A multi-section roll-up curtain is raised and lowered by plural support/rotational drive mechanisms disposed in a spaced manner along the length of the curtain. Each drive mechanism is symmetrically loaded with a curtain section attached to opposed sides of each drive mechanism. Each curtain section includes plural vertically spaced curtains which are simultaneously rolled-up and unrolled. Each drive mechanism includes plural vertically spaced drive motors each connected to first and second curtain-bearing roll-up tubes disposed on opposite sides of a drive motor. A generally vertical guide member is coupled to each drive motor by a respective carriage assembly allowing the drive motors to travel up in rolling up the curtains and down in unrolling the curtains. This arrangement accommodates the large torques encountered in operating long curtain sections permitting multi-section curtains 600′ and longer in length to be reliably and safely operated without using large, powerful motors.

FIELD OF THE INVENTION

This invention relates generally to multi-section roll-up curtains, where each section includes plural vertically aligned curtains which are simultaneously rolled-up and unrolled, and is particularly directed to very long, multi-section curtains and a curtain support/rotational drive arrangement capable of accommodating the large torques encountered in these types of curtains.

BACKGROUND OF THE INVENTION

A common type of flexible door employs a drive mechanism for raising and lowering the door and includes an electrically powered motor which applies torque to a roller causing the door to wind up on or to unwind from the roller in positioning the door in either the open or closed position, or any position therebetween. A common type of flexible curtain is comprised of a lightweight, strong fabric material and includes an electric motor typically connected to a roller mechanism via a reduction gear to reduce the number of revolutions of the electric motor per unit distance of travel of the flexible door in raising and lowering the door. Movable structures of this type can be used either to cover an opening, such as a doorway in a building structure, or they may be used as a movable partition, wall or curtain in the structure.

When used as a partition, or curtain, this roll-up structure may span large distances in the building structure. These types of flexible curtains isolate the inside of the building structure from the elements, such as wind, rain, snow and sunlight, while permitting the building structure to be opened up so as to provide access to the outside when the environment is more hospitable.

As the applications for these types of flexible curtains have increased, additional demands have been placed on their structure and operation. For example, these types of flexible curtains are being used to span increasingly longer distances within the building structure. This, of course, places increasing demands upon the curtain support and drive, or displacement, system. Higher power ratings are required for the curtain drive mechanism, which typically includes an electrically powered motor, for increasing heights and horizontal distances spanned by the curtain. In addition, the curtain support system, which typically includes a horizontal, elongated rod, must be stronger to accommodate the increased weight of curtains spanning larger openings and must itself be lightweight to compensate for the increased weight of the curtain. This further increases the power requirements to operate the flexible curtain. In addition, the increased weight of the curtain with longer curtain lengths gives rise to the application of large torques arising from the unwinding forces exerted by the long length of the rolled-up curtain on the curtain support/drive mechanism. This increased torque places increased stress on the curtain support structure and drive mechanism. Where a roll-up rod is attached to a lower end of the flexible curtain, a complicated displacement and support mechanism is typically required to accommodate vertical movement of the rod during curtain roll-up and unrolling.

These types of curtains are increasingly being used in dairy barns wherein large numbers of cows are maintained and housed. Roll-up curtains are particularly adapted for this type of environment because they allow for easy and quick control of air flow as well as access to the outside environment. Sufficient ventilation is important in this environment to allow warm moisture to escape, to protect the cows from drafts and cold winter air, and to keep the cows dry. The increase in the size of herds has increased the demand for larger buildings offering improved ventilation and environmental isolation characteristics. This has necessitated the adoption of curtains of longer length with corresponding increased demands on the curtain support structure and drive mechanism.

The present invention addresses the aforementioned increased demands on roll-up curtains used in various applications by providing a curtain support and drive arrangement which accommodates the increased weights of longer curtain sections forming the walls of larger structures. The curtain support and drive arrangements used in the present invention are particularly designed to accommodate the large torques encountered when operating roll-up curtains of increased length.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a multi-section roll-up curtain incorporating plural drive mechanisms arranged in a spaced manner along the length of the curtain to accommodate curtains spanning very long distances, i.e., as long as 600′ in length.

Another object of the present invention to incorporate a counter force in the rotary drive mechanism of a roll-up curtain to accommodate the large torque exerted by very long length and/or very large height curtains on the curtain support/rotary drive mechanism.

Still another object of the present invention is to reduce the mechanical stress on and prolong the operating lifetime of a rotary drive mechanism used in raising and lowering a roll-up curtain by applying the force of the curtain's weight symmetrically to the curtain support/rotary drive mechanism.

It is another object of the present invention is to provide a drive arrangement for a roll-up curtain which is easily installed, highly reliable, comprised of a small number of easily assembled components, and capable of accommodating the weight of large curtains.

This invention contemplates a roll-up curtain comprising: a first curtain section including a first fixed upper rod attached to a support structure and a second lower rod; a second curtain section including a third fixed upper rod attached to the support structure and a fourth lower rod, wherein the second curtain section is aligned with and laterally spaced from the first curtain section; a rotary drive disposed intermediate the first and second curtain sections and coupled to the second and fourth lower rods for rotationally displacing the second and fourth lower rods in a first direction for rolling up the first curtain section on the second lower rod and the second curtain section on the fourth lower rod in opening the first and second curtain sections, and for rotationally displacing the second and fourth lower rods in a second opposed direction for unrolling the first curtain section from the second lower rod and the second curtain section from the fourth lower rod in closing the first and second curtain sections; and a vertical guide engaging the rotary drive for directing the rotary drive in vertical travel upward during rolling up of the curtain sections and downward during unrolling of the curtain sections and maintaining the rotary drive a fixed distance from and in a fixed orientation relative to the first and second curtain sections during rolling up and unrolling of the curtain sections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, there is shown a perspective view of multi-section roll-up curtain assembly10in accordance with the present invention. Roll-up curtain assembly10includes first, second and third curtain sections12,14and16disposed in a laterally spaced array over an opening in a building structure. Each of the first, second and third curtain sections12,14and16includes an upper curtain and a lower curtain capable of being moved between a rolled-up position, wherein the curtain is opened, and an unrolled position, wherein the curtain sections fully cover the opening in the building structure. Thus, the first curtain section12includes an upper curtain18and a lower curtain20. The second curtain section14includes upper curtain22and lower curtain24. Finally, the third curtain section16includes upper curtain26and lower curtain28. The lower curtain20of the first curtain section12includes an upper portion20aand lower portion20b. Similarly, the lower curtain24of the second curtain section14includes upper portion24aand lower portion24b. Finally, lower curtain28includes an upper portion28aand a lower portion28b.

The opening in the building structure over which the roll-up curtain assembly10is positioned is defined by an upper support member40, a lower support member42, and a pair of lateral limits to the opening which are not shown inFIG. 1for simplicity. The upper and lower support members40,42are connected to and integral with the building structure, which also is not shown in the figure for simplicity.

Disposed within each of the aforementioned curtain sections are plural hems which extend the length of the curtain section and which are each adapted to receive a respective elongated, linear, tubular rod extending the length of the curtain section. Thus, upper curtain section22includes upper and lower hems respectively adapted to receive an upper support rod55and a lower drive rod60. Similarly, upper curtain section26includes upper and lower hems which are adapted to receive an upper support rod57and a lower drive rod62, respectively. Finally, upper curtain section18includes upper and lower hems which are adapted to receive an upper support rod56and a lower drive rod61, respectively. Each of the aforementioned upper support rods is securely attached to the upper support member40, or another structural member within the building structure, by means of a conventional connecting bracket which is not shown in the figure for simplicity.

Similarly, lower curtain24is provided with plural spaced hems which are adapted to receive an upper support rod58a, an intermediate drive rod64and a lower rod63a. Lower curtain28is adapted to receive an upper support rod58b, an intermediate or drive rod66and a lower rod63b. Finally, lower curtain20is adapted to receive an upper support rod58c, an intermediate drive rod65and a lower rod63c. Each of the aforementioned upper support rods58a,58band58cof the lower curtains is securely attached to the building structure by conventional means such as mounting brackets which are not shown in the figure for simplicity. It is in this manner that each of the lower curtains is supported by and suspending from the building structure. The weight of each of the lower rods63a,63band63cmaintains each of the lower curtains in a stretched condition when suspended from a respective upper support rod. Each of the rods disposed in each of the lower curtains extends the full length of the lower curtain. Each of the aforementioned rods is preferably comprised of a high strength, lightweight, rigid material such as structural steel or aluminum.

Disposed between and connected to each adjacent pair of upper and lower curtains is a respective curtain support/drive mechanism. Thus, a first curtain support/drive mechanism30is disposed between and connected to upper curtains18and22and lower curtains20and24of the first and second curtain sections12,14. Similarly, a second curtain support/drive mechanism32is disposed between and coupled to upper curtains22and26and lower curtains24and28of the second and third curtain sections14,16. A similar curtain support/drive mechanism is connected to the outer end of each of the end curtain sections in a manner similar to that shown inFIG. 1and described below, although this is not shown inFIG. 1for simplicity. AlthoughFIG. 1shows three curtain sections driven by two or more curtain support/drive mechanisms, a preferred embodiment of the present invention includes first and second curtain sections driven by an inner curtain support/drive mechanism located between the two curtain sections and by two outer curtain support/drive mechanisms each located on an outer end of one of the curtain sections. Individual curtain sections several hundred feet in length may be raised and lowered in this preferred embodiment to cover openings of 600′ and longer in length.

