Patent Description:
A parking brake solves the problem that is caused by the suspension elasticity during a loading and unloading situation of the elevator car. The parking brake holds the elevator car in its place during loading and unloading and releases its grip after the load has been transferred to the suspension ropes and the car and landing doors have been closed, before the elevator starts to run again. The rope tension should be adjusted to correspond with the changed load at the car so as to avoid an unpleasant jerk when the parking brake is released.

<CIT> discloses a solution for controlling movement of an elevator car, in particular in context of parking of an elevator car immovably at a landing.

There is a need for an elevator parking brake solution that would avoid the unpleasant jerk when the parking brake is released.

According to a first aspect of the present invention, there is provided an elevator parking brake. The parking brake comprises brake pads configured to provide a braking force against a guide rail in a loading and unloading situation of an elevator car, and at least one sensor. The elevator parking brake further comprises a first element comprising the brake pads, the first element comprising a first pivot point; a second element connected to the first element; and a third element connected to the second element via a second pivot point and configured to be attached to a sling. A predetermined amount of movement within the elevator parking brake is allowed in the loading and unloading situation of the elevator car by enabling with the first pivot point the first element to pivot with respect to the guide rail and by enabling with the second pivot point the third element to pivot with respect to the second element. The at least one sensor is arranged between the second element and the third element to detect the movement of the third element with respect to the second element, and wherein the at least one sensor is configured to provide at least one indication associated with the movement within the elevator parking brake in the loading and unloading situation of the elevator car.

According to a second aspect of the present invention, there is provided an elevator parking brake. The parking brake comprises brake pads configured to provide a braking force against a guide rail in a loading and unloading situation of an elevator car, and at least one sensor. The elevator parking brake further comprises a fourth element comprising the brake pads, the fourth element comprising a third pivot point enabling the fourth element to pivot with respect to the guide rail; a fifth element connected to the fourth element via a fourth pivot point and configured to be attached to a sling; a connecting element connected to the fourth element via a fifth pivot point; and an attachment member configured to be connected to the sling or the elevator car. A predetermined amount of movement within the elevator parking brake is allowed by the connecting element with respect to the attachment member in the loading and unloading situation of the elevator car, and the at least one sensor is arranged between the connecting element and the attachment member to detect the movement of the connecting element with respect to the attachment member and wherein the at least one sensor is configured to provide at least one indication associated with the movement in the loading and unloading situation of the elevator car.

According to a third aspect of the present invention, there is provided an elevator parking brake. The parking brake comprises brake pads configured to provide a braking force against a guide rail in a loading and unloading situation of an elevator car, and at least one sensor. The elevator parking brake further comprises a first element comprising the brake pads, and a second element connected to the first element with a connection arrangement and configured to be attached to a sling. A predetermined amount of vertical movement within the elevator parking brake is allowed in the loading situation of the elevator car by enabling the second element to vertically move away from the first element and in the unloading situation of the elevator car by enabling the second element to vertically move towards the first element. The at least one sensor is arranged between the first element and the second element to detect movement of the first element with respect to the second element. The at least one sensor is configured to provide at least one indication associated with the movement within the elevator parking brake in the loading and unloading situation of the elevator car.

In an example embodiment, the elevator parking brake comprises a controller operatively connected to the at least one sensor.

In an example embodiment, the at least one sensor is configured to provide the at least one indication when the predetermined amount of movement has been reached. In an example embodiment, the at least one sensor comprises at least one of a switch, a micro switch, a pressure sensor, an optical sensor, a strain gauge, an acceleration sensor or a proximity sensor.

According to a fourth aspect of the present invention, there is provided an elevator car comprising at least one elevator parking brake of the first, second or third aspect.

According to a fifth aspect of the present invention, there is provided a method for operating an elevator system. The method comprises controlling at least one elevator parking brake of the first, second or third aspect associated with the elevator car to provide a braking force against a guide rail in a loading and/or unloading situation of an elevator car; during the loading and/or unloading situation, monitoring a state of the at least one sensor of the at least one elevator parking brake based on the at least one indication provided by the at least one sensor; analyzing the state; and controlling tension of suspension means associated with the elevator car based on the analysis.

