Screen device

Abstract

To provide a screen device which prevents adjacent sections of a wire that is wound on a winding drum from being entangled with each other.SOLUTION: A screen device includes a screen 3 for opening / closing a building opening, a take-up roller 4 for taking up the screen, a movable bar for operating the opening / closing of the screen, a take-up drum 40 mounted on a drum shaft 29 disposed coaxially with the take-up roller 4, a wire 30 connecting the take-up drum 40 and the movable bar, and a coil spring 34 disposed inside the take-up roller 4, having one end and the other end connected to the take-up roller 4 and the drum shaft 29, and transmitting a torsion urging force to the take-up roller 4 and the drum shaft 29 as a rotational force in the direction in which the screen 3 and the wire 30 are taken up, wherein the take-up drum 40 has a truncated cone shape and has a large diameter portion 41a that is a winding start end of the wire 30 and a small diameter portion 41b that is a winding end of the wire, and a spiral fitting groove 45 into which the wound wire is fitted is formed on the outer periphery of the take-up drum 40 so as to connect the winding start end and the winding end.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a screen device that is attached to a building opening and used for purposes such as shading, privacy, or insect prevention.

Background Art

[0002] Screen devices that are attached to building openings and used for purposes such as shading, privacy, or insect prevention have been known in various forms. Patent Document 1 discloses, as an example of such a screen device, a curtain opening / closing device. This curtain opening / closing device opens and closes a building opening by raising and lowering a curtain, and has an operating force adjustment mechanism for adjusting the operating force when opening and closing the curtain. The operating force adjustment mechanism includes a support shaft (drum shaft) arranged in parallel with a winding shaft for winding the curtain, a winding reel (winding drum) attached to the support shaft, a suspension cord (wire) whose base end is wound around the winding reel and whose tip end is connected to the upper end of the curtain, and a coil spring whose both ends are connected to the winding shaft and the support shaft and transmits the biasing force accumulated by twisting as a rotational force in the direction of winding the curtain and the wire around the winding shaft and the support shaft. By absorbing the rotational difference between the winding shaft and the winding reel in the coil spring, the operating force when opening and closing the curtain is adjusted. However, in the conventional curtain opening / closing device, since the winding drum has a structure in which the wire is wound multiple times around the circumferential surface of a cylindrical surface partitioned by a pair of flanges, the wound wires are likely to get entangled and lock with each other, and it is difficult to smoothly pay out the wire from the winding drum, which may hinder the opening and closing operation of the curtain.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] The technical problem of the present invention is to provide a screen device having an operating force adjustment mechanism for adjusting the operating force when opening and closing a curtain, which prevents the wires wound on the winding drum from becoming entangled, thereby enabling smooth opening and closing of the screen. [Means for solving the problem]

[0005] To solve the aforementioned problems, the present invention provides a screen device comprising: a screen for opening and closing a building opening; a winding box disposed at one end of the building opening; a winding roller rotatably and detachably supported inside the winding box for winding up and unwinding the screen when the building opening is opened and closed by the screen; a movable slat for opening and closing operations attached to the front of the screen; and an operating force adjustment mechanism for adjusting the operating force when opening and closing the curtain with the movable slat, wherein the operating force adjustment mechanism comprises: a drum shaft disposed coaxially with the winding roller so as to be rotatable relative to the winding roller; a winding drum attached to one end of the drum shaft; and a slat whose base end is connected to the winding drum and which is routed around inside the building opening. A screen device comprising a wire whose end is connected to the movable batten from the other end of the building opening, and a coil spring disposed inside the winding roller, with one end and the other end connected to the winding roller and drum shaft, which is twisted by the relative rotation of the winding roller and drum shaft to accumulate biasing force, and transmits the accumulated biasing force to the winding roller and drum shaft as rotational force in the direction of winding the screen and wire, wherein the winding drum is frustoconical in shape and has a large diameter portion which is the starting end when winding the wire and a small diameter portion which is the ending end when winding the wire, and the outer circumference of the winding drum is formed such that a fitting groove into which the wound wire fits is spirally connected to the large diameter portion and the small diameter portion.

