MAST CLIMBING WORK PLATFORM FOR BLAST FURNACE MAINTENANCE

The present invention relates to a work platform system, and, more particularly, to an elevatable mast climbing work platform system for use in blast furnace repair or construction.

BACKGROUND OF THE INVENTION

Elevated working platforms are well known in the art and are commonly used during construction to support workers and equipment at desired elevations. Platforms of this nature include moveable elevating platform assemblies as well as stationary scaffolding.

Elevating platform assemblies are typically supported by a single column or multiple columns that are in turn supported by concrete pads or structural steel plates. With the use of a hydraulic rack and pinion power system or lifting hook mechanism, the elevating platform assembly uses horizontal braces of the structural columns to "climb" vertically, thus raising workers and materials to a desired elevation.

However, there are problems inherent in such arrangements. For example, when additional materials or personnel are to be moved to or from the elevation where the work is taking place to loading area, the entire platform assembly, and everything on it, is moved, thus interrupting the progress of workers already working on the platform, since they will not be in a position to continue working until the platform assembly has returned from the loading area back to the original elevation. As a result, the work flow can be adversely affected.

Furthermore, in situations such as that typically encountered within a blast furnace, where the interior wall

surface thereof possesses variations in width along its vertical extent, such platform assemblies do not function well. This is because such a platform assembly may, if positioned at a certain elevation level, be close or adjacent to a surface or structure under repair, but, if repositioned to another elevation level having a different width, may no longer be close to or adjacent to the surface or structure, making it problematic for workers to effect repairs thereto. In some instances, there may be parts of the blast furnace wall that cannot be accessed because the platform is larger than the width of the blast furnace.

As a result, with respect to work platform systems for use in servicing the interior of a blast furnace, conventional approaches to blast furnace repair have typically involved using scaffolding lowered from the top of the blast furnace. Use of such scaffolding is also problematic, however, since these systems are also constantly raised and lowered to desired elevation levels, with the attendant disadvantages as discussed above. Additionally, they extend along only a portion of the structure and are moved around the perimeter of the structure to get from one spot to another, resulting in an even more time- consuming, costly and tedious process.

Further, such systems are particularly ill-suited to blast furnace maintenance operations because they typically utilize a rectangular working platform. As a result, only the end points remain adjacent to the curved cross-section of the interior wall of the blast furnace, while a crescent-shaped gap extends between the blast furnace wall and the platform intermediate these end points. Depending upon the radius of curvature and the length of the platform, such gaps could be quite large, thus

inhibiting the ability to service the blast furnace wall and potentially restricting the length of the platform.

Additionally, as the floor and interior walls of blast furnaces are delicate and as the integrity of the wall is a significant aspect of the performance of the blast furnace, care should be taken to avoid scratching or otherwise defacing it, either with tools or, indeed, the end portions of the rectangular work platform, as it is moved up and down and about the perimeter of the wall.

Still further, most blast furnaces have a substantially inverted truncated conical configuration that extends from a minimum inside diameter of approximately 27 feet to a maximum inside diameter of approximately 40 feet. As such, a work platform that is suspended from the narrower top of the furnace is not easily brought into close proximity to the wider bottom part of the furnace, or precisely positioned thereabout.

It would therefore be advantageous to have an improved work platform system for use in blast furnace repair that enables materials and/or personnel to travel to or from a work platform at a selected elevation where the work is taking place to a loading area, without substantially moving the entire work platform from the selected elevation.

It would be further advantageous to develop an improved work platform system that minimally impacts the floor and walls of the structure being serviced.

It would be still further advantageous to have an improved work platform system, which permits access to all parts about the wall of the structure at a given elevation, without repositioning and without substantial gaps between the wall and

the platform, and which is able to quickly conform to and accommodate variances in the width of the blast furnace interior at differing elevations, including a substantially inverted truncated conical configuration.

SUMMARY OF THE INVENTION

The present invention discloses an elevatable mast climbing work platform system for use in blast furnace repair, which enables a transport elevator carrying materials and/or personnel to travel to or from a working platform at a selected elevation in the blast furnace interior to a ground surface, without substantially moving the working platform from the selected elevation.

The present invention further has a circular elevatable working platform having an adjustable diameter that is able to quickly conform to and substantially accommodate variations in the width of the blast furnace interior along its vertical extent with substantially no gap between the platform and the wall.

