Motorized Device for Opening and Closing Curtains

Abstract

The disclosure provides a device for automatically opening and closing a pair of curtains that includes a rod with a longitudinal hollow space. The device also includes a first and second threaded shaft housed within the hollow space. First and second gears are attached to the first and second threaded shaft, respectively. The first and second gear intermesh, so that, when the first threaded shaft rotates in a first angular direction, the second threaded shaft rotates in an opposite second angular direction. The device also includes first and second threaded nuts, threaded onto the first and second threaded shafts. A motor is provided to rotate the first threaded shaft in the first angular direction and simultaneously rotate the second the shaft in the opposite second angular direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Provisional Patent Application No. 63/376,313, filed Sep. 20, 2022 and bearing the same title. The entire disclosure of the prior application is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to home automation devices, and particularly to devices for opening and closing curtains.

BACKGROUND

The proliferation of home automation devices, of late, has been remarkable. A big acceleration in the development of such devices has come with the introduction of means to control these, such smart phones running apps and smart speakers responsive to voice controls.

One popular area for automation has been in window coverings. Automated window blinds (see, e.g., U.S. Pat. No. 9,869,124) and roller shades (see, e.g., U.S. Pat. No. 10,087,680) can be found in many homes. The ability to open and close multiple units at the same time and to do it on a user-programmed schedule are welcome additions of the modern “smart home.”

While some solutions for a motorized opening and closing curtains and drapes have been available, these typically are for commercial installations and involve complex mechanisms with chains or belts or other types of actuators. As such, they can be beyond the abilities of a do-it-yourselfer to install.

SUMMARY

In a first aspect, the disclosure provides a device for automatically opening and closing a pair of curtains that includes a rod with a longitudinal hollow space and a midpoint where a leading edge of a first curtain of the pair of curtains and a leading edge of a second curtain of the pair of curtains meet when closed. The device also includes a first threaded shaft housed within the hollow space. This first threaded shaft extends from a point near one end of the curtain rod to a first point past the midpoint. A second threaded shaft is also included, within the hollow space and having the same or a different thread pitch as the first threaded shaft. The second threaded shaft extends from a point near an opposite end of the curtain rod to a second point past the midpoint. A first gear is attached to the first threaded shaft so as to rotate axially with the first threaded shaft. A second gear is attached to the second threaded shaft so as to rotate axially with the second threaded shaft. The first and second gear intermesh, so that, when the first threaded shaft rotates in a first angular direction, the second threaded shaft rotates in an opposite second angular direction. The device also includes a first threaded nut, threaded onto the first threaded shaft and configured to translate in a first direction toward the midpoint as the first threaded shaft is rotated in the first angular direction and to translate in an opposite second direction away from the midpoint as the first threaded shaft is rotated in the second angular direction. A second threaded nut is also provided that is threaded onto the second threaded shaft and configured to translate in the first direction as the second threaded shaft is rotated in the first angular direction and to translate in the opposite second direction as the second threaded shaft is rotated in the second angular direction. A first curtain linker is attached to the first threaded nut and attached near the leading edge of the first curtain, while a second curtain linker is attached to the second threaded nut and attached near the leading edge of the second curtain. A motor is provided to to rotate the first threaded shaft in the first angular direction and simultaneously rotate the second the shaft in the opposite second angular direction. The device operates to close the pair of curtains when the first threaded shaft is rotated in the first angular direction and operates to open the pair of curtains when the first threaded shaft is rotated in the opposite second angular direction.

Further aspects and embodiments are provided in the foregoing drawings, detailed description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are provided to illustrate certain embodiments described herein. The drawings are merely illustrative and are not intended to limit the scope of claimed inventions and are not intended to show every potential feature or embodiment of the claimed inventions. The drawings are not necessarily drawn to scale; in some instances, certain elements of the drawing may be enlarged with respect to other elements of the drawing for purposes of illustration.

FIG. 1 is perspective view of a pair of curtains where the device has pulled the curtains apart to reveal a window.