In an embodiment, monitoring a state of the at least one sensor comprises monitoring a first indication from the at least one elevator parking brake, the first indication indicating that a predetermined amount of movement within the elevator parking brake has been reached during the unloading situation; and controlling tension of suspension means comprises loosening the suspension means until failing to subsequently detect the first indication from the at least one elevator parking brake.

In an example embodiment, monitoring a state of the at least one sensor comprises monitoring a second indication from the at least one elevator parking brake, the second indication indicating that the predetermined amount of movement within the elevator parking brake has been reached during the loading situation; and controlling tension of suspension means comprises tightening the suspension means until failing to subsequently detect the second indication from the at least one elevator parking brake.

In an example embodiment, the controlling comprises adjusting tension of the suspension means associated with the elevator car to alter a vibration amplitude and/or a frequency of the suspension means based on the analysis.

In an example embodiment, the at least one sensor comprises a single sensor, and the method further comprises failing to detect a change in the state of the sensor in the unloading situation; loosening the tension of the suspension means until detecting a change in the state of the sensor; and tightening the tension of the suspension means until detecting a subsequent change in the state of the sensor.

In an example embodiment, the at least one sensor comprises a single sensor, and the method further comprises failing to detect a change in the state of the sensor in the loading situation; tightening the tension of the suspension means until detecting a change in the state of the sensor; and loosening the tension of the suspension means until detecting a subsequent change in the state of the sensor.

According to a sixth aspect of the present invention, there is provided an elevator system comprising an elevator car; at least one elevator parking brake of the first, second or third aspect associated with the elevator car; suspension means configured to support the elevator car in an elevator shaft; and a controller configured to perform the method for operating an elevator system according to the fifth aspect.

According to various embodiments, an elevator parking brake is disclosed. The elevator parking brake comprises brake pads configured to provide a braking force against a guide rail in a loading and unloading situation of an elevator car, and at least one sensor. The elevator parking brake is configured to allow a predetermined amount of movement within the elevator parking brake in the loading and unloading situation of the elevator car; and the at least one sensor is configured to provide at least one indication associated with the movement within the elevator parking brake in the loading and unloading situation of the elevator car.

<FIG> illustrates an elevator parking brake <NUM> according to an example embodiment. The elevator parking brake <NUM> holds an elevator car in its place during loading and unloading and releases its grip after the load has been transferred to suspension means - suspension ropes for example - and car and landing doors have been closed, before the elevator car starts to run again.

The elevator parking brake <NUM> comprises brake pads <NUM> configured to provide a braking force against a guide rail <NUM> in a loading and unloading situation of an elevator car. Although <FIG> illustrates only one brake pad, the elevator parking brake may include more than one brake pad. The elevator parking brake <NUM> is configured to allow a predetermined amount of movement within the elevator parking brake <NUM> in the loading and unloading situation of the elevator car. The movement may be enabled using elements <NUM>, <NUM>, <NUM> and pivot points <NUM>, <NUM>.

The elevator parking brake <NUM> comprises a first element <NUM> comprising the brake pads <NUM>. The first element <NUM> comprises a first pivot point <NUM> enabling the first element <NUM> to pivot with respect to the guide rail <NUM>. A second element <NUM> is connected to the first element <NUM> with, for example, a bolt or a pin. A third element <NUM> is connected to the second element <NUM> via a second pivot point <NUM>. The third element <NUM> is configured to be attached to a sling <NUM>. The second pivot point <NUM> enables the third element <NUM> to pivot with respect to the second element <NUM> in the loading and unloading situation of the elevator car. When the load of the elevator car increases (i.e. passengers step into the elevator car), the third element <NUM> pivots with respect to the second pivot point <NUM> in a counter-clockwise direction. Similarly, when the load of the elevator car decreases (i.e. passengers step out of the elevator car), the third element <NUM> pivots with respect to the second pivot point <NUM> in a clockwise direction. As the shape of the third element <NUM> is such that it enables a space to be formed between the second element <NUM> and the third element <NUM> at each side of the second pivot point <NUM>, when the third element <NUM> rotates with respect to the second element <NUM>, the distance or angle between the third element <NUM> and the second element <NUM> changes.