According to a first broad aspect of an embodiment of the present invention, there is disclosed a mast climbing work platform system for providing access to a point at a height along an interior wall surface of a structure, the wall surface extending substantially vertically from a bottom and having varying perimeters along its vertical extent, the system comprising a base portion positioned inside the wall surface; a tower mast secured to and extending substantially vertically above the base portion to at least substantially a height of the point; a substantially horizontal platform secured to the tower mast and vertically movable therealong, whereby the platform is

adapted to extend to at least substantially the height of the point and having a perimeter expandable to a size whereby access may be provided therefrom to the point on the wall surface; and an elevator secured to the tower mast and vertically moveable therealong and adapted to extend at least to substantially a height of the platform, whereby personnel and materials may be delivered to and from a loading area of the structure.

According to a second broad aspect of an embodiment of the present invention, there is disclosed a mast climbing work platform kit for providing access to a point at a height along an interior wall surface of a structure comprising a base portion; a tower mast adapted to be secured to and to extend substantially vertically above the base portion to at least substantially a height of the point; a platform adapted to be secured to the tower mast for vertical movement therealong and for extension to at least substantially the height of the point, and having an adjustable perimeter whereby the platform can be adjusted to assume a size whereby access may be provided therefrom to the point on the interior wall surface; and an elevator adapted to be secured to the tower mast for vertical movement therealong and adapted to extend at least to substantially a height of the platform.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention will now be described by reference to the following figures, in which identical reference numerals in different figures indicate identical elements and in which:

Figure 1 is a perspective view, partially cut-away, of an exemplary embodiment of the present invention; and

Figure 2 is a perspective view from above of the platform of Figure 1, which illustrates, in a cut-away and expanded view, components of the platform.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described for the purposes of illustration only in connection with certain embodiments; however, it is to be understood that other objects and advantages of the present invention will be made apparent by the following description of the drawings according to the present invention. While a preferred embodiment is disclosed, this is not intended to be limiting. Rather, the general principles set forth herein are considered to be merely illustrative of the scope of the present invention and it is to be further understood that numerous changes may be made without straying from the scope of the present invention.

Referring to Figure 1, there is shown a mast climbing work platform system shown generally at 1 in accordance with an exemplary embodiment of the present invention, for use within a blast furnace 2. The inventive system 1 comprises a base portion 10, a tower mast 20, a construction elevator 30 and a platform 40.

The base portion 10 rests on a ground surface within the interior of the blast furnace 2, which is typically a graphite brick surface or the residual salamander or steel build up within the interior of the blast furnace, and preferably on a packed sand base to provide a level foundation while minimally impacting and protecting the surface of the blast furnace floor 5.

It will also be readily apparent to one skilled in the art that the base portion 10 could conceivably be mounted and secured upon the ground level of the blast furnace 2, by means of anchor bolts, for example. After removal from the floor, the disturbances caused by so securing the base portion thereto would be remediated.

The base portion 10 is preferably a structural steel plate, and is used to support the mast climbing work platform system 1 of the present invention, as hereinafter described. It will also be readily apparent to those having ordinary skill in this art that, for example, a concrete pad could also be utilized as a base portion 10.

The tower mast 20 is connected to and mounted upon the base portion 10 and extends vertically therefrom along a central axis 21, the size and the height of the tower mast 20 being governed by a variety of factors, such as, for example, the height and desired clearance of the interior of the blast furnace 2 itself.

The base portion 10 supports the tower mast 20 in fixed, perpendicular engagement therewith. The tower mast 20 is preferably welded to the base portion 10, though it will also be readily apparent to one skilled in the art that the tower mast 20 could also be mounted and secured upon the base portion 10 by other means, such as bolts.

If desired, the tower mast 20 could be secured and mounted to interior wall surfaces 4 of the blast furnace 2 at various points along its length thereof, using reinforcing bars, structural steel or cables (not shown) , so as to provide further stability and support, particularly if the tower mast 20 extends to a considerable height. Again, after removal of the

reinforcing bars, structural steel or cables, the disturbances to the wall caused by so securing the tower mast 20 thereto would be remediated.

The tower mast 20 comprises a support column 22 and a structural column 25 parallel thereto in close, and preferably adjacent, proximity. The platform 40 is movably coupled to the support column 22 and the elevator 30 is movably coupled to the structural column 25, as hereinafter described. Those having ordinary skill in this art will appreciate that conceivably, each of the platform 40 and the elevator 30 could be movably coupled to a different side or face of a common column.

