FORM - 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
TITLE OF INVENTION A Resilient Greenhouse Structure
APPLICANT
MAH1NDRA & MAH1NDRA LTD, a Company Registered under the Indian Companies Act, having office at 1913, having its Registered office at Gateway Building, Apollo Bunder, Mumbai - 400001 (Maharashtra).
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of the invention and the manner in which it is performed.

Field of the invention
The present invention relates to frame structured greenhouses with improved structural stability to sustain high wind loads, dead loads and the live loads.
Background and prior art
Greenhouses have been built to provide controlled environment with appropriate ventilation, temperature and humidity control to facilitate productive horticultural and agricultural practices. The present greenhouses in the market are heavy duty structures to attain structural stability. Such greenhouses therefore involve high construction costs.
US 3,028,872 discloses constructions having a body comprising a main framework covered with flexible transparent sheet material is provided with ventilating means comprising at least one ventilating panel having with resilient frame, one part of the frame being secured between adjacent portions of the main framework and so on that another of the frame, due to their natural resilience of the frame, tends to take up a position outwardly of the accurate shape of said adjacent portions thus providing a ventilating opening between said portions, and retaining means to control the position of the said other part and operable to bend the frame to said accurate shape to close the ventilating opening.
WO 2005/029941 discloses an inexpensive greenhouse vent which is achieved by using a bendable vent panel at the apex of a glazed greenhouse roof and fastening a central portion of the vent panel to a ridge at the apex and bending and bowing opposite sides of the vent panel upwardly or downwardly between the closed and open venting positions. The vent header, vent rail and vent panels are preassembled together on the ground and raised into position and attached to the greenhouse frame members.
WO 2005/029941 discloses greenhouses that vary from 20 feet to 40 feet in width. The roofs are usually supported by columns varying in height from 10 to 14 feet. The roof support usually comprises structural arches usually bent within about a 12 foot to 25 foot range of radius. These curved rafter supports are usually round tubes of about 1.5 to 3inches in diameter.
The conventional greenhouses and in particular structures suffer from the drawback as follows:
• Substantially high specific weight that is required to withstand wind forces
• Need of actuators with moving parts that required to be operated manually or electronically to adjust the ventilation in the greenhouse

• Limitation of the actuators to reduce the impact of high wind forces on the greenhouse structure
• Limitation of the greenhouse structure to withstand diverse loads such as wind load, live load and dead weight.
There is therefore a need to provide a greenhouse configuration of high specific strength to withstand diverse loads without compromising on ventilation, temperature, humidity and volume of air inside the greenhouse needed for plant growth.
Summary of the Invention
The main object of the invention is to provide a structurally stable greenhouse to withstand wind load, dead load, live loads and yet provide appropriately controlled ventilation, temperature, humidity and volume of air to facilitate plant growth.
Another object of the invention is to provide a greenhouse structure that sustains live loads, and wind load of at least 120 km/hr.
Yet another object of the invention is to provide structural truss geometry of members of selected cross-sections and thicknesses to withstand buckling, bending and torsion forces.
Yet another object of the invention is to provide greenhouse structure that provides ease, support, stability and the strength to the workmen during assembly and servicing operations.
Yet another object of the invention is to obviate welding for joining the green house structure members.
Yet another object of the invention is to provide optimised clamps as joining element made of pressed components to achieve substantially higher strength and life.
Yet another object of the invention is to provide structural options in the greenhouse structure to enable phase wise incremental extensions to the greenhouses and customise enhancement of the coverage area.
Yet another object of the invention is to select cross section of the member for high specific strength.
DETAILED DESCRIPTION OF THE INVENTION
Features and advantages of this invention will become apparent in the following detailed description and the preferred embodiments with reference to the accompanying drawings.

