EP-4735722-A1 - A SCREENING APPARATUS FOR SCREENING AN OPENING

Abstract

A screening apparatus (1), comprising a flexible guide unit (7) and a sliding bar (11): which is fixable to an edge of a screen cloth (5); which comprises a first (12) and a second end portion (13), opposite one another; which comprises a first guide channel (16) of a variable part of the first guide unit decoupled from the cloth; in which the first guide channel (16) comprises: a first guide portion (25) which is curved, which originates from the first end portion; a second guide portion (26) which is straight, which originates from the first guide portion, which extends towards the second end portion (13); a third guide portion (27), which is curved, which originates from the second guide portion (26), which is arranged in the second end portion; a fourth guide portion (28), which is straight, which originates from the third guide portion (27), and which extends towards the first end portion (12); for slidably receiving and flexing the variable part of the first guide unit (7) during a first activation of the sliding bar (11) for reducing the screening to a minimum, forming the following sections of the guide unit: a first section (14), at least partially curved, in the first guide portion; a second straight section (15), in the second guide portion; a third curved section (72), in the third guide portion; and a fourth straight section (73) in the fourth guide portion.

Inventors

• Bruno, Giovanni

Assignees

• Dezain S.r.l.

Dates

Publication Date

20260506

Application Date

20240619

Claims (1)