FIG. 2 is a perspective view of the same pair of curtains where the device has pushed the curtains together cover the window.

FIG. 3 is a perspective view of the device of the present invention in a shortened state.

FIG. 4 is a perspective view of the device of FIG. 3 that has been lengthened.

FIG. 5 is a cross-sectional view of the shortened device of FIG. 3.

FIG. 6 is a cross-sectional view of the lengthened device of FIG. 4.

FIG. 7 is perspective view of the internal moving parts of the device of FIG. 3, in the curtains closed position.

FIG. 8 is a perspective view similar to FIG. 7, except in the curtains opened position.

FIG. 9 is a closer view of the device depicted in FIG. 7.

FIG. 10 is a view similar to FIG. 9, with the threaded rods removed.

FIG. 11 is perspective view of a device for curtains having attaching rings.

FIG. 12 is a perspective view of a device for curtains having curtain hooks.

FIG. 13 is a perspective view of a device used with pocketed curtains.

FIG. 14 is a perspective view of a dual-rod device for use to open and close two sets of curtains.

FIG. 15 is a perspective view of a single-rod device for use to open and close two sets of curtains.

FIG. 16 is a perspective view of a two curtain system.

DETAILED DESCRIPTION

The following description recites various aspects and embodiments of the inventions disclosed herein. No particular embodiment is intended to define the scope of the invention. Rather, the embodiments provide non-limiting examples of various compositions, and methods that are included within the scope of the claimed inventions. The description is to be read from the perspective of one of ordinary skill in the art. Therefore, information that is well known to the ordinarily skilled artisan is not necessarily included.

Definitions

The following terms and phrases have the meanings indicated below, unless otherwise provided herein. This disclosure may employ other terms and phrases not expressly defined herein. Such other terms and phrases shall have the meanings that they would possess within the context of this disclosure to those of ordinary skill in the art. In some instances, a term or phrase may be defined in the singular or plural. In such instances, it is understood that any term in the singular may include its plural counterpart and vice versa, unless expressly indicated to the contrary.

As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. For example, reference to “a substituent” encompasses a single substituent as well as two or more substituents, and the like.

As used herein, “for example,” “for instance,” “such as,” or “including” are meant to introduce examples that further clarify more general subject matter. Unless otherwise expressly indicated, such examples are provided only as an aid for understanding embodiments illustrated in the present disclosure and are not meant to be limiting in any fashion. Nor do these phrases indicate any kind of preference for the disclosed embodiment.

The terms “curtain,” “drape,” and “drapery” can have slightly different meanings. Typically, curtains are suspended from a point above the top of a window and hang down just below the window. Drapes or draperies, in some circles, typically hang from above the window and extend to a point at or near the floor. Drapes are often made of a heavier material. Although curtains and drapes are common in residential settings, they are also used in commercial, industrial and transportation settings. For example, automated curtains may be used to separate rooms and block dust in a factory setting, such as paint rooms. Automated curtains may be used to keep cold air in a refrigerated room. Automated curtains may also be used to separate cabins in airplanes. Nevertheless, the terms “curtains,” “drapes” and “drapery” will be used interchangeably, with a preference for the word “curtain” to refer to them all in all settings.

As used herein, the term “midpoint” is intended to have a relatively broad meaning, referring to a point between the two end points. Preferably, the midpoint at which two curtains meet is the halfway point or center point between the two ends.

Now referring to FIG. 1, a device 15 is depicted for opening and closing curtains 11 and 13. The device 15 may take the place of a conventional curtain rod. Rings 17 are used to attach the curtains to the device 15. The device is mounted to the wall on the side of the window with brackets 19. As is customary, finials 21 and 23 are attached to the end of the device 15 for aesthetic purposes.

FIG. 2 shows the device 15 having closed the curtains 11 and 13, by bringing their leading edges 11a and 13a, respectively, close together.

