US2911910A - Blasting assembly - Google Patents

Description

Nov. 10, 1959 WELSH, JR 2,911,910

BLASTING ASSEMBLY Filed Aug. 8, 1956 fir 1 INVENTOR RICHARD F. WELSH JR.

St ts Pater 2,911,910 Patented Nov. 10, 1959 BLASTING ASSEMBLY Richard F. Welsh, Jr., Martinsburg, W. Va., assigrror to E. I. du Pont de Neurons and Company, Wilmington, Del., a corporation of Delaware Application August 8, 1956, Serial No. 602,784

2 Claims. (Cl. 102-24) The present invention relates to a blasting assembly particularly adapted for use in inaccessible locations. More particularly the present invention relates to a blasting assembly which may be placed at an inaccessible location by means of a long pole.

Certain methods of low cost mining are based on the principle that broken rock or ore will flow by gravity down inclined passages or chutes hollowed out of virgin rock. By this method, ore can be transferred cheaply from the source area to another where it is loaded, either directly or indirectly, into mine cars. It is important in such an operation that the maximum size of the particles to be transferred be small enough relative to the minimum dimension of the passage so that the chunks of rock or ore will flow freely. Despite the fact that such factors are taken into account in the design of these passageways, they frequently do become blocked and cease to function. On occasion, rock jams will occur which bridge the passage and clog it. Sometimes, chunks of ore or rock, which are too large to enter the opening, become lodged in the mouth of the passageway. When any of these conditions occur, it is necessary to remove the obstruction by blasting.

For many years the practice to relieve such obstructions was for the shot firer to make a hazardous approach to the jam from below in order to secure an explosive charge in the proper position adjacent thereto. This charge, when detonated, broke up the constriction and permitted the mining operation to continue. This was obviously a dangerous practice since the safety of the operator during his ascent depended upon the jam holding fast.

In more recent times the practice has been for the operator to tie an explosive charge to a long pole, insert the initiating means, i.e., -a blasting cap or a length of detonating fuse into the explosive charge, and wedge the pole in such a position that the charge is properly located near the jam. Since this technique does not require the operator to remain under the rock jam for an extended period, it is a good deal safer. The tying operation, however, is time consuming and inconvenient, and considerable skill is required to tie the explosive charge or charges in such a manner that they do not become dislodged while the pole is being maneuvered into the desired position.

Accordingly, an object of the present invention is to provide a blasting assembly adapted for rapid and simple mounting on a pole. An additional object of the invention is the provision of a blasting assembly of this type which is inexpensive, convenient, and safe to use. Other and additional objects will become apparent as the invention is more fully hereinafter described.

I have found that my objects are achieved when I provide a blasting assembly having a bag-like container which consists of a pair of flexible generally concentric, coextensive sleeves formed integral at one end only and remaining open at the other end. Such a container may be conveniently formed by pulling a hollow sleeve of flexible material through itself for one-half of its length. All or a portion of the annular space thus formed is then filled with a suitable blasting agent or explosive composition, such as dynamite or the like, and the ends of the sleeve are then gathered and tied to provide a pocket for the reception and retention of a positioning pole. By means of the positioning pole, the package may be elevated to a lofty position and disposed adjacent to a rock jam or similar constriction. To more fully illustrate the invention, reference is now made to the accompanying drawings in which:

Figure 1 represents an elevational view of the sleeve which forms the container for the assembly;

Figure 2 illustrates the sleeve of Figure 1 after it has been pulled through itself for one-half of its length;

Figure 3 is a top view of Figure 2;

Figure 4 is an elevational view of the sleeve of Figure 2 after it has been loaded and tied;

Figure 5 is a bottom end view of the package of Figure 4;

Figure 6 shows the package of Figure 4 mounted on a positioning pole; and

Figure 7 is a cross-sectional View of the assembly of Figure 6 taken along the line 7--7.

In the drawings, 1 represents a sleeve of flexible packaging material such as cloth, burlap, polyethylene film, or the like. The sleeve is open at both ends 2 and 3.

