Shielding device

Abstract

To provide a shielding device capable of suppressing abnormal noise generation associated with a ball chain operation.SOLUTION: A horizontal blind includes an operation unit 20 disposed on a head box 11 that supports slats in a suspended manner. The operation unit 20 includes a pulley 22, a ball chain 21 that is hung on the pulley 22, and a housing 23. The housing 23 includes an upper opening 24A and a lower opening 24B for pulling out the ball chain 21 to the front of the head box 11, and a lower guide surface 26A that guides the ball chain 21 between a lower end of the pulley 22 and the lower opening 24B. The ball chain 21 includes a first ball portion 21A1 and a second ball portion 21A2 that are adjacent to each other. During operation of the ball chain 21, when the first ball portion 21A1 contacts the pulley 22, the second ball portion 21A2 contacts the lower guide surface 26A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a shielding device.

Background Art

[0002] In a horizontal blind which is an example of a shielding device, a lifting cord is attached to a bottom rail provided at the lower part of a shielding material suspended and supported from a head box. The horizontal blind includes a winding shaft that winds and rewinds the lifting cord, and an operation unit that rotates the winding shaft by a user's operation. The operation unit includes a pulley that transmits a rotational force to the winding shaft, an operation cord that rotates the pulley, and a cord gate that pulls out the operation cord from the head box. For example, Patent Document 1 discloses a shielding device that uses a ball chain as an operation cord.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the shielding device as described above, the ball chain may swing up and down unintentionally when the ball chain is operated. In this case, abnormal noise may occur when the ball chain contacts the cord gate.

Means for Solving the Problems

[0005] The shielding device for solving the above problems includes a shielding material and a head portion for suspending and supporting the shielding material. The head portion includes an operation unit for operating the shielding material. The operation unit includes a pulley for operating the shielding material by rotation, a ball chain engaged with the pulley, and a guide member having an upper opening and a lower opening for pulling out the ball chain in front of the head portion. The guide member includes a guide surface for guiding the ball chain such that a portion where the lower opening side is higher than the lower end side of the pulley is included in a movement path between the lower end of the pulley and the lower opening in the ball chain. The ball chain includes a plurality of ball portions connected via a connecting portion. The plurality of ball portions include a first ball portion and a second ball portion adjacent to each other. When the first ball portion contacts the pulley during operation of the ball chain, the second ball portion contacts the guide surface.

[0006] In the above shielding device, it may be configured to include the ball portion that simultaneously contacts both the pulley and the guide surface during operation of the ball chain. In the above shielding device, the guide surface is a lower guide surface, and the guide member includes an upper guide surface for guiding a portion located between the upper end of the pulley and the upper opening in the ball chain. The upper guide surface may be configured to protrude forward from an outer surface facing forward in the head portion.

[0007] In the above shielding device, the guide surface may be configured to include a curved surface portion extending upward from the lower end side of the pulley toward the lower opening side. In the above shielding device, the shielding material may be slats arranged in the vertical direction.

[0008] In the above shielding device, it may be configured to include an arc-shaped rear guide surface covering a portion located between the upper end and the rear end of the pulley in the ball chain.

Effect of the Invention

[0009] According to the present invention, it is possible to suppress the generation of abnormal noise associated with the operation of the ball chain.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0011] An embodiment of the shielding device will be described with reference to FIGS. 1 to 6. [Overall Configuration] As shown in FIG. 1, a horizontal blind 10 which is an example of the shielding device includes a head box 11, a ladder cord 12, slats 13, a bottom rail 14, and a lifting cord 15.

[0012] The head box 11 includes a housing portion 11A having a U-shaped cross-section in a side view with an open upper surface. The head box 11 is attached to an attachment portion such as a ceiling, a window frame, or a curtain box. The head box 11 is an example of the head portion provided in the shielding device. The head box 11 suspends and supports the slats 13.

[0013] The ladder cord 12 hangs down from the head box 11. The ladder cord 12 includes a pair of vertical threads and horizontal threads spanned between the pair of vertical threads. A plurality of the horizontal threads are provided along the vertical direction, which is the elevating direction of the horizontal blind 10, between the pair of vertical threads. Each of the horizontal threads provided along the vertical direction between the pair of vertical threads supports the slat 13.

