Patent Application
20140034771
The present invention relates to a method and apparatus for positioning a tarpaulin over a load on a flatbed trailer to protect and secure the load.
Flatbed trailers are commonly used to transport cargo, such as lumber, other construction materials, manufactured components, containers, boxes, and other freight. In order to protect the cargo while it is loaded on the flatbed, it is common to cover the load with a tarpaulin, also referred to herein as a tarp. The tarp serves to protect the cargo from environmental elements, such as dirt, precipitation, sunlight, and wind. Additionally, the tarp serves to secure the cargo on the flatbed such that it will not blow away, and such that it is not easily stolen off the trailer when the trailer is parked.
Positioning the tarp onto the cargo can be a cumbersome job. The difficultly of the job can be exacerbated when the cargo results in an uneven load of varying heights. The most common method for positioning a tarp on such an uneven load is to have one or more workers climb on top of the load and position the tarp as they unfold it across the load. However, due to the height of the load above the ground, and the potentially unstable and uneven surface on top of the cargo load, this can be dangerous. It is also known to build elevated structures such as a u-shaped walkway or dock that a flatbed trailer can be positioned adjacent to in order to permit workers to position a tarp on top of a loaded flatbed trailer without climbing onto the load itself. These structures have the disadvantage of representing a fairly significant initial capital expense, as well as being stationary structures that occupy significant space.
U.S. Pat. No. 7,314,244 describes a method and apparatus for positioning a tarp over cargo on a flatbed using a lifting device, such as a forklift, with a flat frame extending laterally from the forklift. In use, a worker completely unfolds a tarp and positions it on the flat frame. The flat frame is then elevated by the forklift above the load, and as the forklift is driven longitudinally along the side of the loaded flatbed, the unfolded tarp is pulled off the flat frame and positioned on the load. This represents an improvement over the manual methods described above, but is cumbersome and inefficient in requiring the tarp to be unfolded by a worker prior to being positioned on the load.
Thus, there is a need for an apparatus and method for positioning a tarp on cargo loaded on a flatbed. Preferably, the method and apparatus should avoid the need for a worker to climb on top of the load in order to position the tarp. Furthermore, it would be desirable to avoid the need for permanent elevated structures that consume significant amounts of space, such as elevated loading docks. Preferably, the method and apparatus will not require a worker to completely, or nearly completely, unfold the tarp prior to positioning the tarp on top of the load.
According to one embodiment, the present invention is a tarp deploying apparatus that includes a frame assembly with attachment structure for connecting the frame assembly to a lifting device. A roller assembly extends generally laterally from the frame assembly. The roller assembly includes a roller body adapted to have a tarp rolled upon it. The roller body may have a plurality of hooks on it for engagement with openings in a tarp. Each of the hooks may be shaped such that when the roller body is oriented such that a distal end of the hooks extend generally upwardly, the hooks will retain a free end of the tarp such that it can be rolled on to the roller body by rotating the roller body in a first direction. Each of the hooks may be shaped such that when the roller body is oriented such that the distal ends of the hooks extend generally downwardly, the hooks will permit the tarp to fall off of the hooks as the roller body rotates in a second direction opposite from the first direction. The roller assembly may include a spindle that is cantilever mounted to the frame assembly with the roller body mounted to the spindle for rotation about the spindle. The roller assembly may also include a handle operably connected to the roller body whereby rotation of the handle causes corresponding rotation of the roller body. The tarp deploying apparatus may include a brake member that resists rotation of the roller body. The brake member may be a resilient flap mounted to the frame assembly. The roller assembly may include a handle operably connected to the roller body for rotation with the roller body, the handle including a plurality of spokes. The resilient flap may extend from the frame assembly towards the handle such that a free end of the flap is in alignment with the plurality of spokes whereby rotation of the roller body causes the spokes to periodically contact the free end of the flap when the roller body rotates. A counterbalance weight may be provided on the frame assembly.
According to another embodiment, the present invention is directed to a method of deploying a tarp onto cargo loaded on a flatbed trailer. A tarp deploying apparatus that has a frame assembly and a roller assembly including a roller body with a tarp rolled upon it is attached to a forklift. The forklift is positioned at a first end of the flatbed trailer with the roller body positioned generally above an upper surface of the cargo. A portion of the tarp is partially unrolled off of the roller body such that a first portion of the tarp is in contact with the cargo or the flatbed trailer. The forklift is moved alongside the flatbed trailer toward a second end of the flatbed trailer with the roller body raised above the upper surface of the cargo whereby resistance caused by the first portion of the tarp in contact with the cargo or the flatbed trailer causes the tarp to unroll off of the roller body onto the cargo. A tarp maybe rolled on to the roller by engaging eyelets on the tarp to a plurality of hooks the roller body and rotating a handle operably connected to the roller body. The forklift may be moved along the flatbed trailer until the tarp falls off of the hooks. The roller body may be maintained at a desired distance above the upper surface of the cargo by raising and lowering the roller body as the forklift is moving alongside the flatbed trailer.
