Abstract:
The valve bag includes a bag body having a valve end portion, the valve end portion constructed to form a filling passage in which a valve sleeve is inserted. The valve sleeve has a first end extending into the interior of the valve bag and a second end extending exteriorily from the bag body. A valve protection member is secured to the second end.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to sealable valve bags and, more specifically to the valve sleeve used to fill and seal the valve bags. These shipping sacks are commonly used to contain and transport granular products, examples of which are fertilizers, animal feeds or grain. 
     BACKGROUND OF THE INVENTION 
     Flexible bags such as paper shipping sacks may include a sealable valve sleeve placed in a filling valve, the filling valve is located in a comer of the flexible bag to allow introduction of material that is to be held within the bag. These shipping sacks are commonly used to contain and transport material such as granular products, examples of which are fertilizers, animal feeds or grain. The sealable sleeve provides a convenient means to fill and securely close the flexible bag to prevent the contents of the bag from leaking or sifting out of the bag once the bag has been filled. Sleeves may be constructed of a variety of materials such as paper, polyethylene tubing or a thermoplastic liner. 
     A typical sleeve for a paper shipping sack, such as a pasted valve type multiwall shipping sack, is made from a rectangular sheet of kraft paper that is rolled into a cylindrical shape and secured in the cylindrical shape by overlapping or abutting the opposing edges of the sheet of paper to one another and gluing to form a seam. Such a sleeve is described in commonly assigned U.S. Pat. No. 6,164,823, the disclosure of which is hereby expressly incorporated by reference. In order to seal the valve sleeve and therefore the valve passage after the shipping sack is full, heat, typically generated by ultrasonic vibrations, is applied to the exterior surface of the valve sleeve melting the thermoplastic film liner sealing the sleeve and securing the contents within the shipping sack. 
     However, due to the interaction between the vibrating jaw of the ultrasonic generator and the outer surface of the valve sleeve, the valve sleeve is often damaged. The damage to the valve sleeve may make it possible for the contents of the bag to leak or sift out of the bag even after the sealing operation has been completed. 
     Valve sleeves have been constructed of multiple sheets of paper to strengthen the valve sleeve and facilitate filling of the flexible bag. This design has a high non-conforming rate, often as great as fifteen percent, because the difficulties of aligning the several sheets of paper to the valve sleeve results in discontinuities around the valve sleeve and allow product to escape from the bag. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the valve bag, having a valve sleeve constructed in accordance with the invention, with the valve sleeve in the closed position; 
     FIG. 2 is a perspective view of the valve bag of FIG. 1, with the valve sleeve in the open position; 
     FIG. 3 is a cross-sectional view of the valve sleeve of FIG. 1, taken along line  1 — 1  of FIG. 1; 
     FIG. 4 is a cross-sectional view of the valve sleeve of FIG. 2, taken along the line  2 — 2  of FIG.  2  and showing the ultrasonic generator in contact with the protection member; 
     FIG. 5 is a view similar to FIG. 2, showing text or graphics on the protective member; and 
     FIG. 6 is a view similar to FIG. 4, showing the protective member extending into the valve passage. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A valve sleeve for a flexible bag constructed in accordance with the present invention includes a cylindrical tube including a heat sealable liner and protective member secured to the cylindrical tube. The protective member is arranged to cover a portion of one end of the valve sleeve extending from the valve passage protecting the valve during the sealing process. 
     A flexible bag having a valve sleeve constructed to include a valve sleeve in accordance with the invention will be resistant to the damage caused during sealing of the valve sleeve and prevent contents of the flexible bag from escaping due to the damage. 
     Further, a flexible bag having a valve sleeve constructed to include a protective member in accordance with the invention will be easier to manufacture and result in less scrap and non-conforming valve bags. The protective member of the present invention is external to the valve passage to prevent the possibility of discontinuities, and is smaller than the valve sleeve itself to facilitate alignment, both of these improvements make the flexible bag easier to manufacture and decrease the non-conforming rate. 
     Additional benefits and features of the invention will be apparent to those skilled in the art from a review of the following detailed description taken in conjunction with the drawings and applied claims. 
     The following description of the disclosed embodiment is not intended to limit the scope of the invention to the precise form or forms detailed herein. Instead, the following description is intended to be illustrative of the principles of the invention so that others may follow its teachings. 
     Referring now to the drawings, a valve bag capable of being sealed is shown in FIGS. 1-4. A valve bag  10  includes side walls  12 ,  14 , in-folded flap  16 , and outer flaps  18 ,  20 . The valve bag  10  is preferably a valve bag having multiple walls A, B, C adhered together, at least in portion, by layers of adhesive D. 
     The valve bag  10 , in order to facilitate filling and subsequent sealing also includes a valve sleeve  22 . The valve sleeve  22  is cylindrical tube that has a uniform length from its outside end  26 , to its inside end  28 . The valve sleeve  22  may be formed from a single, rectangular sheet of relatively stiff kraft paper having a thermoplastic film  24  that coats the entire interior of the valve sleeve  22 , and such as disclosed and described in the aforementioned U.S. Pat. No. 6,164,823. A valve sleeve protection member  34  is affixed to the exterior of the valve sleeve  22 , substantially adjacent to the outside end  26 , and extending towards its inside end  28 , substantially adjacent with side wall  12 . The entire valve sleeve assembly  36 , valve sleeve  22  and protection member  34  is affixed in the filling passage  38  created between the in-folded flap  16  and outer flaps  18 ,  20  and secured by adhesive D. 
     The filling of the valve bag  10 , is accomplished by inserting a fill nozzle (not shown) into the valve sleeve passage  30  defined by the valve sleeve  22  and discharging material into the interior  32  of valve bag  10 . Upon completion of filling, the valve sleeve  22  is typically sealed by positioning the outside end  26  between a head  40  and an anvil  42  of an ultrasonic generator. The protection member  34  is thus positioned between the head  40  and the valve sleeve  22 . Ultrasonic energy generated by the vibration of the head  40  activates the thermoplastic film  24  to seal the valve sleeve  22 . The protection member  34  protects the kraft paper surface of the valve sleeve  22  from damage created by the motion of the head  40 . Accordingly, a tight seal is achieved and damage, such as holes or imperfections, that would allow filling material to escape the valve bag  10  after sealing was complete is reduced. 
     In another embodiment shown in FIG. 5, the valve bag  10  includes a valve sleeve protection member  34  attached to a surface  44  of the valve sleeve  22 . The valve sleeve protection member  34  has been adapted to display text or graphics  46 . 
     In another embodiment shown in FIG. 6, the protective member  34  is shown to extend into the valve bag filling passage  38 . The protective member  34  is attached to the lower surface  48  with adhesive D. The protective member  34  extends inward towards the interior  32  of the valve bag  10  but is not attached to any of the multiple walls A, B, or C. 
     Those skilled in the art will appreciate that, although the teachings of the invention have been illustrated in connection with a certain embodiment, there is no intent to limit the invention to said embodiment. On the contrary, the intention of this application is to cover all modifications and embodiments fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.