[0014] The slat 13 is an example of a shielding material for shielding solar radiation and the like. The slat 13 has an elongated rectangular thin plate shape. The slat 13 is tiltably supported by the horizontal threads provided between the pair of vertical threads. The horizontal blind 10 includes a plurality of slats 13 arranged along the vertical direction.

[0015] The bottom rail 14 is a weight member for maintaining the state in which a plurality of slats 13 have descended. The bottom rail 14 is disposed below the lowermost slat 13 among the plurality of slats 13. The lower ends of the pair of vertical threads in the ladder cord 12 are connected to the bottom rail 14. In FIG. 1, a configuration in which two ladder cords 12 are provided is illustrated, but the number of the ladder cords 12 is not limited, and the number necessary for supporting the slats 13 may be provided.

[0016] The lifting cord 15 hangs down from the head box 11 in the vicinity of the ladder cord 12. The lifting cord 15 is inserted through an insertion hole (not shown) provided at the center in the short side direction of each slat 13. The lower end of the lifting cord 15 is connected to the bottom rail 14. When the lifting cord 15 is pulled up, the bottom rail 14 is pulled up, so that the plurality of slats 13 rise so as to stack on the bottom rail 14. The number of the lifting cords 15 is not limited, and the number necessary for lifting and lowering the slats 13 may be provided.

[0017] The head box 11 includes a drive shaft 16, a cord support device 17, and an operation unit 20. The drive shaft 16 is a square shaft extending in the longitudinal direction of the head box 11. The drive shaft 16 is connected to the cord support device 17 and the operation unit 20. The drive shaft 16 transmits the rotational force applied from the operation unit 20 to the cord support device 17.

[0018] The cord support device 17 has a plurality of mechanisms for supporting the ladder cord 12 and the lifting cord 15. Specifically, the cord support device 17 includes a tilt portion, a winding portion, and a delay unit.

[0019] The tilt portion is connected to the drive shaft 16 so as not to be relatively rotatable. The ladder cord 12 is engaged with the tilt portion. When the tilt portion rotates in conjunction with the drive shaft 16, one vertical thread of the ladder cord 12 rises and the other vertical thread descends. Thereby, the angle of the slat 13 is adjusted.

[0020] The winding portion has a cylindrical shape. The winding portion is connected to the drive shaft 16 via a delay unit. The lifting cord 15 is wound around the outer periphery of the winding portion. The winding portion winds and rewinds the lifting cord 15 by rotating in conjunction with the drive shaft 16.

[0021] The delay unit includes a stopper device that restricts the rotation of the drive shaft 16 so as to prevent the self-weight descent of the slat 13 and the bottom rail 14. Further, when the drive shaft 16 rotates by more than the amount of rotation required for the tilt operation of adjusting the angle of the slat 13, the delay unit operates to rotate the winding portion in conjunction with the drive shaft 16.

[0022] The cord support device 17 may include an obstacle detection device. When the bottom rail 14 collides with an obstacle when the slat 13 is lowered, the obstacle detection device stops the rotation of the winding portion to stop the descent of the slat 13 and the bottom rail 14.

[0023] [Operation unit 20] As shown in FIG. 1, the operation unit 20 is disposed at one end of the accommodation portion 11A in the head box 11. One end of the drive shaft 16 is connected to the operation unit 20.

[0024] The operation unit 20 includes a ball chain 21. The ball chain 21 is drawn forward from the head box 11 (the front side of the paper surface in FIG. 1). In the horizontal blind 10, the drive shaft 16 rotates by operating the ball chain 21. Then, various operations such as tilting, rising, and lowering of the slat 13 are performed by the rotation of the winding shaft and the tilt portion of the cord support device 17 in response to the rotation of the drive shaft 16. Here, the front refers to the indoor side direction opposite to the outdoor side direction such as a window when viewed from the horizontal blind 10.

[0025] The ball chain 21 includes a plurality of ball portions 21A and a connecting portion 21B that connects two ball portions 21A to each other. The ball portions 21A are intermittently arranged via the connecting portion 21B. The ball chain 21 is configured in an endless (circular) chain shape by connecting a plurality of ball portions 21A via the connecting portion 21B.

[0026] As shown in FIG. 2, the operation unit 20 includes a pulley 22. The pulley 22 includes a shaft hole 22A to which the drive shaft 16 is connected. The shaft hole 22A is a square hole corresponding to the drive shaft 16. The pulley 22 transmits the rotation for operating the slat 13 to the drive shaft 16 connected to the shaft hole 22A. Note that the pulley 22 may transmit the rotation to the drive shaft 16 via other members such as a speed reduction unit and a brake member instead of directly transmitting the rotation to the drive shaft 16.

