Not Applicable
Not Applicable
1. Field
This application relates to check weighing conveyors, specifically those which are incorporated into an inclined take away conveyor to convey product from a bag making machine, such as a vertical form fill and seal machine.
2. Prior Art
When a package is made from a bag machine, the finished bag must be conveyed out from the underside of the machine to the check weigher. Ideally, the section of conveyor that the package first touches should be at nearly floor level. This low profile allows for clearance between the seal jaws of the bag machine to keep from deforming the bag as it exits the machine. Additionally, this first conveyor section should preferably be angled to assist in controlling the fall of the finished bag. If the finished bags hit a horizontal conveyor when they drop from a bag machine, some bagged items tend to shift within the bag causing a portion of it to be inaccurately weighed.
Once the bag is clear of the machine, it must be conveyed to a scale section to weigh the bag. Following the weighing of the bag, it must be conveyed to a comfortable height for workers to package the bag into boxes or on a pallet. Since floor space is a concern in most packaging companies, it is the intent of this invention to minimize the horizontal space needed for placement of a check weighing scale without sacrificing package quality or product flow.
U.S. Pat. No. 4,788,930 to Matteau (1988) shows an inclined conveyor which reduces the horizontal space needed for installation, but lacks the adjustable infeed section and the accuracy of a substantially horizontal scale section.
U.S. Pat. No. 3,096,837 to Abbott (1963) shows a horizontal scale section combined with a fixed angle inclined conveyor that is positioned below a horizontal conveyor. This position may cause damage to finished bags due to the vertical drop as well as increasing the functional height of the conveyor system. U.S. Pat. No. 7,048,109 to Brixius (2006) is another example of a fixed incline conveyor albeit for the vastly different application of baggage handling.
The check weighers described in U.S. Pat. No. 3,379,234 to Kasper (1968), U.S. Pat. No. 3,484,813 to Davies (1969), and U.S. Pat. No. 4,065,911 to Fagan (1978) describe improvements primarily to the scale control, but do not address the problem of clearance below a bag making machine.
U.S. Pat. No. 5,304,745 to Rusk (1994) teaches a modular checkweighing and conveying system. Although this invention could be made shorter to allow for clearance between the floor and the bag machine, it lacks the adjustability required to adapt to varying bag lengths and machine types.
In accordance with one embodiment a weight checking conveyor with adjustable infeed section comprises three conveyor sections, an infeed section, a check weighing section, and an outfeed or take-away section. The infeed conveyor section is pivotably mounted to a horizontal weight checking conveyor. The angle of the infeed section may be increased to allow positioning under a vertical form fill and seal bag making machine, or decreased to prevent product damage as it falls from the bag making machine. The check weighing conveyor section is preferably horizontal to increase weighing accuracy. The outfeed conveyor section is preferably inclined to deliver finished product to a manageable working height for personnel packing product into shipping cartons.
One embodiment of the weight checking conveyor with adjustable infeed section is shown in
The check weighing section 2 of the conveyor contains front and rear photoelectric sensors 11 that sense the presence of product on the conveyor and send an electrical signal to output the weight of the product to a computer 12. If desired, the photoelectric sensors 11 can also provide a signal to momentarily stop the check weighing section belt 13 as well.
Once the finished product passes the check weighing section 2 of the conveyor, it is moved upward by an inclined outfeed conveyor 14 to either a secure reject bin 15 or a downstream boxing or palletizing area. The destination of the final package is determined by the check weighing load cell 16 and provides a signal to a pivotal plate 17 that diverts the flow of the package. The secure or lockable reject bin 15 is necessary to prevent tampering of operators that may ship underweight or overweight product to consumers. It is also an advantage to move the product from nearly ground level to the optimum working height of final packaging personnel.
The check weighing section frame 6 and the inclined outfeed conveyor frame 18 is fastened to a main support frame 19. The frames of all sections are preferably made of stainless steel for washdown purposes in a food packing facility.
Since different products require different belts for transporting them, the check weighing section 2 is preferably pivotably mounted to the main conveyor frame 19 with an adjusting bolt 20 at the front and rear of the machine to allow clearance between the outfeed conveyor belt 21 and the check weigh section belt 13. The check weigh section 2 is adjusted by loosening the adjusting bolts 20 and pivoting the check weigh conveyor section 2 slightly about the mounting bolts 22. The length of the slot 23 determines the maximum and minimum degree of rotation relative to the outfeed conveyor 14. The short slot 23 allows for minor clearance adjustments between the check weighing 2 and outfeed conveyor belt 21 but holds the check weighing section 2 substantially horizontal to maintain weighing accuracy.
After adjusting the angle of the check weighing section 2, the assembly is held firmly in place by tightening the adjusting bolts 20 at the operator side and rear of the machine.
The outfeed conveyor 14 is driven by a primary conveyor drive pulley 24 and may consist of a second outfeed conveyor 25 and driven by a secondary conveyor drive pulley 26 also fastened to the main support frame 19.
This application claims the benefit of provisional patent application Ser. No. 61/197,354, Filed 2008 Oct. 27 by the present inventor.
Number | Date | Country | |
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61197354 | Oct 2008 | US |