SLAT OPENING/CLOSING DRIVE MECHANISM IN SHUTTER EQUIPMENT

Abstract: In a shutter equipment (1) having a shutter (4) for opening and closing an opening portion such as a building entrance, window or the like the shutter (4) being composed of plural slats (5) positioned in a vertically adjacent relation when the shutter (4) is closed, the slats (5) being wound up and pulled down continuously to stow the slats and close the opening portion, respectively; a slat opening/closing mechanism substantially composed of vertical guide rails (3) disposed vertically on both sides of the opening portion; a box (2) positioned on top of the vertical guide rails (3) to stow the slats (5) transversely in parallel in a vertically suspended state; a pair of right and left endless chains (20) which are movable from the vertical guide rails (3) into the slat stowing box (2) and to which are secured through shafts both end faces of the upper portion of each slat (5); a vertical slat drive mechanism (36) for winding up and pulling down the chains to raise and lower the slats (5) in a suspended state from the vertical guide rails (3) toward the upper portion of the box (2) and reversely from the latter toward the former; sprockets (31, 32) engaged with the chains (20) for controlling the extended state and bent state of the chains (20) smoothly in both the opening portion opening/closing state in which the slats (5) go up and down along the vertical guide rails (3) and the stowed state with the slats (5) stowed in parallel in the box (2); and a chain-sprocket disengaging mechanism (28) for disengaging the sprockets (31, 32) and the chains (20) from each other.

Description: The present invention relates to a shutter equipment for opening and closing such openings as building entrances and windows and particularly to an improvement of a slat opening/closing drive mechanism in a shutter equipment for opening and closing a plurality of slats which constitute a shutter. The conventional shutter equipment of this type, as described in EP-A-0142564, is composed of vertical guide rails disposed on both sides of an opening for opening and closing a shutter, with a slat stowing box being provided on top of the vertical guide rails; support rails for hanging slats which support rails are disposed within the slat stowing box; a plurality of slats each provided on both sides of the upper end thereof with slat hanging rollers which are movable along the support rails and the vertical guide rails, the slats being connected to a pair of right and left chains each through the slat hanging rollers; and drive means for vertically moving each slat between the vertical guide rails through sprockets engaged with the chains and also moving each slat into the slat stowing box. The vertical slat drive means is mounted rotatably within the slat stowing box and it has a long rotative shaft engaged with the paired chains and rotated by means of, for example, a geared motor. Upon operation of the vertical slat drive means in one direction, its rotational force is transmitted to the rotative shaft of the drive means and the sprockets are driven rotatively, whereby the slats in the slat stowing box are pulled out successively to the opening between the vertical guide rails through the chains and go down. In this way the slats are arranged in the form of a single vertical plane to close the opening between the vertical guide rails. On the other hand, upon operation of the vertical slat drive means in the opposite direction, the slats arranged between the vertical guide rails go up successively into the slat stowing box, in which the slat hanging rollers mounted on both sides of the upper end of each slat come into engagement with the upper surfaces of the support rails, whereby the slats are suspended in a parallel, folded condition. More specifically, the vertical slat drive means has a first rotative shaft which is driven by means of, for example, a geared motor and a second rotative shaft for moving the slats up and down interlockedly with the first rotative shaft. On the first rotative shaft are mounted a second sprocket interlocked through an endless chain with a first sprocket which is integral with an output shaft of the geared motor, a pair of right and left, output-side, third and fourth sprockets for driving both the right and left chains, and a fifth sprocket on the output side for transferring the rotational force to the second rotative shaft, while on the second rotative shaft are mounted a sixth sprocket for inputting the rotational force from the first rotative shaft through the fifth sprocket and an endless chain, and a pair of right and left, seventh and eighth sprockets for winding and engaging the chains with respect to the third and fourth sprockets. When the first rotative shaft is rotated in one direction by the vertical slat drive means, its rotational force is transmitted to the second rotative shaft, whereby the slats stowed in the top box are pulled out to the opening between the vertical guide rails through the chains and go down. In this way the slats are arranged in the