At least one sensor <NUM> is arranged between the second element <NUM> and the third element <NUM> to detect movement of the third element <NUM> with respect to the second element <NUM>. In an example embodiment, only one sensor <NUM> is arranged between the second element <NUM> and the third element <NUM>. In another example embodiment, separate sensors <NUM> may be arranged at each side of the second pivot point <NUM>. The sensor <NUM> is configured to provide at least one indication associated with the movement in the loading and unloading situation of the elevator car. In an example embodiment, the at least one indication may be provided when the predetermined amount of movement, for example, <NUM> - <NUM> has been reached. In another example embodiment, the at least one indication may reflect the amount of movement. The indication may comprise a state signal, being for example <NUM> or <NUM> (binary signal), or the indication may comprise a numerical value reflecting the amount of movement. Further, providing an indication is to be understood broadly and it may also refer to an embodiment where the sensor does not send any signals, i.e. absence of signals from the sensor. Thus, absence of a signal from the sensor may also be understood as an "indication". Further, in an example embodiment, the sensor <NUM> is a switch, a micro switch, a pressure sensor, an optical sensor, a strain gauge, an acceleration sensor or a proximity sensor (optical or magnetic). In case an acceleration sensor is used, based on the values provided by the acceleration sensor, it may be determined whether the elevator car is suspending by the suspension means or whether the predetermined amount of movement within the elevator parking brake <NUM> has been reached.

Further, in an example embodiment, load springs 110A, 110B may be arranged between the second element <NUM> and the third element <NUM>, as illustrated in <FIG>. The load springs 110A, 110B may be configured to center the elevator parking brake <NUM>. When the parking brake is in a released state, the load springs 110A, 110B position the second element <NUM> with respect to the pivot point <NUM>.

In an example embodiment, the elevator parking brake <NUM> may comprise a controller operatively connected to the at least one sensor <NUM>.

As a summary of the solution illustrated in <FIG>, the solution is based on the torque in the elevator parking brake <NUM> due the distance <NUM> between the two pivot points <NUM> and <NUM> and the vertical force exerted to the elevator parking brake <NUM>. The illustrated solution avoids the unpleasant jerk when the elevator parking brake is released as the tension of the suspension means has been matched with the changed load in the elevator car.

<FIG> illustrates an elevator parking brake <NUM> according to another example embodiment. The elevator parking brake <NUM> holds the elevator car in its place during loading and unloading and releases its grip after the load has been transferred to suspension means - suspension ropes for example - and car and landing doors have been closed, before the elevator car starts to run again.

The elevator parking brake <NUM> comprises brake pads <NUM> configured to provide a braking force against a guide rail <NUM> in a loading and unloading situation of the elevator car. Although <FIG> illustrates only one brake pad, the elevator parking brake may include more than one brake pad. The elevator parking brake <NUM> is configured to allow a predetermined amount of movement within the elevator parking brake <NUM> in the loading and unloading situation of the elevator car. The movement may be enabled using elements <NUM>, <NUM>, <NUM> and pivot points <NUM>, <NUM>, <NUM>.

The elevator parking brake <NUM> comprises a fourth element <NUM> comprising the brake pads <NUM>. The fourth element <NUM> comprises a third pivot point <NUM> enabling the fourth element <NUM> to pivot with respect to the guide rail <NUM>. The elevator parking brake <NUM> further comprises a fifth element <NUM> connected to the fourth element <NUM> via a fourth pivot point <NUM> and configured to be attached to a sling <NUM>. The elevator parking brake <NUM> further comprises a connecting element <NUM> connected to the fourth element <NUM> via a fifth pivot point <NUM>. The elevator parking brake <NUM> may be connected to the sling <NUM> or to the elevator car with an attachment member <NUM>.

