US20240060317A1

US20240060317A1 - Worker support apparatus for conical roof construction

Info

Publication number: US20240060317A1
Application number: US18/448,377
Authority: US
Inventors: Herman Rempel Neufeld
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-22
Filing date: 2023-08-11
Publication date: 2024-02-22
Also published as: CA3209275A1

Abstract

An apparatus supporting workers assembling a conical roof includes a central support column, a pivot frame pivotally supported at a top end of the support column, and a stair assembly having an upper end coupled to the pivot frame such that the stair assembly is pivotal together with the pivot frame relative to the support column. The lower end of the stair assembly is supported on wheels for rolling on the building floor. A worker support platform is also carried on the pivot frame to pivot with the stairs. A roof support frame extends above the pivot frame, in fixed relation to the support column to support an apex of the conical roof thereon while the stairs and platform remain pivotal. This arrangement ensures that the stair assembly can be easily aligned with any selected rafters of the roof during construction while remaining safely supported relative to the support column.

Description

This application claims the benefit under 35 U.S.C.119(e) of U.S. provisional application Ser. No. 63/399,807, filed Aug. 22, 2022.

FIELD OF THE INVENTION

The present invention relates to a work support apparatus arranged to support workers thereon when constructing a conical roof of a building, for example the roof of a grain storage bin having rafters that taper upwardly and radially inwardly from a perimeter edge to an apex of the roof, so that workers on the work support apparatus can perform work along the rafters of the conical roof.

BACKGROUND

A common type of storage building or silo for storing grain and the like includes an upright cylindrical perimeter wall that is enclosed at a top end by a conical roof that tapers upwardly and radially inwardly from a perimeter edge to an apex of the roof. In this instance, it is a known practice to assemble the rafters and exterior sheathing forming the conical roof near ground level or on a suitable foundation followed by lifting of the assembled roof in stages to construct sequential annular bands of the cylindrical perimeter wall below the roof at the various stages of lifting. Assembly of the conical roof typically involves use of a scaffold to support a fixed platform for workers in proximity to the apex of the roof together with a stair assembly for accessing the platform. One known stair assembly is supported at an upper end for rolling movement on the platform and at a lower end for rolling movement on the foundation. The rolling contact of the stair assembly relative to the platform is unconstrained such that the stair assembly can potentially roll over edges of the platform causing considerable damage and potential severe injury to workers.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a method of constructing a conical roof of a building, the method comprising:

- providing a worker support apparatus comprising (i) a support column having a bottom end and a top end, (ii) a pivot frame pivotally supported on the support column in proximity to the top end of the support column, and (iii) a stair assembly extending longitudinally between a lower end of the stair assembly supported on wheels and an upper end of the stair assembly;
- mounting the support column to extend upwardly from the bottom end supported on a floor of the building to the top end in proximity to an apex of the conical roof such that the pivot frame is pivotal relative to the support column about a vertical pivot axis;
- coupling the top end of the stair assembly to the pivot frame such that (i) the stair assembly is pivotal together with the pivot frame relative to the support column about said vertical pivot axis, and (ii) the lower end of the stair assembly is in proximity to a perimeter of the conical roof with the wheels arranged for rolling movement in a circumferential direction about the vertical pivot axis of the support column;
- rotating the stair assembly about the vertical pivot axis between a plurality of circumferentially spaced apart working locations and supporting workers on the stair assembly while constructing respective portions of the conical roof at each of the working locations.

The method may further include providing a worker platform supported on the support column in proximity to the top end in which the worker platform has a horizontal upper supporting surface arranged to support workers thereon and in which the worker platform is supported on the pivot frame for rotation relative to the support column about the vertical pivot axis together with the stair assembly.
The method may further include providing a worker platform supported on the support column in proximity to the top end in which the worker platform has a horizontal upper supporting surface arranged to support workers thereon and in which an uppermost tread at the upper end of the stair assembly is supported in proximity to a perimeter edge of the worker platform.
The method may further include (i) providing a roof support frame supported on the top end of the support column such that the pivot frame is supported on the support column at a location spaced below the roof support frame, and (ii) supporting the apex of the conical roof on the roof support frame.
The method may further include releasing the stair assembly from the pivot frame by an upward sliding movement of the upper end of the stair assembly relative to the pivot frame.
According to a second aspect of the invention there is provided a worker support apparatus for use with a conical roof of a building, the apparatus comprising:

