CN117043094A

CN117043094A - System for controlling elevator car doors and method of retrofitting elevator car doors

Info

Publication number: CN117043094A
Application number: CN202280023450.5A
Authority: CN
Inventors: 阿苏尔·K; 普拉萨德·萨普卡尔; 迪帕克·瓦尼; 拉胡尔·马哈穆尼
Original assignee: Inventio AG
Current assignee: Inventio AG
Priority date: 2021-03-22
Filing date: 2022-03-15
Publication date: 2023-11-10
Also published as: WO2022200111A1

Abstract

A system for controlling elevator car doors having elevator car door panels moving along a beam, the elevator car door panels being operatively coupled to a motor belt (114, 206, 316) movable over motor pulleys (116, 208, 318) to open and close the elevator car doors, the system comprising: a linear drive member (102, 302) disposed on the cross beam, housing a plunger (104, 304) connected to one end of the elongate member (106, 310); a counterweight (306) placed on the linear drive member (302) via a movable device (308) capable of applying a force to the plunger (304) such that the plunger (304) protrudes from the linear drive member (302); or a spring (108) capable of exerting a force on the plunger (104) such that the plunger (104) protrudes from the linear drive member (102); a lever arm (110, 202, 312) having a first end (110 a, 202a, 312 a) that pivots relative to the free end of the elongate member (106, 310) and a second end (110 b, 202b, 312 b) that pivots rotatably such that the second end (110 b, 202b, 312 b) of the lever arm (110, 202, 312) is located at a predetermined distance from the motor pulley (116, 208, 318) and the lever arm (110, 202, 312) is further connected to a brake pad (112, 204, 314), wherein a braking force is applied to the first end (110 a, 202a, 312 a) of the lever arm (110, 202, 312) through the free end of the elongate member (106, 310) due to a force applied to the plunger (304, 104) by the counterweight (306) or by the spring (108) and such that the lever arm (110, 202, 312) moves such that the predetermined distance is overcome and the lever arm applies an amplified braking force at the brake pad (112, 204, 314), wherein the braking force is applied to the elevator car door (114, 316) to move.

Description

System for controlling elevator car doors and method of retrofitting elevator car doors

Technical Field

The present invention relates to the field of elevators, and in particular to a system for controlling elevator car doors. Furthermore, the invention relates to a method for retrofitting an elevator car door.

Background

Elevators are very common means of transportation from one floor to another floor of a building for people in multi-floor apartments, business complexes, hospitals, shops, restaurants, etc. In conventional elevator systems, a door operating system driven by a linear induction motor is used. A door operating system driven by a linear induction motor and including a movable motor belt controls the opening and closing of the door during normal operation. However, when the elevator is at a floor and the elevator is being shut down or being opened or fully opened, there may be situations where the power supply may be shut down or the door operating system may fail. In this case, the elevator car door may close at an uncontrolled speed and collide with the jamb. In this case this is especially detrimental for passengers who may attempt to climb on or leave the elevator, as this may lead to serious injuries. Furthermore, closing elevator car doors at uncontrolled speeds may also damage the door operating system driven by the linear induction motor.

Elevator car door braking systems are known that overcome the inertia of the door movement and allow the door to close smoothly. Such systems typically employ spring-type electromagnetic brakes that apply friction to the movable motor belt through various means, such as brake shoes. However, such systems have certain limitations. For example, since frictional force that suppresses movement of the elevator car door is directly exerted on the motor belt, this may cause wear of the motor belt due to contact of the brake shoes with the motor belt. Further, since the force required to suppress the movement of the elevator car door is relatively large, the electromagnet must be large enough to be able to generate such braking force.

In JPH09242418A there is provided a method for an elevator car door braking system in which a spring-type electromagnetic brake is provided in a double wing automatic door apparatus for an elevator car. When the power of the door driving motor is cut off, the electromagnet in the spring type electromagnetic brake is released, and the brake shoe is pressed against the doorway frame by the force of the spring, and the door moved by the weight is braked by friction.

