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 an opening in a building and used for purposes such as shading, privacy, or insect control. [Background technology]

[0002] BACKGROUND ART Screen devices that are attached to building openings and used for purposes such as shading, privacy, or insect control have been known in various forms. Patent Document 1 discloses a curtain opening and closing device as an example of such a screen device. This curtain opening and closing device opens and closes an opening in a building 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 comprises a support shaft (drum shaft) arranged parallel to the winding shaft for winding up the curtain, a winding reel (winding drum) attached to the support shaft, a suspension rope (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 support shaft and which transmits the biasing force accumulated by torsion to the winding shaft and support shaft as a rotational force in the direction of winding up the curtain and wire, and by having the coil spring absorb the rotational difference between the winding shaft and the winding reel, the operating force when opening or closing the curtain is adjusted. However, in the conventional curtain opening and closing device, the winding drum is structured so that the wire is wound in multiple layers around a cylindrical surface separated by a pair of flanges, and the wound wires tend to become tangled and interlock with each other, making it difficult to unwind the wire from the winding drum smoothly, which can sometimes interfere with the opening and closing operation of the curtain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-170477 Summary of the Invention [Problem to be solved by the invention]

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

[0005] In order to solve the above-mentioned problems, the screen device of the present invention comprises a screen for opening and closing an opening in a building, a winding box disposed at one end of the opening in a building, a winding roller rotatably and detachably supported inside the winding box and winding and unwinding the screen when the opening in a building is opened or closed by the screen, a movable bar for opening and closing operation attached to the tip of the screen, and an operating force adjustment mechanism for adjusting the operating force when opening and closing the curtain with the movable bar, the operating force adjustment mechanism comprising 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 winding drum whose base end is connected to the winding drum and which is hung inside the opening in a building, In a screen device having a wire whose end is connected to the movable crosspiece from the other end side of the building opening, and a coil spring disposed inside the winding roller and connected at one and the other ends to the winding roller and drum shaft, which is twisted by the relative rotation of the winding roller and the drum shaft to accumulate a biasing force and transmits the accumulated biasing force to the winding roller and drum shaft as a rotational force in the direction of winding the screen and wire, the winding drum is frustum-shaped and has a large diameter portion which becomes the winding start end when winding the wire, and a small diameter portion which becomes 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 spirally connect the large diameter portion and the small diameter portion.

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

[0007] Furthermore, in the present invention, it is preferable that the diameter of the portion of the large diameter section 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 that the diameter of the portion of the small diameter section of the winding drum that forms the winding end is equal to the diameter of the winding roller.

[0008] In addition, 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 engagement groove for fixing the base end of the wire to form 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, it is preferable that the wire comprises a single wire section having one wire and a double wire section having two wires connected to the tip of the single wire section, 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 that 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.

[0010] In the present invention, preferably, 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 provided with a bearing holder and a bearing retainer that is detachable from the bearing holder, and by clamping the bearing between the bearing holder and the bearing retainer, the winding roller is supported inside the winding box so that it can be rotated and detached freely.

[0011] In the present invention, locking members may be attached to both widthwise ends of the screen to slidably lock the both widthwise ends to screen frames that guide the both widthwise 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, so that the wire can be wound up in an orderly spiral shape without overlapping, and therefore the wires do not become tangled and interfere with the opening and closing operation of the screen. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a front view showing an embodiment of a screen unit according to the present invention. [Figure 2] FIG. 2 is an enlarged view of a main part of the winding box portion in FIG. [Figure 3] FIG. 3 is an exploded view of FIG. 2. [Figure 4] FIG. 2 is a perspective view of the bottom of the winding box. [Figure 5] FIG. 2 is an enlarged cross-sectional view of a main part of FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 2 is a vertical cross-sectional view of the winding drum. [Figure 10] FIG. 10 is an enlarged view of a main part of FIG. 9. [Figure 11] FIG. 10 is a schematic plan view of the screen device when the screen is fully opened, in which the winding roller and the winding drum are separated and the number of turns of the coil spring is reduced. [Figure 12] FIG. 2 is a schematic diagram of the screen device when the screen is half-opened. [Figure 13] FIG. 2 is a schematic diagram of the screen device when the screen is fully closed. DETAILED DESCRIPTION OF THE INVENTION

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

[0015] In the present invention, winding up the screen 3 on the winding roller 4 to open the building opening is referred to as "opening the screen 3," and unwinding the screen 3 from the winding roller 4 to close the building opening is referred to as "closing the screen 3" or "closing 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 arranged vertically at one end of the building opening in the left-right direction, an upper horizontal frame rod 7 and a lower horizontal frame rod 8 extending horizontally from the upper and lower ends of the winding box 6 along the upper and lower edges of the building opening, respectively, and a vertical frame rod 9 arranged vertically at the other end of the building opening in the left-right direction.

