Sheet shutter

Abstract

To provide a sheet shutter capable of detecting slack of a sheet at an early stage and reliably preventing the occurrence of a folded portion of the sheet.SOLUTION: A sheet shutter comprises a sheet-shaped curtain that opens and closes by ascending and descending between a pair of left and right side rails, and a winding drum for the curtain. The sheet shutter includes slack sensing means for detecting slack of the curtain when a contact switch is turned ON by being directly pushed by a disorderly wound portion of the curtain generated on the winding drum rotating in the curtain unwinding direction, as a result of an obstruction of the descending movement during descent of the curtain. The contact switch is provided on the mounting surface side of the curtain.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sheet shutter that partitions or opens a space inside an opening or a body such as a house, building, warehouse, factory, underground shopping mall, or the loading platform of a vehicle.

Background Art

[0002] As a conventional sheet shutter, as shown in FIG. 7, a sheet-like curtain 4 that moves up and down and opens and closes between a pair of left and right side rails 1, 1, a winding drum 3 provided in a curtain storage box 2, and a peripheral portion of the winding drum 3 are arranged. When the downward movement of the curtain 4 is inhibited during its descent, there is an elastically recoverable movable member 17 for detecting slack that is pushed by a curtain entanglement portion generated on the winding drum 3 that is rotating in the curtain lowering direction, and a switch 18 that is turned on by the movable member 17 when the movable member 17 is pushed by the curtain entanglement portion to prevent the winding drum 3 from rotating in the curtain lowering direction (see Patent Document 1). Note that FIG. 7(a) is a side cross-sectional view of the curtain storage box 2 portion, and FIG. 7(b) is a perspective view of the entire sheet shutter. In FIG. 7(a), the right side is the front side of the sheet shutter, and the left side is the mounting surface side of the sheet shutter.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the curtain 4 of the sheet shutter shown in Fig. 8(a) continues to descend, as shown in Fig. 8(b), the weight 15 at the lower end of the curtain 4 during the descending operation abuts against the obstacle S. When a curtain entanglement part 4a in the swelling direction on the winding drum 3 occurs due to the continuous rotation of the winding drum 3 after this abutment, when the movable member 17 is pushed by the curtain entanglement part 4a and the movable member 17 operates the switch 18 to turn it ON, control is performed so as not to rotate the winding drum 3 in the curtain lowering direction. Specifically, when the curtain entanglement part 4a occurs, it is configured to immediately stop or reversely drive and control the winding drum 3. The sheet shutter described in such Patent Document 1 can prevent the curtain 4 from being folded at the curtain entanglement part 4a by immediate stop, and can easily untangle the curtain entanglement part 4a by reversely driving the winding drum 3. In Figs. 8(a) and (b), the right side is the front side of the sheet shutter, and the left side is the mounting surface side of the sheet shutter.

[0005] In the sheet shutter described in Patent Document 1, the movable member 17 for detecting the occurrence of the curtain entanglement portion 4a is an elastically recoverable bent plate that is bent in a band shape covering the curtain winding portion as shown in FIG. 7(a). One end of this bent plate is fixed to the bottom of the curtain storage box 2, and the other end located above is a free end. Then, as the movable member 17 is pushed by the curtain entanglement portion 4a generated on the front side of the sheet shutter (see also FIG. 8(b)), the slack detection switch 18 disposed apart from the outside of the free end of the movable member 17 is turned on, and it is configured to detect contact of the sheet shutter with the obstacle S. There is a reason for trying to catch the generated curtain entanglement portion 4a on the front side of the sheet shutter. As shown clearly in FIG. 8(b), although the swelling of the curtain also occurs on the mounting surface side of the sheet shutter, its size is small. Also, above the winding drum 3, since it is greatly affected by gravity, it does not swell greatly upward. Accordingly, the excess portion that the sheet shutter cannot be fed out due to contact with the obstacle S is wrinkled to the front side, and the gravity acting downward is also involved, so that there is a tendency to swell greatly on the front side of the sheet shutter. Taking advantage of this tendency and aiming to detect accurately, the shape and arrangement of the movable member 17 are set.

