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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a retractable screen that is installed in the opening portion of a building for the purpose of insect-proofing, light-shielding, heat insulation, and as a blind, and specifically relates to an improved retractable screen device wherein, by cutting edge portions for the upper and lower frame material and the right and left side frames in an arbitrary length, and using corresponding corner linking material to link these together, the dimensions can be easily made to fit the opening portion of a building even if the user is not well-practiced in this skill. 
   2. Discussion of the Background 
   In general, retractable screen devices have been widely known that are installed in an opening portion of a building for the purpose of insect-proofing, light-shielding, heat insulation, shading, and so forth. In the case of installing such retractable screen devices in the opening portion of a building, the screen frame needs to be of the dimensions that fit with the size of the opening, and this dimension fitting is performed by cutting the upper and lower frame material and the left and right side frames in the necessary length corresponding to the aforementioned opening portion dimensions, and linking the edge portions of the upper and lower frame material and the left and right side frames with corresponding corner linking material. 
   However, if the dimension fitting is only for this type of screen frame, the user and others can perform this relatively easily, and therefore the necessary materials and parts can be sold as a set, but in the case of a screen device that comprises a winding mechanism wherein the screen is wound on to a winding shaft using a spring for winding, the assembly of the winding mechanism is not necessarily simple, and also latter-described problems may occur, and therefore the user must either obtain a product that fits the dimensions of the building opening portion, or hire a professional worker for the dimension adjustment work. 
   In other words, with the screen device described above which enables dimension fitting, the upper and lower frame material is shortened according to the width of the building opening portion, and the length of the screen to be pulled out is shortened accordingly, resulting in not only the necessity to adjust the strength of the winding spring, but the remaining screen is in the state of being wound on the winding shaft even in the state wherein the screen is spread over the screen frame, and therefore the screen can bend widely due to the wind or other external forces, and it becomes necessary to consider countermeasures. 
   In particular, in the case that a winding shaft is provided on the left and right side frames and the screen is open both on the left and right sides, the winding shaft that winds each screen has an additional screen wound onto it, and therefore in the case of pulling out each screen to spread them, only enough screen to cover half of the building opening width needs to be pulled out, but because of the additional allowance in the length of the screen, the screen can possibly be pulled out further than the pullout limit, and a countermeasure becomes necessary, such as the user keeping this in mind at the time of use, or providing a stopper to set the pullout limit. 
   Further, in the case that the length of the screen has an additional allowance and the screen is pulled out more than necessary due to an external force such as the wind and bends widely, the upper and lower edges of the screen can be derailed from the guide grooves of the upper and lower frame, and if the screen is wound onto the winding shaft in this state, one portion of the screen is over the guide groove wall, and so from this portion on is wound in a wrinkled state and opening and closing of the screen thereafter is not smooth. Therefore, the appropriate setting of the above-described screen unwinding limit is important, but even with such settings the upper and lower edges of the screen may be derailed from the guide grooves, and therefore consideration is necessary for the screen to be wound smoothly even in the case of derailing. 
   DISCLOSURE OF INVENTION 
   A technical object of the present invention is to provide a retractable screen device wherein a retractable screen device equipped with a winding mechanism for propagating the pressure force of the spring for winding the screen to this winding shaft is installed in the opening portion of a building, in which case the upper and lower frame material and the right and left side frames of the screen frame are cut to the necessary lengths corresponding to the aforementioned opening portion dimensions, and the dimensions fitting the size of the opening portion are easily adjustable. 
   Another technical object of the present invention is to provide a retractable screen device wherein the retractable screen device is equipped with a winding device, and when the dimensions of the upper and lower frame material and the right and left side frames of the screen frame are adjusted to correspond with the aforementioned opening portion dimensions, the adjustment of the winding force of the aforementioned winding mechanism and the setting of the limits for pulling out the screen can be performed easily. 
   Another technical object of the present invention is to provide a retractable screen device wherein the screen can be wound smoothly even if the upper and lower edges of the screen derail from the guide grooves. 
   Yet another technical object of the present invention is to provide convenience in both the manufacturing and assembling of the above-described retractable screen device as much as possible. 
