Light-tight film package

Information

  • Patent Grant
  • 6588592
  • Patent Number
    6,588,592
  • Date Filed
    Friday, July 20, 2001
    23 years ago
  • Date Issued
    Tuesday, July 8, 2003
    21 years ago
Abstract
A package for enclosing a plurality of sheets. The package comprises a pouch adapted to receive the plurality of sheets, a leader, and a closure member. The pouch comprises a leading end and a trailing end opposite the leading end. The trailing end is open to receive the plurality of sheets. The trailing end is folded back at least once to form a closure flap to light-tightly close the pouch. The leader is disposed at the leading end of the pouch and is folded back onto the pouch. The closure member includes a first end affixed to the leader, a second end affixed to the closure flap, and a rupturable portion disposed adjacent the first end. When the rupturable portion is ruptured, the first end separates from the closure member and adheres to leader while the remaining portion of the closure member adheres to the closure flap by the second end.
Description




FIELD OF THE INVENTION




The present invention relates generally to a film package, and more particularly to a package for storing a plurality of sheet film therein.




BACKGROUND OF THE INVENTION




Sheets of material, such as paper and film, are generally packaged for sale and/or transport. If the sheet material is comprised of a photosensitive material, such packaging needs to be light-tight so as to not adversely affect the photosensitive characteristics of the sheet material prior to use.




For example, radiation image films are widely used in the medical field for photographing objects such as human bodies with x-rays for medical diagnosis. The x-ray film sheets are stored in a magazine or cassette and taken out one-by-one by a sheet delivery system. Such x-ray sheet film is photosensitive, so the packaging for sale and/or transport must be light-tight.




Further, when loading the x-ray film sheets into the magazine, they must not be exposed to extraneous light. Accordingly, it had been general practice to load the sheet film into the magazine or cassette (or other package receiving device) in a dark room. However, since the efficiency of such a loading process is low, there is a demand for loading x-ray sheet film in a day-light or room-light (i.e., ordinary light) environment/conditions.




Various methods have been proposed for light-tight packages for loading x-ray film sheets in a room light environment. Examples of x-ray film packages and light-tight film sheet packages are disclosed in U.S. Pat. No. 5,251,755 (Kausch) commonly assigned and incorporated herein by reference, U.S. Pat. No. 4,909,389 (Plessers et al.), U.S. Pat. No. 5,008,694 (Tajima et al), U.S. Pat. No. 3,741,386 (Schmidt) and U.S. Pat. No. 4,933,696 (Schmidt et al.).




While such apparatus may have achieved certain degrees of success in their particular applications, a need continues to exist for a robust light-tight film sheet package which can be readily loaded in a magazine/cassette in day-light conditions while not adversely affecting any photosensitive characteristics of the film sheets.




Accordingly, a need continues to exist for a light-tight package adapted to be loaded into a package receiving device while maintaining light integrity.




SUMMARY OF THE INVENTION




An object of the present invention is to provide a light-tight film sheet package.




Another object of the invention is to provide such a light-tight package which can be loaded into a package receiving device in room light conditions.




These objects are given only by way of illustrative example. Thus, other desirable objectives and advantages inherently achieved by the disclosed invention may occur or become apparent to those skilled in the art. The invention is defined by the appended claims.




According to one aspect of the invention, there is provided a package for enclosing a plurality of sheets. The package comprises a pouch adapted to receive the plurality of sheets, a leader, and a closure member. The pouch comprises a leading end and open along a trailing end opposite the leading end to receive the plurality of sheets. The trailing end is folded back at least once to form a closure flap to light-tightly close the pouch. The leader is attached to the pouch at the leading end and is folded back onto the pouch. The closure member includes a first end affixed to the leader, a second end affixed to the closure flap, and a rupturable portion disposed adjacent the first end. When the rupturable portion is ruptured, the first end separates from the closure member and adheres to leader while the remaining portion of the closure member adheres to the closure flap by the second end.




