US2734623A

US2734623A - Packaging of explosives

Info

Publication number: US2734623A
Authority: US
Priority date: 1955-08-29
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14
Also published as: GB773760A

Description

Feb. 14, 1956 c. R. PULLUM ETAL PACKAGING OF EXPLOSIVES Filed Nov. 19, 1955 .w, w v

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2,734,623 1C Patented Feb. 14, 1.9.56

PACKAGING F .EXPLOSIVE'S Cecil R. Pullum, Alton, and Thabus R. Harvey, East Alton, 111., assignors to Olin Mathieson Chemical! Corporation, a corporation of Virginia Application November .19, 1953, Serial No. 393,164

Claims. (Cl. '206-3) This invention relates generally to the packaging of explosives, and particularly to the packaging of primers for ammunition and blasting caps.

Primers of the character referred to comprise a charge of heator impact-sensitive explosive composition contained Within a cup (in the case of primers for ammunition) or other cavitied device such as a plug (in the case of primers for blasting caps). These are conventionally packed, shipped, and handled in packages corresponding substantially to the disclosure of U. S. Patent No. 739,487, although it is common to construct the container of wood, and the partition pieces are commonly made of wood strips. Large primers for military ammunition and military detonators have been packed in a package which employs a separator consisting of a paperboard sheet containing evenly spaced holes, or cells, in which the primers are inserted. The individual packages usually contain between fifty and a thousand primers, and it is common practice to handle and ship .such individual packages in cases containing from ten to a hundred such individual packages.

The containers heretofore used for .the handling and shipping of such primers alford no protection against mass explosions in the event that an individual primer in a case should explode. For example, if an individual primer in the .conventional primer package aforesaid be exploded by an electric spark, or by fire, the whole .mass of primers in the individual package with that primer, and all adjacent packages in a case, will detonate en masse producing a devastating explosion which would propagate to other primers .stored .in adjacent cases. Frequently, such primers are shipped in lots of hundreds of thousands-it is not at all uncommon for boxcar loads or truck loads of several million such primers to be shippedand consequently, the handling .and .shipping in such cases involves such a serious hazard as to flirt with disaster.

The object of the invention generally stated is to provide a package in which primers may be handled and shipped with greater safety than has heretofore been possible.

A more specific object of the invention is to provide a package containing primers in which the likelihood of mass explosion as a result of detonation of an individual primer is minimized.

In accordance with the present invention generally stated, a package is provided for accommodating such primers each in an individual cell. The primers are fitted into the cells so that the end of the primer cup from which the flame or hot gases emerge upon detonation (hereinafter called the open end of the primer) is superimposed by a thin sheet of paper of strength .suflicient merely to hold the primer in its cell. Aligned with each primer-occupied cell, and .on the other side of said sheet of paper, is a substantially similar cell which is empty. By arranging such an empty cell in axial alignment with a primer-occupied cell, detonation of the primer will puncture the layer of paper which intervenes between the primer-occupied cell and the empty cell; but the space provided by the empty cell will sufiiciently dissipate the energy of detonation of an individual primer that explosion f neighboring primers will seldom ensue, and the possibility of mass detonation is substantially avoided.

The cell-forming members are preferably in the form of paperboard sheets Whose thickness corresponds substantially to the axial dimension of the primer. These sheets may be perforated to provide holes of diameter substantially corresponding to that of the primer, said holes being arranged on centers at least about a diameter and a half apart. The primers are similarly orientated in each of a multiplicity of holes in such a sheet so that the open ends of the primers all face in the same direction. When such a cell-forming member has been loaded with primers, the unladen cell-forming member with the intervening layer of paper is applied so that an empty cell is aligned with each primer; and the assembly of sheets may then be enclosed in any suitable container such as a slide type paperboard carton.

One embodiment of the present invention is illustrated in the accompanying drawings in which:

Figure l is a perspective view of a package constructed in accordance with the present invention, part being broken away to reveal the relationship of the several parts and the disposition of the primers therein;

Figure 2 is a sectional view taken along line 2-2 of Figure 1; and

Figure 3 is a plan view of one of the cell-forming members constituting an element of the package shown in Figure l.

