JP2713614B2 - Blind shutter opening and closing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blind shutter opening / closing device provided with upper and lower slats for automatically opening and closing a shutter opening / closing opening of a building.

[Prior art]

As a conventional blind shutter opening / closing device, a pair of left and right guide rails arranged upright on both sides of a shutter opening / closing opening, and slats connected to a plurality of upper and lower stages to move up and down along these guide rails are provided. There is one that automatically raises / lowers / opens / closes the slat. In such a conventional blind shutter opening / closing device, the upper and lower slats are each opened in a horizontal posture and moved up and down, and at the lowered position between the two guide rails, the opening and closing angle of each slat is rotationally adjusted. At the raised position between the two guide rails, each slat is stored and held in a superposed state in a horizontal posture.

[Problems to be solved by the invention]

With the conventional blind shutter opening and closing device, the upper and lower slats are automatically opened and lowered when they are in the horizontal position, and the opening and closing angle of each slat is automatically rotated at the lowered position between the two guide rails. The operation mechanism for adjusting and raising each slat in a superimposed state and the configuration of the automatic drive system become very complicated, and as a result, the entire device becomes large, and the installation location is restricted and the operation is restricted. However, there is a problem that the operation becomes complicated and the usability is deteriorated. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and automatically and smoothly performs a slat elevating operation and a slat opening / closing angle adjustment at a slat descent position by a simple series of operating mechanisms. The present invention provides a blind shutter opening / closing device which is not only capable of reducing costs by simplifying and reducing the size of the entire device, but also having no particular restriction on the installation location and having excellent usability. With the goal.

[Means for Solving the Problems]

The blind shutter opening / closing device according to the present invention includes a pair of left and right guide rails that stand on both sides of a shutter opening / closing opening, and a sprocket for slat lifting / lowering is arranged above the guide rail. The second attachment is engaged and held slidably up and down on the first attachment connected and suspended at the lower end of the chain, and the upper end is rotatable at a fixed point above the guide rail. A pair of left and right slat suspension link mechanisms that are supported and hang down in the guide rail, and whose lowermost ends are rotatably connected to the second attachment, at predetermined positions of the slat suspension link mechanism. A plurality of upper and lower cranks having a crankshaft rotatably connected thereto, and the slat suspension connected integrally with each of the crankshafts. A plurality of upper and lower slats that are horizontally supported so as to be openable and closable between link mechanisms, a movable link suspender rotatably supported on the upper part of the guide rail, and an upper end of the movable link suspender. A slat opening / closing link mechanism that is rotatably connected and suspended and hangs down in the guide rail, and that is linked to the slat suspension link mechanism via each of the cranks; Biasing means for biasing the movable link suspender in the direction, the middle of the crank arm of the lowermost bottom crank in each of the cranks, with respect to the arc guide portion provided in the second attachment, The bottom crank is engaged so as to be able to move in an arc about the crankshaft as a center of rotation.

[Operation]

In the blind shutter opening and closing device according to the present invention, the second attachment is engaged and held slidably up and down on the first attachment suspended from the lower end of the chain, and the second attachment has a slat suspension link mechanism. And the loads of the slat opening / closing link mechanism and the slats, etc., are acted on, so that the load causes the second attachment to be engaged and held at the lowered position with respect to the first attachment. In this case, the intermediate engagement portion of the bottom crank arm with respect to the arc guide portion of the second attachment is engaged with the upper end of the arc guide portion, and each slat is held in a horizontal state. Therefore, the slat lifting / lowering operation by the forward / reverse rotation drive of the sprocket is performed while each slat is in a horizontal state. Therefore, when the sprocket is rotationally driven in the lowering direction of the slat, the first attachment descends integrally with the chain, and the second attachment descends following the movement, whereby the slat suspension link mechanism is moved. Each of the slat opening and closing link mechanism extends and descends. As a result, the slats are lowered and separated from each other in the horizontal posture. Then, if the sprocket is stopped when the second attachment touches the ground, the slats are held in a horizontal posture and in a lowered state separated by a predetermined interval. When the first attachment is further lowered by the rotation of the sprocket in the lowered state, the first attachment is lowered with respect to the second attachment already in the ground state, and the first attachment at this time is moved. The lowering operation of the attachment causes the intermediate engaging portion of the bottom crank arm to move down along the arc guide portion of the second attachment. As a result, the bottom crank rotates and the other cranks also rotate via the slat opening / closing link mechanism, whereby the slats integrated with all the crankshafts rotate, and the opening and closing angles of the slats are adjusted. You. When the sprocket is reversely driven in the slat ascending direction from the slat descending state, the first attachment first moves up via the chain, and the intermediate engagement portion of the bottom crank arm follows the second attachment to follow the second attachment. Each slat is rotated in a horizontal state by raising the arc guide portion of the attachment. Then, the second attachment follows the first attachment and moves upward, so that the slats approach and ascend while maintaining the horizontal posture while the slat suspension link mechanism and the slat opening / closing link mechanism are folded. It is kept in a superimposed state.

