HK1139372B - Unintended movement governor - Google Patents

Description

Unintended movement governor

Technical Field

The invention relates to an electronic unintended movement governor and a method for controlling the same.

Background

Since the elevator system is to be safe for the passengers, the movement of the elevator car in the elevator shaft must be controlled in all operating situations. In different changing operating situations, the movement of the elevator car must always be limited so that it remains in the area defined as safe for the particular operating situation. For this reason, on the one hand, different limit values for the permitted movement of the elevator car must be defined, and on the other hand, it must be ensured that the elevator car remains in the operating environment defined by these limits.

The elevator system contains numerous prior-art safety devices and sensors for monitoring the movement of the elevator car and for ensuring safety. In normal operating situations the control system of the elevator handles the drive of the elevator between floors. For this purpose, the elevator shaft contains sensors which indicate the position of the floor. During normal driving, in acceleration and deceleration, the control system of the elevator ensures that e.g. the speed of the elevator decreases and the elevator stops at the position of the correct floor. The control system also stops the elevator smoothly at the terminal floor. A conventional terminal slowdown (NTS) handles the smooth stopping of the elevator at the terminal floor if the conventional stopping of the elevator by using the control system does not work. For this purpose an additional control unit is added to the control system of the elevator, which checks the operation of the normal travel control and, when it detects that the control does not start decelerating normally when approaching the terminal floor, skips the normal travel control and manages the stopping of the elevator at the terminal floor.

A mechanical overspeed governor (OSG) can be used as a safety device. The overspeed governor monitors the speed of the elevator car in the elevator shaft and, if the speed of the elevator car exceeds a certain preset limit value, the overspeed governor opens the safety circuit of the elevator, in which case the machinery brake is active. The elevator contains a safety circuit which is cut off if any of the switches connected to it is open. If the overspeed still increases from the previous, the overspeed governor uses safety gears associated with the elevator car, the wedges of which grip (grip) the guide rails of the elevator and prevent movement of the elevator car. In other words, if the rope or rope suspension fails and the elevator car starts to fall freely, the safety gear wedges and grips.

When the elevator car is near a landing (landing) and the elevator car doors and landing doors are open, it must be ensured that the elevator car cannot be removed from the landing. In this case, the movement of the elevator car will cause a shearing (shearing) risk between the elevator car and the opening of the landing door. Such a dangerous situation may arise, for example, when a machinery brake fails, or when the rope slips on the traction sheave. For this reason, a so-called anti-creep device is added to the elevator, which is based on preventing the rotation of the wheels of the mechanical overspeed governor when the elevator car reaches the landing, e.g. with a wedge, so that when the wheels are rotated e.g. 90 degrees, the wedge locks the wheels and causes a grip on the elevator car. The control system of the elevator always controls the wedges to be in place when the elevator car arrives at the landing.

Publication ES2129088T discloses a prior-art arrangement with which the elevator car is stopped by locking the wheel of the mechanical overspeed governor so that the gripping function is activated. However, the disadvantages of this device are: since the wheel of the overspeed governor is perhaps rotated 90 degrees before the stopping function is activated, the elevator car is perhaps moved about 200mm before it stops. In this case, the risk of shearing continues to exist.

Overspeed can also be monitored electrically. A solution is known, for example, from publication WO00/39015, in which an electronic overspeed monitoring appliance receives a signal indicating the speed of the car, compares the speed of the car with speed limit data stored in a memory of the monitoring appliance and, if necessary, generates an activation signal, by using which the brake of the elevator can be activated.

Near the end of the elevator shaft is an end limit switch. When the elevator car reaches the end limit switch, a ramp (ramp) associated with the elevator car forces the end limit switch to open and the safety circuit of the elevator is cut off, in which case the machinery brake of the elevator operates and the main contactors of the elevator open.

If the elevator continues a few centimeters forward from the end limit switch, the car (or, correspondingly, counterweight) collides with the buffer, which yields and eventually stops the elevator.

The agencies of different countries have different regulations regarding elevator safety. The basic principle is as follows: the elevator must contain some kind of safety system that is able to stop the elevator in a fault situation. For example, according to the elevator directive 95/16/EC proposed by the european union, the elevator must contain an overspeed governor, as well as a speed monitoring system. The elevator does not reach uncontrolled acceleration movements and uncontrolled deceleration movements. Furthermore, the following must be avoided: in which the elevator car starts to slide out of the landing zone when the door opens, e.g. due to rope slip or a fault situation of the machinery brake.

Publication WO 2006/082275a2 presents an electronic unintended movement governor, which comprises two separate controls for controlling the stopping appliance of the elevator car, namely: a first controller for immediately controlling a stopping appliance of the elevator car as soon as the elevator car exceeds a limit value of the allowed maximum speed; and a second controller for controlling a stopping device of the elevator car based on the received door zone information.

Publication JP 5-70048A presents an electronic unintended movement governor, in which the limit values for the permitted movement of the elevator car comprise limit values for the distance traveled by the elevator car and for the time delay. The electronic unintended movement governor comprises means for determining the distance traveled by the elevator car, and a control for stopping the elevator car when the distance traveled by the elevator car or the time delay exceeds a predefined limit value.

