabstand (211) aufweist, welches den Wiederholabstand des periodischen Merkmals (21) festlegt, um während der Bewegung der Aufzugskabine (10) die Kraft auf den Detektormagneten (11) für überhöhte Geschwindigkeit mit einer bestimmten Frequenz zu modulieren.

14. System (1) nach einem der vorstehenden Ansprüche 2 bis 13, wobei das Steuerungselement (32) eine lineare Feder oder Torsionsfeder oder ein Gerät ist, welches eine größere Kraft oder konstante Kraft erzeugt, wenn sie sich dehnt.

Revendications

1. Système de freinage d'urgence en cas de survitesse (1) pour des cabines d'ascenseur (10), comprenant un aimant détecteur de survitesse (11) générant une force d'actionnement de frein et un élément de contrainte cinématique (30) guidant un mouvement de l'aimant détecteur de survitesse (11) par rapport à une surface de réaction (20), caractérisé par le fait que : l'aimant détecteur de survitesse (11), la surface de réaction (20) et l'élément de contrainte cinématique (30) sont disposés de telle sorte que :

- l'élément de contrainte cinématique (30) est attaché à la cabine d'ascenseur (10) pour définir le mouvement de l'aimant détecteur de survitesse (11) par rapport à la cabine d'ascenseur (10) et à la surface de réaction (20) ;

- une force d'actionnement de frein linéaire est générée à une condition de vitesse de fonctionnement normale, en raison du mouvement de l'aimant détecteur de survitesse (11) le long de la surface de réaction (20) ; l'aimant détecteur de survitesse (11) et la surface de réaction (20) sont liés par une force magnétique où une surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent partiellement, ou la fréquence d'excitation provoquée par une caractéristique périodique (21) de la surface de réaction est hors d'une région de résonance de l'élément de contrainte cinématique (30) et de l'aimant détecteur de survitesse (11) ; et

- l'élément de contrainte cinématique (30) convertit la relation vitesse-force linéaire en une relation vitesse-force non linéaire dans une condition de survitesse, tout en générant une force augmentant brusquement pour déclencher le frein d'urgence en cas de survitesse (B) ;

où l'aimant détecteur de survitesse (11) est translaté par rapport à l'élément de contrainte cinématique (30) ou l'aimant détecteur de survitesse (11) est déplacé à travers la surface de réaction (20) en raison de l'élément de contrainte cinématique (30), ce par quoi la surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent complètement, ou

où l'élément de contrainte cinématique (30) est amené à commencer à résonner à une amplitude qui déclenche le frein d'urgence en cas de survitesse (B) par modulation de la force d'actionnement de frein par une caractéristique périodique (21).

2. Système (1) selon la revendication 1, comprenant en outre un élément de commande (32) qui fournit une force constante pour maintenir l'aimant détecteur de survitesse (11) dans une position stable de l'élément de contrainte cinématique (30) jusqu'à ce qu'une force antagoniste souhaitée d'amplitude suffisante se produise, dans lequel :

- un élément de contrainte cinématique (30) définit la trajectoire de mouvement d'un aimant détecteur de survitesse (11), un élément de commande (32) appliquant une force de pré-tension pour maintenir l'aimant détecteur de survitesse (11) vers un élément de limitation rétracté (33) dans la condition de vitesse de fonctionnement normale,

- en cas de condition de survitesse, où une région de transition définie par la force magnétique dépassant une force de maintien prédéterminée de l'élément de commande (32) est atteinte et amène l'aimant détecteur de survitesse (11) à commencer à se déplacer contraint par l'élément de contrainte cinématique (30) ou à commencer à se translater à travers la surface de réaction (20) en raison de l'élément de contrainte cinématique (30) augmentant la zone de chevauchement entre l'aimant détecteur de survitesse (11) et la surface de réaction (20), augmentant ainsi encore plus la force magnétique, ou amène l'élément de contrainte cinématique (30) à commencer à résonner pour déclencher un frein d'urgence en cas de survitesse (B) à une limite de vitesse de survitesse prédéterminée,

- lorsque la limite de vitesse de survitesse prédéterminée est dépassée, la région de transition se termine, la force maximale et le déplacement maximal sont générés, ce par quoi la surface de l'aimant (11) chevauche complètement la surface de réaction (20) et l'aimant détecteur de survitesse (11) est contraint par un élément de limitation étendu (34).

3. Système (1) selon l'une des revendications 1 ou 2 comprenant en outre un contrepoids (31) pour s'opposer au poids de l'aimant détecteur de survitesse (11) qui sert à empêcher les forces d'accélération de déplacer l'aimant détecteur de survitesse (11).