form of a single vertical plane to close the opening between the vertical guide rails. On the other hand, when the second rotative shaft is rotated in the opposite direction through the first rotative shaft by the vertical slat drive means, the slats arranged between the vertical guide rails go up successively into the top box, in which the slat hanging rollers positioned on both sides of the upper end of each slat come into engagement with the upper surfaces of the support rails, whereby the slats are suspended in a parallel, folded condition. The support rails are each formed by bending a metallic plate in the channel shape in section, and the shaft portion of the slat hanging roller is brought into rolling engagement with the upper end of the vertical wall portion on one side of the channel. Consequently, the concentric roller portion of a larger diameter connected integrally with the above roller shaft portion floats from the support rail and it functions as a rotation stopping flange portion to prevent the roller shaft portion from being disengaged from the upper surface of the support rail. In the slat opening/closing drive mechanism of the above conventional shutter equipment, however, the chains are engaged with the sprockets inside the bent portions extending from the vertical guide rails in the slat stowing direction within the top box and as many as eight sprockets in all are used, so if the sprockets are disposed in proximity to the upper corner portions in the box, the chains engaged with the sprockets come too close to the inner wall of the box, resulting in interference of the chains and slats with the inner wall, and thus there occur inconveniences in the shutter opening and closing operation. Therefore, the sprockets cannot be disposed in proximity to the upper corner portions in the top box or the slat stowing box, resulting in that a dead space is formed in the box. So the internal space cannot be utilized effectively and the entire equipment becomes larger in size, causing increase of the cost. In the slat opening/closing drive mechanism of the above conventional shutter equipment, moreover, since the rotative shaft is supported only at both end portions thereof despite of it being a long shaft, the rotative shaft deflects and a slat moving in the slat stowing box interferes with the rotative shaft, whereby the rotation of the rotative shaft is prevented, so that the slats can no longer be operated smoothly for its opening or closing motion. Further, in the above conventional shutter equipment, only both side portions of the upper end of each slat are supported on the support rails in a suspended state through the slat hanging rollers and the lower portion of the slat is free. As the slat hanging rollers roll on the support rails in this state, the slats move in a vertical posture, so if the slats are moved at high speed, they will be deflected largely due to wind pressure. Such deflections cause the slats to interfere with each other, giving rise to a loud noise and flaw of the slats, thus requiring decrease of the slat moving speed. In such conventional shutter slat hanging and supporting mechanism, the shaft portion of each slat hanging roller is supported in linear contact with the upper end of the vertical wall portion on one side of the support rail and the thickness of the said vertical wall portion corresponds to only the thickness of the metallic plate, that is, it is very thin, so that a considerable load including the weight of each slat acts concentratively on the vertical wall portion. Consequently, both the vertical wall portion and the roller shaft portion wear out in an early stage, thus resulting in loss of durability. Further, the slat hanging rollers and the support rails must be formed of a metal to ensure strength sufficient to withstand the above concentrated load, thus leading to increase of the cost inevitably and causing a loud metallic noise during rolling of the rollers. The present invention aims to overcome the various problems encountered in the conventional shutter equipment described above. According to the present invention there is provided a slat drive mechanism for a shutter equipment having vertical guide rails disposed on both sides of a shutter opening and provided with a slat stowing box, and a plurality of slats movably retained by and between said vertical guide rails and interconnected by a pair of flexible right and left chains which are movable into the slat stowing box, the slats being movable between a pulled-out position in which the slats are disposed adjacent to each other in the form of a single vertical plane between the vertical guide rails and a stowed position in which said slats are disposed in said box, comprising: a vertical slat drive means for moving the slats vertically along said vertical guide rails, a first sprocket connected to an output shaft of said vertical slat drive means, a second sprocket mounted on a rotative shaft disposed in said box and an endless chain drivingly connecting said second sprocket with said first sprocket; characterised by third and