Disclosure of Invention

Objects of the invention

The object of the invention is to disclose a new electronic unintended movement governor, with which it is endeavoured to ensure: in different, changing operating situations and operating environments, the elevator car moves in the elevator shaft only within permitted areas and at permitted speeds. A further object of the invention is to disclose a method with which the aforementioned electronic unintended movement governor is controlled such that it is ensured that the elevator car remains in its permitted operating environment.

Features of the invention

The elevator system and method of the invention in the description part and drawings of the present application discuss inventive embodiments. The inventive content of the application can also be defined differently than in the claims presented below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Features of different embodiments may be applied within the scope of the basic inventive concept together with other embodiments. Furthermore, the features given in connection with the movement limiter according to the invention can be applied in the method according to the invention and vice versa.

The electronic unintended movement governor according to the invention comprises an input for car position data, means for determining the speed of the elevator car, and a number of limit values for the permitted movement of the elevator car, e.g. a limit value for the maximum permitted speed of the elevator car. The unintended movement governor also comprises an overspeed monitor for controlling at least one stopping appliance of the elevator car when the speed of the elevator car exceeds a limit value for the maximum permitted speed. The limit values for permitted elevator car movement include limit values for the distance traveled by the elevator car and the time delay. The electronic unintended movement governor comprises means for determining the distance traveled by the elevator car, and at least two separate controls for controlling the stopping appliance of the elevator car, i.e.: a first controller for immediately controlling a stopping device of the elevator car; and a second controller for controlling the stopping appliance of the elevator car when the distance and/or time delay travelled by the elevator car exceeds a predefined limit value; the control of the stopping device of the elevator car includes the control of the mechanical brake and the disconnection of the power supply circuit of the motor.

An electronic unintended movement governor according to the invention comprises: input for position data of the car and possibly speed data of the car and/or traction sheave; means for determining the speed of the elevator car; means for controlling at least one stopping device of the elevator car; and a plurality of limit values for permitted movement of the elevator car, e.g. a limit value for the maximum permitted speed of the elevator car. According to the invention, it is also possible to integrate into the unintended movement governor a measuring device for measuring the speed and/or position of the elevator car. One unintended movement governor according to the invention comprises an overspeed monitor for controlling at least one stopping appliance of the elevator car when the elevator car exceeds the limit value for the maximum permitted speed. In one embodiment of the invention the limit values for permitted elevator car movement comprise limit values for the distance traveled by the elevator car, and for the time delay. In this embodiment of the invention the electronic unintended movement governor comprises means for determining the distance traveled by the elevator car, a timer, and at least two separate controls for controlling the stopping appliance of the elevator car, namely:

-a first control for immediately controlling at least one stopping appliance of the elevator car; and

-a second controller for controlling at least one stopping appliance of the elevator car when the distance and/or time delay travelled by the elevator car exceeds a predefined limit value.

The aforementioned control may be direction dependent. In this case the electronic unintended movement governor determines the direction of movement of the elevator car on the basis of the speed data or the position data of the elevator car. Now, on the basis of the direction of movement of the elevator car, the control of the stopping appliance of the elevator car is selected such that: the stopping device is controlled by a first control for the stopping device in a first direction of movement of the elevator car and by a second control in a second direction of movement.

In one embodiment of the invention both the limit value for the distance traveled by the elevator car and the time delay are functions of the speed of the elevator car. For example, if the elevator car arrives at the terminal floor at a great speed, it is necessary to activate the stopping function faster than if the speed of the elevator car had decreased when approaching the terminal floor. In this case, the time delay can be shortened. On the other hand, the stopping distance of the elevator car depends on the speed of the elevator car when controlling the machinery brake. In this case this stopping distance can be taken into account so that the limit value for the distance traveled by the elevator car increases as the speed of the elevator car increases and the gripping function does not need to be activated unnecessarily when the machinery brake is working properly.

In one embodiment of the invention, in an elevator system with counterweight, the limit value for permitted elevator car movement comprises a limit for permitted movement of the counterweight in the elevator shaft. The limit values for the permitted counterweight movement can be defined separately for regular and service travel, so that: with service travel, the limit value limits the limit of movement of the counterweight in the elevator shaft to be further from the end of the shaft than the limit value used during regular travel. While preventing the counterweight near the end of the elevator shaft from moving, at the same time a sufficient safety service space in the elevator shaft is ensured. The elevator system according to the invention can also be an elevator system without counterweight, in which case these limit values are not necessarily needed.

The electronic unintended movement governor according to the invention uses the speed data and/or the position data of the elevator car as monitoring information. These data can be measured in a number of different ways. In one embodiment of the invention the position is measured from a magnetic strip placed in the elevator shaft in the direction of travel of the elevator car by using a Hall sensor that reacts to the magnetic field of the magnetic strip. In another embodiment of the invention prior art RFID sensors are placed in the elevator shaft, which RFID sensors specify different position data of the elevator shaft depending on their position, e.g. floor information or end limit information. The position and speed of the elevator car can also be measured with a prior-art absolute encoder located in connection with the elevator car, which encoder gives pulse-shaped or DC voltage information about the position of the elevator car.