- a support column having a bottom end arranged to be supported on a floor of the building and being arranged to extend upwardly from the bottom end to a top end of the support column located in proximity to an apex of the conical roof;
- a pivot frame pivotally supported on the support column in proximity to the top end of the support column such that the pivot frame is pivotal relative to the support column about a vertical pivot axis;
- a stair assembly extending longitudinally between an upper end and a lower end of the stair assembly;
- the upper end of the stair assembly being arranged to be coupled to the pivot frame such that the stair assembly is pivotal together with the pivot frame relative to the support column about said vertical pivot axis; and
- the lower end of the stair assembly being supported on wheels arranged for rolling movement in a circumferential direction about the vertical pivot axis of the support column.

Providing a pivot frame which is rotatable relative to the support column relative to which the top end of the stair assembly can be coupled so that the stair assembly pivots relative to the support column ensures that the stair assembly is constrained to a pivotal movement about an upright axis of the support column. This ensures that the stair assembly remains safely supported relative to the support column while also ensuring that the stair assembly can be easily aligned with any selected rafters of the roof assembly during construction by simply pivoting the stair assembly about the upright pivot axis of the support column.
Preferably a worker platform is supported on the support column in proximity to the top end in which the worker platform has a horizontal upper supporting surface arranged to support workers thereon. The worker platform is preferably supported on the pivot frame for rotation relative to the support column about the vertical pivot axis together with the stair assembly. Preferably an uppermost stair tread at the upper end of the stair assembly is supported in proximity to a perimeter edge of the worker platform.
Preferably the stair assembly is releasably coupled to the pivot frame. In this instance, the pivot frame may include a first mating connector and the upper end of the stair assembly may include a second mating connector arranged for releasable connection with the first mating connector to support the stair assembly on the pivot frame, in which the second mating connector is releasable from the first mating connector by upward sliding movement of the second mating connector relative to the first mating connector.
The support column may comprise a plurality of modular sections arranged to be stacked with one another such that the support column is adjustable in height by adding or removing one of the modular sections relative to the support column.
The support column may further comprise (i) a base portion at the bottom end for engaging the floor of the building, (ii) a mounting portion near the top end for pivotally supporting the pivot frame thereon, and (iii) an intermediate portion comprising a singular pole formed in one or more sections to extend vertically between the base portion and the mounting portion.
When the support column comprises (i) a base portion at the bottom end for engaging the floor of the building, (ii) a mounting portion near the top end for pivotally supporting the pivot frame thereon, and (iii) an intermediate portion formed in one or more sections to extend vertically between the base portion and the mounting portion, the base portion may further comprise a lifting assembly arranged to lift the intermediate portion of the support column supported on the base portion relative to the floor of the building.
Preferably the support column is arranged to be supported by guy wires extending between the support column and the floor of the building.
The apparatus may further include a roof support frame supported on the top end of the support column in which the roof support frame is arranged to support the apex of the conical roof thereon. The pivot frame is preferably supported on the support column at a location spaced below the roof support frame such that the pivot frame is pivotal relative to the roof support frame about the vertical pivot axis of the support column. The roof support frame may comprise a plurality of radial support arms extending radially from the vertical pivot axis of the support column. The radial support arms are preferably adjustable in length such that the roof support frame is adjustable in diameter.
When the roof includes a loading opening at the apex including a circular rim, the apparatus may further comprise a roof support collar arranged to be supported on the support arms concentrically with the vertical pivot axis, in which the roof support collar includes an annular upper supporting surface arranged to support the circular rim of the loading opening of the roof thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a partially constructed conical roof for a cylindrical storage bin;

FIG. 2 is a perspective view of the conical roof once the roof has been assembled and partially lifted relative to the foundation for assembling the cylindrical perimeter wall in stages;

FIG. 3 is a perspective view of the assembled storage bin incorporating the conical roof therein;

FIG. 4 is a sectional view of the conical roof along the line 4-4 in FIG. 1 during construction of the roof in which the worker support apparatus is shown mounted within the interior of the roof to support workers constructing the roof;

FIG. 5 is a top plan view of the worker support apparatus shown relative to the perimeter cylindrical wall of the storage bin;

FIG. 6 is an enlarged side view of the upper mounting portion of the support column of the worker support apparatus including the roof support frame, the worker platform on the pivot frame, and the upper end of the stair assembly on the pivot frame;

FIG. 7 is a top view of the worker platform of the worker support apparatus along the line 7-7 in FIG. 6 ; and

FIG. 8 is a sectional view of the pivot frame of the worker support apparatus along the line 8-8 in FIG. 6 .

