US 3442402 A
Description (OCR text may contain errors)
y 1969 R. o. BAXTER 3,442,402
DUNNAGE SERVICE Original Filed Sept. 22, 1964 COMPRESSED AIR PAPER PLASTIC FIG. 5
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24 I3 25 BY ROBERT OQBAXTER ATTORNEY United States Patent DUNNAGE SERVICE Robert 0. Baxter, Camden, Ark., assignor to International Paper Company, New York, N.Y., a corporation of New York Continuation of application Ser. No. 398,214, Sept. 22,
1964. This application Nov. 10, 1966, Ser. No. 593,589 Int. Cl. B65g 1/14; B61d 45/00 US. Cl. 21410.5 4 Claims ABSTRACT OF THE DISCLOSURE An air-inflated dunnage unit made from paper and plastic and closed at its ends by a clamp formed from a split hollow tube or the like and a rod wider than the split in the tube.
This application is a continuation of application Ser. No. 398,214 filed Sept. 22, 1964, now abandoned.
This invention relates to a removable closure for tube, or bag, ends. More particularly, it relates to a reusable clamping device for tightly shutting the flattened ends of multi-wall tubes, or bags, made from sheet materials such as paper or plastic or combinations thereof and otherwise adapted to be used as inflated disposable dunnage.
The manufacture of multi-wall tubes from paper or the like is broadly old, though improvements keep coming along. See, for example, co-pending U.S. Ser. No. 158,829, filed Dec. 12, 1961 now Patent No. 3,266,710. And, in the production of bags from such tubes is is generally old to close one or both ends of the tubes by folding, crimping, sewing, gluing, pasting, heat-sealing or combinations, though other improvements keep coming along. Of. US. Pat. No. 3,129,646, issued Apr. 21, 1964 to Hollis. It is even old to clamp tubes or bags of paper shut, though not, it appears, multi-Wall bags meant to hold a 100 lb. load of concrete, fertilizer, or the like. See expired U.S. Pat. No. 288,118, issued Nov. 6, 1883 to Reidy.
The use of paper and plastics in place of rubber or the like in the manufacture of inflatable dunnage is also known. See US. Pat. No. 3,028,981, issued Apr. 10, 1962 to Ford et a1. So is the use of multi-wall bags made from paper and plastic. See US. Pat. No. 3,072,270, issued J an. 8, 1963 to Tolby et a1. Such use has much to commend it. A single inflatable rubber dunnage bag adapted for use in railroad box cars costs of the order of $80.00, and neither the shippers carrier nor customer will ordinarily assume the responsibility for its return, while the paper and plastic counterparts can be made cheaply enough to justify their use only once (and with no thought of return). But the commercial exploitation of disposable dunnage made from inflated multi-wall bags has lagged, because no really suitable means of closing the bags, or the tubes from which they stern, has been available heretofore. Mere sewing, gluing, or the like has not proven adquate in the maintenance of an elevated air pressure in such a bag, or of the integrity of the bag in its exceedingly trying role as dunnage wherein it is meant to prevent or mitigate damage arising from the shifting of heavy loads aboard moving railroad cars, ships, trucks, or aircraft by absorbing the tremendous impacts and pressures between elements of such loads.
Now, however, means have been discovered which cure the above-recited inadequacies of the past simply and economically, and which make inflatable disposable dunnage made substantially from paper commercially feasible. These means include a device for, and a method of, closing at least one end of a tube or the other end of a bag already formed from such a tube and the closure which results from the use of the device and method. The device comprises, boardly, a hollow member having means defining a longitudinal split of predetermined width therein and a rod member having a width greater than the width of the split in the hollow member and being adapted to be disposed within the hollow member when a flattened tube, or bag, end is wrapped about the rod member. Rod members can have widths less than the splits in the hollow members if the thicknesses of the tube ends wrapped about the rod member makes the resulting units wider than the splits. The method entails flattening the tube, or bag, end and inserting it in the hollow member when it is wrapped about the rod member. Clearly, the sequence of the steps is not critical. And the closure is formed when the flattened tube, or bag, end is wrapped about the rod member and disposed within the hollow member with a portion of such tube, or bag, end extending through the split in the hollow member.
For a better understanding of the present invention, reference should be had to the attached sheet of drawings wherein FIGURE 1 shows an isometric view of two identical embodiments of the clamping device of the present invention, one wholly included in a closure for a tube end and the other partly included;
FIGURE 2 shows an isometric view of a portion of a second embodiment of a clamping device in accordance with the present invention which is wholly included in a closure for a tube end;
FIGURE 3 shows an isometric view of a portion of a third embodiment of a clamping device in accordance with the present invention which is partly involved in a tube end closure made in accordance with the present invention;
FIGURE 4 shows an end view of an inflated tube equipped at both ends with the clamping devices of the present invention and disposed as dunnage between two large rolls of kraft paper as they ride in a railroad car; and
FIGURE 5 shows a sectional view of a portion of the paper tube of FIGURE 4 having a plastic bladder therein.
