US2720168A - Material breaking cartridge - Google Patents

Description

INVENTOR Jam Cfisson/ R R l M A.

J. C. HESSON vm EWQM Filed Jan. 18, 1952 MATERIAL BREAKING CARTRIDGE Oct. 11, 1955 A RNEY BYfYMA United States Patent MATERIAL BREAKING CARGE James C. Hesson, Riverdale, Ill., assignor to Cardox Corporation, Chicago, 111., a corporation of Illinois Application January 18, 1952, Serial No. 267,038 6 Claims. (Cl. 102-25) This invention relates to new and useful improvements in material breaking cartridges of the type employing a high pressure gas as the work performing medium, the release of the gas being effected by a quick acting, full opening valve which may be controlled from a point remote to the cartridge.

Cartridges employing a highly compressed charge of gas for breaking down coal in mines, and for other similar operations, are well-known and have been widely used in recent years. Such cartridges usually are charged with compressed air after they are positioned for operation with the air being obtained from a receiver that is formed by a suitable length of tubing which is connected to a remotely located high capacity compressor. It readily will be apparent that for different installations and/ or operating conditions the desired working pressure of the air charge may vary through a substantial range of values. The pressure at which the cartridge will be discharged each time it is operated, therefore, will be at the desired value only if the amount of compressed air delivered to the cartridge is properly controlled. It, also, is of primary importance that the compressed air charge will be quickly and completely released during each operation of the cartridge and that the cartridge will be easily and automatically reconditioned for a subsequent operation each time it is used.

The primary object of this invention is to provide a compressed air, material breaking cartridge having a charge release mechanism which is located entirely in the discharge end of the cartridge and which will be caused to operate, after the cartridge is properly charged, by withdrawing some of the compressed air from the cartridge.

A further important object of the invention is to provide a compressed gas, material breaking cartridge of the aforementioned type having a charge release mechanism located entirely in the discharge end of the cartridge and including a plurality of valves which are sequentially operated by the differential forces of the fluid pressure acting thereon.

Another important object of the invention is to provide a compressed air, material breaking cartridge having a quick opening charge release mechanism located entirely in the discharge end of the cartridge and including a plurality of sequentially operating valves, the actuation of which is effected by controlling air pressure that is acting on one of the valves.

A still further object of the invention is to provide a compressed air, material breaking cartridge having a quick opening charge release mechanism located entirely in the discharge end of the cartridge and including a pair of air pressure actuated valves, one of which is caused to open, by reducing the pressure of the air acting on a portion thereof, to effect automatic opening of the other, and both of which are automatically returned to their normally closed positions for subsequent operation of the cartridge.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this 2,720,168 Patented Oct. 11, 1955 Figure 5 is a transverse sectional view taken on line 55 of Fig. 4.

In the drawing, wherein for the purpose of illustration are shown the preferred embodiments of the invention, and first particularly referring to Fig. lb, reference character 6 designates a cartridge body having a chamber 7 therein from which the compressed gas charge is to be released. One end of the body 6 is closed by a threadedly connected charging cap 8 which has an inlet opening 9 formed in its end wall and a conical seating surface 11 surrounding the outer end of the opening. An internally and externally threaded annular projection 12 extends axially outwardly from the end of the charging cap 8 in concentric relationship with the conical seating surface 11.

A guard ring 13 and a coupling nut 14 are slipped over the end of a compressed gas feed line 15 through which gas is to be fed to the cartridge. The nut 14 is provided with an axially located bore 16 which is fitted onto the outer surface of the feed line 15 and the inner end portion of the bore 16 is flared outwardly to form a conical surface 17 to oppose the conical seating surface 11. When the coupling nut 14 is threaded into the annular projection 12, the end of the feed line 15 is flared outwardly and is gripped between the conical surfaces 11 and 17. The guard ring 13 is then threaded onto the projection 12 to form a protecting wall around the coupling members. The end portion of the guard ring 13 which projects outwardly from the charging cap 8 is formed with a radially inwardly directed flange 18 having a rounded surface 19 for engaging the feed line 15 to prevent damage thereto when the cartridge is angularly displaced relative to the feed line.