A handle may be provided in operable connection to the roller body for rotation with the roller body. A resilient flap may extend from the frame assembly towards the handle such that rotation of the roller is resisted by the handle periodically contacting the resilient flap.
According to yet another embodiment, the present invention is directed to a tarp deploying apparatus that includes a frame assembly with a top plate having an upper surface and a lower surface, the top plate further having first and second lateral edges spaced apart from and generally parallel to each other. Attachment structures adapted for receiving tines from a forklift are provided on the lower surface. A support structure supports the top plate above ground level. A spindle is mount to the top surface and extends laterally beyond the first lateral edge of the top surface. A roller body is mounted to the spindle for free rotation about the spindle. A plurality of hooks in alignment with each other is provided along the roller body. A handle structure is operably connected to the roller body for rotation with the roller body. The spindle may be an elongated shaft. The roller body may be a cylindrical tube, and at least one set of ball bearings may be provided between the spindle and the roller body. A brake for slowing rotation of the roller body around the spindle may include a resilient flap that periodically contacts the handle as the roller body rotates around the spindle. A counterbalance weight may be provided on the frame assembly near the second lateral edge of the top plate.
The attached drawings show a preferred embodiment of a new apparatus and method for positioning a tarp on a loaded flatbed trailer. As can be seen in the drawings and the following description, the apparatus includes a frame that is suitable to be attached to a lifting device, such as a forklift. A roller extends laterally from the frame. The roller is suitable to have a folded tarp rolled around and carried on the roller. In order to position the tarp on the loaded flatbed trailer, the forklift is driven longitudinally along the side of the loaded flatbed trailer with the forklift used to raise and lower the roller so that it is positioned a small distance above the load. As the forklift drives along the side of the flatbed trailer, the tarp unrolls off the roller into position on top of the load. Therefore, there is no need for substantial permanent structure, for any users to climb on top of a load, or for a user to completely unfold the tarp prior to positioning the tarp on the load.
Turning in detail to the figures,
The frame assembly 12 may be a pallet or skid that is modified to include the features described herein. The frame assembly 12 includes attachment apparatus in order to permit the frame assembly 12 to be attached to a lifting device, such as a forklift (not shown in
The frame assembly 12 also includes legs 20 that are useful for positioning the mounting structure, such as the top plate 16 at a desired height above the ground. Preferably, the legs 20 will be of sufficient height such that the roller assembly 14 has sufficient ground clearance when a full tarp is completely wound around the roller assembly 14. Additionally, elevating the roller assembly 14 makes the tarp deploying apparatus 10 more ergonomic by positioning the roller assembly 14 at a convenient height for rolling the tarp onto the roller. The legs 20 may be supported by angular braces 22 in order to improve structural integrity and provide desired stiffness for the frame assembly 12 as a whole. Furthermore, the legs 20 may be provided with feet 24 to better distribute the weight of the tarp deploying apparatus 10 and provide better stability.
A counterbalance weight 26 may be provided on the frame assembly 12 at an opposite side of the frame assembly 12 from the roller assembly 14. The counterbalance weight 26 helps to maintain the center of mass of the entire tarp deploying apparatus 10 at or between the attachment sleeves 18, even when a full tarp is provided on the roller assembly 14. This can be important to prevent a significant twisting or tipping moment from being applied to the tarp deploying apparatus 10, and thereby to the forklift, when in use with a tarp on the tarp roller 14. The counterbalance weight 26 may be any suitable structure that sufficiently counterbalances the weight of the roller assembly 14 and tarp.
For example, the counterbalance weight 26 might be lengths of I-beam, concrete ballast, cinder blocks, or other similar items.
The roller assembly 14 includes a spindle 28 fixed to the top plate 16. In the embodiment shown, the spindle 28 is welded to the top plate 16. Additionally, the spindle 28 is secured to the top plate 16 by u-shaped brackets 30. The u-shaped brackets 30 are threaded on each leg, and extend through the top plate 16. The u-shaped brackets 30 are held in place by nuts and washers (not shown). The nuts and washers may be welded in place to provide a secure connection. Those of skill in the art will be aware of numerous mechanisms for fixing the spindle 28 to the top plate 16 in a satisfactory manner. According to one embodiment, the spindle 28 is a solid shaft having an outer diameter of about two inches. According to the embodiment shown, the spindle 28 is about twelve feet in length. The spindle 28 is cantilever mounted to the frame assembly 12, such that about eight feet of the spindle 28 extends laterally beyond the edge of the top plate 16 to which it is mounted. Those of skill in the art will be able to determine other suitable dimensions and materials for the spindle 28. For example, the spindle 28 might appropriately be formed from a hollow pipe, rather than a solid shaft, if appropriate materials and dimensions are selected.
