US3414140A - Dunnage - Google Patents

Description

Dec. 3, 1968 J. G, FELDKAMP 3,414,140

DUNNAGE Filed Aug. l, 1966 United States Patent A O 3,414,140 DUNNAGE John G. Feldkamp, Homewood, Ill., assignor to Interlake Steel Corporation, Chicago, Ill., a corporation of New York Filed Aug. 1, 1966, Ser. No. 569,358 11 Claims. (Cl. 214-105) ABSTRACT OF THE DISCLOSURE A pneumatic dunnage device for cushioning a load in a transportation vehicle. The device has a flexible inflatable bladder covered with a reinforcing shroud and the bladder is provided with valve means to permit ination of the device. A reinforcement patch is provided on the bladder wall opposite the position of the valve means for stiifening the bladder in the region of the patch to minimize weakening ofthe bladder in that region due to forces on the bladder caused by inrushing air when the device is inflated through the valve means.

This invention relates to the art of shoring merchandise and particularly to an improved shoring or dunnage device.

Patent No. 3,199,689, issued to John G. Feldkamp on Aug. 10, 1965, shows and describes an inflatable resilient bag-type device for use as a shoring or dunnage device for merchandise shipped in a transportation vehicle, provided with an inner plastic bag acting as a bladder or air containing member aand outside strength providing layers of relatively strong and inexpensive materials, such as burlap, sisal, rayon, and paper. The use of inexpensive construction materials for the dunnage device provides sufficient economy to permit it to be discarded after a single use, even though it is durable enough for limited repeated use.

Experience with the type of dunnage device described in the patent has revealed a certain diiculty during its ination. When the device is in a flattened condition preparatory to use, the wall of the plastic bladder containing the inflating valve is closely adjacent to the opposite wall of the bladder. As pressurized -air is introduced through the valve, portions of the wall of the bladder opposite the valve and portions of the wall containing the valve proximate to the edge of the base of the valve are strained due to the forces of the in-rushing pressurized air. This is accompanied by vibration as evidenced by a high pitched sound. When the bladder is of polyethylene plastic, these forces may seriously str-ain and weaken the plastic to such an extent that holes are -oftentimes produced, thereby destroying the utility of the dunnage device.

It is the principal object of this invention to improve the construction of such a dunnage device by employing reinforcing means on the bladder wall in the vicinity of the affected portions in order to stiffen the portions and minimize the undesirable effects which damage the device.

In order to achieve this objective, it is still another object to employ a stiffening patch on the inside surface of the bladder portions, said patch providing an inexpensive and simple expedient for this purpose.

It is still another object to provide such a patch which is of inexpensive fabric or paper material covered with a pressure sensitive coating to enable it to be readily applied to the bladder.

Other objects and advantages of the invention should be apparent upon reference to the accompanying drawings in which:

FIG. l shows a perspective view of an embodiment of an inflated shoring or dunnage device manufactured according to this invention;

3,414,140 Patented Dec. 3, 1968 ice FIG. 2 shows a perspective view of the shoring or dunnage device of FIG. l in its deflated condition;

FIG. 3 shows a plan view of the shoring or dunnage device in its deflated position;

FIG. 4 is a left side view of the dunnage device of FIG. 3;

FIG. 5 is a sectional view along the line 5-5 of FIG. 3 and shows the relationship of the various wall layers of the dunnage device, the valve means yfor inflation, and the reinforcing means which substantially eliminates vibration of portions of the bladder;

FIG. 6 shows an open tube of plastic Whic-h, when sealed, forms the plastic bladder used Within the device of FIGS. l and 2; and

FIG. 7 shows an airtight plastic bladder embodying the improvement of this invention.

As shown particularly in FIGS. 6 and 7, the plastic bladder or air containing member 2 used inside the device 1 may be made from a tube 2a of high density polyethylene plastic compounded with butyl-rubber (such as Grax Plastic Co., Division of Allied Chemical Co., Clifton, NJ., compound number 2201) of -an average thickness of six thousandths of an inch and a minimum thickness of about fifty-four ten thousandths (.0054) of an inch. The plastic tube 2a may be cut to size and a reinforcement means such as a square patch of heavy duty pressuresensitive tape can be installed on the inside surface of the plastic tube 2a as shown in FIG. 6. An air valve 4 can be heat sealed at its base 9 to the inside surface of the plastic tube 2a. The tube 2a is then flattened into a double layer condition such that the valve 4 lies directly adjacent and opposite to the reinforcement means 7. Both the forward end 2b and the rear end 2c of the plastic tube 2a are then heat sealed together -along lines 2d and 2e, respectively. With these ends 2b and 2c sealed, the flattened tube is in the shape of a flat enclosure which is, then, an airtight bladder.

