Abstract:
An in line feed method and apparatus for forming slugs of incoming items, which are standing on edge and aligned front-to-back is disclosed. The process uses a conveyor belt and a vacuum chamber aligned end to end for separating the flow of items and creating slugs. The items introduced to the system are on a conveyor belt. The belt is periodically stopped and the items blocked from being sucked into the vacuum chamber. While the product is blocked from entering the vacuum chamber a moving finger which travels through the chamber is introduced at the mouth of the vacuum chamber and the items are released from the conveyor belt such that they are sucked into the vacuum chamber but are limited by and stack up against the finger. In this manner slugs are formed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to packaging machinery and more particularly to forming and transporting slugs of product by use of a vacuum. 
     2. Description of the Related Art 
     Serially produced product, such as cookies or crackers, lined up standing on end, front-to-back on a conveyor belt, needs to be formed into slugs for packaging. There are several problems associated with forming such slugs. If the product is front-to-back then a means for separating the product into uniform groups known as slugs, needs to be found which does not damage the product. The slugs must then be transported to the wrapping apparatus and wrapped, while maintaining the product in its front-to-back position. 
     In some packaging systems a product serially transported on a first conveyor belt is collected into slugs and transferred as rows of slugs to a second conveyor belt traveling perpendicularly to the first conveyor belt. This requires a 90 degree transfer of the slug&#39;s direction. Depending on the packaging methods, the slugs may have to be transferred again to a third conveyor belt perpendicular to the second conveyor for serial alignment of the slugs as required by some packaging machinery. Multiple handlings and orientations of product complicates the packaging process and damages the product. 
     In order to form slugs for a continuous line of incoming product, the product has to be stopped and a barrier introduced between slugs formed. The barrier must be inserted without impacting and damaging the product. The slug of product then needs to be pushed or otherwise moved out of the way for a new slug to be formed. The slug must be maintained with all product upright while being transported to the wrapping machine. 
     SUMMARY OF THE INVENTION 
     The invention uses a vacuum to pull product forward from a line of front-to-back product being transported on a conveyor belt. The product is released from the line of continuous front-to-back product in predetermined slug lengths. The slugs are then transported by the vacuum in a vacuum chamber having dimensions slightly larger than the cross section of the product. A stopping finger is inserted before each slug in the vacuum chamber to partition the slugs and to prevent the slug from moving too fast in the vacuum. A pushing finger is inserted after each slug to push it along against positive pressure in the downstream portion of the vacuum chamber, and to push the slug after it exits the vacuum chamber. The pushing finger may be used to propel the slug to the wrapping device. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to form slugs by use of a vacuum. 
     It is an object of the invention to transport slugs by use of a vacuum. 
     It is an object of the invention to create slugs without damaging the product. 
     It is an object of the invention to move slugs without damaging the product. 
     It is an object of the invention to increase slug forming and product wrapping rates. 
     It is an object of the invention to provide a slug feeding apparatus having an easily adjustable slug length or count. 
     It is an object of the invention to form slugs of product having variable size, shape and weight. 
     It is an object of the invention to separate product into slugs with an in-line feed. 
    
    
     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the Inline Vacuum Slug Feeder. 
     FIG. 2 is a cross section view of the Inline Vacuum Slug Feeder vacuum chamber with product. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A continuous line of cookies, crackers or other objects  40  are stacked in front-to-back fashion on an incoming conveyor belt  22  of in line slug feeder  20 . The in line slug feeder  20  may have side conveyor belts  24  for securing and advancing the product  40  in an upright position. The conveyor  22  has rollers  23  on each end of its length. The conveyor belt  22  is driven by motor (not shown) in conjunction with roller  31 . Conveyor belt  22  also passes over rollers  26 . Side conveyor belt  24  is also driven by the motor in conjunction with pulleys  28 ,  27  and  25 . The continuous line of product  40  is stopped from advancing at the end of the conveyor belts  22 ,  24  by release fingers  45  which hold the product from each side preventing the continuous line of a product  40  from being sucked into vacuum chamber  60 . The release fingers  45  are spring loaded for contacting and holding the product  40 . The product  40  is pushed past the release fingers  45  by the conveyor  22 . After discharge from the conveyor  22  the product  40  rides on rails  50 , is sucked into vacuum chamber  60  and stopped from forward advance by stop finger  70  which is attached to finger belt  77  having pulleys  75  at each end. By intermittent advancement of conveyor belt  22  by a prescribed distance, a slug of product having prescribed count is measured for release into vacuum chamber  60 . The release of product into vacuum chamber  60  is timed such that stop finger  70  is in place at the end of the vacuum chamber  60  nearest the conveyor belt  22  when product item  46  is released. Thus, product item  46  is sucked into vacuum chamber  60  by air flow  51  and stopped from further rapid forward advance by stop finger  70 . The suction in vacuum chamber  60  is provided by a vacuum  100 , connected to vacuum chamber  60 , at aperture  115 , by vacuum tube  110 . The position of aperture  115  is downstream of the length of a slug  44  from the mouth of the vacuum chamber  60  so that the entire slug  44  is sucked inside the vacuum chamber  60 . When the entire slug  44  is in the vacuum chamber  60  the flow of product  40  is cut off by releasing fingers  45  engaging the product  40  and holding it when the belt  22  stops advancing. The next stopping finger  70  is introduced adjacent the mouth of the vacuum chamber  60  awaiting release of the next product item  46 . The stop finger  70  regulates the speed of advancement of the product  40  in the vacuum chamber  60 . When the first product item  46  is stopped by stop finger  70  it provides a stop for the next product item in the line. The next product item is accelerated by air flow  51  and decelerated by a cushion of compressed air between the product items as the products meet, thus limiting damage due to impact between the items. 