According to another aspect of the present invention, there is provided a package for enclosing a plurality of sheets comprising a pouch, a leader, and at lease one closure member. The pouch is adapted to receive the plurality of sheets, and comprises a leading end and a trailing end opposite the leading end. The pouch is open along the trailing end to receive the plurality of sheets, with the trailing end being folded back at least once to form a closure flap to light-tightly close the pouch. The leader is disposed at the leading end of the pouch and folded back onto the pouch. The at least one closure member includes a first end, a second end, a top side, and a bottom side, a first attachment area disposed at the first end on the bottom side, a second attachment area disposed at the second end on the bottom side, a non-attachment area disposed on the bottom side intermediate the first and second attachment areas, an adhesive disposed on the first and second attachment areas, and a rupturable portion disposed at the first end adjacent the first attachment area. The first attachment area is adhered to the leader. The second attachment area is adhered to the closure flap, such that when the rupturable portion is ruptured, the first end separates from the closure member and adheres to the leader at the first attachment area and the remaining portion of the closure member adheres to the closure flap at the second attachment area.




The present invention provides a light-tight package adapted to be loaded into a package receiving device in room light conditions.











BRIEF DESCRIPTION OF THE DRAWINGS




The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.





FIG. 1

shows a perspective view of a stack of film sheets being loaded into a package.





FIG. 2

shows a perspective view of the package of

FIG. 1

with the stack of film sheets loaded within and one end open.





FIG. 3

shows a perspective view of the package of

FIG. 2

with the open end folded.





FIG. 4

shows a perspective view of the package of

FIG. 3

with the open end further folded to form a closure flap.





FIG. 5

shows a perspective view of the package of

FIG. 4

with the open end further folded.





FIG. 6

shows a perspective view of the package of

FIG. 5

with the leader folded back onto the pouch.





FIG. 7

shows a perspective view of a closure member in accordance with the present invention.





FIG. 8

shows a side view of the closure member of FIG.


7


.





FIG. 9

shows a perspective view of a light-tight package in accordance with the present invention.





FIG. 10

shows a side view of the package of FIG.


9


.





FIG. 11

shows a side view of the package of the present invention wherein the closure member is disposed at another position on the closure flap.





FIG. 12

shows a perspective view of the package of

FIG. 9

having two closure members.





FIG. 13

shows a perspective view of the package of

FIG. 12

with the closure members ruptured.





FIG. 14

shows a perspective view of the package of

FIG. 12

with the closure members ruptured and the leader extended.





FIGS. 15



a


-


15




i


show perspective views illustrating the use of the package of

FIG. 12

in a cassette.





FIG. 15



j


shows a top view of a closure member.





FIG. 16

shows a perspective view of a package in accordance with the present invention with a closure member folded back on itself.





FIG. 17

shows a perspective view of a package in accordance with the present invention having a closure member comprising a plurality of perforation areas.





FIGS. 18



a


-


18




b


show a perspective view of a package in accordance with the present invention wherein the leader and closure flap are folded on opposite sides of the pouch.





FIGS. 19



a


-


19




c


show perspective views of a package in accordance with the present invention illustrating an alternate fold for the open end of the pouch.





FIG. 20

shows the package of

FIG. 9

introduced into a box.





FIG. 21

shows a perspective view of a second embodiment of a package in accordance with the present invention wherein an adhesive is applied along the entire length of the closure member.











DETAILED DESCRIPTION OF THE INVENTION




The following is a detailed description of the preferred embodiments of the invention, reference being made to the drawings in which the same reference numerals identify the same elements of structure in each of the several figures.




Referring now to

FIG. 1

, a package


10


in accordance with the present invention comprises a pouch


12


and a leader


14


. Pouch


12


can be formed from one sheet, or alternatively, from two generally rectangular sheets


16


,


18


of packaging material. Various materials are suitable for use in making pouch


12


and leader


14


. Sheets


16


,


18


and leader


14


are comprised of a non-rigid, flexible material. If the film sheets disposed within package


10


are photosensitive, sheets


16


,


18


is comprised of an opaque and moisture barrier material so as to not adversely affect the photosensitive characteristics of the film sheets. For example, sheets


16


,


18


can be made of black modified high density polyethylene, a linear low density polyethylene, or a polypropylene. Sheets


16


,


18


are located one above the other in generally parallel planes. They are secured together along three side edges thereof to form an interior space. The fourth side is open to form an opening


20


, through which a stack


22


of film sheets is loaded into the interior space of pouch


12


. Sheets


16


,


18


may be joined by heat sealing or other joining means known to those skilled in the art. Sheets


16


,


18


define a top and bottom face, respectively, of pouch


12


.




