Patent Application
20060245889
1. Field of the Invention
The present invention relates generally to material handling. More particularly, the present invention relates to a device and method for lifting, positioning and transporting rolls of material wrapped about a hollow cylindrical core.
2. Related Art
Many manufacturing processes require the use of various materials such as packaging, film, plastic, paper, or foil which are normally supplied to machinery in roll form. Modern machinery, which has become larger and faster, requires larger rolls containing more material in order to reduce the need for shut down or production delays during roll changes. These larger rolls, up to 24 inches or more in width, and 40 inches in diameter, can weigh over 800 pounds. At the same time, a large percentage of rolls still range from 50 to 200 pounds. Safety requirements for repetitive lifts, such as those imposed by the Occupational Safety and Health Administration (OSHA), recommend the use of mechanical assist devices for such rolls, even where they could be manually lifted. Smaller rolls are commonly placed side-by-side on a palette, requiring a lifting device to be capable of positioning over nearly the entire surface of the palette.
The preferred method of roll shipment is on a pallet, or other similar support or container, with the roll core in the vertical position (core vertical). Shipment of the roll in an upright position (core horizontal) requires blocking or chocking the rolls to prevent instability, and often results in damage to the material or machinery upon use, due to imbalance created during transport or storage.
Nearly all machinery requires the roll to be in the core horizontal position during use. Because most rolls too heavy for repetitive human manipulation, a mechanical method of manipulating rolls from the preferred shipping position (core vertical), to the use position (core horizontal), and transporting them from the storage or shipping site to the machinery is needed. This mechanical method, in the past, has generally been by the use of general purpose machines such as fork lifts or palette jacks.
After the rolled material has been removed from storage or shipping and transported to the site of use it remains in the core-vertical orientation. Positioning the roll on a mandrel for utilization of machinery has often been accomplished in a make-shift way. While fork lifts and other individual roll-delivery devices have the means to manipulate an object vertically, they often do not have the capability of moving an object in other directions. Use of vertical lift-only equipment may result in attempts to manually manipulate the rolls from the core vertical position to the core horizontal position, often resulting in damage to the roll stock and even injury to technicians.
Another drawback with the use of general purpose machines, such as fork lifts is that they are relatively expensive. More flexible, safer, and cleaner general purpose designs are increasingly expensive, and this kind of expense is not warranted when a commercial application only requires the efficient manipulation and transport of heavy rolled materials.
To address some of the disadvantages mentioned above, smaller special use machines have been developed solely for lifting and manipulating rolled materials. Unfortunately, while many of these special use machines do accomplish their intended purpose, they tend to be bulky, awkward, and expensive. These machines also allow the palette to be approached, but cannot effectively maneuver over the surface of the palette. Some of these machines are difficult to manipulate, and tend to block the view of the operator. Additionally, it can be difficult for a potential purchaser of such a machine to justify a large expense for a machine that has only one use.
It has been recognized that it would be advantageous to develop a rolled material manipulation machine that is relatively small, lightweight, and easy to maneuver, and which can be maneuvered over a support palette.
It has also been recognized that it would be advantageous to develop a rolled material manipulation machine that provides better visibility for an operator.
It has also been recognized that it would be advantageous to develop a rolled material manipulation machine that is mechanically simple.
In accordance with one aspect thereof, the invention provides a device for lifting and manipulating a roll of material, including a wheeled frame, including a pair of forwardly extending, spaced-apart legs, configured to straddle a palette. A cross bar is disposed atop and extends between the legs, and has an elevation sufficient to pass over the palette. A single column is laterally moveably disposed atop the cross bar, and a roll lifting and manipulating mechanism is attached to the column. The roll lifting and manipulating mechanism is configured to engage a vertically oriented hollow cylindrical core of the roll of material, lift the roll, and rotate the roll to a position with the core substantially horizontal.
In accordance with another aspect thereof, the invention provides a method for lifting and manipulating a roll of material. The method includes the steps of: positioning a moveable frame, having an elevated transverse support configured to pass above a palette, in straddling relationship with a palette, and manipulating the frame so as to forwardly align a roll-engaging device, attached to the frame, with a substantially vertical hollow core of a roll of material supported on the palette; laterally sliding a single vertical column, moveably disposed upon the transverse support, so as to laterally align the roll-engaging device with the core; engaging the roll-engaging device with the core; lifting the roll-engaging device upon the vertical column so as to lift the roll above the palette; and rotating the roll-engaging device to position the core substantially horizontally.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention, and wherein:
Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.
As noted above, roll materials are frequently shipped and stored on a palette with the roll core in the vertical position. However, use of the roll usually requires lifting and rotating the roll to a position with the core horizontal. Consequently, a variety of machines and methods have been developed for lifting and manipulating rolled materials. Some of these comprise modifications to general purpose equipment, such as a fork lift. Other specialty devices have also been developed specifically for lifting and manipulating rolled materials.
One prior roll manipulating device is shown in
Movably attached to the vertical support members 22 is a horizontal support assembly, including a rear lift plate 30 and front lift plate 32, with associated struts and bearings. The bearings move in the inwardly facing channels of the vertical support members, so as to provide a vertical path of travel for the horizontal support. Also included in the horizontal support are horizontal channels 38 which provide a substantially horizontal path of travel for the front lift plate. A lift post 44 extends from the front lift plate, and an expandable mandrel 52 is pivotally attached to the lift post via a pivot assembly 50. Lateral adjustment of the position of the lift post 44 can be accomplished by means of a horizontal hydraulic cylinder 74 associated with the horizontal lift assembly. This cylinder is attached between lift plates 30 and 32, and causes the plates and their respective structure to move in relation to each other.