FIG. 3 shows the device 15 without the curtain attached. The device 15 consists of a housing 31, which include a slot 33 along its length at the top. In the depicted embodiment, the housing 31 serves the function of a curtain rod. As such, curtain rings 17 can be slid along it. Protruding from the slots 33 are the curtain mover tabs 35 and 37 also referred to herein as curtain linkers. As will be explained below, these curtain mover tabs/curtain linkers are attached to the leading edges 11a, 13a of the curtains 17, so that as the tabs 35 and 37 move toward each other, the curtains are closed. As the tabs 35 and 37 move away from each other, the curtains are opened.

FIG. 4 depicts how the device 15 can be telescopically lengthened. As shown, a second part of the housing 32 has been extended out of the first part 31. The benefit of being able to adjust the length of the device comes in the fact that the widths of windows in homes and businesses vary. By making its length-adjustable, the device can be sold in one size and then adjusted to different window widths by the installer. Preferably, the device can nearly double in length, preferably by at least about 90%. As such, one device can be sold that can be installed on windows from 3.5 to 6.5 ft. wide. Another device can be sold for windows from 6.5 to 12 ft. wide.

FIGS. 5 and 6 are cross-sectional views of FIGS. 3 and 4 respectively. Taken together, these Figures show how the device can be telescoped to change its length. As noted above, the second part of the housing 32 slides out of the first part of the housing 31.

A first threaded shaft 51 is axially rotated by a motor 61. Preferably, the motor 61 includes a gear box to achieve the proper balance of torque and speed. Also, the motor and gear box and the speeds at which they run are preferably designed for quiet operation of the device.

As shown in FIG. 5, the first shaft 51 is long enough to extend substantially the length of the housing when the device 15 is in the shortest length. As shown in FIG. 6, the first shaft 51 is long enough to extend just past the midpoint of the housing when the device 15 has been telescoped to its longest length.

Preferably, the shaft 51/53 is machined from a metal, such as steel. Alternatively, the shaft may be molded from a sufficiently rigid polymer. The threads on the shafts may vary depending on the number of rods and curtains in the application. The rods may comprise multi-start threads or single start threads. The thread pitch, as measured between the threads, may be between 3 and 16 threads per inch. The threads may be full form threads or truncated threads, that is the tread crests may be modified according to the desired application.

A second threaded shaft 53 parallels the first shaft 51 and is journaled in the opposite end of the device 15 from the motor 61. The second threaded shaft 53 has the same or a different thread pitch as the first threaded shaft 51. Again, as shown in FIG. 5, the second shaft 53 is long enough to extend substantially the length of the housing when in the shortest length. Likewise, as shown in FIG. 6, the second shaft 53 is long enough to extend just past the midpoint of the housing when the device has been telescoped to its longest length.

For most applications, it is preferred that the thread pitch is the same on the first threaded shaft as that on the second threaded pitch. When the thread pitch is the same, the first and second curtains are drawn towards each other and apart from each other at the same rate. Nevertheless in the atypical situation, for example, where the curtains do not meet at the center of the window, it may be desirable to use different thread pitches, whereby the first and second curtains are moved at different rates.

A first threaded nut 57 is moved laterally by rotation of the first shaft 51. Protruding from the top of the threaded nut 57 is the curtain mover tab or curtain linker 37. A second threaded nut 55 is moved laterally by rotation of the second shaft 53. The curtain mover tab 35 or curtain linker protrudes from the top of the threaded nut 55. The curtain mover tabs or curtain linkers 35 and 37 extend through the slot in the top of the housing part 31 and 32.

