The invention relates to a method for regulating the brake(s) of an escalator or a
moving walkway.
For stopping the step or pallet band of an escalator or a moving walkway on tie
response of safety elements, substantially mechanically or electromechanicslly
actuated brakes, in particular shoe brakes, have been used so far. These
brakes are usually spring-loaded, the effect of the spring being eliminated by a
magnet coil, such that the brake remains opened in the operating state. Wr ile
stopping the escalator or moving walkway, the effect of the electromagnet is
eliminated and thereby the thus prevailing spring force is made use of. Usually
the braking area and the balance weight are located independently from esch
other, but normally they form a coherent system in the form of a brake dnm.
The balance weight serves for maintaining the brake path within ihe
predetermined limits. An essential criterion for dimensioning the balance wei ght
is the load caused by the number of passengers and for moving walkways i: is
essentially the length in connection with the passenger load thereon.
In case the emergency stopping device is actuated or safety switches and otner
safety means respond, the driving unit will be separated from the power sup Dly.
Simultaneously the brake will be applied.
It is a disadvantage of the known brake that the brake is partially applied in a
load dependent manner, that no equal brake paths can be obtained - since they
are dependent on the load -, and that under certain constructional conditions (for
instance excessive length of moving walkways) such big balance weights are
required, that one reaches technical limits regarding the accommodation.
Furthermore, a higher wear of the brake linings can be expected, whereby a
continuous adjustment of the mechanical brakes becomes necessary duo to
safety reasons.
From DE-A-35 09 207 a method and an apparatus for stopping slid ng
passenger transport installations, for instance an escalator, are known, in wh ch
the movement of the escalator is stopped in a controlled way, essentially
independently from the load and the moving direction of the escalator. The
deceleration is monitored and controlled continuously by a signal, which is
provided by a speed converter, such as for instance a speedometer generator.
Direct current is supplied to the windings of an alternating current motor serv ng
as drive motor, the electro-dynamic braking effect generated in the motor
causing predetermined deceleration behaviour of the movement of the escalator.
In the braking case, the windings of the drive motor are preferably supplied with
a pulsating d.c. Voltage, which is formed and controlled by means of a thyristor
circuit which is controlled by electronic elements, and which provides a
reference speed value for the escalator on the basis of the speed of he
escalator provided by a speed converter, such as for instance a speedometer.
Recently, frequency converters have been used for braking passenger transport
installations, in particular escalators and moving walkways, so that, in certain
circumstances, mechanical brakes as operational brakes are no more requirec to
a large extent. Herein however, the frequency converters are elements, wh ch
cause higher costs and may thus not be desired by clients in certain
circumstances.
It is an object of the invention to improve a method for regulating the brake(s] of
an escalator or a moving walkway, such that a control schema is formed, wh ch
is independent from frequency converters, and which can also be integrated into
existing installations, if necessary, without requiring particular assembly end
expenditure.
To achieve this object, the present invention provides a method for regulating tho
brake(s) of an escalator or moving walkway by supplying actual values to at leas:
one regulator, which contains at least one theoretical value, the regulator
performing a comparison between the theoretical and actual values and
controlling at least one brake magnet using this value, characterised in that
theoretical values in the form of several temporary deceleration values are stored
in the regulator in theoretical value fields or theoretical value zones; and tho
regulator intermittently performs the comparison between the theoretical and
actual values for regulating the brake(s) independently from the load, whereb/
the brake magnet acts on the brake(s), such that a predeterminable linear
braking deceleration is achieved.
The regulator may be intermittently or continuously supplied with an actual value
(I) in the form of speed values of the drive(s) of the passenger transpoit
installation, which have been determined by initiators or other sensors.
The regulation of brakes can be performed according to Fuzzy-logic.
The brake magnet is preferably controlled independently from the power supp y
of the drive.
A braking device operating according to the method, of the invention comprises at east
ana, in particular spring-leaded braka, such as for instance a shoe brake, which can be
controlled by at least one brake magnet, which can be controlled by at least one
regulator, which performs an intermittent comparison between theoretical and actual
values.
Thus, the objeclpfjhe invention provides a preferably closed control circuit, whicli can
also be retrofitted in existing installations, and which can be integrated into new
installations, on the one hand, and existing installations, on the other hand, without
great expenditure and assembly.
In comparison to the state of the art, the method according to the invention as we ill as
the braking device according to the invention make ft possible to brake the step cr f altet
band of escalators and moving walkways in a load independent manner, which
essentially has the following advantages:
- always equal brake paths, since independent from the load;
- low wear of the operational brake, in particular of the brake shoes of a shoe
brake;
- at least partial reduction of the balance weight;
- at least partially smaller dimensioning of the drive motor.
Using the method according to the invention respectively the braking device operating
according to it, the speed of the escalator or moving walkway can be decreased in a
defined way to the value 0 m/s, with substantially uniform deceleration. At the moment
of response of for instance a safety element, a brake ramp is activated, whereby a
uniform braking with linear deceleration can be achieved, while observing the brake
path defined in the corresponding regulations. The regulator contains deceleration
values as theoretical value(s), which are intermittently compared to preferably soeed
values of ths drive motor of the escalator or moving walkway.