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION

Referring to the accompanying figures, there is illustrated a worker support apparatus generally indicated by reference numeral 10. The apparatus 10 is particularly suited for supporting workers during construction of a conical roof 12 of a building 14, for example a grain storage bin as shown in the accompanying figures.
In the illustrated example, the roof 12 tapers upwardly and radially inwardly from a circular perimeter edge 16 at the bottom where the roof is supported on a cylindrical perimeter wall 18 of the bin, to a central apex 20 at the top of the bin. A loading opening 22 is provided at the apex where a circular rim 24 forms the perimeter boundary of the loading opening. A hatch cover is typically subsequent mounted over the opening 22 to form a lid over the opening upon completion of the bin construction. The roof further includes a plurality of rafters 26 which extend radially between the perimeter edge 16 and the circular rim 24 at the apex 20 of the roof at circumferentially spaced positions about the roof. Subsequent to assembly of the rafters, suitable sheathing material 28 spans the top side of the rafters to form the outer boundary of the roof.
For larger bins, the bin is typically supported on a suitable foundation 30 such as a concrete base defining a main floor of the constructed bin. In some instances, an access passage may be provided within the concrete base below the main floor of the bin with a central passage communicating vertically between the access passage below the main floor and the hollow interior of the bin. In this instance the lower boundary of the access passage below the bin forms an auxiliary floor surface spaced below the main floor of the bin.
Construction of the roof of the bin is typically accomplished at ground level as shown in FIG. 1 in which the rafters are connected between the circular rim 24 at the apex and an upper portion 32 of the cylindrical wall of the bin which is also initially assembled at ground level. Once the rafters are assembled, the sheathing material 28 can be mounted onto the rafters as further shown in FIG. 1 . Once the roof is complete, the roof is then raised relative to the foundation in stages. A plurality of lifting cylinders 34 are provided at circumferentially spaced positions about the bin structure for actuation by a common hydraulic circuit to uniformly lift the roof by a prescribed amount relative to the foundation. The prescribed amount corresponds to the height of one annular portion of the cylindrical wall 18 of the bin. Each stage of the bin wall construction thus involves lifting of the roof by the prescribed amount, followed by construction of one annular portion of the cylindrical wall as shown in FIG. 2 . Upon completion of one annular portion of the cylindrical wall, the lifting cylinders 34 are then reattached to the newly constructed annular portion to lift the roof by the prescribed amount once more to permit construction of a subsequent portion of the cylindrical wall of the bin. A completed cylindrical bin constructed according to the present invention is illustrated in FIG. 3 .
The worker support apparatus 10 according to the present invention is primarily used while the roof remains under construction at ground level as shown in FIG. 1 . As shown in FIG. 4 , the apparatus 10 generally includes (i) a central support column 36 arranged to substantially span the height of the conical roof between a floor surface of the foundation and the apex of the roof during the initial assembly stage of FIG. 1 , (ii) a pivot frame 38 which is pivotally mounted on the support column in proximity to the top end thereof so as to be pivotal about a vertical pivot axis relative to the support column, (iii) a roof support frame 40 mounted in fixed relation to the support column 36 at the top end thereof at a location spaced above the pivot frame 38 for supporting the circular rim 24 at the apex of the roof thereon during roof construction, and (iv) a stair assembly 42 extending longitudinally between an upper end 44 arranged to be fixed onto the pivot frame 38 for pivotal movement of the stair assembly with the pivot frame about the vertical pivot axis of the support column and a lower end 46 supported for rolling movement along a corresponding floor surface of the bin structure in a circumferential direction about the vertical pivot axis of the support column.
The support column 36 generally includes (i) a base portion 48 at the bottom end for being engaged upon a floor surface of the bin, (ii) a mounting portion 50 at the top end which supports the pivot frame 38 and the roof support frame 40 thereon, and (iii) an intermediate portion 52 formed in modular sections 54 stacked to form a singular pole connected between the base portion 48 at the bottom of the column and the mounting portion 50 at the top of the column.
