Roof structure for a grain bin
A roof for a large diameter grain bin is formed by roof rafters inclined from a top of the wall to a top ring, with sheet metal panels in an upper row extending from the ring to a circular bottom edge and a lower row extending from a circular top edge to the wall. A circular bracket of Z-shaped cross section is carried on the rafters by upstanding support legs and provides an upper flange engaging the bottom edge of the upper row and a lower flange engaging the top edge of the lower row and an interconnecting web portion. One or both rows are supported at a mid point on a cylindrical tube bent to form a circle butting the panels and supported from the rafters on leg members which include a center strap which can be bent around the tube and two legs bolted to the rafters.
1. A roof structure having an upstanding cylindrical wall comprising:
a plurality of roof rafters, each extending from a top edge of the wall to a top support member, with the rafters being angularly spaced around the wall and with each rafter being inclined upwardly and inwardly from the wall to the top support member;
at least one row of sheet metal panels connected edge to edge so as to cover at least part of the rafters and define a conical roof;
wherein there is provided at least one roof panel support member supported from the rafters above the rafters for supporting the panels of said at least one row of panels;
said roof panel support member being located at a position part way down the panels;
the roof panel support member being circular so as to engage all of the roof panels supported thereby substantially across the full width of each panel;
wherein the roof panel support member is supported from the rafters to hold the roof panel support member and the panels engaged thereby spaced upwardly from the rafters.
2. The roof structure according to claim 1 wherein the roof panel support member is formed from a tube bent to follow the circular shape of the roof at the panels.
3. The roof structure according to claim 2 wherein the tube is circular in cross section.
4. The roof structure according to claim 1 wherein the roof panel support member is supported from the rafters by support leg members, each of which extends upwardly from a respective one of the rafters to hold the roof panel support member and the panels engaged thereby spaced upwardly from the rafters.
5. The roof structure according to claim 4 wherein each support leg member is U-shaped to define a base arranged to wrap partly around the roof panel support member and first and second legs extending from the base, with the first and second legs of the support leg member each attached to the respective rafter.
6. The roof structure according to claim 5 wherein each support leg member has a receptacle into which the roof panel support member sits while the roof panel support member is supported from the rafter by the first leg which is attached to the rafter and while the second leg member is bent around the roof panel support member for attachment to the rafter.
7. The roof structure according to claim 4 wherein the roof panel support member comprises a cylindrical tube and each support leg member has the base thereof forming a semi-cylindrical strap portion bent around the tube and supported by the first and second legs.
8. The roof structure according to claim 7 wherein at least the first leg has a support receptacle at a bottom of the strap portion for supporting the tube above the respective rafter while the strap portion is bent around the tube by pulling the second leg.
9. The roof structure according to claim 5 wherein the support leg member is bolted between the first and second legs immediately underneath the roof panel support member so as to clamp the roof panel support member at the base.
10. A roof structure for a structure having an upstanding cylindrical wall comprising:
a plurality of roof rafters, each extending from a top edge of the wall to a top support member, with the rafters being angularly spaced around the wall and with each rafter being inclined upwardly and inwardly from the wall to the top support member;
a plurality of sheet metal panels connected edge to edge so as to cover the rafters and define a conical roof covering an open area within the wall;
the panels including an upper row of panels connected edge to edge and extending from the top support member to a circular bottom edge of the upper row spaced part way down the rafters;
the panels including a lower row of panels connected edge to edge and extending from a circular top edge of the lower row adjacent the circular bottom edge of the upper row to a circular bottom edge of the lower row;
and a bracket member carried on the rafters for supporting the circular bottom edge of the upper row and the circular top edge of the lower row;
the bracket member forming substantially a ring spanning the rafters at the circular bottom edge of the upper row and the circular top edge of the lower row;
the bracket member including an upper flange engaging the circular bottom edge of the upper row, a lower flange engaging the circular top edge of the lower row and an interconnecting web portion connecting the upper and lower flanges
wherein the bracket member is supported relative to the rafters at a position with the lower flange spaced upwardly from the rafters so as to support the circular top edge of the panels of the lower row spaced upwardly from the rafters.
11. The roof structure according to claim 10 wherein the bracket member is supported relative to the rafters on a plurality of support legs, with each leg being attached to a respective one of the rafters and standing upwardly therefrom to the bracket member.
12. The roof structure according to claim 10 wherein the upper and lower flanges of the bracket member are parallel and spaced by the height of the interconnecting web portion.
13. The roof structure according to claim 10 wherein the interconnecting web portion is imperforate and extends around the full periphery of the roof so as to act as a barrier to prevent penetration of moisture between the circular top edge of the lower row and the circular bottom edge of the upper row.