[0006] In the present invention, it is preferable that the fitting groove is arc-shaped, the depth of the fitting groove is greater than the curvature deformation of the arc, and the width of the partition wall separating adjacent fitting grooves is smaller than the groove width of the fitting groove.

[0007] Furthermore, in the present invention, it is preferable that the diameter of the portion that forms the starting end of winding in the large-diameter section of the winding drum is equal to the winding diameter of the screen when the winding roller has wound up the screen and opened it completely, and that the diameter of the portion that forms the ending end of winding in the small-diameter section of the winding drum is equal to the diameter of the winding roller.

[0008] Furthermore, in the present invention, the large-diameter portion of the winding drum may have a plurality of wire locking holes formed at different positions on the fitting groove for fixing the base end of the wire to serve as the winding start end, and the position of the winding start end may be changed by selectively using the plurality of wire locking holes.

[0009] Furthermore, in the present invention, the wire consists of a single-wire section having one wire and a double-wire section having two wires connected to the tip of the single-wire section, wherein the single-wire section is the part that is wound onto the winding drum or unwound from the winding drum when the screen is opened and closed, and preferably the tip of one of the two wires in the double-wire section is connected to one end of the movable rig in the longitudinal direction, and the tip of the other wire is connected to the other end of the movable rig in the longitudinal direction.

[0010] Preferably in the present invention, bearings are attached to one end and the other end of the winding roller in the axial direction, and brackets provided at both ends in the longitudinal direction of the winding box are provided with bearing receivers and bearing retainers that are detachably attached to the bearing receivers, and the winding roller is rotatably and detachably supported inside the winding box by sandwiching the bearing between the bearing receiver and the bearing retainer.

[0011] Furthermore, in the present invention, locking members may be attached to both ends of the screen in the width direction, which are slidably locked to a screen frame that guides both ends. [Effects of the Invention]

[0012] The screen device of the present invention has a spiral fitting groove on the outer surface of the winding drum into which the wound wire fits. This allows the wire to be wound neatly in a spiral without overlapping, and therefore the wires do not become entangled with each other, which would interfere with the opening and closing operation of the screen. [Brief explanation of the drawing]

[0013] [Figure 1] This is a front view showing one embodiment of the screen device according to the present invention. [Figure 2] This is a close-up view of the main part of the winding box in Figure 1. [Figure 3] Figure 2 is an exploded view. [Figure 4] This is a perspective view of the bottom of the winding box. [Figure 5] This is an enlarged cross-sectional view of the main part shown in Figure 1. [Figure 6] This is a plan view of the bearing. [Figure 7] This is a front view of the winding drum. [Figure 8] This is a bottom view of the winding drum. [Figure 9] This is a longitudinal cross-section of the winding drum. [Figure 10] This is an enlarged view of the main part of Figure 9. [Figure 11] This is a schematic plan view of the screen device when the screen is fully open, showing the winding roller and winding drum separated, and the number of turns of the coil spring reduced. [Figure 12] This is a schematic diagram of the screen device when the screen is half-open. [Figure 13] This is a schematic diagram of the screen device when the screen is fully closed.

Best Mode for Carrying Out the Invention

[0014] Figures 1 - 5 show an embodiment of a screen device according to the present invention. This screen device 1 is a side-opening screen device that opens and closes a building opening by horizontally moving a screen 3. As shown in Figure 1, a screen winding unit 2 configured to wind the screen 3 with a winding roller 4 is detachably attached to a rectangular screen frame 5 attached to the building opening.

[0015] In the present invention, winding the screen 3 with the winding roller 4 to open the building opening is referred to as "opening the screen 3", and feeding out the screen 3 from the winding roller 4 to close the building opening is referred to as "closing the screen 3" or "shutting the screen 3". Therefore, "opening and closing the screen 3" means "opening and closing the building opening with the screen 3".

[0016] The screen frame 5 has a winding box 6 vertically arranged at one end in the left-right direction of the building opening, an upper horizontal frame bar 7 and a lower horizontal frame bar 8 horizontally extending along the upper side and the lower side of the building opening from the upper end and the lower end of the winding box 第6, respectively, and a vertical frame bar 9 vertically arranged at the other end in the left-right direction of the building opening.