The base portion includes two floor beams 56 mounted perpendicularly to one another to form a stable base lying a common horizontal plane for engagement on the floor surface of the bin. An inner post 58 extends vertically upward from the intersection of the two floor beams in fixed relation to the floor beams. An outer sleeve 60 has a cross-section which matches the cross-section of the inner post 58 and includes an inner dimension closely matching the outer dimensions of the inner post 58 such that the outer sleeve 60 can be slid over top and along the inner post 58 received therein.
A lift assembly of the base portion comprises two hydraulic actuators 62 which are mounted parallel to the inner post at diametrically opposing sides thereof so that each hydraulic actuator is connected at a bottom end to one of the floor beams and at a top end on a crossbar that is fixed to the outer sleeve 60 at an intermediate location along the height thereof. The actuators 62 are connected to a common hydraulic circuit such that the actuators can be activated together to commonly lift the outer sleeve 60 relative to the inner post 50 on the floor being 56. In this instance, a plurality of modular sections of the intermediate portion of the support column can be selected to be near to the desired height of the apex of the roof and assembled to locate the roof support frame 40 in close proximity to the desired height of the apex. The lift assembly can then be used to further extend the support column and raise the roof support frame 40 to the desired height relative to the conical roof of the building.
The modular sections 54 of the support column each comprise an elongate tubular sleeve which is hollow and open at both ends. A plurality of couplers 64 are provided for connecting each end of each modular section to an adjacent modular section or the base portion below or mounting portion above. Each coupler comprises an elongate post having outer dimensions closely matching the inner dimensions of the sleeves of the modular sections 54 to permit the post to be slidably inserted into the abutted ends of two modular sections 54. A stop collar 66 is provided at a central location along the post forming the coupler in which the collar 66 has an outer dimension closely matching the outer dimension of the sleeves 54. In this manner the collar 66 functions as a stop which controls the amount of insertion of the post of the coupler 64 into each of the two sleeves 54 being coupled by the coupler. The coupler 64 can be coupled to the top end of the outer sleeve 60 of the base portion in the same manner. The coupler 64 can also be coupled in the same manner by insertion into the open bottom end of a corresponding main sleeve 68 of the mounting portion above.
The mounting portion 50 of the support column includes the main sleeve 68 thereof at a central location which has cross-sectional dimensions similar to the sleeves 54 of the intermediate portion 52. The main sleeve 68 of the mounting portion supports a bearing plate 70 at an intermediate location on the main sleeve in the form of a circular plate which is welded about the main sleeve 68. The bearing plate lies perpendicular to the vertical pivot axis of the support column and defines an upward facing annular bearing surface that supports a pivot sleeve 72 of the pivot frame rotatably thereon. The pivot sleeve 72 has an outer diameter which is equal to or less than the outer diameter of the bearing plate so that a bottom annular rim of the pivot sleeve 72 is fully engaged upon the upper bearing surface of the bearing plate 70.
An inner circular rim 74 having an outer diameter closely matching the inner diameter of the pivot sleeve 72 is mounted on the upper surface of the bearing plate 70 to concentrically locate the pivot sleeve 72 relative to the bearing plate 70. The circular rim 74 is thus received into an open bottom end of the pivot sleeve 72. An upper centering plate 76 is welded to the main sleeve 68 at a location spaced above the bearing plate 70 in alignment with the top of the pivot sleeve 72. The outer diameter of the upper centering plate 76 is approximately equal to the inner diameter of the pivot sleeve while being mounted so that the top of the centering plate 76 is substantially flush with the top edge of the pivot sleeve. In this manner the outer peripheral edge of the centering plate is rotatably engaged with an inner surface of the pivot sleeve 72 to assist in concentrically locating the pivot sleeve 72 relative to the main sleeve 68 while permitting relative rotation therebetween. The mounting of the pivot sleeve 72 about the main sleeve 68 by the bearing plate 70 and the upper centering plate 76 effectively defines a pivot coupling between the pivot frame and the mounting portion 50 of the support column. The pivot sleeve 72 span substantially the full height of the pivot coupling.
