Tarp cover system with support bow configuration for reducing stress on tarp material

A system may include a container and a cover apparatus for selectively covering a top opening of the container. The cover apparatus may include a roll tube movably mounted on the container and extending between the container ends and parallel to the container sides, a cover tarp having at least a portion rolled about the roll tube, and at least one bow member configured to support the cover tarp over the top opening in a closed condition of the cover assembly. The bow member may be elongated and extend from one said side of the container to the other said side of the container across the top opening of the container. The bow members may be positioned in a substantially vertically-oriented bow plane, and the bow plane may be oriented at an oblique angle to a sidewall plane of the container.

BACKGROUND

Field

The present disclosure relates to covering systems for containers and more particularly pertains to a new tarp cover system with support bow configuration for reducing stress on tarp material.

SUMMARY

In one aspect, the present disclosure relates to a system which may comprise a container having a top opening, opposite sides and opposite ends. The container may have a pair of spaced side walls and a pair of spaced end walls extending between the side walls, with at least one of the side walls defining a sidewall plane. The system may also comprise a cover apparatus for selectively covering the top opening of a container, with the cover apparatus having a closed condition closing the top opening and an open condition permitting access to the top opening. The cover apparatus may include a roll tube movably mounted on the container and extending generally between the ends of the container and being oriented generally parallel to the side walls of the container. The cover apparatus may also include a cover tarp having at least a portion rolled about the roll tube. The cover tarp may be substantially completely unrolled from the roll tube and be extended across the top opening when the cover apparatus is in the closed condition, and may be substantially completely rolled about the roll tube and be retracted to one of the sides of the container when the cover apparatus is in the open condition. The cover apparatus may include at least one bow member configured to support the cover tarp in the closed condition of the cover assembly, with the bow member being elongated and extending from one said side of the container to the other said side of the container across the top opening of the container. The bow member may be positioned in a substantially vertically-oriented bow plane, and the bow plane may be oriented at an oblique angle to the sidewall plane of the container.

DETAILED DESCRIPTION

With reference now to the drawings, and in particular toFIGS. 1 through 6thereof, a new tarp cover system with support bow configuration for reducing stress on tarp material embodying the principles and concepts of the disclosed subject matter will be described.

Tarps have been used for covering the open tops of containers, and are often rolled to one side of the container to “open” or expose the open top of the container and unrolled over the open top to “close” or cover the open top (see, e.g.,FIGS. 1 and 2). Typically the tarp is supported in the unrolled, closed condition by a series of support bows that extend from one side of the container to the opposite side of the container, and in many instances the bows have a slight upward “bow” or curvature that produces a slight peak in the closed tarp cover between the opposite sides. Usually the support bows are mounted on the long sides of the container and are generally uniformly spaced from and between the opposite ends of the container. The support bows extend between the container sides in a vertical plane that is perpendicular to the walls forming the sides of the container as well as the upper edges of those side walls.

The material of the tarp is wrapped or coiled about a strong roll tube which extends between the ends of the container and supports the portions of the tarp material located between the support bows as the roll tube rolls across the spaced bows and the tarp is unrolled from the tube (see e.g.,FIG. 3) until the tarp assumes the closed condition of the cover (and also as the uncoiled tarp and roll tube roll across the spaced bows to re-coil the tarp onto the tube until the tarp assumes the open position of the cover).

The applicants have recognized that the conventional configuration of a tarp cover system tends to stress the tarp material along distinct lines that correspond to the locations of the support bows. More specifically, during times when the tarp material is being unrolled (or rolled up) across the support bows, areas of the material are being compressed or pinched between the roll tube from above and the support bow from below. This pinching action is concentrated on only the areas of the tarp material which are located above the support bows (when unrolled), and not the areas of the tarp located between the support bows (when unrolled), as these are the areas that end up between the roll tube and the support bows. The pinching stress thus generally occurs along lines on the tarp material located above the support bow. The broken lines inFIG. 3illustrate the lines of contact between the tarp material and the support bows, and how the line of contact of the tarp portion which is coiled about the roll tube remains aligned with the support bow and thus continues to be pinched as rolling or unrolling of the tarp material continues. This repeated concentrated pinching of the tarp material tends to weaken the tarp material along the lines and shorten the life of the tarp in these areas as compared to other areas of the tarp.

