US3125925A - X xartridges - Google Patents

Description

March 24, 1964 s. H. LJUNGBERG 3,125,925

APPARATUS FOR LOADING BOREHOLES IN BED-ROCK WITH CARTRIDGES OF EXPLOSIVE Filed March 20, 1961 2 Sheets-Sheet 1 Fig.1

' INYENTQR STEN HERMAN LJUNGBERG BY We, 2' air ATTORNEY March 24, 1964 s. H. LJUNGBERG 3,125,925 APPARATUS FOR LOADING BORE-HOLES IN BED-ROCK WITH CARTRIDGES OF EXPLOSIVE Filed March 20, 1961 2 Sheets-Sheet 2 INVENTOR STEN HERMAN LJUNGBERG BY %wama4z 2 7 ATTORNEY 3,125 925 APPARATUS FOR LOADIDIG'BORE-HOLES IN BED- ROCK WITH CARTRIDGES F EXPLOSIVE Sten Herman Ljungberg, Stockholm, Sweden, assignor to Nitr'oglycerin Aktiebolaget, Gyttorp, Sweden, :1 corporation of Sweden Filed Mar. 20, 1961, Ser. No. 96,821 Claims priority, application Sweden Mar. 22, 1960 5 Claims. (Cl. 8620) This invention relates to an apparatus for loading boreholes with explosive.

More particularly this invention relates to an apparatus for loading bore-holes in bed-rock with cartridges of explosive constituted by a plastic mass or a powder.

The apparatus comprises a tube insertable into the bore-hole and connected at one end with a breech-piece or magazine into which the cartridges are fed and by means of a pressure fluid advanced along the tube and discharged through the remote end located in the bore-hole of the tube. Apparatus of this kind are described in the specification of the Patent No. 2,824,483 granted February 25, 1958 to C. H. Johansson and in the co-pending patent application Serial No. 711,417, now Patent 3,040,650, filed January 27, 1958 by C. H. Johansson and S. H. Ljungberg, to which specifications reference is made for a more detailed description of the apparatus in consideration.

One main object of the invention is to provide a loading apparatus of the type set forth in which the cartridges one behind the other not only are introduced into the breech-piece, but also advanced through, and discharged from the tube by means of the pressure fluid.

A further object of the invention is to provide a loading apparatus of the type in consideration, by which a quick loading of the bore-holes is rendered possible by making the introduction of the cartridges continuously instead of intermittently as with earlier loading apparatus.

A still further object of the invention is to provide a loading apparatus of the type set forth by which due to simultaneous presence of a few cartridges only in the tube, the loading can be eflected with more uniform speed than hitherto.

Still another object of the invention is to provide an apparatus for loading bore-holes with cartridges of explosive constituted by a plastic mass or a powder, and of the structure set forth, in which the danger of cartridges becoming jammed in the tube is practically eliminated.

Further objects and advantages of the invention will become apparent from the following description considered in connection with the accompanying drawings which form part of this specification, and of which:

FIGS. 1 and 2 are partial longitudinal sections of two embodiments of loading apparatus constructed according to the invention.

Referring to FIG. 1 of the drawing, reference numeral denotes a loading tube which may be of metal or plastic or similar material and which preferably is flexible as a hose. Said tube is intended to be introduced into bore-holes formed in bedrock or the like for the purpose of filling the holes with explosive. The explosive is supplied encased in cartridges having an external diameter less than the interior diameter of the tube.

Attached to the end of the tube projecting out of the bore-hole is a breech-piece or magazine generally designated by 12 and formed with an opening 14 for introducing cartridges either manually or by means of a device operating automatically. The cartridges pass initially through a valve chamber 16 and a tube 18 connected thereto which tube suitably has a length slightly exceeding that of the individual cartridge. The tube 18 has an United States Patent 0 ice inner diameter which is slightly larger than the diameter of the cartridge. A flap or damper 20 is mounted in the valve chamber 16 turnable about a pivot 22. This valve flap 2i? is represented in two positions, one of which is illustrated by full lines where the flap fits with an annular seat 24 of rubber or some other soft material and keeps the opening 114 closed, whereas in the other position indicated by dash and dotted lines the flap is turned down and leaves free passage for the cartridges to enter the chamber 16. Disposed between the two tubes 10 and 13 is a second valve chamber 26, within which a flap or damper 28 is turnable about a pivot 30. The flap 28 is shown in one position indicated by dash and dotted lines, where it fits with an annular seat 32 of rubber or similar soft material and interrupts the connection between the tube 18 and the chamber 26. The flap 28 is also illustrated by full lines in a turned-down position where it leaves open the passage for advance of the cartridges through the chamber 26 and further into the tube 10.

