LOCKING DEVICE FOR CURTAINS, AWNINGS AND THE LIKE

Abstract: A locking device for curtains, awnings and the like, mounted to a hollow roller (31) assembly (30) on which, and from which, a curtain (32) is rolled up and unrolled, features a support (40) with a cavity (41) made therein. The support (40) can be integrally coupled with the roller (31) and inside its cavity (41) it accomodates coaxially and rotatably at least one substantially cylindrical locking element (50). The locking element (50) includes friction means (51) comprising a band of elastic material that elastically rubs on the support (40) so as to hinder its free rotation by friction action when the curtain (32) is not subjected to any external pull.

Description: 44563 LOCKING DEVICE FOR CURTAINS, AWNINGS AND THE LIKE BACKGROUND OP THE INVENTION The present invention concerns production of apparatuses, which are applied to windows or doors generally for dimming or protection, such as awnings or mosquito curtains rolling on and unrolling from a roller. In particular, the present invention refers to a device for locking these apparatuses in a desired position, usually open or close, but also m any intermediate position. DESCRIPTION OF THE PRIOR ART It is known that these apparatuses usually include a roller, on which the curtain (or net in case of mosquito curtain) rolls up, supported horizontally by suitable means inside a corresponding case, called rolling box, situated over the window or door, or anyway near its upper edge. The free extremity of the curtain goes out of the rolling box through a slit turned downwards. In this way, it is possible to unroll the curtain from the roller by pulling it downward. The curtain are then rolled again on the roller by elastic means, generally including a spring, situated inside the roller, and whose elastic constant is such that the curtain withdraws when released. Significant improvements to these means have been described in other patent applications, filed by the same Applicant. The curtain can also be operated by suitable control means, equipped with a pulley, integral with the roller and joined to a string. Two extremities of the string go out from the pulley, and therefore from the apparatus support, on its opposite ends, laterally and vertically with respect to the curtain. Downward pulling of one of the string ends provokes rotation of the roller in the re-rolling direction, while downward pulling of the other string end provokes its rotation in the curtain unrolling direction. Suitable locking means, usually joined with the roller, allow to position the curtain ap roximately in the desired point. Rotation resistance of these means must not be significant while the curtain is moving, both in rolling and unrolling directions, but must be sufficient to keep it in position when it is motionless, possibly overcoming the action of the above mentioned elastic means, which would tend to re-roll the curtain. An apparatus of the aforementioned type is disclosed in the Italian Patent no. 1.234.071, granted to the same Applicant. The locking means of the apparatus realised according to this patent allow to fix the curtain position in a quite simple and reliable way. The technical solutions described therein will be now briefly illustrated with reference to the figures 1 and 2 of the enclosed drawings, in which: - figure 1 is a section view of a head of the apparatus containing the locking means, and - figure 2 is a section view taken along the line II-II of figure 1. In these figures the roller, which accommodates a curtain (or a net or something else) rolled thereon, is indicated with numeral 1. One head of the roller 1, which is hollow, is closed by a cap 2 which is introduced inside the roller for a predetermined length. The two opposite heads of the cap 2 feature cavities 5, 6, respectively internal and external with respect to the roller 1. Near its bottom, the external cavity 6 is provided with an elevated edge defining a collar 7. In the central position of the wall 4, dividing the two cavities 5, 6, there is made a through hole 15. A substantially cylindrical support element 9, situated inside the external cavity 6, features a groove 10 made near its internal extremity and complementary to the collar 7, with which it engages. One end of a bar 14, aimed at e.g. supporting curtain rewinding elastic means, is fastened to the element 9, coaxially with the roller 1, as described in a more precise way in the aforementioned patent no. 1.234.071. The head of the support element 9, external with respect to the cavity 6, extends so as to define a tang 11, which allows to support the roller 1. Two squared surfaces 12a, 12b, are machined on the circumferential surface of the support element 9 and are situated in diametrically opposite positions in the part of the element 9 comprised between the roller 1 head and the collar 7. In the surface of the cavity 6, facing the squared surfaces 12a, 12b, there is made a recess 13, inside which a parallelepiped block 27 is introduced. The operation of the above described locking device appears evident from the figure 2. If the roller 1 rotates in the curtain unrolling direction S, nothing obstacles its rotation with respect to the motionless element 9, due to the fact that the squared surfaces, acting as inclined planes, push the block 27 inside the recess 13, each time the latter passes nearby. Rotation of the roller 1 in the opposite direction, the curtain rolling direction