The support column 22 and structural column 25 are commonly connected to the base portion 10. While each column 22, 25 is of substantially a similar height, preferably, the support column 22 is wider and deeper than the structural column 25.

The structural column 25 is conventionally secured and bolted to the support column 22 at various points therealong using outriggers, such as beams or plates, so as to provide additional mutual structural integrity.

Each of the support column 22 and structural column 25 are composed of multiple metal box-type lattice sections bolted together in an end to end configuration along the tower axis 21. A greater or smaller number of sections could be joined together to make up a desired height, commensurate with the application to which the system is to be applied. As is known in the art, objects, such as, in the present invention, the platform 40, may be adapted to climb such columns by selectively engaging with and disengaging from horizontal braces of such lattice sections using selectively engageable extendable hooks.

The construction elevator 30 is a conventional construction elevator, such as is well known in the art, coupled to the structural column 25, so as to move vertically therealong, to deliver personnel and supplies to the platform 40 from a loading area, whether at the ground level of the blast furnace 2, from the top 3 of the blast furnace 2, or some intermediate point, as appropriate, and vice versa.

The construction elevator 30 has a generally planar floor surface (not shown) and side and end panels which substantially surround and enclose the floor surface. Preferably, the construction elevator 30 has a roof to protect occupants from falling debris. The floor, side, end and roof panels may be of wire lattice material to provide visibility from within the elevator 30.

The construction elevator 30 may be constrained to travel only between the loading point, and the level of the platform 40, such as by an end of range detector (not shown) as is well known in this art, or if desired, may be free to assume a position along the tower mast 20 outside of this range.

The construction elevator 30 may be driven by a continuous screw or worm gear mechanism (not shown) attached to the structural column 25, such as is well known to those having ordinary skill in this art.

Turning now to Figure 2, the platform 40 comprises a structural assembly 210, a decking frame 220, a secured deck 230, an elevating unit 240 and an elevator enclosure 250. It supports thereon personnel and materials involved with the construction, repair or demolition of the interior walls 4 of the blast furnace 2.

The structural assembly 210 serves as the base for the platform 40 and is comprised of a plurality of metal beams welded or bolted together to form a substantially rectangular structure that is bolted to the elevating unit 240.

The structural assembly 210 defines an opening 211 in the platform 40, which is coaxial with the central axis 21 of the tower mast 20 and which is sized to accommodate both the tower mast 20 and construction elevator 30 without impediment.

The opening 211 allows the construction elevator 30 to pass unimpeded through the platform 40 either from above or below. In this manner, the platform 40 may remain in working position at a selected elevation, while the construction elevator 30 may- transfer personnel and materials between it and the loading area.

The decking frame 220 is a polygonal annular structure rigidly secured to the structural assembly 210. The decking frame 220 preferably comprises an inner polygonal structure 221 and an outer polygonal structure 222, each comprising a plurality of beams secured end to end and supported by the structural assembly 210. The beams of the inner polygon 221 are shorter than the beams 223 of the outer polygon 222. Corresponding ends of beams of the inner 221 and outer 222 polygons are regular polygons, however, as appropriate, having regard to the cross-section of the interior wall surface 4 to be repaired, the decking frame 220 may assume a substantially elliptical or oblong configuration by employing beams of differing length.

The inner polygon 221 preferably defines the shape and extent of the opening 211.

The diameter of the outer polygon 222 roughly corresponds to the minimum diameter (27 feet, in the exemplary embodiment being described) to which the platform 40 may contract. However, it is slightly smaller, in order to accommodate multiple overlapping sheathing panels 234, and extendable cylinders 231 therefor, as discussed in detail below.

The secured deck 230 comprises a plurality of extendable cylinders 231 extending radially outward from the inner polygon 221 beyond the outer polygon 222 and a plurality of overlapping sheathing panels 234 that cover at least the space therebetween. The secured deck 230 may assume a substantially, elliptical, or oblong, as appropriate, having regard to the cross-section of the interior wall surface 4 to be repaired.

There are at least one and preferably several extendable cylinders 231 for each beam 223 of the outer polygon 222. For example, in the exemplary embodiment shown, there is one cylinder 231 centred beneath each of the two interior panels 235 supported by each beam 223.

