EP0307557B1 - Switch-off device for an escalator - Google Patents

Abstract

A pair of light barriers are mounted on a pair of spaced apart balustrade sockets located on opposite sides of an endless step conveyor-type escalator. The light barriers are positioned at the transition of upper and lower transisition arches to an inclined run of the conveyor. The light barriers each include a transmitter and receiver for emitting and receiving a light beam transversely to the direction of travel of the conveyor. The light beam is interrupted by side shields on the conveyor steps. An opening is formed adjacent a leading edge of each side shield and one or more openings are formed adjacent a trailing edge of each side shield. The trailing edge openings are formed as oblong holes each with a longitudinal axis extending with respect to the tread of the step at the same angle as the inclination of the inclined run of the escalator with respect to the horizontal. The oblong holes are formed at different angles corresponding to typical angles and inclination such that the side shields can be used with different standard escalator installations.

Description

The invention relates to a switch-off device for an escalator for initiating the stoppage of an endless, consisting of several steps and two link chains arranged laterally next to the steps, guided between two balustrade sockets, a walkable lead with two horizontal runs, an inclined run and two transition arches, which step immediately comes into effect when it detects a malfunction of the moving step belt or a defect in the step belt.

For safety reasons and in order to comply with the relevant regulations, each escalator must have a number of monitoring and shutdown devices. For example, the backward running of an upward escalator must be prevented, or a downward escalator must not exceed the normal speed by more than 20% and it must be stopped automatically when this excess speed is reached. An escalator must also be switched off when a step descends, i.e. if, for whatever reason, the step surface of a step would no longer be guided through the comb in a perfectly horizontal position.

DE-C-628503 has disclosed such a device for switching off an escalator, which responds by approximately 20% when the normal speed selected between two predetermined step belt speeds is exceeded. The step belt is moved by a DC motor, which drives the main shaft via a reduction gear and a chain gear. A governor working according to the centrifugal force system is driven by a chain from the main shaft and monitors the driving speeds, whereby an electromagnet adjusts a regulator sleeve of the regulator in accordance with the selected normal driving speed, so that the regulator only responds at both adjustable driving speeds and stops the escalator when a percentage of approximately the same overspeed occurs. For the selection of the speed and the direction of travel, a selector switch for a small and a high speed and a direction switch are accommodated in an apparatus cabinet.

With DE-A-3319831 a further device for switching off escalators or moving walks has become known, in which a switching means, which can be actuated by lowering an escalator step or a step plate and is arranged under the step bodies in the area of the accessible lead, initiates the shutdown of the conveyor device. A spring-braced or spring-supported copper wire insulated from the mass of the conveyor serves as switching means. One pole of a DC power source is connected to the copper wire, the other to the ground of the conveyor. As soon as a step body lowers, for example when the rubber bandage of a roller of a step body loaded by at least one passenger falls off, the step body touches the copper wire and thereby closes the circuit of the direct current source. The conveyor belt drive is switched off with the help of a relay.

Another device for switching off an escalator has become known with EP-B-082074, in which each individual step is monitored with the aid of at least one distance sensor arranged in the return of the step band, in conjunction with a logic circuit. In the absence of a step, the logic circuit triggers a false signal at the command of the distance sensor and causes the escalator to be shut down immediately via a relay.

Another device for switching off an escalator has become known from US-A-4,151,381, in which the escalator is automatically stopped as soon as the step belt switched for upward movement moves unintentionally in the downward direction. An idle roller driven by the main drive shaft of the transmission housing, with a circumferential groove, is in frictional connection with an actuating rod which rests on the circumferential groove and is displaceably mounted in the axial direction and cooperates with a limit switch. When the step belt runs upwards, the idler roller is driven in a counterclockwise direction, the actuating rod being pulled away from the switching lever of the limit switch due to the friction and abutting against the rod guide by means of a stop disk. If the step belt rotates unintentionally in the downward direction, the actuating rod is pushed against the switching lever of the limit switch by the friction of the idler roller driven in a clockwise direction, the limit switch being actuated and the escalator being stopped.

All of the devices shown for switching off an escalator have the disadvantage that a separate device is required for each individual monitoring task, and that each individual device is a relatively complex device.

The invention is therefore based on the object of proposing a device for switching off escalators, by means of which a plurality of independent safety devices can be monitored and by means of which the escalator is switched off when one of the monitored safety devices responds.

The advantages achieved by the invention can essentially be seen in the fact that a single device for switching off an escalator is sufficient to monitor several safety devices at the same time. A Another advantage is that the exact same device can be used for different escalator inclinations, such as 35 °, 30 °, 27.3 °, 24.5 °.