   With a retractable screen device according to the present invention for solving the aforementioned problems, a screen frame is configured by cutting edge portions for the upper and lower frame material and the right and left side frames in an arbitrary length, and using corner linking material to link these by alternately attaching these linking portions, one edge of the screen if a single screen, and one edge from each side for a screen that opens to both the left and right, to be spread within this frame is wound onto the winding shaft provided on one side of the aforementioned side frame, and the other edge of this screen is linked to a movable rail that is guided by the frame body of the aforementioned upper and lower units; wherein a winding mechanism is provided on one side of the corner linking material of both edges of the side frame providing the aforementioned winding shaft, so as to be capable of insertion into or removal from the winding shaft, to which the pressing force of an adjustable spring for linking to the winding shaft and winding the screen to this winding shaft is propagated; and a stopper mechanism is provided on the other side of the aforementioned linking material, so as to be capable of insertion into or removal from the winding shaft, wherein the limit of the screen unwinding by the rotation of the winding shaft is adjustable. 
   With the winding mechanism according to the above retractable screen device, a spring receptacle on the base edge side for inserting into the winding shaft and a spring support shaft that is fixed thereupon is provided to the corner linking material via a clutch mechanism, and while one edge of the winding spring is wound and fixed to the aforementioned base edge side spring receptacle, the other edge of the spring wound and fixed to the winding shaft side spring receptacle provided on the spring support shaft so as to be capable of rotating, and the spring receptacle on this winding shaft side rotates integrally with the winding shaft, but is attached to the winding shaft in the axial direction of the winding shaft so as to be capable of moving; wherein the aforementioned clutch mechanism prevents the base edge side spring receptacle from rotating due to the spring pressing force, but the rotation of the operation ring provided on the corner linking material can be propagated to the spring support shaft for the purpose of adjusting the pressing force of the spring for winding the screen. 
   Further, with the stopper mechanism according to the aforementioned retractable screen device, the screw shaft for inserting the corner linking materials into the winding shaft is linked via the clutch mechanism, and a nut that rotates integrally with the winding shaft but is capable of moving in the axial direction is screwed in to this screw shaft, and a stopper for setting the limit of the nut advancing is provided on the aforementioned screw shaft, and is configured so that when the winding shaft is rotated in the screen unwinding direction the nut advances along the screw shaft towards the stopper; and the aforementioned clutch mechanism prevents rotation of the screw shaft from rotating due to the rotational force of the winding shaft and so forth, but the rotation of the operation ring provided on the corner linking material can be propagated to the screw shaft for the purpose of adjusting the limit of the screen unwinding. 
   With the retractable screen device that has the aforementioned configuration, the upper and lower frame material and the right and left side frames of the screen frame are cut to the necessary lengths to correspond with the dimensions of the building opening portion, and by mutually fitting and linking these edge portion to the portions linking with corner linking material, a screen frame can be configured wherein the dimension thereof fits the size of the building opening portion, and this is equipped with a winding mechanism for winding the screen by pressing force of a spring, wherein this winding mechanism is provided on the corner linking material of one edge of the side frame on which is provided the aforementioned winding shaft, and because this can be inserted or removed from the winding shaft, even if the side frame equipped with the winding shaft is adjusted to an arbitrary length, the assembly of the winding mechanism to the screen frame can be performed easily. 
   Additionally, this winding mechanism is adjustable from the outside after assembling the spring pressing force for winding the spring, because of the operating ring provided on the corner linking material, and therefore, even if the screen frame dimensions are set arbitrarily, the screen winding force on the winding shaft can be set appropriately. 
   Further, on the other side of the aforementioned corner linking material a stopper mechanism is provided that is capable of adjusting the limit of screen unwinding by the rotation of the winding shaft, and therefore by performing the appropriate adjustments thereof, even if the length of the upper and lower frame material is arbitrarily set, the additional allowance of the screen that is wound onto the winding shaft will not widely bend due to the wind or another external force, and even in the case that the screen opens to both the left and right by providing winding shafts on the left and right side frames, the additional screen will not be pulled out more to cover more than ½ the area of the building opening width. Further, the aforementioned stopper mechanism is capable of adjusting the screen unwinding limit arbitrarily from the outside by the operating ring provided on the corner linking material, and therefore, even if the dimensions of the upper and lower frame material are set arbitrarily, the appropriate unwinding length can be easily set. Further, by providing this stopper mechanism, the length of the screen does not need to be cut short to fit with the dimensions of the upper and lower frame material when assembling the screen device. 