1. CLAIMS 1. A screening apparatus (1) for screening an opening, which opening is rectangular and comprises a first side (3) which is vertical, wherein: - it comprises a frame; - it comprises a first housing (2) which is part of the frame and which is vertically positionable at the first side (3) of the opening; - it comprises a winding roller (4) which is housable vertically in the first housing (2) so as to rotate with respect to the axis thereof; - it comprises a screen cloth (5) which comprises: a first edge which is fixed to the winding roller (4) so that the screen cloth (5) can be wound on, and be unwound from, the winding roller (4); a second edge opposite the first edge; a third edge (6) which is interposed between the first edge and the second edge; - it comprises a first guide unit (7), preferably a guide chain, for inferiorly guiding the screen cloth (5), which first guide unit: is couplable to the third edge (6) of the screen cloth (5); extends in a longitudinal direction; which first guide unit comprises a first end (38), which is fixable to the frame in proximity of the lower part of the first side (3) of the opening or at the lower part of the first side (3) of the opening; comprises a second end (39) opposite the first end (38); and can flex along the extension thereof so as to form at least a straight section and at least a curved section; - it comprises a sliding bar (11) which: is fixable to the second edge of the screen cloth (5); comprises a first end portion (12) and a second end portion (13), which is opposite the first end portion (12); comprises a first guide channel (16) for guiding at least a variable part of the first guide unit (7) which is decoupled from the third edge (6) of the screen cloth (5); the first guide channel (16): originates at the first end portion (12) of the sliding bar (11), extends in the sliding bar (11) and comprises: a first guide portion (25), which originates at the first end portion (12) of the sliding bar (11) and which is at least partially curved; a second guide portion (26) which originates from the first guide portion (25) of the first guide channel (16), which is straight and which extends towards the second end portion (13) of the sliding bar (11); is characterised in that: the first guide channel (16) further comprises: a third guide portion (27), which originates from the second guide portion (26) of the first guide channel (16), which is arranged in the second end portion (13) of the sliding bar (11) and which is curved; a fourth guide portion (28), which originates from the third guide portion (27) of the first guide channel (16), which is straight and which extends towards the first end portion (12) of the sliding bar (11); the first guide channel (16) is configured for slidably receiving and flexing the variable part of the first guide unit (7) during a first activation of the sliding bar (11) along a screening plane (21) aimed at reducing the screening of the opening, in such a way that the second end (39) of the first guide unit (7) can slide in succession into the first guide portion (25) of the first guide channel (16), the second guide portion (26) of the first guide channel (16), the third guide portion (27) of the first guide channel (16) and the fourth guide portion (28) of the first guide channel (16). 2. The screening apparatus (1) of the preceding claim, further comprising a compensating unit (10), preferably a compensating chain or a compensating belt: which extends in a longitudinal direction; which comprises a first end (40), which is fixable to the frame in proximity of the upper part of the first side (3) of the opening or at the upper part of the first side (3) of the opening; which comprises a second end (41) opposite the first end (40); which can flex along the extension thereof to form: at least a straight section and at least a curved section; wherein the sliding bar (11) further comprises a second guide channel (17) for guiding at least a variable part of the compensating unit (10); wherein the second guide channel (17): originates at the second end portion (13) of the sliding bar (11), extends in the sliding bar (11) and comprises: a first guide portion (29), which originates at the second end portion (13) of the sliding bar (11) and which is at least partially curved; a second guide portion (30) which originates from the first guide portion (29) of the second guide channel (17), which is straight and which extends towards the first end portion (12) of the sliding bar (11); a third guide portion (31), which originates from the second guide portion (30) of the second guide channel (17), which is arranged in the first end portion (12) of the sliding bar (11) and which is curved; a fourth guide portion (32), which originates from the third guide portion (31) of the second guide channel (17), which is straight and which extends towards the second end portion (13) of the sliding bar (11); wherein the second guide channel (17) is configured for slidably receiving and flexing the variable part of the compensating unit (10, 24) during the first activation of the sliding bar (11) along a screening plane (21) aimed at reducing the screening of the opening, in such a way that the second end (41) of the compensating unit (10) can slide in succession into the first guide portion (29) of the second guide channel (17), the second guide portion (30) of the second guide channel (17), the third guide portion (31) of the second guide channel (17) and the fourth guide portion (32) of the second guide channel (17); wherein, when the first housing (2) is positioned vertically at the first side (3) of the opening with the winding roller (4) housed thereat and with the sliding bar (11) and which is vertical and which is fixed to the second edge of the screen cloth (5), the first guide channel (16) and the second guide channel (17) are entirely arranged on opposite sides with respect to a vertical plane (23) passing through the sliding bar (11) and parallel to the screening plane (21); wherein the screening apparatus (1) further comprises a synchronising unit for synchronising the sliding of the variable part of the first guide unit (7) in the first guide channel (16) and of the variable part of the compensating unit (10, 24) in the second guide channel (17); wherein the synchronising unit is connectable to the first guide unit (7) and to the compensating unit (10); and wherein the compensating unit (10, 24) and the synchronising unit are configured in such a way as, in use, to maintain the sliding bar (11) vertically orientated during a second activation of the sliding bar (11) along the screening plane (21) and aimed at increasing or reducing the screening of the opening. 