Figures 2 and 3 depict the sleeve 1 after it has been pulled through itself for one-half of its length forming, in effect, a pair of flexible generally concentric, coextensive sleeves formed integral at their bottom end and remaining open on the top end. The ends 2 and 3 are now on the same side and an annular space 4 is thus formed for reception of a blasting composition. The latter may be a high explosive composition, such as dynamite or TNT, or it may be a less expensive blasting agent, such as any of the sensitized ammonium nitrate compositions which are well-known in the blasting arts. As seen in Figure 3, the sleeve itself is now of double thickness but is still hollow, as at 5.

The blasting composition is loaded into the annular space 4, preferably, but not necessarily, over about onehalf of its circumferential extent as illustrated at 9 in Figure 7. The ends 2 and 3 of the sleeve are then gathered and securely tied as by a wire or cord 6. The tie serves to seal the blasting composition 9 in the annular space 4 and to close off the top of the center space 5 providing a pocket for reception and retention of a positioning pole. The pole 8 is inserted from the bottom into the mouth of the said pocket, indicated at 7 in Figure 5. It penetrates all the way up into the pocket until it abuts the bag tie 6 which prevents it from passing any further. The assembly is now securely mounted on the pole and may be maneuvered without fear of its becoming easily dislodged.

In use, the assembly is mounted on a pole as illustrated in Figure 6. A blasting cap or other detonator may be tied to the neck of the package when necessary. The package is then elevated to a position adjacent the rock jam or constriction which is to be blasted and the blasting composition is detonated.

The particular material selected for the sleeve is not a critical feature of the present invention. Any flexible packaging material which will not easily tear or fracture under the conditions of use is suitable, such as heavy textile materials, plastic and rubber films, and the like. The latter have the advantage of being substantially impermeable to moisture. l have found that cotton cloth or burlap laminated to a thin polyethylene film is especially suitable. The polyethylene (on the inside) serves 3 as a moisture barrier while the outer cloth or burlap provides additional strength.

In lieu of the bag tie 6, any other suitable closure may be used provided 'it is of sufficient strength to-resist-tearing-open when the assembly is loaded on a pole. For example, the ends fo the sleeves may be taped or stapled shut instead of tied.

The positioning pole 8 may be wood or plastic or other similar material. In many cases it may be convenient to use a long branch or sapling which is found in the area.

The precise nature and amount of the blasting composition used is not a critical feature ofrthe invention and will vary greatly, in practice, depending upon the material to be blasted. Generally speaking, any readily available commercial blasting composition is operable.

It will be readily apparent from the foregoing that the blasting assembly of the present invention is a cheap, safe,

W efiective assembly which may besecurely loaded on the end of a long pole for elevation and positioning at a lofty inaccessible point.

The invention has been clearly'disclosed in the foregoing specification. It will be expressly understood, however, that many variations in the details of construction, materials, assembly, and dimensions of parts may be made without departing from the scope or spirit of the invention. I intend to be limited, therefore, only by the following claims:

I claim:

,1. A blasting assembly comprising a pair of flexible generally concentric, coextensive hollow sleeves formed integral at one end only, a blasting composition in the annular space formed by the walls of said concentric 4 sleeves, the open ends of the sleeves being bound securely shut to close off the open upper end of said annular space containing the blasting composition and to provide a pocket closed at the top and open at the bottom for the reception and retention of a positioning pole in the center of said concentric sleeves, and-a-positioning pole in said pocket.

2. A blasting assembly comprising .a pair of flexible generally concentric, coextensive hollow sleeves formedintegral at one end only, 'a blasting composition in the annular space formed by the walls of said concentric sleeves, the open ends of the sleeves being tied to close ofi the open upper end of said annular space containing the blasting composition and to provide a pocket closed at the top and open at the bottom for the reception and retention of a positioning pole in the center of said concentric sleeves, and a positioning pole in said pocket.

References Cited in the file of this patent UNITED STATES PATENTS- Great Britain Sept. 21, 1955

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