TECHNICAL FIELD
[0001] The present invention relates to a controller for a passenger conveyor which enables
variable speed operation.
BACKGROUND ART
[0002] In recent years, there has been known a passenger conveyor adapted to switch the
operation speed between a rated speed and a speed lower than the rated speed in accordance
with whether or not any passenger is present. However, most of the passenger conveyors
actually installed are usually operated at a rated speed regardless of whether or
nor any passenger is present.
[0003] But, in such a normal passenger conveyor as well, for example, when performing the
adjustment work in installation or the maintenance work after the installation, the
operation at a speed different from a rated speed may be required in some cases. For
this reason, a variable speed operating device (frequency converter) is attached to
a controller for normal passenger conveyor.
[0004] In addition, the conventional passenger conveyor as described above is disclosed
in, for example, JP 11-292450 A and JP 9-165183 A.
[0005] However, conventionally, since the variable speed operating devices are mounted to
individual passenger conveyors, respectively, the area required for installation of
the passenger conveyer becomes large. In addition, the price per passenger conveyor
is also increased.
DISCLOSURE OF THE INVENTION
[0006] The present invention has been made in order to solve the problems as described above,
and therefore, has an object to obtain a controller for a passenger conveyor which
enables reduction in an installation area of a passenger conveyor and also enables
reduction in price.
[0007] A controller for a passenger conveyor according to the present invention includes:
a controller main body for controlling a driving machine for a passenger conveyor
main body to operate the passenger conveyor main body at a rated speed; and a variable
speed control portion for controlling the driving machine to operate the passenger
conveyor main body at a speed different from the rated speed, in which the controller
main body is provided in the passenger conveyor main body, and the variable speed
control portion is constructed in the form of a portable type which is separate from
the controller main body and is mechanically and electrically connectable/disconnectable
to/from the controller main body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008]
Fig. 1 is a structural view showing a main portion of an escalator according to a
first embodiment of the present invention;
Fig. 2 is a circuit diagram showing a main portion of a controller for the escalator
of Fig. 1;
Fig. 3 is a circuit diagram showing a state in normal upward moving operation of the
controller of Fig. 2;
Fig. 4 is a circuit diagram showing a state in normal downward moving operation of
the controller of Fig. 2;
Fig. 5 is a circuit diagram showing a state in variable speed upward moving operation
of the controller of Fig. 2;
Fig. 6 is a circuit diagram showing a state in variable speed downward moving operation
of the controller of Fig. 2;
Fig. 7 is a circuit diagram showing a controller for an escalator according to a second
embodiment of the present invention;
Fig. 8 is a structural view showing a main portion of an escalator according to a
third embodiment of the present invention;
Fig. 9 is a front view showing a portion for accommodating a main body side connector
3 of Fig. 8;
Fig., 10 is a cross sectional view taken along a line X - X in Fig. 9;
Fig. 11 is a structural view showing a main portion of an escalator according to a
fourth embodiment of the present invention;
Fig. 12 is a circuit diagram showing a main portion of a controller for the escalator
of Fig. 11;
Fig. 13 is a side view showing a main portion of a controller for an escalator according
to a fifth embodiment of the present invention;
Fig. 14 is a side view showing a state in which a truck of Fig. 13 is laid on an escalator;
and
Fig. 15 is a cross sectional view of a main portion of the truck of Fig. 13.
BEST MODE FOR CARRYING OUT THE INVENTION
[0009] Preferred embodiment modes of the present invention will hereinafter be described
with reference to the accompanying drawings.
First embodiment
[0010] Fig. 1 is a structural view showing a main portion of an escalator according to a
first embodiment of the present invention. In the figure, an escalator main body 1
serving as a passenger conveyor main body has a plurality of steps 74 linked to one
another in an endless fashion (refer to Fig. 14), and an induction electric motor
20 (refer to Fig. 2) as a driving machine for moving these steps 74.