4. Système (1) selon l'une des revendications 2 ou 3, dans lequel l'élément de contrainte cinématique (30) est un bras pivotant (35), et est fixé à l'aimant détecteur de survitesse (11) à une extrémité et fixé à l'élément de commande (32) à l'autre extrémité, où l'aimant détecteur de survitesse (11) est déplacé à travers la surface de réaction (20) en raison du bras pivotant (35), ce par quoi la surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent complètement dans une condition de survitesse.

5. Système (1) selon l'une quelconque des revendications 1 à 3, dans lequel l'élément de contrainte cinématique (30) comprend une liaison parallèle (36), et l'aimant détecteur de survitesse (11) est disposé de telle sorte que l'aimant détecteur de survitesse (11) reste parallèle à la surface de réaction (20) sur deux bras mécaniques de la liaison parallèle (36) pendant la translation lorsque le système fonctionne, où, dans une condition de survitesse, l'aimant détecteur de survitesse est translaté à travers la surface de réaction (20) en raison de l'élément de contrainte cinématique (30), ce par quoi la surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent complètement.

6. Système (1) selon la revendication 2, dans lequel l'élément de contrainte cinématique (30) consiste en au moins un guide linéaire (37) ou en une pluralité de guides parallèles.

7. Système (1) selon la revendication 6, dans lequel l'aimant détecteur de survitesse (11), l'élément de contrainte cinématique (30) et l'élément de commande (32) sont disposés de telle sorte que l'aimant détecteur de survitesse (11) se translate sur une pluralité de guides linéaires parallèles inclinés (37) et une extrémité de limite de mouvement des guides linéaires (37) forme l'élément de limitation rétracté (33), et l'autre extrémité est l'élément de limitation étendu (34), dans lequel l'aimant détecteur de survitesse (11) est maintenu vers l'élément de limitation rétracté (33) par une pré-tension appropriée à l'aide de l'élément de commande (32), où la surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent partiellement à la condition de vitesse de fonctionnement normale ; et où la surface de l'aimant détecteur de survitesse (11) et la surface de réaction (20) se chevauchent complètement dans une condition de survitesse.

8. Système (1) selon l'une des revendications 2 ou 3, dans lequel l'élément de contrainte cinématique (30) et l'aimant détecteur de survitesse (11) sont disposés de telle sorte que leur fréquence de résonance coïncide avec une fréquence spécifique devant être produite par une cabine d'ascenseur (10) fonctionnant à la limite de vitesse de survitesse prédéfinie, amenant l'élément de contrainte cinématique (30), l'élément de commande (32) et l'aimant détecteur de survitesse (11) à résonner à une amplitude plus grande que la condition de vitesse de fonctionnement normale pour déclencher le frein d'urgence en cas de survitesse (B) dans une condition de survitesse et arrêter le mouvement de la cabine d'ascenseur (10), dans lequel, pendant la condition de vitesse de fonctionnement normale, la résonance ne se produit pas et le frein d'urgence de survitesse n'est pas déclenché.

9. Système (1) selon la revendication 8, dans lequel l'élément de contrainte cinématique (30) comprend un bras pivotant (35) pour se connecter, par une liaison appropriée ayant un avantage mécanique spécifique, à un mécanisme de déclenchement du frein d'urgence en cas de survitesse (B).

10. Système (1) selon l'une des revendications 8 ou 9, dans lequel la surface de réaction (20) comprend au moins une caractéristique périodique (21), disposée d'une manière telle que l'aimant détecteur de survitesse (11) est capable de chevaucher la caractéristique périodique (21) sur ladite surface de réaction (20) pendant une condition de fonctionnement normal et est capable d'effectuer un mouvement oscillatoire le long de la direction de mouvement de la cabine d'ascenseur (10) et la non-linéarité mécanique est obtenue par modulation de la force d'actionnement de frein avec la caractéristique périodique (21).

11. Système (1) selon la revendication 10, dans lequel la caractéristique périodique (21) comprend des fentes, ou des fentes placées périodiquement ou des fentes horizontales, ou des fentes horizontales parallèles, ou un bord non droit le long de sa longueur.

12. Système (1) selon l'une des revendications 10 ou 11, dans lequel la caractéristique périodique (21) comprend des écarts périodiques par rapport à une ligne droite ou une surface lisse ou une composition homogène, le long de sa longueur.

13. Système (1) selon l'une quelconque des revendications 10 à 12, dans lequel la surface de réaction (20) comprend également au moins un pas (211) qui définit la distance de répétition de la caractéristique périodique (21) pour moduler la force sur l'aimant détecteur de survitesse (11) à une certaine fréquence pendant le mouvement de la cabine d'ascenseur (10).

14. Système (1) selon l'une quelconque des revendications précédentes 2 à 13, dans lequel l'élément de commande (32) est un ressort de conception linéaire ou tournante ou un dispositif qui génère une plus grande force ou une force constante lorsqu'il s'étend.

Drawing