Patent Publication Number: US-6341473-B1

Title: Cushioning product and machine and method for producing same

Description:
This is a Div. application of 09/186,536, filed Nov. 05, 1998, now U.S. Pat. No. 6,170,227. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to cushioning products for protecting during shipping an item packaged in a box or carton and machines for making same, and more particularly to an air pillow cushioning product and a machine for making such an air pillow. 
     BACKGROUND OF THE INVENTION 
     In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping carton or box, to fill any voids and/or to cushion the item during the shipping process. Some conventional protective packaging materials are plastic, for example expanded polystyrene, foam peanuts and starch peanuts. While these conventional materials seem to perform adequately as cushioning products, they are not without disadvantages. 
     The most serious drawback of these types of cushioning products is the mess that is tended to be made when unpacking a carton or box shipped with such loosefill as the cushioning material. The peanuts tend to be strewn about the unpacking area, requiring time intensive cleanup. Further aggravating matters, in the case of plastic peanuts, is the tendency of the plastic peanuts to cling to the item shipped in the box, to people, to clothing, to carpet and to other structures in the unpacking area, due to static electricity. 
     One proposed solution for overcoming the deficiencies of loosefill as described above is the Flo-Pak Pouch™ marketed by Free Flow Packaging International, Inc. of Redwood City, Calif. The Flo-Pak Pouch™ utilizes a cylindrical plastic sleeve which is filled with polystyrene loosefill and the ends of which are gathered and tied off to form a cylindrical shaped or “sausage” shaped bag of loosefill. While the Flo-Pak Pouch™ does prevent the mess described above caused by loosefill, it is not without its own drawbacks. For example, the Flo-Pak Pouch™ is somewhat difficult to utilize when packing articles to be shipped, as the cylindrical shaped bags do not bend easily to conform about an article within a box. Furthermore, the Free Flow Packaging machine which makes the Flo-Pak Pouch™ does not include any capability for producing a string of bags of loosefill interconnected end-to-end, i.e. the Free Flow Packaging machine has the capability for producing only individual filled bags. 
     It would be desirable to better harness such loosefill material for cushioning purposes to exploit the cushioning properties of such loosefill but at the same time to eliminate the drawback of the mess associated therewith, while at the same time solving the problems presented by the Flo-Pak Pouch™. 
     To this end, the invention disclosed in application Ser. No. 09/065,221 filed Apr. 23, 1998, assigned to the assignee of the present invention and hereby incorporated by reference herein as if fully set forth in its entirety, provides a number of cushioning products utilizing loosefill yet which avoid the prior problem of mess associated therewith, and which also provide for convenient loading of the product to be shipped into a carton therewith. One such cushioning product comprises a bag filled with loosefill packing material. The bag has a length, a width and a thickness, with the length and the width being substantially greater than the thickness. The loosefill packing material may be plastic peanuts, for example expanded polystyrene peanuts, or starch peanuts. A filled bag of loosefill according to this invention is preferably generally rectangular when viewed in side elevation and in end elevation, to promote wrapping an item to be shipped. The bag, which preferably is made of plastic, or even transparent plastic, preferably allows air to escape from it. To that end, the bag preferably includes a number of small holes therein. By allowing air to escape a “balloon” effect of the bags is avoided and the cushioning effect derives only from the cushioning qualities of the loosefill, rather than the compressability of the air within the bag and/or the elasticity of the bag. The cushioning product of that invention may also comprise a plurality of bags filled with loosefill packing material, with the bags being connected end-to-end in a string. In that case, a web of preformed and interconnected bags is provided, and loosefill packing material is inserted into the bags which are then sealed. 
     The invention of application Ser. No. 09/065,221 thus provides the cushioning qualities of loosefill, for example plastic or starch peanuts, yet without the attendant difficulties associated therewith. In addition, the preferred geometry of the bags of loosefill provide for easy insertion into a shipping box or carton as well as wrapping around the item to be shipped. 
     One limitation of the invention of application Ser. No. 09/065,221, however, is that the length of the cushioning product is not readily varied since the length of the cushioning product is dependent upon the length of the preformed interconnected bags which are purchased in web form and loaded onto the machine in a roll. It would be desirable to be able to vary the length of cushioning product produced without having to remove the existing roll of bags of one length and replacing that roll of bags with another roll of bags of the desired length. 