【Example】

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 to 4, reference numeral 1 denotes a pair of left and right guide rails arranged upright on both sides of a blind shutter opening / closing opening. As shown in FIG. Slat guide hole 1a
The guide pad 1b is attached to the opening edge of the slat guide hole 1a. A storage box 2 for a slat drive system is provided above the guide rail 1. In the storage box 2, a pair of left and right sprockets 3 for raising and lowering and opening and closing the slats driven by forward and reverse rotation by a slat opening / closing mechanism (not shown) and link suspending means 4 for suspending a slat connecting link system are arranged. Have been. The sprocket 3 is meshed with a chain 5,
The chain 5 hangs down in the guide rail 1 and moves up and down by forward and reverse rotation of the sprocket 3. In the illustrated example, the chain 5 is allowed to bend in a direction along the outer periphery of the sprocket 3, but a push-pull chain is used on the opposite side to restrict the bending beyond the linearly extended state. A first attachment (elevating plate) 6 is connected to a lower end of the push-pull chain 3, and a detailed configuration of the attachment 6 will be described later. On the other hand, the link suspending means 4 includes the storage box 2.
A fixed link suspender 4A fixedly secured to the inner side wall as shown in FIG. 2 and a bent lever shape in which an intermediate portion is rotatably supported by a pin (rivet) P1 on the fixed link suspender 4A. 6B to 9 show the detailed shape and related configuration of the movable link suspender 4B. The upper end of the uppermost link 71 of the slat suspension link mechanism 7 has the pin
It is connected and suspended by P1 so as to be rotatable at a fixed point. Here, a specific illustrated configuration of the slat suspension link mechanism 7 will be described. The slat suspension link mechanism 7 is arranged such that the free end of the uppermost link 71 made of a normal flat link is
A plurality of the link 72 with the relay pawl for regulating the rotation angle and the normal relay flat link 73 are sequentially and alternately connected, and the lowermost link is provided with the lowermost pawl having the same configuration as the link 72 with the relay pawl. It has a link configuration in which links 74 are connected. More specifically, the uppermost link 71 and the link 72 with the next lower relay pawl are rotatably connected with a link pin (rivet) P2, and the link 72 with the relay claw and the lower flat relay link below. 73 and the crankshaft of the crank 10 described later
In the same manner, the link 72 with the relay pawl with the next lower order and the relay flat link 73 are sequentially and rotatably connected alternately with the link pin P2 and the crankshaft 10a. . Each of the plurality of relay pawl-attached links 72 and the lowermost pawl-attached link 74 has engagement pawls 72a and 74a integrally formed at its upper end in the state shown in FIGS. These engaging claws 72a and 74a respectively move the uppermost uppermost link 71 and the uppermost link 71 when the slat suspension link mechanism 7 is in a hanging and extending state at a predetermined bending angle as shown in FIGS. Each relay flat link 73 abuts and engages with one side edge. Therefore, each of the engaging claws 72a and 74a maintains the slat suspension link mechanism 7 in a hanging and extending state at a predetermined bending angle, and prevents the slat suspension link mechanism 7 from further extending in the vertical direction. It is a link rotation restricting means for restricting. As shown in FIGS. 10 and 11, an attachment mounting plate 75 is connected to a lower end portion of the lowermost link 74 via a crankshaft 11a of the bottom crank 11, which will be described later. The slat suspension link mechanism 7 configured as described above.
In the crankshaft 10a connecting the link 72 with the relay pawl and the relay flat link 73 to bend and rotate freely, and the crankshaft 11a connecting the link 74 with the lowermost pawl and the attachment mounting plate 75, The intermediate portions at both ends of the upper and lower slats 8 are integrally connected. The connecting means will be described below with reference to FIGS. 13 and 14. On the back surface of each of the slats 8, a pair of laterally engaging ridges 8a which are parallel to and separate from each other at the center thereof are integrally provided. The protruding ends of the laterally engaging ridges 8a are hook-shaped bent in relative directions. It has become. And, at the protruding end bent piece portion of the above-mentioned horizontally long engagement protruding ridge portion 8a,