Figure 1 Schematic of the structure illustrating "M truss" configuration (Sheet 1)
Figure 2 Schematic of the structure illustrating "W truss" configuration (Sheet 2}
Figure 3 Schematic of the frame configuration (Sheet 3)
Figure 4 Schematic of the column and side support structure {Sheet 3)
Figure 5 Schematic of "SUN Truss" side support structure (Sheet 4)
Figure 6 Schematic of member sections (Sheet 4)
Figure 7 Schematic of Optimised Clamps (Sheet 5)
Figure 8 Schematic of Greenhouse structure of the present invention (Sheet 6)
Figure 9 Schematic of Greenhouse structure w/o present invention (Sheet 6)
The schematic of the greenhouse structure of the present invention is depicted in Figure 1 and Figure 2. The characterizing dimensions / proportions of the structure in terms of height, bay width, and roof height are indicated in these Figures. "H" is the total height and "W" is the bay width, ft is height of roof. It is possible to achieve the desired structural strength & stability by simultaneously optimising the angle "CD" between slope of the roof and bay width. The nodes are represented with a, b, c, d, e, f, g, h, I, j, k, 1 are the locations used as support to climb on the structure for the purpose of assembly, repair, or maintenance work.
In a preferred embodiment there are two configurations of the greenhouse structure characterized by the combination of elements in roof structure. The first configuration appears in the form of English letter M as indicated by a dotted red circle Figure 1.
The second configuration appears in the form of English letter W, as indicated by a dotted red circle in Figure 2. It comprises of principal curved members 30 and 31, a horizontal principal member 32. The said principal members are supported by other support members viz. (34, 35, 37, and 38) that are disposed diagonally to form nodes at the ends of the members joined with each other to form a truss as shown in Figure 2. These members are singularly and collectively join the said principal members and form "W" configuration.
One of the preferred configurations of the frame structure of the present invention is illustrated in Figure 3. It comprises of principal curved members 30 and 31, a vertical principal member 36 and a horizontal principal member 32. The said curved member 30 and 31 are curved and are fastened to each other with bracket. The member 30 extends as illustrated in the Figure 3 & 4 to form a ventilator. The extended portion of the member 30 is supported by other support members 40 and 41 as depicted in the Figure. The said principal members are supported by other support members viz. 33, 34, 35, 36, 37, 38, and 39 that are disposed vertically and diagonally to form nodes at the ends of the members joined with each other to form a truss as shown in the Figure. These members are singularly and collectively join the said principal members and form an "M" configuration.

It is to be noted that the unit created by any of the three members (30,31,32) in this truss is triangular. This enables appropriate force transfer from the truss members to the support. The diverse loads and the external force created due to this external load act at the said nodes. Every member of this truss is in pure compression or pure tension. The shear, bending moment, and other more complex stresses are all practically zero. This enables much larger load withstanding in pure compression or tension for a member than in shear, bending or torsion.
The desired structural strength & stability is achieved by simultaneously optimising the angle "O" (Refer Figure 1 and Figure 2) between slope of the roof and bay width, and further by adding the most appropriately designed Trusses of cross sections placed at the most appropriate position.
The synergistic configuration of the principal and support members is arrived at to cater to the maximum wind load and other loads. In such a configuration the angle made by the said principal curved member 30 with horizontal is in the range of 20 to 30 degrees with horizontal. The intersection and in turn joining of the said principal curved member 31 with the said member 30 is at the vertical distance (from the said principal member 32) that is in the range of 20 to 40% of the length of the said principal member 32. As illustrated in Figure 4, the greenhouse structure further comprises of columns 400 and inclined member 401. It may be noted that the roof truss frame configuration 300 and two columns form a module of the structure called "Sun Truss". Such Sun Trusses are repeated as per the strength requirement for wind load & expanse required for the greenhouse. The said inclined member 401 is in the form of a column bracing that is provided along with "Sun Truss" members 10, 20, 30, 40 together forming the SUN rays when fitted in bracket on column as depicted in Figure 5. This configuration obviates use of heavier member 401 required to resist the same wind forces & bending moment.
It is surprisingly found the highest structural strength and ability to withstand wind loads of 120 Km/hr is achieved for "h/w" ranging from 0.20 to 0.27, H/W between 0.71 to 0.85 and angle "0" between 22 to 27°.
In one of the embodiments the clamps are ribbed at selected locations to enable higher strength compared to the conventional press parts (of same weight). The said clamps as well strengthen the structure member on which it is mounted against buckling loads. The use of such clamps obviates welding of joints.
In one of the embodiments of the invention, the greenhouse structure comprises of structural members of rectangular cross section as against conventional round cross section members (Figure 6). This enables enhancing specific strength. It is the strength per unit weight of the structural member that results in the weight reduction of the structure as compared to the structures of the conventional greenhouses that have