The roof support frame 40 includes a centre post 78 having an outer dimension which closely fits within the inner dimension of the main sleeve 68 of the mounting portion of the column therebelow. The centre post 78 is square in cross-section to mate with a corresponding square cross-section of the main sleeve 68 below to form a non-rotatable mating connection therebetween. This is similar to the mating non-circular cross-sectional shapes of the modular sections 54 of the intermediate portion of the support column and the posts of the couplers 64 connecting the modular sections of the support column from the base portion 48 to the mounting portion 50 so that all of the components have a square cross-section to be coupled non-rotatably relative to one another from the bottom of the base portion to the top of the roof support frame with the exception of the rotatably support of the pivot frame.
The roof support frame 40 further includes a stop collar 80 which is fixed about the exterior of the centre post 78 at a location spaced upwardly from the bottom end thereof. The stop collar has an outer dimension which is approximately equal to the outer dimension of the main sleeve 68 such that the stop collar is abutted with the top end of the main sleeve 68 and the bottom portion of the centre post 78 is received within the main sleeve 68 by a prescribed overlapping amount. A majority of the centre post 78 extends above the stop collar to the top end of the support frame.
Four radial arms 82 extend radially outward from the top end of the centre post 78 at evenly spaced apart positions in the circumferential direction such that the four radial arms are offset 90 degrees apart from one another. Each radial arm 82 is a hollow tube protruding perpendicularly and radially outward from the centre post. An extension tube 84 is slidably received through the open end of the main tube of each radial arm 82 and supports a hook flange 86 at the outer end thereof which protrudes upwardly above the top side of the corresponding radial arm 82 to form an upwardly protruding flange that functions to hook a portion of the circular rim 24 of the apex of the roof thereon in some instances. A suitable setscrew threaded through the hollow tube of each radial arm or a latch pin inserted through cooperating apertures in the extension tube 84 and the corresponding radial arm 82 permits the extension tube to be fixed at a selected position relative to the radial arm for adjusting the length of the radial arms and in turn adjusting an overall diameter of the roof support frame.
When the circular rim at the apex of the roof includes a depending flange, the depending flange may be directly engaged upon the radial arms 82 while being retained by the hook flanges 86. Alternatively, as shown in the illustrated embodiment, when the circular rim 24 of the roof has a sloped bottom surface, an adapter may be provided for centering the rim 24 relative to the roof support frame 40. The adapter comprises a roof support collar 88 having a diameter which is matched to the diameter of the rim of the bin roof. Different sizes of adapters may be provided for different bin sizes. The collar 88 of the adapter is positioned on the radial arms of the roof support frame with the position of the hook flanges 86 selected to contain and concentrically locate the collar 88 relative to the roof support frame.
A plurality of support flanges 90 are provided at spaced positions about the perimeter of the roof support collar 88. Each support flange 90 comprises a top plate which is sloped downwardly and radially outwardly from an inner end supported on the outer side of the collar 88 to an outer end spaced radially outward from the collar, and a bottom plate below the top plate. The bottom plate of the support flange 90 extends horizontally outward from the collar 88 at a location spaced below the top plate to an outer end joined to the outer end of the top plate to rigidly support the top plate relative to the collar. The top plates of the support flanges 90 collectively form a conical support surface matching the slope of the circular rim 24 of the bin roof supported thereon.
The pivot frame 38 further includes two main beams 92 which are supported spaced apart and parallel to one another at diametrically opposing sides of the vertical pivot axis to lie in a common horizontal plane that is perpendicular to the pivot axis. The main beams 92 are supported relative to the pivot sleeve 72 of the pivot frame by a pair of connecting arms 94 respectively. The connecting arms 94 extend radially outward from the pivot sleeve 72 at diametrically opposed locations to lie along a common diametrical axis relative to the pivot axis. Each connecting arm 94 mounts a respective one of the main beams 92 at an outer end thereof so that the beam extends perpendicularly across the end of the connecting arm 94. An additional brace arm 96 is connected between each connecting arm 94 and a location on the pivot sleeve directly above the connection of the corresponding connecting arm 94 to the pivot sleeve. The connecting arms 94 and the main beams 92 collectively form an H-shaped subframe mounted externally on the pivot sleeve 72 of the pivot coupling.
At one end of the subframe formed by the main beams 92 there is formed a coupling arrangement for connecting the upper end of the stair assembly onto the pivot frame. An upright collar 98 is mounted on one end of each of the main beams 92. Each collar extends about an upright axis having an open top end defining a first mating connector arranged to receive a corresponding second mating connector 100 of the stair assembly therein.