In one embodiment of the invention, the overspeed monitoring operates such that: the speed of the elevator car is compared with a limit value for the maximum permitted speed and, if the speed exceeds this limit value, the stopping appliance of the elevator car is controlled using an electronic unintended movement governor. The stopping appliance can be a stopping appliance connected to the guide rails of the elevator car or it can also be a machinery brake connected to the crane, e.g. to the traction sheave of the elevator motor.

Overspeed monitoring may also be multi-staged such that: a first stopping appliance, e.g. a machinery brake, is controlled when the speed of the elevator car exceeds a first limit value for the speed, and a second stopping appliance, e.g. a guide-rail brake or a safety gear to stop the elevator, is controlled when the speed of the elevator car exceeds a second limit value for the speed, the absolute value of which is greater than the absolute value of the first limit value for the speed. For example, the aforementioned limit value for the speed of the elevator car can also vary as a function of the position of the elevator car, so that: the closer to the end of the elevator shaft the limit value has a smaller absolute value. Furthermore, the limit value may vary depending on the desired setting of the speed of the elevator car, so that: the absolute value of the limit value is always greater than the absolute value of the speed reference, according to a predetermined constant or according to a scaling factor greater than 1.

In one embodiment of the invention, the overspeed governor comprises: a first input of a first activation signal with which a first control for immediately controlling a stopping appliance of the elevator car is activated; and a second input of a second activation signal with which a second control for controlling a stopping appliance of the elevator car is activated when the distance and/or time delay traveled by the elevator car exceeds a predefined limit value. The time delay in the unintended movement governor according to the invention can also receive the value 0.

The unintended movement governor according to the invention can also comprise an input for a mode signal of the elevator system, which mode signal comprises at least information about the service driving mode of the elevator system. The input may comprise information also about other modes of the elevator system, e.g. the mode of the elevator system used at construction time or the emergency driving mode.

An unintended movement governor according to the invention comprises an output for a signal indicating speed data of the elevator car and/or position data of the elevator car. This data can be transmitted to the elevator control system.

An unintended movement governor according to the invention can comprise an output for a signal indicating the operational status of the unintended movement governor. The elevator control system can read this signal and it can stop the elevator in a controlled manner under the control of the signal data at the nearest floor or, if the signal data makes it necessary, can drive the elevator car to stop as quickly as possible with a deceleration ramp.

The electronic unintended movement governor according to the invention can comprise a serial interface circuit with which information about the speed and/or position data of the elevator car and possibly information about the operating state of the unintended movement governor can be transmitted as a serial interface signal to the elevator control system.

An unintended movement governor according to the invention may comprise means for controlling the machinery brake and possibly for disconnecting the power input circuit of the motor. The means may comprise a switch connected to the safety circuit of the elevator, the opening of which switch results in the opening of the safety circuit, as a result of which the power input circuit of the motor is opened and the machinery brake is operated. These controls can also be used in the elevator system to report the operating status of unintended movement regulators: when the safety circuit switch controlled by the unintended movement governor is closed, the elevator control system can assume that the unintended movement governor is in an operating condition.

One unintended movement governor according to the invention comprises a non-volatile memory in which at least information about the travel prevention of the elevator is recorded. The memory may be any prior art flash or EEPROM memory, whatever the information in it is retained when power is removed. Additionally, the unintended movement governor may include a power-off safety device to ensure operation of the non-volatile memory. This means that: when the backup battery fails during a power outage, the operating voltage of the unintended movement governor disappears first. When the operating voltage is restored, the unintended movement governor remains in the travel-prevented mode, in which case, for example, a service person must manually investigate by changing the state of a switch associated with the unintended movement governor, thereby releasing the travel-prevented mode. Only after this is the unintended movement governor allowed for movement of the elevator car.

A manually operated switch is associated with an unintended movement governor according to the invention for resetting the travel prevention of the elevator. It is possible to switch the unintended movement governor to the drive prevented mode always when controlling the stopping appliance of the elevator car. In this case, as a result of operating the stopping appliance, the service person must always investigate, reset the drive prevented mode for the elevator and at the same time ensure safe operation of the elevator system.

In one unintended movement governor according to the invention the limit values for the permitted movement in the elevator shaft comprise a first limit value for the limit of movement of the elevator car in the elevator shaft in the service drive mode and a second limit value for the limit of movement of the elevator car in the elevator shaft in the normal drive mode. The first limit value limits the limit of movement of the elevator car in the elevator shaft to be further from the end of the shaft than the second limit value to ensure that in the service drive mode there is sufficient and safe service space in the elevator shaft.

In the unintended movement governor according to the invention the input for car position data can comprise the input of end limit identification data of the elevator shaft.