Opening into the chamber 16 is a pipe or conduit 34 and into the chamber 26 a pipe or conduit 36, which pipes are connectable through a control or main valve generally denoted by 38 and a pipe or conduit 45) with a source of pressure fluid constituted by a liquid (water) or a gas. In the following description the fluid is assumed to be constituted by compressed air. Disposed in the pipe 34 is a high-speed relief valve 41 of known type. The inlet pipe 49 for the pressure fluid is controlled by a pressure reducing valve 42 and a shut-oi]? valve 44. The main valve 38 has for its object to guide the compressed air alternately to one or the other of the two chambers 16 and 26, respectively, and is for this purpose provided with a slide member 46 axially displaceable within a valve box 43. The slide member :6 has two flanges 5t 52, which is the position shown in FIG. 1 interconnect the pipes 4t and 34, so as to allow compressed air to flow through said pipes into the valve chamber 16. An outlet 53 opening into the free atmosphere is sealed from the pipes 44 and 34 by the flange 50. Further, the pipe 36 is cut 011? from air supply through the pipe 40 by the flange 52. The slide member 46 has moreover two end flanges 54, as which alternately are exposed to pressure through intermediation of an auxiliary valve generally designated by 58 and encasing a slide member 60 axially displaceable therein. From the upper space 61 of the main valve 38 a pipe 62 extends to the auxiliary valve 58. Another pipe 64 connects the space 66 below the flange 56 in the main valve with the auxiliary valve 58, into the box 68 of which said two pipes open in spaced relationship from one another. A branch pipe 70 extends from the supply pipe 46 for the compressed air to the auxiliary valve 58, the slide member 6d of which is formed with two inner flanges 72 and 74 controlling the supply of pressure fluid to the two end spaces of the main valve 38. According to the positions illustrated in FIG. 1 the pipes 70 and 62 are in connection with one another for which reason the main valve 38 is fed with compressed air into that space 61 where the end flange 54 of the slide member 46 is located. At the same time the space '76 outside the end flange 78 of the slide member 66 in the auxiliary valve is in communication with the pipe '70 through a channel 80 formed in the valve box. On the opposite side of the auxiliary valve, however, the space 82 outside the end flange 84 of the slide member is without pressure due to the fact that it is in communication with the free atmosphere through a channel 86 and an opening 88 in the valve box 68. In the same manner the pipe 64 and therethrough the space 66 below the flange 56 in the main valve 38 are without pressure. An exhaust opening 90 corresponding Q) to the opening 88 is formed in the auxiliary valve 53 for discharge into the free atmosphere of the upper channel system formed in said valve.

The apparatus operates in the following manner.

The slide member 46 in the main valve 33 is assumed during its reciprocating movement to have arrived at or adjacent its upper reversing position according to the figure in consideration. A communication has thus been established between the inlet pipe 40 and the pipe 34 so that (assuming the valves 42 and 44 to be open) compressed air enters the chamber 16 of the breech-piece 12. The incoming air stream has turned the flap 20 upwards into the position represented by full lines where it is retained by the overpressure of the air. The pipe 36 is cut off, for which reason the flap 28 takes its open position indicated by full lines. A cartridge of explosive which already is present in the tube 18, is advanced by the air stream coming from the pipe 34 through the chamber 26 into the tube 16.

Also the slide member 60 of the auxiliary valve 58 is in its upper end position. A communication has thus been established from the pressure source through the branch pipe 7 0, the valve 58 and the pipe 62 to the space 61 above the slide member 46. This results in that said slide member at a predetermined moment is caused to move downwards.

Following the reversal of the slide member 46 the flange 66 will pass past the mouth of the pipe 34 so that this pipe is brought into communication with the outlet 53. Hereby, a reduction of pressure is caused in the pipe with reduction in turn actuates the valve 41 in known manner so as immediately to open into the free atmosphere, the chamber 16 and the tube 18 being relieved hereby. The flap 2t) falls down into its inoperative position. In addition the communication in the valve 38 between the pipes 49 and 36 is established. The incoming compressed air turns the flap 28 into the closing position indicated in FIG. 1 by the dash and dotted lines. The cartridge introduced into the tube is new advanced further towards and discharged through the remote open end of the tube located in the bore-hole. Adjacent said end, knife members which cut up the envelopes of the cartridges before the explosive is packed in the bore-hole, may be arranged in accordance with the disclosure of the patent specification mentioned hereinbefore.

In the meantime a fresh cartridge is fed in through the opening 14 and is allowed to fall down into the initial poistion in the tube 18.

