HK1196120B - Adjustable safety brake - Google Patents

Description

Adjustable safety brake

Background

Elevator systems include a variety of control devices for maintaining control over elevator car movement. The motor causes the desired movement of the elevator car to transport passengers to their intended destinations. A brake associated with the motor prevents the elevator car from moving when it is e.g. stopped at the floor requested by the passenger. A brake associated with the motor is used to limit the movement or speed of the elevator car under most conditions.

The elevator car or counterweight can move at a speed greater than the desired speed. The elevator system includes an auxiliary brake, sometimes referred to as a safety device, for stopping the elevator car when the elevator is traveling at a faster speed than desired. Elevator safety devices are typically designed to stop the elevator car at a certain deceleration based on the assumption that the elevator car has full load. When the safety gear is engaged (engage) and there are only few passengers in the car, the deceleration of the car is greater because the car is lighter than in the full load case. Such higher deceleration can cause unpleasant or even uncomfortable stops for passengers inside the car.

Disclosure of Invention

The invention relates to the adjustment of a braking device. According to an aspect of the invention, the brake device has a blocking member and a first brake member and a second brake member movable relative to each other. The first brake member is fixed to the blocking member, and a position of the blocking member relative to the first brake member is adjustable by inserting an adjustment member between the blocking member and the first brake member.

Alternatively, in this or other aspects of the invention, the braking device can be an asymmetric safety device, such as used in an elevator system.

Alternatively, in this or other aspects of the invention, the first brake member may be a fixed wedge.

Alternatively, in this or other aspects of the invention, the brake device may also include a modulation control device that controls displacement of the modulation member relative to the first brake member.

Alternatively, in this or other aspects of the invention, the adjustment control device receives the signal and controls the displacement of the adjustment member based on the signal.

Alternatively, in this or other aspects of the invention, the signal sent to the adjustment control device is responsive to the load.

According to yet another aspect of the present invention, a method for adjusting a braking force of a braking device having a blocking member and a first braking member comprises: receiving a signal responsive to a load; and then adjusting a position of the adjustment member between the blocking member and the first brake member.

Alternatively, in this or other aspects of the invention, the method may include the step of determining the load. Furthermore, the determination of the load may take place before each run of the elevator system.

According to yet another aspect of the invention, the braking device is an elevator safety device that includes a stop, a fixed wedge, and an adjustment member between the stop and the first braking member.

Drawings

Fig. 1 schematically illustrates selected portions of an elevator system including a braking system.

Fig. 2 shows a schematic cross-sectional view of the braking device taken along the plane a-a in one embodiment of the invention.

Fig. 3 shows an exemplary cross-sectional view of the braking device in adjustment.

Fig. 4 shows an example of a top view of the first brake member and the adjustment member.

Fig. 5 shows an example braking device adjusted based on the load in the car.

Detailed Description

Fig. 1 schematically illustrates an example elevator system 20, the example elevator system 20 having an elevator car 22 that moves along guide rails 24 using ropes 32 in a known manner. The governor (governor) device 30 prevents the elevator car 22 from exceeding a maximum speed. The example governor device 30 includes a governor rope 32, the governor rope 32 traveling with the elevator car 22. The governor sheave 34 and the tension sheave 36 are located at opposite ends of the loop formed by the governor rope 32.

The illustrated governor device 30 operates in a known manner. In the event that the elevator car 22 moves too quickly, the governor device 30 trips (trips) and applies a braking force to the governor sheave 34, which causes the governor rope 32 to pull the mechanical linkage 38 upward to actuate the braking device 40 supported on the elevator car 22. The braking device 40 applies a braking force to the guide rails 24 to prevent further movement of the elevator car 22.

Fig. 2 shows an example of a cross section of the braking device 40 taken along the plane a-a. The brake device 40 has a first brake member 44, a blocking member 42 and a second brake member 46. In one embodiment of the invention the elevator braking device is a safety device, more particularly an asymmetrical safety device. The first brake member 44 is a fixed wedge and the second brake member 46 is a sliding wedge. The second detent frame 46 is connected to the jaw 62 via at least one biasing member 47. Jaw 47 is slidably engaged with the angled edge of housing 64. The braking device 40 has a housing 45, the housing 45 configured to be fixedly connected to the elevator car 22 (see fig. 1). At least one fastener 54 secures the first brake member 44 to the blocking member 42. Exemplary fasteners include bolts, pins, worm gears, or any similar device. As depicted in this figure, the first stop member 44 is flush with the surface 43 of the blocking member 42. At least one adjustment member 50 is positioned between the inner side of blocking member 42 and groove 66 of first brake member 44. As discussed below, the adjustment member 50 allows the brake member 44 to be positioned at different positions relative to the blocking member 42 in order to adjust the braking force of the brake device 40.