The package shown in Figure 1 consists of a paperboard vtray 1, slideable endwise into and out of a paperboard sleeve 2. In the bottom of the tray 1, there is disposed a cushioning layer .of paperboard 3 about .031 inch thick. Immediately above the pad .3, preferably secured thereto as by gluing, is a cell-forming member 4, likewise made of paperboard. As clearly shown in Figure 3, the cell-forming member 4 is provided with 'a series of spaced holes 5. The entire area :of member 4 is preferably provided with such holes :5 which are :of a diameter substantially the same as that of the primer intended to be accommodated therein, and the holes are spaced apart a distance of about a diameter and a half or more. 'In the embodiment shown, the member 4 is 10% x 6% inches, and is perforated with five hundred holes arranged in lengthwise rows of twenty-six or twenty-seven holes each. The thickness of the ce1lforming member 4 is approximately equal to, or slightly greater than, the axial dimension of the primer to be accommodated therein.

Having connected the pad 3 to one side of the cellforming member 4, each of the holes 5 constitutes a closed-bottom cell for snugly receiving a primer such as 6, and a primer is consequently placed in each of the holes 5. For convenience, the placement of the primers 6 in the holes 5 preferably takes place before the member 4 with its associated pad 3 is placed in tray 1; but it will be understood that, if desired, the cellfilling operation may be carried out after the members are placed in the tray 1, in which event the securing of the pad 3 to member 4 may be dispensed with, or in fact, depending upon the resiliency characteristics of the tray 1 and sleeve "2., the pad 3 may be dispensed with entirely.

After having filled each. of the cells 5 with a primer 6 an upper cell-forming member 7 having a series of holes 8 arranged exactly as 'in member 4 may be applied over member 4 within tray 1 with a layer of paper-9 intervening. For convenience, the paper layer .9 maybe glued to one side of member 7 before the latter is inserted in the tray. The paper 9 is preferably 'on the order of .O02.003 inch thick and is of strength sumcient to retain the respective primers 6 in holes during shipping and handling.

After the member 7 has been inserted in tray 1, the latter may be inserted within sleeve 2. A number of such cartons may then be packed in a suitable case which is usually made of wood.

As indicating the capacity of the package above described to minimize mass explosions, the following test data are illustrative.

Test A A number of individual cartons of the type hereinbefore described, each containing five hundred caps, were tested by energizing one electric cap per carton from a suitable electric source. In each instance, the cap so energized detonated, but no neighboring caps fired and the carton was not disrupted.

Test B A wooden box containing twenty-six cartons (each containing five hundred primers) of the type hereinbefore described, said cartons being arranged in two tiers of thirteen each, and each alternate carton containing one cap wired for detonation, was subjected to tests by energizing the individual wire caps one at a time. In the first test, the first seven individual caps to be detonated had no effect upon the neighboring caps, but the eighth blew the box apart. In a second test (with a new box) all caps detonated individually without affecting any neighboring caps or affecting the cartons, or the wooden box. In a third test, the first two caps to be energized detonated without affecting their neighbors. The third cap blew the box apart and the box was then repacked as none of the adjacent cartons had been affected by the explosion. The wired cap in the fourth through the eleventh cartons were then individually detonated with no effect upon neighboring caps. The wired cap in the twelfth carton upon being detonated did blow the box apart. In none of the instances wherein the box was blown apart were the caps in cartons other than that containing the wired cap affected, and then only to the extent of a few immediately adjacent the wired cap. Consequently, even where the box was blown apart, the explosion was not of such magnitude as to have disastrous portent.

Test C A wooden box containing twenty-six cartons as in Test B was set on two rocks and a fire built underneath. The first explosion (apparently of an individual primer) occurred after twenty minutes. A second explosion occurred a half minute later in which fourteen of the twenty-six cartons were blown clear of the fire and did not detonate. Following this second explosion, individual primers which had not been blown clear of the fire popped singly or in small groups. In no instance did more than one or two complete cartons explode at a time.

