Screen and assembly of a number of such screens

Abstract: A screen (A) comprising a number of tension rollers (1, 2, 3), each having its free ends movably bearing-mounted in two lateral guides (4, 5; 13) and each being rotatable around the longitudinal center line (L) of the relevant tension roller (1, 2, 3), each tension roller (1, 2, 3) comprising a tension spring (6), the tension rollers (1, 2, 3) being interconnected by screen cloth parts (7, 7b, 7d), and the tension springs (6) in the tension rollers (1, 2, 3) being biased such that the screen (A) tends to assume a rolled-in condition and is extendible against the bias of the tension springs (6).

Description: The invention relates to a screen according to the precharacterizing portion of claim 1. Such device is known from DE-A-3728913 and can be used for different applications such as, for instance, veranda awnings, sun tents, terrace coverings, insect barriers, swimming pool screens, windbreaks, sun filters, truck canvases, chamber screens, fast-travelling doors, greenhouses, container closures, dust guards for production processes, screens of carports, partition walls and the like. The known screen has the advantage that it can be manufactured in a simple and economical manner. Owing to the presence of the tension rollers, the screen cloth parts are always pulled taut. The tension rollers do not merely have a storage function for the screen cloth parts when the screen is in an entirely or partially rolled-in or slid-in condition, but also have the function of support section. For screens extending in a horizontal plane, the tension rollers may have a length of up to about 7 m, which hence provides the possibility of manufacturing a screen having a width of about 7 m and having only two lateral guides. The length of the screen is actually unlimited. The force required for further extending the screen substantially corresponds to the spring tension to be overcome in respect of the tension roller whose tension spring is slackest or least tautened. As a result of this principle, the screen can in each case be extended in a simple manner and with relatively little force. The screen can be rolled in very simply, as this is effected automatically by the biased tension springs when a locking, whereby the screen can be fixed in an entirely or partially extended position, is undone. Depending on the use of the screen, the screen cloth parts may be manufactured from cloth, canvas, foil, wire gauze or like material. A drawback of the known device is formed by the fact that each bearing block moving through the lateral guide is provided with one pair of wheels only, whose axes of rotation extend parallel to the longitudinal center line of the tension roller in question. When the tension rollers are wound up and unwound, the tension spring is tensioned and released. This does not only result in a tension in radial sense, but also in a tension build-up in axial sense. As a consequence, the shaft to which the tension spring is connected exerts a pressure or pulling force on the bearing block. Because of this pressure or pulling force, the bearing block will be pressed in a particular direction, causing the wheels to rub their lateral sides against the edges of the lateral guide, so that undue friction occurs. Because of these friction forces, winding up and unwinding the screen will require more force, which stands in the way of a proper operation of the known screen. Moreover, on account of an uneven distribution of forces on two bearing blocks of the same tension roller, wrinkle formation of the screen cloth parts connected thereto may occur when the tension roller is being wound up and/or unwound. Such wrinkle formation has a particularly adverse effect on the outward appearance of the screen. The object of the invention is to provide a screen of the type described in the opening paragraph without the above-mentioned drawbacks. To this end, the screen according to the invention comprises the features of claim 1. With the first pair of wheels, it is effected that the tension rollers can properly move through the main directions of the lateral guides. The at least one second pair of wheels or rollers whose axes of rotation extend perpendicularly to the imaginary plane in which the two lateral guides lie, take up the axially directed forces exerted on the bearing blocks by the shafts of the tension roller. Due to the presence of the at least one second pair of wheels or rollers, the wheels of the first pair are prevented from rubbing their lateral sides against the lateral guide and thus undergo an undesired friction. According to a further elaboration of the invention, it is preferred that each bearing block comprise two pairs of first wheels and two pairs of second wheels. Further elaborations of the invention are described in the subclaims and will hereinafter be further explained on the basis of a number of practical examples, with reference to the accompanying drawings. Fig. 1 is a perspective view of a first practical example of the screen according to the invention; Fig. 2 shows a free end of a tension roller of a known screen; Fig. 3 is a sectional view of a known screen having a single bearing wheel; Fig. 4 shows two side elevations of possible practical examples of a screen; Fig. 5 is a view in longitudinal section of a tension roller which can be used in a screen according to the invention; Fig. 6 is a perspective view of a second practical example according to the invention; Fig. 7 is a partial sectional view of an assembly of two screens having conventional bearing blocks; Fig. 8 shows two different manners in which the screen cloth parts can be wound up and unwound; Fig. 9 is a perspective sectional view of a portion of a screen, in which the bearing blocks are bearing-mounted in two directions; and Fig. 10 is a side elevational view of a bearing block of the screen shown in Fig. 9. All practical examples depicted show a screen A or parts thereof, comprising a number of tension rollers 1, 2, 3, each having its free ends 10 movably bearing-mounted in two lateral guides 4, 5 or 13. The tension rollers 1, 2, 3 are each rotatable around the longitudinal center line L. Each tension roller 1, 2, 3 comprises a tension spring 6 which is tensioned or released during rotation, depending on the direction of rotation of the tension roller 1, 2, 3. The tension rollers 1, 2, 3 are interconnected by screen cloth parts 7, 7b, 7d. The tension springs 6 in the tension rollers 1, 2, 3 are biased such that the screen A tends to assume a rolled-in condition. The screen A can be extended against the bias of the tension springs 6. The screen A shown comprises a starting tension roller 1, an end tension roller 2 and at least one intermediate tension roller 3. Attached to each intermediate tension roller 3 are two screen cloth parts 7, 7b, 