DESCRIPTION
TITLE OF THE INVENTION
Railway platform door device
TECHNICAL FIELD
[0001]
The present invention relates to a platform door device.
BACKGROUND ART
[0002]
Heretofore, there has been known a platform door device installed along an edge of a
platform on the side of a rail track in order to ensure safety of passengers. One example of such
a platform door device is disclosed in the following Patent Document 1.
[0003]
A platform door device disclosed in the Patent Document 1 comprises a door, a guiding
mechanism, and a driving mechanism.
[0004]
The door has a panel-shaped portion composed of a frame assembly and a glass plate set in
the frame assembly. The door is adapted to be guided by the guiding mechanism in such a
manner as to be movable forwardly and backwardly in a horizontal direction along an edge of a
platform.
[0005]
The guiding mechanism includes a linear rail attached to the frame assembly of the door so
as to extend in a direction of the movement of the door, and a slide block fixed to an inside of a
guide box installed on the platform and slidably provided to the linear rail.
[0006]
The driving mechanism is provided inside the guide box and beneath the door. The
driving mechanism includes a motor, a driving pulley, a pair of idler pulleys, and a toothed belt.

The driving pulley has teeth, and is adapted to be rotated according to driving of the motor.
The pair of idler pulleys are disposed to interpose the driving pulley therebetween. The toothed
belt is wound over the pair of idler pulleys and meshed with the teeth of the driving pulley at a
position between the idler pulleys. One end of the toothed belt is attached to a lower region of
one end of the frame assembly in the movement direction of the door, through a bracket. The
other end of the toothed belt is attached to a lower region of the other end of the frame assembly
in the movement direction of the door, through a bracket. The toothed belt is held between the
both ends of the frame assembly of the door, while being tightened with a given tension.
[0007]
In the driving mechanism, the driving pulley is rotated according to driving of the motor,
and thereby the toothed belt is moved. According to the movement of the toothed belt, the door
is pulled and thereby moved forwardly or backwardly. Then, according to the forward and
backward movements of the door, a gate on the platform is opened and closed.
[0008]
In the above platform door device, in the event of damage to the panel-shaped portion of the
door, the damaged door will be replaced with a new one. In this replacement operation, it is
necessary to detach the toothed belt from the frame assembly. Then, after attaching a new door
to the platform door device, and attaching the toothed belt between both ends of a lower portion
of a frame assembly of the new door, it is necessary to perform adjustment of the driving
mechanism, such as adjustment of belt tension. This causes a problem of an increase in time
required for the replacement operation.
PRIOR ART DOCUMENT
[PATENT DOCUMENT]
[0009]
Patent Document 1: JP 2006-240529A
SUMMARY OF THE INVENTION
[0010]

It is an object of the present invention to provide a platform door device capable of reducing
a time required for a replacement operation in the event of damage to a panel-shaped portion of a
door.
[0011]
A platform door device according to one aspect of the present invention comprises a door,
and a driving mechanism for moving the door forwardly and backwardly to close and open a
gate on a platform, wherein: the driving mechanism includes a motor, a rotation body adapted to
be rotated by the motor, and a driven body adapted to be driven according to the rotation of the
rotation body so as to move the door; and the door has a panel-shaped main body, and a base
segment detachably joined to the main body and attached to the driven body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]
FIG. 1 is a front view of a platform door device according to an embodiment of the present
invention.
FIG. 2 is a diagram illustrating a guide box, a door and a support box, on a right side in
FIG. 1.
FIG. 3 is a fragmentary enlarged view of the structure in FIG. 2, wherein a panel member
located on an inner side of a platform is removed.
FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2.
FIG. 5 is a sectional view taken along the line V-V in FIG. 2.
FIG. 6 is a sectional view of the right guide box and door in FIG. 1, when viewed from a
trailing side of the door.
FIG. 7 is a fragmentary enlarged view of the structure in FIG. 6.
MODE FOR CARRYING OUT THE INVENTION
[0013]
The embodiments of the present invention will be described below with reference to the
drawings.

