Flexible bags – With closure – Including auxiliary means for forming leakproof closure seal
Reexamination Certificate
2000-02-25
2001-07-31
Shoap, Allan N. (Department: 3727)
Flexible bags
With closure
Including auxiliary means for forming leakproof closure seal
C224S148200, C383S035000, C383S061100, C383S906000, C383S083000, C383S089000
Reexamination Certificate
active
06267506
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an improved closure for bags and like flexible containers which seals the bag fluid-tight and gas-tight yet allows easy and rapid reopening of the bag for access to its contents, and to a method directed to such an improved closure. The invention also relates to a fluid-tight and gas-tight bag having an improved leak-proof closure which allows easy and rapid reopening of the bag.
2. Prior Art
It is frequently desirable to have a light, resealable bag that is fluid-tight or gas-tight, either to keep the contents of the bag dry or to prevent liquids or gases from leaking out of the bag. The requirements in a bag for a leak-proof closure, yet one providing easy access to the bag and overall light weight, have a higher premium in more rigorous applications, e.g., cycling or back country hiking. Traditional methods of closure include so-called zip-lock or pressure strips, clamps, clips, and threaded caps. Zip-lock strips have limited durability and often do not form a true gas-tight seal. Expensive molding equipment or tooling may be needed to form these closures. Such a closure may add an awkward element to the bag and access to the contents of the bag may be restricted if the nature of the closure, such as a cap, is narrower or more rigid than the main body of the bag.
Light weight, resealable bags are used increasingly in sporting activities. Limited access to the interior of prior art bags makes cleaning more difficult creating the potential for unsanitary or at least offensive conditions. Once liquid products placed in such sporting bags are consumed, the remaining deposits if not immediately and thoroughly cleaned encourage the growth of bacteria and mold. If left uncleaned, such growths can leave ugly stains on the bag, may tenaciously retain offensive odors, taint any other fluids subsequently introduced into the bag, and can create serious health risks. Regular and thorough cleaning is therefore critical, especially if it is desired to use dairy-based products in the bag. Prior art bags which are truly fluid- or gas-tight do not provide adequate access to their interiors for cleaning.
Many flexible bags have been developed which can be sealed and resealed to close the bag's contents from environmental contaminants. In particular, several closures have been developed which improve the seal by rolling or folding that portion of the bag near the opening back upon itself For example, Dernmis, U.S. Pat. No. 5,816,709, discloses a leak-proof travel bag for carrying items containing liquids, such as toiletry products, while traveling. The Denius bag shows a zip-lock closure for sealing and resealing the opening of a water-proof bag. The bag is closed by sealing the opening with the zip-lock closure, folding the closure strip over once, then again, whereupon it is sealed to the bag using a hook-and-loop-type fastener, and finally sealing the folded-over portion with a flap using a second hook-and-loop-type fastener.
Rinecker, U.S. Pat. No. 3,446,420 discloses a flexible mouth container wherein the mouth of a container having a sheet-like opening is folded over upon itself and secured with a hook-and-loop-type fastener. Similarly, Vani Loan, U.S. Pat. No. 3,203,551 discloses a filter bag including a cover flap to close the bag. The cover flap is folded over and held in place against the bag with a hook-and-loop-type fastener or a plastic zipper and locking tabs. Finally, Latia, U.S. Pat. No. 2,342,406 discloses a fumigant bag which is closed by joining two stiff, but bendable, strips at the mouth of the bag and folding them down together several times where they are secured in place with ties.
While the roll-down style closures have certain advantages over prior art closures, they tend not to form perfect seals and, especially when the contents of the bag are under pressure, the rolled part of the bag may unroll or loosen thereby decreasing the effectiveness of the seal. There is accordingly a need for an improved bag closure which creates a fluid-tight or gas-tight seal yet which is simple to operate, provides easy and rapid opening for access to the contents of the bag, is light weight, and is inexpensive to manufacture.
SUMMARY OF THE INVENTION
The invention comprises a flexible bag made of two sheets of leak-proof material permanently joined on three sides thus forming an opening at the one remaining side. A semi-rigid splint is fixed to one of the sheets below the opening at a distance of at least twice the width of the splint and there extends from side to side across the entire width of the opening. The splint is flexible, but at rest holds the sheets straight and in parallel alignment. The bag is easily opened by bending the splint and separating the two sheets. A flap of fastening material is joined to the front of the bag at a line approximately twice the width of the splint below the lower edge of the splint. A cooperating panel of fastening material is attached to the back of the bag beginning just below the lower edge of the splint. Closure is performed by first folding an upper section of the two sheets disposed above the upper edge of the splint forward over the splint at a fold line coincident with the upper edge of the splint. A second fold is made by folding the upper section forward over at a fold line coincident with the lower edge of the splint. The second fold turns the first section back upon itself in a tight reverse fold trapped between the splint and the bag material beneath and just below the splint. The splint is then folded forward over again which brings the cooperating panel on the back of the bag adjacent to the fastening flap on the front of the bag. The fastening flap is then fastened to the cooperating panel to hold the folds of the bag material tightly around the splint. In particular, the reverse fold is held snugly in place by the fastening flap. The splint prevents the folded material from unrolling because of the resistance provided by its width.
The seal created by the above closure gets tighter as the pressure of the contents of the bag is increased. The folding pattern of the invention places the folded section between the opening and the splint inside the folds of bag material from below the splint. If pressure from contents of the bag is introduced into the latter folds they will force the two sheets there apart and hence expand against the inner folded section, including the reverse fold, increasingly tightening the inner folds in direct proportion to the expansive pressure from the surrounding folds and thus tightening the seal formed by the inner folds. Accordingly, the closure is particularly effective where the contents of the bag are under pressure, as for example, if a gaseous material were introduced to the bag after it had been closed.
In one embodiment of the invention, the bag is provided with a tube having a valve. After the bag is closed, contents may be introduced into the bag through the tube. For instance, water may be placed in the bag after it is closed and then drawn out as needed through the tube. After all the water is consumed, the bag can be opened for cleaning and reuse. It is desirable to use material for construction of the bag which is not only leak-proof, but appropriately puncture resistant depending upon the ruggedness of the anticipated use.
REFERENCES:
patent: 488783 (1892-12-01), Weber
patent: 1236159 (1917-08-01), Gatlin
patent: 1782240 (1930-11-01), Litchfield
patent: 1919819 (1933-07-01), Williams
patent: 2138066 (1938-11-01), Matchett
patent: 2246596 (1941-06-01), Moore
patent: 2342406 (1944-02-01), Latta
patent: 2345434 (1944-03-01), Sterling
patent: 2688435 (1954-09-01), Vogt
patent: 3203551 (1965-08-01), Van Loan
patent: 3212698 (1965-10-01), Balcom
patent: 3254829 (1966-06-01), Cooper
patent: 3446420 (1969-05-01), Rinecker
patent: 3545668 (1970-12-01), Hultberg
patent: 4356954 (1982-11-01), Mojonnier
patent: 4876125 (1989-10-01), Akao et al.
patent: 4911563 (1990-03-01), Ciani
patent: 5582889 (1996-12-01), Pedri
Beverly Brian
Hylton Robin A.
Shoap Allan N.
LandOfFree
Fold-top closure and method therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fold-top closure and method therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fold-top closure and method therefor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2460618