The limit values for the movement permitted by one unintended movement governor according to the invention comprise limit values for the limits of movement of the elevator car in the elevator shaft during construction-time use. During construction-time use, e.g. when installing guide rails, the elevator must be moved in the elevator shaft. In this case, some guide rails will still be missing and the movement of the elevator car is limited to only a part of the elevator shaft. The safety of the construction-time use is increased when the movement of the elevator car outside the permitted area is also prevented during the construction time by controlling, if necessary, at least one stopping appliance of the elevator car.

Sometimes water accumulates at the bottom of the elevator shaft. If sufficient water accumulates at the bottom of the shaft, there is a risk that the elevator car will collide with a pool of water. If such a hazard exists, a flood sensor may be mounted at the bottom of the hoistway, which detects the accumulated water. On the basis of the sensor data, the movement of the elevator car near the bottom of the shaft can be limited to prevent collisions. In this case, the limit value of the movement allowed by the electronic unintended movement governor may comprise a separate limit value, depending on the contingency (continence) of such a flooding situation.

An unintended movement governor according to the invention comprises the input of two car position data, and possibly two car speed data, which are independent of each other. In this case, the two separately measured speed/position data can be compared with one another in the unintended movement governor, so that the correctness of the measurement can be ensured.

One unintended movement governor according to the invention comprises means for locking the wheel of the mechanical overspeed governor. When locking the wheel of the overspeed governor, the safety gear connected to the overspeed governor via the rope starts braking the movement of the decelerating elevator car. An advantage is gained from this when it is desired to control the mechanical overspeed governor at a speed slower than the preset operating speed of the overspeed governor.

One unintended movement governor according to the invention comprises means for controlling the braking device connected to the guide rail. The aforementioned braking device may be some kind of guide rail brake of the prior art, or a safety gear, or other braking device including electrically assisted control. The control of the power assist means such control that: when activated, operate irreversibly, and removal of control requires manual restoration of the control device.

In a method according to the invention for controlling an electronic unintended movement governor: measuring position data of the elevator car; determining speed data of the elevator car on the basis of the measurement and comparing the speed data with a limit value for the maximum permitted speed; in which case at least one stopping appliance of the elevator car is controlled when the speed exceeds a maximum permitted limit value; when the first controller is activated, controlling the mechanical brake at least immediately and disconnecting the power input circuit of the motor; alternatively, when the second controller is activated, the passage of the time delay is determined, and after the time delay: determining a distance traveled by the elevator car by measuring changes in car position data; and, when the distance of travel exceeds a predefined limit value for the distance, controlling at least the mechanical brake and opening the power input circuit.

In one method according to the invention for controlling an electronic unintended movement governor, elevator car position data and possibly speed data of the elevator car are read, speed data of the elevator car are determined, and the speed data are compared with a limit value for the maximum permitted speed. The speed data can be determined from the position information of the elevator car by means of prior-art methods by measuring the position change as a function of time. When the speed of the elevator car exceeds the limit value for the maximum permitted speed, the stopping appliance of the elevator car is controlled. There may also be a plurality of limit values for the maximum permitted speed and, as a result of exceeding different limit values, different stopping appliances of the elevator car may be controlled. For example, the machinery brake can be controlled when the speed of the elevator car exceeds a first limit value, and the safety gear of the elevator car can be controlled when the speed exceeds a second limit value having an absolute value greater than the absolute value of the first limit value. In one method according to the invention for controlling an electronic unintended movement governor the stopping appliance of the elevator car is controlled immediately when the first control is activated. On the other hand, if the second control is active, when this control is activated, the passage of any time delay is determined with a timer and after a possible time delay the distance traveled by the car is determined by measuring the change in the position data of the elevator car and, when the distance traveled exceeds a predefined limit value for the distance, the stopping appliance of the elevator car is controlled. The aforementioned time delay may also be 0, in which case in this method according to the invention the time delay is not measured at all.

In another method according to the invention, the first and second activation signals are read. A first control for immediately controlling the stopping appliance of the elevator is activated in response to the first activation signal. On the other hand, in accordance with the second activation signal, a second control for controlling the stopping appliance of the elevator car is activated and, in this case, the stopping appliance of the elevator car is controlled when the distance traveled by the elevator car and the possible time delay exceed predefined limit values.

In one method according to the invention information about the position of the elevator car in the elevator shaft is read. At the same time the mode signal of the elevator system is read and on the basis of this signal the mode of the elevator system is deduced. By using the pattern thus read, the stopping appliance of the elevator car is controlled such that: in the service drive mode the position data of the elevator car are compared with the limit of movement in the elevator shaft in the service drive mode and, when it is detected that the elevator car has reached the limit, the stopping appliance of the elevator car is controlled, optionally in accordance with the first control or the second control. On the other hand, in the normal drive mode the position data of the elevator car are compared with the limit of movement in the elevator shaft in the service drive mode and, when it is detected that the elevator car has reached the limit, the stopping appliance of the elevator car is controlled according to the first control. For example, the service travel mode means a mode to which the elevator system is switched for a service procedure. This mode can be switched on, for example, so that the control system of the elevator checks a manually operated service travel switch and, when it detects that the state of the switch has been changed to the position required for the service travel mode, the control system switches or is switched to the service travel mode. For example, a switch to a service drive mode can also take place, so that the control system of the elevator checks the position of the landing door and possibly of the car door and, on the basis of their position, infers that a person has moved into the elevator shaft. For example, the movement of a person into the elevator shaft can take place by manually opening the landing door with a special service key. When the person has moved into the elevator shaft, in which case the elevator system automatically switches to the service drive mode. On the other hand, the normal travel mode means the normal operating state of the elevator, in which case it serves passengers by receiving landing calls and by traveling from one floor to another according to the calls.