Even more significantly, areas of the tarp located closer to the attachment of the tarp material to the roll tube (e.g., the innermost coils) are subjected to the pinching more often than areas of the tarp on the outermost coils. For example, if the roll tube rotates 20 times between the rolled and unrolled condition of the tarp material, the area of the tarp material located in one of the innermost coils will be pinched 20 times during each coil/uncoil cycle for the tarp between the open and closed conditions, while an area of the tarp material located on one of the outermost coils may only be pinched once or twice during each coil/uncoil cycle.

The problems caused by such pinching can be exacerbated by installations in which one or more support bows are higher or taller than adjacent support bows, due to, for example, manufacturing variations or simply variations in the manner in which the bows are installed. The higher bows tend to carry relatively more of the weight of the tarp material and roll tube than the relatively lower adjacent bows, and as a result the tarp material positioned above the higher support bow is subjected to even greater pinching forces.

The applicants have recognized that a primary contributor to the repeated pinching of the same areas of the tarp material on the line along the bow support is the perpendicular orientation of the support bow with respect to the side walls of the container. Since the support bows extend generally parallel to the direction of movement of the cover as the tarp material is rolled or unrolled, the same areas of the tarp material are subject to repeated pinching force.

The applicants also recognized that a highly effective approach for distributing the pinching force on the tarp material (so that a particular point on the tarp may only be subjected to the pinching effect once each time the tarp is either rolled or unrolled), is to position or orient the support bow generally along a line that is skewed with respect to the direction of movement of the rolling or unrolling of the tarp material, and generally not parallel to the direction of movement. The support bow may be positioned in a bow plane that is not oriented perpendicular (or substantially perpendicular) to the side of the container. Such an orientation of the support bow orients the line of the pitching pressure so that a particular point is only pinched once during a coil/uncoil cycle and not subject to repeated compressions between the roll tube and the support bow. Notably, the support bows do not need to be oriented parallel to each other to achieve this benefit, merely need to be oriented obliquely to the direction in which the tarp material unrolls from or rolls onto the roll tube.

In one aspect of the disclosure, the system1includes a container10which has an open top and generally closed sides and bottom. The container10may comprise a hopper and may be mounted on a suitable vehicle, such as, for example, a truck, a trailer, or even a rail car chassis. The open top of the container10may form a top opening12. The top opening12may lie in an opening plane13which may be generally horizontally oriented. The top opening12may be defined by an upper perimeter edge14of the container which may also lie in the opening plane. The container10may have opposite sides16,17and opposite ends18,19. The container may comprise a pair of side walls20,21positioned at the opposite sides16,17, and end walls22,23which are positioned at the opposite ends18,19. At least one of the side walls20,21may lie in a side wall plane11which is oriented substantially perpendicular to the opening plane13, and the sidewall plane may also be oriented substantially vertical. Each of the side walls20,21may form a side portion24,25of the upper perimeter edge14, and each of the end walls20,23may form an end portion26,27of the perimeter edge14.

The system1may also include a cover apparatus30which is configured to selectively cover the top opening12of the container, and may be moved between a closed condition in which the apparatus30closes the top opening and an open condition which permits access to the interior of the container through the top opening. The cover apparatus30may include a roll tube32which extends generally between the opposite ends18,19of the container, and may have a first end34which is positioned adjacent to the end18of the container, and a second end35which may be positioned adjacent to the end19of the container. The roll tube32may be oriented generally parallel to one or both of the side walls20,21of the container and perpendicular to the container end walls22,23. The roll tube may be positioned at one of the sides16in the open condition and at the other side17in the closed condition.