More particularly, the upper end of the stairs is supported on a horizontal crossbeam 102 forming the upper end of the stair assembly. Two posts extend vertically downward from laterally opposing ends of the crossbeam 102 to define the second mating connectors 100. The posts 100 are vertically oriented when the stair assembly is supported at the desired slope in an assembled configuration. The posts 100 mate with the collars 98 on the pivot frame for vertical sliding movement therebetween such that the stairs are coupled to the pivot frame by sliding the second mating connectors 100 of the stair assembly vertically downward into the open top ends of the collars 98 forming the first mating connectors on the pivot frame. Releasing the stair assembly from the pivot frame involves sliding the second mating connectors 100 vertically upward and out of the collars 98 forming the first mating connectors on the pivot frame. The posts 100 are fixed onto the crossbeam 102 at a horizontal spacing corresponding to the spacing between the collars 98 for alignment therebetween.
The apparatus 10 further includes a worker platform 104 which is mounted on the pivot frame to pivot together with the stair assembly and the pivot frame about the vertical pivot axis relative to the support column. The worker platform 104 defines an upper supporting surface arranged to support workers thereon during construction of the roof. The worker platform 104 includes a perimeter floor portion 106 in the form of a rigid sheet having a central opening therein so that the rigid sheet is generally annular about the opening. The sheet is mounted onto the top side of the main beams so as to be horizontally oriented. The perimeter floor portion 106 spans the full length and full width of the pivot frame to protrude outwardly therefrom in a cantilevered manner along two opposing sides and along one end longitudinally opposed from the coupling arrangement where the stairs are connected. The rigid sheet forming the perimeter floor portion 106 can be joined to the top side of the main beams of the pivot frame by various means including connecting flanges, support braces 108 or gussets of various forms. The perimeter floor portion 106 forms an annular perimeter portion of the upper supporting surface of the worker platform that supports workers thereon.
An edge flange 110 is mounted about the perimeter of the floor portion 106 to form a lip protruding upwardly above the upper supporting surface that supports workers thereon. The edge flange 110 extends about the full perimeter of the worker platform with the exception of a gap in the perimeter that is aligned with the stairs between the two collars 98 forming the coupling arrangement to the stair assembly.
A railing assembly is also mounted about the perimeter of the floor portion 106 with the exception of the gap in the perimeter that is aligned with the stairs as described above. The railing assembly includes a plurality of posts 112 which are fixed to the edge flange 110 to extend upwardly therefrom and a plurality of railing members 114 connected between adjacent ones of the posts at different elevations while remaining open at the gap between the first mating connectors 98 for the stair assembly.
The worker platform further includes a plurality of floor panels 116 which enclose the central opening in the perimeter floor portion 106. The floor panels 116 each comprise an elongate member which is mounted to extend in a lateral direction to be supported at opposing ends on the top side of the two main beams 92 respectively. The floor panels fit within the cavity defined by the perimeter floor portion 106 so that the floor panels are fully surrounded by the perimeter floor portion 106. Each floor panel spans the width of the cavity in the lateral direction that is perpendicular to the beams 92. A sufficient number of floor panels are provided so that the floor panels are abutted side-by-side in the longitudinal direction of the beams 92 so that the collective width of all the floor panels fits closely within the longitudinal dimension of the cavity in the perimeter floor portion 106 to constrain the floor panels in the longitudinal direction of the beams 92.
The floor panels 116 each include a flat upper surface lying in a common plane with the other panels and in a common plane with the perimeter floor portion 106 so that the floor panels 116 and the perimeter floor portion 106 collectively define the entirety of the upper supporting surface of the worker platform that supports workers thereon. Each floor panel is formed of a rigid sheet material formed in an inverted U shape in cross-section so as to comprise a top bridge plate spanning the length of the floor panel between the opposing ends and two side flanges depending down from opposing sides of the bridge plate along the full length of the floor panel so that the side flanges of the panels are engaged upon the top side of the main beams 92 in a mounted position.
