US2999459A

US2999459A - Apparatus for handling explosive cartridges

Info

Publication number: US2999459A
Application number: US452125A
Authority: US
Inventors: Lester P Barlow
Original assignee: Atlas Powder Co
Current assignee: Atlas Powder Co
Priority date: 1954-08-25
Filing date: 1954-08-25
Publication date: 1961-09-12
Anticipated expiration: 1978-09-12

Description

p 1961 P. BARLOW APPARATUS FOR HANDLING EXPLOSIVE CARTRIDGES 2 Sheets-Sheet 1 Filed Aug. 25 1954 Se t. 12, 1961 P. BARLOW 2,999,459

APPARATUS FOR HANDLING EXPLOSIVE CARTRIDGES Filed Aug. 25, 1954 2 Sheets-Sheet 2 2,999,459 APPARATUS FOR HANDLING EXPLOSIVE CAR n-GES Lester I. Barlow, Stamford, Conn, assignor to Atlas Powder Company, Wilmington, DeL, a corporation of Delaware Filed Aug. 25, 1954, Ser- No. 452,125

6 Claims. (Cl. 102-24) This invention relates to the apparatus for and method of loading a blast hole with cartridges of a liquid-oxygen carbon explosive, and more particularly the equipment and construction of the apparatus that is required for the safe handling of the cartridges after charging the cartridges with liquid-oxygen and in lowering them into position in the hole for the blast.

Liquid-oxygen carbon explosive has been long known, but used to a very limited extent because of the extreme hazard usually accompanying its use, which is due to the fact that the usual liquid-oxygen carbon explosive is very easily detonated by, for example, a spark, in handling a bag of liquid-oxygen carbon explosive. 'In my copending application Serial No. 351,035, filed April 24, v1953, now abandoned, I have explained a way in which the liquidoxygen carbon explosive can be made safe .from this ordinary hazard. However, there is the usual difficulty of handling the liquid-oxygen involved and the time element that must be considered when workingfwith this type of explosive. It has been the practice in'working with liquid-oxygen carbon explosive to merely bag the carbon in a fabric bag and soak it in a liquid-oxygen bath until the carbon is saturated and then by crudehandling equipment, the bags are stacked in the holes one by one,

one on top of another, until a suflicient number of bags have been placed in the hole for the blast. With the lowering of each bag into the hole, there is danger'that the bag may contact the side wall of the hole and if a spark is struck, the explosive will go ofi prematurely. Characteristics of the liquid-oxygen carbon explosives in the past have been so erratic that it is not known in many cases what causes them to detonate prematurely, but accidents have happened in their use due to faulty handling as well as to the inherent instability of the conventional liquid-oxygen carbon explosive.

By this invention, a liquid-oxygen carbon explosive cartridge is provided that lends itself to easy'handling both from the safety point of View of the people loading the hole and from the time element that is always involved in the use of liquid-oxygen. The hole must beloadedquiokly so that the oxygen will not exap'orate.

It is an object of this invention to provide a cartridge- 2,999,45 Patented Sept. 12, 1961 FIGURE 1 is a view of a loading rig showing the man ner in which the cartridges are assembled for ilowerinl into a blast hole; I

FIGURE 2 is an enlarged view showing the lower end of the unit and a section through one of the cartridges; 1.

FIGURE 3 is a cable support frame used intermediate the cartridges;

FIGURE 4 is a plan view of a perforated plate in the bottom of each cartridge;

FIGURE 5 is a plan view of a snap ring.

FIGURE 6 is a perspective view of a holding clamp used for lowering the assembly of cartridges into the hole; and

FIGURE 7 is a sectional view of the cartridge soaking vat. v. i

In the drawings, FIGURE .1 shows a blasthole 1 drilled in the earth for the purpose of receiving a blast-charge. A rig J2is assembled over hole 1 tofacilitate the assembly of cartridges Sinto a blast unit. Cartridges 3 will be described in further detail in connection with FIGURE 2.