14. The roof structure according to claim 10 wherein there is provided at least one roof panel support member supported from the rafters at a height above the rafters for supporting the panels of at least one of the upper row of panels and the lower row of panels, said roof panel support member being located at a position part way down the panels, the roof panel support member being circular so as to engage all of the roof panels supported thereby substantially across the full width of each panel.
15. The roof structure according to claim 14 wherein the roof panel support member is formed from a tube bent to follow the circular shape of the roof at the panels.
16. The roof structure according to claim 15 wherein the tube is circular in cross section.
17. The roof structure according to claim 14 wherein the roof panel support member is supported from the rafters by support leg members, each of which extends upwardly from a respective one of the rafters to hold the roof panel support member and the panels engaged thereby spaced upwardly from the rafters.
18. The roof structure according to claim 17 wherein each support leg member is U-shaped to define a base arranged to wrap partly around the roof panel support member and first and second legs extending from the base, with the first and second legs of the support leg member each attached to the respective rafter.
19. The roof structure according to claim 18 wherein each support leg member has a receptacle into which the roof panel support member sits while the roof panel support member is supported from the rafter by the first leg which is attached to the rafter and while the second leg member is bent around the roof panel support member for attachment to the rafter.
20. The roof structure according to claim 18 wherein the roof panel support member comprises a cylindrical tube and each support leg member has the base thereof forming a semi-cylindrical strap portion bent around the tube and supported by the first and second legs.
21. The roof structure according to claim 20 wherein at least the first leg has a support receptacle at a bottom of the strap portion for supporting the tube above the respective rafter while the strap portion is bent around the tube by pulling the second leg.
22. The roof structure according to claim 18 wherein the support leg member is bolted between the first and second legs immediately underneath the roof panel support member so as to clamp the roof panel support member at the base.
23. The roof structure according to claim 14 wherein there is provided a first roof panel support member for supporting the upper row of panels and a second roof panel support member for supporting the lower row of panels.
24. The roof structure according to claim 10 wherein each of the roof rafters is formed from at least two rafter portions overlapped at a center part of the rafter between the upper and lower ends so that the center part is double thickness and therefore of increased strength and wherein the rafter portions are each formed of a profile which is Z-shaped in cross-section with a center web and two flanges at right angles to the center web such that the portions nest together in the overlapped center part with the center webs abutting.
25. The roof structure according to claim 24 wherein each of the flanges includes a turn-back portion at an angle to the respective flange.
26. The roof structure according to claim 25 wherein the flanges and the turn-back portions are arranged so that one flange of one portion fits inside a corresponding flange of the other portion.
27. The roof structure according to claim 26 wherein each portion has one flange shorter than the other flange by a sufficient distance such that one fits inside the other.
28. A roof structure for a structure having an upstanding cylindrical wall comprising:
a plurality of roof rafters, each extending from a top edge of the wall to a top support member, with the rafters being angularly spaced around the wall and with each rafter being inclined upwardly and inwardly from the wall to the top support member;
at least one row of sheet metal panels connected edge to edge so as to cover at least part of the rafters and define a conical roof;
wherein there is provided at least one roof panel support member supported from the rafters above the rafters for supporting the panels of said at least one row of panels;
wherein the roof panel support member is supported from the rafters by support leg members;
wherein the roof panel support member comprises a tube bent to follow the circular shape of the roof at the panels;
wherein each support leg member is an inverted U-shape with a base and first and second legs;
wherein the base forms a strap portion wrapped around the tube so as to follow an outside shape of the tube;
wherein the first and second legs of the support leg member are attached to a respective one of the rafters so as to stand upwardly therefrom to support the base and the tube;
and wherein the first and second legs each include at least one flange thereon to provide upward support for the tube.
29. The roof structure according to claim 28 wherein at least the first leg has a support receptacle at a bottom of the strap portion for supporting the tube above the respective rafter while the strap portion is bent around the tube by pulling the second leg.
30. The roof structure according to claim 28 wherein the support leg member is bolted between the first and second legs immediately underneath the tube so as to clamp the tube at the strap portion.
31. The roof structure according to claim 28 wherein the legs and the band portion are formed from an integral metal panel wherein said at least one flange of each leg is bent from the panel.
32. The roof structure according to claim 31 wherein said at least one flange of each leg comprises a pair of side flanges of each leg where each side flange includes an end edge at the tube which is shaped to match an exterior shape of the tube to support the tube.
33. The roof structure according to claim 28 wherein the tube is circular in cross-section and the strap portion is semi-cylindrical around the tube.