The adjustment member 50 may be a spacer, a shim, or any other similar spacing device. The adjustment member may allow for only a single adjustment of the braking member 44 relative to the blocking member 42 (e.g., the adjustment member 50 has a constant thickness), or multiple adjustments of the braking member 44 relative to the blocking member 42. In one example, the trim member 50 can have steps 60, wherein each step 60 of the trim member forms a unique distance between the first brake member 44 and the rail 24. In alternative examples, the trim member 50 may have different thicknesses to create even more possible distances than using the aforementioned step 60. An example adjustment control 52 (see fig. 4) may separate the first brake member 44 from the blocking member 42 by applying a force to the fastener 54. As depicted in fig. 3, this movement creates a space between first brake member 44 and blocking member 42 sufficient to allow placement of adjustment member 50 therebetween. The second adjustment control device 52 shifts the adjustment member to a desired position between the first brake member 44 and the blocking member 42. The plurality of modulation control devices 52 that move the first braking member 44 and the modulation member 50, respectively, may be solenoids, actuators, or some other electromechanical devices. Fig. 4 depicts a top view of an exemplary first brake member 44 and its corresponding adjustment member 50 positioned within a groove 66 of the first brake member. The plurality of adjustment members 50 may be connected to a common rod 56, the common rod 56 being controlled by the adjustment control device 52. The adjustment control device 52 moves the rod 56 to uniformly adjust the position of the adjustment member 50 relative to the first brake member 44. This movement controls which portions, if any, of the adjustment member 50 the first brake member 44 will contact. Alternatively, the trim member 50 may be separate (i.e., without a common rod 56) and have its own trim control device or devices 52.

When the adjustment member 50 is positioned between the first brake member 44 and the blocking member 42, the distance or gap between the first brake member 44 and the rail 24 is less (as depicted in fig. 5) than if the first brake member 44 were disposed flush against the surface 43 of the blocking member 42 (i.e., the adjustment member 50 is fully located within the groove 66). The clearance between the first brake member 44 and the blocking member 42 ultimately determines the resilient normal force exerted by the brake members 44, 46 on the rail. Because such a resilient normal force resists movement of the car 22, the distance between the first brake member 44 and the blocking member 42 can be adjusted to provide a desired resilient normal force based on the actual load in the car 22, thereby providing a more comfortable stop for the passengers. Also, by using a plurality of adjustment members 50, the distance between the first brake member 44 and the rail 24 can be adjusted more accurately and thus the resilient normal force is closer to the ideal force based on the weight of the load in the car 22.

To assist in adjusting the clearance between the first brake member 44 and the blocking member 42, for example to make an emergency stop less severe for passengers in the car 22, the system may first detect the load in the car at each run. Methods for detecting the load in the car may include, but are not limited to, measuring the load directly, such as by using a load weighing device in the car, or indirectly, such as by measuring the tension on the elevator tension members. A controller (not shown) receives the load information, determines an appropriate gap between the first brake member 44 and the blocking member 42 based on the load information, and sends a signal to the adjustment control device 52 to position the adjustment member 50, if necessary. The controller can be added to existing elevator components or to a separate unit. The adjustment control 52 applies a force to the fastener 54 to displace the first brake member 44 toward the rail 24 and create a gap between the first brake member 44 and the blocking member 42 to allow movement of the adjustment member 50 therein. After the first brake member 44 is spaced from the adjustment member 50 and the blocking member 42, the second adjustment control device 52 moves the plurality of adjustment members 50 to a position that forms a desired spacing between the blocking member 42 and the first brake member 44. The adjustment control 52 then releases its pressure on the fastener 54, allowing the spring 48 to reposition the first brake member 44 adjacent the blocking member 42 (if possible) or adjacent the adjustment member 50, thereby sandwiching the adjustment member 50 between the blocking member 42 and the first brake member 44. Thereafter, the elevator system 20 can perform its operation.

Claims (16)

1. A brake apparatus comprising:

a blocking member;

a first brake member for applying a braking force, the first brake member being fixed to the blocking member;

a second brake member movable relative to the first brake member to apply a braking force; and

at least one adjustment member positioned between the first brake member and the blocking member to adjust a distance between the first brake member and the blocking member along an axis perpendicular to a braking surface of the first brake member.

2. A braking apparatus in accordance with claim 1, characterised in that the braking apparatus is an asymmetric safety apparatus.

3. A braking apparatus in accordance with claim 1, characterised in that the first braking member is a fixed wedge.

4. The braking apparatus according to claim 1, characterized by further comprising:

at least one adjustment control device for controlling the displacement of the adjustment member.

5. A braking apparatus in accordance with claim 4, characterised in that the adjustment control means receives a signal and controls the displacement of the adjustment member on the basis of the signal.

6. A braking apparatus in accordance with claim 5, characterised in that the signal is responsive to a load.

7. The braking apparatus of claim 6, further comprising a controller, wherein the controller receives a signal indicative of a load and sends a signal to the regulation control apparatus in response to the load.

8. A method for adjusting the braking force of a braking device according to claim 1, the method comprising:

receiving a signal responsive to a load; and

adjusting a position of an adjustment member between the first brake member and the blocking member.

9. The method of claim 8, further comprising: and determining the load.

10. The method of claim 9, wherein the load determining step occurs before each elevator system run.

11. An elevator safety device comprising:

fixing the wedge block;

a blocking member; and

at least one adjustment member located between the fixed wedge and a stop to control the position of the fixed wedge relative to the stop along an axis perpendicular to a braking surface of the fixed wedge.

12. An elevator safety according to claim 11, including at least one adjustment control for changing the position of the adjustment member relative to the fixed wedge.

13. An elevator safety according to claim 11, including a second adjustment control for adjusting the position of the fixed wedge relative to the stop.

14. An elevator safety according to claim 11, wherein the adjustment control receives a signal to adjust the position of the adjustment member accordingly.

15. The elevator safety of claim 11 wherein the signal is responsive to a load in the elevator car.

16. The elevator safety of claim 15, further comprising a controller, wherein the controller receives a signal indicative of a load and sends a signal to the adjustment control in response to the load.