Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This patent application claims the benefit of, under Title 35, United States Code, Section 119(e), U.S. Provisional Patent Application No. 60/778,909, filed Mar. 6, 2006. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to greenhouses, screenhouses and the like for use in farming or horticulture. More specifically, the present invention relates to a hybrid greenhouse combining features of greenhouses and screenhouses.  
       BACKGROUND OF THE INVENTION  
       [0003]     Conventional greenhouses are formed of rigid transparent panes, usually supported by a frame. They are generally used to shelter plants from inclement weather, while the air, soil and plants therein are warmed by incident solar radiation. Greenhouses generally allow control of the interior humidity, temperature, transmitted sunlight and wind. As some farmers and horticulturists find conventional greenhouses expensive, cheaper products have been developed in the industry of vegetable farming products, as well as for use in developing countries.  
         [0004]     Tents formed from netting such as mosquito nets, also called screenhouses, are also available. These screenhouses are widely used in warmer regions, such as South America and Mediterranean countries. However, screenhouses are known to expose plants to the elements and do not provide any control of the conditions inside the screenhouse. On the contrary, when the weather is milder, screenhouses let the plants be exposed to the natural outdoor weather, which can be very economical for the owners.  
         [0005]     Some modular greenhouses are available, for example, with opening roofs, such as in U.S. Pat. No. 6,978,573 (VAN DER HEIJDEN), which attempts to address the lack of flexibility of conventional greenhouses. However, such greenhouses are far more complex, and hence expensive, than the afore-mentioned screen houses.  
         [0006]     Also known in the art are greenhouses with tent-like coverings, for example, U.S. Pat. No. 4,416,928 (CARL) which disclose a cover structure covered by a plastic sheets which is shrunk and/or welded to a metal grid structure. Similarly, U.S. Pat. No. 3,375,831 (SERBUS) discloses a disposable tent-like covering comprising a disposable plastic sheet sandwiched between an inner and outer layer of perforate netting. U.S. Pat. No. 3,441,037 (TRANSEAU) discloses a portable cabana comprising a frame, a roof portion, removable exterior wall portions and a removable interior insect netting. In addition, U.S. Pat. No. 2,226,812 (GOLDBERG) discloses a plant protector for shielding a plant comprising a supporting frame, a wire-mesh dome and a translucent, waterproof hood covering the exterior of the dome.  
         [0007]     Thus, there remains a need for a hybrid greenhouse which combines at least some of the advantages of both conventional greenhouses and netted tents.  
         [0008]     Also known in the art are the following patents and published applications which also describe covered structures and the like: U.S. Pat. No. 3,869,827, U.S. Pat. No. 6,098,335, U.S. Pat. No. 6,192,643, U.S. Pat. No. 6,282,834, U.S. Pat. No. 6,758,014, U.S. Pat. No. 6,877,521, FR 2,598,881, US 2004/0049976, US 2004/0159346, US 2005/0072074, US 2005/0249917 and US 2006/0268544.  
       SUMMARY OF THE INVENTION  
       [0009]     It is an object of the present invention to fill some of the above-mentioned needs.  
         [0010]     It is also an object of the present invention to provide a hybrid greenhouse which provides the protection and control of conventional greenhouses on the one hand, and the inexpensiveness and permeability of the tents on the other hand.  
         [0011]     According to an aspect of the present invention, a hybrid greenhouse is provided comprising a base for installing the hybrid greenhouse on a surface, a space frame delimiting side faces and a top face for enclosing a space above the surface, at least one retractable transparent screen for at least partially shielding the space from the elements when extended, and a netting for preventing entry of insects into the space while allowing air to flow therethrough. The space frame is anchored to the base. The retractable transparent screen is retractably mounted to the space frame. The netting is mounted to the space frame for completely enclosing the space. The at least one retractable transparent screen is mounted between the removable netting and the space.  
         [0012]     Preferably, the at least one retractable transparent screen is extendable along at least a portion of the top face. Preferably, the side faces comprise a pair of opposing longitudinally extending end faces and a pair of opposing laterally extending gabled faces, the top face comprises at least one pair of sloping portions which extend longitudinally between the gabled faces, and the at least one retractable transparent screen comprises a pair of opposing retractable transparent screens which each extend along a respective one of the sloping portions.  
         [0013]     These and other aspects of the present invention will become more apparent upon reading the detailed description and upon referring to the following drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a perspective, partially cut-away view of the hybrid greenhouse according to a preferred embodiment of the invention shown.  
         [0015]      FIG. 2  is a side view of the hybrid greenhouse of  FIG. 1 .  
         [0016]      FIG. 3  is a typical cross-section of the hybrid greenhouse of the previous Figures.  