At the midpoint of the device, is a shaft gear body 59. As better depicted in FIGS. 7-10, This gear body 59 contains a first gear 81 that rotates with the first shaft 51. The gear body 59 also contains a second gear 83 that rotates with the second shaft 53. These first and second gears are the same size with the same number of teeth and are held in position to intermesh. As a result, when the first shaft 51 and first gear 81 rotate in one direction, the second gear 83 and second shaft 53 are made to rotate in the opposite direction. This means that, when the motor 61 rotates the first shaft 51 clockwise, the second shaft 53 is rotated counterclockwise. Consequently, as the motor rotates the first shaft in one direction, the threaded nuts 55 and 57 are moved toward each other, thereby closing the curtains. As the motor rotates the first shaft in the opposite direction, the threaded nuts are moved away from each other, thereby opening the curtains. Alternately, the first gear 81 and the second gear 83 may have more or less the number of teeth of the other gear. For example, gear 81 may have more teeth than gear 83 or vice versa. Consequently, the shafts 51 and 53 may rotate at varying speeds as may be desirable for opening and closing the curtains.

As best seen in FIG. 9, the first threaded shaft 51 is made with a longitudinal slot or channel 91 running at least partially along its length. As shown in FIG. 9, the slot 91 runs parallel to the longitudinal axis of the shaft 51. The slot 91 may not run parallel to the longitudinal axis of the shaft 51. For example, the slot 91 may run in a helix or spiral fashion along at least a portion of the outer surface of the shaft 51. Additionally, the slot 91 may not run the full length of the shaft to achieve a desired opening of the curtain. Also, as best seen in conjunction with FIG. 10, the first gear 81 includes an indexing tab or key 87 that slides within the channel 91, but fixes rotation of the first gear 81 with the first shaft 51. This design is advantageous for assembly of the device, as the gear 81 can be slid over the end of the shaft 51 and slid along the shaft 51 to the midpoint of the device. It is advantageous to be able to slide the gear to any point along the threaded shaft since the midpoint of the device will vary depending on the width of the window and the extent to which the device is telescoped to the optimum length of that width of window. Also, in the atypical situation where the curtains are not intended to close at the midpoint of the device, the gear can be slid to whatever point is intended to the be the closing point for the curtains.

In like manner, the second shaft 53 includes a longitudinal channel 93. A second gear 83 also includes an indexing tab or key 89 serving the same function as the indexing tab 87.

While the longitudinal channel and indexing tab are the preferred design, other means for fixing the gears at the appropriate point along the threaded shafts are available. For example, the gears can be slid along the shafts and then affixed with an adhesive. For another example, a set screw or spring loaded pin can be provided to lock the gears at the appropriate point.

The first gear 81 and second gear 83 are kept within the housing 71. For convenience in viewing the gears, only half of the housing 71 is shown in FIGS. 7-10. Preferably, the housing 71 is made of two halves and snap together to enclose the gears. The housing serves the purpose to maintain the gears in an intermeshed position.

In order to accommodate telescoping of the device, the first threaded nut 55 is configured so that the second threaded shaft 53 can extend past it, while the second threaded nut 57 is configured so that the first threaded shaft 51 can extend past it. One way to accomplish this is shown in FIG. 10, wherein the threaded nuts 55 and 57 each include two holes. In the threaded nut 55, the top hole 101, is threaded, so as to mate with the second threaded shaft 53, so that the threaded nut 55 is laterally moved by rotation of the second threaded shaft 53. The threaded nut 55 also includes a bottom hole 103 that is not threaded and is large enough to allow the first threaded shaft 51 to pass therethrough, in case the device is used in the shortened configuration and the first threaded shaft 51 overlaps with the second threaded shaft 53. In any event, the device is likely to be in the shortened configuration when shipped, so the nonthreaded hole 103 is needed.

Referring to FIG. 10, in like manner, the threaded nut 57 includes a top hole 105 that is not threaded, so that the second threaded shaft 53 can pass therethrough. The bottom hole 107 is threaded, so as to mate with the threads on the first threaded shaft 51, and so that the threaded nut 57 is moved laterally by rotation of the first threaded shaft 51.

In alternative embodiments, each of the threaded shafts are able to extend past the threaded nuts on the other threaded shaft by designing the threaded nuts so that they do not extend into the space that the threaded shaft passes through. In such embodiments, the threaded shafts may be aligned in the same horizontal plane, instead of the same vertical plane as depicted in the Figures.