In one method according to the invention, the unintended movement governor comprises a non-volatile memory and a manually operated switch. In the method, after controlling the stopping appliance of the elevator car, the next run is prevented by switching to the drive preventing mode of the unintended movement governor and by recording this information in the non-volatile memory of the unintended movement governor. In the method, a manual operation switch is also read, and when the switch position is changed to allow the blocking mode to be cancelled, the travel blocking mode is cancelled. The travel-prohibited mode means a state in which: unintended movement governor endeavors to prevent all movement of the elevator car by controlling some prior-art stopping device of the elevator car, e.g. a safety gear. If the safety gear is adjusted manually, but the drive prevention mode is not cancelled, the electronic unintended movement governor immediately tries again to control the safety gear, thereby trying to prevent movement of the elevator car.

In one method according to the invention, when the unintended movement governor has switched to the drive prevented mode, information about the drive prevented mode is sent as an output signal, which indicates the operating state of the unintended movement governor. On the other hand, when the unintended movement governor has switched to the travel-permitted mode, information about the travel-permitted mode is transmitted as an output signal, which indicates the operating state of the unintended movement governor.

The aforementioned signals processed by the inputs and outputs of the electronic unintended movement governor may be signals formed in parallel or formed by a serial interface. In addition, the signals can also be the switching outputs and switching inputs of the relays, in which case they can be installed in the safety circuit of the elevator. The aforementioned electronic unintended movement governor can be used in certain elevator systems in which no prior-art elevator safety circuit is present, but which have been replaced by a separate electronic safety device. The electronic unintended movement governor can also be one of these electronic safety devices.

Advantages of the invention

The electronic unintended movement governor enables the movement of the elevator car in the elevator shaft to be monitored centrally and limited to permitted areas by using a single safety device. The unintended movement governor can contain different limit values for permitted movement that vary for different operating situations and operating environments, but the movement of the elevator car is stopped in all operating situations always with the same safety-approved control method using safety-approved stopping means, such as safety gears. This improves the safety and reliability of the elevator system. Also, it simplifies the elevator system, since different mechanical safety functions and safety devices can be integrated into one entity. Likewise, the safety of the elevator system can be managed both in the normal drive mode and in the service drive mode, and e.g. during construction-time use or during a water leak.

The electronic unintended movement governor according to the invention can also be arranged as a part of an existing elevator system, e.g. in connection with modernization of the elevator system. The unintended movement governor can be connected to the elevator system in connection with the previously incorporated mechanical overspeed governor, in which case the safety function integrated into the unintended movement governor can be put into use quickly and cost-effectively in modern elevators. Furthermore, in modernization, it is also not necessary in this case to install new mechanical braking devices in the elevator system.

Since the electronic unintended movement governor constantly determines the movement of the elevator car, the stopping function becomes more accurate when compared to prior-art solutions such as the following: in this prior art solution, the mechanical overspeed governor operates separately in relation to the wheel of the overspeed governor and tripping (tripping) takes place, for example, at 90 degree intervals on the wheel of the overspeed governor.

The electronic unintended movement governor according to the invention is easy to connect to the elevator control system and, as defined in the invention, the interface can be very simple, comprising at its simplest only two separate control data (first and second control signals) and one feedback data for the elevator control system about the operating state of the unintended movement governor.

Since the movement of the elevator car near the end of the elevator shaft is monitored and limited by controlling the stopping appliance of the elevator car, it is ensured that the elevator car does not run onto the end buffer in an uncontrolled manner. In this case, the size of the buffer can be made lighter, which saves costs.

Drawings

The invention will be described in more detail below by means of some of its embodiments, with reference to the attached drawings, in which:

fig. 1 shows an elevator system from a first direction, fitted with a safety device according to the invention;

fig. 2 presents an elevator system matching the safety arrangement according to the invention, seen from a second direction;

figure 3 shows the operation of a safety device according to the prior art;

fig. 4 shows an electronic Unintended Movement Governor (UMG) according to the invention.

