Conveyors: power-driven – Conveyor or accessory therefor specialized to convey people – By stairway having steps forming an endless member
Reexamination Certificate
1998-11-03
2001-03-13
Hess, Douglas (Department: 3652)
Conveyors: power-driven
Conveyor or accessory therefor specialized to convey people
By stairway having steps forming an endless member
C331S143000
Reexamination Certificate
active
06199678
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a hand rail driving apparatus of an escalator which drives a hand rail the same direction as steps which move passengers.
2. Description of the Prior Art
The escalator generally includes a driving motor
4
, a reducing drive
5
for reducing a turning effect of the motor, a driving chain
6
for transmitting the turning effect of the reducing drive to a driving sprocket
7
, and a driving wheel
8
positioned in an upper portion of a machine room
3
, as shown in FIG.
1
.
Supporting balustrades
2
and the hand rails
1
are mounted on both sides of the escalator for the sake of passengers. Steps
9
, on which the passengers board, are fixed in a step chain
10
. The steps move along guide rails together with the step chain while being supported by four step rollers, not shown in the figure.
In addition, a driven wheel
11
, to which a chain tension device having a tension spring is attached, is mounted in a lower portion of the machine room for preventing deflection of the step chain
10
.
Reference number
12
indicates a driving axis for connecting the driving wheels
8
on both side of the escalator.
FIG. 2A
to
2
C depict several examples of the conventional hand rail driving apparatus.
FIG. 2A
shows a hand rail driving apparatus using pressure of a flat belt. A hand rail driving pulley
13
is connected with use of a driving chain
14
to the driving wheel
8
which moves the steps. The hand rail driving apparatus drives the hand rail
1
by exerting pressure of the flat belt
15
on a contacting point with the hand rail of the hand rail driving pulley
13
.
FIG. 2B
depicts another hand rail driving apparatus using tension. In that apparatus, the hand rail driving pulley
13
is also connected with use of a driving chain
14
to the driving wheel
8
which moves the steps. The hand rail driving apparatus includes a tension roller
19
in the driving chain
14
. The apparatus controls tension of the driving chain, thus driving the hand rail.
In the apparatus using the pressure of the flat belt or the tension as described above, the hand rail driving pulley
13
is connected to the driving wheel
8
through the driving chain
14
, thus moving the hand rail
1
in the same direction and at the same speed as the step
9
. In the hand rail driving pulley
13
used in these types of apparatus, a frictional elastic body
16
which is made of rubber or urethane is provided by surface treatment, thus driving the hand rail with use of tension and friction of the flat belt
15
, as shown in
FIG. 3A and 3B
.
FIG. 2C
shows another conventional hand rail driving apparatus using contacting pressure of a roller. In that apparatus, the driving chain
14
transmits power of the driving wheel
8
to tension rollers
17
. A roller driving device
18
is rotated by the tension rollers
17
, thus driving the hand rails
1
by exerting a constant contacting pressure on upper and lower surfaces of the hand rails
1
.
The roller driving device
18
includes a plurality of driving rollers
18
a
and a plurality of driven rollers
18
b
which are mounted in a number corresponding to the driving rollers. The hand rail
1
is interposed between the driving rollers
18
a
and the driven rollers
18
b
, thus preserving the constant contacting pressure on the upper and lower surfaces of the hand rail
1
.
The frictional elastic body
16
or the tension is used for exerting a driving force of the hand rail
1
which is more than a fixed loss by bending resistivity(&egr;
&mgr;&thgr;
, friction coefficient, &thgr;: angle), and a pure friction force(&mgr;×m ) which increase proportionally corresponding to a change in a rise of an escalator.
However, when the rise of escalator increases, the hand rail driving apparatus of the conventional escalator as described above, needs to increase the tension of the flat belt
15
or to increase the contacting pressure between the driving rollers
18
a
and the driven rollers
18
b
in order to obtain a required driving force of the hand rail
1
. In addition, when increasing the tension and the contacting pressure, it can not only damage the flat belt
15
and the rollers
18
a
and
18
b
but also cause damage of the hand rail
1
.
Also, the increase of the driving force, that is, the increase of the tension and the contacting pressure causes decrease of the friction coefficient according to change of properties, thus making a normal operation of the hand rail
1
impossible.
On the other hand, in a conventional method of driving the hand rail of the escalator, a moving velocity of the hand rail
1
is determined by diameters of the hand rail driving pulley
13
and the driving roller
18
a.
However, when the diameters change by the wear of the hand rail
1
, the moving velocity of the hand rail
1
is not sufficiently compensated, thus causing problems of depreciating safety and convenience of the passengers.
In addition, when driving the hand rail
1
, severe vibrations are generated in the rate of 50-60[gal]. The conventional hand rail driving apparatus also has problems in which the vibration of the hand rail
1
is transmitted to the passengers directly.
Furthermore, because the hand rail
1
is driven by contacting friction of the frictional elastic body
16
, the apparatus acts with sufficient driving force only when there is no alien substance between the hand rail
1
and the frictional elastic body
16
, i.e., an indoor escalator. However, when rain, dust, and so on are collected therebetween such as in an outdoor location, the friction coefficient for driving the hand rail is decreased, degrading durability and reliance of the hand rail
1
. Therefore, there have been needs for correcting the above problems.
SUMMARY OF THE INVENTION
The present invention, therefore, is created to overcome the mentioned difficulties. Objects of the present invention are to provide new and improved hand rail driving apparatus which can easily compensate loss of a driving force and a tension of a hand rail, which is essential to safety of an escalator without damaging a flat belt or a roller, prevent vibration, generated in driving the hand rail, from being directly transmitted to the passengers; and prevent durability of the hand rail driving apparatus from being degraded by the interposition of an alien substance.
To accomplish the above objects, a first embodiment of the present invention contemplates the provision of a hand rail driving apparatus of an escalator in which a hand rail is contacted with pressure on a hand rail driving pulley, connected through a driving chain to a driving wheel, and in which the hand rail driving apparatus drives the hand rail while exerting pressure on the hand rail by using the driving pulley, comprising a tube, in which air pressure therein is variable, mounted on a circumferential surface of the hand rail driving pulley to which the hand rail is contacted with pressure.
To achieve the above object, the second embodiment of the present invention provides a hand rail driving apparatus comprising a roller unit for exerting pressure on both upper and lower surfaces of the hand rail when driving the hand rail by contacting with pressure the hand rail on a plurality of driving rollers and a plurality of driven rollers corresponding to the driving rollers, and tension rollers for transmitting power from a driving wheel to the roller unit, further comprising, a tube, in which air pressure therein is variable, mounted on a circumferential surface of the driving rollers of the roller unit.
In each embodiment of the present invention, the tube comprises a wave-shaped tread formed on a surface, contacting the hand rail, in a tangential direction thereof so as to eliminate an alien substance from being interposed in an inner circumferential surface, when the hand rail is driven by the hand rail driving pulley.
The tube, on which the wave-shaped tread is mounted, also comprises an air inlet for remotely blowing air from a remote air source
Hess Douglas
LG Industrial Systems Co. Ltd.
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