EP1853504A1 - Braking or interception device for a lift cabin - Google Patents

Abstract

The invention relates to a braking or interception device for a lift cabin, which is guided in a shaft along vertical guide tracks (2). To permit a simple construction, the braking organ is configured by a roller (9), whose axis runs perpendicular to the longitudinal direction of the guide track (2) and whose outer surface is configured as a friction surface (12). Said roller is displaceably guided by stepped shoulders (11) in a gap (20) of a pressure body (19) that runs parallel to the associated guide track (2), said gap (20) having a groove (21), which runs nearer to the guide track (2) at least towards one end. The roller (9) is connected to an arresting organ and is pre-tensioned against the guide track (2) with the aid of a spring (28). When the arresting organ releases the roller (9), the latter (9) is pressed against the guide track (2) and rolls along the latter until it reaches the end of the groove (21), where it becomes firmly clamped, thus braking the lift cabin by friction.

Description

 description

BRAKE- BZW. FAN DEVICE FOR A LIFT CABIN

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 or catching devices which serve to decelerate an elevator car in the event of an impermissibly 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 is carried out in known such devices of a fixed in the shaft or engine room speed limiter, which is set in a movement of the elevator car in rotation. 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.

However, 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, for example, 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 be an emergency stop trigger.

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

For lifts 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, a braking or catching device of the type mentioned was known in which the pressure body has two inclined ramp surfaces on 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 is de-energized, the springs press the brake members into the gap to be narrowed between the ramp surfaces of the pressure hull and the guide rail, resulting in frictional engagement between the brake members and the guide rail and further increasing the contact pressure of the brake members ,

However, results in the known case that these are reinforcing

Braking effect arises only when 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 can lead to a one-sided attack of the brake elements on the guide rails, especially in the case of positional errors of the guide rails, causing a tilting of the elevator car and subsequently to very serious damage to the guide rails can come. This is because the extent of the brake boost depends on the braking force itself (ie the friction). Is the friction on one side less so the contact pressure is lower, so that the braking force is significantly reduced.

Disclosure of the invention

Technical problem

The aim of the present invention is to avoid these disadvantages and a

To propose device of the type mentioned, which is characterized by a simple structure and a high degree of reliability. It should be suitable for both mechanical trip systems and electrical tripping systems. 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.

By the proposed measures it is ensured that the friction surface of the brake member comes to rest on the guide rail with exactly the predetermined pressure, whereby the risk of uneven contact pressure is avoided on a guide rail, as may occur in the known solution described above. By the design of the depth of the gap and the groove (which form a kind of backdrop) can be set any desired delay in braking the elevator car in a simple manner. The roll, once in contact with the guide rail, unrolls therefrom and is thereby forced into the gap to the end, i. until the shoulders touch the gap next to the groove. The distance there between the guide rail and the groove - which is slightly smaller than the diameter of the roller - together with the elasticity of the material determines the contact pressure.

Due to the features of claim 2, a deceleration of the elevator car both in the downward movement as well as a movement can be made possible in a simple manner. In this case, different deceleration values for the different directions of travel can be ensured in a simple manner by appropriate design of the depth of the gap and the groove. Ultimately, the deceleration values when moving upwards should not exceed the value of 1 g (g is the gravitational acceleration), otherwise the passengers would lift off the floor of the elevator car, resulting in a significant risk of falls and thus injuries.

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 3.

By virtue of these measures, a pressure load on the guide rails can be avoided which, in the case of the connection of two different guide rails, can be avoided. ment rails associated with pressure hull over a rigid support could result. 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 4, a weakening of the rigidity of a (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.

A structurally very simple solution results from the features of claim 5.

This makes it possible in a simple manner, to hold the brake member in normal operation at a small distance from the top of the associated guide rail. When triggered, the braking device, the roller is securely brought into contact with the guide rail and begins to rotate, whereby it rolls against one end of the gap and presses more and more to the guide rail and is clamped, causing it to slow down the elevator car. Short description of drawings

The invention will now be explained in more detail with reference to the drawings. 1 shows schematically a brake element according to the invention; Fig. 2 schematically shows a Bremsbzw. Catching device according to the invention in a horizontal section; and FIG. 3 shows this braking or catching device in the direction of the arrow III of FIG. 2. The best way to exploit the invention

As can be seen from Fig. 2, 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 is provided at its two end faces 10 (see FIG. 1) 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 come to rest on the guide rail 2 (see FIG. 2).

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 at its leg 16 a gap 20 in which the roller. 9 is guided. In this case, the gap 20 has a groove 21 which allows the reception of the friction surface 12 (see FIG. 1) of the roller 9.

The roller 9 is rotatably supported on an axis 22 (not shown in Fig. 2, 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 formed as a compression spring and the roller 9 biases 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 it comes to rest with its friction surface 12 (see FIG. 1) on the guide rail 2 (see FIG. 3) and is set in rotation.

The axle 22 of the roller 9 can also be attached to a conventional cable of a conventional speed limiter and be moved by this in 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).

During a downward movement of the elevator car, the roller 9 rotates in a clockwise direction (as viewed in 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 (see FIG. 1) contacts the groove 21 at the location 41 (see FIG. 3), and at the location 42 the shoulders 11 (see FIG. 1) of the roller 9 contact the gap 20 (see FIG Fig. 3) next to the groove 21. 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) is not affected. 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 from. The gap 20 (or the groove 21) has approximately in the middle of a recess 31 for

Determination of 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.

In the embodiment shown in Fig. 3 is to reduce the

Stiffness of the pressure body 19 in the lower region of a cut 32 is provided. 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

claims Braking or catching device for an elevator car, which is guided in a shaft along vertical guide rails (2), wherein one with a friction surface (12) provided braking member in a held on the elevator car pressure body (19) of the braking device movably is and from a determined by a retaining member inactive rest position to a guide rail (2) can be brought into contact, characterized in that the braking member by a roller (9) is formed, whose axis is normal to the longitudinal direction of the guide rail (2) and the lateral surface thereof is formed as a friction surface (12) and which is guided displaceably with offset shoulders (11) in a parallel to the associated guide rail (2) gap (20) of the pressure body (19), wherein the gap (20) has a groove (21) for Receiving the friction surface (12) of the roller (9), that the groove (21) against at least one end to a decreasing distance to the Führungssch (2), so that the roller (9) rests in this position with its friction surface (12) on the one hand on the guide rail (2) and on the other hand in the groove (21) (position 41) that the roller (9) further in this position with its shoulders (11) against the gap (20) next to the groove (21) abuts (position 42), so that a further displacement of the roller (9) is prevented, and that the roller (9) with its inactive rest position determining retaining member is connected. Braking or catching device according to claim 1, characterized in that the gap (20) and the groove (21) extending from one of the inactive rest position defining recess (31) from both sides. Braking or catching device according to claim 1 or 2, characterized in that the pressure body (19) engages behind the guide rail (2). Braking or catching device according to claim 2 and 3, characterized in that the pressure body (19) in the region of the downwardly extending portion of the gap (20) has a perpendicular to the guide rail (2) extending incision (32). Braking or catching device according to one of claims 1 to 4, characterized in that the retaining member has a pivotally held solenoid and the roller (9) by a spring (28) is biased against the associated guide rail (2).