The second curtain support/drive mechanism32is shown in greater detail in the front perspective view ofFIG. 2. Curtain support/drive mechanism32includes a generally vertically oriented guide member44connected near its upper end to the upper support member40by conventional connecting brackets which are not shown in the figure for simplicity. Similarly, the lower end of vertical guide member44is securely attached to the lower support member42by means of connecting brackets68and70.FIG. 3is a perspective view illustrating additional details of an upper drive assembly100attached to the vertical guide member44.FIGS. 6 and 7are lower perspective views showing additional details of the manner in which the upper drive assembly100is attached to and is displaced along the vertical guide member44.

Each of the curtain support/drive mechanisms includes an upper drive assembly and a lower drive assembly. The upper drive assembly includes an upper electrical drive motor46, while the lower drive assembly includes a lower electrical drive motor48. The upper drive assembly100further includes a first gearbox52connected to the upper electric drive motor46, while the lower drive assembly includes a second gearbox54connected to the lower electric drive motor48. The combination of the lower electrical drive motor48and the second gearbox54is coupled to the intermediate drive rods64and66of the lower curtains24and28by suitably connecting hardware which will now be described in detail in terms of the upper drive assembly100shown inFIG. 4because the construction and operation of the upper and lower drive assemblies is identical.

Connected to the first gearbox52and rotationally driven by the upper electric drive motor46is a drive shaft102. Attached to respective ends of the drive shaft102are a first drive sprocket104and a second drive sprocket, which is not shown inFIG. 4for simplicity. Disposed about the first drive sprocket104is a first endless chain106, while disposed about the second drive sprocket is a second endless chain110. Respectively disposed above and adjacent to the first drive sprocket104and the second drive sprocket are first and second driven sprockets108and112. Endless chains106and110also respectively engage the first and second driven sprockets108and112. Thus, rotation of the drive shaft102produces a corresponding rotation of the first drive sprocket104and the second drive sprocket giving rise to a corresponding rotation of the first and second driven sprockets108and112. The first and second driven sprockets108,112are securely coupled together by means of the combination of a spacer tube114and first and second brass bushings116and118. Thus, the first and second driven sprockets108and112undergo the same rotational displacement. The first brass bushing116is securely connected to lower drive rod60of the upper curtain22of the second curtain section14as shown inFIG. 2. Similarly, the second brass bushing118is securely connected to the lower drive rod62of the upper curtain26of the third curtain section16as also shown inFIG. 2. Thus, the upper drive assembly100simultaneously rotationally displaces lower drive rods60and62in a first direction for rolling up the upper curtains and raising the two curtain sections, or in a second, opposed direction for unrolling the two upper curtains in unrolling the two adjacent curtain sections. A similar arrangement allows the lower drive assembly which includes a combination of lower electric drive motor48and second gearbox54to either roll-up the adjacent lower curtains24and28respectively onto intermediate drive rods64and66, or to unroll these curtains from the two intermediate drive rods in lowering the curtain sections. It should be noted that each of the upper and lower portions24aand24bof lower curtain24and each of the upper and lower portions28aand28bof lower curtain28are simultaneously rolled onto or unrolled from the lower drive rods64and66, respectively, during operation of the lower electric drive motor48.

While each of the lower curtains has been described and is illustrated as including an upper support rod, an intermediate drive rod and a lower rod, the present invention will work equally as well if the intermediate rod is omitted and the curtain is raised and lowered by means of its lower rod. Thus, for example, the present invention contemplates eliminating the intermediate drive rods64,65and66of lower curtains24,20and28and driving, i.e., raising and lowering, these curtains by means of a drive assembly connected to the lower rods63a,63band63cof these lower curtains. The advantage of the arrangement shown inFIG. 2where the drive arrangement is connected to an intermediate drive rod is that the upper and lower portions of each of these curtains are simultaneously rolled up on or unrolled from the rotating drive rod which reduces the time and the number of revolutions to roll-up or unroll the curtain.

As shown in the various figures, each drive assembly includes a carriage146connected to a drive motor as shown for the case of the upper electric drive motor46of the upper drive assembly100. A similar carriage arrangement is connected to the lower electric drive motor48and operates in a similar manner to allow the drive assembly to move upward and downward within the vertical guide member44as described in the following paragraphs.