[0017] The screen winding unit 2 has the screen 3 and the cylindrical winding roller 4 for winding and feeding out the screen 3. At the upper end of the winding roller 4, a cylindrical first roller shaft 4a having a smaller diameter than the winding roller 4 is coaxially attached to the winding roller 4. At the lower end of the winding roller 4, a cylindrical second roller shaft 4b having a smaller diameter than the winding roller 4 is coaxially attached to the winding roller 4. Bearings 13 as rolling bearings are respectively attached to the first roller shaft 4a and the second roller shaft 4b, and the winding roller 4 is supported inside the winding box 6 so as to be rotatable and removable through the bearing 13.

[0018] As shown in Figure 6, the bearing 13 consists of a concentrically arranged annular inner ring 13a and outer ring 13b, and a plurality of rolling elements 13c, each consisting of balls or rollers, interposed between the inner ring 13a and the outer ring 13b. The bearings 13 are attached to both the upper and lower ends of the winding roller 4 by press-fitting the ends of the first roller shaft 4a and the second roller shaft 4b of the winding roller 4 into the interior of the inner ring 13a.

[0019] The bearing 13 attached to the first roller shaft 4a is supported by a first bracket 11 provided at one end (upper end) in the longitudinal direction (up and down direction) of the winding box 6 via a bearing holder 24 and a bearing retainer 25. The bearing 13 attached to the second roller shaft 4b is supported by a second bracket 12 provided at the other end (lower end) in the longitudinal direction (up and down direction) of the winding box 6 via a bearing holder 24 and a bearing retainer 25 similar to those attached to the first bracket 11.

[0020] As is clear from Figures 3 and 4, the bearing holder 24 is made of a semicircular member and has a semicircular contact surface 24a that the outer circumferential surface of the outer ring 13b of the bearing 13 abuts against. It is fixed to the mutually opposing inner surfaces of the first bracket 11 and the second bracket 12 by mounting screws 27, and screw holes 24c are formed in the mounting surfaces 24b at both ends of the bearing holder 24 for screwing in mounting screws 26 for attaching the bearing retainer 25.

[0021] On the other hand, the bearing retainer 25 has a semicircular main body portion 25a having a semicircular contact surface 25b that abuts against the outer circumferential surface of the outer ring 13b of the bearing 13, and mounting portions 25c connected to both ends of the main body portion 25a. Screw insertion holes 25d are formed in the mounting portions 25c, and the bearing retainer 25 is detachably attached to the bearing receiver 24 by screwing mounting screws 26 inserted through the screw insertion holes 25d into screw holes 24c formed in the mounting surfaces 24b at both ends of the bearing receiver 24, while the outer ring 13b of the bearing 13 is sandwiched between the bearing retainer 25 and the bearing receiver 24. By removing the mounting screws 26 and separating the bearing retainer 25 from the bearing receiver 24, the winding roller 4, i.e., the screen winding unit 2, can be removed from the winding box 6 together with the bearing 13, as shown in Figure 3.

[0022] Furthermore, since the upper end of the first roller shaft 4a protrudes above the first bracket 11, the first bracket 11 has a notch 11a formed therein for inserting and removing the upper end of the first roller shaft 4a when attaching and detaching the winding roller 4 to the winding box 6.

[0023] Returning to Figure 1, a movable bar 14 for opening and closing is connected to the tip of the screen 3. The upper and lower ends of this movable bar 14 are fitted into guide grooves formed in the upper horizontal frame rod 7 and the lower horizontal frame rod 8 of the screen frame 5, and are guided by the upper horizontal frame rod 7 and the lower horizontal frame rod 8 when the screen 3 is opened or closed.

[0024] Furthermore, the upper and lower ends of the screen 3, which are both ends in the width direction, are fitted into slits of inner rails (not shown) housed within the upper horizontal frame rod 7 and lower horizontal frame rod 8, respectively, and move along these slits when opening and closing. Locking members 19 are attached to the upper and lower ends of the screen 3, and these locking members 19 are slidably locked to the inner edges of the slits. This not only smoothly guides the screen 3 along the upper horizontal frame rod 7 and lower horizontal frame rod 8 when opening and closing, but also prevents the upper and lower ends from detaching from the upper and lower horizontal frame rods 7 and lower horizontal frame rod 8 due to bending caused by wind pressure or other forces.