Detailed Description

Fig. 1 shows an elevator system from a first direction, fitted with an electronic unintended movement governor according to the invention. The elevator car 31 and the counterweight 32 are moved by the elevator motor 42. The motor receives its power supply from a power input circuit 23, which power input circuit 23 comprises a main contactor and a frequency converter for controlling the elevator motor. The elevator car moves in the elevator shaft 41 in a fairly vertical direction. A buffer 39A for the elevator car and a buffer 40A for the counterweight are mounted at the top end 28A of the elevator shaft. Correspondingly, a buffer 39A for the elevator car and a buffer 40B for the counterweight are mounted at the bottom end 28B of the elevator shaft. Through the buffer, an effort is made to attenuate the collision in the event that the elevator car or counterweight travels to the end in an uncontrolled manner. In this embodiment of the invention the electronic unintended movement governor 1 is arranged on the elevator car. In a preferred embodiment of the invention, an unintended movement governor is associated with the power input circuit 23 of the motor and this unintended movement governor can disconnect the power input circuit by opening the main contactor and by preventing control of the IGBT transistors acting as control switches of the frequency converter. Also associated with the unintended movement governor 1A is a manually operated switch 25, which by changing its state can switch the unintended movement governor out of the drive prevented mode.

Fig. 2 presents the elevator system according to fig. 1 seen from a second direction. The elevator can move along the guide rails 33. The elevator system according to the invention comprises two stopping devices of the elevator car: a mechanical brake 14 and a safety gear 15. Furthermore, the elevator system comprises a mechanical overspeed governor 16, which trips the safety gear via the rope in an overspeed situation. The solenoid 35 is associated with the wheel of the mechanical overspeed governor, by means of which the electronic unintended movement governor 1 controls the locking of the wheel of the overspeed governor, in which case the gripping function is activated under the control of the electronic unintended movement governor. Two end limit switches are located near the ends of the elevator shaft, namely one end limit switch 27 for the normal drive mode and the other end limit switch 26 for the service drive mode. The safety service space 29A in the top part and the safety service space 29B in the bottom part of the elevator shaft are limited by means of limit switches for the service drive mode. This occurs so that the electronic unintended movement governor reads the mode of the elevator system from the elevator control system and when it detects that the elevator system has switched to service drive mode, it puts the service drive limit switch 26 into service. When the electronic unintended movement governor detects, via the reader 30 associated with the elevator car, that the elevator car has moved in position to serve the travel limit switch, the unintended movement governor controls the safety gear 15 by locking the wheel of the mechanical overspeed governor 16, the elevator car stops and is locked into its position. The electronic unintended movement governor 1 contains two separate controls for controlling the safety gear. The safety gear can be controlled in accordance with the first control, in which case the gripping is started immediately when the elevator car reaches the service run limit switch, or the safety gear can be controlled after a predetermined delay and, in addition, the elevator car is still allowed to move after that to the extent of a predetermined limit value for the movement of the elevator car. The delay can also be 0, in which case the unintended movement governor immediately starts measuring the distance traveled by the elevator car when it reaches the service travel limit switch, and the gripping is activated when the distance exceeds a predefined limit value. In addition, during the construction time, during which different limit values for the permitted movement are in use in the elevator system in question, the limit values are set by the limits of the permitted movement of the elevator car and counterweight in the elevator shaft. During construction time, the elevator car is often used as an aid to the construction work (e.g. when installing the guide rails 33). In this case it must be possible to safely move the elevator car in a limited area in the elevator shaft (also e.g. in the case of mounting guide rails only in parts of the elevator shaft). Fig. 2 shows a build time scenario by using an example. In which the limit value of the movement permitted by the electronic unintended movement governor limits the limit of the movement of the elevator car below the limit 34. If the elevator car reaches the limit point 34 (above which the installation of the guide rails is in progress), the electronic unintended movement governor controls the safety gear and prevents movement of the elevator car to the safety zone set by the limit values.

Another embodiment of the invention does not comprise separate limit switches 26, 27, but instead the unintended movement governor determines the position of the elevator car in the elevator shaft and compares it with the limit values for permitted movement, which set the limits for the movement of the elevator car in the elevator shaft in the normal drive mode as well as in the service drive mode. The limit value for the service drive mode sets the limit of movement further from the end 28 of the elevator shaft than the limit value for the normal drive mode, in which case a sufficient service space near the end of the elevator shaft can be ensured.

The limit value for the movement of the elevator car permitted by the electronic unintended movement governor can also comprise a limit value for the maximum permitted speed of the elevator car. In this case, the unintended movement governor can monitor the speed of the elevator car, like the prior art overspeed governor.

Fig. 3 shows the operation of a prior art overspeed governor in normal driving mode. The graph 38 represents the set value of the speed of the elevator car, i.e. the speed reference (VREF) as a function of the position (X) of the elevator car in the elevator shaft. The graphs 36 and 37 represent two different limit values for the maximum permitted speed, which vary as a function of the position (X) of the elevator car in the elevator shaft. Before starting, the elevator car is at a floor, at the point of the elevator shaft, X is 0. After starting, the elevator car accelerates to a steady speed according to the speed reference 38 and when the floor is approached, braking of the elevator car is started so that it continues to follow the speed reference. At some point in the elevator shaft, deceleration of the elevator car is started and an effort is made to stop the elevator car on the basis of the speed reference at the floor at which point X ═ X1 in the elevator shaft. If the speed of the elevator car measured during the run past the first limit value 36 of the speed increases, an attempt is made to stop the elevator car by controlling the mechanical brake of the elevator car. The safety gear of the elevator car is also controlled if the speed still continues to increase past the second limit value 37 of the speed.