7d, which, in a wholly or partially rolled-in condition, are wound one into the other, wholly or partially respectively. Preferably, the starting tension roller 1 comprises a first and a second starting roller screen cloth part 7a, 7b respectively. By an end thereof remote from the starting tension roller 1, the first starting roller screen cloth part 7a is fixedly connected to a fixed frame or construction part 8. The second starting roller screen cloth part 7b is connected, by an end thereof remote from the starting tension roller 1, to an intermediate tension roller 3. The end tension roller 2 comprises a first and a second end roller screen cloth part 7c and 7d respectively. At an end thereof remote from the end tension roller 2, the first end roller screen cloth part 7c comprises locking means 9 for securing the screen 1 in a wholly and/or partially unrolled condition. The second end roller screen cloth part 7d is connected, by an end thereof remote from the end tension roller 2, to an intermediate tension roller 3. As is shown clearly in Figs. 2, 3, 7 and 9, the free ends 10 of the tension rollers 1, 2, 3 are bearing-mounted in bearing blocks 11, which are movably bearing-mounted in the lateral guides 4, 5, 13. In the cases shown, the bearing blocks are formed by roller bearing blocks comprising rollers or wheels 16. The bearing blocks shown in Figs. 2, 3 and 7 are of the known type and have the drawbacks described in the introduction to the specification. Fig. 9 shows a practical example of a screen according to the invention. The end 10 shown in Fig. 2 corresponds to the left-hand end 10a of the tension roller of Fig. 5. The tension roller 1, 2, 3 comprises an internal shaft 18 which is rotatable relative to the tension roller sleeve 19. Also located in the interior of the tension roller 1, 2, 3 is a tension spring 6, having one end 6a thereof fixedly connected to the tension roller sleeve 19 and the other end 6b thereof fixedly connected to the internal shaft 18. When the screen A is being slid in and extended, the tension roller sleeve 19 of each tension roller 1, 2, 3 rotates relative to the internal shaft 18 located in that tension roller 1, 2, 3, so that the tension spring 6 located therein is released or tensioned respectively. The internal shaft 18 has its first end 10a provided with a non-round section, bearing-mounted in a non-round hole in the bearing part 17, so that rotation of the shaft 18 is prevented. As is already indicated hereinabove, the first end roller screen cloth part 7c is provided with locking means 9 at an end thereof remote from the end tension roller 2. In the practical example shown in Fig. 1, these locking means are designed as eyes 9 that can be hooked into a hook. Of course, other solutions are also conceivable. For instance, a friction engagement between the ends of the end lath 20 and the lateral guides is possible when the end lath 20, under the influence of the screen cloth tension, tilts around the longitudinal center line of the end lath 20. Fig. 6 shows an alternative embodiment of the locking means, where the locking means are formed by a drive motor 12 and a drive cord or chain 15 passed over guide wheels 16. At 21, the drive cord or the drive chain 15 has a first end thereof fixedly connected to the lateral guide 5. A second end of the drive cord or chain 15 is connected to the pulley 22 which is driven by the drive motor 12. With such construction, the screen can readily be slid in and extended. It is a matter of course that the motor 12 can also be replaced by a hand crank with a lock. Fig. 7 is a partial sectional view of an assembly of two screens A, A' in side-by-side arrangement. The adjacent free ends 10, 10' of the tension rollers 3, 3' of the two adjoining screens A, A' are bearing-mounted in a common lateral guide 13 and intercoupled via a common bearing block 11. The bearing block shown here is of the conventional type. It is a matter of course that bearing blocks according to the invention can be used here as well. It is thus effected that the screens A, A' of the assembly are extended and slid-in in the same manner and at the same time. Fig. 8 further shows that the screen cloth parts 7 of the screen A may follow different courses. The dotted line shows an embodiment where the screen cloth parts 7' in each case extend from the top side of one tension roller 3 to the bottom side of the next tension roller 3. The dashed line shows an embodiment where the screen cloth parts 7' successively extend from tension roller top side to tension roller top side and from tension roller bottom side to tension roller bottom side. Fig. 9 shows a portion of a screen in perspective cross section, where the screen comprises bearing blocks 11a, 11b which each have at least one first pair of wheels 30 whose axes of rotation 33 extend parallel to the longitudinal center line L of the relevant tension roller 1, and at least one second pair of wheels 31 whose axes of rotation 32 extend perpendicularly to an imaginary plane in which the two lateral guides 4, 5 lie. In the present practical example, each bearing block 11 comprises two pairs of first wheels 30 and two pairs of second wheels 31 spaced apart some distance on either side of an opening 34 in the bearing block part 17. In the opening 34, the free ends 10b and 10a of the tension roller 1 are accommodated. Because the bearing blocks 11 are guided in two mutually perpendicular directions in the relevant lateral guides 4 and 5 respectively, a particularly stable bearing is obtained. As is clearly visible in the present practical example, each free end of the tension roller 1 comprises a shaft end 10a, 10b. These shaft ends 10a, 10b are fixedly connected to the bearing blocks 11a, 11b associated therewith. The shaft ends 10a, 10b are mounted so as to be slidable in axial direction in the free ends of the tension roller 1. Accordingly, in spite of the very tight and accurate guidance of the bearing blocks 11a, 11b in the guides 4 and 5 respectively, the tension roller 1 has nevertheless some freedom of movement in axial direction. Due to this freedom of movement, wrinkle formation in the screen cloth parts is prevented. Fig. 10 is a side elevational view of a bearing block 11 of the screen shown in Fig. 9. For clarity's sake, no wheel or roller 30, 31 has been provided on the right-hand portion of the bearing block 11 in Fig. 10, so that the axes of rotation 33, 32 are clearly visible. It is readily understood that the screen cloth parts 7, 7a, 7b, 7c, 7d of the screen can be manufactured from cloth, canvas, foil, wire gauze or like material, depending on the application for which it is intended. It is clear that the invention is not limited to the practical examples described, but that various modifications are possible within the framework of the invention as defined by the claims.