On the accompanying drawings, an embodiment of the invention is shown, which is explained in more detail below.

Fig. 1

eine Seitenansicht des in vertikaler Richtung geschnittenen Stufenband-Vorlaufes;

Fig. 2

einen Querschnitt durch das Stufenband, gemäss der Schnittlinie A-A der Fig. 1;

Fig. 3

eine Seitenansicht einer anmeldungsgemässen Stufe einer 30°-Fahrtreppe mit einem Lochmuster für verschiedene Fahrtreppentypen;

Fig. 4

eine Seitenansicht einer abgesenkten Stufe einer 30°-Fahrtreppe;

Fig. 5

Hell-Dunkel Intervalle für diverse Fahrtreppentypen bei Normalbetrieb und bei fehlerhaftem Betrieb bei einem bestimmten Fahrtreppentyp.

Show it:

Fig. 1

a side view of the step belt feed cut in the vertical direction;

Fig. 2

a cross section through the step band, along the section line AA of Fig. 1;

Fig. 3

a side view of a step according to the application of a 30 ° escalator with a hole pattern for different escalator types;

Fig. 4

a side view of a lowered step of a 30 ° escalator;

Fig. 5

Light-dark intervals for various types of escalators during normal operation and in the event of incorrect operation with a specific type of escalator.

1 and 2, a balustrade of an escalator arranged on both sides of a step belt 3 is designated by the number 1. The step belt 3 consists of a number of steps 4, which are fastened between two endlessly rotating link chains 5 to each of the step axes 13 connecting the two link chains 5, and forms a walk-in flow and a return. The advance of the step belt 3 is in turn divided into a lower horizontal run 3.1, an upper horizontal run 3.2, an oblique run 3.3 and a lower and an upper transition curve 3.4, 3.5. Each stage 4 always has a step 3 that can be entered in advance horizontally guided tread surface 4.1, a riser 4.2, two side plates 4.3, two chain rollers 6 mounted on the step axis 13 between the plates of the plate chain 5 and two drag rollers 7. The chain rollers 6 are placed on a chain guide 14, the drag rollers 7 on a roller guide 15. The lead of the step belt 3 is guided between two balustrade bases 2 arranged below the balustrades 1. At the upper end of the skew 3.3 of the step belt 3, before the transition to the upper transition arch 3.5, a light barrier 8 with a transmitter 10, a receiver or reflector 11 and a beam transversely to the direction of travel of the step belt 3 is emitted on both sides of the balustrade base 2 Beam of light 12 installed. Likewise, a light barrier 9 with a transmitter 10, a receiver or reflector 11 and a light beam 12 is provided on both sides of the balustrade base 2 at the lower end of the skew 3.3 of the step belt 3 before the transition to the lower transition arch 3.4. The position of the light barrier 8, 9 is selected such that the light beam 12 is directed directly over the link plates of the link chain 5 transversely to the step belt 3 from one balustrade base 2 to the other and interrupted by each step 4 between the bearings of the chain rollers 6 and the riser 4.2 is, while it can be received between the riser and the bearings of the chain rollers 6 of the adjacent stage 4 unhindered by the receiver 11 of the light barrier 8, 9.

α =

24,5°

β =

27,3°

γ =

30°

δ =

35°

3 and 4, 4 denotes the step which can be used for all normalized stair inclinations. Each step is composed of the step surface 4.1, the riser 4.2 and the two side plates 4.3 and is connected by a step axis 13 to the two link chains 5 arranged laterally next to the steps 4. Two chain rollers 6 and two drag rollers 7, which are mounted on the step axis 13 between the link plates of the link chains 5, and two drag rollers 7 each carry 4 and lie on the chain guide 14 and the roller guide 15 on. The light barriers 8, 9 are permanently installed in the balustrade base 2 arranged next to the steps 4. Various cutouts are provided in both side plates 4.3 of the steps 4, which allow the light beam 12 to pass freely when the step belt passes the light barrier 8, 9 with the cutout corresponding to the inclination of the stairs; a recess 4.4 in the immediate vicinity of the step axis 13 for all escalator types, an elongated hole 4.5 for a 30 ° escalator, an elongated hole 4.6 for a 27.3 ° escalator and an elongated hole 4.7 for a 24.5 ° escalator. There is no slot for the 35 ° escalator. The central axes of the elongated holes 4.5, 4.6, 4.7 or a reinforcing rib 4.8 in the side plates 4.3 have the same angle of inclination α β γ δ to the step surface 4.1 of step 4 as the corresponding angle of inclination 3.3 of the step belt 3 to the horizontal.