fourth sprockets mounted respectively on each end of said rotative shaft, said third and fourth sprockets being disposed in the vicinity of chain-sprocket disengaging means for bending and moving the flexible chains, wherein a lower portion of each of said third and fourth sprockets drivingly engages with the outside of a bent portion of one of said flexible chains. An embodiment of the present invention is now described, by way of example only, with reference to the accompanying drawings, in which:- Fig. 1 is a front view of the whole of a shutter equipment according to an embodiment of the present invention; Fig. 2 is a side view thereof; Fig. 3 is an enlarged front view of a slat connected to chains; Fig. 4 is a side view thereof; Fig. 5 is a sectional view taken on line V-V of Fig. 3; Fig. 6 is an enlarged side view in longitudinal section of a slat stowing box; Fig. 7 is an enlarged view of the portion where a chain-sprocket disengaging means is mounted; Fig. 8 is a sectional view taken on line VIII-VIII of Fig. 6; Fig. 9 is an enlarged transverse sectional view of a vertical guide rail (3); Fig. 10 is a constructional diagram of a vertical slat drive system; Fig. 11 is a sectional view of the portion where a sprocket rotating shaft is mounted; Fig. 12 is a sectional view taken on line XII - XII of fig. 11; and Fig. 13 is an enlarged sectional view taken on line XIII-XIII of Fig. 7. A shutter equipment 1 shown in Figs. 1 and 2 is provided with a shutter stowing box 2 disposed horizontally on top of a shutter opening/closing opening such as a building entrance or window, a pair of right and left vertical guide rails mounted vertically on both sides below the box 2, and a shutter 4 mounted vertically movably between the vertical guide rails 3. The shutter 4 is constituted by a plurality of interconnected slats 5. The slats 5 are held adjacent each other in a closed state in the form of a single vertical plane between both vertical guide rails 3, while in the box 2 they are suspended in a parallel, folded state as shown in Fig. 6. More specifically, in this embodiment, each slat 5 has an upper frame 6, a lower frame 7 and vertical frames 8 on both sides, as shown in Figs. 3 and 4. The upper and lower frames 6 and 7 are formed by roll forming of a metallic plate of a light metal such as aluminum or steel and they have such sectional shape as shown in Fig. 5, for example. In more particular terms, by roll forming of the above metallic plate the upper and lower frames 6 and 7 are integrally formed with main slat plate portions 9, 10, upper and lower reinforcing ribs 11 and 12 projecting to the back side, the ribs 11 and 12 being formed by depression in a laterally long slot shape of the surface side of each of the main slat plate portions 9 and 10, a fitting convex portion 13 formed along the upper end face of the upper frame 6, and a fitting concave portion 14 formed along the lower end face of the lower frame 7. The upper and lower frames 6 and 7 are disposed in spaced relation in parallel with each other and the paired right and left vertical frames 8 having a -shaped section are fitted in and connected fixedly to both right and left end portions of the upper and lower frames 6 and 7, whereby a main portion of the slat 5 is assembled. As a result of the above assembly there is formed a window opening 15, and behind the window opening 15 is mounted a window frame 16 between the reinforcing ribs 11 and 12. A transparent plate 18 is fitted in and held by the window frame 16 through an elastic ring 17. The slats 5 constructed as above are connected at equal intervals to a pair of right and left chains 20 on both sides of the respective upper ends through a long pin 19 as shown in Figs. 3, 4, 8, 9 and 13. As to the construction of the chains 20, in the conventional construction in which a pair of inside link plates 21 and a pair of outside link plates 22 are connected together through a bushing 23 and a link pin 24 and like connections stretch successively, the link pin 24 located in the mounting position of the slat 5 is removed from the bushing 23 and the long pin 19 is inserted therein rotatably. The chains 20 are vertically driven in engagement with later-described sprockets 31 and 32 of the vertical slat drive system, whereby the plural slats 5 are moved up and down along the vertical guide rails 3 located on both sides in a suspended state through the chains 20. On the fore end side of each long pin 19 is mounted a slat hanging upper roller 25 rotatably. Further, at the lower end portions on both sides of each slat 5 are rotatably journalled lower rollers 26 serving as both a lifting guide and a deflection preventing means each in a biased position rearward from the center of each chain 20. On the other hand, within the box 2 is provided a chain looseness detector 27 in the vicinity of the upper end of each vertical guide rail 3 as shown in Fig. 6. The chain looseness detector 27 has the function of detecting the force of bending of each chain 20 caused by overlapping, stagnation, etc. of the slats 5 in the vertical guide rails 3, a warning