Engagement grooves 12a provided on both sides of the rotating spindle connecting slat piece 12 are slidably fitted. In the slat piece 12, a square fitting projection 12b is integrally provided at the center thereof, and a notch engagement portion 12c is provided on an outer wall portion of the engagement groove 12a. . Into the fitting protrusion 12b of the slat piece 12, a horizontally long rectangular hole 13b provided in a flat mounting piece 13a integrated with the crankshafts 10a and 11a is fitted and engaged. In this state, the slat piece 12 is provided with a holding cap 14 for holding and fixing the mounting piece 13a of the crankshafts 10a, 11a between the slat piece 12 and the slat piece 12, as shown by a two-dot chain line in FIG. Mounted as possible. As shown in FIGS. 15 (A) to 15 (C), the pressing cap 14 has bent pieces 14a formed on both upper and lower sides, and an engagement claw formed by cutting out one end of the bent piece 14a. It has a configuration having a portion 14b and a one-end bent portion 14c bent near the engagement claw portion 14b side. By slidingly fitting the bent piece portion 14a of the holding cap 14 into the engagement groove 12a of the slat piece 12,
The engaging claw portion 14b is the notch engaging portion 1 of the slat piece 12.
2c is inevitably elastically engaged, and at this time, the one-end bent portion 14c of the holding cap 14 abuts against the end of the mounting piece 13a of the rotary support shaft 13 to perform a stopper function. Thus, the engagement state between the engagement claw portion 14b and the notch engagement portion 12c is reliably maintained. In this manner, the crank shafts 10a and 11a are detachably connected and fixed to the center portions of both ends of the slat 8 by the slat piece 12 and the holding cap 14. As shown in FIG. 2, FIG. 5, FIG. 17, and FIG. 18, the distal end of the crankshaft 10a is connected to the crank arm via a link between the link 72 with the relay pawl and the flat link 73. 10b is linked. In this case, as shown in FIG. 18, the connection pin P4 is pressed into the inside of the cylindrical end portion of the crankshaft 10a, so that the link 72 with the relay claws and the flat link 73 are relayed with the connection pin P4. In addition to being rotatably connected, the crankshaft 10a and the crank arm 10b are integrally connected. Further, in the case of the bottom crankshaft 11a, FIGS.
(2) As shown in the figure, the upper end of the attachment mounting plate 75 is rotatably fitted and connected, and a connection pin P5 is press-fitted inside the distal end cylindrical shaft portion as in the case of the crankshaft 10a. . The connecting pin P5 allows the bottom crankshaft 11a
At the same time, the lower end of the link 74 with the lowermost claw is rotatably connected to the distal end of the bottom crank shaft 11a and the bottom crank arm 11b. A guide pin P6 is integrally provided protruding from a middle portion of the bottom crank arm 11b. In the above, a crankpin (rivet) P7 (see FIGS. 2 and 5) for rotatably connecting a link of a slat opening / closing link mechanism 9 described later is attached to each free end of the crank arms 10b and 10b. , Fig. 10-Fig. 12, Fig. 16,
(See Fig. 17). On the other hand, a pin P3 is attached to one end of the movable link suspender 4B.
Through the uppermost link 91 of the slat opening / closing link mechanism 9
Are rotatably connected. The movable link suspender 4B is biased by a spring (biasing means) S in a direction to raise the slat opening / closing link mechanism 9. The slat opening / closing link mechanism 9 is, like the slat suspension link mechanism 7, provided with a link with a relay claw for regulating the rotation angle with respect to the free end of the uppermost link 91 formed of a normal flat link. A plurality of the relay relay links 92 and the normal relay flat links 93 are sequentially and alternately connected to each other, and a lowermost link 94 having the same shape as the relay nailed link 92 is connected as the lowermost link. I have. Here, in FIG. 1 to FIG. 3, the uppermost link
The lower end of the link 91 and the upper end of the link 92 with a relay claw are rotatably connected with a normal pin (rivet) P8.
The upper end of 93 is the crankpin P of the crank arm 10b.