The cover apparatus30may also include a cover tarp40which is positionable over the top opening12of the container10, and may have at least a portion which is wrapped or coiled about the roll tube32. The cover tarp40may have an inboard edge portion42which may be secured to the roll tube, and also an outboard edge portion44which may be secured to one of the sides or side walls of the container. When the cover apparatus30is in the closed condition, the cover tarp40may be substantially completely unrolled from the roll tube32and be extended across the top opening12of the container. When the cover apparatus30is in the open condition, the cover tarp40may be substantially completely wrapped or coiled about the roll tube32and may be retracted to one of the sides of the container. The cover tarp40may comprise a flexible sheet of material.

The cover apparatus30may also include a motor assembly50which is configured to rotate the roll tube32to spool and unspool, or wind and unwind, the cover tarp40on and off of the roll tube. The motor assembly may be positioned at one of the ends34,35of the roll tube and thus may be located toward one of the ends18,19of the container.

The cover apparatus30may also include at least one arm assembly56which is configured to support the roll tube32on the container. Typically, a pair of arm assemblies56,58may be employed with one of the arm assemblies being located at each end of the roll tube. Each of the arm assemblies56,58may be mounted on one of the opposite ends18,19of the container. Each of the ends34,35of the roll tube32may be rotatably mounted on a respective one of the arm assemblies56,58. Suitable arm assemblies are disclosed, for example, in U.S. Pat. No. 9,283,832, which is hereby incorporated herein by reference in its entirety. The motor assembly50may be mounted on one of the arm assemblies to rotate the roll tube with respect to the arm assembly.

The cover apparatus30may also include at least one bow member60which is configured to support the cover tarp40when the cover apparatus is in the closed condition, or moving from the open condition toward the closed condition. While one bow member may be utilized in a cover apparatus, in some embodiments a plurality of bow members60,62may be employed to support the tarp40, and the bow members may be substantially uniformly spaced between the end walls22,23of the container. Each of the bow members may be positioned across the top opening12of the container to bridge between the opposite side walls20,21. Each bow member may be elongated and extend from one side wall the container to the other opposite side wall of the container. Each of the bow members60,62may have opposite ends64,65and may be arced or arched between the opposite ends in an upward direction out of the opening plane. The apparatus30may also include a bow mounting bracket66which is configured to mount one of the ends64,65on the container. The bow mount bracket66may be mounted on one of the side walls20,21of the container, and may be located toward the upper perimeter edge14of the container.

Each of the bow members may be positioned in a bow plane68which may be substantially vertically oriented, and thus substantially perpendicular to the opening plane of the container. A perpendicular reference plane70may be may also be substantially vertically oriented and may be oriented substantially perpendicular to the side wall plane11.

Significantly, the bow plane68may be oriented in a non-perpendicular relationship with respect to the sidewall plane11. The bow plane68may be oriented at an oblique angle with respect to the side wall plane, and may form an angle (α) with the perpendicular reference plane. The measure of the angle (α) between the bow plane68and the perpendicular reference plane70may have a range between approximately 1 degree and approximately 10 degrees. In some embodiments, the angle (α) may measure from approximately 3 degrees to approximately 7 degrees. In some further embodiments, the angle (α) may measure approximately 5 degrees.

The broken lines inFIG. 5illustrate the lines of contact between the tarp material of the cover tarp and the non-perpendicular oriented support bows.FIG. 5also illustrates how the line of contact on the coiled portion of the cover tarp does not continue to align with the support bow as the tarp material is coiled or rolled onto the roll tube. As a result, the material at a point along the line of contact is not repeatedly compressed or pinched as illustrated inFIG. 3showing a conventional design, but instead is only pinched a single time at each rolling or unrolling of the tarp material.

It should be appreciated that in the foregoing description and appended claims, that the terms “substantially” and “approximately,” when used to modify another term, mean “for the most part” or “being largely but not wholly or completely that which is specified” by the modified term.

It should also be appreciated from the foregoing description that, except when mutually exclusive, the features of the various embodiments described herein may be combined with features of other embodiments as desired while remaining within the intended scope of the disclosure.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated.