SCREEN DEVICE

Abstract

A screen device (1), comprising a screen roller (2), a screen (3) which can be rolled up and unrolled hereon, an end lath (4), which is fitted to an opposite side of the screen (3), and a tensioning system (8) to tension the screen (3) in the roll-up and unrolling direction, the tensioning system comprising on each lateral side of the screen (3) a band wheel (5) next to the screen roller (2), a tensioning cord (6), which can be rolled up and unrolled hereon and which, at its end away from the band wheel (5), is fastened to the end lath (4), away from the screen roller (2) a reversing wheel (7), via which the tensioning cord (6) is turned, and a spring sub-system (18), which comprises at least one spring element (9) for keeping the respective tensioning cord (6) under tension, wherein at least one of the spring sub-systems (18) comprises adjustors (10, 11, 14, 13, 16) for adjusting the spring force of the spring element (9).

Claims

1. A screen device, comprising a screen roller; a screen which can be rolled up and unrolled on this screen roller, an end lath, which is fitted to a side of the screen opposite to the side where the screen is rolled up and unrolled; a tensioning system to tension the screen in the roll-up and unrolling direction, comprising on each lateral side of the screen: i. a band wheel, which is arranged next to the screen roller; ii. a tensioning cord, which can be rolled up and unrolled on this band wheel; iii. on the side of the screen device away from the screen roller, a reversing wheel, via which the tensioning cord is turned; and comprising a spring system for keeping the tensioning cords under spring tension; wherein each tensioning cord, on its end away from the band wheel, is fastened to a respective end of the end lath, wherein the spring system comprises a first spring sub-system on a first lateral side of the screen, which first spring sub-system comprises at least one spring element for keeping the respective tensioning cord under tension, and a second spring sub-system, arranged separate from the first spring sub-system, on the second lateral side of the screen, which second spring sub-system comprises at least one spring element for keeping the respective tensioning cord under tension, wherein the first spring sub-system comprises adjustors for adjusting the spring force of the spring element, wherein each spring sub-system comprises a first pivot arm, which is articulately fastened to a first fixed pivot pin, which is fixedly arranged in the screen device and is articulately fastened to a displaceable pivot pin arranged displaceably in the screen device, wherein each spring sub-system comprises a second pivot arm, which is articulately fastened to the displaceable pivot pin and is articulately fastened to a second fixed pivot pin, which is fixedly arranged in the screen device, wherein the first pivot arm comprises a first part-arm and a second part-arm, which, with the aid of the spring element, are arranged resiliently with respect to each other, so that the spring force of the spring element drives the part-arms apart, and wherein around the displaceable pivot pin is fitted a guide wheel, via which the respective tensioning cord is turned.

2. The screen device according to claim 1, characterized in that the screen roller is an erected screen roller.

3. The screen device according to claim 1, characterized in that the second spring sub-system comprises adjustors for adjusting the spring force of the spring element.

4. The screen device according to claim 1, characterized in that around one of the fixed pivot pins is fitted a guide wheel, via which the respective tensioning cord is turned.

5. The screen device according to claim 4, characterized in that the guide wheel, which is fitted around one of the fixed pivot pins, is the respective reversing wheel.

6. The screen device according to claim 1, characterized in that the adjustors comprise a threaded rod, a holder, through which the threaded rod is rotatably fitted with its first end, a bracing element, through which the second end of the threaded rod or an extension piece of the threaded rod is fitted displaceably according to the longitudinal direction of the threaded rod, a nut, which comprises an internal screw thread corresponding with the external screw thread of the threaded rod and is fitted between the holder and the bracing element rotatably on the threaded rod, and a rotation-blocking element, which prevents absolute rotation of the nut in the screen device and leaves a relative rotation of the nut around the threaded rod unimpeded, so that the nut, upon rotation of the threaded rod in the screen device, moves over the threaded rod in the longitudinal direction of the threaded rod, and in that the spring element is fitted between the nut and the bracing element, so that the spring force of the spring element drives the nut and the bracing element apart.

7. The screen device according to claim 6, characterized in that the nut is provided on its outer periphery with a flat side, and in that the rotation-blocking element comprises a surface against which the nut is fitted with its flat side to prevent absolute rotation of the nut in the screen device.