Claims: A screen (A) comprising a number of tension rollers (1, 2, 3), each having its free ends movably bearing-mounted in two lateral guides (4, 5; 13) and each being rotatable around the longitudinal center line (L) of the relevant tension roller (1, 2, 3), each tension roller (1, 2, 3) comprising a tension spring (6), the tension rollers (1, 2, 3) being interconnected by screen cloth parts (7, 7b, 7d), and the tension springs (6) in the tension rollers (1, 2, 3) being biased such that the screen (A) tends to assume a rolled-in condition and is extendible against the bias of the tension springs (6), the free ends of the tension rollers being bearing-mounted in bearing blocks (11), comprising at least one first pair of wheels or rollers (30) whose axes of rotation (33) extend parallel to the longitudinal center line (L) of the relevant tension roller (1, 2, 3), by means of which the bearing blocks are traversable in the two lateral guides (4, 5; 13), characterized in that each bearing block (11) further comprises at least one second pair of wheels or rollers (31) whose axes of rotation (32) extend perpendicularly to an imaginary plane in which the two lateral guides (4, 5; 13) lie. A screen according to claim 1, characterized in that each bearing block (11) comprises two pairs of first wheels (30) and two pairs of second wheels (31). A screen according to claim 1 or 2, characterized in that each free end of the tension roller (1) comprises a shaft end (10a, 10b) which is fixedly connected to the bearing block (11a, 11b) associated therewith, the shaft ends (10a, 10b) being mounted in the free ends of the tension roller (1) so as to be slidable in axial direction. A screen according to claims 1-3, characterized by a starting tension roller (1), an end tension roller (2) and at least one intermediate tension roller (3), while to the or each intermediate tension roller (3), two screen cloth parts (7, 7b, 7d) are attached, which, in a wholly or partially rolled-in condition, are wound one into the other, wholly or partially respectively. A screen according to claim 4, characterized in that the starting tension roller (1) comprises a first and a second starting roller screen cloth part (7a and 7b respectively), while by an end thereof remote from the starting tension roller (1), the first starting roller screen cloth part (7a) is fixedly connected to a fixed frame or construction part (8), the second starting roller screen cloth part (7b) being connected, by an end thereof remote from the starting tension roller (1), to an intermediate tension roller (3), the end tension roller (2) comprising a first and a second end roller screen cloth part (7c and 7d respectively), while at an end thereof remote from the end tension roller (2), the first end roller screen cloth part (7c) comprises locking means (9) for securing the screen (A) in a wholly and/or partially unrolled condition, the second end roller screen cloth part (7d) being connected, by an end thereof remote from the end tension roller (2), to an intermediate tension roller (3). A screen according to any one of the preceding claims, characterized in that screen cloth parts (7, 7a, 7b, 7c, 7d) are manufactured from cloth, canvas, foil, wire gauze or like material. A screen according to any one of the preceding claims, characterized by a drive motor (12) and a drive cord or chain (15) for extending and pulling in the screen (A). An assembly of screens according to any one of the preceding claims, wherein at least two screens (A, A') are arranged side by side, the adjacent free ends (10) of the tension rollers (1, 2, 3) of two adjoining screens (A, A') being bearing-mounted in a common lateral guide (13) and intercoupled.

Inventors: VAN LOOSBROEK PATRICK FRANCISC, VAN LOOSBROEK, PATRICK FRANCISCUS JOHANNES
Applicants: VAN LOOSBROEK PATRICK FRANCISC, VAN LOOSBROEK, PATRICK FRANCISCUS JOHANNES
Application year: 1998
Main classification: E06B9
IPC codes: E06B9, E04F10