3. The screening apparatus (1) of the preceding claim, wherein the synchronising unit comprises: - a first plurality of synchronising channels, in turn comprising: - a first synchronising channel (78): which is arranged in the first end portion (12) of the sliding bar (11) and which conjoins the second guide portion (26) of the first guide channel (16) and the fourth guide portion (28) of the first guide channel (16) to one another, - a second synchronising channel (79): which is arranged in the second end portion (13) of the sliding bar (11); which conjoins the second guide portion (30) of the second guide channel (17) and the fourth guide portion (32) of the second guide channel (17) to one another; - a third synchronising channel (80): which is arranged in the first end portion (12) of the sliding bar (11); and which conjoins the second guide portion (26) of the first guide channel (16) and the fourth guide portion (32) of the second guide channel (17) to one another; and - a fourth synchronising channel (81): which is arranged in the second end portion (13) of the sliding bar (11); and which conjoins the fourth guide portion (28) of the first guide channel (16) and the second guide portion (30) of the second guide channel (17) to one another; - a first cable (380): which is insertable in the first plurality of synchronising channels, in the first guide channel (16) and in the second guide channel (17); which can flex along the extension thereof to form at least a straight section and at least a curved section; which comprises a first end, which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which comprises a second end, which is opposite the first end of the first cable (380), which is fixed to the second end (41) of the compensating unit (10, 24) arranged in the second guide channel (17); - a second cable (381): which is insertable in the first plurality of synchronising channels, in the first guide channel (16) and in the second guide channel (17); which can flex along the extension thereof to form: at least a straight section and at least a curved section; which comprises a first end, which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which comprises a second end, which is opposite the first end of the second cable (381), which is fixed to the second end (41) of the compensating unit (10, 24) arranged in the second guide channel (17). 4. The screening apparatus (1) of the preceding claim, wherein the first cable (380), in a minimum screening configuration of the screening apparatus (1), comprises: - a first portion (82), which comprises the first end of the first cable (380); and which is arranged in the fourth guide portion (28) of the first guide channel (16); - a second portion (83): which originates from the first portion (82) of the first cable (380); and which is arranged in the first synchronising channel (78); - a third portion (84): which originates from the second portion (83) of the first cable (380); and which is arranged in the second guide portion (26) of the first guide channel (16) and in the third guide portion (27) of the first guide channel (16); - a fourth portion (85): which originates from the third portion (84) of the first cable (380); and which is arranged in the fourth synchronising channel (81); - a fifth portion (86): which originates from the fourth portion (84) of the first cable (380); which is arranged in the second guide portion (30) of the second guide channel (17), in the third guide portion (31) of the second guide channel (17) and in the fourth guide portion (32) of the second guide channel (17); and which comprises the second end of the first cable (380); and wherein the second cable (381), in the minimum screening configuration of the screening apparatus (1), comprises: - a first portion (87): which comprises the second end of the second cable (381); and which is arranged in the fourth guide portion (32) of the second guide channel (17); - a second portion (88): which originates from the first portion (87) of the second cable (381); and which is arranged in the second synchronising channel (79); - a third portion (89): which originates from the second portion (88) of the second cable (381); and which is arranged in the second guide portion (30) of the second guide channel (17) and in the third guide portion (31) of the second guide channel (17); - a fourth portion (90): which originates from the third portion (89) of the second cable (381); and which is arranged in the third synchronising channel (80); - a fifth portion (91): which originates from the fourth portion (90) of the second cable (381); which is arranged in the second guide portion (26) of the first guide channel (16), in the third guide portion (27) of the first guide channel (16) and in the fourth portion of the first guide channel (16); and which comprises the first end of the second cable (381). 5. The screening apparatus (1) of claim 2, wherein the synchronising unit comprises a second plurality of synchronising channels, in turn comprising: - a fifth synchronising channel: which is arranged in the first end portion (12) of the sliding bar (11) and which conjoins the second guide portion (26) of the first guide channel (16) and the fourth guide portion (28) of the first guide channel (16) to one another; - a sixth synchronising channel: which is arranged in the second end portion (13) of the sliding bar (11) and which conjoins the second guide portion (30) of the second guide channel (17) and the fourth guide portion (32) of the second guide channel (17) to one another; - a third cable (95): which is insertable in the second plurality of synchronising channels, in the first guide channel (16) and in the second guide channel (17); which can flex along the extension thereof to form at least a straight section and at least a curved section; which comprises a first end which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which comprises a second end, which is opposite the first end of the third cable (95) and fixed to the second end (41) of the compensating unit (10, 24) arranged in the second guide channel (17); - a first upper direction inversion element (94) which: which is arranged in the second end portion (13) of the sliding bar (11); which windingly receives the third cable (95); which js arranged and dimensioned in such a way that the third cable (95) can be arranged in the second guide portion (26) of the first guide channel (16), can wind about the first upper direction inversion element (94) and can be arranged in the second guide portion (30) of the second guide channel (17); - a fourth cable (96): which is insertable in the second plurality of synchronising channels, in the first guide channel (16) and in the second guide channel (17); which can flex along the extension thereof to form at least a straight section and at least a curved section; which comprises a first end which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which comprises a second end, which is opposite the first end of the fourth cable (96) and fixed to the second end (41) of the compensating unit (10, 24) arranged in the second guide channel (17); - a first lower direction inversion element (93) : which is arranged in the first end portion (12) of the sliding bar (11); which windingly receives the fourth cable (96); which is arranged and dimensioned in such a way that the fourth cable (96) can be arranged in the second guide portion (30) of the second guide channel (17), can wind about the first lower direction inversion element (93) and can be arranged in the second guide portion (26) of the first guide channel (16). 6. The screening apparatus (1) of the preceding claim, wherein the third cable (95), in a minimum screening configuration of the screening apparatus (1), comprises: - a first portion (97): which comprises the first end of the third cable (95); and which is arranged in the fourth guide portion (28) of the first guide channel (16); - a second portion (98): which originates from the first portion (97) of the third cable (95); and which is arranged in the fifth synchronising channel; - a third portion (99): which originates from the second portion (98) of the third cable (95); which is arranged in the second guide portion (26) of the first guide channel (16); - a fourth portion (201): which originates from the third portion (99) of the third cable (95); and which winds about the first upper direction inversion element (94); - a fifth portion (202): which originates from the fourth portion (201) of the third cable (95); which is arranged in the second guide portion (30) of the second guide channel (17), in the third guide portion (31) of the second guide channel (17) and in the fourth guide portion (32) of the second guide channel (17); and which comprises the second end of the third cable (95); and wherein the fourth cable (96), in the minimum screening configuration of the screening apparatus (1), comprises: - a first portion (203), which comprises the second end of the fourth cable (96); and which is arranged in the fourth guide portion (32) of the second guide channel (17); - a second portion (204): which originates from the first portion (203) of the fourth cable (96); and which is arranged in the sixth synchronising channel; - a third portion (205): which originates from the second portion (204) of the fourth cable (96); and which is arranged in the second guide portion (30) of the second guide channel (17); - a fourth portion (206): which originates from the third portion (205) of the fourth cable (96); and which winds about the first lower direction inversion element (93); - a fifth portion (207); which originates from the fourth portion (206) of the fourth cable (96); which is arranged in the second guide portion (26) of the first guide channel (16), in the third guide portion (27) of the first guide channel (16) and in the fourth guide portion (28) of the first guide channel (16); and which comprises the first end of the fourth cable (96). 7. The screening apparatus (1) of any one of claims 2-5, further comprising a second housing (42), which is part of the frame, and which is horizontally positionable at a second side (62) of the opening, which originates from the upper part of the first side (3) of the opening; wherein, in the second housing (42), when positioned horizontally, the following are contemporaneously housable: at least partially, the compensating unit (10), positioned horizontally; and the second end portion (13) of the sliding bar (11), with freedom to slide relatively between the second end portion (13) of the sliding bar (11 ) and the second housing (42). 8. The screening apparatus (1) of the preceding claim, comprising at least a first brush (48): which extends in a longitudinal direction; which is arranged horizontally in the second housing (42); which comprises bristles that are configured and arranged to inferiorly support the compensating unit (10, 24) housed in the second housing (42), wherein the at least a first brush (48) is arranged in one of following positions: on a first longitudinal side of the compensating unit (10, 24) housed in the second housing (42); on a second longitudinal side of the compensating unit (10, 24) housed in the second housing (42), which is opposite the first longitudinal side; or when the at least a first brush (48) is a pair of first brushes (48), on both the first and the second longitudinal side of the compensating unit (10). 9. The screening apparatus (1) of claim 1 , comprising a first partial compensating unit, in turn comprising: - a second lower direction inversion element (208) which is arranged in the first end portion (12) of the sliding bar (11); - a second upper direction inversion element (209) which is arranged in the second end portion (13) of the sliding bar (11 ); - a fifth cable (210): which has a first end which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which has a second end opposite the first end, and which is fixable to the frame in proximity of the upper part of a third side (61) of the opening opposite the first side (3) of the opening or which is fixable to the upper part of the third side (61) of the opening; and which is arranged in such a way that, starting from the relative second end, winds about the second upper direction inversion element (209), winds about the second lower direction inversion element (208) and enters the first guide channel (16). 