   Additionally, the stopper mechanism is provided on the corner linking material so as to be capable of inserting into or removing from the winding shaft, and therefore similar to the case of the aforementioned winding mechanism, even if the side frames are adjusted to an arbitrary length, the assembly of the stopper mechanism to the screen frame can be performed easily. 
   With the aforementioned retractable screen device, guide grooves are provided to guide the upper and lower edges of the screen along the upper and lower frame material, and an extension portion for the aforementioned guide groove is provided on the corner linking material that is positioned on the upper and lower edges of the side frame equipped with the winding shaft, and a guide groove for returning the screen derailed from the guide groove when winding the screen on to the winding shaft into the extension portion in the groove wall wherein the extension portion is configured is provided along the winding width of the screen on the winding shaft, which is effective for winding the screen that is pulled out from the guide groove smoothly onto the winding shaft so as not to have any wrinkles, and at the same time for returning the screen derailed from the groove back into the correct position along with the winding. 
   Further, with the aforementioned retractable screen device, by making the left and right side frames and the rail material for the movable rail and the winding shaft for the screen the same length, and also making the upper and lower frame material the same length, a movable rail that fits the screen frame can be formed, or alternatively, making the upper and lower frame material common, the corner linking material of the upper and lower material is formed vertically symmetrically, except for the winding mechanism and the stopper mechanism, wherein both edges of the winding shaft are supported by the supporting face of the corner linking material via a washer, so as to be capable of rotating, and the screen frame can be used when turned upside down, and thus is effective when considering the convenience of manufacturing, assembly, and construction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a disassembled perspective view illustrating a first embodiment of a retractable screen device relating to the present invention. 
       FIG. 2  is a partial cutaway frontal view of the embodiment. 
       FIG. 3  is a plan cross-sectional view of the embodiment. 
       FIG. 4  is an enlarged cross-sectional view of the principal portions of the corner linking material having a winding mechanism. 
       FIG. 5  is a plan cross-sectional view illustrating a second embodiment of a retractable screen device relating to the present invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1  through  FIG. 4  illustrate one embodiment wherein a retractable screen device relating to the present invention is used as an insect-prevention screen door, and this retractable screen device includes a screen frame  1  that comprises upper and lower frame material  2  and  3  and left and right side frames  4  and  5 , which are linked with corner linking material  6 ,  7 ,  8 , and  9 . The aforementioned upper and lower frame material  2  and  3  are configured with a fixed cross-section by using a common extrusion material of such as aluminum or plastic, and can be cut to an arbitrary length to fit the opening width of the building opening portion. 
   Further, the above-mentioned pair of side frames  4  and  5  are an example of the illustrated state of the screen device with one side being opened, and the one side frame  4  comprises a winding box that houses a winding shaft  12  of a screen  11 , and the other edge of the screen  11  wherein one edge is fixed on this winding shaft  12  is fixed to a movable rail  13  that guides the upper and lower frame body  2  and  3 , and by moving this movable rail  13  to the position of the side frame  5  on the other end, the screen  11  is spread across the entirety of the screen frame  1 . With the screen device thus configured, the aforementioned one side frame  4  only is configured as the winding box, and the other side frame  5  is configured as the rail receptacle that receives the movable rail  13  when the screen is spread. However, in the case to be described below, wherein both sides are opened, both side frames  4  and  5  are configured as winding boxes. 
