EP1841679B1 - Emergency braking device for a lift cabin - Google Patents

Description

Technical environment

The invention relates to an emergency brake device for an elevator car according to the preamble of claim 1.

Lifts are provided with braking or catching devices which serve to lift the elevator car in the event of an excessively high speed, e.g. in the event of control errors or in the event of a break in the ropeway, decelerate.

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 generic US 5020640 A a braking device for a Aufzung was known in which the speed of the elevator car by means of of the drive wheel is determined, on which the support member rolls.

In this known device there is the problem that in the case of a cable break the device fails. Another disadvantage is that (at least) an additional line from the elevator car to the engine room is required to transmit the rotational speed of the drive wheel to the elevator car.

By the US 5366045 Aa storage and retrieval unit has been known in which a support arm is held on a mast raised and lowered and in which an appealing at a high speed of the support arm braking device is provided. In this case, a connected to a speedometer wheel is provided, which rests against the mast. This speedometer is connected to a high speed detection device which activates a braking device.

This solution is not safe enough for a lift. It is easily possible that oil or grease comes on the wheel, so that this slips on the mast and thus in the case of a rope break the speedometer reports no excessive speed.

By the US Pat. No. 6,161,653 is a lift with an electrically releasable braking or catching known. For the electrical release, any speed detector of known design should be used, which will not be described further.

Finally, out of the JP-A-01317977 a lift is known, which uses a detector system consisting of two rolling on different, opposite guide rails wheels, each driving its own detector. The solution calculates that, due to vibrations, tolerances or the like, temporarily one of the two wheels has no contact with the guide rail and therefore does not roll at a speed that is truly representative of the speed of the elevator car. This problem is corrected on the signal side by continuously evaluating the signals and using only the higher, higher speed signal as a representative quantity.

Presentation of the invention Technical task

The aim of the invention is to avoid these disadvantages, to propose an emergency braking device of the type mentioned, in which a reliable detection of the speed of the elevator car is ensured, in particular unreliability in the area of the speed signal generating wheels should be eliminated as much as possible and in the the entire emergency brake device can be accommodated in the area of the elevator car so that no connection to the engine room, for example, is necessary.

Technical solution

According to the invention this is achieved in an emergency braking device of the type mentioned by the characterizing features of claim 1.

The proposed measures ensure that on the one hand, even in the case of a rope break, the speed of the elevator car can be detected, as their detection is independent of the supporting cable. In addition, results from the arrangement of two wheels on two sides of the same guide rail not only the advantage that the speeds of the two wheels can be compared with each other and thus any slippage of one of the wheels can be detected and reports a fault and the elevator after Termination of the trip can be blocked. Rather, it is very largely avoided in this way from the outset that one of the wheels has poor frictional contact and thus provides an unusable signal. Because the fact that both wheels scanned one and the same guide rail, it is impossible that temporarily one of the wheels, due to tolerances in the distance of the guide rails from each other, loses its clean frictional engagement. Also, vibrations or similar disturbances on the part of the elevator car can influence the wheels here only in very extreme cases, since the wheels face each other on different sides of the same guide rail and thus, so to speak, clamp the guide rail between them. It should be noted that an emergency brake is of course already triggered when only one wheel reports too high a speed.

It is useful if the arrangement of the two wheels takes place according to claim 2. Due to the bias of the rocker by the spring, which may also be relatively weak, a relatively high contact pressure of the two wheels is achieved. This is due to the fact that the distance between the two rollers can be selected only slightly larger than the width of the head of the guide rail and the spring can attack at a large distance from the pivot point of the rocker, which is conveniently located between the two wheels, resulting in a correspondingly high contact pressure of the rollers on the guide rail due to the moment equilibrium

Due to the features of claim 3, there is the advantage that slipping is practically impossible, since, if only one of the wheels interconnected via the shaft slips, the other drives the shaft, where the friction sufficient for a rolling of the wheel. As a result, any slippage of one of these wheels does not affect the detection of the speed of the elevator car.

