RU2444471C2 - Elevator emergent braking system - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed system ensures safety in case elevator cabin exceeds preset speed. It comprises speed limiter arranged elevator cabin and made up of overrunning roller coupling. The latter is fitted in one of roller's shoe. Excess speed of the cabin causes seizure of overrunning coupling case and its turn together with roller shoe. Links connecting overrunning coupling case with catcher tension the latter to brake the cabin.

EFFECT: higher safety, simplified design.

4 cl, 2 dwg

Description

The invention relates to hoisting vehicles, and more specifically to a safety system of elevators with a catcher drive on the cab, and can find application in elevators, including any other elevators, designed to move people and cargo from one floor to another.

Elevators typically include a cab and a counterweight, connected by tensile elements or connecting elements, such as ropes or belts. The power mechanism drives the connecting elements to move the counterweight and the cabin along the elevator shaft. For safety, the elevator is equipped with an emergency braking device for the elevator (Arkhangelsky G.G. Lifts. / Under the general editorship of D.P. Volkov. - M.: ASV Publishing House, 1999. p. 281).

A device for emergency braking, the "speed limiter" according to the patent for invention RU 2034766, published 05/10/1995, which is a centrifugal device. The basis of the design is a drive pulley, on which shaped weights are mounted using fingers. The loads are pivotally connected to each other by a rod on which a pre-compressed spring is installed. The spring is compressed by nuts relative to the stop with an opening for the passage of traction. Due to the presence of traction that synchronizes the movement of goods in the radial direction, their gravity forces are balanced and do not affect the operation of the speed limiter. In case of emergency speeding, the speed limiter pulley rises and the centrifugal forces begin to move the loads from the center to the fixed stops of the ratchet wheel until they engage.

The ratchet wheel is mounted on a drive pulley. The pulley stops, and the cab continues to move, as a result of which the rope spins the shaft with a lever mounted on the cab, acting on catchers and on the motor switch. The cab stops. Since weights and the ratchet wheel are located in a closed cavity of the drive pulley, they are protected from external influences, which increases reliability.

The disadvantage of this design is that the rope, as an actuator between the speed limiter and the cabin, is stretched and requires constant adjustment. In case of fire, the rope burns and loses flexibility. The speed limiter pulley is abraded by the rope and begins to slip, as a result of which it has to be changed. All this reduces the reliability of such an emergency braking device and requires additional labor costs.

Most often, the emergency braking device consists of a speed limiter, the device for switching on catchers and catchers, which interact with the guides. Such devices contain elevators protected by RF patents for inventions No. 2026253 and 2114044. In these elevators, the emergency speed limiting device must be located in the machine room where the elevator drive is located, or in the elevator shaft in the upper part.

Known emergency braking system of the elevator according to the patent for the invention RU 2026253, publ. 01/09/1995. It contains a speed limiter for the cabin, a mechanism for activating the catcher located on the cabin, and the catcher itself, interacting with the guides of the cabin when the speed of its movement is exceeded and on which the cabin is landing. The cab speed limiter is located in the engine room of the elevator and contains a drive pulley enveloped by a rope. At the bottom of the shaft, a pulley is fixed with a load, which is mounted on a rail. The guide is cantilevered through a bracket in the elevator shaft. Both ends of the rope are connected to the lever (traction) of the mechanism for activating the catcher. The lever is spring-loaded to the elevator car with a certain force. The system contains a drive disconnect tap fixed on the rope branch and connected with the lever of the mechanism for activating the catcher above the point of its connection. When the cab speed is exceeded, the tension load rests against the upper limiter. Abrupt braking of the envelope of the drive pulley of the rope provides the trigger mechanism for activating the catcher, landing the cab on the catcher and stopping it. In case of weakening, jamming or wire breakage, the tension load sits on the lower limiter, the layering releases the blocking contact in the emergency shutdown circuit of the drive, thereby stopping the movement of the cab.

In the event of a fire, the speed limiter cable may burn out, which leads to inaction of the emergency system, or slip in the speed limiter pulley. As a result, the cab can break down from a height.

The closest analogue adopted for the prototype is the emergency braking system of the elevator car according to DE 20314938 U1. The prototype system comprises a catcher interacting with the guides of the cabin when its speed is exceeded. It contains a cabin speed limiting mechanism located on the elevator car and connected to two rods of the mechanism for activating the catcher installed on the elevator car.

The speed limiting mechanism in the known device has a complex structure in the form of rollers (bearings) and, in fact, is a differential. And the differential has such a drawback as towing, which can adversely affect the reliability of the catcher. In addition, the presence of a large number of parts of friction units that are subject to wear cannot ensure reliable safety of the elevator.

The basis of the invention is the task of improving the safety of the elevator while simplifying the design.

The technical result consists in the reliable operation of the system and simplify the design.

The problem is solved as follows.

The claimed emergency braking system of the elevator car, as in the prototype, contains a mechanism for limiting the speed of the car, located on the elevator car and connected to two rods of the mechanism for activating the catcher installed on the elevator car, and a catcher interacting with the guides of the car when its speed is exceeded.