Another alternative is provided in EP0841284A1, wherein the elevator car door is driven by a linear motor and the movement of the elevator car door is synchronized with a cable extending over a first sheave and a second sheave with a corrugated bushing. A brake system is positioned adjacent the first pulley and includes a brake shoe attached to a solenoid. The solenoid includes a solenoid coil frame and a plunger having one end inserted into the solenoid coil frame and the other end fixedly attached to the brake shoe. The plunger has a spring mounted thereon, wherein one end of the spring is pressed against the brake shoe and the other end of the spring is pressed against the solenoid coil frame. During a power failure or during a failure of the door operation control system, the solenoid becomes inactive. In the inactive mode, the solenoid coil frame releases the plunger. When the plunger is released, the spring expands and forces the brake shoe forward against the pulley bushing. The undulating surface of the brake shoe engages the undulating pulley bushing and slows the rotation of the pulley. As the rotation of the sheaves slows, the ropes are slowed down as well, thereby slowing the movement of the elevator car door.

However, in both methods, the braking/friction force is applied directly on the sheave contact surface of the motor belt that moves around the sheave. This can therefore lead to uneven wear of the motor belt due to contact of the brake shoes with the motor belt. Furthermore, the required solenoids or electromagnets are large enough to be able to exert a braking force on the motor belt, thereby slowing down the movement of the elevator car door.

Accordingly, there is a need for a system with improved functionality that is capable of applying sufficient braking force with a smaller linear drive member. Furthermore, there is a need for a system that can be combined with existing elevator car doors in a manner that incorporates minimal hardware.

Disclosure of Invention

This need may be met by the subject matter of the independent claims. Advantageous embodiments are defined in the dependent claims and in the following description.

According to a first aspect of the present invention, a system for controlling elevator car doors is disclosed having an elevator car door panel moving along a beam, the elevator car door panel being operatively coupled to a motor belt movable on a motor pulley to open and close the elevator car doors. The system includes a linear drive member disposed on the elevator beam that receives a plunger connected to one end of an elongated member. The system further includes a counterweight placed on the linear drive member via a movable device capable of exerting a force on the plunger such that the plunger protrudes from the linear drive member. Optionally, the system may further comprise a spring capable of exerting a force on the first end of the plunger such that the plunger protrudes from the linear drive member. The system also includes a lever arm having a first end that pivots relative to the free end of the elongated member and a second end that pivots rotatably such that the second end of the lever arm is located a predetermined distance from the motor pulley. The lever arm is also connected to the brake pad. Furthermore, according to a first aspect of the invention, due to the force exerted by the counterweight or spring on the plunger, a braking force is applied to the first end of the lever arm through the free end of the elongated member and the lever arm moves such that a predetermined distance is overcome and the lever arm applies an amplified braking force at the brake pad, said braking force being used to brake the motor belt to brake the movement of the elevator car door.

According to a second aspect of the present invention, a method of retrofitting an elevator car door having an elevator car door panel moving along a beam is disclosed, the elevator car door panel being operatively coupled to a motor belt movable on a motor pulley to open and close the elevator car door. The method comprises providing a system as described in the first aspect of the invention such that the lever arm is positioned in such a way that the second end of the lever arm is rotatably pivoted at a predetermined distance from the motor pulley. The lever arm is also connected to the brake pad and applies an amplified braking force at the brake pad such that the braking force is used to brake the motor belt to brake the movement of the elevator car door.

According to a third aspect of the present invention, a method of safely closing an elevator car door is disclosed. The elevator car door comprises a system according to the first aspect of the invention. The method includes removing power from the linear drive member in the event of a power drop such that the lever arm applies amplified braking at the brake pad such that the braking force is used to brake the motor belt, thereby braking movement of the elevator car door.

The basic idea of an embodiment of the invention can be interpreted as based on the following observations and insights, among other things.