Due to the features of claim 4, there is the advantage that the shaft connecting two held in different rockers wheels can activate the brake device with appropriate control of the actuator via the pipe. So this is a kind of power assistance that gets the energy out of the roles. In this case, the actuator may be formed by a solenoid, which in the case of triggering the braking device, i. at too high speed of the elevator car, is de-energized, so that the spring moves the friction wheel in a position in which it is in contact with the rotatably connected to the shaft friction wheel. Due to the eccentric mounting of a friction wheel it comes to jamming of the two friction wheels, whereby the U-profile is coupled to the shaft and is taken away by this. This leads to the rotation of the tube and the activation of the braking device.

A disadvantage of this solution, however, that the length of the shafts and the tube to the width of the elevator car (or the distance between the guide rails) must be adjusted.

If you want to avoid this disadvantage, you can provide the features of claim 5. In this case, separate, each acting on a guide rail brakes may be provided, which are controlled by the actuators, which in turn are controlled jointly.

Short description of drawings

The invention will now be explained in more detail with reference to the drawing. Showing: Fig. 1 schematically an axonometric view of a detector according to the invention for detecting the speed of an elevator car; Fig. 2 the detector after Fig. 1 schematic in view; Fig. 3 schematically a detector after Fig. 1 in conjunction with an actuator for a braking device in axonometric representation; Fig. 4 the driving device of the Fig. 3 in view; Fig. 5 schematically a triggering device for a braking device; and Fig. 6 schematically a further embodiment of a triggering device for a braking device.

The best way to exploit the invention

How out Fig. 1 can be seen, the guide rails 2 a connected via a web 6 with a rail 7 rail head 8.

On both side surfaces of the rail head 8 are wheels 9, which in a rocker 10 (see also Fig. 2 ) and rotatably connected to a detector 11 are rotatably held. These detectors 11 are connected via signal lines 12 to a device 13 for detecting a too high speed.

The rocker 10 is as out Fig. 2 can be seen, held pivotably about an axis 14 between the two wheels 9 and acted upon by a spring 15 which is supported on an abutment, not shown, and for a rotation of the rocker 10 and thus to a contact pressure of the wheels 9 on the two side surfaces sixteenth of the rail head 8 provides. Since the clear distance between the two wheels 9 is only slightly smaller than the width of the rail head 8 and the spring 15 acts at a greater distance from the axis 14 of the rocker 10 at this, there is a corresponding leverage, and it can also with relative weak springs 15 a high contact pressure of the wheels 9 can be achieved.

In the embodiment of the Fig. 3 lie on each of the two guide rails 2 per two wheels 9, which are held in rockers 10. In each case, two adjacent to different guide rails 2 wheels 9 via a respective shaft 17, 17 'rotatably connected to each other, which is in each case surrounded by a detector 11. In this case, these detectors 11, for example, with each revolution of the shaft 17 from a pulse.

The shaft 17 'is surrounded by a tube 18 which is subdivided into two sub-pipes 18', 18 ", these two sub-pipes 18 ', 18" being connected to one another via a U-profile 19. In this case, a detector 11 is seated between the two legs of the U-profile 19th

Like from the Fig. 4 can be seen in detail, between the legs of the U-section 19, a friction wheel 22 rotatably mounted on the shaft 17 'is arranged. This cooperates with another friction wheel 20 which is immovable in the axial direction, however is rotatably supported on a push rod 21. (Alternatively, of course, the push rod 21 may be rotatable, then the friction wheel 20 may be fixedly mounted on the push rod 21.)

This push rod 21 passes through the two legs of the U-profile 19 and is held in a solenoid 23, which via control lines 24 to the device 13 (see Fig. 3 ) and is controlled by this. Furthermore acts on the push rod 21 (see Fig. 4 ) a spring 25 (which is designed as a compression spring), which is supported on the outside of the one leg of the U-profile 19 and on a shoulder 26 of the push rod 21.

In the illustrated, the normal operation corresponding position of the friction wheel 20, the solenoid 23 is energized and keeps the friction wheel 20 against the force of the spring 25 out of engagement with the friction wheel 22. This leaves the tube 18 in its position.