[0011] A controller main body 2 is arranged at one end portion in a longitudinal direction
of the escalator main body 1. More specifically, the controller main body 2 is accommodated
below a floor portion of a platform. The controller main body 2 controls the induction
electric motor 20 of the escalator main body 1 to operate the escalator main body
1 at a rated speed.
[0012] A portable type variable speed control portion 4 is connected to the controller main
body 2. The variable speed control portion 4 is constructed in a style separate from
the controller main body 2 and has a connection cable 5a and a portable side connector
5 for connection to the controller main body 2. The controller main body 2 is provided
with a main body side connector 3. The controller main body 2 and the variable speed
control portion 4 are mechanically and electrically connectable/disconnectable by
attaching/detaching the main body side and portable side connectors 3 and 5.
[0013] The variable speed control portion 4 controls the induction electric motor 20 of
the escalator main body 1 to operate the escalator main body 1 at a speed different
from the rated speed. In addition, the variable speed control portion 4 is moved in
a state of being laid on a truck 6.
[0014] Fig. 2 is a circuit diagram showing a main portion of the controller of the escalator
of Fig. 1. In the figure, the controller main body 2 has a main circuit 2a connected
between a power supply 11 and the induction electric motor 20, and a control circuit
2b for controlling a group of contacts of the main circuit 2a. A control power supply
is connected to,the control circuit 2b.
[0015] The main circuit 2a is provided with power-controlled power supply breakers 12, main
normally-open contacts 13A for normal operation, first main normally-open contacts
14A for variable speed operation, second main normally-open contacts 16A for variable
speed operation, main normally-open contacts 17A for upward moving operation, main
normally-open contacts 18A for downward moving operation, and over-current relays
19.
[0016] Power-controlled power supply breakers 12 and over-current relays 19 are connected
in series between the power supply 11 and the induction electric motor 20. Main normally-open
contacts 13A are connected between the power-controlled power supply breakers 12 and
the over-current relays 19.
[0017] The main normally-open contacts 14A and 16A are connected in parallel with the main
normally-open contacts 13A and between the power-controlled power supply breakers
12 and the over-current relays 19. When the variable speed control portion 4 is connected
to the controller main body 2, the main normally-open contacts 16A are connected in
series with the main normally-open contacts 14A.
[0018] Main normally-open contacts 17A and 18B are connected between the main normally-open
contacts 13A and 16A and the over-current relays 19. Any one of the main normally-open
contacts 17A and the main normally-open contacts 18A are selectively closed, whereby
the induction electric motor 20 is selectively driven either in an upward moving operation
direction or in a downward moving operation direction.
[0019] The control circuit 2b is provided with first to sixth electromagnetic contactors
13, 14, 16, 17, 18 and 21, an upward moving operation starting switch 31, a downward
moving operation starting switch 32, a self-holding circuit portion 61 and a safely
device group 62.
[0020] The first to sixth electromagnetic contactors 13, 14, 16, 17, 18 and 21 are connected
in parallel with one another with respect to the control power source. The safely
device group 62 is connected in parallel with the electromagnetic contactors 14 and
21.
[0021] The self-holding circuit portion 61 has a control normally-open contact 13a for normal
operation, control contact normally-closed contacts 13b1 and 13b2 for normal operation,
a control normally-open contact 16a for variable speed operation, control normally-open
contacts 17a1 and 17a2 for upward moving operation, a control normally-closed contact
17b for upward moving operation, control normally-open contacts 18a1 and 18a2 for
downward moving operation, a control normally-closed contact 18b for downward moving
operation, a normally-open contact 21a for change-over, and a normally-closed contact
21b for change-over.
[0022] The normally-closed contacts 13b1 and 13b2 are connected in series with the electromagnetic
contactors 14 and 21, respectively. The upward moving operation starting switch 31
and normally-closed contact 18b are connected in series with the electromagnetic contactor
17. The downward moving operation starting switch 32 and the normally-closed contact
17b are connected in series with the electromagnetic contactor 18.