As is known in to those skilled in the art, an additional layer(s) may optionally be provided to one or both sides of stack


22


of film sheets prior to being disposed within pouch


12


. The additional layer(s) may be employed to strengthen the stack, protect the stack, and/or facilitate handling of the stack both before and after introduction into a magazine/cassette. As illustrated in

FIG. 1

, an additional layer is shown as a paperboard folder


24


.




Leader


14


is disposed along a side edge of pouch


12


opposite opening


20


. Leader


14


may be integral to pouch


12


, or may joined to the side edge by heat sealing or other joining means known to those skilled in the art. As with sheets


16


,


18


, leader


14


may be made of polyethylene or polypropylene, however, leader


14


need not be of an opaque material as it is not directly shielding the film sheets.





FIG. 2

shows package


10


having stack


22


of film sheets disposed within the interior of pouch


12


, with opening


20


in an open arrangement. Opening


20


is now folded to close opening


20


and secure stacks


22


within pouch


12


, thereby forming a light-tight enclosure of pouch


12


.

FIGS. 3-5

show one method for closing opening


20


. Side ends


30


,


32


of opening


20


of pouch


12


are folded over 90 degrees so that a configuration as shown in

FIG. 3

is obtained. As best shown in

FIG. 4

, edge


34


of opening


20


is then folded over 180 degrees to cover a portion of (or all of) side ends


30


,


32


to form a folded-over portion. The folded-over portion is then folded over 180 degrees onto sheet


16


as best illustrated in

FIG. 5

, forming a closure flap


38


having a front edge


36


adjacent one side of pouch


12


, which is shown as sheet


16


in FIG.


5


.




Leader


14


is folded back onto pouch


12


, shown as being folded back onto sheet


16


in FIG.


6


. As shown, a front edge


40


of leader


14


is directed toward front edge


36


of closure flap


38


. In

FIG. 6

, pouch


12


, leader


14


, and closure flap


38


are sized such that front edge


40


is spaced from front edge


36


. However, leader


14


might overlap closure flap depending on the size of pouch


12


.




A closure member


50


is applied to leader


14


and closure flap


38


to close/secure leader


14


and closure flap


38


in position. As shown in

FIGS. 7-8

, closure member


50


is shown as a strip having a first end


52


, a second end


54


, a top side


56


, a bottom side


58


, and rupturable means such as rupturable portion


64


. Closure member


50


is preferably a flexible member able to be put into tension and resist tearing. Suitable materials for closure member


50


include polypropylene, polyolefin, polyester, or paper. In a preferred embodiment, closure member


50


is comprised of a white biaxially oriented polypropylene.




Disposed on bottom side


58


adjacent first end


52


is a first attachment area


60


. Disposed on bottom side


58


adjacent second end


54


is a second attachment area


62


. First attachment area


60


is spaced from second attachment area


62


such that a non-attachment area


61


is disposed on bottom side


58


intermediate first and second attachment areas


60


,


62


. In a preferred embodiment, first and second attachment areas


60


,


62


comprise an adhesive.




Referring now to

FIGS. 9-11

, package


10


is formed by placing closure member


50


in slight tension and affixing/adhering first attachment area


60


to leader


14


, and affixing/adhering second attachment area


62


to closure flap


38


. As such, closure member


50


secures closure flap


38


and leader


14


in position. Since first attachment area


60


is spaced from second attachment area


62


(with non-attachment area


61


disposed intermediate first and second attachment areas


60


,


62


), closure member


50


is not affixed to pouch


12


, which is illustrated in

FIG. 10

as sheet


16


. Rather, closure member


50


is configured as a “strap”.




Closure member


50


can be affixed to leader


14


at any location; it need not be affixed adjacent front edge


40


. Similarly, closure member


50


can be affixed to closure flap


38


at any location; it need not be affixed adjacent front edge


36


. For example, as illustrated in

FIG. 11

, attachment area


62


is applied to closure flap


38


at a location away from front edge


36


.