The extendable cylinders 231 each comprise a plurality of telescoping cylindrical sections 232 supported by the beams of both the inner 221 and outer 222 polygons. The number of telescoping sections 232 correspond to the number of sheathing panels 234 that extend end to end above a given extendable cylinder 231, and is dependent to some extent on the desired maximum extension of the platform 40. In the exemplary embodiment being described, in which the platform 40 varies in diameter from a minimum of 27 feet to a maximum of 40 feet, the variation in diameter is accommodated by three sheathing panels 234 that extend end to end in their maximum extension configuration, so that three telescoping sections 232 may be adequate.

The first telescoping section 232 (not shown) is provided at each end thereof with a panel mounting bracket 233 (not shown) , which supports a corresponding sheathing panel 234 at each end and enables such panel to be secured thereto.

Subsequent telescoping sections 232 surround, at their interior end, the first section but have a panel mounting bracket 233 at their exterior end, for supporting a corresponding sheathing panel 234 and enabling it to be secured thereto.

The extendable cylinders 231 are selectively extended or contracted in conventional fashion, such as by hydraulics or pneumatics, under operator control, by an extension control device (not shown) , such as would be familiar to those having ordinary skill in this art. Preferably such control device (not shown) is mounted on the platform 40, more preferably proximate to and exterior to the elevator enclosure extension 250.

The sheathing panels 234 are of varying truncated wedge shapes and dimensions. They may be combined together to form a plurality of wedge-shaped sections 237 that extend from the inner polygon 221 to beyond the outer polygon 222, such as is shown by cross-hatched portion 238. Such sections 237 lie side-by-side in slightly overlapping fashion to form a substantially circular platform surrounding the opening 211. Preferably, the number of sections 237 corresponds to the number of beams 223 in the outer polygon 222. Thus, in the exemplary embodiment being described, there are 12 such sections .

Each section 237 is comprised of a plurality of panels 234. In the exemplary embodiment being described, these are a

pair of identical adjacent interior panels 235, a pair of slightly larger identical intermediate panels 236 and a single larger exterior panel 237, although those having ordinary skill in this art will appreciate that other numbers, shapes, sizes, sizes and/or combinations of panels 234 may be adopted.

The length of the arc of the inside end of each intermediate panel 236 is substantially equal to and preferably slightly longer than the length of the arc of the outside end of the interior panel 235, so that the intermediate panels 236 slightly overlap the interior panel 235 corresponding to the same section 237 as well as that of an adjacent section, so that the likelihood of personnel, equipment, tools, hardware, or debris falling through the panel 40 is substantially eliminated, even when the platform 40 is fully extended, for example, to a diameter of a substantially 40 feet, in the exemplary embodiment being described.

Similarly, the length of the arc of the inside end of each exterior panel 237 is substantially equal to and preferably slightly longer than the length of the arc of the outside end of the exterior panel 236, so that the exterior panels 237 slightly overlap the intermediate panel 236 corresponding to the same section 237 as well as that of an adjacent section.

Both the inside and outside ends of the interior panels 235 are secured to corresponding mounting brackets 233 (not shown) at each end of the first telescoping section 232, while the outside ends of each of the intermediate panels 236 and of the exterior panels 237 are secured to corresponding mounting brackets 233 at the exterior end of the telescoping sections 232 telescoping outward therefrom.

Thus, when the extendable cylinders 231 are fully retracted, the exterior panels 237 considerably overlap the intermediate panels 236, which in turn considerably overlap the interior panels 235, to form a relatively compact circular platform 40.

As the extendable cylinders 231 are extended under operator control of the control device (not shown) , to increase the diameter of the platform 40, the exterior panels 237 progressively overlap the intermediate panels 236 by a lesser degree and the intermediate panels 236 progressively overlap the interior panels by a lesser degree, until the extendable cylinders 231 reach their maximum extension and the platform 40 reaches its maximum extension. Manifestly, the extendable cylinders 231 may extend only to a portion of their maximum extension so as to provide a base for the platform 40, that may assume any diameter intermediate its minimum and maximum extension.

The elevating unit 240, to which the structural assembly 210 and by extension the decking frame 220 and the secured deck 230 is secured, is a C-shaped structure mounted over and around the support column 22 of the tower mast 20, and is movably coupled thereto, the elevating unit 240 being sized so as to accommodate therewith the support column 22.

The elevating unit 240 is in turn coupled to the support column 22 by a conventional lifting hook mechanism known to those having ordinary skill in the art. Such mechanisms typically have a series of preferably at least two extendable vertical hooks (not shown) extending from the elevating unit 240, that may be engaged, disengaged, extended and retracted under operator control of an elevation control device (not

shown) . Again, preferably, such elevation control device (not shown) is mounted on the platform 40, more preferably proximate to and exterior to the elevator enclosure 250 and still more preferably proximate to or adjacent to the extension control device (not shown) . Each of these hooks engages a successive one of the horizontal braces on the lattice structure of the support column 22.