[0023] The normally-closed contacts 21b is connected in series with the electromagnetic
contactor 13. The normally-open contact 21a is connected in series with the electromagnetic
contactor 16. A parallel circuit consisting of the normally-open contacts 13a and
16a is connected in series with a parallel circuit consisting of the normally-closed
contact 21b, the normally-open contact 21a, and the electromagnetic contactors 13
and 16. A parallel circuit consisting of the normally-open contacts 17a1 and 18a1
is connected in series with a parallel circuit consisting of the normally-open contacts
13a and 16a.
[0024] The normally-open contact 17a2 is connected between a node of the upward moving operation
starting switch 31 and the normally-closed contact 18b, and a node of the normally-open
contact 13a and the normally-closed contact 21b. The normally-open contact 18a2 is
connected between a node of the downward moving operation starting switch 32 and the
normally-closed contact 17b, and a node of the normally-open contact 16a and the normally-open
contact 21a.
[0025] The first electromagnetic contactor (electromagnetic contactor for normal moving
operation) 13 is excited, whereby the normally-open contacts 13a and 13A are closed,
and the normally-closed contact 13b is released. The second electromagnetic contactor
(electromagnetic contactor for variable speed operation) 14 is excited, whereby the
normally-open contacts 14A are closed. The third electromagnetic contactor (electromagnetic
contactor for variable speed operation) 16 is excited, whereby the normally-open contact
16a and 16A are closed.
[0026] The fourth electromagnetic contactor (electromagnetic contactor for upward moving
operation) 17 is excited, whereby the normally-open contacts 17a1, 17a2 and 17A are
closed, and the normally-closed contact 17b is released. The fifth electromagnetic
contactor (electromagnetic contactor for downward moving operation) 18 is excited,
whereby the normally-open contacts 18a1, 18a2 and 18A are closed, and the normally-closed
contact 18b is released. The sixth electromagnetic contactor (electromagnetic contactor
for variable speed operation) 21 is excited, whereby the normally-open contact 21a
is closed, and the normally-closed contact 21b is released.
[0027] Next, the operation will be described. In the normal operation, the variable speed
control portion 4 is not connected to the controller main body 2. If the upward moving
operation starting switch 31 is turned ON under this state, then the electromagnetic
contactor 17 is excited to close the normally-open contacts 17a1, 17a2 and 17A and
also to release the normally-closed contact 17b. As a result, the electromagnetic
contactor 13 is excited to close the normally-open contacts 13a and 13A and also to
release the normally-closed contact 13b.
[0028] Fig. 3 is a circuit diagram showing a state during the normal upward moving operation
of the controller of Fig. 2. While the upward moving operation starting switch 31
is automatically returned back to an OFF state after the manipulation, since as shown
in Fig. 3, a self-holding circuit is formed in the self-holding circuit portion 61,
the exciting state of electromagnetic contactors 13 and 17 is maintained and hence
the induction electric motor 20 is driven in the upward moving operation direction.
[0029] Next, in the state in which the variable speed control portion 4 is not connected
to the controller main body 2, if the downward moving operation starting switch 32
is turned ON under this state, then the electromagnetic contactor 18 is excited to
close the normally-open contacts 18a1, 18a2 and 18A and also to release the normally-closed
contact 18b. As a result, the electromagnetic contactor 13 is excited to close the
normally-open contacts 13a and 13A and also to release the normally-closed contact
13b.
[0030] Fig. 4 is a circuit diagram showing a state during the normal downward moving operation
of the controller of Fig. 2. While the downward moving operation starting switch 32
is automatically returned back to an OFF state after the manipulation, since as shown
in Fig. 4, a self-holding circuit is formed in the self-holding circuit portion 61,
the exciting state of electromagnetic contactors 13 and 18 is maintained and hence
the induction electric motor 20 is driven in the downward moving operation direction.