[0006] However, in recent years, with the expansion of the application scenarios of the sheet shutter and the diversification of the types of sheet materials used, it has been found that there are cases where problems cannot be solved even with reverse driving. When bulging is detected on the front side of the sheet shutter, a folding portion has already occurred in the sheet on the mounting surface side of the sheet shutter, and even if reverse driving is performed, a situation where it is wound up with the folding portion generated will occur. Against this background, in recent years, the application scenarios of sheet shutters have expanded, such as using sheet shutters for partitioning boundaries in factories where there is usually no wind, and from the perspective of convenience in factory use, semi-transparent sheets that are more flexible than the opaque sheets that have been widely used in the past have been used, etc., and there have been changes in the sheet material. Even if there is usually no wind, there may be a temporary flow of wind due to transient environmental changes in the factory. In that case, for flexible and lightweight sheets, even a slight wind becomes a resistance, and even without obstacles, the feeding of the sheet may be inhibited and the sheet may stop. Also, due to the flexible sheet, folding portions may occur in a narrow range that does not occur in sheets with more body, and once a folding portion has occurred, it tends not to be easily eliminated with the help of the viscosity of the sheet. Thus, it has been found that the detection timing is late if the bulging is sensed on the front side of the sheet shutter. Placing a bending plate on the front side of the sheet shutter to accurately sense the slack of the sheet has actually delayed the appropriate detection timing.

[0007] An object of the present invention is to address such problems, and it is an object to provide a sheet shutter that enables early detection of sheet slack and can surely prevent the occurrence of folding portions in the sheet.

Means for Solving the Problems

[0008] To achieve such an object, the technical means according to the present invention at least comprises the following configuration.

[0009] A sheet shutter having a sheet-like curtain that moves up and down and opens and closes between a pair of left and right side rails, and a winding drum for the curtain, wherein when the downward movement of the curtain is inhibited during the downward movement of the curtain, a contact switch directly pushed by a curtain entanglement portion generated on the winding drum rotating in the curtain unwinding direction is turned on, and it has a slack detection means for detecting the slack of the curtain, and the contact switch is provided on the mounting surface side of the curtain.

Advantages of the Invention

[0010] By having such features, the present invention has the following operational effects. It is possible to provide a sheet shutter that can detect sheet slack at an early stage and reliably prevent the occurrence of folded portions of the sheet.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an example of an embodiment of the sheet shutter according to the present invention will be described with reference to the drawings. However, the following drawings are created for the purpose of explanation, and for the sake of clarity, there may be cases where members unnecessary for the explanation are not intentionally shown. Also, for the purpose of explanation, members may be intentionally shown larger or smaller, and they are not drawings showing accurate scales. In the following description, the same reference numerals in different figures indicate parts having the same function, and duplicate explanations in each figure are omitted as appropriate.

[0013] <Embodiment> (Overall Configuration) Fig. 1 is a side sectional view showing an example of the sheet shutter according to the embodiment of the present invention. Here, the cross-section is the cross-section at a position near the right end in the front view of the sheet shutter. Fig. 2 is an enlarged view of part A in Fig. 1, showing the contact switch. Fig. 3 is a side sectional view showing an example of the sheet shutter according to the embodiment of the present invention, showing a situation where slack has occurred in the curtain. Fig. 4 is an enlarged view of part B in Fig. 3, showing a state where the slack part of the curtain is in contact with the contact part provided at the tip of the whisker of the contact switch. Fig. 5 is a front view showing an example of the sheet shutter according to the embodiment of the present invention. Fig. 6 is an enlarged cross-sectional view showing the side edge portion of the curtain and the curtain guide groove of the sheet shutter according to the embodiment of the present invention, where Fig. 6(a) is a diagram showing the actual engagement state, and Fig. 6(b) is an explanatory diagram showing the relationship in terms of design dimensions.

[0014] The sheet shutter according to an embodiment of the present invention is not provided at the opening of the partition indoors or outdoors, but is basically assumed to be used in a relatively gentle space such as an interior partition in a factory. It includes a pair of left and right side rails 1 arranged on both sides of the space for opening and closing the sheet shutter, a curtain storage box 2 arranged across the upper ends of these side rails 1, a winding drum 3 arranged in this curtain storage box 2, a sheet-like curtain 4 wound around this winding drum 3 and moving up and down between the two side rails 1 by rotating the winding drum 3, a control unit 5, and a motor and a gear mechanism (not shown) for transmitting rotation to the winding drum 3.