   By linking the edge portions of the upper and lower frame material  2  and  3  and the right and left side frames  4  and  5  that are cut to an arbitrary length with the corresponding corner linking materials  6  through  9 , the aforementioned screen frame  1  is configured. The upper and lower corner linking material  6  and  8  that link the space between the aforementioned upper and lower frame material  2  and  3  and the upper and lower edges of the side frame  4  that make up the winding box are formed to be vertically symmetrical, except for the winding mechanism  20  and the stopper mechanism  40  to be described below that are linked thereto, and the linking of the corner linking material  6  and  8  and the side frame  4  is made by fitting and abutting linking portions  4   a  and  4   b  of the upper and lower edges of the side frame  4  to linking portions  6   a  and  8   a  that are on the corner linking material  6  and  8 , and fastening with screws  16  from the upper and lower edges. Further, the corner linking material  6  and  8  and the upper and lower frame material  2  and  3  are linked, as clearly illustrated in  FIG. 1 , by fitting and abutting linking portions  6   b  and  8   b  of the corner linking material  6  and  8  to the linking portions  2   a  and  3   a  on the end portions of the upper and lower frame material  2  and  3 , and fixing as necessary with screws and so forth. 
   On the other hand, the upper and lower corner linking material  7  and  9  that link the upper and lower frame material  2  and  3  and the side frame  5  that comprises a rail receptacle is formed to have an vertical symmetrical form, and similar to the case of linking the aforementioned corner linking material unit  6  and  8  and the side frame  4 , the linking of the corner linking material  7  and  9  and the side frame  5  is linked by fitting and abutting the linking portions  5   a  and  5   b  of the upper and lower edges of the side frame  5  to the linking portions  7   a  and  9   a  that are on the corner linking material  7  and  9 , and fastening with the screws  16  from the upper and lower edges. Further, the corner linking material  7  and  9  and the upper and lower frame material  2  and  3  are linked by fitting the linking portions  7   b  and  9   b  of the corner linking material  7  and  9  up against the linking portions  2   a  and  3   a  on the end portions of the upper and lower frame material  2  and  3 , and fixing as necessary with screws and so forth. 
   Further, regarding the movable rail  13 , similar to the side frames  4  and  5 , a rail material  14  of a fixed cross-section is cut to the necessary length, and is configured by providing caps  15   a  and  15   b  to slide along the guide groove formed in the upper and lower frame material  2  and  3  on both sides. Now, this movable rail  13  is provided with a latch  18  on the concave portion of the side frame  5  that comprises the rail receptacle in the center position for retaining elastically. 
   The aforementioned left and right side frames  4  and  5  and the rail material  14  of the movable rail  13  and the aforementioned screen winding shaft  12  are formed to the same length, and thus the necessary screen frame  1  and the movable rail  13  that applies thereto is designed, and further, the screen frame is formed with the same length of the upper and lower frame material  2  and  3 . Therefore, by cutting these raw materials to the same fixed length that correspond to the dimensions of the building opening portion with an appropriate cutting tool or a cutting device, the screen frame  1  with the predetermined size can be assembled. 
   The corner linking material  6  on the upper side of the side frame  4  that has the aforementioned winding shaft  12  is provided with a winding mechanism  20  that is capable of insertion to or removal from the winding shaft  12 , and the corner linking material  8  on the lower side is provided with a stopping mechanism  40  that is capable of insertion to or removal from the winding shaft  12 . 
   The aforementioned winding mechanism  20  is linked to the winding shaft  12  that supports the corner linking material  6  and  8  on both edges of the side frame  4  so as to be capable of rotating, and is to propagate the pressing force of a spring  25  for winding the screen  11  to the winding shaft  12 , and the aforementioned stopping mechanism  40  is capable of adjusting the unwinding limit of the screen  11  by the rotation of the winding shaft  12 . 
   The configurations of winding mechanism  20  and the stopper mechanism  40  will be described in detail below. 
   First, the corner linking material  6  equipped with the winding mechanism  20  on one edge of the side frame  4  housing the aforementioned winding shaft  12  is equipped with an end cover  22  assembled to a linking material main unit  21  and fixed with screws. The aforementioned end cover  22  forms a room  23  that houses an operating ring  24  between the linking material main unit  21 , but an opening portion can be formed by notching out one portion thereof (see  FIG. 1 ), and the operating ring  24  can be rotated and operated from the outside with the fingertips. Further, on the inside of the operating ring  24  that is in the aforementioned room  23 , a clutch mechanism  30  is also housed, and a clutch cylinder  22   a  that forms one portion of the clutch mechanism  30  is formed integrally on the inner face side of the end cover  22  (see  FIG. 4 ). 
