Rolled or coiled material can range from paper to metal. The rolled material is generally quite thin in relation to the unrolled length and the rolls can typically weigh hundreds to thousands of pounds. These weights, combined with the fragile nature of the thin sheet material, can lead to significant damage to the outer layers and the edges of the roll, especially when the rolls are being repositioned during shipping or receiving.
When processing sheet material, whether manufacturing the sheet itself or during secondary processing such as continuous roll forming, the roll is typically mounted through its center hole on a horizontal spindle or mandrel so that the material may be either rolled or unrolled depending on the application. However, when shipping, storing, and moving the rolls around a warehouse, the roll is most often positioned on its flat side with its center hole vertical. Some advantages of each configuration are fairly obvious: horizontal positioning permits rolling or unrolling the linear stock while the roll turns on a stationary horizontal axis with the weight of the roll supported on the inner spindle and the edges untouched (and undamaged)—vertical positioning places the roll in a stable position so that it can be placed on a pallet and moved using various conventional material handling equipment like forklifts and pallet jacks. The problem arises as to how to transition the roll between vertical and horizontal positions in a manner that protects both the roll and the workers moving the roll.
The job of mounting a palleted roll onto a spindle, for example, a feeder spindle for a roll forming process, is often left to warehouse workers or machine operators who must muscle the roll into position with fork lifts and makeshift slings. Moving these heavy rolls with manpower and improvised tools involves a good deal of manual handling during which the outer layers and edges of the roll can be damaged, deformed, and scratched. In addition, manhandling a 5000 lb roll of sheet steel to thread a sling through the center hole and between the pallet and the roll itself can result in various injuries, from cuts and scratches to broken limbs. Damaged material (i.e., scratched, dented, bent, etc.) must be cut from the roll and discarded prior to further processing, resulting in unnecessary scrap losses.
Conventional roll tilters (sometimes called up-enders) ate helpful in changing the position of rolls from their usual shipping position (with vertical central axis) to a horizontal position suitable for mounting the roll on an unrolling fixture, or, on the other hand, removing a roll mounted on a spindle and transferring it to a pallet for shipping or storage. Roll tilters can be massive, highly automated machines. Such tilters may be found in factories and specialized shops that work with rolled material on a regular basis. Some basic, stripped-down roll tilters have been produced for handling smaller rolls on a more occasional basis. However, in addition to the basic tilters being less robust and prime to malfunction, the rolls manipulated by currently available basic roll tilters are still vulnerable to damage while on the roll tilter.
Once in the horizontal position, the rolls must be freed from their shipping pallets. The weight of the roll makes this process challenging. Often freeing the pallet causes edge and surface damage to the roll and/or destroys the pallet. Mounting the roll on an unrolling fixture may require additional movement to clear the centerhole (e.g., remove the pallet) to accept a spindle from which the material can be continuously unrolled for forming. There exists a need for a compact yet full-featured roll tilter that can operate reliably and safely with minimal setup.
The unique roll tilter assembly described in this disclosure and accompanying figures includes several novel features that solve many problems encountered when handling rolled material.
In this specification, like reference numbers appearing in multiple drawing figures indicate the same or similar elements.
The Compact Roll Tilter finds utility at least for positioning rolls of sheet and thin plate material. Such rolls are typically shipped and/or stored in a vertical position (i.e., with the centerline of the roll extending along a vertical axis) resting on a pallet. After shipping and prior to use, a roll is often mounted on an unspooling fixture having a horizontal spindle extending through the center hole of the roll. Once mounted on the unspooling fixture, the material of the roll can be unwound for further processing such as forming, cutting, bending, and trimming. Of course, the Compact Roll Tilter can be employed with equal success when demounting a roll from a horizontal position and transitioning the roll 90° to a vertical position for placement on a pallet.
Oftentimes, changing the roll position from vertical (as shipped) to horizontal (for unspooling) is done by forklift or a hoist connected to a lifting strap threaded through the roll center hole. Due to the weight and general ungainliness of the rolls, it can be difficult to separate the roll and pallet, i.e., the lifting strap may capture the pallet along with the roll. Alternatively, the roll may be tilted by hand, lifting up one edge of the roll, to allow the strap to be pulled through the center hole to the perimeter of the roll, excluding the pallet itself. This process may be difficult and dangerous with a risk of pinching extremities between the roll and the pallet or trapping a worker's hand or arm under the roll.
The Compact Roll Tilter provides mechanized means for moving the roll and pallet between the vertical and the horizontal positions while minimizing hazards related to moving such large and heavy objects. In addition, the Compact Roll Tilter has unique features that facilitate the moving and mounting processes.
The pivot assembly 20 includes two platform components positioned at substantially right angles to each other and joined along a common side. “Substantially,” as used here and throughout, is meant to accommodate conventional dimensional tolerances and the inconsistencies that are inherent in standard manufacturing processes. The slotted platform 22 supports the roll in the vertical position (see
Also shown in
In the vertical position, the linear actuator (not shown in 2A) is fully extended, causing the rollers 28 to move forward along the roller platform 52. When the linear actuator is retracted, the rigid side links (also not shown in 2A), in concert with the retraction of the linear actuator 51, cause the pivot assembly 20 to rotate about the pivot axis 25 (also the link connection point) to the horizontal position shown in
In
In
As pivot assembly 20 rotates and the cradle platform 21 approaches horizontal, the lower ends of the cradle latches 214 contact the base bracket 50, and further rotation of the pivot assembly 20 causes the cradle latches 214 disengage from the latch pins 33. Also, as the cradle platform 21 approaches horizontal, the cradle wedges 54 engage the edge of the near side cradle section 32. Further rotation of the pivot assembly 20 results in the fixed cradle wedges 54 shifting the cradle assembly 30 a short distance along the cradle platform 21, releasing the pallet 42 from being clamped between the slotted platform 22 and the roll 40. Releasing the pallet 42 is important because the pallet 42 should be removed before inserting an unrolling spindle through the roll center hole. Once the pallet 42 is removed, the spindle slot 23 in the slotted platform 22 provides an open path to insert the spindle and lift the roll 40 with the spindle inserted.