7, and in the same manner, the lower relay flat link 93 and the relay hooked link 92 are sequentially rotatably connected alternately with the pin P8 and the crank pin P7, and
The lower end of the link 94 with the lowest claw is the bottom crank arm 11.
It is rotatably connected to the end of b by a crank pin P7. Therefore, the crank 10 is moved by the crank shaft 10a to the slats 8 of the slat suspension link mechanism 7 system.
And the link 72 with the relay pawl and the relay flat link 73 are coaxially connected, and the link 92 with the relay pawl and the relay flat link 93 of the slat opening / closing link mechanism 9 are rotated by the crank arm 10b. They are freely connected. It should be noted that the bottom crank 11 is composed of a link 74 with a lowermost pawl of the seven slat suspension link mechanisms and an attachment mounting plate.
75 and the link 94 with the lowermost claw of the slat opening / closing link mechanism 9 system. A second attachment (lifting plate) 16 is attached to the first attachment 6 connected to the lower end of the push-pull chain 3 so as to be slidable in the vertical direction. Therefore, a related configuration of the first attachment 6 and the second attachment 16 will be described below. First, upper and lower elevating pins 6A and 6B protruding toward the second attachment 16 are integrally provided on the first attachment 6, and a lateral cutout engagement is provided near the lower elevating pin 6B. A portion 6C (see FIGS. 3 and 19) is formed. On the other hand, the second attachment 16 is provided with an upper vertically long guide hole 16a, a lower vertically long guide hole 16b, and a vertically long arc guide hole 16c. The second attachment 16 has an upper roller
R1 and a lower roller R2 are rotatably supported on respective shafts. Then, the elevating pins 6A, 6B of the first attachment 6
Are inserted into the upper vertical guide hole 16a and the lower vertical guide hole 16b of the second attachment 16 so as to be slidable up and down, respectively, so that the second attachment 16 slides up and down with respect to the first attachment 6. Mounted freely. Accordingly, the second attachment 16 is moved up and down with respect to the first attachment 6 by strokes L1 and L2 (see FIG. 19) equivalent to the vertical dimension of the upper vertical guide hole 16a and the lower vertical guide hole 16b. It is possible to move. The strokes L1 and L2 have a relationship of L1 = L2. Also, regardless of the elevation position of the second attachment 16 with respect to the first attachment 6, the notch engagement portion 6C of the first attachment 6 and the second attachment 16
The arc guide hole 16c is always provided in a positional relationship of cross communication. In this manner, the second attachment 16 attached to the first attachment 6 has the structure shown in FIGS.
As shown in FIGS. 4 and 22, the lowermost attachment mounting plate 75 of the seven slat suspension link mechanisms is mounted and fixed. At the time of attachment, the intermediate guide pin of the bottom crank arm 11b interlocking the link 74 with the lowermost pawl of the slat suspension link mechanism 7 and the link 94 with the lowermost pawl of the slat opening / closing link mechanism 9 system. P6 is slidably inserted and engaged in the cross communication portion between the notch engaging portion 6C and the arc guide hole 16c. Therefore, the relative movement of the first attachment 6 and the second attachment 16 relative to each other causes the guide pin to move.
P6 is moved up and down along the arc guide hole 16c, and the up and down movement causes the bottom crank arm 11b to rotate about the bottom crank shaft 11a. To all the cranks 10, and their crankshafts 10a rotate in relation. Thus, the opening and closing angles of all the slats 8 are automatically adjusted. Next, the operation will be described. First, in a state in which the blind shutter is raised and opened, as shown in FIG. 16a, 16b
The second attachment 16 is lifted by engaging with the upper end of the second attachment 16. As a result, the movable link suspension 4B is
, The slat opening / closing link mechanism 9 and the slat suspension link mechanism 7 are folded, and the slats 8 are held in an open state in a horizontal posture. When the sprocket 3 is rotated in the counterclockwise direction in such a state in which the blind shutter is raised and opened, the first attachment 6 moves downward together with the push-pull chain 3, and the second attachment 16 follows the movement. Move down. The lowering operation of the second attachment 16 causes the slat suspension link mechanism 7 and the slat opening / closing link mechanism 9 to move.