Rig 2 consists of a frame comprising members 4, .5 and 6. Bearings 7 on frame 4 held in place by brackets 8,

support a shaft 9 on which are mounted reels 10 of cable 11 that extend down into the blast hole. cured to a base member or wood block nose 12 hyan eyelet or stap1e'13. Cables 11 form the loadliftingmembers for the weight of the assembly of cartridges and a lateral guide for the assembly of cartridges in one threetion. Other cables ll, extending from other reels 1 0, which are similar to reels Ill, are secured to block 12th. fastening eyelets 13' to afford lateral stability in the other direction by being located approximately ninety degrees from cables 11.

; cartridge 3 is then'placed inside wireframe .17 and foot or container for carbon which when soaked in liquid oxygen becomes a liquid-oxygen carbon "explosive cartridge. p p

It is another object of this invention'toprovide aliqui'd oxygen carbon explosive cartridge that 'nray be :easily handled from the oxygen soaking vat to the rig that lowers it into the hole.

A further object of this invention is the provision of a rig for handling the liquid-oxygen carbon explosive 'cartridge and for assembling the cartridges into an explosive unit for lowering it into the hole with the maximum safety and the minimum consumption of time.

It is a further object to provide a cartridge that lends itself to be assembled with similar cartridges to cause carbon-to-carbon contact to insure the propagation of the When it is desired to load a hole, the rig is assembled over the hole and cables 11 and 11' attached to block 12. The first cartridge 3 is placed on block 12 and loweredt'o a position slightly below the surface of the earth by permittingreels 10 to'pay out cables 11 'upon the .release of brake 1-4 by foot pedal 15. It will be noted that .foot pedal 15'and rod 16 actuate not only brake 14 for cables 1.1, but brake 14 for cables 11'. A wire cable support frame 17 shown in perspective in FIGURE 3 is .then;placed inside the top of the first cartridge. -Frame 17 is eta very light wire that is merely positioned to extend out of the top of .the cartridge to engage cables -11 and 11 to insure some degree of lateral stability of the unit; Next pedal 15 is released so that the assembly of twocartridges is lowered to a position slightly below the surface'ofthe earth and the operation repeated until a sutl'icient number of :units of cartridges have been assembled for the particular'blast.

In on: of the-cartridges in the assembly {and .it may he any one, the .topis punctured and a primacord inserted as detonation of the explosion from one cartridge to the a .fuse'in the first cartridge or any one :of the cartridges of the unit. Such .a primacord is shown at ldinserted in the first cartridge and extends outbetween the space'between first and second cartridges and along the assembly up through and out the top of thehole. It should be noted that the space between the cartridges is due to the tapered shaped}? the cartridge. This space also permits the-escape of oxygen as it evaporates from eachcartridge.

When the proper number-of unitshave beenassernbled in the hole and the last one is aboutstq belowered as havethe preceding ones, a holding clamp 19 is brought into firm contact with the top of the last cartridge and clamped onto cable llbyiany suitable clamp means, such as "20, which can be quickly assembled and disassembled therefrom. Cables 11 are depended upon for the prime load-bearing function of the weight of the assembly of cartridges. Cables 11' are cut and merely wrapped around member 19 and secured thereto to afford lateral Cable 11 .is se- 7 l 3 stability for the assembly of units. A hook 21 engages an eyelet 22 in member 19 and by means of cable 23 wound on reel 24, the cartridges are lowered into the bottom of the hole as shown in the dotted line position in FIGURE 1. Cables 11 are out after hook 21 engages eyelet 22 in member 19 and thereafter supports the load of the assembly. Line 23 is then jerked to disengage hook 21 from eyelet 22. Primacord 18 has been payed out as the unit was lowered into the hole.

Cable 23 and hook 21 are wound back onto reel 24 and the whole rig removed from the location of the hole which, after stemming, is now ready for detention.

It should be pointed out that two advantages are provided by the assembly of units previously described. One is that a wooden block 12 is employed as a nose on the assembly of units which is incapable of striking a spark as the unit is lowered into the hole, and the second is that non-ferrous metals are used throughout, particularly in the construction of the container, to further avoid this hazard.