A roller body 32 is journaled around the free end of the spindle 28. The roller body 32 extends laterally a distance farther than the spindle 28. In the embodiment shown, the roller body 32 extends about an additional four feet beyond the end of the spindle 28. The roller body 32 is mounted for free rotation about the spindle 28. The roller body 32 may be a hollow cylinder formed from a hard durable material, such as a suitable metal. As seen in
The roller body 32 is provided with an end cap 36 that prevents dirt, water, and other impediments from getting into the roller body 32 and impeding the free rolling of the roller body 32 around the spindle 28. A handle in the form of wheel 38 is provided on the roller body 32 near to the frame 12. The wheel 38 allows a user to rotate the roller body 32 around the spindle 28 by grasping the wheel and turning it in either direction. The wheel 38 serves to provide an easy and convenient element for a user to grab, and provides a mechanical advantage to make rotation of the roller body 32 easy to accomplish. In the embodiment shown, the wheel 38 has an outer diameter of about 2 feet. As best seen in
The tarp deploying apparatus 10 may also be provided with a braking or slowing apparatus so that as the tarp is being deployed, the momentum of the spinning roller body 32 with the tarp rolled upon it does not continue to spin, or unroll too fast during deployment. In particular, a resilient brake flap 60 is provided that extends from the top plate 16 towards the wheel 38. The brake flap 60 is secured to the top plate 16 by a securement plate 62. The brake flap 60 extends far enough beyond the edge of the top plate 16, such that it interferes with the spokes 42 of the wheel 38, as the wheel rotates. The brake flap 60 should have enough stiffness to provide resistance to rotation of the wheel 38, but should be flexible enough to permit the spokes 42 to move the flap 60 out of the way such that the wheel 38 can continue to rotate. In the embodiment shown, the brake flap 60 is formed from a sheet of plastic. The securement plate 62 is a thin metal plate that is secured to the top plate 16 via threated fasteners. Preferably, the threaded fasteners will also pass through and lock the brake flap 60 in place. The brake flap 60 may wear, or lose resilience over time and through use of the apparatus 10. If that occurs, the brake flap 60 may be replaced by unscrewing the threaded fasteners, removing the securement plate 62, removing the old brake flap 60, and inserting a new brake flap 60.
A series of hooks 44 are provided on the roller body 32. The hooks 44 should be in alignment with each other along the length of the roller body 32. The hooks 44 should be spaced apart to match the spacing of eyelets 52 provided on a standard tarp 50. Typically, the hooks 44 will be provided about 18 inches to 2 feet from each other. As best seen in
The hook 44 shown in broken lines is rotated into a position where it will freely release the tarp 50 to automatically drop off of the roller body 32.
The hooks 44 may be attached to the roller body 32 in a variety of fashions. In the embodiment shown, each of the hooks 44 include a threaded portion (not shown), that is received within a threaded hole 64. Several threaded holes 64 are provided along the length of the roller body 32, such that the locations of the hooks 44 can be adjusted to match tarps having eyelets in varying locations. Other mechanisms that permit adjustment of the location of the hooks may also be used, such as elongated slots, hook and loop fasteners (e.g., Velcro), or other known mechanisms. Alternatively, the hooks 44 may be welded in place spaced apart at a common distance for eyelets.
As the forklift continues to move along the side of the flatbed trailer 58, the tarp 50 continues to unroll off of the roller body 32 to be deployed upon the top of the cargo 56. The person driving the forklift will continue to move the forklift 54 until the roller body 32 is beyond the cargo 56. Eventually, the tarp 50 will be completely unrolled off of the roller body 32. As described above with respect to
As the forklift moves along the flatbed trailer 58 during deployment of the tarp 50, the forklift 54 may slow down as it raises and lowers the roller body 32 to match the contours of the cargo 56. The momentum of the roller body 32 with the rolled up tarp 50 will cause it to continue to rotate, and deploy the tarp 50. This can lead to bunching or puckering of the tarp 50. However, the brake flap 60 provides resistance to the rotation of the wheel 38, and thereby slows the rotation of the roller body 32 in order to reduce this phenomenon.
The foregoing drawings and description are of preferred examples for implementing the invention only. The scope of the invention should not be limited by this description. The scope of the invention is defined by the following claims. Those of skill in the art will be aware of additional features and modifications that can be made to these shown and described embodiments that will implement the invention and will fall within the scope of the claims.