[0015] When opening the opening provided in the housing or the like, the sheet shutter according to an embodiment of the present invention rotates the winding drum 3 by a drive mechanism (not shown) to wind up the sheet-like curtain 4 and open the opening. Also, when closing the opening provided in the housing or the like, when the connection between the winding drum 3 and the gear mechanism (not shown) of the motor (not shown) is released, the curtain 4 naturally falls due to the mass of the weight (for example, ballast, etc.) 15 provided at its front end, the winding drum 3 rotates freely, and the sheet-like curtain 4 in the curtain storage box 2 is fed out, whereby the opening is closed by the curtain 4. Since this embodiment is used indoors and is not assumed to be used under strong winds, a lightweight and soft semi-transparent sheet is adopted as the sheet-like curtain 4.

[0016] The control unit 5 is, for example, an electric circuit composed of a microcomputer, a storage device, a relay circuit, etc., and operates according to a program stored in advance. A contact switch 16 and other sensors described later are electrically connected to this control unit 5 to appropriately control the motor and the gear mechanism.

[0017] As shown in Fig. 1, the left and right side rails 1, 1 are hollow members having vertically long curtain guide grooves 10 on their opposing surfaces. Specifically, Fig. 6, which is an enlarged cross-sectional view showing the side edge portion of the curtain and the curtain guide groove, will also be used for explanation. Fig. 6(a) is a view showing the actual engagement state, and Fig. 6(b) is an explanatory view showing the relationship in terms of design dimensions. As shown in Fig. 6(a), the side edge portion 41 of the curtain 4 is bead-shaped, while the curtain guide groove 10 is C-shaped so as to wrap around the bead, preventing the side edge portion 41 of the curtain 4 from slipping out. However, if the curtain 4 is hung down without any force acting on it, the side edge portion 41 of the curtain 4 will be in a position overlapping the curtain guide groove 10, that is, the width of the curtain 4 is set to be larger than the distance between the curtain guide grooves 10 on both sides, as shown in Fig. 6(b). In other words, due to the engagement between the side edge portion 41 of the curtain 4 and the curtain guide groove 10 as shown in Fig. 6(a), the curtain 4 hangs down in a state with a certain margin in the width direction without being in a tension state. The existence of this margin prevents the descent of the curtain 4 from being inhibited when a slight wind pressure occurs in the factory. However, when the wind pressure exceeds a certain magnitude, the descent of the curtain 4 is easily inhibited by the friction caused by the prevention of the side edge portion 41 of the curtain 4 from slipping out by the curtain guide groove 10, and the curtain 4 stops. In fact, even in a situation where the operator in the factory cannot feel the wind pressure at all, the curtain 4 may stop descending. However, since the winding drum 3, which has been rotating freely until then, has inertia, the feeding out of the curtain 4 will continue. And because it is lightweight, soft, and semi-transparent (not very heavy), if an attempt is made to catch the slack of the curtain 4 on the front side of the sheet shutter, there is a risk that folded portions will already occur in the sheet-like curtain 4 due to a delay in the timing of slack detection. Therefore, in this embodiment, the configuration of the contact switch is improved from the conventional one so as to detect the slack before the folded portion occurs. Hereinafter, the configuration of the contact switch will be described.

[0018] (Configuration of the contact switch) In the sheet shutter according to an embodiment of the present invention, the contact switch 16 for detecting the slack of the curtain 4 caused by the stop of the curtain 4 is a limit switch that senses direct contact with the curtain 4. In the contact switch 16, a roller-shaped contact portion 161 is provided at the tip of the beard as shown in FIG. 2. The contact portion 161 is roller-shaped and has a smoothed surface so as not to apply more resistance than necessary to the movement of the curtain 4 while sensing contact with the curtain 4.