Fig. 4 shows an electronic unintended movement governor 1 (UMG) according to the invention. The unintended movement governor comprises inputs for position information 2 of the elevator car (car position), speed information 3 of the elevator car (car speed), status signals 19 of the elevator system (elevator status), a first control signal 17 for activating the first control (activation signal 1), and a second control signal 18 for activating the second control (activation signal 2). The output of the electronic unintended movement governor is a position signal and/or a speed signal 20 of the elevator car (car position/speed) and a signal 21 indicating the operating status of the electronic unintended movement governor (UMG status). The unintended movement governor also comprises means 5 for controlling at least one stopping appliance (stopping appliance) of the elevator car, and means 22 for opening the power input circuit (main contactor/IGBT control) of the motor. In this preferred embodiment of the invention, the components 5 and 22 are the contacts of a relay, which are controlled by an overspeed governor. The stopping appliance of the elevator car, which can be a guide-rail brake, can be controlled by means of the component 5. The power supply to the magnetic circuit of the guide-rail brake can be disconnected by means of the contacts of the relay, in which case the braking function is activated. The component 22 comprises contacts with which the coil of the main contactor can be controlled. When the contact is opened, the supply of current to the coil is blocked, and the main contactor is opened. The unintended movement governor also comprises means 4 for determining the speed of the elevator car, and means 9 for determining the distance traveled by the elevator car. The speed of the elevator car can be determined on the basis of the measurement 2 of the elevator car position data with prior-art monitoring of the position change, or it can be measured directly with the measurement 3. In addition, the electronic unintended movement governor includes CONTROL LOGIC (CONTROL LOGIC) and a non-volatile memory 24 (memory). The desired control of the electronic unintended movement governor is activated by using the first control signal 17 or the second control signal 18. A first control for immediately controlling at least one stopping appliance of the elevator car is activated by using the first control signal. In this preferred embodiment of the invention, a prior art safety gear is used as the stop means. By using the second control signal to activate the second control for controlling the stopping appliance of the elevator car, in which case the measurement of any predetermined time delay is started and the determination of the distance traveled by the elevator car is started when the time delay has elapsed. When the distance exceeds a predefined limit value, the elevator car is stopped by controlling the safety gear. The second control can be activated, for example, when the elevator car is stopped at a landing, in which case it can be ensured by this control that: the elevator car cannot leave the landing e.g. when the machinery brake fails, or when the ropes slide on the traction sheave.

It is obvious to the person skilled in the art that the invention is not limited solely to the examples described above, but that it may be varied within the scope of the claims presented below. It is also obvious to the person skilled in the art that the functional parts of the aforementioned unintended movement governor do not necessarily need to be separate, but that they can be integrated directly into the control system of the elevator.

The invention is not limited to the use of examples to describe the above-described embodiments of the invention, but many modifications and different embodiments of the invention are possible within the scope of the inventive concept defined by the appended claims.

Claims (17)

1. An electronic unintended movement governor, comprising:

input for elevator car position data;

means for determining a speed of the elevator car;

a plurality of limit values for permitted movement of the elevator car, including a limit value for a maximum permitted speed of the elevator car;

and the unintended movement governor also comprises an overspeed monitor for controlling at least one stopping appliance of the elevator car when the speed of the elevator car exceeds the limit value for the maximum permitted speed,

wherein the limit values for permitted movement of the elevator car comprise limit values for the distance traveled by the elevator car and for the time delay; and the electronic unintended movement governor further comprises means for determining the distance traveled by the elevator car and at least two separate controls for controlling the stopping appliance of the elevator car, the at least two separate controls comprising:

a first control for immediately controlling at least one stopping appliance of the elevator car, an

A second control for controlling at least one stopping appliance of the elevator car when the distance and/or time delay travelled by the elevator car exceeds a predefined limit value,

and wherein the control of the stopping device of the elevator car comprises: controlling a mechanical brake and disconnecting a power input circuit of the motor;

the limit values for permitted movement further include: limit values for the limits of movement of the elevator car in the elevator shaft during construction-time use.

2. The electronic unintended movement governor of claim 1 wherein the unintended movement governor comprises: a first input for a first activation signal with which to activate the first control for immediately controlling a stopping appliance of an elevator car; and a second input for a second activation signal with which the second controller for controlling the stopping appliance of the elevator car when the distance and/or time delay travelled by the elevator car exceeds a predefined limit value is activated.

3. The electronic unintended movement governor of claim 1 or 2 wherein the unintended movement governor comprises an input for a mode signal of the elevator system, the mode signal comprising at least information about a service driving mode of the elevator system.

4. The electronic unintended movement governor of claim 1 or 2 wherein the unintended movement governor comprises a signal output that indicates elevator car speed data and/or elevator car position data.

5. The electronic unintended movement governor of claim 1 wherein the unintended movement governor includes a signal output that indicates an operational status of the unintended movement governor.

6. The electronic unintended movement governor of claim 1 wherein the unintended movement governor comprises a non-volatile memory for at least recording information about the travel prevention of the elevator.