Further, the at least one sensor <NUM> is arranged between the connecting element <NUM> and the attachment member <NUM> to detect movement of the connecting element <NUM> with respect to the attachment member <NUM>. Depending on the direction of rotation of the fourth element <NUM>, the connecting element <NUM> moves either to the right (the load decreases in the elevator car) or to the left (the load increases in the elevator car). In an example embodiment, a centering spring <NUM> may arranged between the attachment member <NUM> and the connecting element <NUM>. The centering spring <NUM> may be configured to center the mechanical parts when the elevator parking brake <NUM> is in a released state. In another example embodiment, the connecting element <NUM> itself may allow compression and decompression and the at least one sensor <NUM> arranged between the attachment member <NUM> and the connecting element <NUM> is configured to detect movement of the connecting element <NUM> with respect to the attachment member <NUM>. At some point during the compression or decompression, the distance between the connecting element <NUM> and the attachment member <NUM> has changed enough to trigger the indication with the at last one sensor <NUM>. In an example embodiment, the at least one indication may be provided when the predetermined amount of movement has been reached. In another example embodiment, the at least one indication may reflect the amount of movement. The indication may comprise a state signal, being for example <NUM> or <NUM> (binary signal), or the indication may comprise a numerical value reflecting the amount of movement. Further, providing an indication is to be understood broadly and it may also refer to an embodiment where the sensor does not send any signals, i.e. absence of signals from the sensor. Thus, absence of a signal from the sensor may also be understood as an "indication". Further, in an example embodiment, the sensor <NUM> is a switch, a micro switch, a pressure sensor, an optical sensor, a strain gauge, an acceleration sensor or a proximity sensor (optical or magnetic). In case an acceleration sensor is used, based on the values provided by the acceleration sensor, it may be determined whether the elevator car is suspending by the suspension means or whether the predetermined amount of movement within the elevator parking brake <NUM> has been reached.

In an example embodiment, the elevator parking brake <NUM> may comprise a controller operatively connected to the at least one sensor.

As a summary of the solution illustrated in <FIG>, the solution is based on the torque in the elevator parking brake <NUM> due the distance between the brake pad <NUM> gripping point and the sling fixing point when the elevator parking brake <NUM> is applied and the load inside the elevator car is changing. The illustrated solution avoids the unpleasant jerk when the elevator parking brake is released as the tension of the suspension means has been matched with the changed load in the elevator car.

The elevator parking brake <NUM> comprises brake pads <NUM> configured to provide a braking force against a guide rail <NUM> in a loading and unloading situation of an elevator car. Although <FIG> illustrates only one brake pad, the elevator parking brake may include more than one brake pad. The elevator parking brake <NUM> is configured to allow a predetermined amount of movement within the elevator parking brake <NUM> in the loading and unloading situation of the elevator car. The movement may be enabled using elements <NUM> and <NUM>.

The elevator parking brake <NUM> comprises a first element <NUM> comprising the brake pads <NUM>. A second element <NUM> is connected to the first element <NUM> with a connection arrangement, for example, a bolt or a pin. The second element <NUM> is further configured to be attached to a sling <NUM>.

When the load of the elevator car increases (i.e. passengers step into the elevator car), the connection arrangement between the first element <NUM> and the second element <NUM> enables the second element <NUM> to move vertically away from the first element <NUM>. Similarly, when the load of the elevator car decreases (i.e. passengers step out of the elevator car), the connection arrangement between the first element <NUM> and the second element <NUM> enables the second element <NUM> to move vertically towards the first element <NUM>.

At least one sensor <NUM> is arranged between the first element <NUM> and the second element <NUM> to detect movement of the first element <NUM> with respect to the second element <NUM>. In an example embodiment, one sensor may be configured to detect movement in the up direction and another sensor may be configured to detect movement in the down direction. In another example embodiment, only a single sensor may be used to detect movement in the up direction or the down direction. The sensor <NUM> is configured to provide at least one indication associated with the movement of the second element <NUM> with respect to the first element <NUM> in the loading and unloading situation of the elevator car. In an example embodiment, the at least one indication may be provided when the predetermined amount of movement, for example, <NUM> - <NUM> has been reached. In another example embodiment, the at least one indication may reflect the amount of movement. The indication may comprise a state signal, being for example <NUM> or <NUM> (binary signal), or the indication may comprise a numerical value reflecting the amount of movement. Further, providing an indication is to be understood broadly and it may also refer to an embodiment where the sensor does not send any signals, i.e. absence of signals from the sensor. Thus, absence of a signal from the sensor may also be understood as an "indication". Further, in an example embodiment, the sensor <NUM> is a switch, a micro switch, a pressure sensor, an optical sensor, a strain gauge, an acceleration sensor or a proximity sensor (optical or magnetic). In case an acceleration sensor is used, based on the values provided by the acceleration sensor, it may be determined whether the elevator car is suspending by the suspension means or whether the predetermined amount of movement within the elevator parking brake <NUM> has been reached.

