Openable roof

An openable roof includes a plurality of movable roof members. Each of the movable roof members is of a generally sectorial shape in two-dimensional projection. The sectorial shape has a radially outer edge portion and a radially inner edge portion. The outer edge portion of the movable roof member is movably disposed on an outer arcuate support. The inner edge portion of the movable roof member is movably disposed on an inner arcuate support. The outer and inner arcuate supports are disposed concentrically about a common axis. Accordingly, each of the movable roof members is able to revolve around the axis of the arcuate supports so as to participate to open and close a sectorial opening portion provided between the arcuate supports.

BACKGROUND OF THE INVENTION 
The present invention relates to an openable roof comprising a plurality of 
slidable (movable) roof members which are of partially sectorial shape 
when viewed from above, and which are arcuately movable along a prescribed 
arcuate path about a central axis of rotation. 
In compliance with the duty of disclosure, the present applicant discloses 
four U.S. patent applications, Ser. Nos. 07/439,302, 07/502,170, 
07/502,613, and 07/523,720. 
Openable roofs are highly desirable as they provide sunlight, fresh air, 
and a sense of freedom when open, while protecting the interior from 
adverse weather when closed. To this end, various types of openable roofs 
were previously proposed and developed. 
However, most of the openable roofs involve the following problems: 
The configurations of the movable roof members and the travelling 
mechanisms for travelling the members are complicated. In openable roofs, 
the portion of the opening is necessarily narrow, and the support for 
supporting the movable roof members must withstand a highly concentrated 
load from the movable roof members. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide an openable 
roof wherein the configurations of the movable roof members, and the 
travelling mechanisms for travelling the members, are simplified. 
Another object of the invention is to provide an openable roof wherein the 
portion of the opening is relatively broad. 
A further object of the invention is to provide an openable roof wherein 
the load from the movable roof members is effectively distributed. 
In order to achieve the above objects, the openable roof in one aspect of 
the invention includes a plurality of movable roof members. Each of the 
movable roof members is of a generally sectorial shape in two-dimensional 
projection. The sectorial shape has a radial outer edge portion and a 
radial inner edge portion. The outer edge portion of the movable roof 
member is movably disposed on an outer arcuate support. The inner edge 
portion of the movable roof member is movably disposed on an inner arcuate 
support. The outer and inner arcuate supports are disposed concentrically 
about a common axis. Accordingly, each of the movable roof members is able 
to revolve around the axis of the arcuate supports so as to participate in 
the opening and closing of a sectorial opening portion provided between 
the arcuate supports. 
With the above construction, the configuration of the movable roof members, 
and the travelling mechanisms for travelling the members, can be 
simplified and made compact. Accordingly, the cost of constructing the 
roof members and the travelling mechanisms is decreased. 
Additionally, since the movable roof members are disposed on the arcuate 
tracks, the load from the movable roof members is effectively distributed 
on the tracks. Consequently, the stability of the whole roof structure can 
be improved. 
Furthermore, by virtue of the inner arcuate support, there is provided a 
sectorial space defined by the inner support. Accordingly, the area 
wherein the structure is built can be relatively small. Thus, the cost of 
the land for the structure with the openable roof is reduced. 
Alternatively, the space saved can be utilized for other purposes. 
Moreover, since the roof members are supported on the pair of arcuate 
supports, the length of the roof members, along the radial direction of 
the arcuate shape thereof, can be compact. Hence, the bending moment 
exerted on each of the roof members can be decreased. The roof members can 
be designed so that the mechanical strength thereof is relatively small 
and the weight thereof is also small. Accordingly, the cost of 
constructing the roof members and the travelling mechanisms is decreased. 