Curtains are supported on curtain rods in various forms. FIGS. 1, 2 and 11 show a curtain that is supported by curtain rings. Referring to FIG. 11, the curtain rings 115 and 116 are looped through holes or eyelets at the top of the curtains. The ring 115 attached is to the leading edge 11a and 13a of the curtain, i.e., the edge that meets the other curtain in the pair when the curtains are closed. The remaining rings 116 are made to slide along the slot 33 along the top of the device 117. Ring 115 is captured in the groove 113a of connector 113, that is in turn connected to the protruding tab 111 attached to a threaded nut within the device. It is preferred that the means for capturing the curtain ring is simple to use and does not detract from the aesthetics of the curtains.

Curtains may also be supported on a curtain rod by curtain hooks, which are well-known in the art. FIG. 12 depicts a curtain supported by curtain hooks. In this embodiment, the curtain hook 125 at the leading edge of the curtain is captured in a simple pin 123, formed in the protruding tab 121 attached to a threaded nut within the device. The remaining hooks 126 may slide along the groove in the top of the device 127.

As shown in FIG. 13, curtains may also be supported by passing the curtain rod 137 through a pocket or hem 135a at or near the top of the curtain 135. In this embodiment, a spring-biased clip 133 is included on the protruding tab 131. The clip 133 is used to grab and retain an edge of the curtain and thus pull it back or push it closed as the threaded road is moved by rotation of the threaded shaft inside the device.

Preferably, the device is sold with a set of curtain connectors included that can be used with rings, hooks and pocketed curtains.

FIG. 14 depicts a double curtain system. As is often done in a high-end system, a pair of sheer curtains 143 is hung next to the window. The sheer curtains can be closed for privacy, while allowing light to pass into the room. A pair of heavier curtains 141 is hung parallel to the sheer curtains and closed when it is desired to block the light. In this depicted embodiment, the brackets 149 support two devices 145 and 149, both of which are constructed as described above. In other words, the sheers 143 are mounted on and opened and closed by device 147, while the heavier curtains 141 are mounted on and opened and closed by device 145.

FIG. 15 depicts another double curtain system, with the difference being that both curtains 151 and 153 are supported by the same device 155. This device 155 is similar to the devices shown above, except that there are two slots 161 and 163 through which two tabs 159 and 157 protrude. Inside the device are a total of 4 threaded shafts and two sets of gears and two motors, all arranged so that the two sets of curtains can be opened and closed independently.

Although the mechanism of the invention can be controlled by wired switches in a conventional manner, FIG. 16 depicts the preferred embodiment, wherein the devices 145 and 147 are configured to be remotely controlled. This can be accomplished with a dedicated remote-control device. However, the preferred system uses an app running on a smartphone 169. In addition to simply opening and closing the curtains, the app can also be used to set a program, whereby the curtains are opened or closed according to a pre-set schedule. That schedule may be determined based on times of day, or also based on factors such as the time for sunrise or sunset.

In some embodiments, sensors 171 are provided that detect levels of sunshine at the window. Signals from those sensors are then used to automatically shut the curtains if the sun is too bright, and/or open the curtains to let more light in. The device may also work with temperature sensors 173, that detect the temperature in the room. Signals from the temperature sensors may be used to determine when to open the curtains, i.e., to warm the room with sunshine, or to close the curtains, if the room is too warm and can be cooled by blocking the sunshine. The device can also be programmed to make it look like a home is occupied when the homeowner is away, by opening and closing the curtains at appropriate times. Preferably, the devices can also be controlled by voice through a smart speaker, such as an Amazon Alexa™, Google Home™ or Apple HomePod™.

As shown in FIG. 16, the app can be used with a dual curtain setting. As such, the user is able to program when to close the sheers for privacy, while letting in light, as well as when to close the heavier drapes to block light as well.