[0019] As shown in FIGS. 1, 3, and 5, the contact switch 16 is disposed in the curtain storage box 2. More specifically, as shown in FIG. 1, the contact switch 16 is on the mounting surface side of the curtain 4 in the peripheral portion of the winding drum 3 and near the height position of the horizontal plane where the central axis of the winding drum 3 is located, and is disposed at a position slightly separated from the outermost diameter of the winding drum 3. Further, as shown in FIG. 5, the contact switch 16 is disposed at two locations near the left and right ends of the curtain 4 in a front view of the sheet shutter. The reason for disposing at both the left and right ends is for wiring efficiency. However, for example, if problems with wiring can be solved by some means such as configuring the control unit to receive signals from the contact switch by wireless communication, three or more contact switches may be provided. For example, a contact switch may also be provided at the central position in a front view of the sheet shutter.

[0020] When the curtain 4 normally moves downward, the contact switch 16 is in the OFF state as shown in FIGS. 1 and 2. On the other hand, when the downward movement of the curtain 4 is inhibited and the curtain 4 becomes slack, the contact switch 16 becomes ON as shown in FIGS. 3 and 4. However, even if the downward movement of the curtain 4 is inhibited, due to the soft material, the slack does not immediately occur across the entire width of the curtain 4, and the slack may occur only on one side. Therefore, the contact switch 16 is disposed at two locations near the left and right ends of the curtain 4 when viewed from the front of the sheet shutter. The logical sum of the signals of the two contact switches 16 is input to the control unit 5, and the control unit 5 that has received at least one ON signal executes control to fix the winding drum 3 or to drive it in reverse.

[0021] The reason why the contact switch 16 is disposed near the height position of the horizontal plane where the central axis of the winding drum 3 is located is that the curtain 4 is most likely to bulge at the position where the reaction force from below through the curtain 4 whose downward movement is inhibited overlaps with the tangent of the winding drum 3. However, it is also possible to intentionally create the height position where the curtain 4 is most likely to bulge and dispose the contact switch 16 at that height position. For example, by providing an arc-shaped guide that can rotate along the curtain with a slight distance from the outermost diameter of the winding drum 3 and providing a relief portion that deletes a part of the guide at a specific height position, the curtain 4 can bulge outward at the relief portion. By appropriately setting the height position of the relief portion and shifting the height position where the contact switch is disposed, the limited space in the curtain storage box 2 can be effectively utilized.

[0022] (Operation of the Embodiment) The operation of this embodiment will be described. In the curtain open state where the curtain 4 is wound up by the take-up drum 3, the contact switch 16 and the curtain 4 existing at the outermost diameter of the take-up drum 3 are separated, and the take-up drum 3 is stopped. In this state, when the fixed state of the take-up drum 3 is released, due to the mass of the weight (for example, ballast, etc.) 15 provided at its front end, the curtain 4 naturally falls, the take-up drum 3 rotates freely, and the sheet-shaped curtain 4 in the curtain storage box 2 is fed out. When there is a temporary wind pressure due to a slight environmental change in the factory, if the wind pressure occurs during the descent of the curtain 4, the curtain 4 is pulled in one direction by the wind pressure, and due to the friction between the curtain guide groove 10 and the side edge portion 41 of the curtain 4, the descent of the curtain 4 is easily inhibited and the curtain 4 stops. However, since the rotating take-up drum 3 tries to continue rotating due to inertia, a curtain winding disorder site 4a due to the swelling of the curtain 4 occurs at the curtain winding portion of the take-up drum 3, and the contact portion 161 of the contact switch 16 is directly pushed by this curtain winding disorder site 4a (see Fig. 4). When the feeding amount of the curtain 4 is small, since the contact switch 16 is arranged at a position slightly separated from the maximum diameter of the take-up drum 3, when the downward movement is inhibited, the curtain 4 immediately contacts the contact portion 161 of the contact switch 16. When the feeding amount of the curtain 4 is large, although the diameter of the take-up drum 3 becomes smaller, the free rotation of the take-up drum 3 increases in speed from the previous descent amount of the curtain 4, the inertia also increases, and the reaction force generated by the inhibited downward movement is also large. Therefore, the curtain 4 bulges greatly outward, and eventually, the curtain 4 contacts the contact portion 161 of the contact switch 16.