[0014]
FIG. 1 is a front view of a platform door device 10 according to one embodiment of the
present invention, when viewed in a direction from the side of a platform P to a rail track. As
illustrated in FIG. 1, the platform door device 10 comprises a pair of guide boxes 12, 12, and a
pair of doors 14, 14. The pair of guide boxes 12, 12 are installed on the platform P along an
edge of the platform P on the side of the track, while leaving a given distance therebetween.
The guide box 12 is included in a concept of "guide body" in the present invention. A support
box (illustration is omitted) and a fixed partition wall (illustration is omitted) may be installed
adjacent to the guide box 12. Each of the doors 14 is a sliding type, and supported by a
corresponding one of the guide boxes 12 in a movable manner.
[0015]
In cases where a large number of the platform door devices 10 are arranged along the edge
of the platform P while interposing the support box and the fixed partition wall therein, a space
on the platform P will be divided into a track-side space, and a space inward of the track-side
space (platform inner-side space). When the two doors 14 are in their closed positions as
illustrated in FIG. 1, a gate 20 between the pair of guide boxes 12 is closed. On the other hand,
when each of the doors 14 is driven by an aftermentioned driving mechanism 55 and thereby
moved backwardly to its opened position, the gate 20 is opened.
[0016]
Each of the guide boxes 12 is designed to.be installable on the platform P, and adapted to
allow the door 14 to penetrate therethrough in a direction along the track, i.e., a rightward-
leftward direction in FIG. 1. Although the platform door device 10 is formed as a so-called
double sliding-type movable fence, it is not limited thereto. For example, the platform door
device may be formed as a single sliding-type movable fence which comprises a single guide
box 12, and a single door 14 supported by the guide box 12.
[0017]
With reference to FIG. 2 to 7, respective specific structures of the guide box 12 and the door
14 will be described below. The guide box 12 and the door 14 on the left side in FIG. 1 are
structurally symmetrical to the guide box 12 and the door 14 on the right side in FIG. 1. Thus,

only the structures of the guide box 12 and the door 14 on the right side in FIG. 1 will be
described here.
[0018]
As illustrated in FIGS. 2 and 3, the guide box 12 comprises a base 22 fixed to the platform
P, and a casing 23 fixed to the base 22. The casing 23 has a bottom portion 25, a pair of end
walls 27, 28, a pair of lateral walls 29, 30, a top portion 31, and a support pillar 32. The bottom
portion 25 is fixed onto the base 22. The pair of end walls 27, 28 are disposed in spaced-apart
relation to each other in a widthwise direction of the casing 23, i.e., in a door opening/closing
direction. The pair of lateral walls 29, 30 are disposed in spaced-apart relation to each other in
a thicknesswise direction of the casing 23, i.e., in a direction perpendicular to the door
opening/closing direction. The top portion 31 connects between respective upper ends of the
end walls 27, 28 and between respective upper ends of the lateral walls 29, 30. Thus, the guide
box 12 is formed in a hollow structure having a rectangular cross-section in top plan view, as
illustrated in FIGS. 4 and 5. One of the pair of end walls located on the side of the gate 20 will
hereinafter be referred to as "leading-side end wall 27", and the other end wall located on the
opposite side will hereinafter be referred to as "trailing-side end wall 28". In the pair of lateral
walls 29, 30, the lateral wall 30 located on the side of the track is provided with two auxiliary
sensors 35 for detecting a passer passing through the gate 20, the auxiliary sensors 35 are
arranged upper portion and lower portion of the lateral wall 30.
[0019]
As illustrated in FIG. 2, in the pair of lateral walls 29, 30, the lateral wall 29 located on the
platform inner side is formed with an opening 29a. This opening 29a is used during
maintenance. A cover 29b to open and close the opening 29a is detachably attached to the
lateral wall 29 (see FIG. 1).
[0020]
As illustrated in FIGS. 4 and 5, the leading-side end wall 27 is formed with an opening 27a,
and the trailing-side end wall 28 is formed with an opening 28a. Each of the two openings 27a,
28a is designed to allow the door 14 to path therethrough. When the door 14 is in the closed
position, a trailing end of the door 14 is located adjacent to the trailing-side end wall 28, as