     Another feature of the invention of application Ser. No. 09/065,221 is the provision of loosefill for filling the bags to provide cushioning capability. In some applications it might be desirable to do away with the loosefill if an acceptable cushioning product can still be produced. 
     One attempt at eliminating the web of preformed and interconnected bags in forming a product containing bag has been made by Dibipack of Italy. The Dibipack machine uses a sheet of plastic film which is unrolled off of a roll, is formed into a cylindrical container, is filled with product and is then sealed. That machine comprises a frame, a plastic sheet supply assembly mounted on the frame, a forming assembly mounted on the frame downstream of the plastic sheet supply assembly which forms the plastic sheet into a tube with the lateral edges of the plastic sheet overlapping, a pulling assembly mounted on the frame downstream of the forming assembly which pulls the plastic sheet from the plastic sheet supply assembly to and over the forming assembly, a first heat sealing assembly mounted on the frame downstream of the forming assembly which heat seals the overlapping lateral edges of the tube together, and a second heat sealing assembly mounted on the frame downstream of the first heat sealing assembly which transversely heat seals the tube at each end of the longitudinal heat seal formed by the first heat sealing assembly. This machine is limited, however, in that the first heat sealing assembly is comprised of a fixed length heat sealing bar which is movable into and out of contact with the overlapping lateral edges of the tube to longitudinally heat seal the overlapping lateral edges. Thus, a user is limited to the length of bag capable of being produced on this machine to multiples of the length of this longitudinal heat sealing bar. Stated differently, this machine provides no capability of forming a desired length of bag other than in a length equal to the length of the longitudinal heat sealing bar or multiples thereof. 
     SUMMARY OF THE INVENTION 
     The present invention is a machine for producing cushioning product which allows a user to select a length of product to be produced from a continuous plurality of selectable lengths. A user is not limited to the length of preformed interconnected bags, nor to the length of the longitudinal heat sealing bar and multiples thereof, as determining the length of cushioning product to be formed. 
     In one aspect of the present invention, a machine for producing cushioning product comprises a frame, a plastic sheet supply assembly mounted on the frame, a forming assembly mounted on the frame downstream of the plastic sheet supply assembly which forms the plastic sheet into a tube with the lateral edges of the plastic sheet overlapping, a pulling assembly mounted on the frame downstream of the forming assembly which pulls the plastic sheet from the plastic sheet supply assembly to and over the forming assembly, a first heat sealing assembly mounted on the frame downstream of the forming assembly which is selectively activatable to longitudinally heat seal the overlapping lateral edges of the tube together a selected length from a continuous plurality of selectable lengths, and a second heat sealing assembly mounted on the frame downstream of the first heat sealing assembly which transversely heat seals the tube at each end of the longitudinal seal formed by the first heat sealing assembly to thereby form an air pillow. 
     The forming assembly preferably comprises in combination a cylinder and a collar, the collar transitioning the plastic sheet from a generally planar configuration as the sheet is pulled off of the plastic sheet supply assembly to a generally cylindrical configuration about the cylinder. 
     The pulling assembly preferably comprises a pair of drive belts, one belt of the pair of belts being located on each lateral side of the tube, and each of the pair of drive belts drivingly engaging the tube. 
     The first heat sealing assembly preferably comprises a heated wheel which is selectively movable into and out of contact with the overlapping lateral edges of the tube to heat seal the tube overlapping lateral edges together. 
     The second heat sealing assembly preferably comprises a pair of heated movable bars, positioned transversely of the longitudinal axis of the tube, and which are movable from an inoperative position spaced apart fore and aft of the tube to an operative sealing position wherein the bars are moved together such that the fore and aft wall portions of the tube are heat sealed together. 
     The present invention also provides a method of making a cushioning product, as well as a cushioning product made by the method. The method comprises providing a plastic sheet with lateral edges, forming the plastic sheet into a tube with the lateral edges of the plastic sheet overlapping, selecting a length from a continuous plurality of selectable lengths along which to longitudinally heat seal the overlapping lateral edges of the tube together, longitudinally heat sealing the overlapping lateral edges of the tube together the selected length, and transversely heat sealing the tube at each end of the longitudinal heat seal to thereby form an air pillow. 