[0025] As the locking member 19, for example, one of the teeth of a pair of interlocking teeth of a slide fastener can be used, but any object other than a tooth that can slide along the inner edge of the slit while being locked to the inner edge of the slit is also acceptable. The same locking member 19 is used to connect the screen 3 and the movable rib 14, in which the tip of the screen 3 is inserted into a slit formed vertically in the movable rib 14, and the locking member 19 attached to the tip is locked to the inner edge of the slit, thereby connecting the screen 3 and the movable rib 14.

[0026] The winding box 6 has a cover attached to its front surface by hinges, screws, or other mounting members so as to be able to open and close or be separated. Normally, the front surface of the winding box 6 is covered by this cover, and the cover is configured to be opened during maintenance or when attaching or detaching the screen winding unit 2, but the cover is not shown in the illustration.

[0027] As shown in Figure 5, a round drum shaft 29 is housed inside the first roller shaft 4a, which is provided at the upper end of the winding roller 4, so as to be able to rotate coaxially with the winding roller 4.

[0028] The upper end of the drum shaft 29 protrudes upward from the upper end of the first roller shaft 4a and extends into the interior of the upper horizontal frame rod 7. A truncated cone-shaped winding drum 40 is attached to the upper end of the drum shaft 29, and the base end of a wire 30 connecting the winding drum 40 and the movable crossbar 14 is connected to the winding drum 40. The wire 30 is configured to be wound onto the winding drum 40 or unwound from the winding drum 40 when the screen 3 is opened or closed. More specifically, when the screen 3 is unwound from the winding roller 4 to close the building opening, the wire 30 is wound onto the winding drum 40, and when the screen 3 is wound onto the winding roller 4 to open the building opening, the wire 30 is unwound from the winding drum 40.

[0029] As shown in detail in Figures 7-10, the winding drum 40 has a frustoconical hollow drum body 41 having a large diameter portion 41a and a small diameter portion 41b, a cylindrical mounting portion 42 extending concentrically inside the drum body 41, and a plurality of reinforcing ribs 43 radially provided between the outer surface of the mounting portion 42 and the inner surface of the drum body 41. The winding drum 40 is coaxially mounted on the drum shaft 29 with the large diameter portion 41a facing downwards and the small diameter portion 41b facing upwards, by inserting the upper end of the drum shaft 29 into the mounting portion 42 and fixing it with a locking fitting 44 such as a screw or pin.

[0030] The large-diameter portion 41a of the winding drum 40 is the starting end when winding the wire 30, and the small-diameter portion 41b is the ending end when winding the wire 30. A fitting groove 45 into which the wound-up wire 30 fits is formed on the outer circumferential surface of the winding drum 40, connecting the large-diameter portion 41a and the small-diameter portion 41b in a spiral shape, and the wire 30 is wound spirally along this fitting groove 45. A flange portion 41c is formed on the small-diameter portion 41b to prevent the wire 30 from coming off the winding drum 40, and the position where the wire 30 abuts against or approaches this flange portion 41c is set to be the ending end of the winding of the wire 30.

[0031] As shown in Figure 10, the groove shape of the fitting groove 45 is arc-shaped, the depth of the fitting groove 45, i.e., the depth h from the conical surface s which is the outer surface of the winding drum 40 is greater than the radius of curvature r of the arc, and the width w1 of the partition wall 47 separating the vertically adjacent fitting grooves 45, 45 is smaller than the groove width w2 of the fitting groove 45.

[0032] Here, as schematically shown in Figure 11, the rotation direction a of the winding roller 4 when winding the screen 3 and the rotation direction b of the winding drum 40 when winding the wire 30 are in opposite directions. In this embodiment, the rotation direction a of the winding roller 4 when winding the screen 3 is set to clockwise, and the rotation direction b of the winding drum 40 when winding the wire 30 is set to counterclockwise. However, the opposite may also be true.