   The winding mechanism  20  is equipped with a linking shaft  26  that links to the clutch cylinder  22   a  of the end cover  22 , via a clutch mechanism  30  described below, and a spring support shaft  28  that is fixed to the linking shaft  26  and inserted into the winding shaft  12 ; and provides a spring receptacle  27  as one unit that is fixed on the front edge side of the linking shaft  26 , and on the spring support shaft  28  a spring receptacle  29  on the winding shaft side that is linked to the inner face of the winding shaft  12  is supported so as to be capable of rotating, and both edges of the winding spring  25  are wound and fixed on to the spring receptacles  27  and  29 . 
   The spring receptacle  29  on the winding shaft side rotates integrally with the winding shaft  12  by spline engaging and so forth, but is capable of movement in the axial direction of the winding shaft  12 . Therefore, the winding shaft  12  is linked to the linking shaft  26 , via the spring  25 , that is provided in a fixed manner to the corner linking material  6  via the clutch mechanism  30 , and the pressing force in the winding direction of the winding shaft  26  is provided by this spring  25 . 
   The aforementioned clutch mechanism  30  is such that the linking shaft  26  is prevented from rotating by the rotational force from the winding shaft  12  side by linking the linking shaft  26  to the clutch cylinder  22   a  of the end cover  22  of the corner linking material  6  by the clutch mechanism  30 , the rotation of the operating ring  24  that borders on the opening portion of the end cover  22  is propagated to the spring receptacle  29  via the linking shaft  26  and the spring support shaft  28  for the purpose of adjusting the pressing force of the spring  25  for winding the screen  11 . 
   In other words, the spring receptacle  29  can be rotated in either forward or backward directions by operating the operating ring  24 , and the rotation of this spring receptacle  29  twists the spring  25  while rotating the winding shaft  12 , and is capable of adjusting the pressing force of the spring  25 . 
   Next, the configuration of the aforementioned clutch mechanism  30  will be described in detail. 
   The clutch cylinder  22   a  provided on the inner face of the end cover  22  of the aforementioned corner linking material  6  has a clutch spring  31  wound thereupon that is pressed in the direction of reduction in diameter, and pressured against the surface of the clutch cylinder  22   a , forming bent portions  31   a  each facing the ends of the clutch spring  31 . On the other hand, on the base end of the linking shaft  26  is provided a cylinder unit  32  that is supported within the clutch cylinder  22   a  so as to be capable of rotating, and a pair of protruding portions  33  that protrude in the surrounding area of the clutch spring  31  that is wound on to the clutch cylinder  22   a , and further, the operating ring  24  is rotatably fit to the circumferential face of the protruding portions  33 , with the engaging protruding portion  24   a  provided in a protruding manner being introduced on the inner face of this operating ring  24  so as to allow sufficient space between the pair of protruding portions  33 . 
   Further, the pair of bent portions  31   a  of the clutch spring  31  is positioned on both sides of the engaging protruding portion  24   a  provided in a protruding manner from the operating ring  24 , between the protruding portion  33  provided on the base unit of the linking shaft  26 . The aforementioned clutch spring  31  is pressed in the diameter reduction direction within the circumference of the clutch cylinder  22   a , but the direction for the engaging protruding portion  24   a  to press on either of the pair of bent portions  31   a  of the clutch spring  31 , by the rotation of the operating ring  24 , is the direction in which the winding diameter of the clutch spring  31  becomes larger and the winding is released toward the clutch cylinder  22   a.    
   Therefore, by rotating the operating ring  24  on the aforementioned clutch mechanism  30  in either direction, one of the bent portions  31   a  of both edges of the clutch spring  31  is engaged with the engaging protruding portion  24   a  provided on the inner face of the operating ring  24 , and the bent portion  31   a  is moved in the direction that the winding diameter of the clutch spring  31  becomes larger. Therefore, the friction between the clutch spring  31  and the clutch cylinder  22   a  is reduced, and the operating ring  24  rotates while pressing down on the protruding portion  33  of the base unit of the linking shaft  26  by the engaging protruding portion  24   a , and that rotation is propagated to the linking shaft  26  and propagated to the spring receptacle  29  via the spring support shaft  28 . 