     The major advantage of the present invention is that a user may readily vary the length of cushioning product produced. The user is not limited to any predetermined bag length as when a web of such preformed bags is utilized, nor is a user limited to a discrete length by the length of a longitudinal heat sealing bar and multiples thereof. Rather, a supply of plastic sheet is fed into the machine of the present invention which has the capability of producing air pillows of continuously variable lengths. In addition, as the machine of the present invention produces sealed air pillows, loosefill is not required as the cushioning qualities of the air itself can be exploited. However, if desired, the peanut dispensing portion of the machine of application Ser. No. 09/065,221 can be incorporated into the machine of the present invention to produce a bag or a string of interconnected bags of loosefill packing material. 
     These and other advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the machine of the present invention; 
     FIG. 2 is a front elevation view of the machine of FIG. 1; 
     FIG. 3 is a side elevation view of the machine of FIGS. 1 and 2; 
     FIG. 4 is a view taken along line  4 — 4  of FIG. 2; 
     FIG. 5 is a block diagram of the operation of the machine of FIGS. 1-4; and 
     FIG. 6 is a perspective view of the machine of FIGS. 1-5 in combination with the peanut dispensing portion of the machine of application Ser. No. 09/065,221. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to FIGS. 1-3, there is illustrated a machine  10  for producing cushioning product according to the present invention. The machine  10  includes a machine frame  12 . A plastic sheet supply assembly  14  is mounted on the frame  12  and supplies a sheet of plastic film  16  to a forming assembly  18 . Alternatively, the plastic sheet supply assembly  14  could be mounted on a separate cart which is dockable to or otherwise usable with the frame  12 . Thus, the term “frame” is intended to embrace all such variations. The forming assembly  18  is mounted on the frame  12  downstream of the plastic sheet supply assembly  14 . It forms the plastic sheet  16  into a tube  20 , for example a cylindrical tube  20 , with the lateral edges  22  and  24  of the tube  20  overlapping as at  26  (FIG.  4 ). 
     More particularly, the forming assembly  18  comprises in combination a forming tube, e.g. forming cylinder  30 , and a forming collar  32 , though the invention is not limited to any such combination or illustrated geometries of tube and collar. The cylinder  30  is mounted to the upper end of the machine frame  12  via a support  34 , and it extends downwardly into the machine  10  as is shown in FIG.  2 . The collar  32 , also known as a film forming “shoe,” is likewise mounted to the upper end of the frame  12 . Clearance is provided between the cylinder  30  and the radially inner edges  36  of the collar  32  to allow the plastic sheet  16  to pass over the collar  32  downwardly and around the cylinder  30 . The cylinder  30  and collar  32  thus form the plastic sheet  16 , which is in a generally planar configuration as it is pulled off of the plastic sheet supply assembly  14 , into a generally cylindrical, tubular configuration about the cylinder  30 . 
     As best seen in FIGS. 2-4, a pulling assembly  40  is mounted on the frame  12  downstream of the forming assembly  18 . The pulling assembly  40  pulls the plastic sheet  16  from the plastic sheet supply assembly  14  to and over the forming assembly  18 . More particularly, the pulling assembly  40  comprises a pair of drive belts  42  and  44 , one belt of the pair  42 ,  44  of belts being located on each lateral side of the cylinder  30  and hence on each lateral side of the cylindrically configured plastic tube  20 . Belt  42  passes over a driven roller  50  and idler rollers  52 ,  54  and  56 . Likewise, belt  44  passes over a driven roller  60  and idler rollers  62 ,  64  and  66 . The rollers  50 ,  52 ,  54 ,  56  and  60 ,  62 ,  64  and  66  are rotatably mounted to a pair of brackets  51  and  53  respectively which themselves are mounted to a vertical plate  55  forming a part of machine frame  12 . All the rollers  50 ,  52 ,  54 ,  56 ,  60 ,  62 ,  64  and  66  are preferably fabricated of Delrin. 