illustrated in FIGS. 4 and 5. On the other hand, when the door 14 is in the opened position, a
leading end of the door 14 is located adjacent to the leading-side end wall 27.
[0021]
As illustrated, for example, in FIG. 2, the door 14 comprises a panel-shaped main body 40,
and a base segment 42 detachably joined to the main body 40.
[0022]
The main body 40 includes a frame assembly 40a and a glass plate 40b. The frame
assembly 40a is formed by assembling a plurality of hollow frame members together in a frame
shape. The frame assembly 40a has an upper frame 40c, lower frame 40d, a leading frame 40e
and a trailing frame 40f. The upper frame 40c forms an upper end of the frame assembly 40a,
and the lower frame 40d forms a lower end of the frame assembly 40a. Each of the upper
frame 40c and the lower frame 40d extends horizontally along the door opening/closing
direction. The leading frame 40e forms a leading-side end of the frame assembly 40a, and the
trailing frame 40f forms a trailing-side end of the frame assembly 40a. Each of the leading
frame 40e and the trailing frame 40f extends in an upward-downward direction. The glass plate
40b serving as a panel member is fixedly attached to the frame assembly 40a so as to close a
space formed by the frames 40c, 40d, 40e, 40f. A panel member to be fixedly attached to the
frame assembly 40a is not limited to the glass plate 40b, but may be any other suitable type of
panel member, such as a transparent plate made of resin or the like, or a metal panel.
[0023]
The base segment 42 has a width dimension equal to that of the frame assembly 40a, in the
door opening/closing direction, i.e., in a widthwise direction of the door 14. Further, the base
segment 42 has a leading-side end surface flush with a leading-side end surface of the frame
assembly 40a, and a leading rubber 45 (see FIG. 2) is attached to cover across the two end
surfaces.
[0024]
The base segment 42 is detachably joined to the lower frame 40d of the frame assembly 40a
of the main body 40. An aftermentioned belt member 60 and an aftermentioned linear rail 64
are attached to the base segment 42. As illustrated in FIG. 7, the base segment 42 has a joining

portion 48, a mounting portion 49, and an extension portion 50. The joining portion 48, the
mounting portion 49 and the extension portion 50 are integrally formed. The joining portion 48
is formed to have a given width in the upward-downward direction, and located on a lateral side
of the lower frame 40d. The width of the joining portion 48 in the upward-downward direction
is set to a value approximately equal to a width of the lower frame 40d in the upward-downward
direction. A lateral surface of the joining portion 48 is joined to a lateral surface of the lower
frame 40d. The base segment 42 is provided with a bridging portion 53. The bridging portion
53 is bridged between an upper end of the joining portion 48 and a track-side end of an
aftermentioned upper section 49a of the mounting portion 49. The joining portion 48, the upper
section 49a of the mounting portion 49, and the bridging portion 53 are joined to each other to
form a closed loop cross-section.
[0025]
The joining portion 48 has a plurality of insertion holes formed in the door opening/closing
direction at given intervals. Each of the insertion holes penetrates through the joining portion
48 in a horizontal direction. A nut plate 52 formed with a plurality of threaded holes is
provided on a track-side of the joining portion 48 so as to extend along the joining portion 48.
The nut plate 52 is non-rotatably held by the bridging portion 53. On the other hand, a portion
of the lower frame 40d located on the side of the track is formed with insertion holes at positions
corresponding to respective ones of the insertion holes of the joining portion 48. A bolt 51
inserted from the platform inner side into corresponding ones of the insertion holes of the lower
frame 40d and the joining portion 48 is screwed in the nut plate 52, so that the joining portion 48
and the lower frame 40d are fixed together. In other words, the joining portion 48 is joined to
the frame assembly 40a from a lateral direction. A platform inner-side portion of the lower
frame 40d has a through-hole 40b 1 formed to allow the bolt 51 to be inserted therethrough, and a
cover 40b2 detachably attached thereto to close the through-hole 40bl.
[0026]
The frame assembly 40a can be separated from the base segment 42 by unfastening the
bolts 51 from the nut plate 51. Each of the bolts 51 is laterally inserted into the corresponding
insertion holes of the lower frame 40d and the joining portion 48 through the through-hole 40bl,

so that fastening and unfastening operations for the bolts 52 and the nut plate 52 can be
performed from the platform inner side.
[0027]
The mounting portion 49 is a region having rigidity capable of supporting the
aftermentioned linear rail 64. The mounting portion 49 is formed in a hollow shape extending
in a direction of the movement of the door 14. The mounting portion 49 is formed in a tubular
shape having a generally rectangular cross-section. The mounting portion 49 has an upper
section 49a, a lower section 49b, a first lateral section 49c, and a second lateral section 49d.
The upper section 49a, the lower section 49b, the first lateral section 49c and the second lateral
section 49d are integrally formed. The upper section 49a is a plate-shaped region which
extends in a horizontal direction and has a given width in a thicknesswise direction of the door
14. The joining portion 48 is provided to extend upwardly from a widthwise intermediate
region of the upper section 49a.
[0028]
The first lateral section 49c extends downwardly from one of widthwise opposite ends of
the upper section 49a, and the second lateral section 49d extends downwardly from the other end
of the upper section 49a. Each of the first lateral section 49c and the second lateral section 49d
has a given height dimension. The first lateral section 49c makes up a platform inner-side
lateral wall of the mounting portion 49, and the second lateral section 49d makes up a track-side
lateral wall of the mounting portion 49. The lower section 49b connects a lower end of the first
lateral section 49c and a lower end of the second lateral section 49d together, and extends
between these lower ends in a horizontal direction.
[0029]
The extension portion 50 is provided to extend downwardly directly from the first lateral
section 49c of the mounting portion 49. The extension portion 50 has a lower end 50a slightly
bulging toward the track within a thickness range of the frame assembly 40a. A first belt
joining portion 50b is provided on a trailing-side end of the lower end 50a, and a second belt
joining portion 50c is provided on a leading-side end of the lower end 50a. The first belt
joining portion 50b is a portion to be joined to one end of the aftermentioned belt member 60,