10. The screening apparatus (1) of claim 1 or 9, comprising a second partial compensating unit, in turn comprising: - a third lower direction inversion element (213) arranged in the first end portion (12) in the sliding bar (11); - a third upper direction inversion element (214), arranged in the second end portion (13) of the sliding bar (11) above the a third lower direction inversion element (213); - a sixth cable (215): which has a first end which is fixed to the second end (39) of the first guide unit (7) arranged in the first guide channel (16); which has a second end opposite the first end, and which is fixable to the frame in proximity of the upper part of the first side (3) of the opening or which is fixable to the upper part of the first side (3) of the opening; and which is arranged in such a way that, starting from the relative second end, winds about the third upper direction inversion element (214), winds about the third lower direction inversion element (213) and enters the first guide channel (16). 11. The screening apparatus (1) of any one preceding claim, wherein the first guide unit (7) is a first guide chain (7) comprising a first plurality of guide chain elements, wherein each of the guide chain elements (221 , 248, 249, 250) of the first plurality of guide chain elements is hingeable at a first hinge axis (222) and at a second hinge axis (223), parallel to one another, and comprises: - a bottom (228) positionable resting on a horizontal support plane; wherein the first hinge axis (222) and the second hinge axis (223) are arranged at a first height from the support plane; - first engaging elements (226) for coupling to the third edge (6) of the screen cloth (5) and along a coupling direction which is perpendicular to the first hinge axis (222); wherein the first engaging elements (226) are arranged on an opposite side to the bottom (228) at a second height from the support plane which is lower than the first height; - a first longitudinal wall (224): arranged perpendicular to the bottom (228) and to the first hinge axis (222); which comprises a first portion (225) having a first thickness and a second portion (227) having a second thickness which is smaller than the first thickness, wherein the first portion (225) of the first longitudinal wall (224): it comprises: a first tapered projecting region (229), which has a first convex edge (230) and which projects with respect to a first side of the first engaging elements (226) which is parallel to the first hinge axis (222), which comprises a first chain element (331) arranged at the first hinge axis (222); and wherein the first portion (225) of the first longitudinal wall (224) further comprises a first concave edge (232) opposite the first convex edge (230) and complementarily profiled with respect to the first convex edge (230), wherein the second portion (227) of the first longitudinal wall (224) originates from the first concave edge (232) of the first portion (225) of the first longitudinal wall (224) and comprises a second chain element (240) arranged at the second hinge axis (223); - a second longitudinal wall (233) opposite the first longitudinal wall (224) which comprises: a first portion (234) having a third thickness; a second portion (235) having a fourth thickness which is smaller than the third thickness; a third portion (236) having the third thickness and a fourth portion (237) having the fourth thickness; wherein the first portion (234) of the second longitudinal wall (233) has a second tapered projecting region (238); which has a second convex edge (239); which projects with respect to the first side of the first engaging elements (226); which comprises a third chain element (241) arranged at the first hinge axis (222); and wherein the first portion (234) of the second longitudinal wall (233) further comprises a second concave edge (244) opposite the second convex edge (239) and complementarily profiled with respect to the second convex edge (239), wherein the second portion (235) of the second longitudinal wall (233) originates from the second concave edge (244) and comprises a fourth chain element (242) arranged at the second hinge axis (223); wherein the third portion (236) of the second longitudinal wall (233) is arranged inferiorly of the second portion (235) of the second longitudinal wall (233) and has a third tapered projecting region (245), which has a third convex edge (246), which projects with respect to a second side of the first engaging elements (226) opposite the first side of the first engaging elements (226); wherein the third portion (236) of the second longitudinal wall (233) further comprises a third concave edge (247) opposite the third convex edge (246) and complementarily profiled with respect to the third convex edge (246), wherein the fourth portion (237) of the second longitudinal wall (233) originates from the third concave edge (247) and is arranged inferiorly of the first portion (234) of the second longitudinal wall (233); wherein the first chain element (331) and the third chain element (241) of a first guide chain element (248) of the first plurality of guide chain elements are hinged, respectively, to the second chain element (240) and to the fourth chain element (242) of a second guide chain element (249) of the first plurality of guide chain elements which, in the first guide chain (7), follows the first guide chain element (248), and wherein the second chain element (240) and the fourth chain element (242) of the first guide chain element (248) are hinged, respectively, to the first chain element (331) and to the third chain element (241) of a third guide chain element (250) of the first plurality of guide chain elements which, in the first guide chain (7), precedes the first guide chain element (248) in the first guide chain (7), so that when the first guide chain (7) is flexed along the extension thereof forming a straight section and at least a curved section, in the straight section: the first convex edge (230) and the second convex edge (239) of the first guide chain element (248) contact, respectively, the first concave edge (232), and the second concave edge (244) of the second guide chain element (249) and the third convex edge (246) of the first guide chain element (248) contact the third concave edge (247) of the third guide chain element (250); while, in the curved section, the first convex edge (230) and the second convex edge (239) of a further first guide chain element (248) are separated, respectively from the first concave edge (232) and the second concave edge (244) of a further second guide chain element (249) of the first plurality of guide chain elements which, in the first guide chain (7), follows the further first guide chain element (248), and the third convex edge (246) of the first guide chain element (248) is separated from the third concave edge (247) of a further third guide chain element (250) of the first plurality of guide chain elements which, in the first guide chain (7), precedes the further first guide chain element (248). 