Six plies of extensible kraft paper, the outer ply of which can be waterproofed with polyethylene, are then made into a single multi-walled paper tube 3 by overlapping the two edges of each ply which are glued together as indicated at 3a. The paper tube 3 is cut to a length longer than that of the bladder 2.

The airtight plastic bladder 2 is then carefully inserted into the cut-to-length paper tube 3 so that there are no objectionable wrinkles or creases formed in the bladder and such that the valve 4 and the reinforcement patch 7 remain adjacent. The air valve 4 is passed through the central opening 10 of an annular grommet 4c secured to the annular margins of a corresponding opening of the paper plies of tube 3 to provide access to the valve externally of the device. A resilient tight fitting metal fastener 4b is pressed down over an annular notch 4d around the projecting portion of the valve 4 to keep its base 9 urged toward the grommet 4c and fully projecting.

With the reinforcing plies of the multiwall paper tube 3 enveloping the bladder 2, dowel rods y6 and 11 are placed at the ends of the paper tube 3 at regions adjacent the end seals 2d and 2e of the bladder 2. The superimposed layers of the plies of paper of the tube 3 and the walls of the plastic bladder Z are then folded around the dowel rods 6 and 11. Metal edges or end closures 5 and 12 `are then positioned around the portions surrounding the dowel rods 6 and 11. The end closures are preferably tightly squeezed by means of a press to insure a tight grip of the end closures 5 and 12 on the device. This tightening is indicated in FIG. 5 by the movement of the end closure 5 and the bag portions from positions shown in dotted lines to those shown in solid outline.

When the dunnage device 1 is in its iinal assembled form as shown in FIG. 2, it is then lled with air through the valve 4 to a suitable pressure of about four pounds per square inch for ordinary use.

The inflating valve 4 consists of a pin or plunger 13, an annular rubber washer 15 which is secured to the base of the pin 13 by fitting the 'Washer 15 partly into a groove at the pin base, and a spring 14 which forces the pin 13 toward the free end of the valve, thereby forcing the washer 15 against an annular projection 16 of the inside valve wall. A cap plug 17 can be secured on the valve to protect the pin 13 from accidental displacement which can cause air leakage. To inflate the dunnage device, the cap plug 17 is removed from the valve 4 and a source of pressurized air is applied to the valve. Pin 13 is forced downward by the air pressure, providing an opening between the washer 15 and the projection of the valve Wall 16 which permits access of the pressurized air through the valve base 9 to the plastic bladder 2. When the dunnage device 1 is filled to suflicient pressure, the pressurized air source is removed from the valve. The spring 14 forces return of the pin 13 to force the washer 15 against the annular projection 16 L of the inner valve wall, thereby blocking the then pressurized air inside the dunnage device 1 from escaping.

It is during the inflation process that the need of the reinforcement means 7 exits. As best seen in FIG. 5, prior to inflation, one wall of the plastic bladder 2, as indicated in solid outline, is ordinarily positioned directly against the base of the air valve 4. Because the relatively thin gauge plastic bladder 2 is not ordinarily attached (except at the ends of the device) to the inner ply of the paper tube 3, it is ordinarily free to be strained as a result of the incoming stream of high pressure air. Without the patch 7 or other reinforcing means, the forces of the inrushing pressurized air stream oftentimes strain the bladder walls and weaken them sufficiently to rupture the plastic bladder in the regions proximate to the valve to render the dunnage device useless Without its air retaining ability. By installing the reinforcing means 7 made of heavy duty pressuresensitive tape or paper, for example, on the inner wall of the plastic bladder 2 directly opposite the valve 4, the deleterious effect of the forces of the incoming pressurized air can be substantially eliminated,

The dunnage devices described are generally manufactured in various sizes from widths of 36 inches to 47 inches and lengths of 70 inches to 118 inches. The valve 4 described may be of one standard size for all sizes of dunnage devices. The base 9 of the valve may consist of an annulus with an outside diameter of approximately 2 inches and inside diameter of approximately 1/2 inch corresponding to the diameter of the air inlet of the valve.