More preferably, the openable roof further comprises at least one fixed 
roof member which is disposed at a side of the sectorial opening. Each 
fixed roof member is of a generally sectorial shape in two-dimensional 
projection. Each of the sectorial shapes has a radially outer edge portion 
and a radially inner edge portion. The outer edge portion of the fixed 
roof member is fixedly disposed on an outer arcuate support. The inner 
edge portion of the fixed roof member is fixedly disposed on an inner 
arcuate support so that the movable roof member is able to be stored under 
the fixed roof member when the roof is open. 
In this case, since the movable roof members are stored under the fixed 
roof members when the roof is open, the portion of the opening is broader 
than that of conventional openable roofs. This heightens the sense of 
openness that people in the structure can feel. 
More preferably, each of the fixed and the movable roof members comprises a 
section of a sphere, with a subsection removed, so that the entire 
openable roof is dome-shaped when the roof is closed. 
More preferably, a pair of said fixed roof members are provided at both 
sides of the sectorial opening. 
More preferably, a plurality of drive means are provided under the outer 
and inner edge portions of the movable roof members whereby the movable 
roof members are movably and drivingly supported on the arcuate supports 
via the drive means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to the accompanying drawings, various preferred embodiments 
of the present invention will be described in detail hereinafter. 
First Embodiment 
An openable roof 20 according to a first embodiment is represented in FIGS. 
1 through 5. As shown in FIGS. 1 through 4, the openable roof 20 is 
disposed on a multipurpose stadium 22 in which baseball games may be 
played, concerts performed, and so on. 
The openable roof 20 is generally of partially sectorial shape in plan view 
when the roof is closed. The openable roof 20 comprises four separate 
movable roof members (panels) 24 and 25 (24a, 24b, 25a, and 25b), and a 
pair of fixed roof members (panels) 26. Each of the movable and fixed roof 
members 24, 25, and 26 is also of a partially sectorial shape in plan 
view, so that the roof members 24, 25, and 26 cooperate to close off the 
stadium 22 from the outer environment. Also, each of the movable roof 
members 24a, 24b, 25a, 25b forms a central angel smaller than the central 
angle of the openable roof 20. Each of the movable and fixed roof members 
24, 25, and 26 is of an arc shape in side view (FIGS. 3 and 4), so that 
the openable roof 20 is of a dome shape, that is, generally a portion of a 
sphere, when the roof 20 is closed. 
As shown in FIGS. 1 and 2, the fixed roof members 26 are disposed on both 
of the sides (wings) of the roof 20. When the roof 20 is closed off, the 
movable roof members 24 and 25 intermediate between both the fixed roof 
members 26. For clarity, the movable roof members 24 and 25 are classified 
into a pair of right wing movable roof members 24 and a pair of left wing 
movable roof members 25. 
In FIG. 1, the right wing movable roof members 24 and the left wing movable 
roof members 25 are symmetrically disposed about the center line 28 of the 
stadium 22. Each of the movable roof members 24 and 25 are slidably turned 
about the center axis 30 of the partially sectorial roof 20. Therefore, 
both of the right wing movable roof members 24 are lapped under the right 
wing fixed roof member 26 when the roof is closed off as shown in FIG. 2. 
Similarly, both the left wing movable roof members 25 are lapped under the 
left wing fixed roof member 26. 
As shown in FIGS. 1 through 4, the movable and fixed roof members 24, 25, 
and 26 are supported on a pair of arcuate supports 32 and 34. The arcuate 
supports 32 and 34 are disposed in the same horizontal plane, and are 
disposed on the wall of the stadium 22. The radially outer arcuate support 
32 and the inner arcuate support 34 are concentrically disposed in such a 
fashion that the above-mentioned center axis 30 is the common center of 
the supports 32 and 34. 
The radially outer arcuate edges 36 of the movable roof members 24 and 25 
are slidably disposed on the outer arcuate support 32. The radially inner 
arcuate edges 38 of the movable roof members 24 and 25 are also slidably 
disposed on the inner arcuate support 34. Accordingly, each movable roof 
members 24 and 25 can perform its own turning motions. 