The adhesive of first attachment area


60


must be suitable to aggressively adhere to leader


14


to secure leader


14


to closure member


50


, while the adhesive of second attachment area


62


must be suitable to aggressively adhere to closure flap


38


to secure closure flap


38


to closure member


50


. Those skilled in the art will be familiar with suitable adhesives, for example, an acrylic based pressure sensitive adhesive, a water activated adhesive, a solvent adhesive, or heat activated adhesive. A peel-away liner may be employed to shield the adhesive until use; upon use, the liner would be peeled away to expose the adhesive.




First and second attachment areas might be affixed to closure member


50


through means other than adhesive, for example heating sealing or other non-destructive sealing/affixing means known to those skilled in the art.




Closure member


50


further comprises rupturable means such as rupturable portion


64


disposed at first end


52


adjacent first attachment area


60


. Rupturable portion


64


is not disposed within first attachment area


60


. Rupturable portion


64


may be for example perforations (as shown in FIG.


7


), a plurality of minute holes, and/or a combination thereof, as is well known to those skilled in the art. Rupturable portion


64


might also be a notch/tear in an edge of closure member


50


.




In a preferred embodiment, two closure members


50


are employed with package


10


as illustrated in

FIG. 12

, with each applied toward the outside edges of pouch


12


to ensure fold integrity.




Referring now to

FIGS. 12-14

, to open package


10


, a user grasps closure member


50


and ruptures rupturable portion


64


. The puncturing/rupturing/tearing of rupturable portion


64


causes first end


52


to separate from closure member


50


. That is, first end


52


remains adhered to leader


14


at first attachment area


60


while the remaining portion of closure member


50


remains adhered to closure flap


38


by means of second attachment area


62


. Leader


14


is now free to be folded away from pouch


12


while closure flap


38


may be unfolded to access stack


22


of film sheets.




In a preferred embodiment, the magazine or cassette provides ready access to closure member


50


. A preferred cassette is shown in

FIGS. 15



a


-


15




i


wherein a cassette


70


is adapted to move between a closed position and an open position to receive package


10


therein. In the open position, a user positions package


10


within cassette


70


. The user then ruptures rupturable portion


64


of both closure members


50


(

FIG. 15



d


). As shown in

FIG. 15



e


, leader


14


can then be folded away from pouch


12


. The cassette is closed with leader


14


extending outside of cassette


70


(

FIG. 15



f


). Cassette


70


is inserted into a receiving member, such as x-ray equipment, as is shown in

FIG. 15



g


, wherein the user pulls leader


14


to separate pouch


12


from stack


22


. That is, pouch


12


is removed from the cassette, and stack


22


remains within the cassette.




Closure member


50


may comprise one or a plurality of alphanumeric or iconic characters, images, and/or illustrations. For example, as shown in

FIGS. 15



c


-


15




e


and


15




j


, an arrow


71


or image


72


may be disposed on closure member


50


to assist in directing the user in inserting package


10


in the cassette.




If closure member


50


is of a length greater than a width W of package


10


, second attachment area


62


of closure member


50


can be applied at the underside of package


10


(i.e., at any location on sheet


18


), which for the purposes of this invention is still considered to be closure flap


38


. Alternatively, closure member


50


can be folded-back onto itself at closure flap


38


, as shown in

FIG. 16

, using additional adhesive for the folded-back portion.




Closure member


50


may also comprise a plurality of rupturable portion


64


within non-attachment area


61


. Such a plurality may be desired if one closure member


50


is being employed for packages of varying widths. With such a plurality, a user may rupture any one of the rupturable portions to release leader


14


and closure flap


38


.




If pouch


12


is of a small size, leader


14


and closure flap


38


could be folded onto opposite sides of pouch


12


so as to not overlap on each other. For example, as shown in

FIG. 18



a


-


18




b


, closure member


50


is attached to leader


14


and closure flap


38


, however, closure flap


38


is folded to overlap sheet


16


while leader


14


is folded to overlap with sheet


18


.




Those skilled in the art will recognize that package


10


of the present invention can be employed with magazines and cassettes having a different configuration than shown in

FIGS. 15



a


-


15




i


, such as those disclosed in U.S. Pat. Nos. 4,909,389 and 4,933,696.




Those skilled in the art will also recognize that other methods for closing opening


20


may be employed. For example, closure flap


38


may be generated as shown in

FIGS. 19



a


-


19




c


. Side ends


30


,


32


are folded inside to create a trapezoidal shape, which is then folded twice to generate closure flap


38


.




