US2311721A - Blasting explosive assembly - Google Patents

Description

Feb. 23, 1943. w, F, w'lLsON 2,311,721

` BLASTING EXPLOSIVE ASSEMBLY Filed May 4, 1939 Patented F eb. 23, 1943 NITE . Ij ASSEY William F. Wilson, Newark, Del., assigner to Atlas Powder Company Wi corporation of Deia Application May 4, X939, Serial No. 271,772

9 Claims. invention relates to improvements in blasting explosive assemblies. and more particularly to improvements in explosive assemblies of l. l.

the general character oi those described in U. S.

` Letters Patent to Carl D. Pratt, No. 1,785,529.'

The aforesaid patent discloses the many important advantages ilowingnirom an -assembly having a core of high explosive materiahfsuch' as dynamite. and abody of low explosive, such as black powder, surrounding said core. By virvided in which there is incorporated the sensitivity and strength of the high explosive'core, with the reliability, safety, and non-shattering explosive action oi the black powder.

powder incorporated in the form oi pellets, the high explosive core material being co-extensive in length and individual ito the severalpellets.

In such an arrangement. there is little likelihood oi the dynamite getting out oi longitudinal alignment, because the pellets themselves, when enl' closed in a suitable wrapper, are .of such a na-v ture as to maintain their position and thereby maintain the position of the dynamite of the.

COTS.

i The present invention proposes .to employ a.,y suitable container having a central core consisting of two or more sticks of dynamite disposed end to end in longitudinal alignment, with a to end relation to each other.

It is also contemplated to utilize this idea of a centering means for a plurality of superim-v posed sticks of dynamite in a bag-like container, the walls o! which are made of waterproof and extensible material. When used in such a container, the central tube not only serves its function of centering the sticks of high explosive material, but it aids in preventing such localized impacting oi the black powder as would tend to produce such localized bulges upon the exterior of the container as would interfere with the proper loading oi' the explosive assemblies into bore holes.

The body of black powder which surrounds the superimposed sticks of high explosive is not separated into distinct layers, as in the case of pelleted black powder, but comprises a illled-in. homogeneous mass which in length eduals the combined length oi' the sticks of high explosive. If it were attempted to place a plurality oi sticks of high explosive in longitudinal alignment without some means of maintaining the position of these sticks in the body of black powder, it is almost certain that in handling and transit,

tue of such a combination, an assembly is pro 15. However, the Pratt patent discloses the black some of these sticks would get out of line. They might lie obliquely of the package. or they might assume positions where they would lie wholly or partly side by side.

Any such dislodgement of the=high explosive core would be highly undesirablabecause one of the important functions of this central core is to propagate the explosive wave from one detonator assembly to another when a. plurality of'them are loaded into a bore hole on top of each other. The closer the end of the high explosive core of one assembly lies to the end of the corresponding core oi another assembly, the more reliable and certain will be the action of the detonatng Wave through the whole group of assemblies.

It will be seen that my proposed arrangement etllciently serves' to accomplish this proper positioning of the units of the highv explosive core with respect to each other. Further objects and advantages of the invention will be setiorth in theV detailed description which follows. Y

In the accompanying drawing: Figure l is a sectional view of anexplosive assembly employing a bag-like container of ei:- tensible material; Fig. 2 is gne-2 0f Fig 1:: f Fig. 3 is a horizontal sectional view a modified form of spacing element;

.30 Fig. t is a magnliled View illustrating a sec-A tion ot theextensible-,walloi the bag-like con# :einer of Fig. Lana y "an assembly employing a rigid container. Like numerals indicate-corresponding parts in all of thegures of the drawing. i

' In the drawing, l designates a bag-like-recep- I tacle that is tied at the top by-a conventional Q twisted wire loop 2. lThis loop embodies the conr- 40 ventional eye 3 by which the assembly-may be A body of vgral-.mier black powder d surrounds a tube 5, said tube belowered into a bore hole.

ing held in centered relation'within the bag by annular spacers 6. 'I'hese may be made of cardy board, Celluloid, or any other suitable material.

When made of Celluloid, they have the advantage that they may be consumed along with the explosive charge.

uThe tube receives a plurality of sticks, usu# ally two or three, l, of high explosive material' such as dynamite. Referring now to Fig. 4, i designates a web of extensible paper, or the nature of crepe paper, for example. This paper is covered by a. coating of a suitable water-prooilng 'composition lb, such as latex, asphalt, or the like. This material Ib is not only water-proof, but it is suihciently adhesive to closely unite an outer web of woven fabric ic to the paper web la.

The fabric i gives a considerable degree of o0 strength to the walls of the container without illustrating ahorizontal sectional view upon'line l Fig. 5 is a vertical sectional-view illustrating y v impairing the iiexibility and extensibility of the material of said walls. Thus the assembly as a whole has such a degree of flexibility and elasticity as will best adapt it to be tamped tightly into bore holes. At the same time, in the absence of tamping pressure, the outer wall or the container maintains its straight line form to adapt it to be lowered into bore holes without catching upon the sides of the hole.