During the period of the downward movement of the slide member 46 a pressure is built up through the channel fltl in the space '76 of the auxiliary valve 58 above the end flange 7S and this pressure finally attains a value high enough to cause the slide member 66 to reverse and thereby to break the supply of compressed air to the pipe 62 and instead to open a connection through the pipe 70 to the pipe 64 and therewith to the space 66 in the valve 38 located below the end flange 56. Simultaneously, the communication with the outlet 36 is shut off by the flange '74. Following the reversal of the slide member 66 the pipe 62 and the channel 86 are instead brought into communication with the surrounding free atmosphere through the opening 96. The supply of pressure fluid to the pipe 64 results in that the slide member 46 in the main valve 38 moves back into the position shown in the figure, where compressed air is again guided into the pipe 34 and the chamber 16. Simultaneously, the pressure in the space 82 outside the flange 84 of the auxiliary valve is increased successively and finally reaches a value high enough to cause the slide member 66 to revert to the position illustrated in FIG. 1. In this manner an alternate supply of compressed air is brought about through the two pipes 34, 36. The frequency can be varied by increase or reduction of the different flow paths, especially by adjustment of the flow areas constituted by the cross-sections of the outlet openings 88, 90. In these channels a throttling effect is thus exerted on the air, which throttling elfect may be made variable, if desired.

Since the flaps 20 and 28, respectively, are actuated with a relatively feeble force by the air flows entering through the pipes 34 and 36, respectively, and moreover the valve seats 24, 32 are constitutedby a soft material, cartridges of explosive which happen to be in the flap opening when the flap closes, cannot be damaged and need not even be deformed. Therefore any risk of a noxious action on the cartridges is precluded.

The embodiment illustrated in FIG. 2 differs from the preceding one mainly by the feature that the auxiliary valve receives its impulses through preferably mechanical actuation by the cartridges when these are introduced into the breech-piece 12. The auxiliary valve may be constituted by a simple valve body 92 formed to co-operate with a seat 94 in a chamber 96 into which a pipe 98 opens. The pipe 98 is connected to the pipe 40, suitably at a place ahead of the pressure reduction valve 42.

The pipe 62 in this embodiment connects the upper space 61 of the valve 38 with the chamber 96. The chamber 61 is through a narrow throttle hole 99 in permanent communication with the free atmosphere.

A feeler member, preferably formed as a lever arm 160, is journalled on a pivot 102 mounted in a recess 104 adjacent the tube 18. One end of the arm is connected through intermediation of a pivoted spindle 106 with the valve body 92. The spindle 106 passes with a sliding fit through the common wall of the chamber 96 and the recess 164. A screw spring 108 acts on the other end of the arm 1% so that the valve body 92 normally is kept in fitting contact with the valve seat 94. The movement of the valvebody toward the closing position may be damped by weaker screw spring 110. The arm 100 projects with its lower part as represented in FIG. 2, into the tube 18 so that it will be hit by the cartridges of explosive passing through said tube. Hereby the arm is turned counterclockwise so that the valve body 92 leaves its seat 94 and compressed air streams through the pipe 98, the chamber 96 and the pipe 62 to the upper space 61 of the main valve 38 resulting in that the slide member 46 is conveyed downwards against the action of a screw spring 112 mounted in the chamber 66.

When the slide member 46 occupies its upper end position in the valve 38 according to FIG. 2, pressure fluid flows through the pipes 40 and 36 to the lower chamber 26. The valve flap 28 is kept closed by the overpressure prevailing in the chamber 26. One or several cartridges of explosive which happens to be positioned in the tube 16 are advanced by the pressure fluid to and out of the remote free end of the tube located in the bore-hole. At the same time the valve body 92 is retained by the spring 168 in closing position. In the chamber 96, the pipe 62 and the upper space 61 of the valve 38 atmospheric pressure prevails due to the communication with the free surrounding atmosphere through the narrow hole 99. The chamber 16is in communication with the free atmosphere through the pipe 34- and the outlet 53 in the valve 38. Therefore, the valve flap 20 has turned down into its position.

If now a fresh cartridge of explosive is introduced into the chamber 16 and continues to advance into the tube 18, it will actuate the arm 106 so as to cause said arm to reset the valve body 92 into opening position. Pressure fluid flows from the pipe 98 past the valve body through the pipe 62 into the chamber 61 of the valve 38. The slide member 46 of this latter is pressed downwards to a lower position while compressing the spring 112. In this position of the slide member 46 the supply of pressure fluid through the pipe 36 is interrupted and instead pressure fluid caused to flow from the pipe 40 through the pipe 34 into the upper chamber .16. The valve flap 20 closes and the increased pressure built up in the chamber 16 advances the introduced cartridge to the lower chamber 26 and into the tube 10. The lever arm 100 is released again so as to cause the valve body 92 to close. The pressure fluid present in the space 61 escapes through the narrow hole 99 and the spring 112 returns the slide member 46 to its upper end position. Thereby the communication between the source of pressure fluid and the pipe 36 is re-established. The flap 28 which was opened by the cartridge or the overpressure acting from above is closed again. The cycle is repeated every time a fresh cartridge is introduced into the breech-piece.