   Thus, even if the rotational force acts upon the linking shaft  26  due to the rotation force and so forth of the winding shaft  12 , the direction that the protruding portion  33  of the linking shaft base unit presses on one of the pair of the bent portions  31   a  of the clutch spring  31  is the direction to make the winding diameter of the clutch spring  31  smaller and strengthen the winding towards the clutch cylinder  22   a , and therefore, the linking shaft  26  is fixed onto the aforementioned end cover  22  on the corner linking material  6 , and the rotational force is not propagated to the operating ring  24 . 
   Further, between the aforementioned spring support shaft  28  and the winding shaft  12  is provided an oil damper  35  that houses a one-directional clutch mechanism. The linking of the oil damper  35  and the spring support shaft  28  is done similar to the aforementioned case of the spring receptacle  29 , wherein the oil damper  35  rotates integrally with the winding shaft  12  by spline engaging and so forth, but is capable of moving in the axial direction of the winding shaft  12 . 
   The one-directional clutch mechanism is such that, in the case of rotating the winding shaft  12  in the direction of spreading the screen  7  against the rotational pressing force of the spring  25 , the connection between the spring support shaft  28  and the winding shaft  12  is automatically severed, and when the winding shaft rotates in the opposite direction the winding shaft  12  is linked to the spring support shaft  28  via the oil damper  35 . 
   The oil damper  35  can be configured so as to comprise a casing that is linked to the spring support shaft  28 , and a damping cylinder that propagates the rotation via a viscous fluid inside this casing, with the damping cylinder linked to the winding shaft  12  via a known one-directional clutch mechanism, but an arrangement with another appropriate construction may also be used. 
   Such an oil damper  35  is effective in damping the impact of the movable rail  13  colliding with the corner linking material  6 , and preventing the collision sound thereof when rewinding the screen  11  with the winding spring  25 , but this does not necessarily need to be provided. 
   The winding mechanism  20  provided on the aforementioned corner linking material  6  has the linking shaft  26 , the spring support shaft  28 , the spring receptacle  29 , and the oil damper  35 , inserted within the winding shaft  12 , but the aforementioned spring receptacle  29  and the oil damper  35  is engaged and inserted into the winding shaft  12  by spline engaging or the like, and therefore, the winding shaft  12  and the corner linking material  6  and the winding mechanism  20  are linked so as to be detachable. 
   Specifically, the edge portions of the winding shaft  12  are supported on the circumference of the linking shaft  26  so as to be capable of rotating, and in this instance, a washer  36  is placed between the shaft edges of the winding shaft  12  and the support face that receives the winding shaft edges on the linking material main unit  21  within the corner linking material  6 , and supports the edge portions of the winding shaft so as to be capable of rotating. 
   Next, the aforementioned stopper mechanism  40  that sets the limit for unwinding of the screen  11  provided on the corner linking material  8  will be described. 
   This stopper mechanism  40  is inserted into the winding shaft  12  via a clutch mechanism  50  towards the corner linking material  8 , and rotatably links the support shaft  41  that support the edge portions of the winding shaft  12  and the screw shaft  42  that protrudes from the front edge thereof, and is screwed to this screw shaft  42  with a nut  43  that rotates integrally with the winding shaft  12  but that is capable of moving in the axial direction of the winding shaft  12 . Further, the aforementioned screw shaft  42  is equipped with a stopper  44  that fixes the limit of the nut  43  for screwing towards the front edge, and is configured so that when the winding shaft  12  rotates in the unwinding direction of the screen  11  along with that rotation, and the nut  43  screws toward the stopper  44  along the screw shaft  42  that is in a fixed state. 
   The corner linking material  8  is formed so as to be vertically symmetrical with the aforementioned upper corner linking material  6 , and therefore, similar to the corner linking material  6 , is equipped with a linking material main unit  46  and an end cover  47 . 
