ES2412855T3 - Braking or holding device for an elevator car - Google Patents

Abstract

Braking or retaining device for an elevator car, which is guided in a shaft along vertical guide rails (2), where a braking member provided with a friction surface (12) is held movably in a pressure body (19) of the braking device placed in the elevator car and that can be placed from an inactive rest position determined by a retaining member on a guide rail (2), where the braking member is configured by a roller (9) whose axis runs normal to the longitudinal direction of the guide rail (2) and whose enveloping surface is configured as a friction surface (12) and which is displaceably guided with lowered edges (11) in a space (20) of the pressure body (19) that runs parallel to the assigned guide rail (2), where the space (20) has a groove (21) for housing the friction surface (12) of the roller (9), where the groove (21) has in dir ection towards at least one end a distance that is reduced in relation to the guide rail (2), so that the roller (9) fits in this position with its friction surface (12) on one side to the guide rail (2) and on the other hand to the slot (21) (position 41) and the roller (9) also fits in this position with its flanges (11) to the space (20) next to the slot (21) (position 42), so that a further displacement of the roller (9) is avoided, where the roller (9) is connected to the retaining member that determines its inactive rest position, characterized in that the space (20) and the groove (21) are extend on both sides from a depression (31) that determines the inactive rest position, and the retaining member has a rotatably housed solenoid and the roller (9) is prestressed by a spring (28) against the assigned guide rail (2). , in such a way that the spring (28) is configured as a compression spring and prestresses the roller (9) in the direction tion towards the guide rail (2), where the solenoid, which is controlled by an elevator car speed monitoring device, acts against the spring (28) and the solenoid is de-energized when too high car speed is detected. so that the spring (28) moves a support (25) and with it the roller (9) against the guide rail (2), so that it adjusts with its friction surface (12) to the guide rail (2). ), sets it in rotation and moves on the guide rail.

Description

Braking or holding device for an elevator car

Technical field

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

The elevators are provided with braking or retained devices, which serve to brake an elevator car in the event of an inadmissibly high travel speed, as may occur, for example, in the event of a malfunction of the control or a cable breakage. .

Activation of the retained or braking device occurs in known devices of this type from a speed limiter fixedly mounted in the recess or the engine room, which is rotated with a movement of the elevator car. For this purpose, a closed limiting cable is provided on itself which is deflected by one part in the speed limiter (usually at the highest point of the gap) and on the other hand in a tension pulley (usually at the lowest point in the gap ). The limiting cable is connected at one point with the braking or retaining device of the elevator car, so that it is dragged with a movement of the elevator car. With a speed that is too high, the speed limiter locks the limiter cable, thereby activating the braking or holding device, so that the elevator car is stopped.

This construction has the advantage that it works completely mechanically and therefore cannot be harmed in case of power failure.

But it has however several disadvantages. On the one hand it is prone to breakdowns, precisely because it works completely mechanically. When it is very dirty, the counterweight regulator may be activated perhaps too late (that is, only in case of very excessive speed).

Another disadvantage is the relatively high cost. Apart from the braking device itself, it is necessary a cable that runs through the entire gap, which must be guided from above and below and which must also be tensioned.

Another disadvantage is that this mechanical solution reacts exclusively by exceeding a predetermined speed. This is often not enough in today's high-speed elevators. This type of elevators travel with speeds of for example 10 m / s, and must be stopped by it in time before reaching the last floor (up and down). If the elevator car is in downward motion even on the first floor, then a speed of only 5 m / s remains high and should activate emergency braking.

To be able to activate an emergency braking more differently, an electronic solution is more appropriate. In this regard, corresponding proposals have already been made. From US 5020640, a braking device for an elevator was disclosed, in which the speed of the elevator car is determined by the propulsion wheel on which the carrier cable travels.

In general, a counterweight to the elevator car is provided in the elevators. Depending on the construction of this counterweight and other construction factors, it can sometimes be based on the basis that the elevator car can only reach a speed that is too high in the downward movement. However, sometimes too high speeds must also be available in the upward movement, for example, when the elevator car is empty and it is lighter than the counterweight, so that in case of failure of the elevator car control It is accelerated upwards by the counterweight.