[0023] However, when the curtain 4 stops, there may be a case where slack occurs only on one side without spreading across the entire width of the curtain 4 immediately. Therefore, in the present embodiment, the contact switches 16 are arranged at two locations near the left and right ends of the curtain 4 in the front view of the sheet shutter, and the logical sum of the signals of the two contact switches 16 is input to the control unit 5. When any one of the contact switches 16 is turned on, the control unit 5 that has received the ON signal controls to instantaneously connect the gear mechanism between the winding drum 3 and the motor. Alternatively, it may be configured to execute control to immediately reverse drive following the connection of the gear mechanism between the winding drum 3 and the motor.

[0024] As described above, when the contact switch 16 is turned on due to the curtain jamming portion 4a, it is possible to adopt a mode of automatically stopping the winding drum 3 and a mode of reverse driving following the automatic stop. Even in the mode of automatic stop, further entrainment of the curtain jamming portion 4a by the winding drum 3 is prevented at the stop time. For this reason, no folding portion occurs in the curtain jamming portion 4a. However, in the mode of reverse driving, by rotating the winding drum 3 in the curtain winding-up direction, the winding drum 3 winds up the curtain jamming portion 4a of the curtain winding portion. As a result, the curtain 4 is wound up by the winding drum 3 while the curtain jamming portion 4a is being unwound. These two modes can be configured as separate modes. However, since the two modes are differences in control modes, both modes may be provided so that the operation mode can be changed by setting. In this way, by being able to prevent the occurrence of the curtain folding portion, it is possible to prevent the curtain winding-up upper limit position (operation origin position) set in the control system of the sheet shutter from being disrupted due to the curtain folding portion, and the reliability of the sheet shutter is improved.

[0025] <Another Embodiment> The embodiment described above includes a motor and a gear mechanism for transmitting rotation in the winding-up direction to the winding drum 3. When the rotation transmission is released, the curtain 4 naturally drops due to the mass of the counterweight 15, the winding drum 3 rotates freely, and the sheet-like curtain 4 in the curtain storage box 2 is paid out. On the other hand, in another embodiment, the winding drum 3 is configured to be rotationally driven not only in the winding-up direction but also in the pay-out direction. Further, the sheet-like curtain is made of an opaque material and has a stiffer texture than the semi-transparent sheet of the previous embodiment. Therefore, when the winding drum 3 is rotated in the pay-out direction of the curtain, the curtain feeds itself out and descends faster. Since the curtain has stiffness, it is less likely to cause the problem of the curtain folding due to a delay in slack detection. However, in terms of quickly detecting that the fast-dropping curtain contacts an obstacle or the like, providing a contact switch on the mounting surface side of the curtain also has sufficient significance in another embodiment.

[0026] <Summary> As described above, the above embodiments disclose the following inventions. (1) A sheet shutter including a sheet-like curtain that moves up and down and opens and closes between a pair of left and right side rails, and a winding drum for the curtain, wherein when the downward movement of the curtain is inhibited during the descent of the curtain, a contact switch directly pushed by a curtain entanglement portion generated on the winding drum that is rotating in the curtain winding-down direction is turned on, thereby having a slack detection means for detecting the slack of the curtain, and the contact switch is provided on the mounting surface side of the curtain. (See FIGS. 3 and 4). (2) The sheet shutter according to (1), wherein the contact switches are arranged at a plurality of locations including at least near both the left and right ends. (See FIG. 5). (3) The sheet shutter according to (1) or (2), wherein the contact switch is arranged at a height position where the sheet-like curtain is most likely to bulge outward. (See paragraph 21) (4) The contact switch is disposed in the vicinity of the height position of the horizontal plane where the central axis of the take-up drum is located, and the sheet shutter according to any one of (1) to (3) is characterized thereby. (See FIG. 3). (5) The sheet-like curtain is a semi-transparent sheet, and the sheet shutter according to any one of (1) to (4) is characterized thereby. (See FIG. 5). (6) The sheet-like curtain is retained in the left and right curtain guide grooves of the sheet shutter, and the entire width thereof is set to be larger than the interval between the left and right curtain guide grooves, and the sheet shutter according to any one of (1) to (5) is characterized thereby. (See FIG. 6). (7) When the contact switch is turned on, the rotation of the take-up drum is stopped, and the sheet shutter according to any one of (1) to (6) is characterized thereby. (See paragraph 23) (8) When the contact switch is turned on, the take-up drum is driven in the curtain winding-up direction, and the sheet shutter according to any one of (1) to (6) is characterized thereby. (See paragraph 23) (9) When the contact switch is turned on, it is possible to select by setting whether to perform control to stop the rotation of the take-up drum or to perform control to drive the take-up drum in the curtain winding-up direction, and the sheet shutter according to any one of (1) to (6) is characterized thereby. (See paragraph 24) (10) The take-up drum is configured to be rotationally driven in the winding-up direction, but to rotate freely by the weight of the curtain in the pay-out direction, and the sheet shutter according to any one of (1) to (9) is characterized thereby. (See paragraph 15) (9) The take-up drum is configured to be rotationally driven in both the winding-up direction and the pay-out direction, and the sheet shutter according to any one of (1) to (9) is characterized thereby. (See paragraph 25)