α =

24.5 °

β =

27.3 °

γ =

30 °

δ =

35 °

e)

bei abgesenkter Stufe,

f)

bei fehlender Stufe,

g)

bei einem ungewollten Rücklauf und

h)

bei ca. 20% Übergeschwindigkeit bei gewolltem Abwärtsbetrieb.

Thus, the central axes of the elongated holes 4.5, 4.6, 4.7 in the skew 3.3 of the step belt 3 always run parallel to the respective chain guides 14 or roller guides 15 and coincide with the central axis of the light beam 12 of the light barriers 8, 9 in normal operation. With the exception of the 35 ° staircase, separate elongated holes are provided for each possible escalator inclination, which are staggered and partially have a different length. This prevents a correct hole pattern from being simulated when the step is lowered. In Fig. 3 for a 30 ° escalator during normal operation, the light impulses which occur when the step belt 3 drives past the light beam 12 of the light barriers 8, 9 are indicated by a double hatched path 20, 21, 22. In Fig. 4, the resulting light pulses when driving past one lowered level 4 also indicated with double hatched paths 20, 21, 23. 5 a), b), c) and d) each show the light-dark intervals of an escalator with 24.5 °, with 27.3 °, with 35 ° and with 30 ° inclination in each case with normal , upward escalator operation. 5 e), f), g) and h) show the light-dark intervals for faulty escalator operation, for example, for each 30 ° escalator

e)

with the step down,

f)

if there is no level,

G)

in the event of an unwanted return and

H)

at approx. 20% overspeed if intentional downward operation

The exactly same light-dark intervals according to FIG. 5 g) also apply to normal operation in the case of an intentionally downward escalator.

The device described above works as follows: The light barriers 8, 9 installed in the skew 3.3 of the step belt 3 in front of the upper transition arch 3.5 or in front of the lower transition arch 3.4 in the balustrade bases 2 are monitored by a known electronic evaluation circuit. When the step belt 3 drives past the upper light barrier 8 for the upward escalator, or the lower light barrier 9 for the downward escalator, the periodically received light-thinking intervals with a light-dark pattern stored for the corresponding normal operation compared and evaluated. If there is any change in the intervals or the pattern, e.g. at an overspeed, at an underspeed, due to a lowered step, due to a missing step or when the direction of travel is reversed, the escalator is switched off immediately and stopped by the normal service brake. The distance between the light barriers and the tip of the comb is selected so that it is greater than the distance traveled, for example one of the Device for switching off an escalator as a defective step until it comes to a standstill, or an escalator running at approx. 20% overspeed from the moment of the detected overspeed until the escalator comes to a complete standstill.

It is easily conceivable to monitor further safety devices on an escalator with the described device for switching off an escalator and to stop the escalator in the event of danger.

Claims (3)

1. Shut-off device for an escalator for the initiation of the stoppage of an endless stair belt (3), which consists of several steps (4) and two sprocket chains (5) arranged laterally beside the steps (4), is guided between two balustrade pedestals (2) and which displays a treadable forward run with two horizontal courses (3.1, 3.2), an inclined run (3.3) and two transitional arcs (3.4, 3.5), which device comes into effect at once when it ascertains a faulty behaviour of the moved stair belt (3) or a defect at the stair belt (3), characterised thereby, that a light barrier (8, 9), which emits and receives a light beam (12) transversely to the direction of travel of the stair belt (3) and is combined with an electronic evaluating circuit, is fixedly arranged at the balustrade pedestals (2) of the escalator at each transition of the lower and the upper transitional arc (3.4, 3.5) to the inclined run (3.3) of the stair belt (3), above the sprocket chains (5) and below the treadable tread surfaces (4.1) of the steps (4), and that at least one recess (4.4, 4.5, 4.6, 4.7), which is passable by the light beam (12) of the light barrier (8, 9) which moving past, is provided in the side plates (4.3) of each step (4).

2. Shut-off device according to claim 1, characterised thereby, that at least one recess (4.5, 4.6, 4.7) in the side plates (4.3) is an elongate hole, wherein its longitudinal axis displays the same angle (α, β, γ) relative to the tread surface (4.1) of the step (4) as the angle of inclination of the inclined run (3.3) of the associated escalator to the horizontal.

3. Shut-off device according to claim 2, characterised thereby, that elongates holes (4.5, 4.6,4.7) with the respectively associated angle of inclination of their longitudinal axes relative to the tread surface (4.1) of the step (4) are arranged in the side plates (4.3) of the steps (4) for more than one inclination of the escalator, wherein the elonate holes display a different length and are arranged to be displaced on relative to the other.

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