Sack filling method and apparatus

Abstract

A method and apparatus for filling sacks with a predetermined quantity of product. The apparatus comprises at least one mobile sack feed and filling unit which carries each sack along the process line and at the same time fills the product into it. In the method according to the invention, the empty sacks are fed at the same speed as the mobile filling unit before they are transferred to the mobile filling unit itself.

What is claimed is:  
     
         1 . A method for filling sacks with products of different kinds, in particular, powdery or granular products, wherein the sacks are filled while they are being fed forward.  
     
     
         2 . A method for transferring sacks to sack feed means in a sack filling apparatus, wherein the sacks are transferred to the feed means while they are being fed forward.  
     
     
         3 . The method according to  claim 2 , wherein the sacks are made to travel at the same speed as the feed means before they are transferred to the feed means.  
     
     
         4 . The method according to any of the foregoing claims, wherein the sack feed means follow a circular feed path.  
     
     
         5 . The method according to any of the foregoing claims, wherein the means for transferring the sacks to the feed and filling means follow a linear path which, at the zone where the sack is transferred, is substantially tangent to the circular path followed by the feed means; the transfer means, when they are at the sack transfer zone, traveling at the same tangential speed as the feed and filling means.  
     
     
         6 . The method according to any of the foregoing claims, wherein the sacks follow an angular path through approximately 270°.  
     
     
         7 . The method according to any of the foregoing claims, wherein the sacks are filled within an angular interval that does not exceed 90° 
     
     
         8 . A method for transferring sacks to sack sealing means in a sack filling apparatus, wherein the sacks are transferred to the sealing means by the feed and filling means without stopping the feed and filling means.  
     
     
         9 . The method according to  claim 8 , wherein, as the sacks are transferred to the sealing means by the feed means, they move in a substantially linear direction tangent to the circular path along which the sacks themselves were previously fed by the feed and filling means.  
     
     
         10 . The method according to any of the foregoing claims, wherein the sacks are fed forward on means that support them at an adjustable height.  
     
     
         11 . An apparatus for filling sacks with a predetermined quantity of product, especially a granular or powdery product, the apparatus being equipped with means for feeding the sacks, means for transferring the sacks to the feed means and means for filling the sacks, the apparatus comprising at least one mobile unit for feeding and filling a corresponding sack, the mobile unit comprising means that support means for gripping and holding the sack and means for filling the sack; means also being provided to feed the mobile unit along a defined path.  
     
     
         12 . The apparatus according to  claim 11 , comprising a plurality of mobile units for feeding and filling the sacks.  
     
     
         13 . The apparatus according to  claim 11  or  12 , wherein the mobile units for feeding and filling the sacks follow a circular feed path.  
     
     
         14 . The apparatus according to any of the foregoing claims from  11  to  13  or according to the preamble to  claim 11 , wherein the means for transferring the sacks comprise means which support means for gripping and releasing the sacks, said support means being driven at the same speed as the mobile feed and filling units to enable the sack to be transferred to the corresponding feed and filling unit itself.  
     
     
         15 . The apparatus according to any of the foregoing claims from  11  to  14 , wherein the means for transferring the empty sack to one of the mobile feed and filling units follow a path that presents at least one section extending in a direction substantially tangent to the path followed by the sack holding means of the mobile filling unit.  
     
     
         16 . The apparatus according to any of the foregoing claims from  11  to  15 , wherein the mobile units for feeding and filling the sacks are mounted on a rotating mounting frame.  
     
     
         17 . The apparatus according to any of the foregoing claims from  11  to  16 , wherein the filling means on the mobile unit comprise a filler pipe which discharges the product into the sack.  
     
     
         18 . The apparatus according to any of the foregoing claims from  11  to  17 , wherein each mobile feed and filling unit comprises means for supporting the bottom of the sack, said means being adjustably mounted for height so as to adapt to sacks of different sizes or heights.  
     
     
         19 . The apparatus according to any of the foregoing claims from  11  to  18 , wherein each mobile feed and filling unit comprises means for stopping the bottom of the sack, said means being adjustably mounted for height so as to adapt to sacks of different sizes or heights.  
     
     
         20 . The apparatus according to any of the foregoing claims from  11  to  19 , wherein the mounting frame of the mobile feeding and filling units comprises a rotatable, vertically fixed upper section and a lower section that can be adjusted in height relative to the upper section and that is operatively connected to, and rotatable with, the latter, the means for supporting the bottoms of the sacks and/or the means for stopping the bottoms of the sacks being mounted on the frame lower section.  
     
     
         21 . The apparatus according to any of the foregoing claims from  11  to  20 , wherein the mobile filling unit comprises at least one upper hopper that moves together with the mobile filling unit and has a lower opening for discharging the product into a corresponding filler pipe and an upper opening for receiving the product.  
     
     
         22 . The apparatus according to  claim 21 , wherein the upper opening in the hopper communicates with a hole made in a fixed upper flange and is elongated in the direction opposite the feed direction so that a sufficient quantity of product to completely fill the sack can be discharged into the hopper.  
     
     
         23 . The apparatus according to any of the foregoing claims from  11  to  22 , wherein each mobile feed and filling unit comprises suction means for opening the top of the sack.  
     
     
         24 . The apparatus according to any of the foregoing claims from  11  to  23 , or according to the preamble to  claim 11 , further comprising a longitudinal section that extends along one side of the filling section and that is designed to seal the top of the sack and feed the sack out of the apparatus.  
     
     
         25 . The apparatus according to  claim 24 , wherein the sacks are transferred to the sealing means by the feed and filling means without stopping the feed and filling means.  
     
     
         26 . The apparatus according to  claim 24  or  25 , wherein, as the sacks are transferred to the sealing means by the feed and filling means, they move in a substantially linear direction tangent to the circular path along which the sacks themselves were previously fed by the feed and filling means.  
     
     
         27 . The apparatus according to any of the foregoing claims from  11  to  26 , wherein the apparatus mounting means comprise a fixed frame that rotatably mounts the frame which mounts the mobile filling units.  
     
     
         28 . The apparatus according to any of the foregoing claims from  11  to  27 , wherein the lower mobile frame section comprises a central shaft and a plurality of radial arms that support the lower sections of the mobile filling units.  
     
     
         29 . The apparatus according to any of the foregoing claims from  11  to  28 , further comprising means for guiding the circular motion of the frame.  
     
     
         30 . The apparatus according to  claim 29 , wherein the means for guiding the circular motion of the frame comprise a circular surface which slidably engages an outside surface of a central column that mounts a plate which supports the mobile feed and filling units.  
     
     
         31 . The apparatus according to any of the foregoing claims from  11  to  31 , wherein the means for guiding the circular motion of the frame comprise a vertical rod extending downwardly from the central shaft that mounts the bottom section of the mobile frame.  
     
     
         32 . The apparatus according to any of the foregoing claims from  11  to  31 , wherein, seen from above, the apparatus has a substantially L-shaped configuration.  
     
     
         33 . The apparatus according to any of the foregoing claims from  11  to  32 , wherein, to transfer the full sack to the sack sealing means, the sack gripping means of the corresponding mobile unit release the upper edge of the sack sequentially as they reach the sack receiving means of the sealing means.