and the second belt joining portion 50c is a portion to be joined to the other end of the
aftermentioned belt member 60.
[0030]
The platform door device 10 comprises a driving mechanism 55 for moving the door 14
forwardly and backwardly to close and open the gate 20 on the platform P, and a guiding
mechanism 56 for guiding the door 14 which is being moved forwardly or backwardly. The
driving mechanism 55 and the guiding mechanism 56 are provided for each of the right and left
doors 14.
[0031]
As illustrated in FIGS. 2 and 3, the driving mechanism 55 includes a motor 58, a driving
pulley 59a, a pair of idler pulleys 59b, 59b, and a belt member 60. The driving pulley 59a is
included in a concept of "rotation body" of the present invention, and the idler pulley 59b is
included in a concept of "pulley" of the present invention. Further, the belt member 60 is
included in a concept of "driven body" of the present invention. The driving pulley 59a is
disposed just below the frame assembly 40a, and formed to fall approximately within the
thickness range of the frame assembly 40a.
[0032]
The motor 58 is fixed to the bottom portion 25 of the casing 23 through a motor bracket 61.
The motor bracket 61 is fixed to the bottom portion 25 by a non-illustrated bolt. The motor
bracket 61 has a size which falls within a width of the motor 58 in the thicknesswise direction of
the guide box 12.
[0033]
The motor 58 is disposed below a lower end of the door 14. Further, a part of the motor
58 is located within the thickness range of the frame assembly 40a. More specifically, the
motor 58 has a cylinder-shaped barrel portion 58a, and a part of the barrel portion 58a falls
within the thickness range of the frame assembly 40a. The motor 58 has a gear portion 58b
joined to the barrel portion 58a. The gear portion 58b has a width less than that of the barrel
portion 58a, and an output shaft is provided in the gear portion 58b. The gear portion 58b is not
located within the thickness range of the frame assembly 40a. Thus, the driving pulley 59 fixed

to the output shaft provided to protrude from the gear portion 58b falls approximately within the
thickness range of the frame assembly 40. The output shaft of the motor 58 is provided to
protrude toward the platform inner side with respect to the motor 58, in a posture where it is
rotatable about a horizontal axis. As above, a part of the motor 58 is disposed to fall within the
thickness range of the frame assembly 40a, so that it becomes possible to reduce the thickness of
the guide box 12 accordingly.
[0034]
The driving pulley 59a is fixed to the output shaft of the motor 58, and adapted to be rotated
according to driving of the motor 58. The driving pulley 59a has teeth.
[0035]
The pair of idler pulleys 59b, 59b are arranged at positions above the driving pulley 59a,
and separately on respective ones of opposite sides of a center position of the driving pulley 59a
in the movement direction of the door 14. The idler pulleys 59b are disposed in spaced-apart
relation to each other in the movement direction of the door 14. Each of the idler pulleys 59b is
provided in a rotatable manner. A rotation axis of each of the idler pulleys 59b is arranged
parallel to the output shaft of the motor 58.
[0036]
The belt member 60 is adapted to be driven according to rotation of the driving pulley 59a
so as to move the door 14. The belt member 60 includes a toothed belt 60a, and a fastener 60b
fixed to each of opposite ends of the toothed belt 60a.
[0037]
The toothed belt 60a is wound over the pair of idler pulleys 59b, 59b, and meshed with the
teeth of the driving pulley 59a at a position between the idler pulleys 59b, 59b. Specifically,
the idler pulleys 59b press regions of the toothed belt 60a on both sides of a portion of the
toothed belt 60a meshed with the driving pulley 59a. This makes it possible to ensure a length
of a meshable region of the toothed belt 60a with the driving pulley 59a. Under a condition that
teeth of the toothed belt 60a are meshed with the teeth of the driving pulley 59a, the opposite
ends of the belt member 60 are fixed to the base segment 42 of the door 14.
[0038]