[0017] The screen winding unit 2 has the screen 3 and the cylindrical winding roller 4 that winds and unwinds the screen 3. A cylindrical first roller shaft 4a with a smaller diameter than the winding roller 4 is attached coaxially to the upper end of the winding roller 4, and a cylindrical second roller shaft 4b with a smaller diameter than the winding roller 4 is attached coaxially to the lower end of the winding roller 4. Bearings 13 serving as rolling bearings are attached to each of the first roller shaft 4a and second roller shaft 4b, and the winding roller 4 is supported within the winding box 6 via the bearings 13 so as to be rotatable and removable.

[0018] As shown in FIG. 6, the bearing 13 comprises concentrically arranged annular inner and outer rings 13a and 13b, and a plurality of rolling elements 13c made of balls or rollers interposed between the inner and outer rings 13a and 13b. The bearings 13 are attached to the upper and lower ends of the take-up roller 4 by press-fitting the ends of the first roller shaft 4a and the second roller shaft 4b of the take-up roller 4 into 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) of the longitudinal direction (vertical direction) of the winding box 6 via a bearing support 24 and a bearing presser 25, and the bearing 13 attached to the second roller shaft 4b is supported by a second bracket 12 provided at the other end (lower end) of the longitudinal direction (vertical direction) of the winding box 6 via a bearing support 24 and a bearing presser 25 similar to the bearing support 24 and bearing presser 25 attached to the first bracket 11.

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

[0021] On the other hand, the bearing holder 25 has a semicircular main body 25a having a semicircular abutment surface 25b against which the outer peripheral surface of the outer ring 13b of the bearing 13 abuts, and mounting portions 25c connected to both ends of the main body 25a, with screw insertion holes 25d formed in the mounting portions 25c, and with the outer ring 13b of the bearing 13 sandwiched between the bearing holder 25 and the bearing receiver 24, mounting screws 26 inserted into the screw insertion holes 25d are screwed into screw holes 24c formed in the mounting surfaces 24b at both ends of the bearing receiver 24, thereby detachably attaching the bearing holder 25 to the bearing receiver 24. By removing the mounting screws 26 and separating the bearing holder 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 FIG.

[0022] Since the upper end of the first roller shaft 4a protrudes upward from the first bracket 11, the first bracket 11 is formed with a notch 11a for inserting and removing the upper end of the first roller shaft 4a when attaching and detaching the winding roller 4 to and from the winding box 6.

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

[0024] The upper and lower ends of the screen 3 in the width direction are fitted into slits of inner rails (not shown) housed in the upper horizontal frame rod 7 and the lower horizontal frame rod 8, respectively, and move along the slits when opening and closing. vinegarLocking members 19 are attached to the upper and lower ends of the screen 3, and these locking members 19 are slidably engaged with the inner edges of the slits, so that the screen 3 is not only smoothly guided along the upper horizontal frame rod 7 and the lower horizontal frame rod 8 when opening and closing, but also prevents the upper and lower ends from coming off the upper horizontal frame rod 7 and the lower horizontal frame rod 8 due to bending caused by wind pressure, etc.

[0025] The locking member 19 can be, for example, one of a pair of interlocking teeth of a slide fastener, but anything other than a tooth can be used as long as it can slide along the inner edge of the slit while being locked onto the inner edge of the slit. A similar locking member 19 is also used to connect the screen 3 and the movable crosspiece 14, and the tip of the screen 3 is inserted into a slit formed in the movable crosspiece 14 in the vertical direction, and the locking member 19 attached to the tip locks onto the inner edge of the slit, thereby connecting the screen 3 and the movable crosspiece 14.

[0026] The winding box 6 has a cover attached to its front surface by mounting members such as hinges or screws so that it can be opened and closed or 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 this cover is not shown in the illustration.

[0027] As shown in Figure 5, a round rod-shaped drum shaft 29 is housed inside the first roller shaft 4a provided at the upper end of the winding roller 4 so that it can rotate freely 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, and a truncated cone-shaped winding drum 40 is attached to the upper end of the drum shaft 29, and a base end of a wire 30 connecting the winding drum 40 and the movable crosspiece 14 is connected to the winding drum 40, so that the wire 30 is wound onto and 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 around 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 to 10, the take-up drum 40 has a hollow truncated conical 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 provided radially between the outer surface of the mounting portion 42 and the inner surface of the drum body 41. The upper end of the drum shaft 29 is inserted into the mounting portion 42 and fixed with locking fittings 44 such as screws or pins, so that the take-up drum 40 is coaxially attached to the drum shaft 29 with the large diameter portion 41a facing downward and the small diameter portion 41b facing upward.

