Bulk Material Container

The present invention pertains to bulk material containers and more particularly, to bulk material containers fabricated from reinforced kraft paper or the like, for transporting and storing bulk materials having means for dispensing bulk material from the bottom thereof.

Paper and paperboard containers are desirably used for transporting and storing materials due to their light weight and low cost as well as their capability of being stored in minimal space in a compact, folded, knocked-down state. For transporting and storing bulk materials, however, the structure of the containers must be sufficiently strong to hold extremely large weights, often on the order of a ton. Due to the large size and weight of the bulk material placed in the container, it has also been found desirable to construct such containers to permit dispensing of the contents from the bottom, thereby obviating the necessity of tipping the containers to remove the contents.

One such bulk material container is known as a sling bin and is manufactured by the St. Regis Paper Company of Nyack, N.Y. A sling bin is a large open mouthed bag adapted to be shipped and stored flat, which can be erected and filled with bulk material while suspended so that the total bin capacity can be utilized. The bin is provided with opposed loops extending upwardly from opposed portions of the bag mouth which are folded back upon themselves and secured to the bag sidewalls to form a pair of slings for suspending the bin from a pair of horizontal supports or the like provided in conjunction with a support frame. Spring clamps attached to the support frame are used to hold the bag or bin mouth open during filling of the bin with bulk material.

After filling, the bin can be transported to a storage or unloading site by the insertion of a pair of fork lifts of a forklift truck through the slings. The bin bottom was equipped with a solid paperboard one-way slide put in place during the bin construction. Access from one side only was possible and no handle was included. Complete removal of the slide valve or gate is necessary to initiate product withdrawal through a circular opening or hole centered in the bottom of the bin. However, no means were available to vary or stop the flow or removal of the product once the slide valve or gate was removed.

In order to rectify this condition and to provide control over the rate of flow or discharge of the bulk material from the bin, the bin bottom is provided with a double wall including a pair of aligned dispensing openings. A slide valve is inserted between the panels of the double wall of the bin bottom and has an off-center opening in the double wall to dispense the bulk contents of the bin. The flow of material from the bin can be controlled by partial in lieu of full registration of the dispensing openings in the bin bottom and slide.

However, if the bin is opened with the slide valve too far to one side or with insufficient extension from both sides of the bin bottom wall, the slide may be inoperable for its intended purpose either because it will be pinched or incapable of being slid axially along the bottom of the bin from one side thereof against the downward force of the great weight and bulk of material housed in the bin, or the slide valve cannot be gripped to be pushed and simultaneously pulled from opposed sides of the bin. Accordingly, the slide valve is provided with handles on both opposite, lateral ends thereof, which are accessible from both sides of the bin when the hole in the slide valve is in registration with the holes in the bin walls.

The handles may be cut openings in the slide valve or the valve may be doubled back upon itself at its opposite ends and fastened and a dowell inserted through the looped back portion to serve as a handle member.

Further objects and advantages will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIG. 1 is a perspective view of the bulk material container of the present invention;

FIG. 2 is a perspective view of a slide valve used with the container of FIG. 1 to dispense bulk material from the container;

FIG. 3 is a cross-sectional view taken substantially along the plane indicated by line 3--3 of FIG. 1;

FIG. 4 is a cross-sectional view taken substantially along the plane indicated by line 4--4 of FIG. 3;

FIG. 5 is a perspective view of the container of FIG. 1 being filled;

FIG. 6 is a perspective view illustrating the manner of transporting and dispensing bulk material from the container of FIG. 1;

FIG. 7 is a partial perspective view of the bottom of the container of FIG. 6, further illustrating the manner in which material is dispensed from the container;

FIG. 8 is a partial perspective view of the bottom of the container of FIG. 1 equipped with an alternate type of slide valve;

FIG. 9 is a partial plan view of the slide valve shown in FIG. 8;

FIG. 10 is a perspective view of a reinforcing girdle for use with the bulk material container of the present invention; and

FIG. 11 is a perspective view of the bulk material container of the present invention having the girdle of FIG. 10 installed thereon.