The system presented herein can be installed in a new elevator or can be installed in a conventional elevator with minimal hardware involved. Conventional elevator car doors include an elevator car door panel that moves along a beam that is operatively coupled to a motor belt that is movable over a motor pulley to open and close the elevator car door. The motor belt may be a V-belt or a toothed belt made of different materials, such as leather and reinforced rubber. The motor belt may have a planar contact surface, or may have a contact surface of a particular shape, such as tooth and rib. The motor pulley may be made of cast iron or mild steel or other suitable material. The motor pulley or a second pulley not driven by the motor may include a dedicated surface in contact with the brake pad for braking or alignment of the brake pad.

The lever arm allows the force applied at the end of the elongate member connected to the plunger to be amplified using the lever effect. Thus, the small force of the linear drive member may press the brake pad sufficiently strongly to generate the required braking force or disengage the brake pad.

In an advantageous embodiment of the system, the linear drive member comprises at least one of a solenoid or a pneumatic piston.

If the linear drive member is a solenoid, the linear drive member further comprises a coil former. The linear drive member receives a plunger having a first end and a second end. The second end of the plunger is also connected to one end of the elongate member.

In an advantageous embodiment of the system, the linear drive member is configured to perform at least one of: when the electric power to the linear driving member fails, a braking force is applied through the brake pad, and when the electric power is effective, the braking force applied to the brake pad is removed.

When the power is active, the plunger remains retracted within the linear drive member. When power fails, or when a conventional elevator door operating system fails, the plunger is released from the linear drive member, thereby exerting a force on a first end of a lever arm connected at a free end of an elongated member connected at one end to the plunger.

In an advantageous embodiment of the system, the lever arm is positioned relative to the motor pulley in such a way that the axis of rotation of the lever arm is parallel to the axis of rotation of the motor pulley.

This allows the lever arm to be used as a force amplifier such that the braking force applied on the first end of the lever arm is amplified when transferred to the second end of the lever arm. In an advantageous embodiment of the system, the brake pad is positioned closer to the second end of the lever arm than to the first end of the lever arm.

The positioning of the brake pad closer to the second end of the lever arm allows the amplified braking force to be applied to the motor belt by the brake pad. However, in another embodiment, the brake pad may also be placed at a different location between the first and second ends of the lever arm.

In an advantageous embodiment of the system, the brake pad is movable such that the motor belt is pressed between the brake pad and the motor pulley to generate a braking force.

When the electricity to the elevator is active, the brake pads are not in contact with the motor belt. However, when power to the elevator fails, the brake pad moves toward the motor belt due to the amplified braking force applied by the second end of the lever arm such that the motor belt becomes compressed between the motor pulley and the brake pad to brake movement of the elevator car door.

In an advantageous embodiment of the system, the brake pad comprises a friction material bonded to its surface.

In one embodiment, the friction material includes at least one of rubber, ethylene Propylene Diene Monomer (EPDM), or a polymer-based compound. Such friction material may be bonded to the surface of the brake pad with an adhesive, which allows for repeated removal and reattachment of the friction material on the brake pad, thereby simplifying maintenance.

In an advantageous embodiment of the system, the system further comprises an extension spring arranged on the cross beam and configured to prevent deformation of the lever arm.

This also allows the use of very strong linear drive members that transmit more force than is required to lift the lever against the spring or counterweight. The excess force is then compensated for by the tension spring. The extension spring thus acts as a limiter of the upward movement of the lever.

In an advantageous embodiment of the system, the extension spring is further configured to restore the lever arm to its original position. The home position is the position of the lever arm where the braking force is not applied to the motor belt.

The extension spring provides support to the lever arm in a manner that exerts a force on the first end of the lever arm through the plunger when power fails, the extension spring elongates and allows for smooth movement of the lever arm. Further, when the power becomes active and the plunger is retracted, the extension spring compresses to its original state, allowing the lever arm to return smoothly to its original position without any deformation. Accordingly, the extension spring serves as a shock-absorbing restriction member.