[0027] The pulley 22 includes convex portions 22B and concave portions 22C that are alternately arranged in the circumferential direction. The convex portions 22B correspond to the tooth portions of the gear-shaped pulley 22. The concave portions 22C correspond to the tooth groove portions of the gear-shaped pulley 22. The ball portions 21A of the ball chain 21 are engaged with the concave portions 22C of the pulley 22.

[0028] The operation unit 20 includes a housing 23. The housing 23 is an example of a guide member that regulates the movement path (movement locus) of the ball chain 21 engaged with the pulley 22.

[0029] The housing 23 includes an upper opening 24A and a lower opening 24B for pulling out the ball chain 21 in front of the head box 11. The upper opening 24A and the lower opening 24B are arranged vertically. The portion of the ball chain 21 engaged above the pulley 22 is pulled out in front of the head box 11 from the upper opening 24A. The portion of the ball chain 21 engaged below the pulley 22 is pulled out in front of the head box 11 from the lower opening 24B.

[0030] The housing 23 includes an upper guide piece 25. The upper guide piece 25 separates the upper opening 24A and the lower opening 24B in the housing 23. The upper surface of the upper guide piece 25 faces the upper opening 24A. The lower surface of the upper guide piece 25 faces the lower opening 24B.

[0031] The upper surface of the upper guide piece 25 functions as an upper guide surface 25A. The upper guide surface 25A guides the ball chain 21 so that the movement path of the portion located between the upper end of the pulley 22 and the upper opening 24A in the ball chain 21 draws a smooth curve. The upper guide surface 25A protrudes forward from the outer surface 11S1 facing forward in the head box 11.

[0032] The housing 23 includes a lower guide piece 26. The upper surface of the lower guide piece 26 faces the lower opening 24B. The upper surface of the lower guide piece 26 functions as a lower guide surface 26A. The lower guide surface 26A includes a curved surface portion that extends upward from the lower end side of the pulley 22 toward the lower opening 24B side.

[0033] The lower guide surface 26A guides the ball chain 21 so as to include a portion where the side of the lower opening 24B is higher than the lower end side of the pulley 22 in the movement path of the ball chain 21 between the lower end of the pulley 22 and the lower opening 24B. In other words, the lower guide surface 26A guides the ball chain 21 so as to include a portion where the position of the ball chain 21 becomes higher from the lower end side of the pulley 22 toward the lower opening 24B side.

[0034] The housing 23 includes a guide wall 27. The guide wall 27 includes an arcuate rear guide surface 27A that covers at least a portion of the ball chain 21 located between the upper end and the rear end of the pulley 22. The rear guide surface 27A of the guide wall 27 guides the ball chain 21 so that the movement path of the ball chain 21 between at least the upper end and the rear end of the pulley 22 forms a smooth curve, particularly an arc.

[0035] Note that the rear guide surface 27A may include an arcuate portion that extends forward from the upper end of the pulley 22 toward the upper opening 24A. The rear guide surface 27A may include an arcuate portion that extends downward and forward from the rear end of the pulley 22. For example, the rear guide surface 27A is configured in an arc shape having a central angle of 90 degrees or more and 180 degrees or less.

[0036] [Operation of the operation unit 20] As shown in FIG. 2, in the operation unit 20, by pulling the ball chain 21 led out from the upper opening 24A downward, the pulley 22 rotates in the first direction D1 (counterclockwise in FIG. 2). As a result, the slat 13 and the bottom rail 14 are raised. Conversely, in the operation unit 20, by pulling the ball chain 21 led out from the lower opening 24B downward, the pulley 22 rotates in the second direction D2 (clockwise in FIG. 2). As a result, the slat 13 and the bottom rail 14 are lowered.

[0037] When the pulley 22 rotates by the operation of the ball chain 21, the ball chain 21 includes two ball portions 21A adjacent to each other, namely, a first ball portion 21A1 in contact with the pulley 22 and a second ball portion 21A2 in contact with the lower guide surface 26A. In other words, when the first ball portion 21A1 contacts the pulley 22 during the operation of the ball chain 21, the second ball portion 21A2 contacts the lower guide surface 26A.