The stair assembly 42 includes two stringers 118 which collectively span the full length of the stair assembly in the longitudinal direction between an upper end at the crossbeam 102 and an opposing lower end joined by a lower crossbeam 120. The stringers are formed in modular sections which can be readily attached to one another or disassembled for transport. Furthermore, the number of modular sections connected between the upper and lower ends of the stair assembly can be adjusted to vary the overall length of the stair assembly according to the size of the bin being constructed. Each modular section includes a plurality of stair treads 122 connected laterally between the two stringers so that the sections of the stringers and the treads connected therebetween form a fixed rigid frame. A suitable railing structure 124 is also mounted along both sides of each modular section of the stair assembly so that the railing extends upward from the stringers 118 respectively.
An uppermost modular section of the stair assembly supports the upper crossbeam 102 spanning between the two stringers thereof, while a lowermost modular section of the air assembly supports the bottom crossbeam 120 extending between the two stringers of that modular stair section. Intermediate modular sections of the stair assembly between the top and bottom sections are otherwise substantially identical to one another and interchangeable with one another. In the mounted position of the stair assembly, an uppermost tread among the stair treads 122 is located in close proximity to a perimeter edge of the worker platform 104 at a similar elevation to one another.
The bottom crossbeam 120 is supported along the bottom of the stringers to extend laterally across the width of the stair assembly and protrude outwardly beyond the stringers at both opposing ends of the bottom crossbeam 120. A vertical leg 126 extends downward from each end of the bottom crossbeam 120 to supports an axle at the bottom end of each leg which in turn supports a dual wheel set 128 thereon for rolling movement along the floor surface of the bin while supporting the bottom end of the stringers spaced above the floor. The dual wheels at each end of the bottom crossbeam 120 are oriented for rolling movement perpendicularly to the longitudinal direction of the stair assembly corresponding to a circumferential direction about the vertical pivot axis of the upright support column.
The apparatus 10 is typically provided in the form of a kit of parts ready to be assembled such that the kit of parts can be readily transported between different job sites. Before construction of the roof begins, a centre of the bin is located on the bin floor so that the support column can be assembled on the bin floor in concentric alignment with the desired location of the cylindrical wall of the bin and the roof thereabove. The support column is assembled in sections stacked one above the other with the worker platform 104 fixed onto the mounting portion and the pivot frame rotatably supported on the mounting portion of the support column. A set of guy wires 130 are connected between the intermediate portion of the support column and the floor surface of the bin foundation at a plurality of circumferentially spaced positions to maintain the support column in a vertical orientation relative to the bin structure.
The stair assembly can then be assembled and attached to the pivot frame at the upper end by inserting the second mating connectors of the stair assembly vertically downward into the collars 98 forming the first mating connectors on the pivot frame. Using access provided by the stairs, the railings and the floor panels of the worker platform can then be mounted in place followed by attachment of the roof support member onto the top end of the support column.
Once the apparatus has been assembled, construction of the roof begins by positioning the circular rim for the apex of the roof on the roof support member at the top of the apparatus. The stairs are positioned at a slope corresponding approximately to the slope of the roof so that the stairs can be located immediately below each rafter being assembled from the perimeter edge to the apex of the roof. Upon assembly of each rafter, the stair assembly is rotated about the vertical pivot axis of the support column to the next rafter location to permit assembly of the next rafter while workers are supported on the stair assembly and/or the worker platform 104. Once all of the rafters have been assembled, the stair assembly can then be further pivoted to each rafter location for ease of attachment of exterior sheathing onto the exterior of the rafters. Once all of the sheathing has been mounted and the construction of the roof is complete, the apparatus 10 can be disassembled and the remainder of the cylindrical wall of the bin is constructed by jacking up the roof in stages using the perimeter lift cylinders 34 as described above.
Since various modifications can be made in the invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