[0031] Next, in the adjustment work during the installation, the maintenance work or the
like, the escalator is operated at a variable speed. For this reason, a variable speed
control portion 4 is connected to the controller main body 2. Thus, the electromagnetic
contactor 14 is excited to close the normally-open contacts 14A. In addition, the
electromagnetic contactor 21 is excited to close the normally-open contact 21a and
also to release the normally-closed contact 21b.
[0032] If the upward moving operation starting switch 31 is turned ON under this state,
then the electromagnetic contactor 17 is excited to close the normally-open contacts
17a1, 17a2 and 17A and also to release the normally-closed contact 17b. As a result,
the electromagnetic contactor 16 is excited to close the normally-open contacts 16a
and 16A.
[0033] Fig. 5 is a circuit diagram showing a state during the variable speed upward moving
operation of the controller of Fig. 2. While the upward moving operation starting
switch 31 is automatically returned back to an OFF state after the manipulation, since
as shown in Fig. 5, a self-holding circuit is formed in the self-holding circuit portion
61, the exciting state of electromagnetic contactors 16 and 17 is maintained and hence
the induction electric motor 20 is driven in the upward moving operation direction
through the variable speed control portion 4.
[0034] In addition, in the state in which the variable speed control portion 4 is connected
to the controller main body 2, if the downward moving operation starting switch 32
is turned ON under this state, then the electromagnetic contactor 18 is excited to
close the normally-open contacts 18a1, 18a2 and 18A and also to release the normally-closed
contact 18b. As a result, the electromagnetic contactor 16 is excited to close the
normally-open contacts 16a and 16A.
[0035] Fig. 6 is a circuit diagram showing a state during the variable speed downward moving
operation of the controller of Fig. 2. While the downward moving operation starting
switch 32 is automatically returned back to an OFF state after the manipulation, since
as shown in Fig. 6, a self-holding circuit is formed in the self-holding circuit portion
61, the exciting state of electromagnetic contactors 16 and 18 is maintained and hence
the induction electric motor 20 is driven in the downward moving operation direction
through the variable speed control portion 4.
[0036] In addition, in either operation state, if a circuit in the safety device group 62
is electrically insulated, then the supply of currents to the electromagnetic contactors
13, 16, 17 and 18 are cut off. As a result, the main normally-open contacts 13A, 14A,
16A and 18A of the main circuit 2 are released to stop the driving of the induction
electric motor 20.
[0037] In such a controller for an escalator, since the variable speed control portion 4
is separable from the controller main body 2 for performing the normal operation,
and a plurality of escalators can share the variable speed control portion 4 with
one another, it is possible to reduce the installation area of the escalator and also
to reduce the cost thereof.
Second embodiment
[0038] Next, Fig. 7 is a circuit diagram showing a controller for an escalator according
to a second embodiment of the present invention. In the figure, the variable speed
control portion 4 is provided with a control change-over switch 33 which is connected
in series with a sixth electromagnetic contactor 21 when the variable speed control
portion 4 is connected to the controller main body 2. Other constitution is the same
as that of the first embodiment.
[0039] In such a controller, even when the variable speed control portion 4 is connected
to the controller main body 2, if the control change-over switch 33 is in a released
state, then the electromagnetic contactor 21 is not excited, and thus no variable
speed operation is performed. Therefore, in the case where the control change-over
switch 33 is held in a state of being turned OFF and either an upward moving operation
starting switch 31 or a downward moving operation starting switch 32 is turned ON
under this state, the variable speed control portion 4 does not become valid, and
hence either the normal upward moving operation or the normal downward moving operation
is performed.
[0040] That is to say, in a state in which the variable speed control portion 4 is connected
to the controller main body 2, the control change-over switch 33 is manipulated, whereby
the normal operation and the variable speed operation can be readily changed over
to each other.
[0041] By the way, while in the second embodiment, the control change-over switch 33 is
provided in the variable speed control portion 4, the control change-over switch 33
may also be provided on the controller main body 2 side.