[0038] As shown in FIG. 3, when the pulley 22 rotates by the operation of the ball chain 21, the ball portions 21A of the ball chain 21 are in a state of contacting both the pulley 22 and the lower guide surface 26A. Hereinafter, the ball portion 21A that contacts both the pulley 22 and the lower guide surface 26A simultaneously is defined as a third ball portion 21A3.

[0039] The third ball portion 21A3 is located between a fourth ball portion 21A4 in contact with the pulley 22 and a fifth ball portion 21A5 in contact with the lower guide surface 26A. That is, in the ball chain 21, when the third ball portion 21A3 contacts both the pulley 22 and the lower guide surface 26A simultaneously, the fourth ball portion 21A4 contacts the pulley 22 and the fifth ball portion 21A5 contacts the lower guide surface 26A.

[0040] When pulling the ball chain 21 led out from the upper opening 24A downward, the third ball portion 21A3 corresponds to a state where it has moved in the first direction D1 so that the second ball portion 21A2 in FIG. 2 contacts both the pulley 22 and the lower guide surface 26A. In this case, the first ball portion 21A1 in FIG. 2 corresponds to the fourth ball portion 21A4 that contacts the pulley 22 in FIG. 3.

[0041] That is, when pulling the ball chain 21 led out from the upper opening 24A downward, the ball portion 21A of the ball chain 21 contacts the lower guide surface 26A at the position of the lower opening 24B. Then, when the pulley 22 rotates in the first direction D1, the ball portion 21A changes from a state of contacting only the lower guide surface 26A to a state of contacting both the pulley 22 and the lower guide surface 26A simultaneously. Further, when the pulley 22 rotates in the first direction D1, the ball portion 21A changes from a state of contacting both the pulley 22 and the lower guide surface 26A simultaneously to a state of contacting only the pulley 22.

[0042] Also, when pulling the ball chain 21 led out from the lower opening 24B downward, the third ball portion 21A3 corresponds to a state where the first ball portion 21A1 in FIG. 2 has moved in the second direction D2 so as to contact both the pulley 22 and the lower guide surface 26A. In this case, the second ball portion 21A2 in FIG. 2 corresponds to the fifth ball portion 21A5 that contacts the lower guide surface 26A in FIG. 3.

[0043] That is, when pulling the ball chain 21 led out from the lower opening 24B downward, the ball portion 21A of the ball chain 21 contacts the pulley 22 at the lower end of the pulley 22. Then, when the pulley 22 rotates in the second direction D2, the ball portion 21A changes from a state of contacting only the pulley 22 to a state of contacting both the pulley 22 and the lower guide surface 26A simultaneously. Further, when the pulley 22 rotates in the first direction D1, the ball portion 21A changes from a state of contacting both the pulley 22 and the lower guide surface 26A simultaneously to a state of contacting only the lower guide surface 26A.

[0044] [Cross-sectional Shape of the Head Box 11 and Tilting of the Slat 13] As shown in FIG. 4, the bottom 11B of the head box 11 includes a first concave groove 11C, a second concave groove 11D, and a rib 11E. The first concave groove 11C, the second concave groove 11D, and the rib 11E extend parallel to each other along the longitudinal direction of the head box 11.

[0045] The first concave groove 11C and the second concave groove 11D are arranged in the front-rear direction via the rib 11E. In FIG. 4, in the front-rear direction, the first concave groove 11C is located on the front side of the rib 11E, and the second concave groove 11D is located on the rear side of the rib 11E. The first concave groove 11C, the second concave groove 11D, and the rib 11E are provided across the housing 23 of the accommodating portion 11A and the operation unit 20 in the head box 11.

[0046] The first concave groove 11C and the second concave groove 11D are recessed upward from the reference plane 11S2 provided by the bottom 11B. The rib 11E has a flat surface at its tip (lower end) that is slightly lower than the reference plane 11S2. The flat surface of the rib 11E may be a curved surface. Note that the reference plane 11S2 is the bottom surface provided by the portion of the bottom 11B other than the first concave groove 11C, the second concave groove 11D, and the rib 11E. In FIG. 4, the height of the reference plane 11S2 is indicated by the dashed line L1.

[0047] The accommodating portion 11A has a line-symmetric shape with the center line CL1 in the front-rear direction as the axis of symmetry. That is, in the accommodating portion 11A, in the front-rear direction, the rib 11E is located at the center of the bottom 11B. Also, in the accommodating portion 11A, the first concave groove 11C and the second concave groove 11D have a line-symmetric shape with the center line CL1 as the axis of symmetry.