The fastener 60b fixed to one (trailing-side) end of the toothed belt 60a is fastened to the
first belt joining portion 50b provided on the trailing-side end of the lower end 50a of the
extension portion 50 of the base segment 42. The fastener 60b fixed to the other (leading-side)
end of the toothed belt 60a is fastened to the second belt joining portion 50c provided on the
leading-side end of the lower end 50a of the extension portion 50 of the base segment 42 through
an adjustment mechanism 62 capable of adjusting tension of the toothed belt 60a. Based on this
structure, the toothed belt 60a is tightened with a given tension, between the first belt joining
portion 50b and the second belt joining portion 50c. Thus, when the driving pulley 59a is
rotated according to driving of the motor 58, the belt member 60 is moved according to the
rotation of the driving pulley 59a, so that the door 14 is pulled by the belt member 60and thereby
moved forwardly or backwardly.
[0039]
The guiding mechanism 56 includes a linear rail 64 and a guide block 65. The linear rail
64 is attached to a widthwise intermediate region of the lower section 49b of the mounting
portion 49 so as to extend in the movement direction of the door 14. The linear rail 64 has a
length extending over approximately the entire width of the door 14 in the opening/closing
direction of the door 14. The linear rail 64 is fixed to the mounting portion 49 while being
oriented downwardly. The linear rail 64 extends outside the guide box 12, together with the
door 14.
[0040]
The guide block 65 has a guide groove 65 a formed in an upper surface thereof. The linear
rail 64 is fitted in the guide groove 65a. Thus, the linear rail 64 is adapted to be slidingly
moved with respect to the guide block 65. A structure in which the linear rail 64 and the guide
block 65 are slidingly movable with respect to each other includes two structure: a first structure
in which the linear rail 64 and the guide block 65 are slidingly movable with respect to each
other while being in surface contact with each other; and a second structure in which the linear
rail 64 and the guide block 65 are slidingly movable with respect to each other through a rolling
element, such as a bearing ball.
[0041]

The two guide blocks 65 are provided within the guide box 12. The two guide blocks 65
are arranged while leaving a given distance therebetween in the door opening/closing direction.
Each of the guide blocks 65 is supported by a support body 68 fixed to the inside of the guide
box 12. The support body 68 has a pair of legs 68a, 68a fixed to the bottom portion 25 of the
casing 23, a standing plate 68b disposed between the legs 68a, 68a, and a loading portion 68c
fixed to respective upper ends of the legs 68a, 68a. The loading portion 68c is provided to
extend over a range between the legs 68a, 68a and ranges located outside the legs 68a, 68a, in the
door opening/closing direction. The two guide blocks 65 are fixed onto the loading portion
68c. In this state, the guide blocks 65 support the linear rail 64 from therebelow.
[0042]
The pair of legs 68a, 68a are disposed separately on both sides of the motor 58 in the door
opening/closing direction (see FIG. 3). Each of the legs 68a, 68a has a lower end bent in a
horizontal direction, and the lower end is fixed to the bottom portion 25 by a non-illustrated bolt.
[0043]
Each of the legs 68a has a reinforcement portion 68d at an intermediate height position
thereof. The reinforcement portion 68d is provided at approximately the same height position
as that of an upper end of the motor 58. As illustrated in FIG. 7, a concave portion 68e is
formed in a region of each of the legs 68a above the reinforcement portion 68d to avoid
interference with the lower end 50a of the extension portion 50 and the belt member 60.
[0044]
The standing plate 68b is provided above the reinforcement portion 68d. The standing
plate 68b is formed in a flat plate shape extending in a direction perpendicular to the output shaft
of the motor 58. A pulley bracket 69 is fixed to the standing plate 68b, and the two idler
pulleys 59b, 59b are rotatably attached to the pulley bracket 69 (see FIG. 3).
[0045]
The extension portion 50 of the base segment 42 is disposed on a side opposite to the track,
i.e., on the platform inner side with respect to the linear rail 64 and the guide blocks 65. The
extension portion 50 extends below the linear rail 64, the guide blocks 65 and the loading portion
68c. As illustrated in FIGS. 2 and 3, the extension portion 50 is formed with cutouts 50d. The