Third embodiment
[0042] Next, Fig. 8 is a structural view showing a main portion of an escalator according
to a third embodiment of the present invention. In the figure, the main body side
connector 3 is provided in an outer plate 7 as an armour portion of the controller
main body 2. The main body side connector 3 and the controller main body 2 are connected
to each other through a connection cable 3a.
[0043] Fig. 9 is a front view showing a portion for accommodating the main body side connector
3, and Fig. 10 is a cross sectional view taken along a line X - X in Fig. 9. The main
body side connector 3 is accommodated in a case 8 fixed to the outer plate 7. A cover
9 is attached to the front surface of the case 8 through a hinge 9a. The cover 9 is
provided with a key device 10 for holding the closed state of the cover 9.
[0044] In accordance with such a controller, since the main body side connector 3 is provided
in the outer plate 7, the variable speed control portion 4 can be readily connected
to the controller main body 2. In addition, since the main body side connector 3 is
accommodated in the case 8 and the front surface of the case 8 is closed by the cover
9 with the key device 10, mischief to the main body side connector 3 is prevented.
[0045] By the way, while in the third embodiment, the main body side connector is provided
in the outer plate 7, it may also be provided in an armour portion such as an outer
deck.
Fourth embodiment
[0046] Next, Fig. 11 is a structural view showing a main portion of an escalator according
to a fourth embodiment of the present invention. The controller main body 2 and the
main body side connector 3 are arranged in the upper end portion of the escalator
main body 1 (refer to Fig. 1 and Fig. 8), whereas in this example, an additional connection
connector 71 is arranged in the lower end portion of the escalator main body 1. The
additional connection connector 71 and the controller main body 2 are connected to
each other through a connection cable 71a.
[0047] Fig. 12 is a circuit diagram showing a main portion of the controller of the escalator
of Fig. 11. In the figure, the controller main body 2 has a main circuit 2a connected
between the power supply 11 and the induction electric motor 20, and a control circuit
2b for controlling a group of contacts of the main circuit 2a. A control power supply
is connected to the control circuit 2b.
[0048] The main circuit 2a is provided with power-controlled power supply breakers 12, main
normally-open contacts 13A for normal operation, first main normally-open contacts
14A for variable speed operation, second main normally-open contacts 16A for variable
speed operation, main normally-open contacts 17A for upward moving operation, main
normally-closed contacts 18A for downward moving operation, over-current relays 19,
third main normally-open contacts 22A for variable speed operation, and fourth main
normally-open contacts 24A for variable speed operation.
[0049] The main normally-open contacts 22A and 24A are connected in parallel with the main
normally-open contacts 13A and between the power-controlled power supply breakers
12 and the over-current relays 19. When the variable speed control portion 4 is connected
to the controller main body 2, the main normally-open contacts 22A are connected in
series with the main normally-open contacts 24A.
[0050] The control circuit 2b is provided with first to ninth electromagnetic contactors
13, 14, 16, 17, 18, 21, 22, 23 and 24, an upward moving operation starting switch
31, a downward moving operation starting switch 32, a self-holding circuit portion
61 and a safely device group 62.
[0051] The first to ninth electromagnetic contactors 13, 14, 16, 17, 18, 21, 22, 23 and
24 are connected in parallel with one another with respect to the control power source.
[0052] The self-holding circuit portion 61 has a control normally-open contact 13a for normal
operation, control normally-closed contacts 13b1 to 13b4 for normal operation, control
normally-open contacts 16a and 24a for variable speed operation, control normally-open
contacts 17a1 and 17a2 for upward moving operation, a control normally-closed contact
17b for upward moving operation, control normally-open contacts 18a1 and 18a2 for
downward moving operation, a control normally-closed contact 18b for downward moving
operation, normally-open contacts 21a and 23a for change-over, and normally-closed
contacts 21b1, 21b2, 23b1 and 23b2 for change-over.