[0048] As shown in FIG. 5, when tilting the slat 13 in the direction where the front end E1 of the slat 13 is located above the rear end E2, the uppermost slat 13 is configured to be tiltable until the front end E1 reaches a position above the tip of the rib 11E. At this time, the front end E1 of the uppermost slat 13 is located inside the first concave groove 11C. Note that in FIGS. 5 and 6, the height of the tip of the rib 11E is indicated by the dashed line L2.

[0049] As shown in FIG. 6, when tilting the slat 13 in the direction where the rear end E2 of the slat 13 is located above the front end E1, the uppermost slat 13 is configured to be tiltable until the rear end E2 reaches a position above the tip (dashed line L2) of the rib 11E. At this time, the rear end E2 of the uppermost slat 13 is located inside the second concave groove 11D.

[0050] Thus, by tilting the slat 13 so that the end of the uppermost slat 13 is positioned above the tip of the rib 11E, it is possible to suppress the external solar radiation from leaking between the head box 11 and the slat 13. Further, in the front-rear direction, since the first concave groove 11C and the second concave groove 11D are positioned on both sides of the rib 11E, interference between the bottom 11B of the head box 11 and the tilted slat 13 can be avoided.

[0051] The housing portion 11A has a line-symmetric shape with the center line CL1 in the front-rear direction as the axis of symmetry. Thus, when assembling the head box 11, it is not necessary to distinguish between the front and rear of the housing portion 11A, so the workability during assembly can be improved. That is, the head box 11 can also be assembled such that the first concave groove 11C is located on the rear side of the rib 11E and the second concave groove 11D is located on the front side of the rib 11E.

[0052] Also, if instead of the rib 11E, a protruding piece without a flat surface or a curved surface at its tip, such as a thin plate-like piece, is adopted, when the head box 11 is supported from below during the assembly or attachment of the head box 11, a large pressure is applied to the operator's hand. In this regard, by configuring the tip of the rib 11E with a flat surface or a curved surface, when the head box 11 is supported from below during the assembly or attachment of the head box 11, the pressure applied to the operator's hand can be dispersed and reduced.

[0053] [Operation of the Embodiment] During the operation of the ball chain 21, among two adjacent ball parts 21A, the first ball part 21A1 contacts the pulley 22, and the second ball part 21A2 contacts the lower guide surface 26A. According to the above configuration, during the operation of the ball chain 21, the ball part 21A of the portion of the ball chain 21 passing between the lower end of the pulley 22 and the lower opening 24B contacts at least one of the pulley 22 and the lower guide surface 26A.

[0054] Assume that there is a ball portion 21A of the ball chain 21 that does not contact either the pulley 22 or the lower guide surface 26A between the lower end of the pulley 22 and the lower opening 24B. In this case, in the portion of the ball chain 21 between the lower opening 24B and the lower end of the pulley 22 where the lower opening 24B side is higher than the lower end side of the pulley 22, the ball portion 21A is suspended between the pulley 22 and the lower guide surface 26A. Since the movement path of this ball portion 21A is not restricted by either the pulley 22 or the lower guide surface 26A, it is likely to swing up and down during the operation of the ball chain 21.

[0055] As a result, between the lower end of the pulley 22 and the lower opening 24B, the ball chain 21 that swings up and down unintentionally collides with the housing 23, making it easy for abnormal noises to occur during the operation of the ball chain 21.

[0056] In particular, when the pulley 22 is rotated in the first direction D1 by pulling the ball chain 21 led out from the upper opening 24A downward, it becomes difficult for the tension to be directly applied to the portion of the ball chain 21 located between the lower end of the pulley 22 and the lower opening 24B. Therefore, when the ball chain 21 led out from the upper opening 24A is pulled downward, it is considered that the ball portion 21A between the lower end of the pulley 22 and the lower opening 24B is particularly likely to swing.

[0057] In this regard, in the present embodiment, during the operation of the ball chain 21, the movement path of the ball portion 21A passing between the lower end of the pulley 22 and the lower opening 24B is restricted by contacting at least one of the pulley 22 and the lower guide surface 26A. Therefore, during the operation of the ball chain 21, it is suppressed that the ball portion 21A passing between the lower end of the pulley 22 and the lower opening 24B swings up and down unintentionally.