two cutouts 50d are provided at respective positions between the first belt joining portion 50b
and the second belt joining portion 50c to each of which a respective one of the opposite ends of
the belt member 60 is fixed, in spaced-apart relation to each other in the door opening/closing
direction. Based on forming the cutouts 50d in the extension portion 50, a part of each of the
guide blocks 65 and a part of the linear rail 64 are exposed through the cutouts 50d, when viewed
from the platform inner side. Thus, through the cutouts 50d, inspection of the linear rail 64, for
example, an inspection as to whether the linear rail 64 is damaged, can be easily performed.
Further, an oil hole 65b is provided in a region of the guide block 65 exposed through each of the
cutouts 50d. The oil hole 65b is intended to feed lubrication oil to a sliding contact portion of
each of the guide blocks 65 with respect to the linear rail 64. The oil hole 65b is used during
maintenance. With the oil hole 65b being exposed through the each of the cutouts 50d,
complexity in an operation of feeding oil to the oil hole 65b can be reduced.
[0046]
A cover panel 71 to cover the cutouts 50d is detachably attached to the base segment 42 of
the door 42. The cover panel 71 is included in a concept of "cover" of the present invention.
Based on covering the cutouts 50d by the cover panel 71, the guide blocks 65, the linear rail 64
and the belt member 60 located therebelow, exposed through the cutouts 50d, are hidden behind
the cover panel 71 (see FIG. 7). The cover panel 71 is attached to each of a platform inner-side
surface and a track-side surface of the base segment 42.
[0047]
As illustrated in FIG. 6, a guide roller 72 is provided in an upper region of the inside of the
guide box 12. An upper end of the door 14 is guided by the guide roller 72.
[0048]
As described above, in the platform door device 10 according to the present embodiment,
the door 14 includes the base segment 42 which is detachably joined to the panel-shaped main
body 40 and to which the belt member 60 of the driving mechanism 55 is attached. Thus, in the
event of damage to the panel-shaped main body 40, for example, in the event that the glass plate
40b of the main body 40 is broken, the main body 40 can be replaced by detaching the main
body 40 from the base segment 42 while allowing the belt member 60 to be kept attached to the

base segment 42, and attaching a new main body 40 to the base segment 42. This makes it
possible to replace the main body 40 without exerting any influence on the driving mechanism
55, which eliminates a need for adjustment of the driving mechanism 55 during the replacement
operation for the main body 40. Therefore, in the event of damage to the main body 40 of the
door 14, a time required for the replacement operation can be reduced.
[0049]
Meanwhile, in a structure where the belt member 60 is directly joined to the main body of
the door 14 and tightened with a given tension, when the main body is detached from the belt
member 60 during replacement of the main body, the tension of the belt member 60 is loosened.
Thus, it is necessary to re-adjust the tension of the belt member 60. However, in the structure
according to the present embodiment, the belt member 60 is attached to the base segment 42 of
the door 14, and the main body 40 of the door 14 is detachably joined to the base segment 42, so
that it becomes possible to allow the belt member 60 to be kept joined to the base segment 42
while being tightened with a given tension, during replacement of the main body 40. Thus, it is
not necessary to perform adjustment of the tension of the belt member 60, i.e., a complicate
operation in connection with the replacement of the main body 40.
[0050]
In the present embodiment, the base segment 42 of the door 14 is attached to the linear rail
64 of the guiding mechanism 56. Thus, in the event of damage to the main body 40 of the door
14, the main body 40 can be replaced by detaching the main body 40 from the base segment 42
while allowing the linear rail 64 to be kept attached to the base segment 42, and attaching a new
main body 40 to the base segment 42. In other words, during replacement of the main body 40,
it is only necessary to detach the main body 40 from the base segment 42 and attach a new main
body 40 to the base segment 42, so that it becomes possible to omit an operation of attaching and
detaching the door 14 with respect to each of the belt member 60 of the driving mechanism 55
and the linear rail 64 of the guiding mechanism 56. This makes it possible to simplify the
replacement operation for the main body 40 of the door 14.
[0051]
In the present embodiment, the cutouts 50d to expose a part of the linear rail 64 and each of