In an advantageous embodiment of the invention, the method further comprises performing by the linear drive member at least one of the following: the braking force is applied through the brake pad when the power to the linear drive member fails, and the braking force applied to the brake pad is removed when the power is active.

In an advantageous embodiment of the invention, the method further comprises positioning the lever arm relative to the motor pulley in such a way that the axis of rotation of the lever arm is parallel to the axis of rotation of the motor pulley.

This allows the lever arm to be used as a force amplifier such that the braking force applied on the first end of the lever arm is amplified when transferred to the second end of the lever arm.

Hereinafter, embodiments of the system presented herein will be described. The proposed system for controlling elevator car doors is incorporated in the elevator car door panel. The elevator car door panel includes various existing components operatively coupled to a motor belt that is movable over a motor pulley to facilitate opening and closing of the elevator car door.

In one embodiment, a system for controlling elevator car doors includes a linear drive member disposed on a beam. In one embodiment, the linear drive member may be a solenoid including a coil former. In another embodiment, the linear drive member may be a pneumatic piston, preferably controlled by a pneumatic switch. The linear drive member receives a plunger having a first end and a second end. When the power to the elevator is active, the plunger remains retracted within the linear drive member. The plunger is released from the linear drive member when power to the elevator fails, or when a conventional elevator door operating system fails. The second end of the plunger is also connected to one end of the elongate member.

The system also includes a lever arm having a first end that pivots relative to the free end of the elongated member. The second end of the lever arm is rotatably pivoted at a predetermined distance from the motor pulley such that the axis of rotation of the lever arm is parallel to the axis of rotation of the motor pulley. The lever arm is also connected to the brake pad in such a way that the brake pad is located between the lever arm and the motor band. However, when the power to the elevator car doors is active, the brake pads are not in contact with the motor belt. Further, according to one aspect of the invention, the brake pad is positioned closer to the second end of the lever arm than the first end of the lever arm. However, the brake pad may also be placed at a different location between the first and second ends of the lever arm. In one embodiment, the brake pad is made of a friction material, such as rubber, ethylene Propylene Diene Monomer (EPDM), or a polymer-based compound.

In one embodiment, the system further comprises a spring capable of exerting a force on the plunger to facilitate smooth linear movement of the plunger. The spring may be arranged in a system according to one or more exemplary embodiments. For example, according to one exemplary embodiment, a spring may be fitted around the plunger. According to another exemplary embodiment, the spring may be housed within the linear drive member. According to a further exemplary embodiment, the spring may be placed adjacent to the linear drive member.

In another embodiment, the system further comprises a counterweight placed on the linear drive member to exert a force on the plunger to facilitate smooth linear movement of the plunger.

The plunger is released from the linear drive member during a power drop, or during a system failure. A force is applied to the first end of the plunger by a spring or by a weight placed on the linear drive member. The force exerted on the first end of the plunger is transferred to the lever arm at a first end that pivots at the free end of the elongate member. The force transferred to the first end of the lever arm acts as a braking force. The braking force applied to the first end of the lever arm is transferred to the second end of the lever arm, which is amplified as the lever arm acts as a force amplifier. The amplified braking force is applied to the motor belt via the brake pads, thereby suppressing the movement of the motor belt and allowing smooth movement of the elevator car door.

The system may also include an extension spring having a first end attached to the elevator door panel and a second end in contact with the lever arm. The extension spring is configured to restore or assist the lever arm to its original position (i.e., the position prior to the application of the braking force) and to prevent any deformation of the lever arm.

It should be noted that possible features and advantages of embodiments of the present invention are described herein, in part, with respect to a system for controlling elevator car doors, and in part, with respect to a method of retrofitting elevator car doors to incorporate a system for controlling elevator car doors. Those skilled in the art will recognize that features may be transferred from one embodiment to another as appropriate, and that modifications, adaptations, combinations, and/or substitutions, etc. of features may be made to arrive at other embodiments of the invention.

