Abstract:
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.

Description:
This is a continuation of copending application Ser. No. 567,134 filed on Aug. 14, 1990 now abandoned. 
    
    
     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. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of an openable roof according to a first embodiment of the present invention, showing the roof in the closed configuration. 
     FIG. 2 is a plan view of the openable roof in FIG. 1, when the is in the open configuration. 
     FIG. 3 is a side view of the openable roof in FIG. 1, showing a side indicated by arrow III in FIG. 1. 
     FIG. 4 is a side view of the openable roof in FIG. 1, showing a side indicated by arrow IV in FIG. 1. 
     FIG. 5 is a plan view of the support tracks for supporting the movable roof members of the openable roof in FIG. 1, and on which the movable roof members travel. 
     FIG. 6 is a simplified plan view of an openable roof according to a second embodiment of the present invention, showing the roof in the closed configuration. 
     FIG. 7 is a side view of the openable roof in FIG. 6, showing a side indicated by arrow VII in FIG. 6. 
     FIG. 8 is a side cross-sectional view of the support tracks for supporting the movable roof members of the openable roof in FIG. 6, and on which the movable roof members travel. 
     FIG. 9 is a plan view of an openable roof according to a third embodiment of the present invention. 
     FIG. 10 is a side cross-sectional view of the support tracks for supporting the movable roof members of the openable roof in FIG. 9, and on which the movable roof members travel. 
    
    
     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.