As a summary of the solution illustrated in <FIG>, the elevator parking brake <NUM> may be configured to allow a predetermined amount of vertical movement within the brake housing or bracket in the loading and unloading situation of the elevator car, and at least one sensor <NUM> may be arranged to detect the vertical movement.

<FIG> illustrates a controller <NUM> for operating an elevator system according to an example embodiment. <FIG> is discussed together with <FIG> that illustrates a method for operating an elevator system according to an example embodiment and <FIG> that illustrates the elevator system according to an example embodiment.

The method comprises controlling <NUM> at least one elevator parking brake <NUM>, <NUM> associated with an elevator car <NUM> to provide a braking force against a guide rail in a loading and/or unloading situation of an elevator car <NUM>.

At <NUM>, during the loading and/or unloading situation, the controller <NUM> is configured to monitor a state of the at least one sensor of the at least one elevator parking brake <NUM>, <NUM> based on the at least one indication provided by the at least one sensor. Further, providing an indication is to be understood broadly and it may also refer to an embodiment where the sensor does not send any signals, i.e. absence of signals from the sensor. Thus, absence of a signal from the sensor may also be understood as an "indication".

At <NUM>, the controller <NUM> is configured to analyze the state.

At <NUM>, the controller <NUM> is configured to control tension of suspension means associated with the elevator car <NUM> based on the analysis.

In an example embodiment, the controller <NUM> is configured to monitor at step <NUM> an indication from the at least one elevator parking brake <NUM>, <NUM>. The indication may indicate that a predetermined amount of movement within the elevator parking brake <NUM>, <NUM> has been reached during an unloading situation. The controller <NUM> then is configured to control the tension of the suspension means <NUM> to change until the indication from the at least one elevator parking brake <NUM>, <NUM> changes to indicate that the load of the elevator car corresponds to the tension of the suspension means.

In another example embodiment, the controller <NUM> is configured to monitor at step <NUM> an indication from the at least one elevator parking brake <NUM>, <NUM>. The indication may indicate that a predetermined amount of movement within the elevator parking brake <NUM>, <NUM> has been reached during a loading situation. The controller <NUM> then is configured to control tension of the suspension means <NUM> to tighten the suspension means <NUM> until failing to subsequently receive the indication from the at least one elevator parking brake <NUM>, <NUM>.

In another example embodiment, one sensor is used to indicate with its state equilibrium between the elevator parking brake <NUM>, <NUM> and the tension provided with the suspension means <NUM>. The controller <NUM> may be configured to monitor at step <NUM> the state of the indication from the sensor. When using only one sensor, the sensor may, for example, only detect that the load in the elevator car is greater than the tension of the suspension means <NUM>. When the load in the elevator car is less than the tension of the suspension means <NUM>, the sensor may not provide any indication to the controller <NUM>. This means that the state of the sensor does not change when the load in the elevator car reduces (i.e. in an unloading situation). The controller <NUM> may be configured to loosen the tension of the suspension means <NUM> with an amount that causes a change in the state of the sensor. When the state changes, it means that, due to the reduced tension from the suspension means <NUM>, the elevator parking brake <NUM>, <NUM> now carries some of the load of the elevator car. In response to detecting the state change of the sensor, the controller <NUM> may be configured to tighten the tension of the suspension means <NUM> with an amount that cause the state of the indication of the sensor to change again, i.e. to the state when no indication is received from the sensor. This means that the suspension means <NUM> again completely suspends the weight of the elevator car.