8. The screen device according to claim 6, characterized in that the threaded rod forms part of the first part-arm of the first pivot arm, in that the holder is articulately fastened to the first fixed pivot pin in order to fasten this first part-arm articulately to this first fixed pivot pin, and in that the bracing element forms part of the second part-arm of the first pivot arm.

9. The screen device according to claim 1, characterized in that the screen device comprises on each lateral side a side guide for guiding the corresponding lateral side of the screen, and in that the tensioning system is arranged at least partially in these side guides.

10. The screen device according to claim 6, wherein the screen device comprises on each lateral side a side guide for guiding the corresponding lateral side of the screen, and in that the tensioning system is arranged at least partially in these side guides, wherein the rotation-blocking element is fixedly arranged in or forms part of the corresponding side guide.

11. The screen device according to claim 1, characterized in that the spring elements are realized as a helical spring.

12. The screen device according to claim 6, wherein the spring elements are realized as a helical spring and the helical spring is fitted around the threaded rod.

13. The screen device according to claim 12, characterized in that a cylindrical tube is fitted around the threaded rod, is fastened to the nut and is fitted displaceably through the bracing element as the said extension piece of the threaded rod, and in that the helical spring is fitted around the cylindrical tube.

Description

[0039] In this detailed description, reference is made by means of reference numerals to the hereto appended drawings, wherein in

[0040] FIG. 1 a screen device according to an embodiment of this invention is represented in front view, with cut-out side guides, in order to offer a view of the content of these side guides;

[0041] FIG. 2 the screen device from FIG. 1 is represented in front view, without the screen box, without the screen and without side guides;

[0042] FIG. 3 the bottommost cut-out side guide of the screen device from FIG. 1 is depicted in more detail;

[0043] FIG. 4 the spring sub-system from the bottommost side guide of the screen device from FIG. 1 is represented separately in front view, with the spring in the untensioned state;

[0044] FIG. 5 the spring sub-system from the bottommost side guide of the screen device from FIG. 1 is represented separately in front view, with the spring in the tensioned state;

[0045] FIG. 6 the spring sub-system from the bottommost side guide of the screen device from FIG. 1 is represented separately in perspective, with the spring in the untensioned state;

[0046] FIG. 7 the spring sub-system from the bottommost side guide of the screen device from FIG. 1 is represented separately in perspective, with the spring in the tensioned state.

DETAILED DESCRIPTION OF EMBODIMENTS

[0047] The depicted screen device (1) comprises a screen roller (2), which is accommodated in a screen box (32). In FIG. 1 the screen box is depicted, whilst in FIG. 2 the screen roller (2) is visible. This screen roller (2) is arranged vertically. A screen (3) is fastened with its one end to this screen roller (2) and at its other end to an end lath (4). By rotation of the screen roller (2), the screen (3) rolled onto and off this screen roller (2).

[0048] In the roll-up and unrolling of the screen (3), the lateral sides of the screen (3) and the end lath (4) are guided in side guides (17). For this purpose, a flexible thickening of the screen (3) is accommodated in a screen guide (31) housed in the side guide (17).

[0049] In order to keep the screen (3) tensioned in any position in the course of roll-up and unrolling, the screen device (1) comprises a tensioning system (8).

[0050] As can be seen in FIG. 2, the tensioning system (8) comprises on each lateral side of the screen (3): [0051] a band wheel (5), which is arranged next to the screen roller (2); [0052] a tensioning cord (6), which can be rolled up and unrolled on this band wheel (5) and which, at its end away from the band wheel (5), is fastened to a respective end of the end lath (4); [0053] on the side of the screen device (1) away from the screen roller (2), a reversing wheel (7), via which the tensioning cord (6) is turned; [0054] and a spring sub-system (18, 19), which comprises a helical spring (9) for keeping the respective tensioning cord (6) under tension and which comprises adjusting means (10, 11, 14, 13, 16) for adjusting the spring force of the helical spring (9).

[0055] The spring sub-systems (18, 19) function wholly independently of each other.

[0056] In FIGS. 3 to 7, the spring sub-system (19) which is accommodated in the bottommost side guide (17) of the screen device is represented in more detail. The spring sub-system (18) which is accommodated in the topmost side guide (17) of the screen device is constructed analogously.

