US431747A

US431747A - Art of blasting

Info

Publication number: US431747A
Authority: US
Publication date: 1890-07-08
Anticipated expiration: 1907-07-08

Description

(No Model.)

J. A. KURTZ. ART OP BLASTING.

nnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn cA Patented July 8, 1890! i "UNITED STATES PATENT OFFICE.v

JOHN A. KURTZ, OF PITTSBURG, PENNSYLVANIA.

ART OF BLASTING..

'SPECIFICATION forming part of Letters Patent No. 431,747, dated July 8, 1890.

Application filed October 2, 1889. Serial No. 325,784. (No model.)

To all whom it .may concern:

Be it known that I, JOHN A. KURTZ, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in the Art of Blasting and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

The object of the invention is to simplify and cheapen methods of and devices for blasting rock heretofore employed, and particularly those methods the purpose of which has been to direct the force of explosion in such manner as to produce fracture along predetermined lines. One method of this has been to drill a circular hole in the rock, as usual, and then to forni grooves continuous with the hole and along the lines in which it was desired to split the rock. This mode increases the labor of drilling and requires special tools for the purpose. This eXtra labor and the use of such particular tools is avoided by my invention, which consists in the matter hereinafter set forth and particularly pointed out.

In the accompanying drawings, Figure l is a central section in vertical plane on line X X of Fig. 2 of a charge partition and tamping located in a bore in rock. Fig. 2 is an enlarged transverse sect-ion of the same on line Y Y, the bore in the rock being indicated by the circle. Figs. 3, 4, and 5 are similar views of modifications of the partition. Fig. 6 is a partial vertical section in a plane through the longest diameter of a partition, showing location of fuse in the partition; Fig. 7, a like View showing means for introducing the partition. Fig. 8 is atransverse section showing another form of partition or bar, and Fig. 9 is a cross-section of a bar made in two parts to provide for the ready insertion of fuse.

The figure of reference l indicates a rod, bar, or strip of any convenient materialsuch as wood or iron-placed in' a drill-hole of usual form in a manner to act as a partition and divide the charge 2 of exploding material. Said dividing-bar has its edges 3 near or in actual contact with the surface of the rock. This partition may be first inserted and the powdersubsequently charged 5 or the partition may be forced down through the powder previously introduced, the foot of the partition having been suitably sharpened for u this purpose.

At 6 in the bottom of the bore, and below the powder, is indicated a small quantity of dirt or like material, which is employed for the purpose of preventing the dividing-bar from being thrown out by the explosion. It tends to exclude the expanding gases from passing down below the bar and acting against its post in a vertical direction.

The form of the partitions may be varied. A few of the possible modifications are indicated in the drawings. They may be made rectangular in cross-section, or their several faces, the number of which can be two, three, or more, may be made either convex or concave. Their function isto divide the explosive and to direct the force of explosion in such manner as to fracture the rock-bed in planes passing through the edges of the partition. These edges may be in actual contact with the face of the bore or may be removed a slight distance and sufiiciently to permit ignition between the edge of the partition and the rock.

Figs. 2, 3, and 5 illustrate dividing bars or partitions, having each two edges or lines of contiguity with the face of the bore, and Fig. 1.1. exhibits four such lines or edges.

In Fig. 6 is shown a fuse, passing dow-n through the bore in a dividing-bar. It can be introduced, however, in any convenient manner. For example, a slot may first be made in the bar which will admit the fuse sidewise,

which slot can be closed outside the fuse by a piece of material fitted therein; or the partition can be made in two parts, one or both of which is suitably grooved to receive the fuse, as indicated in Fig. 6, and these may be yfastened together in any convenient manner.

In case the partition extends to the top of the bore, or above it, as indicated in Fig. 6, a cap or washer 4C may be secured upon it within the bore in the rock to sustain the tamping.

In Fig. 7 is illustrated means for introducing a short bar or partition. In its upper end isahole, provided with suitable screw-threads or equivalent, to receive a rod 5, correspond- IOO ingly threaded. This rod, being connected with the bar, can be used to lower it in the hole in the rock either before or after the powder and -fuse have been introduced. A washer can be used to hold the partition centrally and support the tamping, or paper may be rammed in for this purpose. Before tamping, the rod is unscrewed and removed, and the top of the partition then receives the main force of the blows employed in this part of the operation. IVhen the explosive, the fuse, or equivalent igniter, and the partition have been properly placed in the bore, the charge will be divided into two or more portions by the bar 1, the edges of said bar bein g arranged in the planes of desired fracture. Thereupon the charge is ignited, and I have discovered that its explosive force is so directed and expended by the above-described means as to break the rock in planes, passing through the edges of the dividing-bar about midway between the adjoining faces of the bar. The bar being acted upon simultaneously by the separate divisions of the exploding material, causes the force of explosion to react in opposite directions or in directions determined by the faces of the bar. The novelty and utility of the invention, however, does not depend upon the above explanation or theory, as the suggested result can be attained by proceeding as specified, whatever theory may be entertained, and thereby the labor and vexpense of grooving the bore along the desired line of fracture heretofore incurred can be obvia'ted; noris it essential that the edges of the bar be vertically arranged, as similar effects can be produced by arranging them horizontally or in planes between the vertical and the horizontal, or even in curved lines.

It will be understood that neither the use of the dirt packing at the bottom of the bore, nor the particular time or order of inserting the explosive, nor the special means of introducing the dividing-bar, nor the particular form or-number of such bars, nor the inode of tampingare essential to the main effect of my improvement. According to the preferred method, however, a dirt packing sufficient to cover the foot of the bar is first introduced and the bar is then inserted and forced into the dirt, whereupon the explosive material is charged and the fuse or other ignitor inserted in manner to insure ignition of the whole charge, and, finally, suitable material is tamped about and upon the top of the bar and the charge exploded.

In Fig. S I have shown the simplest means for carrying out my improved method, which consists in a bar entered in the blast-hole, and adapted to produce with the wall of said hole anzelongated opening,which may be approximately elliptical or of equivalent form in cross-section, the purpose of this being to direct the main force of expansion at right angles to the longest diameter of the bore or hole.

Having thus described my invention, what I desire to secure by Let-ters Patent isl. The improvement in the art of blasting,

which consists in providing a cylindrical bore or charging-hole and in dividing the charge lengthwise of the bore by a partition, substantially as described.

2. The improvement in the art of' blasting, which consists in providing a cylindrical bore or charging-hole and in dividing the charge lengthwise of' the bore by a partition, and placing a packing of dirt or similar material about the foot of the partition, substantially as described.

'3. The improvement in the art of blasting, which consists in providing a cylindrical bore or charge hole and dividing the charge lengthwise of said blast hole by a bar or partition having angular or approxi mately angular edges contiguous to the face of Ithe bore and then exploding the charge, substantially as described.

4. The improvement in blasting,which consists in forming a cylindrical hole in the material to be blasted, and then partially filling said hole laterally with a bar disposed lengthwise of the cylindrical hole and producing a charging space or receptacle having an approximately oblong form, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JOHN A. KURTZ.

Vitnesses:

J oHN H. CRATTY, WILLIAM RAPF.