The cartridge 3 shown in more detail in FIGURE 2 consists of a non-ferrous metal or aluminum shell 25 which is slightly tapered from the top to the bottom. The bottom end is formed with a rolled edge 25a to form a support for a perforated plate 26 shown in plan view in FIGURE 4. Plate 26 has relatively large perforations. A fabric member, either cloth or paper, is shown at 27 covering plate 26 to prevent the granules 'of carbon from spilling out through the relatively large perforations in plate 26. The mass of carbon particles 28 is loaded into shell 25 on plate 26 until shell 25 is filled up to approximately groove 29 near the top of the shell. At this point the top is closed by another fabric member 30, either paper or cloth, which is retained in groove 29 by snap ring 31 shown in detail in FIGURE 5. The function of this snap ring is to loosely retain member 30 closing the top of the cartridge. Member 17 which engages

cables

11 and 11 fits down tightly onto member 30, since the cartridge 3 above presses it firmly down onto the surface of the carbon in the lower cartridge. It must be remembered that carbon 28 in the cartridge is saturated with liquid-oxygen which is continuously evaporating. This evaporation of the liquid-oxygen causes the gaseous oxygen to work its way up through the carbon in cartridge 3, and as it does so, it causes diaphragm or retaining fabric member 36 to bow upwardly in contact with the bottom of the next cartridge above in the spaces between the ribs of member 17. The evaporation of the oxygen, more or less rapidly, tends to carry particles of carbon upwardly through the container until they are trapped by member 30. In effect, this causes practically carbon-to-carbon contact between the successive cartridges, because some of the carbon will work through the interstices of members or

diaphragms

27 and 30 and through the perforations in plate 26 to cause a continuous carbon-to-carbon contact between cartridges and, in elfect, the continuous column of carbon throughout the assembled unit. This is impor-- tant from the point of view of propagation of the detonation throughout the unit.

FIGURE 7 shows a soaking bath for the prepared cartridges of carbon. As has been described above, the cartridges 3 consist of a non-ferrous metallic sleeve 25 closed at the bottom with

members

26 and 27 filled with carbon 28 and closed at the top with member 30 held in place by a retaining ring 31. The metal for this cartridge is preferably aluminum and is very lightweight and easily formed. It can be pre-formed and shipped or formed in place, that is on location at the point of use, from prepared flat sheets. It is significant that this cartridge, whether prepared on location or prepared at a plant and shipped to the location, consists of nothing but carbon granules and without being saturated .with liquidoxygen is absolutely safe from detonation. At the location of the blast, a vat 35 having a cover 36 will be'sub stantially filled with liquid-oxygen 37. Cartridges 3 loaded with carbon will then be placed in the vat by any suitable handling tongs, such as 38. Asbestos gloves 39 are usually worn to protect the hands of the operator from the extreme cold of the liquid-oxygen. Cartridges 3 are placed in the vat close enough together so that they will not tip over. At the outset, they will tend to float, but they will be held substantially submerged in the liquidoxygen by cover 36. As the carbon absorbs the liquidoxygen and is cooled by the action of the liquid-oxygen, the cartridges 3 will sink as shown by the left-hand cartridge 3 in FIGURE 7 and rest on the bottom until time to remove them from the vat and be loaded into the assembly to be lowered into the blast hole. When the cartridges sink to the bottom of the vat, it is also an indication that they have absorbed enough of the liquidoxygen so that they are ready for use. The cartridges can then be quickly removed from the vat by tongs 38 and assembled as has been described above in connection with FIGURE 1, for lowering into the hole as a unit.

It is to be understood that certain changes, alterations, modifications, substitutions can be made in the abovedescribed invention without departing from the spirit and scope of the appended claims.

I claim:

1. A blasting unit comprising a plurality of cartridges of carbonaceous material which are to be charged with liquid-oxygen, said cartridges being assembled into endto-end vertical relationship with similar cartridges, a rigid base means on which the lowermost of said cartridges rests, cable holding means over the uppermost of said cartridges, cable means extending longitudinally of said plurality of cartridges for longitudinal stability and attached to said base means and said holding means, each of said cartridges comprising a generally frusto-conical sleeve member, means adjacent the bottom of said sleeve member retaining an apertured plate member, a foraminous diaphragm covering said apertured plate member to prevent the passage of carbon therethrough, a second foraminous diaphragm adjacent the top of said cartridge, means to retain said diaphragm spaced inwardly from the top of said cartridge to retain the carbon in said cartridge, said top diaphragm member being flexible and loosely retained so that it will bow upwardly as the oxygen evaporates to cause contact with an adjacent cartridge, and cable engaging means positioned intermediate adjacent cartridges to secure said cartridges against lateral displacement. Y