To eliminate the deleterious condition, various sized reinforcing patches can be incorporated. For example, it has been found that a patch which at least covers the annular base 9 of the valve 4 and which can be larger than the base 9 by any amount will satisfactorily minimize the condition. A patch of 4 by 4 inches is satisfactory for the valve 4 having an annular base 9 with the 2 inch outside diameter and 1/2 inch inside diameter.

I claim:

1. A pneumatic dunnage device for cushioning a load in a transportation vehicle comprising, a longitudinally extending, substantially flat first tube of relatively thin, flexible, synthetic, thermoplastic film material for providing a discrete inflatable, airtight bladder, a longitudinally extending, substantially flat second tube of strong flexible paper, said second tube containing said first tube, a lateral reinforcing strip at each end extremity of said second tube, means securing together the opposite walls of said second tube and said reinforcing strips at the respective opposite ends of said second tube, and valve means on said first tube extending through the wall of said second tube and to the exterior thereof, said first tube being inflatable through said valve means, said second tube being of a size and the paper being of suflicient strength to provide reinforcing backing for all portions of said first tube, when the latter is inflated, to prevent rupture of said first tube when said dunnage device is subjected to impacts from the load, the flexibility of said paper of said second tube permitting said second tube to balloon outwardly in response to pressure in said first tube as it is inflated, and reinforcing means on the inside surface of the first tube positioned directly opposite the location of the valve means, said reinforcing means providing a stiffener for minimizing weakening of the portions on the first tube in regions proximate to the valve means due to the forces on the first tube by the inrushing air when the first tube is being inflated through the valve means.

2. A pneumatic dunnage device for cushioning a load in a transportation vehicle as defined by claim 1 characterized by, said reinforcing means being in the form of a flexible patch adhered to the inside surface of the first tube.

3. A pneumatic dunnage device for cushioning a load in a transportation vehicle as defined by claim 1 characterized by, said reinforcing means being in the form of a flexible and strong patch adhered to the inside surface of the first tube by pressure sensitive means.

Y4. A pneumatic dunnage device for cushioning a load iny a transportation vehicle comprising, a flat inflatable bladder of relatively flexible airtight film material, a flat shroud of strong flexible material enveloping said flat bladder and providing a pillow-shaped reinforcing backing for all portions of the bladder when the bladder is inflated to a pillow shape, valve means on said bladder extending through the wall of the shroud and to the exterior thereof, said bladder being inflatable through the valve means, and other reinforcing means on the inside surface of the bladder confined to a position opposite the location of the valve means and ordinarily in close proximity to the valve means when the bladder is in its flat condition, said other reinforcing means providing a stiffener for the bladder in the region of its position on the bladder for minimizing Weakening of the portions of the bladder in regions proximate to the valve means due to the forces on the bladder caused by the inrushing air passing between the valve portion of the bladder and the other reinforcing means in close proximity thereto when the bladder is being inflated through the valve means.

5. A pneumatic dunnage device for cushioning a load in a transportation vehicle as defined by claim 4 characterized by, the valve means having a hollow elongated substantially cylindrical body with a central bore through which the inflating air passes, a relatively rigid annulus extending radially outward from the base of the valve, said annulus being joined by an airtight connection to one wall portion of the bladder, said reinforcing means positioned opposite the location of the valve means being of an area large enough to substantially extend over the entire area of the annulus when the dunnage device is in its flattened and deflated condition.

6. A pneumatic dunnage device for cushioning a load in` a transportation vehicle as defined by claim 4 characterized by, the valve means having a base stiffer than the film material of the bladder extending radially outward from the valve, said base being joined by an airtight connection to one wall portion of the bladder, said reinforcing means positioned opposite the location of the valve means being of an area large enough to substantially extend over the entire area of the base when the dunnage device is in its flattened and deflated condition.