The mandrel 52 is configured to insert into the vertically oriented core 12 of the roll 10, and expand to grip the roll, to allow the roll to be lifted by the horizontal lift assembly, which is accomplished by a hydraulic lift cylinder 72 attached at its base to the main support member 16 and at its top to the horizontal lift assembly. The mandrel has an approximately 90° range of travel, from a substantially vertical position (shown in
The various hydraulic cylinders required to operate the device of
Advantageously, the inventor has developed a new device 110 for lifting and manipulating rolls of material, various views of one embodiment of which are shown in
Disposed atop the cross bar 120 is a single upright column 122. The column is laterally moveable, being supported upon a lateral shifting mechanism 124 disposed atop the cross bar. A detail perspective view of the lateral shifting mechanism is shown in
The lateral shifting mechanism 124 also includes structure for limiting an extent of lateral travel of the column 122 upon the sliding bearing 126. In the embodiment shown in the figures, the lower back side 134 of the cross bar 120 includes an elongate slot 136 that is aligned with the elongate bearing 126, and has a length that is slightly less than the length of the elongate bearing (W2 in
Referring again to
Slidably connected to the column 122 is a roll lifting and manipulating mechanism 144 that is configured to engage the vertically oriented hollow cylindrical core 146 of the roll of material 148, lift the roll, and rotate the roll to a position with the core substantially horizontal. Various views of this mechanism are provided in
The mandrel 152 is pivotal between a substantially downwardly oriented position (shown in, e.g.,
Viewing
The mandrel 152 is configured to insert downwardly into and engage the hollow cylindrical core 146 of a roll of material 148. A variety of types of mandrels configured to mechanically engage the core of a roll can be used. In the embodiment shown in the figures, the mandrel is an expanding mandrel, having a resilient rubber bushing 184 that is configured to expand to contact the inside of the hollow tubular core of the roll, as depicted in
The combination of the elevated cross bar 120 and the lateral shifting mechanism 124 for the single column 122 provide a variety of advantages in the present invention. Because the cross bar is elevated, it can pass over or above the top of a palette 118 (or other support) to reach rolls of material 148, as depicted in
Advantageously, because the cross bar 120 of the present device can pass over the palette 118, the length LA of the lifting arm 150 need not be so long, and the arm can therefore be a smaller, lighter structure. Additionally, because the lifting arm is shorter, the support legs 114 can also be shorter because the center of mass of the device when loaded will be closer to the rear. Specifically, the length LL of the support legs can be substantially less than the lateral spacing W1 between the legs. In one operative example, where the length LA of the lifting arm is 12 inches, and the lateral spacing W1 between the legs is 52 inches, the legs can have a length LL of 24 inches.
Additionally, the lateral shifting capability of the upright column 122 allows the distal end of the lifting arm 150 and the mandrel 152 to be positioned over rolls 148 positioned near the sides of a support palette 118. Use of the device is thus very simple, and is illustrated in
Once aligned with the vertical core 146, the user lowers the lifting arm 150 so as to insert the mandrel 152 down into the core, in the direction of arrow 192, and then mechanically engages the mandrel with the core, as shown in
Once the core 146 is horizontal, the user can move the roll manipulating device 110—with the roll attached—to a location adjacent to a point of use for the rolled material, such as to a machine (not shown) having a horizontal spool, shaft, or axle configured to receive the roll. It is usually desirable to transport the roll upon the machine with the core in the horizontal position, so that the roll is not as likely to fall off if the mandrel were to loosen. Additionally, for maximum stability and safety, the lifting arm 150 can be kept at a relatively low elevation while moving the device with a roll attached, so that the center of gravity of the device is maintained relatively low. If needed, the user can lower the arm 150 after rotating the roll to the horizontal position.
Upon arrival at a point of use for the roll 148, the user aligns the core 146 of the roll with the spool or axle (not shown) of the receiving machine by any needed combination of rolling the frame 112 upon the floor, adjusting the lateral shifting mechanism 124, and adjusting the height of the roll with the winch mechanism 156. Because the mandrel 152 does not ordinarily extend entirely through the core of the roll, a portion of the inside of the core at its far end (referring to the horizontal orientation) is typically unobstructed, allowing a portion of the end of the core to be slid onto a receiving spool or shaft while the roll remains on the mandrel. When the core is properly aligned with the spool or axle of the receiving machine, the user then releases the grip of the mandrel by rotating the mandrel tightening mechanism (e.g. the adjustment nut 186) in a direction opposite to the tightening direction. Once the grip of the mandrel is released, the roll can be easily slid horizontally from the mandrel and onto the receiving shaft, and secured in place. To return the mandrel to the vertical position, the user simply opens the release valve 182 of the hydraulic system, allowing the mandrel to rotate downward under its own weight, and the roll manipulating device is then ready for use elsewhere.
The invention thus provides a smaller, lighter-weight, and less expensive device for lifting and manipulating heavy rolls of material. Its single column design provides better visibility for the operator, and the small size of the machine makes it easier to maneuver. Its elevated transverse member allows the device to have shorter legs and a shorter lifting arm, yet still reach rolls on far edges of support palettes. Additionally, its use of manually operable devices, such as the manual winch and manually powered hydraulic system, eliminate the need for heavy and expensive motors or other power sources.
While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