However, when the solenoid 23 is de-energized, e.g. due to the detection of excessive speed of the elevator car (or even in case of failure of the power supply and the emergency power supply), the spring 25 causes a displacement of the push rod 21 to the right, whereby the friction wheel 20 comes into contact with the friction wheel 22 and from this is set in rotation. Since the friction wheel 20 is held eccentrically, there is a jamming of the friction wheel 20, since the distance between the shaft 17 'and the push rod 21 is designed for the smallest distance between the lateral surface of the friction wheel 20 and its eccentric axis of rotation. As a result, the U-profile 19 is taken and therefore the tube 18 is rotated.

Since the pipe 18 and the sub-pipes 18 'and 18 "with levers 27 (see Fig. 3 ), which in turn are connected to links 28, which act on a braking device, not shown, which engage the guide rails 2, in this case the braking device is activated and the elevator car braked.

In the Fig. 5 a further embodiment of a triggering device for a braking device is shown schematically. In this case, a shaft 30 is provided, which is rigidly connected to a projection 31 which cooperates with an electromagnet 23 'and acts on the return spring 32. At the two ends of the shaft 30 is connected to levers 27 which are connected to links 28 which act on the brake device, not shown.

As long as the solenoid is energized, the shaft 30 and thus the levers 27 remain in a position in which the braking device is not activated and remains inoperative. If the solenoid 23 'de-energized, the return spring 32 causes a rotation of the shaft 30 and thus also the lever 27, whereby subsequently the braking device is activated and the elevator car is stopped.

In the embodiment of the Fig. 6 are attached to the one leg 40 of a pivotable about the axes 42 angle lever 41, a lug 31 which is connected to a Electromagnet 23 'cooperates and on which a return spring 32 engages. In this case, the electromagnet 23 'and the return spring 32 act at a standard distance from the axis 42 of the angle lever 41 on the projection 31 a. This results in a corresponding rotation of the angle lever when the solenoid 23 'is de-energized, and the second leg 43 of the angle lever 41 activates the brake device, not shown. In the embodiment according to the Fig. 6 Arranged in the region of each guide rail 2 angle lever 41, wherein the two electromagnets 23 'are driven together.

Claims (5)

1. Emergency braking device for a lift cabin running in a shaft on guide rails (2) and can be lifted and lowered by means of a cable, wherein a detector (11) acquiring the speed of the cabin and comprising a device (13) for detecting an excessive speed is provided, which electrically controls a braking device, characterised in that two wheels (9) are provided for determining the speed, which rest against a guide rail (2) in such a way that one wheel rests against the one side of the rail head (8) of the guide rail (2) and the other wheel rests against the other side of the rail head (8) of the guide rail (2) and the rate of rotation or rotational speed of each wheel (9) is acquired by detectors (11) independently from each other, and that the device (13) triggers the emergency braking once at least one of the detectors (11) indicates an excessive speed.
2. Emergency braking device according to claim 1, characterised in that the two wheels (9) are mounted on a pivotably supported rocker bar (10) on both sides of a guide rail (2), the rocker bar (10) being biased by a spring (15).
3. Device according to claim 2, characterised in that two wheels (9) mounted in rocker bars (10), respectively, rest against two opposite guide rails (2), wherein two wheels (9) resting against different guide rails (2), respectively, are interconnected via shafts (17, 17').
4. Device according to claim 3, characterised in that one of the two shafts (17') is guided in a pipe (18) connected to the braking device, wherein this pipe (18) is interrupted and the two ends of the partial pipes (18', 18") of the pipe (18) that face each other are non-rotatably interconnected via a U-profile (19), in whose legs a push rod (21) is mounted that is loaded by a spring (25) and can be displaced against the action of the spring (25) by an actuating organ (solenoid 23) connected to the device (13) for controlling the braking device, whereby a friction wheel (20), which is eccentrically mounted on the push rod (21) and retained in an axially non-displaceable manner, can be brought into contact with another friction wheel (22) seated on the shaft (17').
5. Device according to any one of the claims 1 to 3, characterised in that the braking devices for the two guide rails are controlled by separate controlling devices, with the actuating organs (electromagnets 23') of the controlling devices being jointly controlled by the device (13) for controlling the braking device.

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