[0030] The large diameter portion 41a of the winding drum 40 is the portion that becomes the winding start end when winding the wire 30, and the small diameter portion 41b is the portion that becomes the winding end end when winding the wire 30. A fitting groove 45 into which the wound wire 30 fits is formed on the outer circumferential surface of the winding drum 40 so as to spirally connect the large diameter portion 41a and the small diameter portion 41b, and the wire 30 is configured to be 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 or comes close to this flange portion 41c is set to be the winding end end of the wire 30.

[0031] The groove shape of the fitting groove 45 is an arc shape as shown in Figure 10, and the depth of the fitting groove 45, i.e., the depth h from the conical surface s which is the outer peripheral surface of the winding drum 40, is larger than the radius of curvature r of the arc, and the width w1 of the partition 47 separating the adjacent fitting grooves 45, 45 above and below is smaller than the groove width w2 of the fitting groove 45.

[0032] 11, the rotation direction a when the winding roller 4 winds up the screen 3 and the rotation direction b when the winding drum 40 winds up the wire 30 are opposite to each other, and in this embodiment, the rotation direction a when the winding roller 4 winds up the screen 3 is set to be clockwise, and the rotation direction b when the winding drum 40 winds up the wire 30 is set to be counterclockwise. However, the opposite may also be possible.

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

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

[0035] 7, the large-diameter portion 41a of the winding drum 40 is provided with a plurality of wire locking holes 46 at different positions on the fitting groove 45 for locking the base end of the wire 30 to form a winding start end, and the position of the winding start end of the wire 30 can be changed by selectively using the plurality of wire locking holes 46. In the illustrated embodiment, the wire locking holes 46 are provided at a total of four positions: position P1 at the end of the fitting groove 45, position P2 three pitches from the end along the spiral of the fitting groove 45, position P3 another three pitches further, and position P4 another three pitches further. As a result, when screens of various lengths are used, the position of the winding start end, i.e., the winding length of the wire 30 by the winding drum 40, can be changed in four stages to suit the length.

[0036] As shown in Figure 1, the wire 30 has a single wire section 30A located at the base end side of the branch section 31 and a double wire section 30B located at the tip end side of the branch section 31, and the single wire section 30A consists of one wire 30a, and the double wire section 30B is branched into two wires 30b and 30c. The single wire section 30A is the part that is wound onto and unwound from the winding drum 40 when the screen 3 is opened or closed, while the two wires 30b, 30c in the double wire section 30B are passed around a plurality of guide pulleys 33a, 33b, 33c provided within the screen frame 5, and 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 crosspiece 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 crosspiece 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 inside of the winding roller 4, and a coil spring 34 is arranged inside the winding roller 4 so as to surround the drum shaft 29, with one end (lower end) 34a of the coil spring 34 engaged with the drum shaft 29 and the other end (upper end) 34b of the coil spring 34 engaged with the first roller shaft 4a.

[0038] An initial twist is applied to the coil spring 34 in advance by increasing the number of windings thereof, and due to this initial twist, an urging force (rotational force) in a direction in which the coil spring 34 tries to unwind is constantly acting on the take-up roller 4 and the drum shaft 29. The acting direction of the urging force is opposite to that of the take-up roller 4 and the drum shaft 29. As shown in Fig. 11, on the take-up roller 4, it is the direction a in which the screen 3 is wound up, i.e., clockwise, and on the drum shaft 29, it is the direction b in which the winding drum 40 winds up the wire 30, i.e., counterclockwise. As a result, the screen 3 and the wire 30 are constantly under tension, and malfunctions due to loosening do not occur.

[0039] A method of applying an initial twist to the coil spring 34 is to rotate the winding roller 4 and the drum shaft 29 relative to each other before attaching the screen winding unit 2 to the winding box 6, thereby applying an initial twist to the coil spring 34, and then fixing the drum shaft 29 and the first roller shaft 4a with a locking fitting 35 such as a snap pin so that they cannot rotate relative to each other, and then attaching the screen winding unit 2 to the winding box 6 in this state, and then removing the locking fitting 35.

[0040] Next, we will explain the operation of the screen unit 1. Figures 11 to 13 are schematic plan views of the screen unit 1 in which the coaxially mounted winding roller 4 and winding drum 40 are separated from each other and the number of turns of the coil spring 34 is reduced, with Figure 11 showing the screen 3 in a fully open state, Figure 12 showing the screen 3 in a half-open state, and Figure 13 showing the screen 3 in a fully closed state.

[0041] In the screen device 1, when the screen 3 is fully opened as shown in Fig. 11, a rotational force in the direction of arrow a acts on the winding roller 4 due to the coil spring 34 to which an initial twist has been applied, and a rotational force in the direction of arrow b acts on the drum shaft 29, i.e., the winding drum 40. When the movable crosspiece 14 is moved leftward in the figure (in the direction of arrow m) to unwind the screen 3 from the winding roller 4 from this state, the winding roller 4 rotates in the direction of arrow b, twisting the coil spring 34, and the drum shaft 29 and the winding drum 40 rotate in the direction of arrow b due to the biasing force of the coil spring 34. Therefore, as shown in Figs. 12 and 13, the winding drum 40 spirally winds up the wire 30 having a length corresponding to the amount of movement of the movable crosspiece 14 (the amount of unwinding of the screen 3) along the fitting groove 45 from the large diameter end 30a side to the small diameter end 30b side of the winding drum 40.