2. A cartridge containing carbon particles and adapt d to be charged with liquid-oxygen and assembled into endto-end relationship with similar cartridges as a blast unit, comprising a rigid, impervious generally frusto-conical,

non-ferrous sleeve member, the external dimensions of the smaller end of the said sleeve member being sufiiciently smaller than the internal dimensions of the larger end of said sleeve member that the difierence in area between the external area of said smaller end and the internal area of said larger end is sufiicient to permit a free flow of gases, at first fabric diaphragm extending across and closing the smaller end of said sleeve member to retain the carbon charge in said cartridge, an apertured plate member positioned across the smaller end of said sleeve member inside of and adjacent to said fabric diaphragm, a second fabric diaphragm positioned inwardly from the larger end of said sleeve member and extending across the inside of said sleeve member to form a closed cartridge unit, said second fabric diaphragm memher being flexible and sufi-lciently loose that when said cartridge is loaded with liquid oxygen and positioned with its large end directed upwardly said second fabric diaphragm member will bow upward a distance equal to that between small endof said cartridge and said first fabric diaphragm as the oxygen evaporates from said cartridge, said first and second diaphragm members being sufficien-tly porous to permit some of said carbon to work therethrough.

3. An explosive charge assembly comprising a plurality of liquid oxygen-charged, carbon-filled cartridges stacked one on top of the one below to form a substantially continuous vertical column of liquid oxygencarbon explosive the lowermost of said cartridges resting on a rigid base member, a plurality of spaced cable means secured to said base member and extending vertically along the sides of said stacked cartridges, rigid cable support frame positioned between at least some of said cartridges and slidably attached to said cable means to maintain said cable means in a spaced relation and to secure said cartridges within the periphery dormed by said cable means, and means to clamp said cable means at the top of the uppermost of said cartridges to hold said plurality of cartridges in an assembly.

4. An explosive charge assembly as defined in claim 3 wherein the said base member is composed of a nonferrous material.

5. An explosive charge assembly as defined in claim 3 wherein the said base member is shaped to guide the assembly down a blast hole.

6. An explosive charge assembly comprising a plurality of liquid oxygen-charged carbon-filled cartridges stacked one on top of the one below to form a substantially continuous vertical column of liquid oxygen-carbon explosive, the lowermost of said cartridges resting on a rigid base member, a plurality of spaced cable means secured to said base member and extending vertically along the sides of said stacked cartridges, a plurality of cable support frames slidably attached to said cable means to maintain said cable means in a spaced relation, said support frames being positioned between said cartridges, means to clamp said cable means at the top of the uppermost of said cartridges to hold said plurality of cartridges in an assembly.

References Cited in the file of this patent I UNITED STATES PATENTS 29,390 Lewis July 31, 1860 577,732 Egestorff Feb. 23, 1897 1,239,247 Allison Sept. 4, 1917 1,540,726 Moore June 2, 1925 1,544,247 Lewis u... June 30, 1925 1,763,407 Niesen June 10, 1930 1,767,182 Lisse June 24, 1930 1,863,921 McCloud June 21, 1932 2,021,632 Mathey et a1 Nov. 19, 1935 2,216,067 7 Clark Sept. 24, 1940 2,222,882 Shames Nov. 26, 1940 2,238,939 Lewis et a1 Apr. 22, 1941 2,295,854 Lindsley Sept. 15, 1942 2,317,354 Bennett Apr. 27, 1943. 2,472,997 Williams June 14, 1949 2,590,671 Baker Mar. 25, 1952 2,594,780 Lewis Apr. 29, 1952 2,685,251 Davis et a1. Aug. 3, 1954 2,704,515 Barlow Mar. 22, 1955 FOREIGN PATENTS 48,922 Sweden Mar. 16, 1918 148,538 Great'Britain Oct. 10, 1921 471,056 Great Britain Aug. 20, 1937 OTHER REFERENCES 1920; Technical Paper 243, Dept. of Interior (Bureau of Mines), pages 21, 38 and 42 relied on.