Unlike the prototype, the mechanism for limiting the speed of the cabin is made in the form of an overrunning roller clutch, which is coaxially mounted in one of the roller shoes connecting the cabin with its guides. The overrunning roller clutch case is connected to the catcher using two rods of the mechanism for activating the catcher.

The catcher can be made wedge, the wedges are connected using rods to the overrunning clutch housing. It is possible to perform a catcher roller or eccentric.

The main body of the overrunning clutch has an operating mode and a mode for switching on catchers.

An asterisk is usually fixed inside the freewheel roller clutch, which forms a single relationship with the housing using rollers. The rods connecting the overrunning clutch housing and the catcher form an emergency braking system.

The invention meets the criterion of "novelty," since no emergency shutdown device for the elevator car, characterized by the same set of features as the claimed device, was found in known sources of information.

The proposed emergency braking system has a simpler design in comparison with the prototype and analogues. The system does not require additional details, kinematic connections, a rope that wears out over time, a pulley in which the coefficient of friction decreases and stops working.

The main advantage of the elevator is the safety response of the catcher, due to the coaxial connection of the freewheel with the roller shoe on the cab rails, which in turn increases the overall safety of the elevators.

Overspeeding causes the overrunning clutch housing to be pinched and rotated together with the roller shoe, which ensures the catch is pulled up and the cab stops.

Thus, the invention in comparison with the prototype has the following advantages:

- the reliability of the catcher;

- The braking system with a speed limiting mechanism is more compact;

- simplicity of design, which provides a decrease in the cost of the elevator during the life of the unit.

The proposed set of essential distinguishing features, which in their interconnection ensure reliable operation of the system and cabin stop when speeding, is not identified in the prior art.

Therefore, the invention does not explicitly follow from the prior art and meets the condition of "inventive step".

The invention may be better understood by reading the drawings.

Brief Description of the Drawings

Figure 1 is a General view of the inventive system.

Figure 2 - freewheel roller clutch.

A roller shoe 2 is mounted on the guide 1 (FIG. 1). Inside the roller shoe 2 there is a speed limiting mechanism representing an overrunning roller clutch 3.

Clutch 3 is tightly mounted in shoe 2.

The number of rollers in the overrunning clutch is usually from 3 to 8. The clutch consists of a cage (housing) 4, sprocket 5 and rollers (balls) 6, pusher 7 and spring 8 (Figure 2).

A lever system 9 (FIG. 1) is fixed to the housing 4 for actuating the catcher 10. The catcher 10 is located in the rigid body 11.

The lever system 9 consists of two rods.

The system operates as follows.

One way clutch 3 transmits torque in the direction from the master to the driven. A feature of the overrunning clutch is that it transmits torque in only one direction.

The principle of operation of the speed limiting mechanism is based on the centrifugal force of the rotating rollers 6 in the overrunning clutch housing 3. The clutch 3 is driven by a roller shoe 2 moving along the guide 1.

With the normal movement of the elevator car down, the roller cage 3 moves in the same way as the roller shoe 2, as soon as the speed increases, the spring 8 is compressed due to centrifugal force, moving the roller 6 along the sprocket 5.

The rollers 6 of the coupling 3 begin to shift to the periphery, as a result of which the clutch housing 4 is clamped.

The result of clamping the housing 4 of the coupling is its rotation.

The housing of the coupling 4 is rigidly connected with the catcher by means of rods 9. When turning the housing 4, it pulls the rods 9, and those, in turn, pull the catcher 10, clamped in a stationary housing 11. As a result of the friction forces that arise, the cab on which the catcher 10 is mounted, clamps between the rails 1 and stops.

The basis of the design of the catchers 10 are catching devices operating on the basis of self-jamming between the surface of the head of the guide 1 and the structure of the housing 11.

Moreover, the catching device can be made on the basis of the wedge, roller and eccentric type.

The invention is industrially applicable. Its implementation does not cause difficulties for specialists in the field of elevator construction. The device can be repeatedly implemented and, when implemented, can ensure the safety of the elevator.

Claims (4)

1. The emergency braking system of the elevator car, comprising a mechanism for limiting the speed of the car, located on the elevator car and connected to two rods of the mechanism for activating the catcher installed on the elevator car, and a catcher interacting with the guides of the car when its speed is exceeded, characterized in that the limiting mechanism speed is made in the form of a freewheel roller clutch, which is coaxially mounted in one of the roller shoes connecting the cabin with its guides, while the two rods of the gear Ithel connect housing overrunning roller clutch speed limiting mechanism catcher. 2. The emergency braking system according to claim 1, characterized in that the catcher is made wedge-shaped, and the catcher wedges are connected using rods to the overrunning roller clutch case. 3. The emergency braking system according to claim 1, characterized in that the catcher is made roller. 4. The emergency braking system according to claim 1, characterized in that the catcher is made eccentric.

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