Carriage146is in the form of a linear, elongated shaft of a high strength material such as structural steel and includes an inner shaft, or axle,148which extends the length of the carriage. Attached to a first end of shaft148is a first roller150, while attached to a second, opposed end of the shaft is a second roller152. Vertical guide member44includes a generally flat inner portion44cand first and second edge flanges44aand44bdisposed on opposed lateral edges thereof. Each of the edge flanges44a,44bextends outwardly from the flat inner portion44cof the vertical guide member44and forms a channel which is adapted to receive and engage a respective roller of the carriage146. Thus, the first edge flange44ais adapted to receive and engage the first roller150, while the second edge flange44bis adapted to receive and engage the second roller152. Each of the rollers150,152freely rotates on the carriage's shaft148and allows the carriage146to move vertically along the length of the vertical guide member44. Thus, as the lower drive rods60and62are rotationally displaced by the upper electric motor46of the upper drive assembly100, the combination of the upper electric motor and first gearbox152and associated hardware attached to the carriage146is free to move vertically up in the direction of arrow154and down in the direction of arrow156inFIG. 6along and within the vertical guide member44. This permits adjacent curtains to be rolled-up onto or unrolled from the two drive rods.

The larger weights of longer curtains apply increasingly larger torques to the curtain support and drive mechanism, particularly during raising of the curtain. Thus, if as shown inFIG. 6, lower drive rod62rotates in the direction of arrow92, the weight of the raised, or partially upraised, curtain will exert a torque counter to the direction of arrow92. The torque exerted by the curtain will urge the first roller150in a downward direction as shown by direction arrow94inFIG. 7and will urge the second roller152in an upward direction as shown by direction arrow96in the figure. The vertical guide member44opposes any displacement of the rollers out of the plane of the vertical guide member and ensures that the carriage146and the upper electric drive motor46attached thereto move only vertically during rolling up and unrolling of the attached curtains. In addition, the torque exerted along the lower drive rod62in the direction of arrow98shown inFIG. 6urges the carriage46and the upper electric drive motor46in a direction toward the vertical guide member44. In order to accommodate this latter torque, a third roller160shown inFIG. 7is attached to the carriage146by means of mounting bracket158. This third roller160facilitates displacement of the carriage146and upper electric drive motor46combination along the length of vertical guide member44. Third roller160thus counters the tendency of the aligned lower drive rods60and62to be rotationally displaced by the weight of the attached curtains and opposes any bending of carriage146and movement of the upper electric drive motor46toward the flat inner portion44cof the vertical guide member44.

Referring toFIG. 4, there is shown a perspective view of the combination of first and second limit switches72and74. The first limit switch72is attached to a vertical pipe, or tube,78by means of a first coupling bracket80. Similarly, the second limit switch74is attached to the vertical pipe78by means of a second coupling bracket82. The vertical pipe78is disposed within and attached to the vertical guide member44by conventional means such as connecting brackets which are not shown for simplicity. The first limit switch72includes a first pivot arm88coupled to a first sensor housing84. Similarly, the second limit switch74includes a second pivot arm coupled to a second sensor housing86. Each of the first and second pivot arms88,90is free to pivot upward or downward about its associated sensor housing. Thus, the first limit switch72provides an indication that the upper curtains22and26are in the full “DOWN” position. Another limit switch (not shown in the figures for simplicity) located in an upper portion of the roll-up curtain assembly provides an indication of the full “UP” position of the two upper curtains22,26. The second limit switch74provides an indication of the full “UP” position of the two lower curtains24,28. A third limit switch76mounted to a lower portion of the vertical pipe78as shown inFIG. 2provides an indication that the lower curtains24and28are in the full “DOWN” position. In the embodiment shown in the figures, the third limit switch76is engaged by the lower rod63aof the second curtain section's lower curtain24. In the embodiment of the present invention where the lower curtain does not include upper and lower portions with the curtain's drive rod disposed on its lower edge, the third limit switch76would be engaged by the lower curtain's drive rod located on its lower edge.

Referring toFIG. 5, there is shown a combined schematic and block diagram of a control panel50coupled to a computer controller138for controlling the operation of the roll-up curtain assembly of the present invention. The left portion of the control panel28provides control of the first curtain section12shown inFIG. 1, while the right portion of the control panel controls the operation of the second curtain section14. A third portion of the control panel50provides control for the third curtain section16shown inFIG. 1, but this is not shown inFIG. 5for simplicity. Control panel50includes first and second toggle switches130and132. The first toggle switch130allows the user to select either an automatic or manual mode of operation, or to turn the controller for the first curtain section12“OFF”. When in the “AUTOMATIC” mode of operation, the operation of the first curtain section is under the control of the computer controller138which stores a pre-programmed operating program. The second toggle switch132is operable when the first toggle switch130is in the “MANUAL” mode of operation and allows for closing and opening of the first curtain section under the control of an operator. The right portion of the control panel50which controls operation of the second curtain section14similarly includes a first toggle switch134and a second toggle switch136. The first toggle switch134allows for the user to select between “AUTOMATIC” or “MANUAL” operation of the second curtain section, or to turn the curtain controller “OFF”. The second toggle switch136allows for manually controlling the position of the first curtain section12when the first toggle switch is in the “MANUAL” mode of operation.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.