[0053] The normally-closed contacts 13b1 to 13b4 are connected in series with the electromagnetic
contactors 14, 21, 22 and 23, respectively.
[0054] The normally-closed contacts 21b1 and 23b1 are connected in series with the electromagnetic
contactor 13. The normally-open contact 23a and the normally-closed contact 21b2 are
connected in series with the electromagnetic contactor 24. The normally-open contact
21a and the normally-closed contact 23b2 are connected in series with the electromagnetic
contactor 16. A parallel circuit consisting of the normally-open contacts 13a, 16a
and 24a is connected in series with a parallel circuit consisting of the normally-closed
contacts 21b1, 21b2, 23b1 and 23b2, the normally-open contacts 21a and 23a, and the
electromagnetic contactors 13, 16 and 24. Aparallel circuit consisting of the normally-open
contacts 17a1 and 18a1 is connected in series with a parallel circuit consisting of
the normally-open contacts 13a, 16a and 24a.
[0055] The normally-open contact 17a2 is connected between a node of the upward moving operation
starting switch 31 and the normally-closed contact 18b, and a node of the normally-open
contact 13a and the normally-closed contact 23b1. The normally-open contact 18a2 is
connected between a node of the downward moving operation starting switch 32 and the
normally-closed contact 17b, and a node of the normally-open contact 16a and the normally-open
contact 23b2.
[0056] The sixth electromagnetic contactor (electromagnetic contactor for variable speed
operation) 21 is excited, whereby the normally-open contact 21a is closed, and the
normally-closed contacts 21b1 and 21b2 are released. The seventh electromagnetic contactor
(electromagnetic contactor for variable speed operation) 22 is excited, whereby the
normally-open contacts 22A are closed. The eighth electromagnetic contactor (electromagnetic
contactor for variable speed operation) 23 is excited, whereby the normally-open contact
23a is closed and the normally-closed contacts 23b1 and 23b2 are released. The ninth
electromagnetic contactor (electromagnetic contactor for variable speed operation)
24 is excited, whereby the normally-open contacts 24a and 24A are released. other
constitution is the same as that of the embodiment mode 1.
[0057] Next, the operation will be described. The operation in the normal operation is nearly
the same as that in the first embodiment. In addition, the operation when the variable
speed control portion 4 is connected to the main body side connector 3 is also nearly
the same as that in the first embodiment.
[0058] On the other hand, when the variable speed control portion 4 is connected to the
controller main body 2 through the additional connection connector 71, the electromagnetic
contactor 22 is excited to close the normally-open contact 22A. In addition, the electromagnetic
contactor 23 is excited to close the normally-open contact 23a and also to release
the normally-closed contacts 23b1 and 23b2.
[0059] If the upward moving operation starting switch 31 is turned ON under this state,
then the electromagnetic contactor 17 is excited to close the normally-open contacts
17a1, 17a2 and 17A and also to release the normally-closed contact 17b. As a result,
the electromagnetic contactor 24 is excited to close the normally-open contacts 24a
and 24A.
[0060] While the upward moving operation starting switch 31 is automatically returned back
to an OFF state after the manipulation, a self-holding circuit is formed in the self-holding
circuit portion 61, the exciting state of electromagnetic contactors 24 and 17 is
maintained and hence the induction electric motor 20 is driven in the upward moving
operation direction through the variable speed control portion 4.
[0061] In addition, in the state in which the variable speed control portion 4 is connected
to the controller main body 2 through the additional connection contactor 71, if the
downward moving operation starting switch 32 is turned, then the electromagnetic contactor
18 is excited to close the normally-open contacts 18a1, 18a2 and 18A and also to release
the normally-closed contact 18b. As a result, the electromagnetic contactor 24 is
excited to close the normally-open contacts 24a and 24A.