   Further, the clutch mechanism  50  prevents the rotation of the screw shaft  42  by the rotational force and so forth of the of the winding shaft  12 , but the rotation of the operating ring  49  that borders on the opening portion of the end cover  47  of the corner linking material  8  can be propagated to the screw shaft  42 . 
   Therefore, by operating the aforementioned operating ring  49 , the screw shaft  42  can be rotated in either the forward or backward direction, and the rotation of this screw shaft  42  rotates integrally with the winding shaft  12 , but the nut  43  that is capable of moving in the axial direction of the winding shaft  12  screws in the direction of either upper or lower along the screw shaft  42 , and thus the distance between the nut  43  and the stopper  44  changes. Therefore, when the screen  11  is unwound by the rotation of the winding shaft  12 , the amount of rotation of the winding shaft until the nut  43  reaches the stopper  44  changes, the thus the unwinding limit of the screen  11  can be adjusted. 
   The configuration of the clutch mechanism  50  is essentially the same to that of the aforementioned clutch mechanism  30 , and the only point that differs from the aforementioned clutch mechanism  30  is that the aforementioned clutch mechanism  30  has a pair of protruding portions  33  and a cylinder unit  32  provided on the base edge of the linking shaft  26 , whereas this clutch mechanism  50  has a cylinder unit and a pair of protruding portions that correspond to this cylinder unit  32  and protruding portion  33  on the base edge of the support shaft  41  that is inserted into the winding shaft  12 . 
   Therefore, the clutch cylinder is provided as one unit on the inner face of the end cover  47  of the aforementioned corner linking material  8 , and a clutch spring  52  is wound thereupon that is pressed in the direction of reduction in diameter, and pressed against the surface of the clutch cylinder, the both edges of the bent portion are positioned on the both sides of the engaging protruding portion provided in a protruding manner from the inner face of the operating ring  49  that borders on the opening unit of the end cover  47 , and these functions do not differ from the case of the previously described clutch mechanism  30 , and therefore the detailed description thereof will be omitted. 
   Now, with the aforementioned clutch mechanism  50 , when the operating ring  49  is rotated in either direction, the rotation of the operating ring  49  is propagated to the screw shaft  42  and the nut  43  moves, but it goes without saying that even if the rotational force acts on the screw shaft  42  by the rotations force of the winding shaft  12  and so forth, the screw shaft  42  does not rotate because of the existence of this clutch mechanism  50 , and the rotations force is not propagated to the operating ring  49 . 
   Further, the aforementioned stopper mechanism  40  has the screw shaft  42  provided on the corner linking material  8 , whereupon the nut  43  is screwed, inserted into the winding shaft  12 , but the aforementioned nut  43  is engaged with the screw shaft  42  by spline engaging and so forth, and therefore, the winding shaft  12  and the corner linking material  8  are linked so as to be detachable. Specifically, the edge portion of the winding shaft  12  is supported on the support shaft  41  of the screw shaft  42  so as to be capable of rotating, and in this instance, a washer  53  is placed between the shaft edge of the winding shaft  12  and the support face receiving the shaft edge of the winding shaft  12  of the corner linking material  8 . 
   Regarding the aforementioned screen device, the guide grooves  2   c  and  3   c  that guide the upper and lower edges of the screen  11  are provided on the upper and lower frame material  2  and  3 , and prevent the upper and lower edges of the screen  11  from derailing from those guide grooves  2   c  and  3   c  due to an external force such as the wind, but in the case that it is derailed for some reason, if the screen  11  is wound onto the winding shaft  12  in this state, one portion of the screen  11  is over the groove wall of the guide groove, so winding may be performed with wrinkles from that portion, and in that case, the opening and closing of the screen  11  becomes unsmooth due to the wrinkles. 
   In order to avoid this problem, an extension portion  55  of the aforementioned guide grooves  2   c  and  3   c  are provided in a position close to the winding shaft  12 , on the corner linking materials  6  and  8  that are positioned on the upper and lower edges of the side frame  4 , and a guide groove  57  is provided within the area of the winding width of the screen  11  onto the winding shaft  12 , that returns the screen  11  that had been derailed from the guide groove within the extension portion  55  when rewinding onto the winding shaft  12 , onto both side groove walls  56  that make up the extension portions. 