round cross section members or bigger ones to achieve the same structural stability for the same load conditions.
The structural stability of the greenhouse structure of the present invention to sustain dead, live and wind load is investigated using finite element method. The objective and scope is to investigate the structural stability of the greenhouse structure of the present invention in terms of estimation of the forces in each of the members and its resilience to withstand the force and compare it with the structure that does not use the frame structure configuration of the present invention. The following Indian Standard Codes of Practice are referred to: IS 800 - 2007, General Construction in Steel - Code of Practice IS 875 (Part 3) - 1987, Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures, Part 3: Wind Loads The structural member forces are checked as per IS code procedure for safety. Following are the input load details:
The Dead Load on the frame is due to covering sheet and purlins connecting two frames. It is considered and estimated for this particular analysis as 0.025 kN/m2. Live Load is due to 'Piants' hung from the frame and occasional labour that would climb on the frame, it is considered and estimated for this particular analysis as 0.20 + 0.125 = 0.325 KN/m2. Wind Load is calculated based on the assumed velocity of 120 KM/Hr
The loads on frame are calculated as per procedures and ratios given in IS 875 - Part 3.
Figure 9 depicts that the structural members of the frame that does not use the greenhouse structure configuration of the present invention. Such a structure is conventionally known to be used. The analysis is conducted and following is the color code, based on ratios from the said model that corresponds to the safety of each member that is failure to withstand the load that is indicated in the Figure for each of the member.
Green Members indicates safe status Red member indicates highly unsafe status Blue member indicates moderately unsafe status
It is evident from the Figure 9 that plurality of roof members as well as column members are in red colour indicating unsafe status of the member, that is the member is not resilient and would not withstand the said loads and are therefore vulnerable to fail under such loads.

Figure 8 depicts the analysis of the structure configuration of the present invention based on the same colour codes.
It is evident that from the Figure 8 that all the members are in green colour indicating that ratios are nearly 1, which indicates safe status of each member.
The synergistic combination of the structural members, use of rectangular section for the members, a combination of proportions of total height, bay width, It is height of roof and the angle "CD" between slope of the roof and bay width results in a structurally stable greenhouse to withstand wind load, dead load, live loads and yet provide appropriately controlled ventilation, temperature, humidity and volume of air to facilitate plant growth.
it is evident that from the Figure 7 that an optimised clamping with one piece, broader pressed parts are provided without any wefding wherein the strength and the fife of clamp is increased at the same time they strengthen the Parent Member also, upon which clamps are mounted. Here clamps are ribbed & widened at selected locations & or plastic coated to enable higher strength & life compared to the conventional press parts of same weight.