Follow and extend together, each of the slats 8 sequentially descends and separates from the lowermost slat 8 in a horizontal posture, and the lower roller R2 comes into contact with the ground,
As shown in FIG. 3, each of the slats 8 is separated from the slat 8 at a predetermined interval and is in a blind shutter lowered state held at a horizontal open position. At this point, the driving of the sprocket 3 is stopped. In the lower state of the blind shutter, the movable link suspender 4B is still held in a rotationally displaced state by the urging force of the spring S, and the lifting pins 6A, 6B of the first attachment 6 and the bottom crank arm 1B are moved.
The guide pin P6 of 1b is maintained in a state of being engaged with the upper ends of the vertically long guide holes 16a, 16b and the arc guide hole 16c of the second attachment 16. In the lowering state of the blind shutter shown in FIG. 3, when the sprocket 3 is further rotated counterclockwise, the first attachment 6 moves down together with the push-pull chain 3. At this time, the second
Is stopped because the lower roller R2 is already grounded. Therefore, the elevating pins 6A, 6B integrated with the first attachment 6 move down along the vertically long guide holes 16a, 16b of the second attachment 16, and at the same time, the notch engagement portion 6C of the first attachment 6 Guide pin P6 engaged with
Moves downward along the arc guide hole 16c of the second attachment 16. In this manner, the guide pin P6 descends (moves in a descending direction) along the arc guide hole 16c, so that the bottom crank arm 11b integrally having the guide pin P6 rotates the crankshaft 11a. It rotates downward as the center of motion. By the downward rotation of the bottom crank arm 11b, each link of the slat opening / closing link mechanism 9 is pulled in the downward direction, whereby the movable link suspender 4B rotates about the pin P1 against the spring S. Then, each link of the slat opening / closing link mechanism 9 moves down. At this time, all the crankshafts 10a, 11a are rotated by the other cranks 10 being rotated in association with each link of the slat opening / closing link mechanism 9 described above. Accordingly, when the slats 8 integrally connected to the crankshafts 10a and 11a are closed and the guide pin P6 reaches the lowermost end of the arc guide hole 16c, the slats 8 are moved to the position shown in FIG. It becomes a fully closed state as shown in FIG. Therefore, in the state where the blind shutter is lowered,
In the fully closed state of the slat 8 shown in FIG. 1, the drive of the sprocket 3 is controlled by a switch operation or the like so that the guide pin P6 is held at an appropriate position in the arc guide hole 16c, and the blind is controlled. The opening / closing angle of each slat 8 can be adjusted when the shutter is lowered. Also, as shown in FIG. 4, each of the slats 8 is moved from the blind shutter lowering state in the fully closed state shown in FIG.
The sprocket 3 may be rotated clockwise in order to bring the blind shutter upward in a state of being superimposed in a horizontal posture. That is, in the state of FIG. 1, when the sprocket 3 is driven to rotate clockwise, first, the first attachment 6 moves upward via the push-pull chain 3. Thus, the elevating pin on the first attachment 6 side
6A and 6B are vertical guide holes 16 of the second attachment 16.
a, 16b as well as guide pin P6
Bottom crank arm by rising along 6c
11b is pivoted upward, and its bottom crank 11 and the other crank 10 are both pivoted upward in relation to each other.
All the slats 8 open in a horizontal posture as shown in FIG. Then, even in this state, the first attachment 6 continues the ascending operation, so that the elevating pin 6
A, 6B and the guide pin P6 are aligned with the vertically long guide holes 16a, 16
The second attachment 16 is lifted in a state where the second attachment 16 is engaged with the upper ends of the b and the arc guide hole 16c, respectively. Thus, the slat suspension link mechanism 7 and the slat opening / closing link mechanism 9 are bent and opened and moved up while the slats 8 maintain the horizontal posture, so that the slats 8 approach and overlap each other in the horizontal posture. As a result, the blind shutter rises and opens as shown in FIG.