   The guide groove  57  is provided in a diagonal direction within the guide groove extension portion  55  from the outside of the guide grooves  2   c  and  3   c , from the direction farther from the side frame  4  towards the direction closer to the side frame  4 , thus, even if one or both of the upper and lower edges of the screen  11  are derailed from the guide grooves  2   c  and  3   c , upon the derailed portion of the screen edge being wound onto the winding shaft  12 , the winding is performed smoothly because the edge portion of the screen  11  over the entire winding width of the screen  11  onto the winding shaft  12  passes through the guiding groove  57 , and wrinkling does not occur with the screen  11 . 
   Further, when the movable rail  13  moves closer to the side frame  4 , the portion of the screen  11  that is derailed from the guide groove must jump the guide grooves  2   c  and  3   c  or the guide walls of the extension portions  55  thereof, but because the one edge of the screen  11  is fixed onto the movable rail  13  across the entire width, and the other edge of the screen is being properly wound onto the winding shaft  12 , force is generated to return the screen  11  over the groove wall  56  into the guide groove extension portion  55 , and by moving the movable rail  13  back and forth two or three times at a position close to the side frame  4 , the screen  11  can easily be returned. 
   As described above, the aforementioned screen device has common upper and lower frame material  2  and  3 , and also forms the upper and lower corner linking materials  6  and  8  to be vertically symmetrical to  7  and  9 , with the exception of the winding mechanism  20  and the stopper mechanism  40 . 
   Further, both edges of the winding shaft  12  are supported on the supporting face of the corner linking materials  6  and  8  via the washers  36  and  53 , so as to be capable of rotating, and can be used smoothly even if the screen  1  is turned upside down. 
   By making such a retractable screen device capable of turning upside down, the hanging side is changed between left and right sides in the case illustrated herein of the single opening screen device, and a user-friendly screen device can be installed. 
     FIG. 5  illustrates the second embodiment of the present invention, and this embodiment illustrates the case in which the screen device opens on both sides. 
   In the case of this second embodiment, compared to the above-described first embodiment, left and right side frames  64  and  65  that comprise a screen frame  61  have the same configuration as the side frame  4  of the above embodiment, which are configured by winding boxes that have winding shafts  72   a  and  72   b  for screens  71   a  and  71   b , and therefore movable rails  73   a  and  73   b  that are fixed on the front edges of the left and right screens  71   a  and  71   b  are provided with respective engaging latches  78   a  and  78   b . In other words, by using the same configuration for the side frame  5  as the side frame  4  of the screen device in the aforementioned first embodiment, the screen device can be used as the double opening type of the second embodiment, simply by taking into consideration using mutually engaging latches for the movable rails. 
   Now, the construction of the second embodiment other than that described above does not differ from the case of the first embodiment, and so the description thereof will be omitted. 
   According to the retractable screen device of the present invention described in detail above, with a screen device wherein a screen is wound onto a winding shaft that uses a spring as a drive source, and automatically rewinds this screen, in the case of installing this onto a building opening portion, the upper and lower frame material and the left and right side frames of the screen frame are cut to the necessary length corresponding to the dimensions of the aforementioned opening portion, and can be adjusted easily to the dimensions that fit with the size of that opening, and when such dimension adjustment is performed, adjusting the winding force of the aforementioned winding mechanism and setting the screen pullout limit can also be easily performed. 
   Further, even if the upper and lower edges of the screen derail from the guide groove, rewinding the screen can be performed smoothly.

Summary:
A retractable screen device including a screen frame formed by upper and lower frame members and right and left side frames, each having a fixed cross section along its entire axis, and corner linking members linking the ends of the frame members and side frames together at four corners of the screen frame. One of a pair of corner linking members situated at the ends of the side frame carrying a screen winding shaft includes a winding mechanism that is movable into and out of the winding shaft to cause the winding shaft to wind a screen thereon with aid of an adjustable spring force, while the other corner linking member includes a stopper mechanism that is movable into and out of the winding shaft to define an adjustable limit to a degree of unwinding of the screen from the winding shaft.