7. The electronic unintended movement governor of claim 1 further comprising a manually operated switch associated with the unintended movement governor for resetting a drive prevented mode of an elevator.

8. The electronic unintended movement governor of claim 1 wherein the limit values for permitted movement in the elevator hoistway include a first limit value for the limit of movement of the elevator car in the elevator hoistway in the service travel mode and a second limit value for the limit of movement of the elevator car in the elevator hoistway in the normal travel mode; and wherein the first limit value limits the limit of movement of the elevator car in the elevator shaft to be further from the end of the shaft than the second limit value to ensure a service space in the elevator shaft in the service drive mode.

9. The electronic unintended movement governor of claim 1 further comprising an input for car position data that includes: for the input of end limit identification data of the elevator shaft.

10. The electronic unintended movement governor of claim 1 wherein the unintended movement governor comprises an input for two car position data that are independent of each other and/or for two car speed data that are independent of each other.

11. The electronic unintended movement governor of claim 1 wherein the unintended movement governor includes a means for locking the wheel of the mechanical overspeed governor.

12. The electronic unintended movement governor of claim 1 wherein the unintended movement governor includes means for controlling a braking device that is connected to a guide rail.

13. A method for controlling an electronic unintended movement governor, comprising the steps of:

measuring position data of the elevator car and speed data of the elevator car;

comparing the speed data with a limit value for the maximum permitted elevator car speed;

controlling at least one stopping appliance of the elevator car when the measured speed of the elevator car exceeds a maximum permitted limit value of the elevator car;

when a first control for immediately controlling the stopping appliance of the elevator car is activated, at least the elevator car brake is immediately controlled and the power input circuit for the elevator running motor is disconnected, or

Determining the passage of a time delay when activating the second controller, and after the time delay:

determining a distance traveled by an elevator car by measuring a change in the car position data; and

controlling at least the elevator car brake and opening the power input circuit when the distance traveled exceeds a predefined distance limit value,

wherein the limit values for permitted movement include: limit values for the limits of movement of the elevator car in the elevator shaft during construction-time use.

14. The method of claim 13, wherein the method comprises the steps of:

the first activation signal and the second activation signal are read,

activating a first control for immediately controlling at least one stopping appliance of the elevator in dependence on the first activation signal or activating a second control for controlling at least one stopping appliance of the elevator car in dependence on the second activation signal; and

the stopping appliance of the elevator car is controlled when the distance traveled by the elevator car and any time delay exceed predefined limit values.

15. The method of claim 14, wherein the method further comprises the steps of:

reading information about the position of the elevator car in the elevator shaft;

reading a mode signal of the elevator system and deducing the mode of the elevator system on the basis of said signal;

controlling at least one stopping appliance of the elevator car as follows:

in the service drive mode, comparing the position information of the elevator car with the limit of movement of the elevator car in the service drive mode in the elevator shaft, and, when it is detected that the elevator car has reached the limit, controlling at least one stopping appliance of the elevator car according to the first control or the second control;

in the normal drive mode the position information of the elevator car is compared with the limit of movement in the elevator shaft in the normal drive mode and, when it is detected that the elevator car has reached the limit, at least one stopping appliance of the elevator car is controlled according to the first control.

16. The method of claim 14, wherein the method further comprises the steps of:

sending information about the travel prevented mode as an output signal indicating an operational state of the unintended movement governor when the unintended movement governor has switched to the travel prevented mode; and

when the unintended movement governor has been switched to a mode that is travel-enabled, information about the mode that is travel-enabled is sent as an output signal that indicates the operating state of the unintended movement governor.

17. A method for controlling an electronic unintended movement governor, the method comprising the steps of:

measuring position data of the elevator car and speed data of the elevator car;

determining speed data of the elevator car on the basis of the measurement and comparing said speed data with a limit value for the maximum permitted speed of the elevator car;

controlling at least one stopping appliance of the elevator car when the speed data exceeds a maximum permitted limit value;

controlling at least the mechanical brake and disconnecting the power input circuit immediately when the first controller is activated, or determining the lapse of a time delay and, after the time delay, when the second controller is activated: determining a distance traveled by an elevator car by measuring a change in the car position data;

controlling at least the mechanical brake and opening the power input circuit when the distance travelled exceeds a predefined distance limit value;

reading the first activation signal and the second activation signal;

activating a first control for immediately controlling at least one stopping appliance of the elevator in dependence on the first activation signal or activating a second control for controlling at least one stopping appliance of the elevator car in dependence on the second activation signal; and

when the distance traveled by the elevator car, and possibly the time delay, exceeds a predefined limit value, the stopping appliance of the elevator car is controlled,

wherein the method comprises a non-volatile memory and a manually operated switch, and wherein the method further comprises the steps of:

after controlling at least one stopping appliance of the elevator car, stopping the next run by switching to a drive prevention mode of the unintended movement governor and by recording this information in a non-volatile memory of the unintended movement governor; and

the manual operation switch is read, and when the position of the switch is changed to allow the cancellation of the travel prevention mode, the travel prevention mode is cancelled.