R, is generally prevented, since the block 27 remains in abutment against the two walls, square with each other, of the squared surfaces, which is in the upper position and the lower edge of the recess 13. Nevertheless, if the rotation of the roller 1 in the rolling direction R is rapid enough, the block 27 does not manage to leave the recess 13 and block the roller 1, due to combined effect of the block 27 inertia and the centrifugal force acting thereon. The above described solution, although rather efficient and simple to realise, presents a drawback deriving from the fact that it is practically impossible to make more than two squared surfaces 12a, 12b in the support element 9. This results in the fact that for each complete rotation of the roller 1, there are only two possible positions, in which it is blocked, and therefore also only two positions, in which the curtain can be blocked. This excludes a precise positioning of the curtain. This is not very important when the curtain must be fastened in a completely open or in an intermediate position, but it becomes so, when a closed position of the curtain is desired. In fact, this position usually does not coincide with one of the possible locking positions, therefore it is almost sure that there will be an air-hole below the lower edge of the curtain, which in case of a mosquito curtain cannot be acceptable. SUMMARY OF THE INVENTION The object of the present invention is to propose a device for locking awnings, curtains, and the like, that can guarantee their locking in any angular position of the roller, thus allowing complete closing. Another object of the present invention is to propose a locking device, which is also extremely simple, reliable and cheap to produce. The above mentioned objects are obtained by an assembly which includes a hollow roller, on which, and from which one curtain, such as window curtains, awnings and the like, is rolled up and unrolled, the assembly also including a device for locking the curtain in a desired position, comprising a support with a cavity made therein, integrally coupled with the roller ; inside its cavity, the support accommodates coaxially and rotatably at least one locking element which includes friction means which elastically rub on the support so as to hinder its free rotation by friction action of a predetermined entity, sufficient to prevent rotation thereof when the curtain is not subjected to any external pull action. BRIEF DESCRIPTION OF THE DRAWINGS The characteristic features of the invention will be pointed out in the following description, with particular reference to the enclosed drawings, in which: - figure 3 is a lateral section view of a roller carrying a curtain, provided with a locking device being the subject of the present invention; - figure 4 is a prospective view of the locking element of the aforementioned device; - figure 5 is a section view taken along the line V-V of figure 3; - figure 6 is a section view taken along the line VI-VI of figure 3. BEST MODE OF CARRYING OUT THE INVENTION With reference to the above mentioned figures, numeral 30 indicates an assembly for unrolling and rolling the curtain 32, partially illustrated in section relevant for the present description. This assembly includes a hollow roller 31, on which the curtain 32 is rolled up. This roller 31 is rotated, in known way, with respect to a shaft 33 coaxial therewith, either in the curtain 32 unrolling direction S or in the opposite direction R, in which the curtain 32 rolls up. The shaft 33 is supported, in known way, by a suitable spacer 34 situated at the front of the shaft 33 and near an extremity 31a of the roller 31. The opposite extremity of the shaft 33 is fastened, in known and not shown way, to a stationary structure, external with respect to the device 30 for rolling and unrolling the curtain 32. The locking device, being the subject of the present invention, is situated near this extremity 31a, externally with respect to the aforementioned spacer 34. It includes a support 40, substantially tubular, with a cavity 41 made therein. The external diameter of the support 40 is equal to the internal diameter of the roller 31, so that the support is snug fit into the extremity 31a of the roller 31 and fixed thereto due to interference. It can be removed from the roller 31 for e.g. maintenance operations. A ring 42, preferably made of material with low friction, featuring an external abutment surface 43, is fastened to the wall 41a of the cavity 41, in proximity of the external extremity 40a of the support 40. The support 40 supports rotatably, inside its cavity 41, a locking element 50, substantially of cylindrical shape and arranged coaxially within the support 40. In the region of its external extremity, this locking element 50 features a disc 52 having diameter bigger than the diameter of the body of the locking element 50 and such to perfectly enter a recess of the abutment surface 43 of the ring 42. A tang 53, made in the external face of the disc 52, is restrained in a stationary structure 60 so as to keep the locking element 50 immovable. The locking element 50 has a longitudinal groove 54 extending to the internal extremity of the locking element 50. The locking element 50 is also equipped with friction means, which rub elastically on the support 40 so as to hinder its free rotation by friction action of a predetermined effect, sufficient to impede this free rotation if the curtain 32 is not subjected