7. A pneumatic dunnage device for cushioning a load in a transportation vehicle comprising, a flat inflatable bladder of relatively flexible airtight film material, a shroud of strong flexible material enveloping said bladder and providing a reinforcing backing for all portions of the bladder when the bladder is inflated, valve means on said bladder extending through the Wall of the shroud and to the exterior thereof, said bladder being inflatable through the valve means, and reinforcing means on the inside surface of the bladder opposite the location of the valve means, said reinforcing means providing a stiffener for minimizing weakening of the portions of the bladder in regions proximate to the valve means due to the forces on the first tube by the inrushing air when the bladder is being inflated through the valve means said reinforcing means being in the form of a flexible patch adhered to the inside surface of the bladder.

8. A pneumatic dunnage device for cushioning a load in a transportation vehicle comprising, a flat inflatable bladder of relatively flexible airtight film material, a shroud of strong flexible material enveloping said bladder and providing a reinforcing backing for all portions of the bladder when the bladder is inflated, valve means on said bladder extending through the wall of the shroud and to the exterior thereof, said badder being inflatable through the valve means, and reinforcing means on the inside surface of the bladder opposite the location of the valve means, said reinforcing means providing a stiffener for minimizing weakening of the portions of the badder in regions proximate to the valve means due to the forces on the first tube by the inrushing air when the bladder is being inflated through the valve means, said reinforcing means being in the form of a flexible and strong patch adhered to the inside surface of the bladder by pressure sensitive means.

9. A pneumatic dunnage device for cushioning a load in a transportation vehicle comprising, a flat inflatable bladder of relatively flexible airtight film material, a shroud of strong flexible material enveloping said bladder and providing a reinforcing backing for all portions of the bladder when the bladder is inflated, valve means on said bladder extending through the wall of the shroud and to the exterior thereof, said bladder being inflatable through the valve means, and reinforcing means on the inside surface of the bladder opposite the location of the valve means, said reinforcing means providing a stiffener for minimizing weakening of the portions of the bladder in regions proximate to the valve means due to the forces on the first tube by the inrushing air when the bladder is being inflated through the valve means, said reinforcing means being in the form of a flat disc-shaped patch adhered to the inside surface f the bladder to effectively thicken the wall of the bladder in the region of the patch.

10. In an airtight pneumatic bladder of relatively flexible airtight material in the form of a tube which can be flattened with two opposite wall portions of the tube in close proximity to each other, one of said wall portions having a valve means through which the bladder can be inflated, comprising, a reinforcing means on the second of the two wall portions confined to a location opposite that of the valve means and ordinarily in close proximity to the valve means whenithe bladder is flattened, said reinforcing means providing a stiffener for the bladder in the region of its position on the bladder for minimizing weakening of the portions of the bladder in the regions proximate to the valve means due to the forces on the bladder caused by the inrushing air passing between the valve portion of the bladder and the reinforcing means in close proximity thereto when the bladder is being inflated through the valve means.

11. A pneumatic dunnage device for cushioning a load in a transportation vehicle comprising, a longitudinally extending, substantially flat first tube of relatively thin, flexible, synthetic, thermoplastic film material for providing a discrete inflatable, airtight bladder, a longitudinally extending, substantially flat second tube of strong flexible paper, said second tube containing said first tube, said first and second tubes being closed at their ends, and valve means on said first tube extending through the wall of said second tube and to the exterior thereof, said first tube being inflatable through said valve means, said second tube being of a size and the paper being of suflicient strength to provide reinforcing backing for all portions of said first tube, when the latter is inflated, to prevent rupture of said first tube when said dunnage device is subjected to impacts from the load, the flexibility of said paper of said second tube permitting said second tube to balloon outwardly in response to pressure in said rst tube as it is inflated, and reinforcing means on the first tube positioned directly opposite the location of the valve means and ordinarily in close proximity to the valve means when the first and second tubes are in their fiat conditions, said reinforcing means providing a stiffener for the first tube in the region of its position on the first tube for minimizing weakening of the portions on the first tube in regions proximate to the valve means due to the forces on the first tube by the inrushing air passing between the valve portion of the first tube and the reinforcing means in close proximity thereto when the first tube is being inflated through the valve means.

References Cited UNITED STATES PATENTS 2,207,212 7/ 1940 Arey 137-223 XR 2,297,994 10/ 1942 Vellinga 15 0-9 XR 2,601,568 6/ 1952 Sussenbach et al 229-65 3,199,689 8/ 1965 Feldkamp 214-10.5

GERALD M. F ORLENZA, Primary Examiner. F. E. WERNER, Assistant Examiner.

Images