Patent Application
20050126126
1. Field of the Invention
The invention relates to a container configured to hold a plurality of articles, and, more particularly, to a radially flexible container with means to hold the contents so that a blow or acceleration will not damage the contents.
2. Description of the Related Art
Articles can be contained and transported in flexible containers such as bags. It can be desirable to limit the movement of individual articles in the flexible container with respect to one another to reduce the likelihood that articles will be damaged and to increase the likelihood that the container will maintain a relatively rigid shape. Several different methods have been proposed to limit the movement of individual articles in the flexible container with respect to one another. For example, it is known to fill a flexible container and shrink-wrap the filled container. It is known to draw air from the flexible container to define a vacuum, wherein the vacuum seal can substantially limit the movement of articles in the container with respect to one another. It also is known to compress a filled, flexible container with pressurized air to urge air from the flexible container and substantially limit movement of articles in the container with respect to one another.
The present inventors previously made invention of a Transportable Container for Bulk Goods and Method for Forming the Container, U.S. Pat. No. 6,494,324. A radially flexible container is filled with a filling system and the diameter of the container is reduced at the fill level as the fill level rises.
The subject invention provides an improvement over the prior diameter reducing system wherein the container is shrunk at the fill level by heat shrinking. A heater can be positioned adjacent the fill level to direct heat at the container to shrink the container at the fill level. A large diameter of the container receives particles and the container is shrunk at the fill level to a smaller fill diameter. Shrinkage of the container generates hoop forces and promotes controllable contact between particles.
Accordingly, the subject invention provides an alternative to stretch wrap to reduce the diameter of the container. The amount of material required to package particles is reduced by the elimination of stretch wrap. The amount of waste material from used packaging material is reduced by the elimination of stretch wrap.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
Throughout the present specification and claims the phrase fill material is used as a shorthand version of the wide range of products that can be packaged utilizing the present invention. The terms fill material, articles, and particles can be used interchangeably. The present invention finds utilization in packaging any material that is packaged. These items can encompass large bulk packaged pieces as well as very small bulk packaged pieces. Examples of smaller fill materials include, but are not limited to, the following: agricultural products like seeds, rice, grains, vegetables, fruits; chemical products like fine chemicals, pharmaceuticals, raw chemicals, fertilizers; plastics like plastic resin pellets, plastic parts, rejected plastic parts, machined plastic parts; cereals and cereal products such as wheat; a variety of machined parts of all sorts; wood products like wood chips, landscaping material, peat moss, dirt, sand, gravel, rocks and cement. The present invention also finds utilization in bulk packaging of larger fill material including, but not limited to: prepared foods; partially processed foods like frozen fish, frozen chicken, other frozen meats and meat products; manufactured items like textiles, clothing, footwear; toys like plastic toys, plastic half parts, metallic parts, soft toys, stuffed animals, and other toys and toy products. All of these types of materials and similar bulk packaged materials are intended to be encompassed in the present specification and claims by this phrase.
The present invention can be applied in combination with any of the features disclosed in U.S. Pat. No. 6,494,324, which is hereby incorporated by reference in its entirety. Some of the features disclosed in U.S. Pat. No. 6,494,324 that can be applied in combination with present invention are described briefly below.
Referring now to
The reduction of the large diameter 16 at the fill level 18 by shrinking the container 12 at the fill level 18 generates hoop forces which apply a gentle squeeze to the fill material 14, helping to support and firm it. The hoop forces stabilize the fill material 14 by promoting controllable contact between the elements of the fill material 14 being loaded into container 12, thereby promoting bridging between the components of the fill material 14. For example, when the fill material 14 being loaded is a bulk cereal in puff or flake form, hoop forces promote bridging between cereal pieces, thereby reducing the relative motion between the pieces and immobilizing the cereal within container 12. By adjusting the extent of shrinkage, hoop forces can be tailored to the type of fill material 14 being inserted in container 12. Hoop forces allow for a very compact and rigid container, which does not allow the fill material 14 to shift or get crushed within container 12. The container 12 is filled without any internal frame or support means, since the subsequent removal of such a frame or support means would result in the hoop forces being dissipated and also cause dislodging of the fill material 14 which may result in some of the fill material 14 being crushed.
A process performable by an embodiment of the present invention is illustrated in the simplified flow diagram of
After step 36, the process continues to step 42 and the support 52 is positioned at a particle receiving station 44. The support 32a can be moved between the container receiving station 34 and the particle receiving station 44 with a motor 46. The motor 38, shown in
The process continues to step 48 and the heater 24 can be positioned with respect to the flexible container 12. The heater 24 can be complementarily shaped with respect to the flexible container 12. For example, the container 12 can be cylindrical and the heater 24 can be a ring for receiving the flexible container 12. The heater 24 can encircle the fill level 18.