This straight line formation of the otherwise easily deformed container I is maintained in part by the presence of the tube 5. This tube aids in maintaining a more uniform impacting oi the black powder and aids in preventing localized density variations in said powder, such as might tend to cause localized bulges of the extensible wall I,

The structure illustrated in Fig. '3 is substan tially like that already described, except that in lieu of the solid spacers t, I employ a wire spacing element t which serves to maintain the tube 5 in centered relation to container i. This spacer 6a has the advantage that the black powder may be iilled into the container with this spacer in place, because this spacer is an open one through which the black powder may pass.

It will generally be desired to employ a container having extensible walls, because of the advantages arising from the capability o! assemblies employing such containers to be tamped into and conform to the contour of the bore holes in which they are placed or to the contour of the other assemblies which go to make up a large charge. However, it is within the purview of the invention to employ a rigid outer container if desired, and such an arrangement is illustrated in Fig. 5.

Here the low explosive charge is indicated at 8, and the sticks of high explosive are indicated at 9a, 9b, 9, and it is also indicated that these explosive sticks may have individual wrappers td.

In this case, the outer container I0, of tubular formation, is closed at its lower end by a cap II. This cap may be provided with an upstanding annular iiange I2 to receive and position the cen tral tube I3 by which the high explosive sticks are aligned.

The upper end of this tube is positioned in a corresponding ilange I4 rupon a cap I5. The as semblies of both Figs. -1 and 5 may be dipped in paraffin after completion to aid in sealing them and rendering them wholly water-proof.- The container of Fig. 5 will be of somewhat can-like formation and may be made of tin, paper, Celluloid, or any other suitable material.

Where the container I0 and its caps Il'and It are made of pyroxylin compositions, they have the advantage of being consumed along with the remainder of the charge. With this end in view, I may make the tubes E and I3 of pyroxylin ma.- terials which, while having sufficient strength to serve their function of centering, may be quickly consumed along with the remainder of' the charge v and thus avoid an undue amount oi smoke.

I may, in the construction of Fig. l, employ dynamite sticks 'l either with or without wrapn pers. Conventional sticks of dynamite are eight inches in length, and I contemplate utilizing these conventional sticks oi dynamite in the manufacture of the explosive assembly of this invention.

It is to be understood that the invention is not limited to the precise constructions shown, but

that it includes within its purview whatever changes fairly come within either the terms or the spirit oi the appended claims.

i Having described my invention, what I claim 1. In an explosive assembly, a container, a. tubular member extending lengthwise through said container, a plurality of sticks of high explosive disposed end to end within the tubular member, and a. continuous mass of loose, low explosive within the container and surrounding said tubular member.

2. A structure as recited in claim l, in combination with spacing members bearing between the container wall and the tubular member by which the tubular member is held in substantially centered relation within the container.

3. A structure as recited in claim 1, in combin nation with a spacer for holding the tubular member in centered relation in the container, said spacer being o open formation to permit the passage of the ow explosive therethrough in nlling the container.

4. In an explosive assembly, the combination with a high explosive core consisting of a plurality of conventional sticks of dynamite disDOSed end to end in contacting relation, of a centering tube within which said sticks of dynamite are located, `an elongated bag-like container ot a. length equal to the combined length of the sticks of dynamite, the walls of which container are of extensible and water-proof material, and a body of low explosive completely iilling the space within the bag around said tube and presenting a oontinuous and unbroken body of said low explosive ofia length to overlap all of said sticks of dynam te.

5. A structure as recited in claim 4, in combination with means vfor centering the tube in the container.

6. In an explosive assembly, the combination with a high explosive core consisting oi' s. plurality of conventional sticks of dynamite disposed end to end in contacting relation, ol' a centering member within which said sticks of dynamite are located, an elongated bas-like container o! a,

length equal to the combined length or the sticks of dynamite, within which said dynamite sticks and centering member are located, the walls of which container are oi' extensible material, and a body of low explosive completely filling the space within the bag around said centering member and presenting a continuous and unbroken body of said low explosive o! a length to overlap all of said sticks of dynamite.

'1. A structure as recited in claim 6 wherein the centering member is formed or `combustible material.

8. A structure as recited in claim 6, vwherein the extensible wall of the container comprises an internal layer of extensible paper, an external layer of extensible woven fabric, and an intermediate uniting layer of water-proof cementltious material between the paper and fabric.

9. In an explosive assembly the combination with ani elongated bag-like container oi water-,- proof material, of a plurality of sticks of high explosive disposed end to end lengthwise of said container and substantially centrally therein, and an aligning means of a length to overlap a plurality of said sticks of high explosive, engaging said sticks of explosive and holding them from shifting laterally out of alignment with each other, and a body of granular low explosive surrounding the high explosive and substantially nlling the container.

WILLIAM F. WILSON.

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