Drawings

Hereinafter, advantageous embodiments of the present invention will be described with reference to the accompanying drawings. However, neither the drawings nor the description should be interpreted as limiting the invention.

Fig. 1A and 1B illustrate side views of a system 100 for controlling elevator car doors before and after brake application, respectively, according to an embodiment of this disclosure;

FIG. 2 illustrates a free body diagram 200 of the operation of a lever arm as a force amplifier according to an embodiment of the present disclosure; and

fig. 3 illustrates a side view of a system 300 for controlling elevator car doors mounted on a beam according to an embodiment of this disclosure.

The figures are merely schematic and are not drawn to scale. The same reference numerals indicate the same or similar features.

Detailed Description

Fig. 1A and 1B illustrate side views of a system 100 (hereinafter "system 100") for controlling a beam-mounted elevator car door before and after brake application, respectively, according to an embodiment of this disclosure. In one embodiment, the system 100 may be installed in an elevator having a double door or a single door. In another embodiment, the system 100 may be installed in a new elevator or may be installed in a conventional elevator with minimal hardware inclusion. Those skilled in the art will appreciate that the system 100 may be implemented in a variety of environments other than those shown in fig. 1.

The system 100 includes a linear drive member 102 that houses a plunger 104 having a first end and a second end, a spring 108 capable of applying a force to the plunger 104, an elongated member 106, a lever arm 110 having a first end 110a and a second end 110b, the first end 110a being connected to a free end of the elongated member 106, the second end 110b being rotatably pivotable at a predetermined distance from a motor pulley 116. The lever arm 110 is also connected to a brake pad 112 in such a way that the brake pad is located between the lever arm 110 and a motor belt 114, which motor belt 114 is movable on a motor pulley 116 in order to open and close the elevator car door. Furthermore, the axis of rotation of the lever arm 110 is parallel to the axis of rotation of the motor pulley 116. Further, the brake pad 112 is positioned closer to the second end 110b of the lever arm 110 than the first end 110a of the lever arm 110. The system 100 also includes an extension spring 118, the extension spring 118 having a first end attached to the beam and a second end in contact with the lever arm 110. In the embodiment shown in fig. 1A and 1B, the linear drive member 102 is considered to be a solenoid comprising a solenoid coil frame. However, it will be appreciated that any other suitable means (such as a pneumatic piston) may be used as the linear drive member 102.

As described above, the linear drive member 102 (hereinafter referred to as "solenoid 102") houses the plunger 104. During the energized state, or in other words when the power to the elevator is active, the plunger 104 is in a retracted position within the solenoid 102, as shown in fig. 1A, and the extension spring 118 is in contact with the lever arm 110 to support the lever arm 110 in its current position. Furthermore, when the electricity of the elevator is active, the brake pad 112 is not in contact with the motor belt 114, or in other words, the brake pad 112 is in a lifted state.

However, during a power outage, or due to a failure of the door operating system when the elevator is at a floor, the solenoid 102 releases the plunger 104, as shown in fig. 1B, to provide an emergency braking mechanism to prevent the elevator car door from closing at an uncontrolled rate. Further, as described above, the system 100 includes a spring 108, the spring 108 being capable of applying a force to the first end of the plunger 104 to allow smooth linear movement of the plunger 104. In the exemplary embodiment shown in fig. 1B, a spring 108 is fitted around the plunger 104. However, one skilled in the art must note that springs may be disposed in a system in accordance with one or more exemplary embodiments. For example, according to another exemplary embodiment, the spring may be housed within the linear drive member 102 or disposed adjacent to the linear drive component 102. According to the exemplary embodiment shown in fig. 1A and 1B, one end of the spring 108 is inserted into the coil frame of the solenoid 102, and a second end of the spring 108 is attached to one end of the elongated member 106. During a power outage or during a malfunction of a conventional door operating system, when the solenoid 102 releases the plunger 104, the spring 108 expands, allowing smooth movement of the plunger 104 toward the elongated member 106. The force exerted by the plunger 104 on one end of the elongate member 106 is transferred to the first end 110a of the lever arm 110 that pivots at the free end of the elongate member 106. Since the rotational axis of the lever arm 110 is parallel to the rotational axis of the motor pulley 116, the lever arm 110 acts as a force amplifier, thus amplifying the braking force as it is transferred from the first end 110a of the lever arm 110 to the second end 110b thereof.