[0033] Furthermore, the length of the screen 3 and the length of the wire 30 are related such that when the screen 3 is fully open (see Figure 11), that is, when the screen 3 is completely wound onto the winding roller 4, the single-strand portion 30A of the wire 30 (described later) is completely unwound from the winding drum 40, and when the screen 3 is fully closed (see Figure 13), that is, when the screen 3 is completely unwound from the winding roller 4, the single-strand portion 30A of the wire 30 is completely wound onto the winding drum 40.

[0034] Furthermore, the diameter d1 of the winding drum 40 at the winding start end is approximately equal to the winding diameter D1 of the screen 3 when the winding roller 4 has wound up the screen 3 and opened it completely, as shown in Figure 11, and the diameter d2 of the winding end of the winding drum 40, i.e., the small diameter portion 41b, is set to be approximately equal to the outer diameter D2 of the winding roller 4.

[0035] Furthermore, as shown in Figure 7, the large-diameter portion 41a of the winding drum 40 has multiple wire locking holes 46 at different positions on the fitting groove 45 for locking the base end of the wire 30 to form the starting end of the winding. By selectively using these multiple wire locking holes 46, the position of the starting end of the wire 30 can be changed. In the illustrated embodiment, the wire locking holes 46 are provided at a total of four locations: position P1 at the end of the fitting groove 45, position P2 three pitches further along the spiral of the fitting groove 45 from the end, position P3 three more pitches further, and position P4 three more pitches further. This allows the position of the starting end of the winding, i.e., the length of the wire 30 wound by the winding drum 40, to be changed in four stages to match the length of the screen when using screens of various lengths.

[0036] As shown in Figure 1, the wire 30 has a single-wire section 30A on the base end side of the branching section 31 and a double-wire section 30B on the tip side of the branching section 31. The single-wire section 30A consists of one wire 30a, and the double-wire section 30B branches into two wires 30b and 30c. The single-wire section 30A is the part that is wound onto the winding drum 40 or unwound from the winding drum 40 when the screen 3 is opened and closed. On the other hand, the two wires 30b and 30c in the double-wire section 30B are routed around a plurality of guide pulleys 33a, 33b, and 33c provided within the screen frame 5. The tip of one wire 30b is connected from the guide pulley 33b at the upper end of the vertical frame rod 9 to the upper end of the movable rib 14, and the tip of the other wire 30c is connected from the guide pulley 33c at the lower end of the vertical frame rod 9 to the lower end of the movable rib 14.

[0037] Returning to Figure 5, the lower end of the drum shaft 29 protrudes from the lower end of the first roller shaft 4a into the winding roller 4, and a coil spring 34 is arranged inside the winding roller 4 so as to surround the drum shaft 29. One end (lower end) 34a of the coil spring 34 is locked to the drum shaft 29, and the other end (upper end) 34b of the coil spring 34 is locked to the first roller shaft 4a.

[0038] The coil spring 34 is pre-torn by increasing its number of turns, and this initial torsion constantly acts on the winding roller 4 and the drum shaft 29, causing the coil spring 34 to unwind. The direction of this biasing force is opposite for the winding roller 4 and the drum shaft 29. As shown in Figure 11, for the winding roller 4, it is in the direction a, i.e., clockwise, which winds the screen 3, and for the drum shaft 29, it is in the direction b, i.e., counterclockwise, which winds the winding drum 40 and the wire 30. As a result, the screen 3 and the wire 30 are always under tension, preventing malfunctions due to loosening.

[0039] As a method for applying initial twist to the coil spring 34, before attaching the screen winding unit 2 to the winding box 6, the winding roller 4 and the drum shaft 29 are rotated relative to each other to apply initial twist to the coil spring 34. In this state, the drum shaft 29 and the first roller shaft 4a are fixed together with a locking fitting 35 such as a snap pin so that they cannot rotate relative to each other. After attaching the screen winding unit 2 to the winding box 6 in this state, the locking fitting 35 is removed.