     Referring to FIG. 3, it will be seen that the driven roller  50  is driven by a motor  70  mounted to a motor mounting plate  72  by upper and lower motor mounting brackets  74  and  76  respectively. The motor  70  is connected to the driven pulley  50  through a coupling  78 , gear  80  and bearing  82 . Gear  80  drives a similar gear (not shown for clarity) mounted to a shaft (also not shown for clarity) on which driven roller  60  is also mounted. Thus, motor  70  drives both driven rollers  50  and  60 . 
     An optical encoder  84  is mounted on the drive shaft  86  of the motor  70 . The encoder  84  registers or indicates the rotation of the shaft  86  and hence the rotation of the driven rollers  50  and  60 , and sends pulse signals to a microprocessor (not shown in FIG. 3) programmed to relate those signals to the linear amount of plastic sheet advanced in tubular, cylindrical form  20  by the drive belts  42 ,  44 . 
     Referring now to FIGS. 2-4, there is illustrated a first heat sealing assembly  90 . This assembly  90  includes a heat sealing wheel  92  preferably fabricated of brass including sealing edge  94  and outboard insulating disks or rings  95  preferably fabricated of glass-filled phenolic. The wheel  92  is rotatably mounted on a shaft  96 , preferably fabricated of bronze, including a heater  98  imbedded therein and including leads  100 ,  102  for connection to an electricity supply. Shaft  96  is secured on each end to one end of a dog leg link  110  which is pivoted at  112  to a bracket  114  mounted to the frame  12 . The other end of dog leg link  110  is connected to the piston  120  of a pneumatic piston and cylinder  122  mounted to the bracket  114 . 
     Referring now to FIGS. 2 and 3, at the lower end of the machine  10  there is illustrated a second heat sealing assembly  140 . This assembly  140  comprises a pair  142 ,  144  of heated movable bars. The bars  142 ,  144  are positioned transversely along the longitudinal axis of the cylinder  30  and hence transversely of the cylindrically formed plastic tube  20 . The bars  142 ,  144  are movable by way of a pneumatic cylinder  146  from an inoperative position spaced apart fore and aft of the tube  20  to an operative sealing position wherein the bars  142 ,  144  are moved together such that the fore and aft wall portions  20   a  and  20   b  respectively of the tube  20  are heat sealed together. 
     Preferably, the bars  142  and  144  include separate upper  150 , lower  152  and intermediate  154  heater elements. Element  150  forms the bottom heat seal of an upper air pillow  160 . The lower element  152  forms the upper heat seal of a lower air pillow  162 . The intermediate element  154  melts completely through the plastic sheet to separate the upper and lower air pillows  160 ,  162 . In the event that a string of interconnected air pillows is desired to be produced, rather than individual air pillows, the machine  10  would preferably include a means for selectively activating and deactivating the intermediate element  154  as desired. Alternatively, the element  154  could be replaced with a selectively activatable blade to sever adjacent air pillows. 
     Referring back to FIG. 1, a control box  170  houses the associated electrical (e.g. microprocessor) and pneumatic controls for the machine  10 . A keypad  172  with display  174  allows a user to input the desired length of air pillow to be formed, as well as the desired number of pillows to be formed. A cycle start button  176  activates the machine  10 , whereas an emergency stop button  178  stops the machine  10  in the event of an emergency. Temperature dials  180  and  182  control the temperature of the heat sealing wheel  92  and heat sealing bars  142 ,  144  respectively. Control  184  is provided for turning power to the machine  10  on and off. 