         [0017]      FIG. 4  is a cross-section of the hybrid greenhouse of the previous Figures taken at a gabled face.  
         [0018]      FIG. 5  is a detailed view of the area V of  FIG. 3 .  
         [0019]      FIG. 6  is a cross-section taken along VI of  FIG. 3 .  
         [0020]      FIG. 7  is a detailed view of the area VII of  FIG. 3 .  
         [0021]      FIG. 8  is a detailed view of the area VIII of  FIG. 4 .  
         [0022]      FIG. 9  is a detailed view of area IX of  FIG. 3 .  
         [0023]      FIG. 10  is a detailed view of area X of  FIG. 3 .  
         [0024]      FIG. 11  is a detailed view of area XI of  FIG. 3 .  
         [0025]      FIG. 12  is a detailed view of area XII of  FIG. 3 .  
         [0026]      FIG. 13  is a cross-section taken along XIII of  FIG. 3 .  
         [0027]      FIG. 14  is a cross-section taken along XIV of  FIG. 4 .  
         [0028]      FIG. 15  is a cross-section taken along XV of  FIG. 4 .  
         [0029]      FIG. 16  is a cross-section taken along XVI of  FIG. 4 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     While the invention will be described in conjunction with the exemplary embodiment, it will be understood that this are not intended to limit the scope of the invention to this embodiment. On the contrary, the invention is intended to cover all alternatives, modifications and equivalents as may be included as defined by the appended claims.  
         [0031]     In the following description, similar features in the drawings have been given similar reference numerals and in order to lighten the figures, some elements are not referred to in some figures if they were already identified in a precedent figure.  
         [0032]     Referring to  FIG. 1 , a hybrid greenhouse  10  according to a preferred embodiment of the invention is illustrated with several elements partially cut-away to increase clarity. The hybrid greenhouse comprises a rigid space frame  12  mounted on a base  14 , at least one retractable screen  16  and a netting  18 . The space frame  12  is preferably formed of circular or oval metal tubing, or indeed a combination of both. The base  14  is preferably formed of a plurality of concrete plugs set into the ground just below the surface upon which the hybrid greenhouse  10  is installed, although a solid concrete foundation or other form of foundation is also within the scope of the present invention.  
         [0033]     The space frame  12 , which is anchored to the base  14 , encloses a space above the surface within a set of side faces  20 ,  22  and  24  and a top face  26  delimited by the space frame  12 . The side faces  20  and  22  are preferably a pair of opposing faces which extend longitudinally. The side face  24  extends laterally and, for the sake of clarity, the corresponding side face which is opposite the side face  24  and completes the four side faces of the space frame  12  has not been shown. It will be apparent to one of ordinary skill in the art that this non-illustrated side face is simply a mirror-image of the side face  24 .  
         [0034]     The top face  26  is preferably formed by a series of longitudinally extending portions  28  sloping towards each other in pairs. These pairs of sloping portions  28  form a substantially triangular wave-like pattern of alternating peaks and valleys, which extend laterally across the hybrid greenhouse  10 , as is known in the art. The side face  24 , which extends from the ground to the edge of the sloping portions  28 , is therefore also called a gabled face  24  as its upper edge follows the alternating peaks and valleys of the top face  26 .  
         [0035]     The retractable screens  16  are retractably mounted to the space frame in order to at least partially shield the space contained within the space frame  12  from the elements when extended. Preferably, the retractable screens  16  are extendable along the sloping portions  28  such that, when extended, the screens  16  cover a substantial portion of the top face, thereby protecting the contents of the hybrid greenhouse  10  from heavy rain, hail, snow, and other natural events.  
         [0036]     As will be discussed in further detail below, the retractable screens  16  are preferably fixed to the sloping portions  28  along their upper, longitudinally extending edges at respective peaks of the top face  26 , and extended downwardly towards the valleys when so desired. Preferably, the screens  16  are impermeable UV-stabilized polyethylene sheets which are extended by rolling them up and down the sloping portions  28 . In use, the lower, free end of each roll-up polyethylene sheet  16  is rolled onto itself or a longitudinally extending cylinder as it is rolled up (retracted) or unrolled down (extended) along the sloping portions  28 . Preferably, the roll-up polyethylene sheet  16  is electromechanically controlled, that is a user may actuate the extension/retraction of the sheets  16  with an electrical switch or remote. For example, guided electric motors may be installed at either longitudinal extremity of the end-rolls  66  (see  FIG. 7 ) and used to roll and unroll the sheets  16 . Alternatively, the sheets  16  may be actuated manually or by purely mechanical mechanisms.  