Rupturable portion


64


may be disposed adjacent second end


54


adjacent second attachment area


62


; rupturable portion


64


would not be disposed within second attachment area


62


. Though, if disposed at second end


54


, rupturable portion


64


may be difficult to access for rupturing when pouch


10


is placed within a magazine/cassette having a joint, such as cassette


70


illustrated in

FIGS. 15



a


-


15




i


, since closure flap


38


would abut the joint of the cassette.




For ease of transport and delivery, package


10


might be introduced into a box, such as a telescoping box


74


illustrated in FIG.


19


. Such a box


74


might comprise a bottom part


76


including a shoulder section


78


fixedly connected therewith, and a top part


80


acting as a lid for box


74


which telescopes over shoulder section


78


.





FIG. 21

shows a second embodiment of a package in accordance with the present invention. As illustrated, package


100


comprises at least one closure member


102


having a bottom side, with the bottom side of closure member


102


including an adhesive applied thereto along its entire length. Closure member


102


further comprises a plurality of rupturable portions


64


. When closure member


102


is applied to package


100


, closure member


102


adheres to leader


14


, pouch


12


, and closure flap


38


. Package


100


is positioned within cassette


70


when cassette


70


is in the open position. The user ruptures one rupturable portion


64


of each closure member


50


adjacent leading edge


14


. Cassette


70


is closed with leader


14


extending outside of cassette


70


. Then, once cassette


70


is inserted into the receiving device, the user pulls leader


14


whereupon another rupturable portion


64


ruptures to free closure flap


38


. Applicant has found that, for this embodiment, a rupturable portion adjacent front edge


36


generally ruptures when leader


14


is pulled.




The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.