[0057] The spring sub-system (19) depicted in FIGS. 3 to 7e comprises a first pivot arm (23), which is articulately fastened to a first fixed pivot pin (20) fixedly arranged in the screen device (1). This first pivot arm (23) is additionally articulately fastened to a displaceable pivot pin (21), which is displaceably arranged in the screen device (1). This spring sub-system (19) further comprises a second pivot arm (24), which is articulately fastened to the displaceable pivot pin (21) and is articulately fastened to a second fixed pivot pin (22), which is arranged in the screen device (1).

[0058] The first pivot arm (23) comprises a first part-arm (25) and a second part-arm (26), which, with the aid of the helical spring (9), are arranged resiliently with respect to each other, so that the spring force of this helical spring (9) drives the part-arms (25, 26) apart.

[0059] The first part-arm (25) comprises a threaded rod (10) having engaging means (30) for engaging on this threaded rod (10) with a hand tool for the rotation of this threaded rod (10). The first part-arm (25) further comprises a nut (13), which comprises an internal screw thread corresponding with the external screw thread of the threaded rod (10) and is rotatably fitted on the threaded rod (10). In addition, the first part-arm (25) further comprises a cylindrical tube (15), which is fastened to the nut (13) and extends substantially on the side away from the engaging means (30) around the threaded rod (10).

[0060] The threaded rod (10) is articulately fastened to the first fixed pivot pin (20) with the aid of a holder (11). For this purpose, this threaded rod (10) is fitted through an opening in this holder (11) and fixed with the aid of a locking screw (12). If the locking screw (12) is released, then the threaded rod (10) can rotate freely in this holder (11).

[0061] The nut (13) is of bar-shaped construction, with on its outer periphery four flat sides. The flat side of the nut (13), which is arranged at the rear in the figures, is fitted against the flat front side of a guide plate (16), so that the nut (13) cannot rotate in the screen device (1). The nut (13) is able to move with respect to this guide plate (16), so that relative rotation of the nut (13) about the threaded rod (10) is left unimpeded. Upon rotation of the threaded rod (10) in the screen device (1), the nut (13) moves over the threaded rod (10) in the longitudinal direction of the threaded rod (10). The nut (13) hereupon takes with it the cylindrical tube (15), so that the latter moves telescopically with respect to the threaded rod (10).

[0062] The second part-arm (26) is at its one end articulately fastened to the displaceable pivot pin (21). At its other end, this second part-arm (26) comprises a bracing element (14), through which the cylindrical tube (15) is fitted displaceably according to the longitudinal direction of the threaded rod (10), so that this cylindrical tube (15) is telescopically displaceable in a cavity (33) of this second part-arm (26).

[0063] The helical spring (9) is fitted around the cylindrical tube (15) between the nut (13) and the bracing element (14), so that the spring force of the helical spring (9) drives the nut (13) and the bracing element (14) apart, and thus drives the part-arms (25, 26) of the first pivot arm (23) apart.

[0064] The guide plate (16) is fixedly arranged in the side guide (17), as can be seen in FIG. 3. The said pivot pins (20, 21, 22) are fastened to the guide plate (16). A first guide wheel (27) is fitted around the displaceable pivot pin (21). The said reversing wheel (7) is fitted around the second fixed pivot pin (22). The tensioning cord is wrapped around this first guide wheel (27) and around this reversing wheel (7). An additional guide wheel (29) is further fastened to the guide plate (16) in order to guide the tensioning cord (6) away from the spring sub-system (19).

[0065] If, departing from the position as depicted in FIGS. 4 and 6, the locking screw (12) is released and the threaded rod (10) is rotated, so that the nut (13) advances into the position as depicted in FIGS. 5 and 7, then the cylindrical tube (15) will move jointly with the nut (13). Since the helical spring (9) pushes the bracing element (14) away from the nut (13), the second part-arm (26) will not move along proportionally, but only insofar as the counteracting forces of the tensioning cord (6) and the pivot arms (23, 24) allow this. The cylindrical tube (15) thus moves telescopically in the cavity (33) of the second part-arm (26). The helical spring (9) is hereupon tensioned.

[0066] In this way, the desired spring force of the helical spring (9) is adjusted. After this, the locking screw (12) is retightened.