The spaces 61, 66 or/and 76, 82, respectively, outside the end flanges of the slide members 46 or/and 60, re spectively can be varied with respect to their volume by means of an adjustable piston or the like, whereby the period of time can be varied, within which the pressure in the space reaches the value required for causing reversal of the slide member. In this manner also the number of cycles for the oscillating movements of the slide members may be adjusted to various values with regard to the nature of the exposives.

In the embodiment shown in FIG. 2 it is possible to supply a predetermined quantity of pressure fluid continuously to the lower chamber 26. In this chamber the pressure will always be lower than in the upper chamber 16 when the valve flap 20 of this latter is closed and pressure fluid enters through the pipe 34. For this reason there does not exist any risk for the flap 28 to open so as to allow a fresh cartridge to pass into and through the chamber 26. It is even conceivable to connect the pipe 36 with the pipe 40 so as to by-pass the valve 38, the supply of compressed air to the chamber 26 then continuing without any even partial interruption. In such a case the valve 38 has for its sole purpose to bring about an oscillating supply of pressure fluid to the upper chamber 16.

While several more or less specific embodiments of the invention have been shown and described, it is to be understood that this is for the purpose of illustration only, and that the invention is not to be limited thereby, but its scope is to be determined by the appended claims.

What I claim is:

1. Apparatus for loading a bore-hole in bed-rock with cartridges of explosive comprising a tube received within said bore-hole, a breech-piece connected to one end of said tube, said breech-piece having a first chamber and a second chamber disposed substantially in axial alignment, conduits connecting each of said chambers to a source of fluid pressure, a feed opening connected to said first chamber, a first valve member interposed between said first chamber and said feed opening, a second valve member interposed between said first and second chambers, a reversing valve interposed in said conduits between said chambers and the source of fluid pressure, said valve including a casing, a slide member reciprocably mounted in said casing, and means for axially moving said slide member to create alternating communication between the source of fluid pressure and said conduits to cause said valve members to alternately close by force of said fluid pressure and open by gravity or by a cartridge passing through the valve opening to sluice the cartridges of explosive through said chambers and advance the cartridges to the remote end of the tube in the bore-hole.

2. The structure of claim 1 including a tubular elongation on said first chamber of a length at least equalling the length of one cartridge.

3. The structure of claim 1 in which said valve members include valve seats, and flap-like elements selectively movable from an open position to a closed position against said valve seats by fluid pressure.

4. The structure of claim 1 in which said first chamber is alternately subjected to fluid under pressure and exhausted to atmospheric pressure and said second chamber always contains fluid under pressure.

5. The structure of claim 1 in which the fluid pressure in both of said chambers is utilized to advance said cartridges.

References Cited in the file of this patent UNITED STATES PATENTS 699,405 Newhouse May 6, 1902 1,336,674 Brawn Apr. 13, 1920 1,946,780 Costello Feb. 13, 1934 2,688,314 Holm et al. Sept. 7, 1954 2,956,840 Mead Oct. 18, 1960 3,040,615 Johansson et al. June 26, 1962 FOREIGN PATENTS 834,052 Great Britain May 4, 1960

Claims (1)

1. APPARATUS FOR LOADING A BORE-HOLE IN BED-ROCK WITH CARTRIDGES OF EXPLOSIVE COMPRISING A TUBE RECEIVED WITHIN SAID BORE-HOLE, A BREECH-PIECE CONNECTED TO ONE END OF SAID TUBE, SAID BREECH-PIECE HAVING A FIRST CHAMBER AND A SECOND CHAMBER DISPOSED SUBSTANTIALLY IN AXIAL ALIGNMENT, CONDUITS CONNECTING EACH OF SAID CHAMBERS TO A SOURCE OF FLUID PRESSURE, A FEED OPENING CONNECTED TO SAID FIRST CHAMBER, A FIRST VALVE MEMBER INTERPOSED BETWEEN SAID FIRST CHAMBER AND SAID FEED OPENING, A SECOND VALVE MEMBER INTERPOSED BETWEEN SAID FIRST AND SECOND CHAMBERS, A REVERSING VALVE INTERPOSED IN SAID CONDUITS BETWEEN SAID CHAMBERS AND THE SOURCE OF FLUID PRESSURE, SAID VALVE INCLUDING A CASING, A SLIDE MEMBER RECIPROCABLY MOUNTED

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