Field of the invention

The invention relates to a roof ventilation system for a greenhouse or a warehouse, an assembly of a connector member and a bracket and to a greenhouse comprising such a roof ventilation system.

Background of the invention

In greenhouses, the gabled roofs can be opened by hinging open one or more windows that consist of glass panes, along a rail that extends at or near the ridge of the greenhouse.

In greenhouses that comprise a covering material other than glass such a ventilation system is less suitable. For instance, in areas that are subject to earthquakes, other roof and wall panels are used instead of glass. In particular if the roof comprises a transparent foil, providing separate windows for tensioning of the foil results in a heavy construction that blocks a relatively large amount of sunlight.

In semi-closed greenhouses, outside air is taken into the greenhouse and is mixed with air that is recirculated from an internal growing section, in an air treatment chamber or cabinet. The mixed and conditioned air is blown back into the growing section. Semi-closed greenhouses operate at an overpressure compared to ambient and have relatively small sized ventilation openings for letting air escape. When constructing semi-closed greenhouses, it is relatively difficult to exactly match the tolerances of the construction, whereas in traditional greenhouses the use of separate glass window panes of fixed dimensions allows for a continuous check on the tolerances. There is therefore a need, in particular in relation to semi-closed greenhouses, for a roof construction that is rigid and that allows accurate placement and interconnection of the assembling parts, thus avoiding undue strain on the panels.

For the ventilation of a greenhouses having a covering other than glass windows, it should be avoided that the opening and closing of the ventilation structure results in too much strain on the covering, which could cause the cover panes or sheets to rupture or otherwise be damaged. The same problem can occur when the greenhouse is covered by rigid panes that may be wholly or partly opaque, such as solar panels.

It is therefore an object of the invention to provide for a roof ventilation system in which the opening and closing avoids mechanical stress being exerted on the covering of the greenhouse.

It is also an object of the invention to provide a simple and reliable roof ventilation system in which the airflow from and to ambient can be accurately controlled, in particular when used in combination with semi-closed greenhouses. Summary of the invention

Hereto a roof ventilation system according to the invention comprises two support members on respective longitudinal sides along a ridge of a roof, a transverse support carrying a bracket extending vertically upwards from the transverse support, a hinging arm that is with a first end connected to the bracket and with a second end to an actuating rod that extends in the length direction, the hinging arm comprising a displacement section and a driving section, the displacement section having a longitudinal part that is with one end hingeably connected to the bracket and that with an actuating end is connected to a transverse part, the transverse part being with an end hingeably connected to the driving section, which driving section is with its second end hingeably connected to the actuating rod, wherein a top roof structure is connected to the actuating end and is raisable and lowerable by displacement of the actuating rod in the length direction.

The roof ventilation system according to the invention raises and lowers the top roof structure along a large length of the ridge to open or to seal a ventilation gap, while the roof panes remain stationary in the plane of the roof. The hinging arms that displace the top roof structure allow controlled and robust opening of the ventilation gap with a relatively small stroke, by horizontal movement of the actuating rod. The construction is light weight, is sufficiently flexible and allows opening of the roof by a single movement of the actuation rod, along a large part or along the whole length of the ridge resulting in a simple drive mechanism for the actuating rod.

The relatively small dimensions of the ventilation structure according to the invention, that extends substantially along the ridge and that has a relatively small width, results in reduced interception of light, and improved rigidity.

In an embodiment of a ventilation structure according to the invention, the bracket comprises two spaced-apart flanges with two rollers extending between the flanges and having their axes of rotation oriented mutually parallel, transversely to the length direction, in vertically spaced apart positions, the displacement member passing between the flanges and between the rollers.

In this way, the displacement member is slidingly fixed between the flanges in a reliable manner and can move back and forth in the length direction along the ridge for driving of the hinging arms that are connected to the displacement member.

The hinging arm may comprise two side members that are each attached to a respective flange of the bracket and that are mutually interconnected via a bridge part at their actuating ends. This provides a lightweight and stiff construction for support of the roof top part.

Another embodiment of a roof ventilation structure according to the invention a longitudinal seal extends along each support member, wherein the roof top structure comprises a V-shaped strip that is connected to the actuating end, which strip in a lowered position contacts the seal with its edges. The support members can for instance be made of extruded aluminium and provide on one side a lower support surface for the stationary roof panels, while along an edge that is situated closer to the ridge, the resilient material of the seal can be contacted by the V- shaped roof top part.

A greenhouse according to the invention comprises vertical columns with a roof having a ventilation structure, the columns supporting at least two support members extending in the length direction at a distance from the brackets, each support member comprising a longitudinal seal, a V-shaped strip connected to the actuating end and being in a lowered position with its edges engageable with the seal.

The roof ventilation structure according to the invention is light-weight and is of relatively small dimensions such that the shadow cast by the structure is small and the reduction in light yield in the growing space of the greenhouse is minimized.