function at the time of the detection, or an automatic stopping function for a later-described vertical slat drive means 36 (see Figs. 6 and 10). Within the box 2, as shown in Figs. 6 and 7, there are disposed a slat hanging and stowing support rail 29 which is connected on the fore end side thereof to the upper end of each vertical guide rail 3 through a chain-sprocket disengaging means 28, as well as a chain fore end guide bar 30 disposed above in parallel with the support rail 29. The chain-sprocket disengaging means 28 functions to guide and move the chain 20 in a bent condition between the upper end of each vertical guide rail 3 and the fore end of each support rail 29. It comprises an outside chain disengaging plate 28A and an inside chain disengaging plate 28B. The chain disengaging plates 28A and 28B form a chain bending guide passage 28C therebetween. In the chain bending guide passage 28C, as shown in Fig. 13, the outside of the inner and outer link plates 21 and 22 of the chain 20 is in sliding contact with the outside chain disengaging plate 28A, while on the opposite side the bushing 23 of the chain 20 is in sliding contact with the inside chain disengaging plate 28B, whereby the chain 20 is bent and moved smoothly. The support rail 29 is inclined downwards gradually toward the rear side distant from the chain-sprocket disengaging means 28, and the upper roller 25 of the chain 20 past the chain bending guide passage 28C comes into rolling engagement with the support rail 29, whereby the slats 5 are suspended in a parallel, folded state. As shown in Fig. 8, the support rail 29 comprises a bottom portion 29a and both side wall portions 29b and 29c rising from the bottom portion, one side wall portion 29b being secured to an inner side wall of the box 2. On the other hand, the upper roller 25 comprises a roller shaft portion 25a connected coaxially to the fore end of the long pin 19 and a roller portion 25b connected integrally with the roller shaft portion 25a. The outer peripheral surface of the roller portion 25b is engaged with the upper surface of the bottom portion 29a of the support rail 29 in the state of face contact. By such face contact of the roller portion 25b with the bottom portion 29a there is obtained a sufficient strength even when the upper roller 25 is integrally formed of a synthetic resin, not a metal. Consequently, there are attained reduction of the wear between the roller portion 25b and the bottom portion 29a, improvement of durability, decrease of noise and reduction of the cost. The fore end of the chain 20 is loosely fitted movably on the chain fore end guide bar 30, allowing the chain 20 to move following the slat 5. Further, on both sides of the upper portion in the box 2, a pair of left and right chain driving sprockets 31 and 32 are journalled rotatably in the vicinity of the chain-sprocket disengaging means 28. The sprockets 31 and 32 are integrally connected coaxially by a rotative shaft 33. As shown in Fig. 10, the rotative shaft 33 comprises rotative shaft portions 33a and 33b of a small diameter supported on both side walls of the box 2 each rotatably through a bearing 34 and with the sprockets 31 and 32 integrally mounted thereon, and a cylindrical shaft portion 33c of a large diameter which interconnects the small-diameter rotative shaft portions 33a and 33b coaxially, integrally. The rotative shaft 33 is considerably long, corresponding to the length of each slat 5, so it is heavy and deflects easily. This deflection causes interference of the rotative shaft 33 with the upper end portion of the slat 5 being guided and moved along the chain bending guide passage 28C and so there is fear of a smooth movement of the slat 5 being impeded. To prevent this, an intermediate part of the large-diameter cylindrical shaft portion 33c is supported rotatably by a U-shaped support member 35 as shown in Figs. 10 to 12, thereby preventing deflection of the rotative shaft 33, that is, preventing the slat 5 from being impeded in its movement by the rotative shaft 33. The support member 35 is clamped with nuts N through an intermediate reinforcing frame 2a in the box 2 as shown in Figs. 11 and 12. The support member 35 may be welded at both end portions to the intermediate reinforcing frame 2a, and the intermediate part of the large-diameter cylindrical shaft portion 33c may be supported by the support member 35 in a bearing. The chains are in engagement with the sprockets 31 and 32. More specifically, as shown in Figs. 6, 7 and 13, the outside of the bent portion of each chain 20 bent in the chain bending guide passage 28C is engaged by the sprocket 31 or 32. By such a way of engagement, the sprockets 31 and 32 can be disposed in close proximity to the upper corner portions in the box 2, resulting in that the dead spaces in the vicinity of the sprockets 31 and 32 in the box 2 can be diminished. The sprockets 31 and 32 are rotated forward and reverse by a vertical slat drive means 36 which is shown in Figs. 6 and 8. The vertical slat drive means 36 comprises a geared motor secured to one inner side wall of the box 