Patent Application
20180328021
The disclosure relates generally to covers for large open-top municipal and industrial reservoirs, and more particularly it pertains to symmetrical basin covers mountable to unequally-spaced anchor retention areas.
Covers for large municipal and industrial reservoirs or basins that are of interest herein are described and illustrated in the following documents:
The basins of interest herein are rectangular open-top municipal and industrial tanks, reservoirs or basins that are used for clarification of wastewater for example. Covers are used on these basins to reduce the ingress of rainwater and snow inside the basins; to block sunlight and control algae growth or to collect bio-gases released from the content of these basins. Covers for these basins are typically made of a flexible impermeable fabric sheet, stretched and supported on an array of spaced-apart arches. These arches are anchored to the rim of the basins. For aesthetic reasons and design considerations, these arches are evenly spaced and parallel to each other along the basin.
Some basins have narrow walkways there-around, and anchoring a new cover to these basins using traditional techniques reduces the width of these walkways to a dimension that is no longer acceptable by safety standards. In other examples, basins are often made of concrete, and the concrete of the walkways still contains embedded sockets, beam stubs and similar vestiges of an old cover. Because of these remains of an anterior construction, it becomes a challenge to support a new cover with precision and symmetry over such a basin. Improvement is desirable.
In one aspect, the disclosure describes a basin that has unevenly-spaced anchor retention areas along the rim thereof and a cover than has evenly-spaced covering elements mounted to one or more shelf angle. The shelf angle is attached to the vertical portion of the rim of the basin. A series of flat tabs are affixed to the horizontal portion of the shelf angle. These flat tabs extend over the horizontal portion of the rim of the basin and are anchored to the horizontal portion of the rim of the basin. Each flat tab is positioned along the shelf angle in such a way as to overlap one of the unevenly-spaced anchor retention areas, and to be anchored to that anchor retention area. The cover can be installed to basins of different conditions without major custom work.
In another aspect, the disclosure describes a basin having a rim comprising opposite vertical edge surfaces and horizontal edge surfaces respectively contiguous with one of the vertical edge surfaces, and a cover mounted thereon. The cover comprises a plurality of spaced-apart arches mounted to a pair of shelf angles. These shelf angles are affixed to the rim of the basin. Each of the shelf angles has a web portion extending parallel with, and against one of the vertical edge surfaces of the rim of the basin, and a flange portion extending horizontally away from the vertical edge surface. The cover also has a plurality of flat tabs attached to the flange portion of the shelf angles at adjustably-spaced intervals. The flat tabs extend over the horizontal edge surfaces of the rim of the basin for retaining each shelf angle to the rim of the basin. The flat tabs retain the shelf angles and the arches of the cover to the rim of the basin. The shelf angles in cooperation with the flat tabs resist wind uplift forces and downward loading on the cover.
Although the rim of the basin may comprise limited anchor retention areas, the flat tabs are adjustable to overlap the anchor retention areas so that a standard cover can be mounted to a nonstandard basin.
The shelf angles are installed with the flange portion of the shelf angles extending in a same plane as the horizontal edge surfaces of the rim of the basin for widening this horizontal edge surfaces and create space for mounting the cover. When a walkway is associated with these horizontal edge surfaces, the shelf angles add to the width of this walkway, for widening this walkway.
Embodiments may include combinations of the above features.
This brief summary has been provided so that the nature of the invention may be understood quickly. Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description included below and the drawings.
Reference is now made to the accompanying drawings, in which:
Aspects of various embodiments are described through reference to the drawings.
Referring firstly to
As can be appreciated from
The arches 22 are evenly spaced along a pair of supporting shelf angles 30 as can be seen in
The expression “shelf angle” is used herein to designate a structural angle that is mounted as a shelf to a vertical wall. The portion of that structural angle extending along the wall is referred to as the web portion, and the portion extending as a shelf is referred to as the flange portion, for convenience.
Referring now to
The shelf angles 30 support the cover to the rim of the basin 20. Each shelf angle has a web portion 40 extending vertically along the vertical edge surface 42 of the basin, and a flange portion 44 extending in an overhang mode toward the center of the basin. The flange portion 44 is preferably mounted flush with the top surface of the walkway 26 so as to widen the existing walkway 26.
The cover 20 according to the preferred embodiment also has randomly spaced flat tabs 50 bolted to the shelf angle 30 and extending in opposite direction from the flange portion 44 of the shelf angle 30. In use, the tabs 50 extend over the walkway 26 and contribute to support the shelf angles 30 to the perimeter of the basin.
The tabs 50 are spaced apart unequal distances “A” and “B” as indicated in
Referring now to
It will be appreciated that the sound concrete anchor retention areas 70 to which a cover may be anchored between the obstacles mentioned above are unevenly-spaced along the walkway 26. In order to overcome this inconvenience, the tabs 50 along the shelf angle 30 can be installed in an uneven spacings as required along the shelf angle 30 to correspond to the spacings “A” and “B” between the anchor retention areas 70 along the walkway 26. The flat tabs 50 are adjustably mountable along the shelf angle 30 by drilling holes through the flange portion 44 of the shelf angle 30 and bolting the tabs 50 to the flange portion.
Because of the shelf angles 30 and the adjustable tabs 50, it will be appreciated that a standard cover can be mounted to an old basin with limited custom work.
In the cover 20 according to the preferred embodiment, the flexible sheet 24 is tightened across the arches 22 by a series of tighteners 32 that are also mounted to the shelf angles 30 through bolts. These tighteners act on a pipe mounted in a hem along the bottom edge of the flexible sheet.
Referring now to
Again in
As can be understood, a first series of anchor bolts 82 are mounted at right angle with a second series of anchor bolts 84. The horizontal and vertical anchor bolts 82 and 84 preferably enclose a reinforcing bar 86, when a location of such bar is known.
Therefore the structure at both ends of the arches 22 are supported to the basin against horizontal and vertical stresses as well as against torsional moment along the shelf angles. Furthermore, the preferred shelf angle 30 may optionally have spaced-apart gussets 88 thereon to prevent a deflection in the shelf angle in use.
The above description is meant to be exemplary only, and one skilled in the relevant art will recognize, that changes may be made to the embodiments described without departing from the scope of the invention disclosed. The present disclosure may be embodied in other specific form without departing from the subject matter of the claims. The present disclosure is intended to cover and embrace all suitable changes in technology. Modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims. Also, the scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.