[0062] While the downward moving operation starting switch 32 is automatically returned
back to an OFF state after the manipulation, a self-holding circuit is formed in the
self-holding circuit portion 61, the exciting state of electromagnetic contactors
24 and 18 is maintained and hence the induction electric motor 20 is driven in the
downward moving operation direction through the variable speed control portion 4.
[0063] In such a controller for an escalator, in the end portion as well of the escalator
main body 1 on the side opposite to the installation place of the controller main
body 2, the variable speed control portion 4 can be readily connected to the controller
main body 2 and also the working efficiency can be enhanced.
Fifth embodiment
[0064] Next, Fig. 13 is a side view showing a main portion of a controller for an escalator
according to a fifth embodiment of the present invention. In the figure, an antislipping
member 73 is fixed to a lower portion of a base 72 of a truck 6 loaded with the variable
speed control portion 4. The antislipping member 73 is provided with a plurality of
stepped portions 73a. As shown in Fig. 14, when the truck 6 is laid on the escalator,
the stepped portions 73a are engaged with the end portions of steps 74 to prevent
the truck 6 from slipping down.
[0065] By using such a truck 6, the truck 6 can be safely laid on the steps 74 and also
the variable control portion 4 can be safely transferred.
[0066] Fig. 15 is a cross sectional view of a main portion of the truck 6 of Fig. 13. In
the figure, a plurality of rotatable wheels 75 are provided in the lower portion of
the base 72. A pair of brake arms 76a and 76b are pivoted with an arm fulcrum 77 as
a center. Brake shoes 78a and 78bwhich are brought in contact with or separated from
the wheels 75 are fixed to the brake arms 76a and 76b by the pivot of the brake arms
76a and 76b, respectively.
[0067] A post 79 is standingly provided on the base 72. A lever 81 which is pivotable with
a lever fulcrum 80 as a center is provided at the upper end portion of the post 79.
A pair of guide members 82a and 82b are fixed to the post 79. An upper end portion
of a rod 83 is pivotably linked to the lever 81. The rod 83 is provided so as to pass
through the guide members 82a and 82b and is displaced in the vertical direction by
operating pivotably the lever 81.
[0068] A spring bearing 84 located between the guide members 82a and 82b is fixed to the
rod 83. A pair of springs 85a and 85b are disposed between the guide members 82a and
82b, and the spring bearing 84. Brake links 86a and 86b are linked between the lower
end portion of the rod 83 and the brake arms 76a and 76b, respectively.
[0069] In such a truck 6, when no external force is applied to the lever 81, the rod 83
is held in the neutral position by the balance between the springs 85a and 85b. Under
this state, the brake shoes 78a and 78b are brought in contact with the wheels 76
and hence the wheels 76 are subjected to braking.
[0070] When the truck 6 is intended to be moved, the lever 81 is pivoted either upward or
downward. As a result, the rod 83 is displaced either upward or downward to pivot
the brake arms 76a and 76b so that the wheels 76 are made to separate from the brake
shoes 78a and 78b. Since the brake links 86a and 86b are linked between the rod 83,
and the brake arms 76a and 76b, even when the rod 83 is displaced either upward or
downward, the brake arms 76a and 76b are pivoted in the open direction.
[0071] The brake shoes 78a and 78b are made to separate from the wheels 76 so that the wheels
76 become rotatable to allow the truck 6 to be moved. The braking device of the fifth
embodiment has the brake arms 76a and 76b, the arm fulcrum 77, the brake shoes 78a
and 78b, the post 79, the lever fulcrum 80, the lever 81, the guide members 82a and
82b, the rod 83, the spring bearing 84, the springs 85a and 85b, and the brake links
86a and 86b.
[0072] By loading such a truck 6 with the variable speed control portion 4, even when the
truck 6 is laid on the inclination, the truck 6 can be stably held in a stop state,
and the variable speed control portion 4 can be prevented from being damaged.
[0073] By the way, while in the above-mentioned examples, the escalator is shown as the
passenger conveyor, the present invention can also be applied to a controller for
a moving sidewalk.