[0058] [Effects of the Embodiment] (1) When the ball chain 21 is operated, the portion of the ball chain 21 located between the lower end of the pulley 22 and the lower opening 24B is in contact with at least one of the pulley 22 and the lower guide surface 26A. Therefore, the movement path of the portion of the ball chain 21 located between the lower end of the pulley 22 and the lower opening 24B is restricted by the pulley 22 and the lower guide surface 26A. As a result, when the ball chain 21 is operated, the portion is prevented from swinging vertically unintentionally, so that the generation of abnormal noise associated with the operation of the ball chain 21 can be suppressed.

[0059] (2) The plurality of ball portions 21A include a third ball portion 21A3 that is in contact with both the pulley 22 and the lower guide surface 26A simultaneously when the ball chain 21 is operated. Thereby, each ball portion 21A constituting the ball chain 21 is always in contact with at least one of the pulley 22 and the lower guide surface 26A between the lower end of the pulley 22 and the lower opening 24B. Therefore, when the ball chain 21 is operated, the portion of the ball chain 21 located between the lower end of the pulley 22 and the lower opening 24B can be more preferably prevented from swinging vertically unintentionally.

[0060] (3) The upper guide surface 25A of the upper guide piece 25 protrudes forward of the outer surface 11S1 facing forward in the head box 11. By extending the length of the upper guide surface 25A forward, the movement path of the portion of the ball chain 21 passing through the upper opening 24A can be made more stable. Thereby, the generation of abnormal noise associated with the operation of the ball chain 21 can be more preferably suppressed.

[0061] (4) The lower guide surface 26A includes a curved surface portion that extends upward from the lower end side of the pulley 22 toward the lower opening 24B. Thereby, the movement path of the portion located between the lower end of the pulley 22 and the lower opening 24B can guide the ball chain 21 so as to draw a smooth curve. As a result, rattling of the ball chain 21 engaged with the pulley 22 can be suppressed, so that generation of abnormal noise associated with the operation of the ball chain 21 can be more preferably suppressed.

[0062] (5) The shielding device of the present embodiment is the horizontal blind 10 including the slats 13 arranged in the vertical direction as a shielding material. In the case of the horizontal blind 10, from the viewpoint of shielding sunlight without gaps with as few slats 13 as possible, it is preferable that the width of the slats 13 in the front-rear direction is as large as possible. Therefore, the width of the slats 13 in the front-rear direction is configured to be equal to or slightly smaller than the width (depth) of the head box 11. As a result, it becomes difficult to lead out the ball chain 21 directly below the head box 11, so it is necessary to lead out the ball chain 21 in front of the head box 11. Therefore, due to the structure of the horizontal blind 10, the above abnormal noise is likely to occur. In that regard, in the case of the horizontal blind 10 of the present embodiment, generation of abnormal noise associated with the operation of the ball chain 21 can be suppressed by the above actions and effects.

[0063] (6) The housing 23 includes an arcuate rear guide surface 27A that covers at least a portion of the ball chain 21 located between the upper end and the rear end of the pulley 22. The portion of the ball chain 21 located between the upper end and the rear end of the pulley 22 is far from the upper opening 24A and the lower opening 24B, so the tension is not easily transmitted directly. Therefore, the rear guide surface 27A guides the ball chain 21 so that the movement path of the portion draws a smooth curve. Thereby, rattling of the ball chain 21 engaged with the pulley 22 can be suppressed as a whole, so that generation of abnormal noise associated with the operation of the ball chain 21 can be more preferably suppressed.

[0064] (7) In the head box 11, while avoiding interference with the uppermost tilted slat 13 by the first concave groove 11C and the second concave groove 11D, the slat 13 can be tilted so that the end of the uppermost slat 13 is positioned above the tip of the rib 11E. Thereby, it is possible to suppress solar radiation from the outside from leaking between the head box 11 and the slat 13. Further, since the housing portion 11A has a line-symmetric shape with the center line CL1 in the front-rear direction as the axis of symmetry, it is possible to provide the above-described function while improving the workability during assembly.

[0065] (8) Since the rib 11E has a flat surface or a curved surface at its tip, when the head box 11 is supported from below during the assembly or attachment of the head box 11, the pressure applied to the operator's hand can be dispersed and reduced.

[0066] [Modified Example] This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically non-conflicting range.