As best shown in FIG. 3, the shape of each of the roof members 24, 25, and 
26 is a portion of a sphere, the outer surface of which forms a generally 
continuous smooth curved surface when the roof is closed. However, the 
imaginary diameters of the roof members are slightly different from one 
another. That is, the imaginary diameter of the fixed roof members 26 is 
the greatest since the movable roof members 24 and 25 are stored under the 
fixed roof members 26 when the roof 20 is open. 
In order to clarify this, the movable roof members 24 and 25 are classified 
into central movable roof members 24a and 25a, and side movable roof 
members 24b and 25b, hereinafter. The central movable roof members 24a and 
25a may cover the central part of the stadium 22. The side movable roof 
members 24b and 25b may cover the sides of the stadium 22. The central 
right wing and the central left wing movable roof members 24 (24a) and 25 
(25a) have the same imaginary diameter. The side right wing and left wing 
movable roof members 24 (24b) and 25 (25b) have the same imaginary 
diameter. The imaginary diameter of the central movable roof members 24a 
and 25a is greater than that of the side movable roof members 24b and 25b, 
so that the travelling paths of the central and side movable roof members 
24a and 25a do not interfere with each other, and 24b and 25b do not 
interfere with each other. Consequently, the central movable roof members 
24a and 25a are disposed over the side movable roof members 24b and 25b 
when the roof 20 is open. 
A pair of rail-like tracks 40 and 42 are installed on the upper surface of 
the radially outer arcuate support 32, and continuously along the support 
32. Similarly, a pair of rail-like tracks 44 and 46 are installed on the 
surface of the radially inner arcuate support 34, and continuously along 
the support 34. The tracks 40, 42, 44, and 46 are disposed in the same 
horizontal plane. 
A plurality of electrically driven wheels 48, for example, 
servo-linear-motor-driven wheels, are connected to the lower surfaces of 
the arcuate edges 36 and 38 of the movable roof members 24 and 25, and 
drivingly disposed on the tracks 40, 42, 44, and 46 of the radially outer 
and inner arcuate supports 32 and 34. 
As best shown in FIGS. 1 and 5, the central movable roof members 24a and 
25a are slidably supported on the tracks 40 and 44. The side movable roof 
members 24b and 25b are also slidably supported on the tracks 42 and 46 in 
order to avoid interference between the central and side movable roof 
members. On the other hand, the fixed roof members 26 are fixedly secured 
on the supports 32 and 34. 
Next, the operation and function of the above-described openable roof 10 
will be explained hereinafter. 
As shown in FIG. 1, when the roof 20 is closed, the central movable roof 
24a and 25a are disposed above the center portion of the stadium 22, and 
the side movable roof 24b and 25b are disposed above the relatively sides 
of the stadium 22. The fixed roof members 26 are always disposed above the 
right and left wings. The roof members 24, 25, and 26 are slightly 
overlapped one over the other. Therefore, the interior area of the stadium 
22 is closed off. 
In order to open the roof 20, the right wing movable roof members 24 are 
respectively traveled along their own paths indicated by the arrow in FIG. 
1, by means of the drive for the wheels 48. The rotational motion of the 
movable roof members 24 is stopped when the roof members 24 reach the 
right most wing 52 of the stadium 22. Accordingly, the right wing movable 
roof members 24 are disposed and stored under the right wing fixed roof 
member 26. Similarly, the left wing movable roof members 25 are disposed 
and stored under the left wing fixed roof member 26 at the left-most wing 
54. Thus, an open area defined by both of the fixed roof members 26 is 
opened, exposing the interior, as shown in FIG. 2. 
When closing off the movable roof, the reverse motions of the movable roof 
members 24 and 25 may be performed. 
Since the widths as well as the horizontal angles of the movable roof 
members 24 and 25 are designed to be consistent in this embodiment, the 
central and side movable roof members 24a, 24b, 25a and 25b simultaneously 
reach the right-most or left-most wing if the central movable roof members 
24a and 25a are driven at a angular velocity which is double that of the 
right or left-side movable roof members 24b and 25b. 
