Patent Application
20060138273
The invention relates generally to the field of roll handling, and in particular to a system for accurately positioning a roll handling cart, and transferring stock rolls of web to and from a cart.
In many kinds of roll handling carts, such as those described in U.S. Pat. Nos. 5,674,040 and 5,934,604, stock rolls are supported on their outside convolution of web, which can damage several of the outer web convolutions of the stock roll. To eliminate the damage to the web, stock rolls are often horizontally supported by a cantilevered support spindle, which supports a stack of stock rolls by the inner diameter of their cores. U.S. Pat. No. 5,165,767 and European Patent No. EP 1 211 554 A1 illustrate such carts. However, in some cases, because the inner diameter of the core is not sufficiently large enough, and the weight of the stack of stock rolls is too great, a horizontal cantilevered support is not practical.
In U.S. Patent Application Publication U.S. 2002/0054811, an apparatus uses an expansion assembly incorporated within a support mandrel to hold the inner bore of the stock roll's core. This method can be problematic when transferring some configurations of stock rolls in the vertical orientation, because the stock rolls may have been loosely wound, or the weight of the wound web will pull off its core. Also, when loading or unloading a machine process spindle with a stock roll of web, the stock roll core bore needs to be open and accessible. Sometimes the expansion force against the core bore is too great and damages the core. Therefore, the apparatus described in U.S. Patent Application Publication U.S. 2002/0054811 has limitations, and is not practical for use with large rolls of motion picture film, for example.
To automatically remove stock rolls from a cart and transfer the stock rolls to an adjacent machine process can require a means to accurately locate the stack of stock rolls which reside on the cart, and a means to accurately position the cart. In many kinds of carts, such as those disclosed in European Patent No. EP 1 211 554 A1, the final located position of the cart requires the wheels, which remain in contact with the floor or a platform surface, to accurately position the elevation of the cart. This can be problematic, because the cart's wheels are subject to wear and can collect dirt. Therefore, there is a need to accurately locate a cart without the critical setup or alignment of its wheels.
There is a need for automatic roll handling systems which can “accurately” load or unload stock rolls of web, such as motion picture film, to or from a machine which processes, or performs other operations upon this web. There is also a need to automatically handle a significant number of stock rolls to greatly reduce the operational labor requirements such as manually lifting and transferring stock rolls. There is also a need for an automatic roll handling system, which handles the stock rolls in a safe manner to minimize the creation of handling defects. There is also a need for an automatic roll handling system which can work effectively in a dark room environment, which is required for handling light sensitive materials. Finally, there is need for a simple and low cost system, which can meet these requirements
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, an automated roll handling system is provided, comprising a cart with an integrated vertical spindle comprising, and a plurality of wheels on bottom frame of the cart. A trio of cart locating pads situated on the bottom frame of the cart, and a cart centering post situated on the bottom frame of the cart and used in combination with the trio of cart locating pads to locate the spindle in space to a predetermined positioning tolerance that allows for control of five degrees of freedom is provided. A roll transfer system, is also provided comprising a pivot arm, a system frame for supporting the pivot arm, a vacuum arm that is capable of sliding within the pivot arm, a plurality of vacuum suction cups affixed to the vacuum arm for holding a sidewall of a stock roll, and a cart locator system on the bottom of the system frame for precise positioning of the cart using the combination of the trio of cart locating pads and the cart centering post.
The present invention provides a means of transferring a stock roll of web without contacting or supporting the outer convolutions of web, and thus eliminates the risk of damaging the outer convolutions of web. The present invention also provides a means of stacking stock rolls on their sidewalls, in a cart, and precisely locating the stack of stock rolls via their cores' inner diameters to protect and accurately position the stock rolls.
The present invention provides a means to accurately locate the cart without the use of its wheels. A simple and accurate system for loading and unloading stock rolls to and from a cart and onto and off of a machine is also provided.
These and other aspects, features, and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
Based on the prevailing needs and inadequate solutions mentioned above, it is desirable in this case to support the stack of rolls on their sides to prevent damage to the stock rolls outer convolutions, and also provide a means to accurately locate the stack of stock rolls via their cores inside diameters, by use of a vertical spindle integrated into the cart. Also, it is desirable to accurately locate a cart and the stack of stock rolls it carries independent of the cart's wheels.
Referring to
Cart
The cart 2, illustrated in
Stock Roll Transfer System
The stock roll transfer system 1, illustrated in
Inside the tube structure of pivot arm 20, seen in
Vacuum suction cups 26 are designed to support a single stock roll of web by holding the web's sidewall with sufficient vacuum pressure. The vacuum arm's 21 tube inner opening is designed to clear the diameter of the cart spindle 7 when acquiring a stock roll 9.
The lower section of the stock roll transfer system 1, as shown in
Controls
The stock roll transfer system 1 uses a vacuum supply, (not shown), for the evacuation of air to the vacuum suction cups 26, which could be supplied from a factory vacuum, a vacuum pump, a compressed air vacuum generator, or other means. The rodless cylinder 23 can be any pneumatic or hydraulic device, which is commercially available, or it could be configured as linear electrical drive. The control for these devices can be performed by an independent controller or by the one used by the adjacent machine 3.
Basic Control Functions:
Head vacuum on/off
Pivot arm rotation CW/CCW
Vacuum arm extension in/out
Stop cylinder in/out
Cart latch closed/open
Cart lifting devices up/down
The exemplary steps of operation for loading stock rolls 9 onto the machine 3 are as follows:
(1) The cart 2 is manually pushed into the stock roll transfer system 1 docking location, as initially illustrated in
(2) The locator latch cylinder 17 is energized and subsequently actuates the cart locator latch 16 against the cart center post 12 accurately and securely against the locator 15. This actuation accurately locates the X and Y positions of the cart 2, as depicted in
(3) The three cart lifting devices 14 A-C are actuated to engage with the three cart locating pads 8 A-8C, and lift the cart 2 slightly off the floor, so the cart wheels 6 no longer have positional control of the cart 2. Now the cart 2 has been accurately positioned in preparation for the stock roll unload steps, seen in
(4) The vacuum arm 21, which is initially in its vertical position and fully retracted, also shown in
(5) The vacuum arm 21 is now fully retracted by the actuation of the rodless cylinder 23, as seen in
(6) The rotary actuator 19 is actuated to rotate the pivot arm 20 in the horizontal position, where it comes to rest against pivot arm horizontal stop 24, as seen in
(7) The stop cylinder 28 is actuated to limit the travel of the rodless cylinder 23 forward stroke.
(8) The vacuum arm 21 is extended outward via the actuation of the rodless cylinder 23, until it is stopped by the stop cylinder 28. This motion delivers the stock roll 9 accurately over the machine spindle 4, which is a collapse state, as seen in
(9) The machine spindle 4 is activated to grasp the inner diameter of core 10.
(10) The vacuum cups 26 vacuum is de-energized to release hold of the stock roll 9.
(11) The vacuum arm 21 is fully retracted via the actuation of the rodless cylinder 23.
(12) The pivot arm 20 is rotated via the rotary actuator 19, until the pivot arm 20 comes to rest against pivot arm vertical stop 25, seen in
(13) The vacuum suction cups 26 vacuum pressure is energized when the next automatic command is given to acquire and load another stock roll 9 onto the machine spindle 4.
Although the steps to unload a stock roll 9 from a machine are not described, it is obvious to those ordinarily skilled in the art that reversing the process steps provides this capability.
The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
