EP1853504B9 - Braking or interception device for a lift cabin - Google Patents

Description

Technical environment

The invention relates to a braking or catching device for an elevator car according to the preamble of claim 1.

Lifts are provided with braking devices which serve to decelerate an elevator car in the event of an inadmissibly high driving speed, as e.g. can occur in the event of a malfunction of the control or a cable break.

The activation of the catching or braking device takes place in known devices of this type by a speed limiter which is permanently mounted in the shaft or machine room and which is set into rotation during a movement of the elevator car. For this purpose, a self-contained limiter rope is provided, which is deflected on the one hand at the speed limiter (usually at the highest point in the shaft) and on the other hand at a tension roller (usually at the lowest point in the shaft). The governor rope is connected at one point to the brake device of the elevator car, so that it is entrained during a movement of the elevator car. If the speed is too high, the overspeed governor blocks the governor rope, causing the arrestor to trip, causing the elevator car to come to a standstill.

This structure has the advantage that it works purely mechanically and therefore can not be affected by power outages.

He has several disadvantages. On the one hand, it is prone to failure, precisely because it works purely mechanically. If it is heavily contaminated, the centrifugal governor may u.U. only too late (i.e., only at very high speed) trigger.

Another disadvantage is the relatively high cost. Apart from the actual braking device a circulating over the entire shaft rope is necessary, which must be performed up and down and also must be stretched.

Another disadvantage is that this mechanical solution reacts only when a predetermined speed is exceeded. This is often not enough with today's high-speed elevators. Such elevators travel at speeds of e.g. 10 m / s, and they must therefore be braked in good time before reaching the last floor (up and down). If the elevator car is on the first floor in downward travel, a speed of only 5 m / s is already too high and should therefore trigger emergency braking

In order to trigger an emergency braking differentiated an electronic solution is more suitable. There have already been made proposals. By the US 5020640 became a braking device for an elevator in which the speed of the elevator car is determined by means of the drive wheel on which the carrier cable rolls.

For elevators, a counterweight to the elevator car is usually provided. Depending on the design of this counterweight and other constructive factors can sometimes be assumed that the elevator car can only reach too high a speed during the downward movement. Sometimes, however, one has to reckon with the upward movement too high speeds, e.g. if in an empty elevator car this is lighter than the counterweight, so that in case of failure of the control, the elevator car is accelerated by the counterweight upwards.

By the generic US 5366045 A has been known a braking or catching device of the type mentioned, in which the pressure body has two oblique ramp surfaces against which abut two on both sides of a guide rail attacking wedge-shaped brake elements. In this case, the retaining member is formed by a solenoid which holds the brake members against the force of springs in a position in which a gap between the friction surfaces and the respective guide rail remains. If the solenoid de-energized, the springs press the brake members in the upwardly narrowed gap between the ramp surfaces of the pressure hull and the guide rail, resulting in a frictional engagement between the brake elements and the guide rail and the contact pressure of the brake elements is further increased.

However, it results in the known case that this reinforcing braking effect arises only during a downward movement of the elevator car. During an upward movement, the friction frictional engagement between the guide rail and the brake elements reduces the braking force. This is advantageous in that it can be cranked up a decelerated elevator car to the next floor. But it has the disadvantage that during the upward movement no emergency braking can be effected.

In this known solution, there is also the problem that it may come to a one-sided attack of the brake elements on the guide rails, especially in the case of positional errors of the guide rails, which can lead to tilting of the elevator car and subsequently to very serious damage to the guide rails. This is because the extent of the brake boost depends on the braking force itself (ie the friction). If the friction is lower on one side, then the contact pressure is lower, so that the braking force is significantly reduced.

From the EP 0 841 280 A1 is a safety gear with the generic gap, groove and roller design known. However, this safety gear can only be active when driving up the elevator car. In addition, it is dependent on a mechanical release by a speed limiter cable or the like, ie on a triggering device that pulls the role of the first small piece in the gap between the guide rail and the pressure body.

Presentation of the invention Technical task

In contrast, it is the object of the invention to provide a brake and safety gear, which are omnidirectional effect and can be electrically triggered, but which ensures reliability even in case of power failure by it is not ineffective due to power failure.

Technical solution

According to the invention this is achieved in a braking or catching device of the type mentioned by the characterizing features of claim 1. A particular advantage of the measures according to the invention is that the solenoid operates against the bias of the spring and thereby ensures that the braking or catching device is activated in the event of a total power failure, so that even then something can happen.

In order to minimize the risk of damage to the guide rails in case of braking due to an accident, it is advantageous to provide the features of claim 2.

By these measures, a pressure load of the guide rails can be avoided, which could result in the case of the connection of two different guide rails associated pressure body via a rigid support. Moreover, such a braking device is also suitable for elevators whose elevator cars are guided on only one or two guide rails fastened to one and the same wall.

By the features of claim 3, a weakening of the rigidity of the one (the direction of travel of the elevator car upwardly corresponding) section of the pressure body is achieved, whereby the contact pressure of the brake member is reduced during braking during the upward movement of the elevator car. This results in the braking in the direction of travel up a lower delay, whereby a lifting of the passengers from the bottom of the elevator car can be easily avoided.

Brief description of the drawings

The invention will now be explained in more detail with reference to the drawings. It shows: Fig. 1 schematically a brake member according to the invention; Fig. 2 schematically a braking or catching device according to the invention in a horizontal section; and Fig. 3 this braking or catching device in the direction of arrow III of Fig. 2 seen.

Best way to carry out the invention

How out Fig. 2 can be seen, the guide rails 2 a connected via a web 6 with a rail 7 rail head 8.