Referring now to the drawings in detail, wherein like numerals indicate like elements throughout the several views, the bulk container or sling bin 10 of the present invention can include a bag member 11 having a sidewall 12 provided with looped extensions or slings 14, 16 formed by bending each of the ends of auxiliary sidewalls 13, 15, and bottom wall 18 secured to opposed portions of sidewall 12 and bottom wall 17 of bag 11 respectively, in a loop back upon itself and adhesively securing the loops or slings to the adjacent auxiliary sidewall member. Bag 11 can be constructed of kraft paper, polyethylene, aluminum foil/paper laminates, or other materials such as woven fabrics of polypropylene, polyethylene, or other synthetic or natural products. Additionally, a polyethylene liner (not shown) can be inserted into bag 11 for product protection. The auxiliary sidewalls 13, 15 and bottom wall 18 each contain an inner and outer ply of stiff paper material or woven synthetic fabric, the inner plies being designated 13a, 15a and 18a, while the outer plies are designated 13b, 15b and 18b, respectively. Typical materials which can be used for auxiliary sidewalls 13, 15 and bottom wall 18 are fiber reinforced kraft paper and woven polypropylene. The auxiliary sidewall plies 13a, 13b and 15a, 15b are adhesively bonded to each other, except along bottom wall portions 18a, 18 b for a purpose to be described hereinafter.

As shown in FIG. 5, the bin 10 can be supported on a frame 22 by inserting looped extensions or slings 14, 16 on a pair of bars or pipe supports 24, 26, respectively, on frame 22. The bin mouth 25 is opened and spring clamps 28 are all connected between the mouth and frame 22 to hold the mouth 25 open. The combined bottom wall 17, 18 can be supported on a dolly D. The bin 10 can then be filled with bulk material from a tube T and after filling, the bin 10 can be closed and transported to storage or an unloading site by the insertion of a pair of fork lifts 27, 29 of a forklift truck through the slings 14, 16. (FIG. 6).

The bin bottom wall panels 17 and 18a, 18b are provided with registered openings 30, 32, and 41 respectively. Received between unsecured, spaced plies 18a, 18b of auxiliary bin bottom 18 is a slide valve plate 34 having a coating of silicone or polyethylene to reduce sliding friction. In general, slide valve plate 34 can be constructed of any thin material strong enough to hold the bulk material M contained in bag 11 while closed, and to be opened and closed under load. A low coefficient of friction is desired in order to facilitate sliding the valve. Typical materials include heavy duty kraft paper, liner board, synthetic plastic sheets of polyethylene, polypropylene, nylon or polycarbonate, or a laminate or sandwich of any of these materials. The slide valve 34 is provided with openings or handles 36, 38 on both opposite, lateral ends thereof, along with off-center opening 40 extending therethrough, which is adapted to be placed into and out of full or partial registration with openings 30, 32 and 41 in bottom wall 17 and plies 18a, 18b to control the flow rate and dispensing of bulk material M from bin 10, as shown in FIG. 7, from the interior of bin 10, through openings 30, 32, 40 and 41. The handle openings 36, 38, because of the off-set nature of opening 40, are accessible from both sides of the bin 10 when the opening 40 in the slide valve 34 is in partial or full registration with the holes or openings 30, 32, and 41 of the bin walls 17 and 18a, 18b.

As shown in FIGS. 8 and 9 the handles may be formed by doubling back upon itself the slide valve 34 at its opposite ends and fastening the valve to itself by staples or the like as shown at 42. A dowel 44 inserted through the looped back portion of slide valve 34 aids in gripping slide valve 34 through openings 46 cut in each looped end portion of slide valve 34.

Circumferential structural support can be added to bin 10 by providing a girdle 50 around bag 11 and auxiliary sidewalls 13, 15, as shown in FIGS. 10 and 11. Girdle 50 can be constructed of laminated, fiber reinforced kraft paper, or the like and in the form of a sleeve which is installed around the periphery of bag 11 and auxiliary sidewalls 13, 15. Girdle 50 is secured to bag 11 by adhesive means, such as glue spots located at various points on the interior surface of girdle 50. Girdle 50 includes a seam 52 which is adhesively sealed along its length.

It has been found that a girdle is useful when bag 11 and auxiliary sidewalls 13, 15 are constructed of paper materials, to add necessary strength to the overall bin assembly. Such a girdle has been found to be unnecessary when bag 11 and auxiliary sidewalls 13, 15 are fabricated from stronger, woven synthetic fabric materials.