In FIGURE 1, we see a multi-wall paper tube 10 made in accordance with, for instance, co-pending U.S. Ser. No. 158,829, filed Dec. 12, 1961 now Patent No. 3,266,710. Projecting through a hole in tube 10 is a valve stem 11 which is connected to an inflatable bladder (not shown) made of high density polyethylene, rubber, or the like, and disposed within the tube. The valve is of the type used in automobile tire tubes. The tube is made up of, for example, six or seven plies of lb. kraft paper. And the bladder can be heat-sealed at its ends to the inside of the inner ply of the paper tube at its end, or not, at the option of the manufacturer.
Also in FIGURE 1, we see the flattened upper end of tube 10 folded or rolled upon itself so as to fit within hollow member 12 which is identical to hollow member 13 on the other, lower end of tube 10 in that they are both, for example, pieces of 1" water pipe having a longitudinal slot, or split 12a, mesuring /2" across or in width. And a flat rod member 14 is shown poised for insertion first in the fold of the upper end of tube 10 and second in the hollowed-out portion of member 12, together with such folded end. The rod can be of metal, wood, etc. but requiges a width or diameter of greater than /2" when the slot 12a has such dimension.
FIGURES 2 and 3 merely emphasize the point that the shapes of the cross-sections of the ovoid or horseshoe hollow members 15 and 16 and triangular or round rod members 17 and 18 of the clamping devices of this invention are not of the essence thereof and that such devices can be made from various materials, e.g., iron, steel, aluminum, wood, plastics, previously formed into various shapes and still provide closures for tubes 19 and 20.
FIGURE 4, on the other hand, shows the unit of FIG- URE l at work. Both ends of the tube are clamped shut and closed in accordance with the invention. The tube is then disposed between two large rolls of kraft paper 21 and 22 located in a box car 23 and kept from rolling longitudinally of the car by chocks 24 and 25. Next, the tube which measures approximately 30" x 34" is inflated with air to a pressure of from about 4 to 15 p.s.i. and to fill the approximately 12 space between rolls 21 and 22 which weigh on the order of a ton each. (Such a tube when unrestrained can withstand from about 18 to 27 p.s.i. pressure before rupture.) At this juncture, the tube is capable of preventing or mitigating damaging lateral shifts of the rolls when the railroad car sways as it moves.
As evidence of the effectiveness of the present invention, tests were conducted wherein a railroad car was loaded with two tiers of kraft paper rolls like rolls 21 and 22 and was humped at various speeds against a line of four flat cars which had their brakes set and were loaded with pulp wood destined for a paper will. Multiwall tubes (measuring approximately 30" x 64) made of five to seven plies of 100 lb. kraft paper and equipped with the devices of the present invention were placed between the tiers of rolls and laterally to the cars length and inflated with air as noted above. The tubes withstood repeated shocks even when the humped car achieved 1 1 mph. before impact with the line of flat cars and in no case was the clamping device of the present invention the point of failure.
What is claimed is:
1. A dunnage unit comprising an air inflated tube having a outer plurality of plies of paper, an inner ply of plastic substantially co-exten'sive with the tube and forming a bladder means within the tube, valve means extending from the bladder means through the tube, said tube and bladder means being flattened on at least one end, said end being foldable to provide a fold in both the tube and bladder means and a closure means comprising a hollow member having means defining a longitudinal split of predetermined width therein and a rod member having a width greater than the width of the split and adapted to be disposed within the hollow member with the said flattened end of both the tube and the bladder means being folded about the rod member.
2. The dunnage unit of claim 1 wherein the tube is inflated with air to a pressure of from about 4 to 15 p.s.i.
3. A method of forming a dunnage unit having an outer plurality of plies of paper forming a tube and an inner ply of plastic which forms a bladder within and substantially coextensive with the tube, connecting a valve means to the bladder and passing .it through the tube walls to the outside thereof, flattening at least one end of the tube and the end of the bladder therein, folding he said flattened ends of the tube and bladder to simultaneously form a fold in the tube and the bladder, inserting the fold in a hollow member having means defining a longitudinal split of predetermined width there-in, inserting a rod member having a width greater than the width of the split into the fold to closethat end of the unit and inflating the tube by passing air through he valve means.
4. The method of claim 3 wherein the tube is inflated with air to a pressure of from about 4 to 1'5 p.s.i.
References Cited UNITED STATES PATENTS 2,319,316 5/ 1943 Gerendas a 229- 2,601,568 6/1952 Sussenbach et al. 22965 3,072,270 1/1963 Tolby et al 2l4-10.5 3,199,689 8/1965 Feldkamp 214- FOREIGN PATENTS 970,970 2/1959 France.
335,602 2/ 1959 Switzerland.
882,596 11/1961 Great Britain.
GERALD M. FORLE'NZA, Primary Examiner.
F. E. WERNER, Assistant Examiner.
US. Cl. X.R. 105-3 69