[0040] Next, the operation of the screen device 1 will be explained. Figures 11-13 are schematic diagrams showing the screen device 1 in a plan view with the coaxially mounted winding roller 4 and winding drum 40 separated from each other, and the number of turns of the coil spring 34 reduced. Figure 11 shows the screen 3 fully open, Figure 12 shows the screen 3 half-open, and Figure 13 shows the screen 3 fully closed.

[0041] In the screen device 1, when the screen 3 is fully open as shown in Figure 11, the coil spring 34, which has an initial twist applied to it, acts as a rotational force on the winding roller 4 in the direction of arrow a, and a rotational force acts on the drum shaft 29, i.e., the winding drum 40, in the direction of arrow b. From this state, when the movable sill 14 is moved to the left in the figure (direction of arrow m) to unwind the screen 3 from the winding roller 4, the winding roller 4 rotates in the direction of arrow b, causing the coil spring 34 to twist, and the biasing force causes the drum shaft 29 and the winding drum 40 to rotate in the direction of arrow b. As a result, as shown in Figures 12 and 13, the winding drum 40 winds up a wire 30 of a length corresponding to the amount the movable sill 14 moves (the amount the screen 3 is unwound) in a spiral manner along the fitting groove 45 from the large diameter end 30a to the small diameter end 30b of the winding drum 40.

[0042] At this time, the rotational difference between the winding roller 4 and the drum shaft 29 (winding drum 40) caused by the difference in diameter between the winding diameter of the screen 3 by the winding roller 4 and the winding diameter of the wire 30 by the winding drum 40 may slightly increase or decrease the number of twists (turns) of the coil spring 34. However, the winding diameter of the screen 3 by the winding roller 4 and the winding diameter of the wire 30 by the winding drum 40 are set to change proportionally, and are related in such a way that there is no large difference between the two regardless of the open or closed state of the screen 3. Therefore, the number of turns of the coil spring 34 does not increase or decrease significantly. For this reason, the operating force required to unwind the screen 3 from the fully open position in Figure 7 through the half-open position in Figure 12 to the fully closed position in Figure 13 is averaged out and does not change significantly. Furthermore, the screen 3 can also be stopped at the half-open position in Figure 12. Therefore, the drum shaft 29 and coil spring 34, along with the winding drum 40 and wire 30, constitute an operating force adjustment mechanism for opening and closing the screen 3 using the movable strut 14.

[0043] Thus, in the present invention, by providing a spiral fitting groove 45 on the outer circumferential surface of the frustoconical winding drum 40, the wire 30 can be wound neatly in a spiral along the fitting groove 45 without overlapping or entanglement, and when the screen 3 is opened and closed, the winding diameter of the wire 30 on the winding drum 40 can be changed to correspond to the change in the winding diameter of the screen 3 on the winding roller 4.

[0044] Next, when the movable rib 14 is moved to the right in the diagram (direction of arrow n) to move the screen 3 from the fully closed position in Figure 13, through the half-open position in Figure 12, to the fully open position in Figure 11, and the screen 3 is wound onto the winding roller 4, the wire 30 is pulled out from the winding drum 40, causing the winding drum 40 and drum shaft 29 to rotate in the direction of arrow a, and the coil spring 34 is twisted. Due to this biasing force, the winding roller 4 rotates in the direction of arrow a and winds up the screen 3. At this time, even if the number of twists of the coil spring 34 increases or decreases slightly due to the difference in rotation between the winding drum 40 and the winding roller 4, as mentioned above, the number of turns of the coil spring 34 does not increase or decrease significantly. Therefore, the operating force when opening the screen 3 is also averaged out and does not change significantly.