According to a further aspect of the invention the brake magnet can be contiolled
independently from the power supply of the drive motor. This requires a slightly hgher
effort, since an independent power supply has to be provided; but for certain
applications, in particular regarding technical safety aspects, this way of use are
considered as a further alternative for improving the object of the invention in a
useful way.
The object of the invention can be applied to all kinds of brakes used with
escalators and moving walkways. But it shall be preferably used with sioe
brakes provided with spring-loaded brake levers.
The object of the invention is represented in the accompanying drawing by
means of an exemplary embodiment and described as follows:
Figure 1 shows a partial representation of the braking device of, for instcince,
an escalator;
Figure 2 shows a braking device according to figure 1, including an acti al
speed value determination;
Figure 3 is a functional diagram of the improved method according to the
invention for regulating the braking device according to figures 1
and 2.
Figure 1 is a partial representation of brake 1 of an escalator (not shown). One
can see a brake drum 2, a brake lever 3, a spring packet 4, a holding device 5 as
well as a brake magnet 6, which is driven with direct current in this example.
Figure 2 shows the same elements as already described. Furthermore, cne can
seen the following components: housing 7 of drive motor 8 as well as sensors 9
(for instance proximity switch initiators) for determining the speed of drivo motor
The overspeed and low speed of drive 8, which is formed by an electromotor, is' ,
detected by initiators 9 and provided to a motor guard (not shown). In the rormal
state of the escalator, shoe brake 10 situated at brake lever 3 is released, i.e. It
does not rest upon drive motor 8 formed by a brake drum. In case of swi :ching
off the drive, spring 4 will press brake lever 3 on the brake drum, which forms
drive motor 8, and thus produce a braking moment. Herein, brake lever 3 is
pressed onto the brake drum and stops the step band.
Such mechanically acting brake devices 1 are state of the art, but every other kind of
brake, eventually net cf the mechanical type, can also be used.
Figure _3_ shows a schematic diagram of a regulating scheme for braking de/ice 1
according to figures 1 and 2. Reference numeral 11 designates the power supply.
Reference numeral 12 refers to a regulator and reference numeral 13 to a brake
magnet. Electromotor 8 as well as brake lever 3 and speed sensors 9 are indicated.
Preferably several predetermined theoretical values regarding potential decele-ation
ramps are stored in regulator 12, In this example, speed sensors 9 intermittently
determine the respective speed of drive motor 8 and provide it as an actual value to
regulator 12. Regulator 12 performs an intermittent comparison between the theonrtical
and actual values, the results of which are transmitted to brake magnet 13 in form of
setting values, so that this one can in turn act on brake lever 3 in a regulating way.
As soon as the escalator is no more driven, brake lever 3 according to the
representation of figure 1 and 2 will abruptly become active via brake magnet 6, wtiich
is no more supplied with energy, since then the force of spring 4 will work. This abixipt
stopping can cause problems with regard to a jerkily deceleration of the step band of the
escalator, which can, in certain circumstances, cause risks of injury, unless appropriate
measures have been taken.
Due to the regulation using the comparison between theoretical and actual values, this ,
operation is now bridged by controlling brake magnet 13 in a defined way, should tie
occasion arise, also during a power cut, so that a substantially linear braking according
to predetermined criteria (brake ramp) is possible.
It is also possible, that several theoretical values (S) are stored in the regulator n
theoretical value fields or theoretical value zones in form of brake ramps, which enable
a so called fu2zy-logjc-drcuit, wherein regulator 12 then determines the best possible
brake regulation or brake ramp as a function of the supplied actual values (I).
WE CLAIM:
1. An improved method for regulating the brake(s) of an escalator or moving
walkway by supplying actual values (I) to at least one regulator (12), which
contains at least one theoretical value (S), the regulator (12) performing a
comparison between the theoretical and actual values and controlling at east
one brake magnet (13) using this value, characterised in that theoretical ve lues
(S) in the form of several temporary deceleration values are stored in the
regulator (12) in theoretical value fields or theoretical value zones; and the
regulator (12) intermittently performs the comparison between the theoretical and
actual values for regulating the brake(s) (1) independently from the load,
whereby the brake magnet acts on the brake(s), such that a predeterminable
linear braking deceleration is achieved.
2. Improved method as claimed in claim 1 wherein the regulator (12) is
intermittently or continuously supplied with an actual value (I) in the forrr of
speed values of the drive(s) (8) of the passenger transport installation, which
have been determined by initiators or other sensors (9).
3. Improved method as claimed in claim 1 or 2, wherein the regulation of
the brakes (1) is performed according to Fuzzy-logic.
4. Improved method as claimed in any one of claims 1 to 3, wherein ihe
brake magnet (13) is controlled independently from the power supply of Ihe
drive (8).

The invention relates to a method for regulating the brake(s) of an
escalator or moving walkway, independently of the load. According to the invention,
actual values (I) are supplied to at least one regulator which contains at least one
theoretical value (S), the regulator intermittently performs a comparison between the
theoretical and actual values and controls at least one brake magnet using these values.
The brake magnet or magnets in turn regulate(s) the brake(s) in such a way,
that a predeterminable linear braking deceleration can be achieved, whereby theoretical
values (S), in particular, in the form of several temporary deceleration values are
stored in the regulator in theoretical value fields or theoretical value zones.