If the angular velocities of all the roof members 24 and 25 are the same, 
first, the relative location of the central and the side roof members 24a 
and 24b (or 25a and 25b) are kept as in the closed position when 
travelling. However, the side movable roof members 24b and 25b reach the 
side-most wings 52 or 54, before the central movable roof members 24a and 
25a. Then, the central movable roof members 24a and 25a travel alone until 
they reach the side-most wings 52 or 54. 
With the above construction, the configuration of the movable roof members 
24 and 25, and the travelling mechanisms (including the tracks 40, 42, 44, 
and 46 and the electrically driven wheels 48) for travelling the members, 
can be simplified and made compact. Accordingly, the costs of constructing 
the roof members and the travelling mechanisms is decreased. 
In addition, since the movable roof members 24 and 25 are stored under the 
fixed roof members 26 when the roof 20 is open, the portion of the opening 
is broader than that of conventional openable roofs. This heightens the 
sense of openness and freedom experienced by the audience in the stadium 
22. 
Additionally, since the movable roof members 24 and 25 are disposed on the 
arcuate tracks 40, 42, 44, and 46, the load from the movable roof members 
24 and 25 is effectively distributed on the tracks. Consequently, the 
stability of the whole roof structure 20 is improved. 
Furthermore, by virtue of the inner arcuate support 34, there is provided a 
sectorial space 56 defined by the support 34 and the dotted lines in FIGS. 
1 and 2. Accordingly, the area wherein the stadium 22 is built can be 
relatively small. Thus, the cost of the land on which the stadium 22 is 
built is reduced. Alternatively, the space 56 can be utilized for other 
purposes. 
Moreover, since the roof members 24, 25, and 26 are supported on the pair 
of arcuate support 32 and 34, the length of the roof members 24, 25, and 
26, along the radial direction of the arcuate shape thereof, can be 
compact. Hence, the bending moment exerted on each of the roof members 24, 
25, and 26 can be decreased. The roof members can be designed so that the 
mechanical strength thereof is relatively small and the weight thereof is 
also small. Accordingly, the cost of constructing the roof members and the 
traveling mechanisms is decreased. 
Although a first preferred embodiment of the present invention is described 
hereinbefore, the present invention is not intended to be limited to the 
first embodiment. Other embodiments in accordance with the spirit and 
objects of the invention will be described in the following. 
Second Embodiment 
FIGS. 6-8 depict a second embodiment of the present invention. In the first 
embodiment, the tracks 40, 42, 44, and 46 are disposed in the same 
horizontal plane. In contrast, as best shown in FIG. 8, in the second 
embodiment, a step may be provided between the level of the track 44 and 
the level of the track 46. The movable roof members 24 and 25 are slidably 
disposed on the tracks 44 and 46 via the electrically driven wheels 48 in 
a manner similar to those in the first embodiment. Although FIG. 8 depicts 
only the tracks 44 and 46, the tracks 40 and 42 may be similarly formed. 
Third Embodiment 
FIGS. 9 and 10 depict a third embodiment of the present invention. In the 
third embodiment, each of the arcuate supports 32 and 34 comprises four 
steps on the upper face thereof. On each of the steps, each of tracks 58 
is installed along the arcuate shape of the corresponding supports 32 or 
34. The movable roof members 24a, 24b, 25a, and 25b are slidably disposed 
on the tracks 58 via the electrically driven wheels 48 in a manner similar 
to those in the first embodiment. 
In the third embodiment, when the roof 20 is open, all of the movable roof 
members 24a, 24b, 25a, and 25b can be stored under either of the fixed 
roof members 26 which are disposed on the outermost wings of the roof 20. 
Off course, the right wing and left wing movable roof members 24 and 25 
may be stored under the fixed roof members 26 separately, in the same 
manner as in the first embodiment.