[0045] In the above embodiment, the winding drum 40 is mounted on the drum shaft 29 with the large-diameter portion 41a facing downwards and the small-diameter portion 41b facing upwards. However, it can also be mounted on the drum shaft 29 in the opposite position, with the large-diameter portion 41a facing upwards and the small-diameter portion 41b facing downwards. Furthermore, while the screen device 1 is a horizontally opening type screen device that opens and closes a building opening by moving the screen 3 horizontally, the present invention can also be applied to a vertically opening type screen device that opens and closes a building opening by raising and lowering the screen 3 vertically. In this case, the winding box 6 is disposed at the upper or lower end of the building opening, and the winding roller 4 is mounted inside the winding box 6 via a bearing 13 so as to be rotatable about a horizontal axis. [Explanation of Symbols]

[0046] 1 Screen device 3 screens 4. Winding roller 6-roll box 11 First bracket 12 Second bracket 13 Bearings 14 Movable rails 19 Locking member 24 Bearing mount 25 Bearing retainer 29 Drum shaft 30 wires 30A Single track section 30B Double track section 30a Single-wire section 30b One wire in the double-track section 30c Other wire in the double track section 34 Coil springs 40 reel drums 41a Large diameter section 41b Small diameter section 41c Flange section 45 Fitting groove 46 Wire locking holes d1 Diameter of the starting end of the winding drum d2 Diameter of the small diameter section (end of winding) of the winding drum D1 screen winding diameter D2 diameter of the winding roller h Depth of the fitting groove r: radius of curvature of the circular arc w1 Width of the partition wall w2 groove width

Claims

1. The screen includes a screen for opening and closing a building opening, a winding box disposed at one end of the building opening, a winding roller rotatably and detachably supported inside the winding box for winding up and unwinding the screen when the building opening is opened or closed by the screen, a movable bar attached to the tip of the screen for opening and closing, and an operating force adjustment mechanism for adjusting the operating force when the movable bar is used to open and close the curtain. the operating force adjustment mechanism is a screen device having a drum shaft arranged coaxially with the winding roller so as to be rotatable relative to the winding roller, a winding drum attached to one end of the drum shaft, a wire whose base end is connected to the winding drum and is wound around inside the building opening, and whose tip end is connected to the movable crosspiece from the other end of the building opening, and a coil spring arranged inside the winding roller and whose one and other ends are connected to the winding roller and the drum shaft, which is twisted by the relative rotation between the winding roller and the drum shaft to accumulate an urging force and imparts the accumulated urging force to the winding roller and the drum shaft as a rotational force in a direction to wind up the screen and wire, The winding drum is shaped like a truncated cone and has a large diameter portion that serves as the winding start end when winding the wire and a small diameter portion that serves as the winding end end when winding the wire, and a fitting groove into which the wound wire fits is formed on the outer periphery of the winding drum so as to connect the large diameter portion and the small diameter portion in a spiral. A screen device characterized by:

2. 2. The screen device according to claim 1, wherein the engagement groove is arc-shaped, the depth of the engagement groove is greater than the curvature deformation of the arc, and the width of the partition wall separating adjacent engagement grooves is smaller than the groove width of the engagement groove.

3. 3. The screen device according to claim 1, wherein the diameter of the portion of the large diameter portion of the winding drum that forms the winding start end is equal to the winding diameter of the screen when the winding roller has wound up the screen and fully opened, and the diameter of the portion of the small diameter portion of the winding drum that forms the winding end is equal to the diameter of the winding roller.

4. The screen device according to claim 1 or 2, characterized in that a plurality of wire locking holes for locking the base end of the wire to form a winding start end are formed at different positions on the engagement groove in the large diameter portion of the winding drum, and the position of the winding start end can be changed by selectively using the plurality of wire locking holes.

5. The screen device according to claim 1 or 2, characterized in that the wire consists of a single wire section having one wire and a double wire section branching into two wires, the single wire section being the part that is wound onto and unwound from the winding drum when the screen is opened and closed, and the tip of one of the two wires in the double wire section is connected to one end of the movable bar in the longitudinal direction, and the tip of the other wire is connected to the other end of the movable bar in the longitudinal direction.

6. 3. The screen device according to claim 1 or 2, wherein a bearing is attached to each of one and the other axial ends of the winding roller, and brackets provided at both longitudinal ends of the winding box are each provided with a bearing holder and a bearing retainer that is detachable from the bearing holder, and the winding roller is supported rotatably and detachably inside the winding box by sandwiching the bearing between the bearing holder and the bearing retainer.

7. 3. The screen device according to claim 1, wherein locking members are attached to both widthwise ends of the screen to slidably lock onto screen frames that guide the both widthwise ends.

Images