to any external pull. The above mentioned friction means 51 are made of a band of elastic material, with an internal terminal portion 51a inserted in the groove 54 of the locking element 50 and rolled spiral-like thereon. This band is pre-loaded before the locking element 50 is introduced in the cavity 41. Due to the elastic reaction of the band 51, its external terminal portion 51b engages, with friction, the wall 41a of the cavity 41. Operation of the locking device will be now described, beginning from the condition in which the curtain 32 is completely rolled up on the roller 31. Generally, in this situation, the roller 31 is not subjected to any pull action which impose its rotation. Anyway, the elastic reaction of the band 51 acts on the support 40, increasing the position stability of the roller 31. When the curtain 32 is unrolled, a pull action is performed thereon which tends to impose a rotation to the roller 31 in the direction S. This makes the wall 41a of the cavity 41 slide on the external terminal portion 51b of the band 51, in the same direction as the band loading direction, and thus, its diameter reduction direction. Therefore, a weak friction is obtained on the curtain 32 movement, whose entity depends on the rigidity and elasticity of the band 51. If the action on the band 32 is interrupted, the elastic re-wind means would tend to roll it up again, overcoming the weight of this part of the curtain which is already unrolled and imposing to the roller 31 a rotation in direction R. In its turn, this rotation tends to make the wall 41a to slide on the external terminal portion 51b in a direction which tends to increase the diameter of the band 51, and thus its friction action on the wall 41a, up to an entity sufficient to overcome the action of the elastic re-wind means and therefore maintain the curtain 32 perfectly in the reached position. When it is necessary to roll up the curtain, an action is performed thereon, which tends to impose to the roller 31 a rotation in the direction R. This action sums up with the action of the elastic return means and allows to overcome the braking action of the band 51, thus allowing to roll the curtain 32 up again. If the rolling and unrolling device is of the previously described type, including a string acting on a pulley, the working principle of the locking device is substantially identical. In this case, however, the band 51 winds around the locking element 50 according to an opposite direction, so that the unrolling of the curtain 32 acts on the band 51 in the direction of its opening, and therefore of increase of its friction action. This allows the aforementioned band 51 to overcome the action of the weight of the part of the curtain 32 which is already unrolled, that would tend to continue its unrolling, while does not interfere in a considerable way with the rolling up of said curtain. The advantages of the present invention result first of all from the fact that the curtain 32 is locked immediately when an external pull is interrupted, in any position of the curtain. This allows its complete closing or its precise positioning in intermediate positions. Other advantages of the present invention derive from the fact that this locking device is extremely simple to produce, reliable and cheap. It is understood that the subject invention has been described, with reference to the enclosed drawings, as a mere, not limitative example, therefore possible variants resulting from practice and use are protected by the present invention as described above and claimed hereinafter.

Claims: CLAIMS 1. Locking device for curtains, awnings and the like, which is joined to an assembly (30) including a hollow roller (31), on which a curtain (32) is rolled up and from which the curtain is unrolled, said locking device being characterised in that it includes a support (40) with a cavity (41) made therein, which can be integrally coupled with the roller (31) and which, inside its cavity (41), accommodates coaxially and rotatably at least one locking element (50), equipped with friction means (51) which elastically rub on the support (40) so as to hinder its free rotation by friction action of a predetermined entity, sufficient to prevent free rotation if the curtain (32) is not subjected to any external pull action. 2. Device, according to claim 1, characterised in that said support (40) is substantially cylindrical and is removably mounted to an extremity (31a) of said roller (31) . 3. Device, according to claim 1, characterised in that said friction means (51) perform said friction action preferably according to the roller (31) rotation direction R, corresponding to the direction of the curtain (32) rolling up direction. 4. Device, according to claim 1 or 3, characterised in that said friction means (51) include at least one band of elastic material, wound spiral-like around said locking element (50) and having its internal terminal part (51a) fastened thereto and its external terminal part (51b) designed to engage with friction a corresponding cylindrical wall (41a) of said cavity (41) . 5. Device, according to claim 4, characterised in that said internal terminal part (51a) is introduced inside a longitudinal groove (54) made in said locking element (50) .

Inventors: BERGAMASCHI GIOVANNI, BERGAMASCHI, GIOVANNI
Applicants: BERGAMASCHI GIOVANNI, SUNPROJECT SRL, BERGAMASCHI, GIOVANNI, SUNPROJECT S.R.L.
Application year: 1997
Main classification: E06B9
IPC codes: E06B9