Preferably, the app is also used to set the endpoints, that is, full open and full closed positions. In simplest form, the user can push a button on the screen when the curtains are in each of these positions. Preferably, the system is configured to automatically detect these points, for example by detecting an increased current draw by the motor when the shaft meet resistance at the full open and full closed positions.

In addition, the position of the curtains can be monitored, after an initial endpoint calibration, by equipping the motor and/or the shafts with encoders, such as magnetic encoders, that count the revolutions of the motor or the shaft and thereby determine the position of the leading edge of each curtain.

As shown in the depicted embodiments, and as found in most installations of curtains, the mechanism is configured to move two curtains that make up a pair of curtains and meet in the middle of the window. In alternative embodiments, such as in large commercial installations, multiple mechanisms may be used along a whole wall of windows to open and close multiple pairs of curtains.

The invention has been described with reference to various specific and preferred embodiments and techniques. Nevertheless, it is understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.

Claims

1. A device for automatically opening and closing a pair of curtains comprising:

a rod comprising a longitudinal hollow space and a midpoint where a leading edge of a first curtain of the pair of curtains and a leading edge of a second curtain of the pair of curtains meet when closed;

a first threaded shaft having a thread pitch and housed within the hollow space, the first threaded shaft extending from a point near one end of the curtain rod to a first point past the midpoint;

a second threaded shaft having the same or different thread pitch as the first threaded shaft and housed within the hollow space, the second threaded shaft extending from a point near an opposite end of the curtain rod to a second point past the midpoint;

a first gear attached to the first threaded shaft and configured to rotate axially with the first threaded shaft;

a second gear attached to the second threaded shaft and configured to rotate axially with the second threaded shaft, and wherein the first and second gear intermesh, whereby, when the first threaded shaft rotates in a first angular direction, the second threaded shaft rotates in an opposite second angular direction;

a first threaded nut, threaded onto the first threaded shaft and configured to translate in a first direction toward the midpoint as the first threaded shaft is rotated in the first angular direction and to translate in an opposite second direction away from the midpoint as the first threaded shaft is rotated in the second angular direction;

a second threaded nut, threaded onto the second threaded shaft and configured to translate in the first direction as the second threaded shaft is rotated in the first angular direction and to translate in the opposite second direction as the second threaded shaft is rotated in the second angular direction;

a first curtain linker attached to the first threaded nut and attached near the leading edge of the first curtain;

a second curtain linker attached to the second threaded nut and attached near the leading edge of the second curtain;

a motor configured to rotate the first threaded shaft in the first angular direction and simultaneously rotate the second the shaft in the opposite second angular direction;

whereby, the device operates to close the pair of curtains when the first threaded shaft is rotated in the first angular direction and to open the pair of curtains when the first threaded shaft is rotated in the opposite second angular direction.

2. The device of claim 1, wherein the rod is a curtain rod, configured to support the pair of curtains.

3. The device of claim 1, wherein the motor is disposed in the hollow space near the first end of the curtain rod.

4. The device of claim 3, wherein the motor is linked to the first threaded shaft through a gear box.

5. The device of claim 1, wherein the midpoint is located at a center point of the device.

6. The device of claim 1, further comprising a controller configured to selectively activate the motor to rotate the first shaft in the first angular direction, and to activate the motor to rotate the first shaft in the second angular direction.

7. The device of claim 6, wherein the controller is further configured to receive instructions wirelessly.

8. The device of claim 7, wherein the controller is configured to receive instructions from a user's smart phone.

9. The device of claim 7, wherein the controller is configured to receive instructions from a cloud service.

10. The device of claim 7, configured to respond to voice commands to open or close the curtains.

11. The device of claim 7, wherein the controller is further configured to detect a first end point corresponding to the first and second curtain being fully closed and a second end point corresponding to the first and second curtain being fully opened.

12. The device of claim 1, further comprising a longitudinal slot in the rod, through which the first and second curtain linkers pass.