To raise the platform 40, the hook (not shown) that is engaging the bottommost brace is disengaged therefrom, extended to the level of the horizontal brace above the uppermost brace already engaged by a hook and all of the hooks are retracted to move the platform 40 upward by the distance between successive horizontal braces and the process is repeated.

To lower the platform 40, the hook (not shown) that is engaging the uppermost brace is disengaged therefrom, retracted to the level of the horizontal brace below the bottommost brace already engaged by a hook and engaged thereto, while the other hooks are correspondingly extended. Then the process is repeated.

Vertical movement of the elevating unit 240 and of the platform 40 along the length of the support column 22 is unhampered by, and independent of, any vertical movement of the construction elevator 30 along the length of the structural column 25.

The elevating unit 240 comprises a plurality of guides 241, which extend at least partially across the open face of the elevating unit 240 so as to partially enclose the support column 22 therein, and substantially inhibit the elevating unit 240

from disengagement from the support column 22, the guides 241 being slightly clear of the support column 22.

The elevator enclosure 250 comprises a plurality of panels 251, 252 that enclose a portion of the opening 211. The panels 251, 252, which may be detachable, are interconnected and secured to one another and to the platform 40 to surround a portion of the opening 211 and form a cage or safety enclosure around the elevator 30 when it is at platform level, to prevent or substantially inhibit personnel and/or materials from inadvertently falling through the opening 211 when the construction elevator 30 is not at platform level.

At least one panel 251 is an entrance panel and positioned so as to provide a closable means of access to the construction elevator 30, whereby personnel and/or materials may be loaded and unloaded by. In the exemplary embodiment shown, there are two such entrance panels 251.

The entrance panel (s) 251 may be conventional guillotine- style door panels which can be opened and closed vertically, although other suitable door configurations may be suitable.

Preferably, the panels 251, 252 are covered with wire mesh or chain link, so as to permit visibility through the enclosure 250 from outside or inside the construct elevator 30. Preferably, that portion of the opening 211 that is not surrounded by the enclosure 250 may be covered by a floor 253, which is shown in cut-away fashion in Figure 2.

In operation, the platform 40 is driven by the hydraulically activated series of hooks along the support column 22 of the tower mast 20 to a selected desired working elevation within the interior of the blast furnace 2, and the perimeter of

the platform 40 is expanded or contracted to provide access therefrom to all of the interior wall surface furnace 4 at the selected working elevation.

The elevator 30 may be driven by the continuous screw or worm gear assembly along the structural column 25 of the tower mast 20. As it approaches platform level, it is matingly received within the opening 211 in the platform 40, whereby personnel and materials can be passed through the enclosure 250 and onto the platform 40 at the selected working elevation.

Personnel and/or materials may be loaded and unloaded from either through the furnace top opening 3 or through the blast furnace 2 at the tuyere or ground level or at some point intermediate thereto.

In this manner, and unlike conventional systems and arrangements, the present invention provides an innovative elevatable mast climbing work platform system 1 for use in blast furnace repair which enables a transport elevator carrying materials and/or personnel to travel to or from a work platform 40 at a selected elevation where the work is taking place to a loading area 40, without substantially moving the work platform from the selected elevation. Further, the present invention provides a substantially circular, elevatable working platform having an adjustable diameter that is able to quickly conform to and substantially accommodate variances in the width of interior walls 4 the blast furnace 2 along its vertical extent.

Additionally, and unlike conventional systems, there is no repositioning of the system 1 around the blast furnace 2 in order to access each part of the vertical wall 4 thereof at the same element is substantially avoided.

The system 1 may be at least partially assembled outside the blast furnace 2, with final assembly of all components taking place inside the blast furnace 2.

Further, the base portion 10, the tower mast 20, the elevator 30 and, the platform 40, may be disassembled for economical and efficient transport in component form for later assembly.

It will be apparent to those skilled in this art that various modifications and variations may be made to the embodiments disclosed herein, consistent with the present invention, without departing from the spirit and scope of the present invention.

Other embodiments consistent with the present invention will become apparent from consideration of the specification and the practice of the invention disclosed therein.

Accordingly, the specification and the embodiments are to be considered exemplary only, with a true scope and spirit of the invention being disclosed by the following claims.