         [0037]     As will be readily appreciated by one skilled in the art, the screens  16  are preferably provided along each of the sloping portions  28 . This is in contrast to the hybrid greenhouse  10  illustrated in  FIG. 1 , which has been partially cut-away for the sake of clarity.  
         [0038]     Similarly, the netting  18  preferably extends over the entirety of the side faces  20  and  22 , the gabled faces  28  and the top face  28  so as to completely enclose the space frame  12 . In this way, it is operable to protect the contents of the hybrid greenhouse  10  from entry of insects and other, large airborne nuisances. The netting  18  also permits air to flow through the hybrid greenhouse  10 , which can be advantageous in warm climates.  
         [0039]     The netting  18  is the outermost layer covering the hybrid greenhouse  10 . Advantageously, the netting  18  helps stabilize and retain the screens  16 , which could otherwise be blown away in high winds.  
         [0040]     Beneath each screen  16  is at least one end skirt  30  for guiding the screens  16  during extension and retraction. Preferably, a pair of end skirts  30  are fixed to the space frame  12  at either longitudinal end of each sloping portion  28  such that the longitudinal ends of the screens  16  are loosely sandwiched between the end skirts  30  and the netting  18 . The end skirts  30  are also preferably made of a transparent impermeable UV-stabilized polyethylene material.  
         [0041]     With reference to  FIG. 2 , the gabled face  24  of the hybrid greenhouse  10  of  FIG. 1  is shown. In addition to further illustrating the concrete plugs  14  into which the space frame  12  is mounted, a vent  32  is shown substantially at the peak of the top face  26 , as is commonly provided in the art. As is known in the art, and well within the scope of the present invention, vents  32  may alternatively, or additionally, be provided along one or more of the side faces  20 ,  22  and  24 .  
         [0042]      FIG. 3  shows a typical cross-section of the hybrid greenhouse  10 , while  FIG. 4  shows an equivalent cross-section directly before the gabled face  24 . This distinction will become more apparent upon description of the detailed views in  FIGS. 5 and 7 - 12  and the cross-sectional view in  FIGS. 6 and 13 - 16 . Additionally shown are wires  33  which are used as tension members within the space frame  12 , as is common in the art, and an extendable shade  35  which can be optionally extended horizontally across the hybrid greenhouse  10 .  
         [0043]     The detail illustrated in  FIG. 5  shows a vertical frame member  34  of the space frame  12 . The vertical frame member  24  is in the form of a circular tube and set into the concrete base  14 . The netting  18  is retained proximate the base of a longitudinal face, such as end faces  20  and  22  by a connector  36 . The connector  36  is preferably a combination of wirelock and wire-plast connectors, although other connecting means and combinations of connecting means, such as clips, snaps, bolts, screws, adhesives and staples are well within the scope of the invention. Each connector  36  preferably comprises a self-drilling screw  37  for fixing a wirelock  39  to the vertical member  34  and wire-plast  41  force-fit into the wirelock  39 .  
         [0044]     The connector  36  retains the netting  18  to a square tubing  38  which is bolted to the tube  34  and extends longitudinally across the space frame  12 . As such, the netting  18  is retained along the bottom edge of the hybrid greenhouse  10 . A free end  40  is illustrated hanging below the connector  36 .  
         [0045]     The cross-section illustrated in  FIG. 6  shows another connector  36  attached directly to the vertical tube  34 , with the square tube  38  shown extending longitudinally beneath it.  
         [0046]     With reference now to the details illustrated in  FIGS. 9 and 10 , the netting  18  is retained with connectors  36  at two more points an end face of the space frame  12 . In  FIG. 9 , the upper end  42  of the vertical tube  34  is joined to a longitudinally extending member  44 . The netting  18  is retained to member  44 , which is a substantially ovoid tube running parallel to the aforementioned square tube  38 , by a connector  36 . In  FIG. 10 , a connector  36  is used to retain the netting  18  to an extremity of a gutter  50 , which will be discussed in further detail with reference to  FIG. 7 .  
         [0047]     As will be appreciated from  FIG. 3 , between  FIGS. 10 and 11  is a first sloping portion  28   a.  In  FIG. 11 , a first roll-up polyethylene sheet  16   a  is shown fixed along its upper edge  46  by the same connector  36  which retains the netting  18  to a longitudinally extending ovoid tube  48 . As will be appreciated with by one of ordinary skill in the art, the upper edge  46  of the sheet  16   a  may be fixed to the space frame  12  in a variety of other ways without departing from the scope of the invention. For its part, the longitudinally extending tube  48  is mounted at the end of a sloping tube  52  which extends laterally and downwardly as a rafter would in a conventional sloping roof. The first sheet  16   a  is unrolled such that it extends towards the gutter  50  in  FIG. 10  along the laterally extending tube  52 . Below the tube  48  is the vent  32 . Consequently, while the netting  18  extends on both sides of the connector  36 , the sheet  16   a  does not.  