12. The screening apparatus (1) of any one claim from 2 to 8 or claim 11 , wherein the compensating unit (10, 24) is a first compensating chain (10) comprising a plurality of compensating chain elements wherein each of the compensating chain elements (253, 262, 263, 264) of the plurality of compensating chain elements is hingeable to a third hinge axis (256) and a fourth hinge axis (257), parallel to one another, and comprises: - a body (258) comprising; a fifth chain element (255) passing through the third hinge axis (256); a first transversal side of the body (258) perpendicular to the third hinge axis (256); a second transversal side of the body (258) opposite the first transversal side of the body (258), - an undercut (259) accessible from the first transversal side of the body (258); and - a protuberance (265) which projects from the second transversal side of the body (258), which is housable in the undercut (259) of the body (258) of a further compensating chain element (253) of the plurality of compensating chain elements, and which comprises: a fourth convex edge (270); and a sixth chain element (271); wherein the fifth chain element (255) of a first compensating chain element (262) of the plurality of compensating chain elements is hinged to the sixth chain element (271) of a second compensating chain element (263) of the plurality of compensating chain elements which follows it in the first compensating chain, and the sixth chain element (271) of the first compensating chain element (262) is hinged to the fifth chain element (255) of a third compensating chain element (264) of the plurality of compensating chain elements which precedes it in the first compensating chain (10), so that when the first compensating chain (10) is flexed along the extension thereof forming a straight section and at least a curved section, in the straight section: the protuberance (265) of the first compensating chain element (262) is entirely housed in the undercut (259) of the body (258) of the third compensating chain element (264) with the first transversal side of the body (258) of the third compensating chain element (264) contacting the second transversal side of the body (258) of the first compensating chain element (262); and the protuberance (265) of the second compensating chain element (263) is entirely housed in the undercut (259) of the body (258) of the first compensating chain element (262), with the second transversal side of the body (258) of the second compensating chain element (263) contacting the first side of the body (258) of the first compensating chain element (262); and wherein in the curved section: - the protuberance (265) of a further second compensating chain element (263) of the plurality of compensating chain elements that follows, in the first compensating chain (10), a further first compensating chain element (262) of the plurality of compensating chain elements is partially housed in the undercut (259) of the body (258) of the further first compensating chain element (262) with the second side of the body (258) of the further second compensating chain element (263) being separated from the first transversal side of the body (258) of the further first compensating chain element (262); and - the protuberance (265) of the further first compensating chain element (262) of the plurality of compensating chain elements is partially housed in the undercut (259) of the body (258) of a further third compensating chain element (264) of the plurality of compensating chain elements which precedes it in the first compensating chain, with the first transversal side of the body (258) of the further third compensating chain element (264) being separated from the second transversal side of the body (258) of the further first compensating chain element (262). 13. The screening apparatus (1) of any one of claims 6-8 and 11-12, wherein the compensating unit (10, 24) is a second compensating chain (10) comprising a second plurality of compensating chain elements, wherein each of the compensating chain elements (253) of the second plurality of compensating chain elements is hingeable at a fifth hinge axis (256) and at a sixth hinge axis (257), parallel to one another, and comprises at least a first through-hole (280), which is parallel to the fifth hinge axis (256) which is accessible in a straight section of the second compensating chain; wherein the second housing (42) comprises at least a second brush (49): which extends in a longitudinal direction; which is arranged horizontally; which is arranged in the second housing (42) parallel to the screening plane (21); which comprises bristles which are configured and arranged to support the second compensating chain (10) by inserting in the first through-hole (280) of each of the compensating chain elements (253, 262, 263, 264) of the plurality of compensating chain elements of the second compensating chain (10) housed in the second housing (42), wherein the at least a second brush (49) is arranged in one of following positions: on the first side of the second compensating chain (10) housed in the second housing (42); on the second side of the second compensating chain (10) housed in the second housing (42) opposite the first side; or when the at least a second brush (49) is a pair of second brushes, on both the first and the second side of the second compensating chain (10) housed in the second housing (42). 