the guide blocks 65 are provided in the extension portion 50 of the base segment 42 located on
the side opposite to the track with respect to the linear rail 64 and the guide blocks 65. Thus,
even if the extension portion 50 covers the linear rail 64 and the guide blocks 65, at a position
opposite to the track with respect to the linear rail 64 and the guide blocks 65, maintenance of the
linear rail 64 and the guide blocks 65 can be performed on the platform P through the cutouts
50d. This makes it possible to easily perform the maintenance of the guiding mechanism 56.
[0052]
In the present embodiment, the cover panel 71 to cover the cutouts 50d is detachably
attached to the base segment 42. Thus, during a normal actuation of the platform door device
10, the cutouts 50d can be covered by the cover panel 71 so as to prevent foreign substances such
as dust from entering through the cutouts 50d. Further, during maintenance, the cover panel 71
can be detached so as to easily perform the maintenance of the linear rail 64 and the guide blocks
65 through the cutouts 50d.
[0053]
It is understood that the present invention is not limited to the present embodiment, but
various changes and modifications may be made therein without departing from the spirits and
scope of the present invention.
[0054]
For example, although the present embodiment has been described based on a structure in
which the door 14 penetrates through the guide box 12 as one example of a guide body, and the
trailing end of the door 14 in the opened position protrudes from the guide box 12, the present
invention is not limited to this structure. For example, the door 14 may be housed in a door
case body as another example of the guide body, when it is in the opened position.
[0055]
Although the present embodiment has been described based on a so-called belt drive system
in which the driving mechanism 55 includes the driving pulley 59a and the belt member 60, and
the door 14 is openably/closably driven by the belt member 60, the present invention is not
limited thereto. For example, the driving mechanism may be a driving mechanism based on a
rack-and-pinion drive system. In this case, a rack (illustration is omitted) may be fixed to a

lower surface of the extension portion 50 located at the lower end of the door 14, and a pinion as
a rotation body attached to the output shaft of the motor 58 may be meshed with the rack. In
the driving mechanism based on the rack-and-pinion drive system, as long as the frame assembly
40a of the main body 40 is adapted to be detachable from the base segment 42, a burden of the
replacement operation for the main body 40 can be reduced, and a time required for the
replacement operation can be reduced.
[0056]
In the present embodiment, the linear rail 64 is attached to the mounting portion 49 of the
base segment 42, and each of the guide blocks 65 is fixed to the support body 68 within the
guide box 12. Alternatively, each of the guide blocks 65 may be attached to the mounting
portion 49 of the base segment 42, and the linear rail 64 may be fixed to the support body 68
within the guide box 12. In this case, the guide body may be formed as a door case body
adapted to house the door 14 in the opened position.
[0057]
[SUMMARY OF THE EMBODIMENT]
The above embodiment can be summarized as follows.
[0058]
The platform door device according to the above embodiment comprises a door, and a
driving mechanism for moving the door forwardly and backwardly to close and open a gate on a
platform, wherein: the driving mechanism includes a motor, a rotation body adapted to be rotated
by the motor, and a driven body adapted to be driven according to the rotation of the rotation
body so as to move the door; and the door includes a panel-shaped main body, and a base
segment which is detachably joined to the main body and to which the driven body is attached.
[0059]
In this platform door device, the door includes the base segment which is detachably joined
to the panel-shaped main body and to which the driven body of the driving mechanism is
attached. Thus, in the event of damage to the panel-shaped main body, the main body can be
replaced by detaching the main body from the base segment and attaching a new main body to
the base segment while allowing the driven body to be kept attached to the base segment. This

makes it possible to replace the panel-shaped main body of the door without exerting any
influence on the driving mechanism, which eliminates a need for adjustment of the driving
mechanism during the replacement operation for the main body. Therefore, in the platform
door device, in the event of damage to the panel-shaped main body of the door, a time required
for the replacement operation can be reduced.
[0060]
In the above platform door device, the driving mechanism may include a pair of pulleys
separately arranged on respective ones of opposite sides of the rotation body, wherein the
rotation body may have teeth; the driven body may consist of a belt member which is wound
over the pair of pulleys and meshed with the teeth of the rotation body at a position between the
pulleys; and the base segment may be provided with a first belt joining portion joined to one end
of the belt member, and a second belt joining portion joined to the other end of the belt member
while allowing the belt member to be tightened with a given tension.
[0061]
In this structure, the rotation body is rotated and the belt member is moved, according to
driving of the motor, so that the door can be pulled by the belt member and thereby moved
forwardly or backwardly. This makes it possible to form a specific structure of the driving
mechanism for moving the door forwardly and backwardly. In a structure where a belt member
is used as the driven body to move the door, if the belt member is directly joined to the main
body of the door and tightened with a given tension, the tension of the belt member is loosened
during replacement of the main body. Thus, it is necessary to re-adjust the tension of the belt
member. However, in the structure according to the above embodiment, it becomes possible to
allow the belt member to be kept joined to the base segment while being tightened with a given
tension, during replacement of the main body of the door. Thus, it is not necessary to perform
the complicate adjustment.
[0062]
Preferably, the above platform door device comprises a guide body installed on the
platform, and a guiding mechanism for guiding the door which is being moved forwardly or
backwardly, wherein the guiding mechanism includes a linear rail extending in a direction of the

