Patent Application
20070001475
The present invention relates to retractable canvas structures, and more specifically to retractable cover apparatus for an open-topped container such as a truck or trailer bed.
In many jurisdictions, the law requires that trucks and trailers used in the transport of various materials such as sand, gravel, grain, trash or other loose substances have a cargo area fully covered by a tarpaulin sheet or a net in order to prevent transported material to be blown away and cause a driving hazard for following vehicles or dump litter on the highway.
An example of retractable cover mechanism is disclosed in U.S. Pat. No. 6,435,595 Chenowth, which patent is incorporated in its entirety in this specification by this reference.
It has been found that when the parallel beams or bows that span the cargo area and to which the covering sheet is attached at regularly spaced intervals are contracted toward one another while they are being retracted toward the front or back of the cargo compartment, the strips of covering materials between the bows tend to bunch up randomly into odd shapes that sometimes interfere with the orderly and total withdrawal of the cover, or get caught in the withdrawing mechanism.
A prior attempt to avoid these problems is illustrated in
The instant invention results from an attempt to devise a more practical and less costly mechanism for guiding the withdrawal of a cargo cover into orderly and compact corrugations, and to allow a complete and flat deployment of the cover.
One or more series of flexible and arcuate strips are secured between the ends of the framing beams or bows that span a truck cargo area and to which a tarpaulin cover sheet is attached. Each strip is pre-bended to form when contracted by the retracting movement of the bows one or two arches that vault upwardly or horizontally outwardly in order to guide the edges of the cover sheet into regular corrugations of valley and ridges that compact in an orderly manner between the retracting bows, and are kept away from any retracting cables, pulleys, or other parts of the cover deploying and retracting mechanism.
In some embodiments, it is provided that in a covering system wherein a pliable sheet is retracted from a deployed position to a folded position by contracting a series of parallel attachment bars spanning the sheet at spaced-apart locations perpendicularly to the direction of retraction, an improvement to force the sheet into orderly corrugations, said improvement comprising a plurality of flexible strips interposed between said bars. Some embodiments further comprise means for securing opposite ends of said strips to said bars. Some embodiments further comprise a cable running along a side of said sheet, said cable being slidingly connected to median portions of said strips. In some embodiments a first series of said strips are biased to flex into substantially vertical arches. In some embodiments a second series of said strips are biaseded to flex into substantially horizontal arches. In some embodiments the strips are biased to flex into an oblique direction. Some embodiments further comprise a second series of said strips which are biased to flex into substantially horizontal arches. Some embodiments further comprise a first series of said strips oriented to flex into substantially vertical arches. Some embodiments further comprise a second series of said strips oriented to flex into substantially horizontal arches. Some embodiments further comprise said strips being oriented to flex in an oblique direction. In some embodiments a second series of said strips are oriented to flex into substantially horizontal arches.
In some embodiments there is provided a mechanism for retracting a sheet from a deployed position along a folding direction, which comprises a series of attachment bars spanning and secured to said sheet at spaced-apart intervals; and, a plurality of flexible strips interposed between said bars. Some embodiments further comprise means for securing opposite ends of said strips to said bars. Some embodiments further comprise a cable running along a side of said sheet, said cable being slidingly connected to median portions of said strips. In some embodiments a first series of said strips are biased to flex into substantially vertical arches. In some embodiments the strips are biased to flex into an oblique direction. Some embodiments further comprise a second series of said strips being biased to flex into substantially horizontal arches. Some embodiments further comprise a second series of said strips being biased to flex into substantially horizontal arches. Some embodiments further comprise a cable running along a side of said sheet, said cable being slidingly connected to median portions of said strips. In some embodiments a first series of said strips are biased to flex into substantially vertical arches. In some embodiments a second series of said strips are biased to flex into substantially horizontal arches. In some embodiments said strips are biased to flex into an oblique direction. Some embodiments further comprise means for securing opposite ends of said strips to said bars. In some embodiments each of said strips is permanently creased in a common direction proximate opposite extremities. In some embodiments each of said strips is permanently creased in a first direction about a median line.
In some embodiments there is provided a mechanism for retracting a sheet covering a truck bed along a folding direction from deployed position to a corrugatedly folded position, which comprises: a series of attachment bows spanning said truck bed at spaced-apart intervals perpendicularly to said folding direction; a first series of arcuate, flexible strips secured between the ends of adjacent ones of said bows, and oriented to vault upwardly when said bows are contracted toward one another; a second series of gullwing-shaped, flexible strips; a pair of wires running parallely along lateral edges of said sheet, and being slidingly connected to a median portion of each of said gullwing-shaped strips, said gullwing-shaped strips being oriented to form a pair of arches projecting outwardly and substantially horizontally when said bows are contracted toward one another. In some embodiments the second series of flexible strips are secured at opposite extremities to said ends.
In some embodiments there is provided a method for installing an orderly corrugator in a cargo covering system wherein a pliable sheet is retracted from a deployed position to a folded position by contracting a series of parallel attachment bars spanning the sheet at spaced-apart locations perpendicularly to the direction of retraction, wherein said method comprises: deploying said sheet to form a spacing between a first and second of said bars; securing a first portion of a continuous flexible ribbon to a first of said bars; selecting a second portion of said ribbon spaced a distance apart from said first portion, wherein said distance is greater than said spacing; and securing said second portion to said second of said bars. In some embodiments the method further comprises; slidingly connecting a median portion of said ribbon to a cable running along a side of said sheet; wherein said median portion is located between said first and second portions. Some embodiments further comprise; forming a pair of arcuate arches straddling said median portion and between said first and second portions.
Referring now to the drawing, there is shown in
A first series of flexible strips 20 is interposed between the bows. Each strip has its opposite extremities 21, 22 secured by screws to a pair of adjacent bows. The strip is permanently creased 38, 39 in a common direction proximate both extremities, and retains a slight arcuate shape along a broad radius when the cover sheet is fully deployed. The combination of the creases and the orientation of the attachments to the bows bias the strip into a predetermined bending direction. More specifically, as the two bows 13 and 14 are brought together, the strip 20 flexes and vaults upwardly to form an arch 23 as illustrated in
A second series of flexible strips 24 are also interposed between the bows 13, 14. They are secured at their opposite extremities to vertical edges 25 of the bows' ends. These second type of strips are biased by being given a permanent gullwing shape by a permanent crease or fold 26 in a median section and oppositely directed creases 27 near their extremities. The strips 24 are also slidingly connected to the withdrawing cable 19 through two eyelets 28 punched in the median section astride the median line and central fold 26. Due to their orientation and biasing, this second series of strips tend to form two outwardly and horizontally extending bulges which form arches 32,33 as the bows are brought together during the cover withdrawing movement, as shown in
As illustrated in
An alternate arrangement of two series of flexible strips 30,31 is illustrated in
The cable 19 upon which the strips are slidingly engaged may be the one secured to the first bow that controls the deployment and withdrawal of the cover, or may be an additional pair of static cables or rods.
As illustrated in
The embodiments of
While the preferred embodiment of the invention has been described, modifications can be made and other embodiments may be devised without departing from the spirit of the invention and the scope of the appended claims.