The process continues at step 50 and a plurality of particles 14 can be transferred to the container 12. The particles 14 can be transferred to the container 12 with a filling system including a conveyor 52. The particles 14 move along the conveyor 52 and can drop through a passage 54 defined by the support 32a. A controller 56 can control the conveyor 52 to move particles 14 to the container 12. As shown in
Step 58 monitors whether the fill level 18 has changed. The fill level 18 can be sensed by a sensor 60. The sensor 60 can be an infrared sensor. The invention can include an infrared sensor emitter array 62 supporting a plurality of infrared emitters 64 along on a path extending parallel to the vertical axis of the container 12. Each emitter 64 can emit infrared radiation substantially traverse with respect to the vertical axis of the container 12. The sensor 60 can be horizontally aligned with at least one of the plurality of infrared emitters 64 during filling of the container 12. When the fill level changes, infrared radiation communicated between the emitter 64 and the sensor 60 can be blocked by the particles 14. In response to a change in the fill level, the sensor 60 can emit a signal to the controller 56. The controller 56 can control a motor 66 to vertically move the sensor 60 so that the sensor 60 can receive infrared radiation from one of the plurality of emitters 64. To enhance the clarity of
In alternative embodiments of the invention, the sensor 60 can include an ultrasonic transmitter and receiver, applying sound waves to monitor the fill level 18 of the material 14 in the container 12. In another embodiment, a lower support member, such as support member 25 shown in
For certain types of fill material 14 it can be advantageous to settle the fill material 14 as the flexible container 12 is being filled. To accomplish this, the support member 25 can include a vibratory shaker thereby permitting the support member 25 to settle the fill material 14 as the container 12 is being filled.
In alternative embodiments of the invention, the support member 25 is vertically movable. In such embodiments, during the initial stages of filling the container 12, the support member 25 is placed at a position very close to the conveyor 70. As the container 12 fills, the support member 25 is moved away from the conveyor 70, in a downward direction, to accommodate the accumulation of fill material 14 in the container 12. The advantage of this system is that fragile materials have a shorter distance to drop from the conveyor 70 into the container 12. Movement of the support member 25 can be accomplished by any of a variety of mechanisms including scissors platform legs, hydraulic pistons, pneumatic pistons, or a geared mechanism.
As used herein, the fill level is the highest level at which particles substantially occupy an entire cross sectional area of the container 12. The plurality of particles can define a crest 68 and the fill level 18 can be below the crest 68. The fill level can be twelve inches from the crest 68. Communication between the sensor 60 and a corresponding emitter 64 can be blocked by the crest 68. The sensor 60 can be spaced from the heater 24 a distance substantially similar to the distance between the crest 68 and the fill level 18.
If the fill level has not changed in step 58, the process returns to step 50 and a plurality of particles are transferred to the container 12. If the fill level has changed, the process continues to step 70 and the extent of filling of the container 12 is monitored. If the container 12 is full, the process ends at step 72. If the container 12 is not full, the process continues to step 74 and the heater 24 is positioned adjacent the fill level 18. The heater 24 can be moved along the container 12 with the motor 66. The motor 66 can move along a path extending substantially parallel to the vertical axis of the container 12.
Alternatively, as shown in
After the heater 24 is positioned adjacent the fill level 18 at step 74, heat 26 can be directed adjacent the fill level 18 at step 76. Heat 26 can be directed to the fill level 18 to shrink the large diameter 16 of the container 12 to the fill diameter 20 at the fill level 18. The controller 56 can control the heater 24 to continuously emit heat 26 or selectively emit heat 26. The heater 24 can be selectively controlled to control the amount of heat 26 directed to the fill level 18. The amount of heat 26 can be controlled to control the extent or degree of shrinkage of the container 12. Shrinkage of the container 12 can generate hoop forces to stabilize the plurality of particles 14 and promote controllable contact between the individual particles. In a preferred embodiment, the hoop forces generated are approximately 1-3 lbs. per square inch. Shrinkage of the container 12 can be relatively gentle to bring individual particles into engagement with respect to one another. At any particular cross-section, the engaged particles can form a lattice reducing the likelihood of movement of the particles relative to one another and enhancing the structural rigidity of the container 12. Engagement between particles resulting from the application of hoop force at the fill level as the fill level rises can also reduce the likelihood that a blow or acceleration will damage the particles. After heat 26 is directed adjacent the fill level 18 at step 78, the process continues to step 50 and a plurality of particles 14 are transferred to the container 12.
Referring now to
The top of the container 12 can be closed or left open after filling depending on the fill material. For example, certain fill material 14 such as wood chips, sand, gravel, and other fill material 14, may not require that the open top be closed. The open top can be closed in any of a variety of manners known in the art including, but not limited to: sonic or heat welding of open top, closure of open top with a plastic pull tie, closure of open top with wire or rope, closure of open top with a clamp, and other closure means known in the art. In embodiments where continuous tubular rolls and sonic or heat welding of the open top are used, the process of sealing the top of one container 12 can also create the bottom of the next container 12.
It may be advantageous that once the container 12 has been filled with fill material 14 to include the additional step of placing a nylon strap netting over the container 12. The netting may include a series of loops either at the top or the bottom of the netting to enable the resulting load to handle like a Super Sack®. Moving the unit with the loops rather than the pallet or bottom support would be advantageous in loading cargo ships with a very stable load with the least amount of cost associated with packaging material.
The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and do come within the scope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims.