     Flaps or doors  62  on the end of the vacuum chamber  60  nearest the packaging machine  200  provides an initial air flow barrier to air flow  52  to reduce leakage at that end. Thus, initial suction is provided to advance product  40  into the vacuum chamber  60 . Once the vacuum chamber  60  has product therein distal to aperture  115  the product  40  will block the air flow  52  from the distal end of the vacuum chamber  60  and the doors or flaps  62  are no longer required and may be moved out of the way. 
     The vacuum  100  may be adjusted for the mass of the product  40  to be advanced. For example, if the product  40  is a light and fragile cracker, the suction will not need to be as great as when the product is a sandwich type cookie having two biscuits with a cream stuffing therebetween. The sandwich cookie will have a greater mass and greater strength such that a greater suction will have to be generated by vacuum  100  to advance the product  40  into and through the vacuum chamber  60 . 
     In an alternate embodiment, a second aperture on the opposite side of the vacuum chamber  60  from aperture  115  will be connected to another vacuum hose and pump to provide additional suction. 
     When the first product item  46  is released from the release fingers  45  at the mouth of vacuum chamber  60 , it is sucked therein by the vacuum created by vacuum  100 . The vacuum chamber wall  63  preferably provides an opening large enough for air to pass around the product  40  on its way to the aperture  115 . This allows a stream of air  51  to flow from the opening of the vacuum chamber  60  and force the product  40  into the vacuum chamber  60  and move it along therein. 
     The product  40  is sucked into the vacuum chamber  60  at velocity in excess of the velocity of the conveyor belt  22  such that the product  40  is separated from the in line feeder  20  faster than it is advanced by the conveyor belt  22 , thus avoiding a pile up of product at the end of the conveyor belt  22 . The lead product item  46  is released from release finger  45  and is sucked against stop finger  70 , which extends across the face of the product such that the vacuum secures the lead product item  46  squarely against the stop finger  70 . The stop finger  70  must have a length and a flat surface area great enough to align the lead product unit  46  squarely while it is being sucked in the vacuum chamber  60 . The stop finger  70  slows the advance of the product  40  in the vacuum chamber  60 . All of the following product  40  entering the vacuum chamber  60  is squarely secured behind the previous product units  40  by dint of the vacuum in vacuum chamber  60 . When the desired length of product  40  to form a slug  44  is reached, the conveyor  22  stops advancing, and release fingers  45  hold the product  40  such that no further product units  40  pass the release finger  45 . The last released product  43  in the series is sucked into the vacuum chamber  60  and is squarely aligned with the product  40  immediately in front of it. With the flow of additional product temporarily cut off, a slug  44  of product is formed and is transported through the vacuum chamber  60 . A pushing finger  80  is now rotated into place behind the last product item  43  in the slug  44 . As the slug  44  passes the aperture  115 , the pressure gradient reverses, tending to pull the advancing slug  44  back toward the aperture  115 . However, pusher finger  80  will move the slug  44  past the aperture  115  and out of the vacuum chamber  60 . Pushing finger  80  is attached to belt  87  and has pulleys  85  at either end of the belt  87 . 
     In the embodiment shown, stop finger  70  is withdrawn from the vacuum chamber  60  distal of aperture  115  and replaced with lead finger  90  while the lead product unit  46  is under reverse vacuum pressure in vacuum chamber  60 . The lead finger  90  now defines one end of the slug  44  and will provide a support for the lead product  46  in the slug  44  to keep the product upright and square on rails  50  while being transported to the packaging machine  200 . The lead finger  90  is attached to belt  97  having pulley  95  at each end. 
     In this manner the slugs  44  are formed while the product remains transported in line. No 90 degree transports of the slugs  44  are required to form the slug  44 . The velocity of the product  40  is increased downstream of the conveyor belt  22  such that gaps can be formed between slugs  44  for introducing finger stops  70  and  80  without engaging or damaging the product  40 . 
     The fingers  70 ,  80  and  90  extend into the vacuum chamber  60  by way of slits  61  formed in the top and bottom of the vacuum chamber  60 . The slits  61  are covered by a cloth, bristle, elastomer or other pliable sealing material  64  through which fingers  70 ,  80  and  90  penetrate as they traverse the length of the slits  61 . Material  64  covering the slits  61  in the vacuum chamber  60  reduce air leakage through the slits  61  in the vacuum chamber  60 . 
     The length of the slugs  44  formed is easily adjusted by changing the distance by which conveyor belts  22 ,  24  are intermittently advanced. Changes in the slug length also require adjustments to the distances between the fingers  70  on belt  75 , the fingers  80  on belt  85  and the fingers  90  on belt  95 . The belts  75 ,  85  and  95  are driven at uniform rates relative to each other by a motor and mechanism not shown. 
     In an alternate embodiment, the conveyor belt  22  can be mounted on a movable carriage such that the carriage advances toward and retracts from the vacuum chamber  60  to deliver product with the conveyor belt  22  running at a constant speed. 
     Once out of the vacuum chamber  60 , the slugs  44  may be moved 90 degrees to feed another packaging step, or to feed an alternatively located inline packaging process. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.