Claims

1. A worker support apparatus for use with a conical roof of a building, the apparatus comprising:

a support column having a bottom end arranged to be supported on a floor of the building and being arranged to extend upwardly from the bottom end to a top end of the support column located in proximity to an apex of the conical roof;

a pivot frame pivotally supported on the support column in proximity to the top end of the support column such that the pivot frame is pivotal relative to the support column about a vertical pivot axis;

a stair assembly extending longitudinally between an upper end and a lower end of the stair assembly;

the upper end of the stair assembly being arranged to be coupled to the pivot frame such that the stair assembly is pivotal together with the pivot frame relative to the support column about said vertical pivot axis; and

the lower end of the stair assembly being supported on wheels arranged for rolling movement in a circumferential direction about the vertical pivot axis of the support column.

2. The apparatus according to claim 1 further comprising a worker platform supported on the support column in proximity to the top end, the worker platform having a horizontal upper supporting surface arranged to support workers thereon.

3. The apparatus according to claim 2 wherein the worker platform is supported on the pivot frame for rotation relative to the support column about the vertical pivot axis together with the stair assembly.

4. The apparatus according to claim 2 wherein an uppermost stair tread at the upper end of the stair assembly is supported in proximity to a perimeter edge of the worker platform.

5. The apparatus according to claim 1 wherein the stair assembly is releasably coupled to the pivot frame.

6. The apparatus according to claim 5 wherein the pivot frame includes a first mating connector and the upper end of the stair assembly includes a second mating connector arranged for releasable connection with the first mating connector to support the stair assembly on the pivot frame, the second mating connector being releasable from the first mating connector by upward sliding movement of the second mating connector relative to the first mating connector.

7. The apparatus according to claim 1 wherein the support column comprises a plurality of modular sections arranged to be stacked with one another such that the support column is adjustable in height by adding or removing one of the modular sections relative to the support column.

8. The apparatus according to claim 1 wherein the support column comprises:

a base portion at the bottom end for engaging the floor of the building;

a mounting portion near the top end for pivotally supporting the pivot frame thereon; and

an intermediate portion comprising a singular pole formed in one or more sections to extend vertically between the base portion and the mounting portion.

9. The apparatus according to claim 1 wherein the support column comprises:

a base portion at the bottom end for engaging the floor of the building;

an intermediate portion formed in one or more sections to extend vertically between the base portion and the mounting portion;

the base portion further comprising a lifting assembly arranged to lift the intermediate portion of the support column supported on the base portion relative to the floor of the building.

10. The apparatus according to claim 1 wherein the support column is arranged to be supported by guy wires extending between the support column and the floor of the building.

11. The apparatus according to claim 1 further comprising a roof support frame supported on the top end of the support column, the roof support frame being arranged to support the apex of the conical roof thereon.

12. The apparatus according to claim 11 wherein the pivot frame is supported on the support column at a location spaced below the roof support frame such that the pivot frame is pivotal relative to the roof support frame about the vertical pivot axis of the support column.

13. The apparatus according to claim 11 wherein the roof support frame comprises a plurality of radial support arms extending radially from the vertical pivot axis of the support column.

14. The apparatus according to claim 13 wherein the radial support arms are adjustable in length such that the roof support frame is adjustable in diameter.

15. The apparatus according to claim 13 wherein the roof comprises a loading opening at the apex including a circular rim, the apparatus further comprising a roof support collar arranged to be supported on the support arms concentrically with the vertical pivot axis, the roof support collar including an annular upper supporting surface arranged to support the circular rim of the loading opening of the roof thereon.

16. A method of constructing a conical roof of a building, the method comprising:

providing a worker support apparatus comprising (i) a support column having a bottom end and a top end, (ii) a pivot frame pivotally supported on the support column in proximity to the top end of the support column, and (iii) a stair assembly extending longitudinally between a lower end of the stair assembly supported on wheels and an upper end of the stair assembly;

mounting the support column to extend upwardly from the bottom end supported on a floor of the building to the top end in proximity to an apex of the conical roof such that the pivot frame is pivotal relative to the support column about a vertical pivot axis;

coupling the top end of the stair assembly to the pivot frame such that (i) the stair assembly is pivotal together with the pivot frame relative to the support column about said vertical pivot axis, and (ii) the lower end of the stair assembly is in proximity to a perimeter of the conical roof with the wheels arranged for rolling movement in a circumferential direction about the vertical pivot axis of the support column;

rotating the stair assembly about the vertical pivot axis between a plurality of circumferentially spaced apart working locations and supporting workers on the stair assembly while constructing respective portions of the conical roof at each of the working locations.

17. The method according to claim 16 further comprising providing a worker platform supported on the support column in proximity to the top end in which the worker platform has a horizontal upper supporting surface arranged to support workers thereon and in which the worker platform is supported on the pivot frame for rotation relative to the support column about the vertical pivot axis together with the stair assembly.

18. The method according to claim 16 further comprising providing a worker platform supported on the support column in proximity to the top end in which the worker platform has a horizontal upper supporting surface arranged to support workers thereon and in which an uppermost tread at the upper end of the stair assembly is supported in proximity to a perimeter edge of the worker platform.

19. The method according to claim 16 further comprising:

providing a roof support frame supported on the top end of the support column such that the pivot frame is supported on the support column at a location spaced below the roof support frame; and

supporting the apex of the conical roof on the roof support frame.

20. The method according to claim 16 further comprising releasing the stair assembly from the pivot frame by an upward sliding movement of the upper end of the stair assembly relative to the pivot frame.