13. The device of claim 1, wherein the rod is longitudinally expandable by telescoping one portion of the rod within another portion of the rod, whereby the device can be adapted to span different widths.

14. The device of claim 13, wherein the first gear is configured to be attached at different points along the first threaded shaft, and wherein the second gear is configured to be attached at different points along the second threaded shaft, in order to accommodate different widths.

15. The device of claim 14, wherein the first gear is configured to be attached at any point along the first threaded shaft and wherein the second gear is configured to be attached at any point along the second threaded shaft, in order to accommodate infinite width adjustment between a greatest width and a shortest width.

16. The device of claim 14, wherein the first and second threaded shafts, each include a longitudinal channel and the first and second gears are indexed in the respective channel.

17. The device of claim 16, wherein the first gear is indexed by a first tab protruding from an inside diameter of the first gear into the longitudinal slots in the first threaded shaft, and wherein the second gear is indexed by a second tab protruding from an inside diameter of the second gear into the longitudinal slot in the second threaded shaft.

18. The device of claim 14, wherein the first threaded nut is configured to allow the second threaded shaft to extend beyond it and wherein the second threaded nut is configured to allow the first threaded shaft to extend beyond it.

19. The device of claim 14, wherein the first threaded nut has a first threaded hole that is threaded to mate with the first threaded shaft and a first nonthreaded hole with a diameter large enough to allow the second threaded shaft to freely pass therethrough, and wherein the second threaded nut has a second threaded hole that is threaded to mate with the second threaded rod and a second nonthreaded hole with a diameter large enough to allow the first threaded shaft to freely pass therethrough.

20. The device of claim 18, wherein the device can be expanded from its shortest length to its longest length that is at least 90% longer than the shortest length.

21. The device of claim 1, configured to open and close a first and second pair of curtains, and further comprising:

a third threaded shaft having a thread pitch and housed within the hollow space, the third threaded shaft extending from a point near the one end of the curtain rod to a third point past the midpoint;

a fourth threaded shaft having the same or different thread pitch as the third threaded shaft and housed within the hollow space, the fourth threaded shaft extending from a point near the opposite end of the curtain rod to a fourth point past the midpoint;

a third gear attached to the third threaded shaft and configured to rotate axially with the third threaded shaft;

a fourth gear attached to the fourth threaded shaft and configured to rotate axially with the fourth threaded shaft, and wherein the third and fourth gear intermesh, whereby, when the third threaded shaft rotates in the first angular direction, the fourth threaded shaft rotates in the opposite second angular direction;

a third threaded nut, threaded onto the third threaded shaft and configured to translate in the first direction toward the midpoint as the third threaded shaft is rotated in the first angular direction and to translate in the opposite second direction away from the midpoint as the third threaded shaft is rotated in the second angular direction;

a fourth threaded nut, threaded onto the fourth threaded shaft and configured to translate in the first direction as the fourth threaded shaft is rotated in the first angular direction and to translate in the opposite second direction as the fourth threaded shaft is rotated in the second angular direction;

a third curtain linker attached to the fourth threaded nut and attached near the leading edge of the first curtain in the second pair of curtains;

a fourth curtain linker attached to the fourth threaded nut and attached near the leading edge of the second curtain in the second pair of curtains;

a second motor configured to rotate the third threaded shaft in the first angular direction and simultaneously rotate the fourth the shaft in the opposite second angular direction;

whereby, the device operates to close the first pair of curtains when the first threaded shaft is rotated by the motor in the first angular direction and to open the first pair of curtains when the first threaded shaft is rotated by the motor in the opposite second angular direction; and

whereby, the device operates to close the second pair of curtains when the third threaded shaft is rotated by the second motor in the first angular direction and to open the second pair of curtains when the first threaded shaft is rotated by the second motor in the opposite second angular direction.

22. The device of claim 21, wherein the rod comprises a first slot, through which the first and second curtain linker pass, and a second slot, through which the third and fourth curtain linker pass.