According to another embodiment, the spring 108 may be housed within the linear drive member 102 with one end connected to a first end of the plunger 104. A second end of the plunger 104 is connected to an end of the elongate member 106. During a power outage or during a failure of a conventional door operating system, the spring 108 exerts a force on the first end of the plunger 104, which is transferred to the first end of the lever arm 110 that pivots at the free end of the elongated member 106. Since the rotational axis of the lever arm 110 is parallel to the rotational axis of the motor pulley 116, the lever arm 110 acts as a force amplifier, thus amplifying the braking force as it is transferred from the first end 110a of the lever arm 110 to the second end 110b thereof.

Further, the amplified braking force is applied to the motor belt 114 through a brake pad 112 disposed between the lever arm 110 and the motor belt 114, which inhibits movement of the motor belt 114, thereby controlling the elevator car door. In this case, the brake pad 112 is in contact with the motor belt 114.

According to an embodiment of the invention, the lever arm 110 operates as a force amplifier as shown in fig. 2. Fig. 2 depicts the force (F) exerted on the first end 202a of the lever arm 202 _s ) And an exemplary free body diagram 200 of the force (N) applied to the motor band 206 by the brake pad 204 attached to the second end 202b of the lever arm 202. Force F _s And N form a couple. As an exemplary embodiment, F _s Taken as 15N, F _s The vertical distance (X1) to the axis of rotation (i.e., point a) was taken to be 115.5mm. Similarly, the perpendicular distance (X2) of N from the rotation axis (i.e., point a) was taken to be 21.5mm. Now, by applying the torque principle, i.e. counter-clockwise torque is equal to clockwise torque, i.e. nxx2=f _s X1, the force (N) exerted by the brake pad 204 on the motor belt 206 is obtained as 80.5N. Thus, by applying a force (F _s ) With the lever 202, a greater braking force (N) can be obtained, which is therefore advantageous since it allows the use of solenoids of smaller dimensions, thus reducing the bulk of the system 100 and making the system 100 space-efficient. Those skilled in the art will note that F is taken in FIG. 2 _s The values of X1, X2, and N are exemplary only for better understanding of the benefits achieved through the use of lever arm 110 and should not be construed as limiting the scope of the present invention.

Fig. 3 illustrates a side view of a system 300 (hereinafter "system 300") for controlling a beam-mounted elevator car door according to an embodiment of this disclosure. In one embodiment, the system 300 may be installed in an elevator having a double door or a single door. In another embodiment, system 300 may be installed in a new elevator or may be installed in a conventional elevator with minimal hardware inclusion. Those skilled in the art will appreciate that the system 300 may be implemented in a variety of environments other than those shown in fig. 1.

The system 300 includes a linear drive member 302, the linear drive member 302 housing a plunger 304 having a first end and a second end, a weight 306 disposed on the linear drive member 302 by a movable device 308 and capable of applying a force to the first end of the plunger 304, an elongated member 310 having one end connected to the second end of the plunger 304, a lever arm 312 having a first end 312a and a second end 312b, the first end 312a connected to a free end of the elongated member 310, the second end 312b rotatably pivoted at a predetermined distance from a motor pulley 318. The lever arm 312 is also connected to a brake pad 314 such that the brake pad 314 is located between the lever arm 110 and a motor belt 316, the motor belt 316 being movable on a motor pulley 318 to facilitate opening and closing of the elevator car door. Further, the axis of rotation of the lever arm 312 is parallel to the axis of rotation of the motor pulley 318. In addition, the brake pad 314 is positioned closer to the second end 312b of the lever arm 312 than the first end 312a of the lever arm 312. The system 300 also includes an extension spring 320, the extension spring 320 having a first end attached to the beam and a second end in contact with the lever arm 312. In the embodiment shown in fig. 3, the linear drive member 302 is considered to be a solenoid that includes a solenoid coil frame. However, it will be appreciated that any other suitable means (such as a pneumatic piston) may be used as the linear drive member 302.