In a braking or catching device according to the invention, a braking member in the form of a roller 9 is provided, which at its two end faces 10 (see Fig. 1 ) is provided with shoulders 11. The lateral surface of the roller 9 serves as a friction surface 12. For this purpose, it is provided with a knurling or with a friction lining. It is intended to be fixed to the guide rail 2 (see Fig. 2 ) to come to the plant.

The Fig. 2 shows a braking device 14 according to the invention in a horizontal section. This has a pressure body 19, which essentially corresponds to a U-profile, wherein the two legs 16, 16 'in the region of their free ends, the guide rail 2 comprise.

The pressure body 19 has on its leg 16 a gap 20 in which the roller. 9 is guided. In this case, the gap 20 has a groove 21, which receives the friction surface 12 (see Fig. 1 ) of the roller 9 allows.

The roller 9 is rotatable on an axis 22 (in Fig. 2 not shown, see Fig. 3 ), which passes through an opening 23 in the leg 16 and is held in a holder 25.

This holder 25 is surrounded by a spring 28 which is designed as a compression spring and biases the roller 9 in the direction of the guide rail 2. This spring 28 counteracts a solenoid (not shown) which is controlled by a device monitoring the speed of the elevator car. In this case, the solenoid is de-energized when too high a speed of the elevator car is detected. As a result, the spring 28 moves the holder 25 and thus the roller 9 against the guide rail 2, so that this with its friction surface 12 (see Fig. 1 ) on the guide rail 2 (see Fig. 3 ) comes to rest and is set in rotation.

The axle 22 of the roller 9 may also be attached to a conventional cable of a conventional speed limiter and moved therefrom into the narrowing gap 20. Thus, this type of safety gear is capable of being activated electrically (via the de-energized solenoid) or mechanically (via the cable).

As the elevator car descends, the roller 9 rotates clockwise (as viewed in FIG Fig. 3 ). As a result, the roller 9 rolls on the guide rail 2 and rises upwards. Since the distance between the groove 21 and the guide rail 2 to be reduced upward, the roller between the groove 21 and the guide rail 2 is clamped, whereby it rubs in the groove 21 and therefore brakes, so that the elevator car, not shown, comes to a standstill. In the end position, the friction surface 12 touches (see Fig. 1 ) at location 41 (see Fig. 3 ) the groove 21, and at the point 42 the shoulders 11 touch (see Fig. 1 ) of the roller 9 the gap 20 (see Fig. 3 ) at the point 42, the depth of the groove 21 is correspondingly large, so that the friction surface 12 (see Fig. 1 ) There, the groove 21 (see Fig. 3 ) not touched. In this way, the movement path of the roller 9 is limited, without this having a significant influence on the braking force, because the friction in the region of the shoulders 11 (see Fig. 1 ) is relatively low (the shoulders are smooth). By appropriate design of the distance of the groove 21 (see Fig. 3 ) of the guide rail 2, the delays occurring can be predetermined accordingly. Due to the pivotable holder 25 and due to the opening 23, the roller 9 can move freely along the gap 20.

In a braking during the upward travel, in which only lower braking forces are required, the roller 9 rotates counterclockwise and therefore rolls down.

The gap 20 (or the groove 21) has approximately in the middle of a recess 31 for determining the inactive rest position. In this position, the roller 9 is pulled by the energized solenoid. In this case, a distance between the guide rail 2 and the roller 9 remains.

At the in Fig. 3 illustrated embodiment, a recess 32 is provided to reduce the rigidity of the pressure body 19 in the lower region. As a result, a correspondingly lower rigidity is effected in the section corresponding to an upward travel of the pressure body 19, and thus a lower contact pressure of the roller 9, resulting in a lower deceleration during braking.

The latter can also be done by a correspondingly different design of the course of the groove 21 above and below the recess 31.

Claims (3)

1. A braking or catching device for an elevator car guided in a shaft along vertical guide rails (2), wherein a braking organ provided with a friction surface (12) is movably retained in a pressure body (19) of the braking device retained on the elevator car and can be brought to rest on a guide rail (2) from an inactive rest position determined by a retaining organ, the braking organ being formed by a roller (9) whose axis extends normally to the longitudinal direction of the guide rail (2) and whose jacket surface is configured as a friction surface (12) and which, with stepped shoulders (11), is displaceably guided in a gap (20) of the pressure body (19) extending parallel to the associated guide rail (2), the gap (20) comprising a groove (21) for accommodating the friction surface (12) of the roller (9), the groove (21) having a distance from the guide rail (2) that decreases towards at least one end, so that the roller (9), in this position, rests with its friction surface (12) against the guide rail (2) on the one hand, and on the other hand in the groove (21) (position 41), and the roller (9), in this position, moreover rests against the gap (20) next to the groove (21) (position 42) with its shoulders (11), so that a further displacement of the roller (9) is prevented, the roller (9) being connected to the retaining organ determining its inactive rest position, characterised in that the gap (20) and the groove (21) extend from a depression (31) determining the inactive rest position towards both sides, and the retaining organ comprises a pivotably retained solenoid, and the roller (9) is biased by a spring (28) against the associated guide rail (2) in such a way that the spring (28) is configured as a compression spring and biases the roller (9) in the direction towards the guide rail (2), with the solenoid, which is controlled by a device monitoring the speed of the elevator car, counteracting the spring (28), and the solenoid being de-energized when an excessive speed is detected on the elevator car, whereby the spring (28) moves a bracket (25), and thus the roller (9), against the guide rail (2), so that it comes to rest with its friction surface (12) against the guide rail (2), is made to rotate and rolls along the guide rail.
2. A braking or catching device according to claim 1, characterised in that the pressure body (19) reaches behind the guide rail (2).
3. A braking or catching device according to claim 1 or 2, characterised in that the pressure body (19), in the region of the downwardly extending section of the gap (20), has a slot (32) extending perpendicularly to the guide rail (2).

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