From document US 5366045 A, which serves as a definition of the category of the present object, a braking or retaining device of the initially mentioned type was disclosed, in which the pressure body has two inclined circulation surfaces to which Two cuneiform braking bodies that engage on both sides of a guide rail are adjusted. In this case the retention member is formed by a solenoid, which retains the braking elements in a position against the force of springs, in which a space is maintained between their friction surfaces and the corresponding guide rail. If the solenoid is de-energized, the springs press the braking elements towards the space that narrows upwards, between the circulation surfaces of the pressure body and the guide rail, which results in a friction block between the braking elements and the guide rail and the clamping pressure of the braking elements continues to increase.

However, in the known case it happens that this increasing braking effect only occurs in a downward movement of the elevator car. In an upward movement, the friction block generated between the guide rail and the braking elements acts by reducing the braking force. This is advantageous in that it can therefore be lifted with a crank an elevator car braked to the floor immediately

higher. But it also has the disadvantage that during emergency travel, emergency braking cannot be achieved.

In the case of this known solution, there is also the problem that, particularly in the event of positional failures of the guide rails, it can happen that the braking elements engage only on one side to the guide rails, whereby a tilt can occur of the elevator car and as an additional consequence very important damage to the guide rails. This is because the magnitude of the increase in braking force depends on the braking force itself (i.e. friction). If the friction is lower on one side, the tightening pressure is also lower, so that the braking force is greatly reduced.

From EP 0 841 280 A1 a retained device with the space, groove and roller arrangement defining the present category is known. This retention device is, however, only capable of being activated in the upward movement of the elevator car. It also depends on a mechanical activation by means of a speed limiting cable or the like, that is, on an activation device that introduces the roller the first small section into the space between the guide rail and the pressure body.

Presentation of the invention

Technical task

Faced with this, it is the task of the invention to present a braking and retention device that can be omnidirectionally effective and can be activated electrically, but also guarantees effective safety in the event of a power failure, not eventually becoming inoperative. due to lack of current.

Technical solution

According to the invention this is achieved in a braking or retaining device of the type mentioned initially with the characterizing features of claim 1. A particular advantage of the measures according to the invention is that the solenoid works against the pretension of the spring and thereby guarantees the activation of the braking or retained device in case of lack of total current, so that nothing can happen in any way.

To minimize the risk of deterioration of the guide rails in the event of braking due to a breakdown, it is advantageous to provide the features of claim 2.

With these measures a compression load of the guide rails that could occur in the case of the union of two pressure bodies assigned to different guide rails on a rigid carrier can be avoided. In addition, such a braking device is also suitable for elevators whose elevator cars are guided only by one or two guide rails fixed to the same wall.

With the characteristics of claim 3, a weakening of the rigidity of one of the parts of the pressure body (corresponding to the direction of upward movement of the elevator car) is achieved, thereby reducing the clamping force of the body of braking in case of braking in the upward direction of the elevator car. Due to this, braking in the upward direction of travel is given a lower delay, so that a take-off of the floor of the elevator car by passengers can easily be avoided.

Brief description of the drawings

The invention is described in more detail below with the help of the drawings. They show: Fig. 1 a braking organ according to the invention schematically; Fig. 2 a braking or retaining device according to the invention schematically in a horizontal section; and Fig. 3 this braking or retaining device seen in the direction of arrow III of Fig. 2.

Best solution for the construction of the invention

As can be seen from Fig. 2, the guide rails 2 have a rail head 8 connected with a rail foot 7 by means of a core 6.

In a braking or retaining device according to the invention, a braking element is provided in the form of a roller 9, which is provided on its two front surfaces 10 (see Fig. 1) with flanges 11. The wrapping surface of the roller 9 it serves as a friction surface 12. For this purpose it is provided with a knurling or a friction lining. It is intended to fit the guide rail 2 (see Fig. 2).

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, where the two arms 16, 16 ’embrace the guide rail 2 at its free ends.

The pressure body 19 has on its arm 16 a space 20, in which the roller 9 is introduced. In this case the space 20 has a groove 21 that allows the friction surface 12 to be accommodated (see Fig. 1) of the roller 9.

The roller 9 is rotatably housed on an axis 22 (not shown in Fig. 2, see Fig. 3.), which passes through a hole 23 in the arm 16 and is housed in a support 25.

This support 25 is surrounded by a spring 28, which is configured as a pressure spring and which presses the roller 9 towards the guide rail 2. Against this spring 28 a solenoid (not shown) takes effect, which is controlled by a device speed monitor of the elevator car. In this case, the solenoid is de-energized when a speed of the elevator car is reached too high. In this way the spring 28

10 moves the support 25 and thereby the roller 9 against the guide rail 2, so that it fits with its friction surface 12 (see Fig. 1) to the guide rail 2 (see Fig. 3) and rotates .