Brief description of the drawings

An embodiment of a roof ventilation structure according to the invention will, by way of non-limiting example, be explained in detail with reference to the accompanying drawings. In the drawings:

Figs. 1 and 2 show a side view of a greenhouse comprising a roof ventilation structure according to the invention in respectively an open and a closed position,

Fig. 3 shows a partly cut-away perspective view of the roof ventilation structure of figs. 1 and 2,

Fig. 4 shows a side view of an embodiment of a roof ventilation structure according to the invention, in a closed position,

Fig. 5 shows a transverse cross-sectional view of the roof ventilation structure of fig. 4,

Fig. 6 shows a side view of an embodiment of a roof ventilation structure according to the invention, in an open position, and

Fig. 7 shows a transverse cross-sectional view of the roof ventilation structure of fig. 6.

Detailed description of the invention

Figure 1 shows a greenhouse 1 with a roof 2 and a roof ventilation structure 3 in the open position. The roof ventilation structure 3 comprises an actuating rod 5 extending in a length direction L, substantially along the length of the greenhouse 1. A number of spaced-apart curved profiles 7,8,9 ( indicated with reference sign 21 in figures 3-6), that extend from the gutters to the ridge (the gutters being supported by vertical columns), support the roof panels and brackets 11 that slidingly carry the actuating rod 5. The rod 5 is connected to hinge arms 12,13,14 that can move a cover strip 16 up and down when the actuating rod 5 is displaced in the length direction L.

In the upward position of the ridge covering strip 16 that is shown in figure 1, the actuating rod 5 is pushed to the left, and the strip 16 is lifted so that a gap 17 is formed between the lower edge 18 of the strip 16 and a support member 19. The embodiment of the greenhouse 1 shown in figure 1 is a semi-closed greenhouse with an air treatment unit 4 taking in outside air and mixes it with air that is recirculated from the growing section of the greenhouse 1. In the air treatment unit 4, that comprises heat exchangers and a fan, the internal and external air volumes are mixed, dehumidified, and brought at the desired temperature, and blown back into the greenhouse via a number of perforated ducts 6. The air that escapes along the length of the duct 6 is partly recirculated back to the air treatment unit 4 and is partly ventilated to the outside through the gap 17 of the roof ventilation structure 3, as indicated by the arrows V.

Figure 2 shows the greenhouse 1 with the ventilation structure 3 in the closed position. When the actuating rod 5 is moved to the right-hand side, a part of the hinge arms 12-14 comes to extend substantially parallel to the rod 5, such that the strip 16 is lowered in sealing engagement with the support member 19.

Figure 3 shows a perspective view of a part of the roof ventilation structure 3 with a transverse support 21 (indicated with reference signs 7-9 in figures 1 and 2) that is supported on the vertical columns of the greenhouse. The transverse support profile 21 carries a connector body 22 with a generally U-shaped cross section, having two parallel plates 23, 24 receiving the support profile 21 there between. The connector body 22 is provided with flanges 25, 26,26' on which the extruded support members 19, 20 are placed. The plate 24 of the connector body 22 supports at its upper edge 27 an upwardly projecting bracket 28. The bracket 28 has two side flanges 29, 30 that support two rollers 32, 33 of a resilient material. The rollers 32, 33 are rotatable about an axis 34, 35 and slidingly engage with the actuating rod 5.

The hinge arm 12 comprises a longitudinal part 36 and a transverse part 37. The longitudinal part 36 is connected with an end 44 to the axis 34. The transverse part 37 is connected to a driving section 38. The driving section 38 is connected to the actuating rod 5 in a hinge point 39. An actuating end 40, 40' of the longitudinal part 36 is attached to a connecting bracket 41 to which the ridge cover strip 42 is fixed. The ridge cover strip 42 is relatively narrow and can be of a simple and light weight construction.

The longitudinal support members 19, 20 on each side of the ridge 43 of the roof ventilation structure 3, support on one side 45, 45' roof panels 47, 47', which may be transparent or opaque and may comprise. On an upper side of the support members 19,20 a seal 48, 48' is situated against which the edges 51,51' of the ridge cover strip 42 are supported when the ventilation structure is in its closed position and the actuation rod 5 is pulled to the right- hand side, as is shown in the drawing.

As shown in figure 4, the sliding displacement of the actuating rod 5 along the rollers 32, 33, in the closing direction indicated by the arrow C, orients the diving section 38' of the hinge arm 12 in a downward direction, so that via the hinge connection 53, the transverse part 37' is pulled vertically downward and the longitudinal part 36' hinges in a clockwise direction around the axis 34 to be oriented substantially parallel to the actuating rod 5. This pulls the actuating end 40' of the longitudinal part 36' in a downward direction and clamps the edges 51, 51' of the cover strip 42 against the seals 48, 48', as shown in figure 5. As shown in figure 6, the displacement of the actuating rod 5 along the rollers 32, 33 in the opening direction indicated by the arrow O, orients the diving section 38' of the hinge arm 12 in a more horizontal direction, so that via the hinge connection 53, the transverse part 37 is rotated vertically upward and the longitudinal part 36' hinges around the axis 34, away from the actuating rod 5. This pushes the actuating end 40' of the longitudinal part 36' in an upward direction such that the edges 51, 51' of the ridge cover strip 42 are lifted away from the seals 48, 48', as shown in figure 7. In figure 7 it is shown that the hinge arm 12 comprises two longitudinal parts 36, 36' that are interconnected via a bridge part 54.