2, and an endless chain 39 is wound round both a first sprocket 37 on the output side mounted on the output shaft of the geared motor and a second sprocket 38 on the input side fitted on one small-diameter rotative shaft portion 33a of the rotative shaft 33, whereby the vertical slat drive means 36 and both sprockets 31, 32 are interlocked with each other. Thus, the sprockets 31 and 32 serve as third and fourth sprockets which rotate integrally with the rotative shaft 33. In lower positions in the box 2, moreover, there are disposed slat deflection preventing lower rails 40 in parallel with the support rails 29, as shown in Figs. 6 and 8. Each lower rail 40 is connected at its front end to each vertical guide rail 3 on the inlet side of the box 2 and it has a slat guide portion 41 which is inclined in the same direction as the chain bending guide passage 28C. When the upper rollers 25 of each slat 5 move in engagement with the upper surfaces of the support rails 29, the lower rollers 26 of the slat move in engagement with the lower surfaces of the lower rails 40, whereby the slat 5 is moved while being held in a vertical posture between the lower rails 40 and the support rails 29 to prevent deflection of the slat 5. The operation of the above embodiment will now be described. The upper rollers 25 of each slat 5 are supported on the support rails 29 in the box 2 and the lower rollers 26 are engaged with the lower surfaces of the lower rails 40, whereby the slats 5 are folded and suspended in parallel with one another. When in this stowed state the vertical slat drive means 36 is started to rotate in one direction, the rotative shaft 33 rotated in one direction through the first sprocket 37 on the output side, the endless chain 39 and the input sprocket 38. And by the third and fourth sprockets 31 and 32 rotating integrally with the rotative shaft 33, the chains 20 which interconnect the slats 5 held between the support rails 29 and the lower rails 40 are delivered from above to both vertical guide rails 3. As a result, the slats 5 go down successively to the respective positions to close the opening such as a window between the vertical guide rails 3. Now the shutter is in use. When in this state the vertical slat drive means 36 is started to rotate in reverse, the chains 20 go up along the vertical guide rails 3 and enter the box 2. In this case, the upper rollers 25 of each slat 5 come into engagement with the upper surfaces of the support rails 29 through the chain bending guide passages 28C of the chain-sprocket disengaging means 28. At the same time, the lower rollers 26 of each slat 5 come into engagement with the lower surfaces of the lower rails 40 through the slat guide portions 41 of the lower rails 40 and move in this sense. Consequently, the deflection of each slat 5 is prevented, and as the slats 5 shift onto the support rails 29, they are stowed in the box 2 successively in a folded and suspended state. As explained in detail hereinabove, the following various effects are attained according to the slat opening/closing drive mechanism in the shutter equipment of the present invention. Firstly, according to the present invention, only four sprockets are needed in comparison with the prior art requiring eight sprockets. Thus, the number of sprockets required decreases to half and the structure becomes extremely simple, that is, the number of assembling steps decreases to a great extent, resulting in that there can be attained reduction of cost and also reduction in size of the entire equipment. Secondly, according to the present invention, a plurality of slats are interconnected bendably and the chains which move up and down along the vertical guide rails and which are bent and guided in the incoming and outgoing direction in the slat stowing box by the chain-sprocket disengaging means, are each engaged at the outside of the bent portion thereof with the lower portion of a sprocket of the vertical slat drive system, so even when such sprockets for both chains are disposed near the inner wall surface of the slat stowing box, the chains are held in positions largely spaced from that close position, resulting in that the chains and the slats will never interfere with the inner wall surface of the box. Besides, since the chains are each held in the state of engagement with the sprocket positively by the chain-sprocket disengaging means, the slats can be operated for opening and closing motion smoothly and positively and it becomes possible to dispose the sprockets of the vertical slat drive system in positions close to the inner wall of the box, for example in upper corner portions of the box, resulting in that the inside space of the box can be utilized effectively and so the reduction in size and cost of the entire equipment can be attained. Thirdly, according to the present invention, since an intermediate part of the long sprocket rotating shaft mounted in the slat stowing box is supported rotatably by a support member, the deflection of the sprocket rotating shaft can be prevented by the said support member, so that the moving slats