     In use, a user inputs the length of air pillow desired (e.g., 10 inches, 12 inches, etc.), along with the number of air pillows desired, via the keypad  172  and verifies same with the display  174 . The temperatures are adjusted with the dials  180  and  182  (heat sealing wheel  92  preferably being set at 380° F. and heat sealing bars  142 ,  144  preferably being set at 390-400° F.) and then the start button  176  is depressed. Simultaneously, air cylinder  122  retracts moving heating wheel  92  into contact with the overlapped portion  26  of the cylindrically formed plastic tube  20 , and the motor  70  is started thus driving belts  42  and  44  pulling the plastic sheet  16  off of the plastic sheet supply  14  and over the collar  32  and around the cylinder  30 . Heating wheel  92  is rotated solely by the advancing cylindrically formed plastic tube  20 . When the heat wheel  92  has formed a longitudinal heat seal along the overlapped portion  26  corresponding to the desired length of the air pillow entered via the keypad  172  (as monitored by encoder  84  and the microprocessor), simultaneously the pneumatic cylinder  122  extends thus pivoting the wheel  92  away from and out of contact with the overlapped portion  26 , and the motor  70  is stopped. While the now longitudinally sealed cylindrical plastic tube  20  is stationary, the second heat sealing assembly  140  is activated once to form the lower seal of the air pillow being formed. Then, again, simultaneously, air cylinder  122  retracts moving heating wheel  92  back into contact with overlapped portion  26 , and motor  70  is started causing the belts  42  and  44  to advance the plastic tube  20  downwardly. Once a second like length of longitudinal heat seal has been formed, the motor  70  is again stopped, cylinder  122  again extends pivoting heat wheel  92  away from overlapped portion  26  and the second heat sealing assembly  140  is activated a second time to form the upper seal of the air pillow being formed. The cycle is repeated until the desired number of air pillows of the desired length have been produced, at which time operation of the motor  70  ceases, cylinder  122  is moved to and remains in the extended position, and bars  142 ,  144  are moved to and remain in their spaced apart positions, the machine  10  awaiting input of the next command via the keypad  172 . A block diagram of the operation of the machine  10  is illustrated in FIG.  5 . 
     The plastic sheet  16  is preferably 0.0015 inches thick and is preferably of the type available from AEP Industries, Inc. of Hackensack, N.J. as part number 11CFPPF or 26FLPPF. Collar or shoe  30  is preferably of the type available from Former Tech, Inc. of Austin, Tex. as part number FBS-500. Belts  42  and  44  are perfectly of the type available from Burrell-Leder, Inc. of Skokie, Ill. as part number 802-06-013/B-13905. Motor  70  is preferably a Dayton 1/15 hp, 115V, 100 rpm, 27 in-lb gear motor available from Grainger of Addison, N.J. as part number ZZ803D. Coupling  78  is preferably a 3-jaw coupling available from Boston Gear of Boston, Mass. as part number BF10. Gear  80  is preferably a cast iron stock spur gear, 14½° pressure angle, 9″ pitch diameter available from Martin Sprocket and Gear of Arlington, Tex. as part number C1090. Bearing  82  is preferably of the type available from Nice Bearing Co. and distributed by Motion Industries of Chicago, Ill. as part number R12ZZ. Encoder  84  is preferably of the type available from Monroe Machine and Design, Inc. of Jamesburg, N.J. as part number 802-05-011. Heater  98  is preferably a ½ inch O.D., 2½ inches long, 300 Watt, 120V unit available from Watlow Corp. of Columbia, Md. Cylinder  120  is preferably of the type available from Bimba, Inc. of Monee, Ill. as part number 022-RP. Heat sealing assembly  140  is preferably of the type available from Monroe Machine And Design, Inc. of Jamesburg, N.J. as part number 802-06-012. The speed of the cylindrically formed plastic sheet film is variable with motor  70  up to a speed of 471 inches per minute; the preferred speed is 400-430 inches per minute. 
     Those skilled in the art will readily recognize numerous adaptations and modifications which can be made to the present invention which will result in an improved cushioning product and machine, yet all of which will fall within the spirit and scope of the present invention as defined in the following claims. For example, and as discussed above, the machine of the present invention could be combined with the peanut dispensing portion of the machine of application Ser. No. 09/065,221 to produce a bag or a string of interconnected bags of loosefill packing material. See FIG.  6 . In that case the film or sheet would need to be porous or otherwise include holes, slits or perforations therein to allow air to escape from the bag to avoid a “balloon” effect. Further, film or sheet other than plastic film may be used with the machine of the invention. For example, biodegradable starch-based film may be used; the only requirement is that the film be heat fusable or heat weldable. In such a case starch peanuts could be used to fill the bags made from starch-based film to produce a biodegradable cushioning product. Still further, the bags formed by the present invention could be used to contain product other than cushioning product, for example food items, hardware items, medical supplies or any other type of consumer product which is typically packaged in such a bag. Accordingly, the invention is to be limited only by the scope of the following claims and their equivalents.