The shaft 22 of the roller 9 can also be fixed to a conventional cable of a traditional speed limiter and be moved by it into the narrowing space 20. In this way this type of retention device is suitable to be activated electrically (through the de-energized solenoid) or mechanically (through

15 of the cable).

In a downward movement of the elevator car, the roller 9 rotates clockwise (in the case of observation according to Fig. 3). In this way the roller 9 rolls in the guide rail 2 and ascends upwards. Since the distance between the groove 21 and the guide rail 2 narrows in the upward direction, the roller is trapped between the groove 21 and the guide rail 2, thereby frictioning the groove 21 and thereby braking, so 20 that the elevator car not shown stops. In the final position the friction surface 12 (see Fig. 1) touches the groove 21 at point 41 (see Fig. 3), and at point 42 the flanges 11 of the roller 9 (see Fig. 1) touch the space 20 (see Fig. 3) next to the groove 21. At point 42 the depth of the groove 21 is correspondingly large, so that the friction surface 12 (see Fig. 1) does not touch the groove 21 at that point (see Fig. 3). In this way the movement path of the roller 9 is limited, without this having a

The influence on the braking force can be mentioned, given that the friction in the area of the flanges 11 (see Fig. 1) is relatively low (the flanges are smooth). With a corresponding configuration of the distance of the groove 21 (see Fig. 3) to the guide rail 2, the delays given can be correspondingly predetermined. Due to the rotating support 25 and due to the perforation 23 the roller 9 can move without obstacles along the space 20.

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

The space 20 (or the groove 21) has about half a depression 31 for the determination of the inactive rest position. The roller 9 is brought to this position by the energized solenoid. In this case there is a distance between the guide rail 2 and the roller 9.

In the embodiment shown in Fig. 3, a notch 32 is provided in the lower zone for reduction

35 of the stiffness of the pressure body 19. In this way, a correspondingly lower stiffness is achieved in the part of the pressure body 19 corresponding to an upward movement and thereby a lower tightening pressure of the roller 9, resulting in a delay minor in case of braking.

The latter can also occur by a correspondingly different construction of the course of the groove 21 above and below the depression 31.

Claims (3)

1. Braking or holding device for an elevator car, which is guided in a recess along vertical guide rails (2), where a braking element provided with a friction surface (12) is movably maintained in a pressure body (19) of the braking device placed in the elevator car and which can be placed from an inactive rest position determined by a retaining member in a guide rail (2), where the braking member is configured by a roller (9) whose axis runs normally in relation to the longitudinal direction of the guide rail (2) and whose wrapping surface is configured as a friction surface (12) and which is scrollable guided with 10 lowered flanges (11 ) in a space (20) of the pressure body (19) that runs parallel to the assigned guide rail (2), where the space (20) has a groove (21) for housing the friction surface (12) of the roller (9), d where the groove (21) has a distance that is reduced in relation to the guide rail (2) towards at least one end, so that the roller (9) adjusts in this position with its friction surface (12 ) on the one hand to the guide rail (2) and on the other hand to the groove (21) 15 (position 41) and the roller (9) also adjusts in this position with its flanges (11) to the space (20) next to the groove (21) (position 42), so that an additional displacement of the roller (9) is avoided, where the roller (9) is connected to the retention member that determines its inactive rest position, characterized by the fact that the space (20) and the groove (21) extend to both sides from a depression (31) that determines the inactive rest position, and the retention member has a 20 solenoid rotatably housed and the roller (9) is prestressed by a spring (28) against the guide rail (2) assigned, so that the spring (28) is configured as a compression spring and presses the roller (9) towards the guide rail (2), where the solenoid, which is controlled by a monitoring device for the speed of the elevator car acts against the spring (28) and the solenoid is de-energized when a too high speed is detected in the elevator car, whereby the 25 spring (28) moves a support (25) and with it the roller (9) against the guide rail (2), so that it fits with its friction surface (12) to the guide rail (2), puts it in rotation and moves in the guide rail. 2. A braking or retaining device according to claim 1, characterized in that the pressure body (19) is engaged behind the guide rail (2). 3. Braking or holding device according to claim 1 or 2, characterized in that the pressure body (19) has a notch in the area of the part of the space (20) (32) that runs perpendicular to the guide rail (2).