14. The screening apparatus (1) of any one preceding claim, wherein: the screen cloth (5) comprises a fourth edge (8), opposite the third edge (6), wherein the screening apparatus (1) further comprises: - a second guide unit (37), for superiorly guiding the screen cloth, which second guide unit (37): is couplable to a fourth edge (8) of the screen cloth (5), which is opposite the third edge (6) of the screen cloth (5); extends in a longitudinal direction; comprises a first end; comprises a second end opposite the first end; is horizontally positionable at the second side (62) of the opening, laterally to the compensating unit (10), with the first end of the second guide unit (37) being fixed to the frame, in proximity of the upper part of the first side (3) of the opening or fixed at the upper part of the first side (3) of the opening, and with the second end of the second guide unit (37) being fixed to the frame, in proximity of the upper part of the third side (31) of the opening, in proximity of the upper part of the third side (61) of the opening or fixed to the upper part of the third side (61) of the opening; and - optionally, the second housing (42), wherein, in the second housing (42), when present and positioned horizontally, the second guide unit (37) is further contemporaneously housable, positioned horizontally and laterally to the compensating unit (10). 15. The screening apparatus (1) of any one preceding claim, wherein the first guide unit (7) comprises second engaging elements, arranged at the screening plane (21) and engageable to the third edge (6) of the screen cloth (5), wherein the second engaging elements comprise a first seat (43): which extends in a longitudinal direction; and which has a first access aperture (46), which extends in a longitudinal direction, which is positionable along the screening plane (21) and has a first width, measured perpendicularly to the screening plane (21); and wherein the third edge (6) of the screen cloth (5) is housable in the first seat (43) of the second engaging elements and comprises a first plurality of projecting retaining elements, wherein each projecting fixing element (44, 45) of the first plurality of projecting retaining elements has a fifth thickness, measured perpendicularly to the screening plane (21), that is greater than the first width so as to prevent the third edge (6) of the screen cloth (5) from exiting from the first seat (43) of the second engaging elements through the first access aperture (46) of the first seat (43) of the second engaging elements. 16. The screening apparatus (1) of any one of claims 14-15, wherein the second guide unit (37) comprises third engaging elements arranged at the screening plane (21) and engageable with the fourth edge (8) of the screen cloth (5), wherein the third engaging elements comprise a second seat (343): which extends in a longitudinal direction; and which has a second access aperture (346), which extends in a longitudinal direction, which is positionable along the screening plane (21) and has a second width, measured perpendicularly to the screening plane (21); and wherein the fourth edge (8) of the screen cloth (5) is housable in the second seat (343) of the third engaging elements and comprises a second plurality of projecting retaining elements, wherein each projecting fixing element (44, 45) of the second plurality of projecting retaining elements has a sixth thickness, measured perpendicularly to the screening plane (21), which is greater than the second width so as to prevent the fourth edge (8) of the screen cloth (5) from exiting from the second seat (343) of the third engaging elements through the second access aperture (346) from the second seat (343) of the third engaging elements. 17. The screening apparatus (1) of any one of claims 15-16, wherein each projecting fixing element (44, 45) of the first plurality of projecting retaining elements, and, when present, of the second plurality of the pluralities of projecting retaining elements is a tooth (45) of a zipper. 18. The screening apparatus (1) of the preceding claim, wherein the first guide unit (7) is a second guide chain comprising a second plurality of guide chain elements, wherein each of the guide chain elements of the second plurality of guide chain elements comprises: - a bottom wall (50); - a first external lateral wall (51) and a second external lateral wall (52), which originate from opposite sides of the bottom wall (50); - a first internal wall (53) and a second internal wall (54), which are arranged between the first external lateral wall (51) and the second external lateral wall (52), which originate from the bottom wall (50), and which are positionable parallel to the screening plane (21), which are separated from the first external lateral wall (51) and from the second external lateral wall (52); - a first retaining wall (55), which originates distally from the first internal wall (53), which is projecting from the first internal wall (53); and which is facing towards the second internal wall (54); and - a second retaining wall (56), which originates distally from the second internal wall (54); which is projecting from the second internal wall (54), and which is facing towards the first internal wall (53); wherein the first internal wall (53), the second internal wall (54), the first retaining wall (55) and the second retaining wall (56) together define a section of the first seat (43) of the second engaging elements (43) and wherein the first retaining wall (55) and the second retaining wall (56) together define a section of the first access aperture (46) of the first seat (43) of the second engaging elements (43). 19. The screening apparatus (1) of any one of claims 1-8 and 11-14, wherein the first guide unit (7) comprises fourth engaging elements, arranged at the screening plane (21) and engageable to the third edge (6) of the screen cloth (5) and wherein, when present, the second guide unit (37) comprises fifth engaging elements, arranged at the screening plane (21) and engageable to the fourth edge (8) of the screen cloth (5), wherein the fourth engaging elements, and, when present, the fifth engaging elements, comprise a pair of third brushes (47, 347) positionable substantially symmetrically, with respect to the screening plane (21), with the relative bristles being: facing towards the screening plane (21); terminating thereat; and wherein the screen cloth (5) comprises a fabric the weft of which is engageable with the bristles.

