The invention relates to a (Dutch-type) greenhouse comprising a roof construction, at least one row of several support legs, which support at least part of the roof construction, and a cultivation gutter extending in the direction of said row inside the greenhouse and being supported by successive legs in the row.

It is noted that in practice the term "greenhouse" is generally understood to mean a hothouse suitable for cultivating vegetables, fruit or flowers and the like.

Such a greenhouse is generally known. Inside the greenhouse, cultivation gutters extending parallel to each other are provided, with an aisle being defined between neighbouring cultivation gutters.

A general drawback of a greenhouse of the type referred to in the introduction is that the aisles defined between neighbouring cultivation gutters inside the greenhouse are often not optimally dimensioned for cultivating activities. So far an adequate solution to this problem has not been found.

The object of the invention is to overcome the above drawback of the prior art, in particular to provide a greenhouse in which aisles between facing cultivation gutters are so dimensioned that both manual and automated cultivating activities can be optimally carried out. In order to accomplish that object, a greenhouse of the kind referred to in the introduction is according to the invention characterized in that the cultivation gutter has a central axis that extends in the longitudinal direction of the cultivation gutter, through successive support legs, and wherein furthermore an air hose extending in the direction of the row is provided, which air hose is designed for supplying air to the cultivation gutter, wherein the air hose has a central axis that extends in the longitudinal direction of the air hose, through the successive support legs. The air hose preferably forms part of an air distribution system, wherein air supplied by the system is supplied through the air hose to products being cultivated in the cultivation gutter. The air hose is to that end in particular provided with holes along its circumferential surface, through which air can be supplied to the cultivation gutter .

The greenhouse is preferably of the Venlo type.

It is noted that the greenhouse according to the invention also comprises at least one gutter section, from which gutter section the roof extends, wherein the gutter section is supported by the support legs, wherein the roof further comprise a ridge section as well as spaced-apart glazing bars which are connected to an edge of the gutter section near one end and to the ridge section near their other end, and wherein roof elements are provided between adjacent glazing bars, which roof elements are supported in rebates in the glazing bars and in a rebate in the gutter section.

In a preferred embodiment of a greenhouse according to the invention, the greenhouse comprises a roof construction, at least one row of several support legs, which support at least part of the roof construction, a cultivation gutter extending in the direction of the row inside the greenhouse and being supported by successive support legs in the row, wherein the support legs have two sides, seen in a direction transversely to the row, wherein at least part of the air hose extends within the sides of the successive support legs.

In another preferred embodiment of a greenhouse according to the invention, at least part of the air hose extends through at least one of the successive support legs.

In another preferred embodiment of a greenhouse according to the invention, the support legs are built up of at least two substantially vertical bars or rails, which are arranged some distance apart in a direction transversely to the direction of the row.

In another preferred embodiment of a greenhouse according to the invention, the support legs are built up of two substantially vertical bars or rails, which are arranged some distance apart in a direction transversely to the direction of the row and which lie substantially in the same plane. In another preferred embodiment of a greenhouse according to the invention, the bars or rails are fixed together by means of trusses. In particular, the air hose extends between the bars.

In another preferred embodiment of a greenhouse according to the invention, the greenhouse comprises support means for the cultivation gutter, which support means engage the support legs and which are adjustable for height relative to the support legs.

In another preferred embodiment of a greenhouse according to the invention, the air hose is a continuous hose which extends over several successive support legs. In particular, the air hose extends over substantially the entire length of the greenhouse. The invention also relates to a greenhouse comprising one or more of the aspects described in the appended description and/or shown in the appended drawings . The invention will now be explained in more detail with reference to figures illustrated in a drawing, in which:

- Figure 1 is a schematic, perspective view of a standard "Venlo-type" greenhouse; and

- Figure 2 shows a detail of figure 1, showing a preferred variant of the installation of a cultivation gutter and an air hose . Figure 1 shows a "Venlo-type" greenhouse comprising a supporting structure with vertical columns 2 and horizontal trusses 3 that connect the columns 2. The supporting structure supports a roof structure comprising roof gutters 4 and roof trusses 5 which extend toward a ridge 6. The roof structure and the supporting structure are provided with windows 7 for admitting daylight. At the top of the greenhouse 1, various driving devices may be provided, for example a driving device 8 for opening and closing the windows 7. Furthermore, a driving device (not shown) may be provided for operating a screen (not shown) mounted at the top of the greenhouse 1 for protecting crops being grown in the greenhouse 1 against fierce sunlight and reducing any heat losses via the roof structure as much as possible. The columns 2 are in turn connected to foundation piles 9, which project in part above the ground.

The "Venlo-type" greenhouse of figure 1 comprises cultivation gutters 10 (figure 2), each cultivation gutter 10 extending in the direction of a row of columns or support legs 2 and being supported by successive support legs 2 in the row. As shown in figure 2, each cultivation gutter 10 has a central axis extending in the longitudinal direction of the cultivation gutter 10, through the successive support legs 2 in the row. The cultivation gutter 10 is supported by a rectangular frame 11, which forms part of a respective support leg 2.

With reference to figure 2, the "Venlo-type" greenhouse of figure 1 is furthermore provided with air hoses 12, which each extend in the direction of a row of columns or support legs 2. The air hoses 12 are designed for supplying air to the cultivation gutter 10, each air hose 12 having a central axis that extends in the longitudinal direction of the air hose 12, through the successive support legs 2 of the row.

As shown, each air hose 12 is supported by a rectangular frame 13, which forms part of a respective support leg 2. The frame 13 is built up of two vertical bars or rails 14, which are arranged some distance apart, transversely to the direction of the row, and which lie in the same plane, and of two horizontal bars or rails 15, which are likewise arranged some distance apart, transversely to the direction of the row, and which likewise lie in the same plane. The air hoses 12 each have an open end and, opposite thereto, a closed end, which open end is connected to an air supply line (not shown) . The air supply line can draw in air from outside and supply it to the air hoses 12. According to another possibility, the air supply line draws in air from inside (in that case recirculation of air takes place) and leads it to the air hoses 12 again. Walls of the air hoses 12 are provided with perforations (not shown) , so that air supplied by the air supply line can exit the air hoses 12 in the direction of the cultivation gutters 10 via the perforations.

In order not to complicate figure 2 unnecessarily, only one row of columns or support legs 2 and only two columns or support legs 2 of the row are shown. Because of this, only one cultivation gutter 10 and one air hose 12 positioned thereunder are shown, therefore .