As described above, the linear drive member 302 (hereinafter referred to as "solenoid 302") houses the plunger 304. During the energized state, or in other words when the power to the elevator is active, the plunger is in a retracted position within the solenoid 302, as shown in fig. 3, and the extension spring 320 is in contact with the lever arm 312 to support the lever arm 312 in its current position. Furthermore, when the electricity of the elevator is active, the brake pad 314 is not in contact with the motor belt, or in other words in a lifted state.

However, during a power outage, or due to a failure of the door operating system when the elevator is at a floor, the solenoid 302 releases the plunger 304 (not shown, similar to fig. 1B) to provide an emergency braking mechanism to prevent the elevator car door from closing at an uncontrolled rate. Further, as described above, the system 300 includes a weight 306, the weight 306 being capable of exerting a force on the first end of the plunger 304 via the movable device 308 to allow smooth linear movement of the plunger 304.

Since the second end of the plunger 304 is connected to one end of the elongate member 310, the free end of the elongate member 310 is also connected to the first end 312a of the lever arm 312, the force exerted on the plunger 304 is transferred to the first end 312a of the lever arm 312 as a braking force. Since the axis of rotation of the lever arm 312 is parallel to the axis of rotation of the motor pulley 318, the lever arm 312 acts as a force amplifier, thus amplifying the braking force as it is transferred from the first end 312a of the lever arm 312 to the second end 312b thereof.

Further, the amplified braking force is applied to the motor belt 316 through a brake pad 314 disposed between the lever arm 312 and the motor belt 316 and inhibiting movement of the motor belt 316, thereby controlling the elevator car door. In this case, the brake pad 314 is in contact with the motor band 316.

The embodiment of the system 300 (shown in fig. 3) that uses the weight 306 to apply a force to the plunger 304 provides additional advantages. For example, the force exerted on the plunger 304 by the weight 306 remains constant, which allows a desired braking force to be conveniently obtained.

The description of an embodiment having multiple components operably coupled to each other does not imply that all such components are required. Instead, various optional components are described to illustrate the wide variety of possible embodiments of the present invention.

When a single device or article is described herein, it will be apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article, or a different number of devices/articles may be used in place of the number of devices or programs shown. The functions and/or features of the device may alternatively be embodied by one or more other devices that are not explicitly described as having such functions/features. Thus, other embodiments of the invention need not include the device itself.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the scope of the invention is not limited by this detailed description, but rather by any claims presented on this basis. Accordingly, the examples of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

Although various aspects and embodiments are disclosed herein in connection with elevators, aspects of the present disclosure may also be applied in connection with other types of conveying or transporting devices, such as elevators, escalators, moving walkways, wheelchair elevators, etc., as will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.

Claims

1. A system for controlling elevator car doors having elevator car door panels moving along a beam, the elevator car door panels being operably coupled to a motor belt (114, 206, 316) movable over a motor pulley (116, 208, 318) to open and close the elevator car doors, the system comprising:

a linear drive member (102, 302) disposed on the beam, housing a plunger (104, 304) connected to one end of an elongate component (106, 310);

a counterweight (306) placed on the linear drive member (302) via a movable device (308) capable of exerting a force on the plunger (304) such that the plunger (304) protrudes from the linear drive member (302); or (b)