[0067] · The shape and size of the rear guide surface 27A are not particularly limited as long as they can prevent the ball chain 21 wound around at least the pulley 22 from falling off the pulley 22.

[0068] · In this embodiment, the horizontal blind 10 is exemplified as the shielding device. However, the present invention is not limited to this, and any shielding device may be used as long as it uses the ball chain 21 drawn out from the head portion for the operation of the shielding material. For example, the shielding device may be a lift-up curtain, a pleated screen, a roll-up screen, a vertical blind, a vertical pleated screen, a vertical roll screen, a curtain rail, an accordion curtain, a panel curtain, or the like.

[0069] · The lower guide surface 26A is not limited to a form including a curved surface portion extending upward from the lower end side of the pulley 22 toward the lower opening 24B side, and may be a flat surface extending upward from the lower end side of the pulley 22 toward the lower opening 24B side.

[0070] · The upper guide surface 25A of the upper guide piece 25 is not limited to a configuration that protrudes forward from the outer surface 11S1 of the head box 11. For example, the upper guide surface 25A may extend from the inside of the housing 23 to the position of the outer surface 11S1 of the head box 11, or may extend from the inside of the housing 23 to a position inside the outer surface 11S1 of the head box 11.

[0071] · The ball chain 21 may be provided with adjacent first ball portions 21A1 and second ball portions 21A2 such that when the first ball portion 21A1 contacts the pulley 22 during the operation of the ball chain 21, the second ball portion 21A2 contacts the lower guide surface 26A. For example, the ball chain 21 may not include a ball portion 21A that contacts both the pulley 22 and the lower guide surface 26A at the same time. For example, a configuration in which the lower guide surface 26A is located below the ball portion 21A that contacts the pulley 22 between the lower end of the pulley 22 and the lower opening 24B in the ball chain 21 may also be used. Even in this case, the ball portion 21A separated from the pulley 22 will be in a state of immediately contacting the lower guide surface 26A located below.

[0072] · The head box 11 is not limited to a configuration including a bottom 11B having a first concave groove 11C, a second concave groove 11D, and a rib 11E, and may have any shape. · The tip shape of the rib 11E does not have to be a flat surface or a curved surface as long as it can disperse and reduce the pressure applied to the operator's hand when supporting the head box 11 from below. For example, the tip of the rib 11E may be formed of a surface provided with a large number of fine irregularities.

Description of Reference Numerals

[0073] 10… Horizontal blind 11… Head box 11S1… Outer surface 13… Slat 14… Bottom rail 16… Drive shaft 17… Cord support device 20... Operating unit 21... Ball chain 21A... Ball part 21A1 to 21A5... First ball part to fifth ball part 21B... Connecting part 22... Pulley 23... Housing 24A... Upper opening 24B... Lower opening 25A... Upper guide surface 26A... Lower guide surface 27A... Rear guide surface

Claims

1. A shielding material and a head portion for suspending and supporting the shielding material, The head portion includes an operation unit for operating the shielding material, The operation unit includes a pulley for operating the shielding material by rotation, a ball chain engaged with the pulley, and a guide member having an upper opening and a lower opening for pulling out the ball chain in front of the head portion, The guide member includes a guide surface for guiding the ball chain so as to include a portion where the lower opening side is higher than the lower end side of the pulley in the movement path between the lower end of the pulley and the lower opening in the ball chain, The ball chain includes a plurality of ball portions connected via a connecting portion, The plurality of ball portions include a first ball portion and a second ball portion adjacent to each other, When the first ball portion contacts the pulley during the operation of the ball chain, the second ball portion contacts the guide surface Shielding device.

2. Including the ball portion that contacts both the pulley and the guide surface simultaneously during the operation of the ball chain The shielding device according to claim 1.

3. The guide surface is a lower guide surface, The guide member includes an upper guide surface for guiding a portion of the ball chain located between the upper end of the pulley and the upper opening in the ball chain, The upper guide surface protrudes forward from the outer surface facing forward in the head portion The shielding device according to claim 1 or claim 2.

4. The guide surface includes a curved surface portion extending upward from the lower end side of the pulley toward the lower opening side The shielding device according to claim 1 or claim 2.

5. The shielding material is slats arranged in the vertical direction The shielding device according to claim 1 or claim 2.

6. It includes an arc-shaped rear guide surface covering a portion of the ball chain located between the upper end and the rear end of the pulley The shielding device according to claim 1 or claim 2.

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