In contrast, a wooden box containing twenty thousand primers packed in the conventional manner in wooden separator trays (each containing one hundred primers) was tested by wiring one primer in the entire wooden box and energizing it from a suitable electric source. Detonation of that one primer completely destroyed the entire box.

As demonstrating the adequacy of the carton hereinbefore described to withstand mechanical shocks, a box of primers of the character referred to in Tests B and C above was dropped ten times on to concrete from an elevation of four and a half feet, and twice from an elevation of nine feet, without firing or spilling any primer. In the second fall from a height of nine feet,

however, the wooden box split, but no damage resulted to the individual cartons. A number of individual cartons, each containing five hundred of the primers, were likewise dropped one at a time from an elevation of ten feet with no primer detonating and none spilling.

While in the tests above described, the several components of the carton were not in any way flame proofed, it will be understood that application to the several paperboard components, particularly the sheet 9 and the cell-forming members 4 and 7, of a conventional flame retardant may be desired in some circumstances, and such is within the contemplation of the invention. The several paperboard components may be formed by laminating layers one upon the other to achieve the desired thickness, and while it is preferred to use a relatively soft paperboard for components 4 and 7, such is not essential. It is desirable, however, in the selection of the paperboard components, to choose those which are free from materials having a tendency to tarnish the alloys from which the primer cups are usually made.

From the foregoing description, those skilled in the art should readily understand that the present invention accomplishes its objects and, to a very marked extent, reduces the hazard in handling and shipping large quantities of primers. While one complete embodiment of the invention has been described in detail, it is to be understood that such disclosure is merely illustrative and that the invention is not limited to the details of the embodiment described. Consequently, such modifications and variations as present themselves to those skilled in the art without departing from the spirit of the invention are contemplated by and within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A prepared package comprising a member having a plurality of spaced cells, .an explosive-laden device in each cell, said cells and devices substantially corresponding in size and shape, means for confining the devices wholly within said cells, another member having a plurality of cells arranged in alignment with the cells in'the first named member, the cells in the last named member being void and on the opposite side of said means from said explosive-laden devices.

2. A prepared package comprising, a pair of confining members each provided with a plurality of spaced cells arranged in the same pattern, the cells of said members being aligned, a layer of rupturable material between said members, explosive-laden devices in some of said cells, one only of each pair of aligned cells being occupied by an explosive-laden device, and closure means for retaining said parts in the relationship aforesaid.

3. The package of claim 2 wherein the individual cells are proportioned to snugly receive the explosive-laden devices.

4. The package of claim 2 wherein the layer is paper.

5. The package of claim 2 wherein the explosive-laden devices each have an open end and a closed end, and wherein the open ends thereof are adjacent said layer.

6. The package of claim 2 wherein the explosive-laden devices are all in one of said members, and the cells in the other member are all void.

7. The package of claim 2 wherein the members and layer are of paper-like material which has been treated with fire retardant.

8. A prepared package containing explosive-laden devices, and comprising a tray, a layer of paperboard in said tray, said layer having a thickness at least as great as the axial dimension of said devices, said layer having a series of spaced perforations of size and shape corresponding substantially to the radial cross-section of said devices, an imperforate layer of paperboard in said tray and closing one end of said perforations, said devices occupying said perforations, another layer of paperboard in said tray and having perforations arranged in the same pattern as the perforations in the first layer, said perforated layers being arranged with their perforations in alignment respectively, a layer of imperforate rela- 5 tively thin paper intervening said perforated layers, and closure means for retaining said layers in position in said tray.

9. The package of claim 8 wherein the devices have an open end and a closed end, and the closed ends thereof 6 are adjacent said imperforate layer of paperboard.

10. The package of claim 8 wherein the perforations in said members are spaced apart, center to center, a distance of at least 1.5 diameters of the explosive devices.

References Cited in the file of this patent UNITED STATES PATENTS