We Claim:
1. A greenhouse structure comprising
Principal members comprising first and second principal curved members (30.
31), vertical principal member (36) and horizontal principal member (32);
Support members disposed to form nodes of triangular truss; columns; inclined
members; roof truss frame structure
wherein
the said principal curved members (30 and 31) are fastened to each other with
bracket;
the first curved member (30) extends to form a ventilator;
the extended portion of the first curved member (30) is supported by first and
second principal support members (40 and 41);
the said principal members are supported by secondary support members (33,
34, 35, 36, 37, 38, and 39) that are disposed vertically and diagonally to form
nodes at the ends of the members joined with each other to form a truss with
triangular module;
a module compring, of the roof truss frame configuration (300), ( two columns
four Sun Truss members (10, 20, 30,40) to form a Sun Trusses.
2. A greenhouse structure as claimed in claim 1 comprising
roof truss frame configuration (300)
first and second principal curved members (30. 31),
a vertical principal member (36),
a horizontal principal member (32),
wherein the said principal curved member 30 and 31 are joined with each other
with bracket;
the first curved member (30) extends to form a ventilator;
the extended portion of the first curved member (30) is supported by first and
second principal support members (40 and 41);
the said principal members are supported by secondary support members (33,
34, 35, 36, 37, 38, and 39) that are disposed vertically and diagonally to form
nodes at the ends of the members joined with each other to form a truss with
triangular module and form "M" configuration.
3. A greenhouse structure as claimed in claim 1-2 comprising
roof truss frame configuration (300)
first and second principal curved members (30. 31),
Without a vertical principal member (36),
with a horizontal principal member (32),
wherein the said principal curved member 30 and 31 are joined with each other
with bracket;

the first curved member (30) extends to form a ventilator;
the extended portion of the first curved member (30) is supported by first and
second principal support members (40 and 41);
the said principal members are supported by secondary support members (34,
35, 37, and 38) that are disposed diagonally to form nodes at the ends of the
members joined with each other to form a truss with triangular module and form
"W" configuration.
4. A greenhouse structure as claimed in claims 1-3 wherein angle made by the said principal curved member 30 with horizontal level is in the range of 20 to 30 degrees.
5. A greenhouse structure as claimed in claims 1-4 wherein the intersection and in turn joining of the said principal second curved member (31) with the said principal first curved member (30) is at the vertical distance (h) from the said principal horizontal member (32) is in the range of 20 to 40% of the length of the said horizontal principal member (32).

6, A greenhouse structure as claimed in claims 1-5 wherein the roof truss frame structure configuration of the said vertical principal members, horizontal principal members, principal support members and secondary support members is in the form of the English letter M.
7, A greenhouse structure as claimed in claims 1-5 wherein the roof truss frame structure configuration of the said vertical principal members, horizontal principal members, principal support members and secondary support members is in the form of the English letter W.
8, A greenhouse structure as claimed in claims 1-7 comprising of columns (400) and inclined member (401);
a module comprising of the roof truss frame configuration (300), two columns
four Sun Truss members (10, 20, 30,40) to form a Sun Trusses;
the said inclined member (401) is in the form of a column bracing that is
provided along with the Sun Truss members (10, 20, 30, 40} together forming the
Sun rays when fitted in bracket on column
wherein
such modules are repeated as per the strength requirement for wind load &
expanse required for the greenhouse.
9. A greenhouse structure as claimed in claims 1-8 wherein the structure is
characterized by total height (H) , bay width (W), and roof height (H, ), "ф"

between slope of the roof and bay width, roof truss frame structure height (h), roof truss frame structure width (w).
10. A greenhouse structure as claimed in claims 1-9 wherein the ratio of "h/w" is in the range from 0.20 to 0.27; the ratio of H/W is in the range from 0.71 to 0.85, angle "CD" is in the range from 22 to 27°.
11. A greenhouse structure as claimed in claims 1-10 wherein clamps are ribbed & widened at selected locations & or plastic coated to enable higher strength & life compared to the conventional press parts of same weight.
12. A greenhouse structure as claimed in claims 1-11 wherein structural members are of rectangular cross section.
13. A greenhouse structure as claimed in claims 1-12 wherein structural members are of round cross section.
14. A greenhouse structure as claimed in claims 1, 8 wherein a module comprises of the roof truss frame configuration (300), two columns and four Sun Truss members (10, 20,30,40)
wherein plurality of the said modules are operably joined to extend the greenhouse structure.
15. A structure as claimed in claims 1, 14 wherein an optimised clamping with one
piece, broader pressed parts provided without any welding wherein the strength
and the life of clamp is increased at the same time strengthen the Parent
Member also, upon which clamps are mounted.