-a spring (108) capable of exerting a force on the plunger (104) such that the plunger (104) protrudes from the linear drive member (102);

a lever arm (110, 202, 312) having a first end (110 a, 202a, 312 a) that pivots relative to a free end of the elongated member (106, 310) and a second end (110 b, 202b, 312 b) that is rotatably pivotable such that the second end (110 b, 202b, 312 b) of the lever arm (110, 202, 312) is located at a predetermined distance from the motor pulley (116, 208, 318) and the lever arm (110, 202, 312) is further connected to a brake pad (112, 204, 314),

wherein a braking force is applied to the first end (110 a, 202a, 312 a) of the lever arm (110, 202, 312) by a free end of the elongated member (106, 310) due to a force applied to the plunger (304, 104) by the counterweight (306) or by the spring (108), and the lever arm (110, 202, 312) moves against the predetermined distance, and the lever arm (110, 202, 312) applies an amplified braking force at the brake pad (112, 204, 314), wherein the braking force is used to brake the motor belt (114, 206, 316) to brake movement of the elevator car door.

2. The system of claim 1, further comprising an extension spring (118, 320) disposed on the beam and configured to prevent deformation of the lever arm (110, 202, 312).

3. The system of claim 2, wherein the extension spring (118, 320) is further configured to return the lever arm (110, 202, 312) to its original position, wherein the braking force is not applied to the motor band (114, 206, 316) in the original position.

4. The system as recited in claim 1, wherein the linear drive member (102, 302) includes at least one of a solenoid or a pneumatic piston.

5. The system of claim 1, wherein the lever arm (110, 202, 312) is positionable relative to the motor pulley (116, 208, 318) such that an axis of rotation of the lever arm (110, 202, 312) is parallel to an axis of rotation of the motor pulley (116, 208, 318).

6. The system of claim 1, wherein the brake pad (112, 204, 314) comprises a friction material bonded to a surface of the brake pad.

7. The system of claim 1, wherein the brake pad (112, 204, 314) is positioned closer to the second end (110 b, 202b, 312 b) of the lever arm (110, 202, 312) than the first end (110 a, 202a, 312 a) of the lever arm (110, 202, 312).

8. The system of claim 1, wherein the brake pad (112, 204, 314) is movable such that the motor belt (114, 206, 316) is compressed between the brake pad (112, 204, 314) and the motor pulley (116, 208, 318) to generate a braking force.

9. The system of claim 1, wherein the linear drive member (102, 302) is configured to perform at least one of:

when the power to the linear drive member (102, 302) fails, a braking force is applied through the brake pad (112, 204, 314), and

when the electric power is active, the braking force applied to the brake pad (112, 204, 314) is removed.

10. A method of retrofitting an elevator car door having an elevator car door panel moving along a beam, the elevator car door panel being operably coupled to a motor belt (114, 206, 316) movable over a motor pulley (116, 208, 318) to open and close the elevator car door, the method comprising providing the system of claim 1, wherein:

the lever arm (110, 202, 312) is positioned such that the second end (110 b, 202b, 312 b) of the lever arm (110, 202, 312) is rotatably pivotable at a predetermined distance from the motor pulley (116, 208, 318), and the lever arm (110, 202, 312) is also connected to the brake pad (112, 204, 314), and

the lever arm (110, 202, 312) applies an amplified braking force at the brake pad (112, 204, 314), wherein the braking force is used to brake the motor belt (114, 206, 316) to brake the movement of the elevator car door.

11. The method of claim 10, further comprising performing, by the linear drive member (102, 302), at least one of:

12. The method of claim 10, comprising positioning the lever arm (110, 202, 312) relative to the motor pulley (116, 208, 318) such that an axis of rotation of the lever arm (110, 202, 312) is parallel to an axis of rotation of the motor pulley (116, 208, 318).

13. A method of safely closing an elevator car door, wherein the elevator car door comprises a system according to any of claims 1-9, the method comprising:

in case of a power drop, power is removed from the linear drive member (102, 302) such that the lever arm (110, 202, 312) applies an amplified braking force at the brake pad (112, 204, 314), wherein the braking force is used to brake the motor belt (114, 206, 316) to brake the movement of the elevator car door.