Description

A SCREENING APPARATUS FOR SCREENING AN OPENING DESCRIPTION OF THE INVENTION FIELD OF THE INVENTION The present invention relates to the technical sector of a screening apparatus of an opening, preferably made in a wall. The screening apparatus is of a horizontally sliding type and comprises a screen cloth that is rollable about a vertical axis. DESCRIPTION OF THE PRIOR ART With reference to the figures of the prior art 1 , 2, 8 and 9, a screening apparatus (100) is known for screening an opening, which opening is rectangular and comprises a first side (3) which is vertical. This screening apparatus has the following characteristics: - it comprises a frame; - it comprises a housing (102) which is part of the frame and which is vertically positionable at the first side (3) of the opening; - it comprises a winding roller (not illustrated in figures 1-9, relative to the prior art) which is housable vertically in the first housing (102) so as to rotate with respect to the axis thereof; - it comprises a screen cloth (105) which comprises: a first edge which is fixed to the winding roller so that the screen cloth (5) can be wound on, and be unwound from, the winding roller; a second edge opposite the first edge; a third edge (106) which is interposed between the first edge and the second edge; and a fourth edge (108) which is opposite the third edge (106); - it comprises a first guide unit (107) for inferiorly guiding the screen cloth (105); which is couplable to the third edge (106) of the screen cloth (105); which extends in a longitudinal direction; comprises a first end (138), which is fixable: to the frame in proximity of the lower part of the first side (3) of the opening or at the lower part of the first side (3) of the opening; which comprises a second end (139) opposite the first end (138); and can flex along the extension thereof so as to form: at least a straight section and at least a curved section; - it comprises a sliding bar (111) which: is fixable to the second edge of the screen cloth (105); comprises a first end portion (112) and a second end portion (113), which is opposite the first end portion (112); which comprises a first guide channel (116) for guiding at least a variable part of the first guide unit (107) which is decoupled from the third edge (106) of the cloth. The first guide channel (116) originates at the first end portion (112) of the sliding bar (111), extends in the sliding bar (111) and comprises: a first guide portion (125) (see figures 1 and 9), which originates at the first end portion (112) of the sliding bar (111) and which is at least partially curved; a second guide portion (126) which originates from the first guide portion (125) of the first guide channel (116), which is straight and which extends towards the second end portion (113) of the sliding bar (111). During a first activation of the sliding bar (111) along a screening plane (121) and aimed at reducing the screening of the opening to a minimum (see figure 8, in which the screening apparatus (100) is in the minimum screening configuration), there progressively form: a first section (114) of the first guide unit (107), which is at least partially curved, in the first guide portion (125) of the first guide channel (116); a second section (115) of the first guide unit (107), which is straight, in the second guide portion (126) of the first guide channel (116). Some known screening apparatuses (100) (see figures 3-7) can further comprise a compensating unit (110) which extends in a longitudinal direction; which comprises a first end portion (140) and a second and opposite end portion (141) (see figures 3 and 6). The first end (140) is fixable: to the frame in proximity of the upper part of the first side (3) of the opening; or at the upper part of the first side (3) of the opening. The compensating unit (110) can flex along the extension thereof to form at least a straight section and at least a curved section. In this case, the sliding bar (111) further comprises a second guide channel (117) for guiding at least a variable part of the compensating unit (110). The second guide channel (117) originates at the second end portion (113) of the sliding bar (111) and extends in the sliding bar (111). This is in order, at least partially, to slidably receive and flex the variable part of the compensating unit (110). During the first activation of the sliding bar (111), there is a progressive forming of a first section (174) of the first guide unit (110) which is at least partially curved and a second section (175) of the compensating unit (110), which originates from the first section of the compensating unit (110), which is straight and which comprises the second end (141) of the compensating unit (110). Further, the known screening apparatuses (100) generally also comprise a synchronising unit for synchronising the sliding of the variable part of the first guide unit (107) in the first guide channel (116) and of the va