Pivot Action
The pivot assembly utilizes a novel linkage and actuator combination that shortens the overall length of the base bracket 50 while providing a smooth transition between the vertical and horizontal positions.
The linear actuator provides the force to rotate the pivot assembly in either direction The linear actuator is anchored to the base bracket 50 and connects to the pivot assembly proximal the roller axis 29. Both linear actuator connections are effectively pinned connections that allow for rotation at the connection points. The rigid side links 53 are also pinned to the base bracket 50 and to the pivot assembly 20; however, the link connections to the pivot assembly are offset upwards from the linear actuator connection point. The offset distance between the link and linear actuator connections provides a moment arm that facilitates the rotation by the linear actuator and, because the link connection is always vertically offset from the linear actuator connection, the moment arm is present to some degree throughout the entire rotation of the pivot assembly, i.e., from the vertical to the horizontal position.
In addition to maintaining the moment arm, the side link/actuator link configuration enables the rollers 28 to reciprocate from one end of the roller platform to the other during rotation which, in turn, enables the pivot assembly to overlap a span of the base bracket approximately equal to the width of the roller platform—shortening the envelope of the pivot assembly as it moves between the vertical and horizontal positions.
Cradle Assembly
Rolls of sheet material require careful handling, since the small thickness of the sheet can make the material vulnerable to kinks, wrinkles, dents, and other surface damage. Additionally, some sheet materials are pre-painted or otherwise pre-finished before rolling, making the surface even more susceptible to surface damage. The roll tilter 10 incorporates a unique cradle assembly 30 that provides particular protection for the roll material
The cradle assembly 30 rests on the cradle platform 21. The cradles are captured and retained on the cradle platform 21 in part by the cradle fences 27 on either side of the cradle platform 21. The cradle fences 27 permit sliding movement along the cradle platform 21 to facilitate easy assembly and also to enable the movement imposed by the cradle wedges 54 as the pivot assembly 20 moves into the horizontal position with a roll in place on the cradles.
The building blocks of the cradle assembly 30 are the individual cradle sections 32, illustrated in
Additionally, the height of the cradle cushions 34, 36 from the cradle platform 21 can provide necessary clearance when mounting the roll on a spool. This height may be especially useful when the roll is to be mounted on a spool having flanges with diameters greater than the diameter of the roll. Such spools may be disassembled by removing at least one flange and insetting the spool barrel through the center hole of the roll. Then, the flange is reattached to the spool barrel opposite the remaining flange and the spool flanges effectively capture the roll on the spool.
The cushion may comprise resilient material such as nylon. Teflon and other synthetic materials, and may comprise wood or another relatively rigid material. In some applications, a cushion may be metal that is ground and/or polished to a highly smooth surface. The cushion may comprise combinations of material, or may be covered by a non-scratch or soft material. Various other materials and combinations thereof may be used for the cushion.
For wider or heavier rolls, the cradle assembly 30 can comprise one, two, or more individual cradle sections stacked along the cradle platform 21. The multiple configurations of cradle assemblies are useful for tailoring the roll tilter 10 for operation with different sized rolls. Depending on various factors such as roll material, material thickness, overall weight, and surface preparation, cradle sections 32 may be added to the assembly as needed to evenly support rolls of different widths and varying weights. In multiple cradle section assemblies, the support surfaces of adjacent cradle sections are attached to a single cushion that spans the multiple cradle sections and distributes the load across the cradle assembly. By spreading the roll load across multiple cradle sections, the cradle assembly 30 minimizes dents and kinks to the outer surface of the roll that may arise when a heavy roll overhangs a narrow cradle sections. The cushions that span multiple cradle sections, for example, the double cushions 36 shown in
Pallet Release Feature
In the vertical position, the weight of the toll may impose significant force on the pallet, effectively clamping the pallet between the slotted platform and the roll. When the pivot assembly 10 transitions to the horizontal position, the pallet may still be clamped between the roll 40 and the slotted platform, even though the weight of the roll is supported by the cradle assembly 30. Since the pallet can prevent a spindle from extending through the center hole of the roll, the pallet must be removed to allow the spindle to extend through the roll and into the spindle slot 23.
The roll tilter employs a novel wedge feature fixed to the base bracket 50 that engages the cradle assembly 30 as the pivot assembly approaches the horizontal position, and shifts the cradle assembly 30 away from the slotted platform 22 to release the pallet 40.
The cradle wedges 54, shown in
The cradle wedges 54 are configured to engage the edge of the nearside cradle section 32 when the pivot assembly 20 approaches the horizontal position. The edge of the cradle section 32 includes a bevel that matches the bevel at the tips of the cradle wedges 54.
In
Number | Date | Country | |
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62077863 | Nov 2014 | US |