         [0048]     Continuing downward now to detail illustrated in  FIG. 12 , the uppermost edge of a second sloping portion  28   b  is shown. Similarly, a second roll-up polyethylene sheet  16   b  is fixed along its upper edge  54  by a connector  36  which also retains the netting  18  to a longitudinally extending ovoid tube  56 . The tube  56  is itself attached to another sloping tube  58 . The second sheet  16   b  is unrolled along the tube  58  which extends the length of the second sloping portion  28   b  towards a gutter shown in  FIG. 7 .  
         [0049]     The detail illustrated in  FIG. 7 , for its part, shows a gutter  50  which forms a valley in the top face  26  between the second sloping portion  28   b  and a third sloping portion  28   c.  The gutter  50  fixes the lower ends of two sloping tubes  58  and  60  to the rest of the space frame  12 . As is known in the art, the gutter  50  is also operable to collect run-off from the sloping portions. An insert  61  is positioned in the gutter  50  and comprises a raised portion  62  between a pair of recessed portions  64 . The recessed portions  64  of the gutter  50  are operable to receive the end-rolls  66  of roll-up polyethylene sheets  16   b  and  16   c  when fully extended. The raised portion  62  is provides a raised position on which to fix the netting  18 , via a connector  36 . The raised and recessed portions  62  and  64  are arranged such that the netting  18  does not interfere with the extension and retraction of the roll-up polyethylene sheets  16 . Preferably, each gutter  50  includes a number of the inserts  61  along its longitudinal length for retaining the netting  18 . Run-off is then collected in the gutter  50  below the insert  61  and does not interfere with the end-rolls  66  when fully extended.  
         [0050]     The detail illustrated in  FIG. 8  shows substantially the same cross-section as  FIG. 7  with the addition of a gutter plate  66  which is provided at the end of the gutter  50 .  
         [0051]     The cross-section illustrated in  FIG. 13  shows the sloping tube  58  of  FIGS. 7, 8  and  12  and a similar longitudinally spaced equivalent tube  68 , which also slopes transversally. In this case, these two tubes  58  and  68  delimit a longitudinal end of a sloping portion  28 . An end skirt  30  extends between the tubes  58  and  68  and is fixed on opposite sides by connectors  36 . Although not illustrated in this Figure, the roll-up polyethylene sheet  16   b  is disposed thereabove. In use, the sheet  16   b  is rolled and unrolled on this end skirt  30  and another end skirt  30  at its opposite longitudinal end.  
         [0052]     The cross-sections illustrated in  FIGS. 14 and 15  show the netting  18  fixed to tubing  70  and  58 , respectively, at the intersection of a sloping portion and a gable end, such as the longitudinally extending sloping portion  28   a  and the laterally extending gabled face  24 , by connectors  36 .  
         [0053]     Similar to  FIG. 5 , the cross-section illustrated in  FIG. 16  shows a vertical frame member  72  of the space frame  12  set into a concrete base  14  and restraining the netting  18  by a connector  36  along a laterally extending face, such as gabled face  24 .  
         [0054]     The tubing utilized in constructing the space frame  12  is preferably made of pre-galvanized steel with a minimum yield of 300 MPa, thus the expected life length of such structure is about  25  years in rural conditions. The moulded components of the structure are preferably made of extruded aluminium, for example 6063-T5, T54 or T6 grades. Multi-strands steel cables are suitable for the steel wires  33 , and it is recommended to use A325-type anti-galvanic-corrosion bolts which may be functional for over 1000 hours even in a saline mist. These technical specifications will be understood by a person skilled in the art and should not be considered as limiting the scope of the present invention.  
         [0055]     The hybrid greenhouse  10  disclosed herein allows the complete protection of plants from insects. The netting  18  further can also serve as a windbreaker in high winds.  
         [0056]     Moreover, the retractable screens  16  are operable to, inter alia, protect vulnerable plants such as tomatoes and cucumbers from heavy rains, which could otherwise damage the plants and consequently reduce their yield.  
         [0057]     In addition, it should be noted that a disadvantage of mesh fabrics such as mosquito nets, and other anti-insect nets of the like, is that they gather dust. In conventional hybrid products combining a netting layer and an impermeable sheet layer, the sheet layer is generally provided outside the netting layer. In contrast, the netting  18  of the hybrid greenhouse  10  is provided as the outermost layer and as such is washed by the rain.  
         [0058]     The above description of preferred embodiments of the present invention should not be read in a limitative manner as refinements and variations are possible without departing from the spirit of the invention. The scope of the invention is defined in the appended claim and its equivalents.

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