in the box will no longer interfere with the said rotating shaft, thus permitting smooth and positive movement of the slats in the opening and closing directions. Fourthly, according to the present invention, support rails for engagement therewith of the slat hanging rollers at the upper portion of each slat and lower rails for engagement therewith of the lower rollers are disposed in the slat stowing box so that at the time of stowage of slats into the box and also at the time of delivery thereof from the same box the slat hanging rollers and the lower rollers roll in engagement with the support rails and the lower rails, respectively. Consequently, the slats are prevented from being deflected by, for example, wind pressure and interfering with each other during movement in the slat stowing box. So the occurrence of noise and flaw caused by deflection of the slats is prevented and it becomes possible to effect a smooth and fast opening and closing operation of the slats. Also in the vertical slat drive means, the number of sprockets decreases to half in comparison with the prior art so the structure is simplified whereby the reduction in cost and in size of the entire equipment can be attained. Fifthly, according to the present invention, during movement of the slats in the slat stowing box, the slat hanging rollers at the upper portion of each slat are brought into engagement with the upper surfaces of the support rails, whereupon the lower rollers of the slat come into engagement with the lower rails, so that the slat moves while being supported at its upper and lower end portions. Consequently, the deflection of the slat caused by wind pressure is prevented and the interference of the slats with each other as well as the resultant noise or flawing is prevented, permitting the slat to move in its opening and closing directions smoothly at high speed. Sixthly, according to the present invention, a plurality of slats are interconnected bendably and chains which move up and down along the vertical guide rails and which are bent and guided in the incoming and outgoing direction in the slat stowing box by the chain-sprocket disengaging means, are each engaged at the outside of its bent portion with the lower portion of a sprocket of the vertical slat drive system, so even when the sprocket is disposed close to the inner wall surface of the slat stowing box, the chains are held in positions spaced larger than that close distance, so that the chains and the slats are prevented from interfering with the inner wall surface of the box. Besides, since the engagement of the chains with such sprockets of the vertical slat drive system is maintained positively by the chain-sprocket disengaging means, the slats can be operated for opening and closing motion smoothly and positively and it becomes possible to place the sprockets in positions close to the inner wall surface of the slat stowing box, for example in upper corner portions, thus permitting effective utilization of the internal space of the box and consequent reduction in size and cost of the entire equipment.

Claims: A slat drive mechanism for a shutter equipment (1) having vertical guide rails (3) disposed on both sides of a shutter opening and provided with a slat stowing box (2), and a plurality of slats (5) movably retained by and between said vertical guide rails (3) and interconnected by a pair of flexible right and left chains (20) which are movable into the slat stowing box (2), the slats (5) being movable between a pulled-out position in which the slats (5) are disposed adjacent to each other in the form of a single vertical plane between the vertical guide rails (3) and a stowed position in which said slats (5) are disposed in said box (2), comprising: a vertical slat drive means (36) for moving the slats (5) vertically along said vertical guide rails (3), a first sprocket (37) connected to an output shaft of said vertical slat drive means (36), a second sprocket (38) mounted on a rotative shaft (33) disposed in said box (2) and an endless chain (39) drivingly connecting said second sprocket (38) with said first sprocket (37); characterised by third and fourth sprockets (31, 32) mounted respectively on each end of said rotative shaft (33), said third and fourth sprockets (31, 32) being disposed in the vicinity of chain-sprocket disengaging means (28) for bending and moving the flexible chains (20), wherein a lower portion of each of said third and fourth sprockets (31, 32) drivingly engages with the outside of a bent portion of one of said flexible chains (20). A slat drive mechanism according to claim 1, wherein said slat drive means (36) comprises a motor and said first sprocket (37) is concentrically mounted on the output shaft of said motor. A slat drive mechanism according to claim 1 or claim 2, wherein an intermediate part of said rotative shaft (33) is rotatably supported by a supporting member (35) arranged in said box (2).

Inventors: KASAI, MASANORI
Applicants: BUNKA SHUTTER CO., LTD, LUMITTER INDUSTRY CO., LTD.
Application year: 1987
Main classification: E06B9
IPC codes: E06B9