[0027] As described above, the sheet shutter according to the embodiment and another embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and even if there are design changes and the like within the scope not departing from the gist of the present invention, they are included in the present invention. For example, in the embodiment, since it is a lightweight and soft semi-transparent sheet, the curtain has no firmness and slack may occur unevenly on one side. Therefore, the contact switches are arranged at two positions on the left and right. However, like in another embodiment, if the curtain has a certain degree of firmness and there is no risk of uneven slack, the contact switch may be arranged on either the left or the right, or one may be arranged in the center. Also, the drive system by the motor and the gear mechanism may be composed of a ratchet mechanism and a pawl for automatic stop.

Explanation of Reference Numerals

[0028] 1 Side rail 2 Curtain storage box 3 Take-up drum 4 Curtain 41 Side edge part 4a Entangled part 5 Control unit 10 Curtain guide groove 15 Counterweight 16 Contact switch 161 Contact part

Claims

1. A sheet shutter having a sheet-like curtain that moves up and down and opens and closes between a pair of left and right side rails, and a winding drum for the curtain, wherein when the downward movement of the curtain is inhibited during its descent, a contact switch that is directly pushed by a curtain entanglement site generated on the winding drum that is rotating in the curtain lowering direction is turned on, thereby having a slack detection means for detecting slack of the curtain, wherein the contact switch is provided on the mounting surface side of the curtain A sheet shutter characterized by the above.

2. The contact switch is arranged at a plurality of locations including at least near both the left and right ends The sheet shutter according to claim 1, characterized by the above.

3. The contact switch is arranged at a height position where the sheet-like curtain is most likely to bulge outward The sheet shutter according to claim 1, characterized by the above.

4. The contact switch is arranged near the height position of the horizontal plane where the central axis of the winding drum is located The sheet shutter according to claim 1, characterized by the above.

5. The sheet-like curtain is a translucent sheet The sheet shutter according to claim 1, characterized by the above.

6. The sheet-like curtain is retained in the left and right curtain guide grooves of the sheet shutter, and its entire width is set to be larger than the interval between the left and right curtain guide grooves The sheet shutter according to claim 1, characterized by the above.

7. When the contact switch is turned on, the rotation of the winding drum is stopped The sheet shutter according to any one of claims 1 to 6, characterized by the above.

8. When the contact switch is turned on, the winding drum is driven in the curtain winding-up direction The sheet shutter according to any one of claims 1 to 6, characterized by the above.

9. When the contact switch is turned on, it is possible to select by setting whether to perform control to stop the rotation of the winding drum or to perform control to drive the winding drum in the curtain winding-up direction The sheet shutter according to any one of claims 1 to 6, characterized by the above.

10. The winding drum is configured to be rotationally driven in the winding-up direction, but to freely rotate in the pay-out direction by the weight of the curtain The sheet shutter according to any one of claims 1 to 6, characterized by the above.

11. The take-up drum is configured to be rotationally driven in both the winding-up direction and the pay-out direction. The sheet shutter according to any one of claims 1 to 6, characterized by the above.

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