[0042] At this time, the number of twists (number of turns) of the coil spring 34 may increase or decrease slightly due to the difference in rotation 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 around the winding roller 4 and the winding diameter of the wire 30 around the winding drum 40; however, the winding diameter of the screen 3 around the winding roller 4 and the winding diameter of the wire 30 around the winding drum 40 are set to change proportionally and are related so that there is no large difference between them regardless of the open / closed state of the screen 3. Therefore, the number of turns of the coil spring 34 does not increase or decrease significantly. As a result, the operating force required to unwind the screen 3 from the fully open position in FIG. 7 via the half-open position in FIG. 12 to the fully closed position in FIG. 13 is averaged and does not change significantly, and the screen 3 can also be stopped at the half-open position in FIG. 12. Therefore, the drum shaft 29 and the coil spring 34, and the winding drum 40 and the wire 30 constitute an operation force adjusting mechanism when the screen 3 is opened or closed by the movable crosspiece 14.

[0043] As described above, in the present invention, by providing the spiral engagement groove 45 on the outer peripheral surface of the truncated cone-shaped winding drum 40, not only can the wire 30 be wound up spirally and orderly along the engagement groove 45 without overlapping or tangling, but also 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 when the screen 3 is opened or closed.

[0044] 13 to the fully open position in FIG. 11 via the half-open position in FIG. 12, and when the movable crosspiece 14 is moved to the right in the figure (in the direction of arrow n) to wind the screen 3 onto the winding roller 4, the wire 30 is pulled out from the winding drum 40, causing the winding drum 40 and the drum shaft 29 to rotate in the direction of arrow a and twisting the coil spring 34, and the resulting biasing force causes the winding roller 4 to rotate in the direction of arrow a and wind up the screen 3. At this time, even if the number of twists of the coil spring 34 may increase or decrease slightly depending on the rotational difference between the winding drum 40 and the winding roller 4, the number of turns of the coil spring 34 will not increase or decrease significantly as described above, and therefore the operating force required to open the screen 3 is averaged out and will not change significantly.

[0045] In the above embodiment, the winding drum 40 is attached to the drum shaft 29 with the large diameter portion 41a facing downward and the small diameter portion 41b facing upward, but it can also be attached to the drum shaft 29 with the large diameter portion 41a facing upward and the small diameter portion 41b facing downward. Furthermore, although the screen device 1 is a horizontal-opening type screen device that opens and closes an opening in a building by moving the screen 3 horizontally, the present invention can also be applied to a vertical-opening type screen device that opens and closes an opening in a building by raising and lowering the screen 3. In this case, the winding box 6 is disposed at the upper or lower end of the opening in the building, and the winding roller 4 is attached 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 Winding box 11 First Bracket 12 Second Bracket 13 Bearings 14 Movable crosspiece 19 Locking member 24 Bearing holder 25 Bearing holder 29 Drum shaft 30 wire 30A single wire section 30B Double track section 30a solid wire 30b One wire of a double-wire section 30c The other wire of the double-wire section 34 Coil spring 40 Winding drum 41a Large diameter part 41b Small diameter section 41c Flange 45 Fitting groove 46 Wire locking hole d1 Diameter of the winding start end of the winding drum d2 Diameter of the small diameter part of the winding drum (end of winding) D1 Screen roll diameter D2 Winding roller Outer diameter h Depth of fitting groove r Radius of curvature of the arc w1 Width of the partition 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 or close the screen, the operating force adjustment mechanism is a screen device having 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, 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 side of the building opening, and a coil spring disposed inside the winding roller and whose one and other ends are connected to the winding roller and drum shaft, which is twisted by the relative rotation between the winding roller and the drum shaft to accumulate an urging force and applies the accumulated urging force to the winding roller and drum shaft as a rotational force in the direction of winding up the screen and wire, The winding drum is shaped like a truncated cone and has a large diameter portion that serves as a winding start end when winding the wire, and a small diameter portion that serves as a 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 shape, The fitting groove is arc-shaped, the depth of the fitting groove is greater than the radius of curvature of the arc, and the width of the partition wall separating adjacent fitting grooves is smaller than the groove width of the fitting groove. A screen device characterized by:

2. 2. 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.

3. The screen device according to claim 1, 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.

4. The screen device according to claim 1, 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.

5. 2. The screen device according to claim 1, 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.

6. 2. 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