Parts List






10


package






12


pouch






14


leader






16


,


18


sheets






20


opening






22


stack






24


folder






30


,


32


side ends






34


edge






36


front edge






38


closure flap






40


front edge






50


closure member






52


first end






54


second end






56


top side






58


bottom side






60


first attachment area






61


non-attachment area






62


second attachment area






64


rupturing means






70


cassette






71


arrow






72


image






74


box






76


bottom part






78


shoulder section






80


top part






100


package; second embodiment






102


closure member



Claims
  • 1. A package for enclosing a plurality of sheets, the package comprising:a pouch adapted to receive the plurality of sheets, the pouch comprising a leading end and open along a trailing end opposite the leading end to receive the plurality of sheets, the trailing end being folded back at least once to form a closure flap to light-tightly close the pouch; a leader disposed at the leading end of the pouch and folded back onto the pouch; and a closure member having a first end affixed to the leader, a second end affixed to the closure flap, and a rupturable portion disposed adjacent the first end.
  • 2. The package of claim 1, whereby when the rupturable portion is ruptured, the first end separates from the closure member and adheres to the leader and the remaining portion of the closure member adheres to the closure flap by the second end.
  • 3. The package of claim 1, wherein the first end of the closure member includes a first attachment area, the second end the closure member includes a second attachment area, and a non-attachment area is disposed intermediate the first and second attachment areas.
  • 4. The package of claim 3, wherein the first and second attachment areas comprise an adhesive.
  • 5. The package of claim 4, wherein the adhesive is a pressure sensitive adhesive.
  • 6. The package of claim 1, wherein a front edge of the leader is spaced from a front edge of the closure flap.
  • 7. The package of claim 1, wherein the pouch comprises a top face and a bottom face, and the closure flap and leader overlap the top face.
  • 8. The package of claim 1, wherein the pouch comprises a top face and a bottom face, and the closure flap overlaps the top face and the leader overlaps the bottom face.
  • 9. The package of claim 1, wherein the closure member is a single unitary member comprised of polypropylene.
  • 10. The package of claim 1, wherein the rupturable portion comprises perforations.
  • 11. The package of claim 1, wherein the closure member includes an alphanumeric or iconic character, image, or illustration.
  • 12. The package of claim 1, wherein the closure member comprises a plurality of rupturable portions.
  • 13. The package of claim 1, wherein the second end of the closure member is folded back onto itself when affixed to the closure flap.
  • 14. A package for enclosing a plurality of sheets, the package comprising:a pouch adapted to receive the plurality of sheets, the pouch comprising a leading end and a trailing end opposite the leading end, the pouch being open along the trailing end to receive the plurality of sheets, the trailing end being folded back at least once to form a closure flap to light-tightly close the pouch; a leader disposed at the leading end of the pouch and folded back onto the pouch; and at least one closure member having a first end, a second end, a top side, and a bottom side, a first attachment area disposed at the first end on the bottom side, a second attachment area disposed at the second end on the bottom side, a non-attachment area disposed on the bottom side intermediate the first and second attachment areas, an adhesive disposed on the first and second attachment areas, and a rupturable portion disposed at the first end adjacent the first attachment area, the first attachment area being adhered to the leader, the second attachment area being adhered to the closure flap, such that when the rupturable portion is ruptured, the first end separates from the closure member and adheres to the leader at the first attachment area and the remaining portion of the closure member adheres to the closure flap at the second attachment area.
  • 15. The package of claim 14, wherein the pouch comprises a top face and a bottom face, and the closure flap and leader overlap the top face of the pouch.
  • 16. The package of claim 14, wherein the pouch comprises a top face and a bottom face, and the closure flap overlaps the top face of the pouch and the leader overlaps the bottom face of the pouch.
  • 17. The package of claim 14, wherein the closure member is a single unitary member comprised of polypropylene.
  • 18. The package of claim 14, wherein the rupturable portion comprises perforations.
  • 19. The package of claim 14, wherein the closure member includes an alphanumeric or iconic character, image, or illustration.
  • 20. The package of claim 14, wherein the adhesive is a pressure sensitive adhesive.
  • 21. The package of claim 14, wherein the closure member comprises a plurality of rupturable portions.
  • 22. The package of claim 14, wherein the second end of the closure member is folded back onto itself when affixed to the closure flap.
  • 23. A package for enclosing a plurality of sheets, the package comprising:a pouch adapted to receive the plurality of sheets, the pouch comprising a top face, a bottom face, a leading end, and a trailing end opposite the leading end, the pouch being open along the trailing end to receive the plurality of sheets, the trailing end being folded back at least once to form a closure flap to light-tightly close the pouch; a leader disposed at the leading end of the pouch and folded back onto the pouch; and at least one closure member having a first end, a second end, a top side, a bottom side, an adhesive disposed on the bottom side, and a plurality of rupturable portions disposed between the first end and the second end, the bottom side of the closure member being adhesively affixed to the leader, the top face, and the closure flap.
  • 24. The package of claim 23, wherein the closure flap and leader are folded back to overlap the top face of the pouch.
  • 25. The package of claim 23, wherein the closure flap is folded back to overlap the top face of the pouch and the leader is folded back to overlap the bottom face of the pouch.
  • 26. The package of claim 23, wherein the second end of the closure member is folded back onto itself when affixed to the closure flap.
  • 27. A package for enclosing a plurality of sheets, the package comprising:a pouch adapted to receive the plurality of sheets, the pouch comprising a leading end and open along a trailing end opposite the leading end to receive the plurality of sheets, the trailing end being folded back at least once to form a closure flap to light-tightly close the pouch; a leader disposed at the leading end of the pouch and folded back onto the pouch, the leader being spaced from the closure flap; and a closure member having a first end affixed to the leader, a second end affixed to the closure flap, and a rupturable portion which is rupturable to separate the closure member into first and second segments with the first segment adhering to the leader at the first end and the second segment adhering to the closure flap at the second end.
  • 28. The package of claim 27, wherein the rupturable portion is disposed adjacent the first end.
  • 29. The package of claim 27, wherein the rupturable portion is disposed adjacent the second end.
US Referenced Citations (7)
Number Name Date Kind
3741386 Schmidt Jun 1973 A
4909389 Plessers et al. Mar 1990 A
4933696 Schmidt et al. Jun 1990 A
5008694 Tajima et al. Apr 1991 A
5251755 Kausch Oct 1993 A
5649411 Dirx Jul 1997 A
20020004179 Nishiyama Jan 2002 A1
Foreign Referenced Citations (2)
Number Date Country
0 250 851 May 1987 EP
0 313 686 Oct 1987 EP
Non-Patent Literature Citations (1)
Entry
PCT International Application, No. WO 99/37541, Publication Date: Jul. 29, 1999, Title: Bag Closing Method and Apparatus.