movement of the door, and a guide block adapted to be slidingly moved with respect to the linear
rail, and wherein one of the linear rail and the guide block is attached to the base segment, and a
remaining one of the linear rail and the guide block is fixed to the guide body.
[0063]
In this structure, the base segment of the door is attached to the linear rail or the guide block
of the guiding mechanism. Thus, in the event of damage to the panel-shaped main body of the
door, the main body can be replaced by detaching the main body from the base segment and
attaching a new main body to the base segment while allowing the linear rail or the guide block
to be kept attached to the base segment,. In other words, in this structure, during replacement
of the main body of the door, it is only necessary to detach the main body from the base segment
and attach a new main body to the base segment, so that it becomes possible to omit an operation
of attaching and detaching the door with respect to each of the driven member of the driving
mechanism and the linear rail or the guide block of the guiding mechanism. This makes it
possible to simplify the replacement operation for the main body of the door.
[0064]
In this case, it is preferable that the base segment has a portion which is located on a side
opposite to a track with respect to the linear rail and the guide block, and formed with a cutout
for exposing at least a part of the linear rail and the guide block.
[0065]
In this structure, even if a portion of the base segment covers the linear rail and the guide
block, at a position opposite to the track with respect to the linear rail and the guide block,
maintenance of the linear rail and the guide block can be performed on the platform through the
cutout. This makes it possible to easily perform the maintenance of the guiding mechanism.
[0066]
Further, in this case, it is preferable that the platform door device comprises a cover for
covering the cutout, that is detachably attached to the base segment.
[0067]
In this structure, during a normal actuation of the platform door device, the cutout can be
covered by the cover so as to prevent foreign substances such as dust from entering through the

cutout. Further, during maintenance, the cover can be detached so as to easily perform the
maintenance of the linear rail and the guide block through the cutout.
[0068]
As mentioned above, the platform door device according to the above embodiment makes it
possible to reduce a time required for a replacement operation in the event of damage to the
panel-shaped main body of the door.

CLAIMS
[Claim 1]
A platform door device comprising a door, and a driving mechanism for moving the door
forwardly and backwardly to close and open a gate on a platform, wherein:
the driving mechanism includes a motor, a rotation body adapted to be rotated by the motor,
and a driven body adapted to be driven according to the rotation of the rotation body so as to
move the door; and
the door includes a panel-shaped main body, and a base segment which is detachably joined
to the main body and to which the driven body is attached.
[Claim 2]
The platform door device according to claim 1, wherein the driving mechanism includes a
pair of pulleys separately arranged on respective ones of opposite sides of the rotation body, and
wherein:
the rotation body has teeth;
the driven body consists of a belt member which is wound over the pair of pulleys and
meshed with the teeth of the rotation body at a position between the pulleys; and
the base segment is provided with a first belt joining portion joined to one end of the belt
member, and a second belt joining portion joined to the other end of the belt member while
allowing the belt member to be tightened with a given tension.
[Claim 3]
The platform door device according to claim 1 or 2, which comprises a guide body installed
on the platform, and a guiding mechanism for guiding the door which is being moved forwardly
or backwardly, wherein the guiding mechanism includes a linear rail extending in a direction of
the movement of the door, and a guide block adapted to be slidingly moved with respect to the
linear rail, and wherein one of the linear rail and the guide block is attached to the base segment,
and a remaining one of the linear rail and the guide block is fixed to the guide body.

[Claim 4]
The platform door device according to claim 3, wherein the base segment has a portion
which is located on a side opposite to a track with respect to the linear rail and the guide block,
and formed with a cutout for exposing at least a part of the linear rail and the guide block.
[Claim 5]
The platform door device according to claim 4, which comprises a cover, for covering the
cutout, that is detachably attached to the base segment.

Provided is a platform door device which makes it possible to reduce the length of time for
a replacement operation when a panel-shaped portion of a door is damaged. The platform door
device comprises a door, and a driving mechanism for moving the door forwardly and
backwardly to close and open a gate on a platform. The driving mechanism includes a motor, a
rotation body adapted to be rotated by the motor, and a driven body adapted to be driven
according to the rotation of the rotation body so as to move the door, and the door has a
panel-shaped main body, and a base segment detachably joined to the main body and attached to
the driven body.