【The invention's effect】

As described above, according to the present invention, the plurality of upper and lower slats are connected to the slat suspension link mechanism via the crankshafts of the upper and lower cranks so that the slats can be freely opened and closed, and through the respective cranks. A slat opening / closing link mechanism is linked to the slat suspension link mechanism, and a second attachment is held by a first attachment suspended on a chain that meshes with a sprocket so as to be able to move up and down.
Since the middle part of the lowermost bottom crank arm of each of the above-described cranks is engaged with the arc guide portion provided on the second attachment, a complicated operating mechanism or the like is not required, and the slat can be mounted in a horizontal state. The lifting and lowering operation and the adjustment of the slat opening / closing angle at the slat lowering position can be performed automatically and smoothly, so that the overall configuration of the apparatus is simplified and reduced in size, so that cost can be reduced and the installation location is reduced. There is an effect that there is no restriction, the usability is very good, and high reliability in performance is obtained.

[Brief description of the drawings]

FIG. 1 is a structural view showing a closed state of a slat at a slat lowering position of a blind shutter opening / closing device according to one embodiment of the present invention, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a slat lowering of FIG. FIG. 4 is an operation explanatory view showing a slat opened state at a position, FIG.
6 is a cross-sectional view of the guide rail, FIG. 6 is a front view of the link suspension means, FIG. 7 is a plan view of FIG. 6, FIG. 8 is a side view of FIG. 6, and FIG. IX-IX line enlarged sectional view, FIG. 10 is a front view of a bottom crank portion, FIG. 11 is a side view of FIG. 10, FIG. 12 is an enlarged sectional view taken along line XII-XII of FIG. 11, FIG. Is a back view of the slat, FIG. 14 is a sectional view taken along the line XIIII-XIIII of FIG. 13, FIG. 15 (A) is a back view of the holding cap, FIG. 15 (B) is a front view thereof, and FIG. ) Is the same end view, FIG. 16 is a front view of the intermediate crank portion, FIG. 17 is a side view of FIG.
18 is an enlarged sectional view taken along the line AA of FIG. 17, FIG. 19 is a front view of the lower operation elevating mechanism, FIG. 20 is a side view of FIG.
FIG. 19 is an enlarged sectional view taken along the line BB of FIG. 19, and FIG. 22 is a front view of a state in which a bottom crank is attached to the lower operation lifting mechanism shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Guide rail, 3 ... Sprocket, 4B ... Movable link hanging tool, 5 ... Chain, 6 ... First attachment, 7 ... Slat suspension link mechanism, 8 ... Slat, 9 ... Link mechanism for opening and closing slats, 10 …… Crank, 11 …… Bottom crank, 10a, 11a …… Crank shaft, 1
0b, 11b: Crank arm, 16: Second attachment, 16c: Arc guide hole (arc guide).

Claims (1)

(57) [Claims] 1. A pair of left and right guide rails erected on both sides of a shutter opening / closing opening, a slat lifting / lowering driving sprocket disposed above the guide rails, and the guide rail meshing with the sprocket. A chain attached to the lower end of the chain, a first attachment connected to and suspended from a lower end of the chain, a second attachment engaged with the first attachment so as to be slidable up and down, and the guide. A pair of left and right slat suspension link mechanisms, the upper end of which is rotatably supported at a fixed point at the upper part of the rail and hangs down in the guide rail, and the lowermost end is rotatably connected to the second attachment; A plurality of upper and lower cranks having a crankshaft rotatably connected to a predetermined portion of the slat suspension link mechanism, and integrally connected to the crankshafts; A plurality of upper and lower slats that are horizontally supported between the slat suspension link mechanisms so as to be openable and closable, a movable link suspender rotatably supported on the upper part of the guide rail, and the movable link. A slat opening / closing link mechanism that is rotatably connected and suspended at the upper end of the hanging tool and that hangs down in the guide rail and interlocks with the slat suspension link mechanism via each of the cranks; Biasing means for biasing the movable link suspender in the ascending direction of the link mechanism for, the middle of the crank arm of the lowermost bottom crank in each of the cranks,
A blind shutter opening / closing device, wherein the blind shutter opening / closing device is engaged with an arc guide portion provided on the second attachment so as to be able to move in an arc around a crank shaft of the bottom crank.