In another example embodiment, one sensor is used to indicate with its state equilibrium between the elevator parking brake <NUM>, <NUM> and the tension provided with the suspension means <NUM>. The controller <NUM> may be configured to monitor at step <NUM> the state of the indication from the sensor. When using only one sensor, the sensor may, for example, only detect that the load in the elevator car is less than the tension of the suspension means <NUM>. When the load in the elevator car is greater than the tension of the suspension means <NUM>, the sensor may not provide any indication to the controller <NUM>. This means that the state of the sensor does not change when the load in the elevator car increases (i.e. in a loading situation). The controller <NUM> may be configured to tighten the tension of the suspension means <NUM> with an amount that causes a change in the state of the sensor. When the state changes, it means that the increased tension of the suspension means <NUM> now corresponds to a load that is greater than that of the elevator car. In response to detecting the state change of the sensor, the controller <NUM> may be configured to loosen the tension of the suspension means <NUM> with an amount that causes the state of the indication of the sensor to change again, i.e. to the state when no indication is received from the sensor. This means that the suspension means <NUM> again completely suspend the weight of the elevator car.

In another example embodiment, the controller <NUM> may be configured to adjust the tension of the suspension means <NUM> to alter a vibration amplitude and/or a frequency of sway in the suspension means <NUM> based on the analysis. The suspension means <NUM> associated with the elevator car <NUM> can be considered as freely vibrating "strings". These strings are excited into vibration, for example, by the movements of the elevator car <NUM> while loading/unloading and during traveling, building sway, accelerations caused by the motor. The swaying problem of the suspension means increases when the maximum travel distance of the elevator increases as it increases the length of the vibrating elements. In the worst case, the sway can have so high amplitude that the suspension means <NUM> touch walls of an elevator shaft or components fixed to the elevator shaft walls. During the sway, for example, metallic round ropes may also bang against each other, thus creating noise and causing minor additional wear. As elevator car moves up in the elevator shaft, the length of the suspension means from the elevator car to a motor decreases. The decreased suspension means length increases the rope swaying frequency and the vibrational energy stored in the suspension means can also increase due to the elevator car and building movement, i.e. energy is transferred from building movement to suspension means movement. By a dynamic adjustment of the tension in the suspension means <NUM>, the vibration amplitude and/or frequency of the swaying suspension means <NUM> can be altered. This allows to get out of the resonance frequency of the suspension means <NUM> and thus effectively preventing the excessive suspension means sway build up during loading/unloading of the elevator car <NUM>.

With the at least one elevator parking brake <NUM>, <NUM> engaged, the sway of the suspension means <NUM> can be detected as the dynamic rope tension changes the same way as the change in the car load, i.e. the movement within the parking brake mechanism as described in the above.

Further, the controller <NUM> may also be configured to modify the tension of the suspension means <NUM> actively. Based on sway detection information, the controller <NUM> may be configured to actively adjust the tension of the suspension means <NUM>. For example, when the tension at the suspension means <NUM> peaks, i.e. they are at the furthest away from their normal (straight) position, the tension is reduced, and when suspension means <NUM> have swayed into the normal (straight) position and are about to continue to the opposite side, the tension may be tightened.

While there have been shown and described and pointed out fundamental novel features as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices and methods described may be made by those skilled in the art without departing from the scope of the claims. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiments may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.

Claim 1:
An elevator parking brake (<NUM>) comprising:
brake pads (<NUM>) configured to provide a braking force against a guide rail (<NUM>) in a loading and unloading situation of an elevator car (<NUM>); and
at least one sensor (<NUM>);
characterized in that the elevator parking brake (<NUM>) further comprises:
a first element (<NUM>) comprising the brake pads (<NUM>), the first element (<NUM>) comprising a first pivot point (<NUM>);
a second element (<NUM>) connected to the first element (<NUM>);
a third element (<NUM>) connected to the second element (<NUM>) via a second pivot point (<NUM>) and configured to be attached to a sling (<NUM>);
wherein a predetermined amount of movement within the elevator parking brake (<NUM>) is allowed in the loading and unloading situation of the elevator car (<NUM>) by enabling with the first pivot point (<NUM>) the first element (<NUM>) to pivot with respect to the guide rail (<NUM>) and by enabling with the second pivot point (<NUM>) the third element (<NUM>) to pivot with respect to the second element (<NUM>); and
wherein the at least one sensor (<NUM>) is arranged between the second element (<NUM>) and the third element (<NUM>) to detect the movement of the third element (<NUM>) with respect to the second element (<NUM>); and
wherein the at least one sensor (<NUM>) is configured to provide at least one indication associated with the movement within the elevator parking brake (<NUM>) in the loading and unloading situation of the elevator car (<NUM>).