The inner end of the opening 9 in the charging cap' 8 is internally threaded for connection with the pipe or tubing 21 which extends axially through the cartridge body 6 to the opposite end of the cartridge, as later will be described. The pipe 21 is supported in its axial position at the end portion of the body member 6 opposite the charging cap 8 by the supporting spider 22 which is best illustrated in Figs. la and 3. This spider is formed of concentric outer and inner rings 23 and 24, respectively, which are maintained in fixed spaced relationship by spokes 25. The outer ring 23 is fitted into the bore of the body member 6 and the inner ring 24 is fitted onto the outer surface of the pipe 21.

Referring to Figs. 1a and 2, the discharge end portion of the cartridge body member 6, opposite the charging cap 8 is internally threaded at 26 for connection with an adapter 27. Sealing between the opposed surfaces of the body member 6 and the adapter 27 is provided by the O-ring 28 which is seated in groove 29 at the inner end portion of the adapter. The central portion of the adapter 27 is provided with two or more indentations 31 in its outer surface for cooperation with a spanner wrench which may be used in assembling and disassembling the threadedly connected parts. The outer end portion of the adapter 27 is externally threaded at 32 and the end edge is shaped to form an annular main valve seat 33.

A discharge section 34, formed with an internally threaded inner end portion 35, is threaded onto the end of the adapter 27 and is provided with a circumferentially alined row. of discharge or release ports 36 which are closely adjacent to the valve seat 33 and are of suflicient number and total cross-sectional area to efiect rapid release ofthe gas from the cartridge chamber 7; The discharge section 34. is tubular and has an inner diameter slightly: greater thanthat of the annular valve seat 33.

A- piston type main valve 37 is positioned in the discharge section 34 for longitudinal movement between its. seated and fully opened positions. This valve 37 is of hollow cylindrical construction and has an open inner endand an axially positioned passageway 38 through its outer wall. The open inner end of the valve is beveled at-itsperipher-y toprovide a seating surface 39 for engagement with the valve seat 33. The outer end portion of the valve 37 has an- O-ring 41 positioned in the circumferential groove 42 toprovide a seal between the valve and the inner surface of the discharge section 34. The valve 37, therefore, at all times seals the discharge ports 36.from.the interior of the discharge section 34 and, when the valve is in its closed position, seals the discharge ports from the charge release chamber 7. The longitudinally extending pipe 21 passes through the passageway 38 withrsutlicient clearance to provide a restricted flow path; between the chamber 7 and the interior of the dischargesection34 with the cross-sectional area of the flow pathsubstantially equal to the cross-sectional area of the passageway through the pipe.

Positioned in the opposite end of the discharge section 34;from the main valve 37 is a pilot valve housing 43 having a radially outwardly extending flange 44 at its middle portion which is rigidly clamped against the annular end surface 45 of the discharge section by an end cap-46. which is threadedly connected to the outer end portion of the discharge section. The portion of the pilotvalve housing 43 which extends outwardly from the flange 44. passes through an opening 47 in the end cap 46 and is drilled and threaded to receive the venting cap 48,. The portion of the pilot valve housing 43 which extends inwardly from the flange 44 is drilled to provide a .cylindrical pilot control chamber 49 therein. Sealing is provided between the pilot valve housing 43 and the inner surface of the discharge section 34 by an O-ring 51- which is seatedv in the groove 52 adjacent the radial flange 44. Positioned between the main valve 37 and the housing 43 is a spring 53 having its opposite end portions seated against radial surfaces 54 and 55 of the valve and housing, respectively, in surrounding relationship-. with the. inwardly projecting portion of the housing to urge the valve 37 toward its seat 33.

Formed-,withinthe discharge section 34 between the main valve 37 and the housing 43v is a main control chamber- 56' which isin communication with the charge release chamber 7through the restricted flow path that is formed between the pipe 21 and passage-way 38 in the. main, valve 37. Extending angularly inwardly through the housing 43 are passageways 57 which provide communication between the main control chamber 56 and the interior of the housing 43 between its pilot control chamber 49'and the inner end of the venting cup 48.

The outer end of the axially extending pipe 21 terminatesinthe inner end of the pilot control chamber 49. The space between the pipe 21 and the inner end of the housing 43 is closed by a washer 58 seated against the radial shoulder 59-at the inner end of the pilot control chamber, a cup leather 61 having its angularly disposed portions, abutting the washer 58 and the outer surface of the pipe 21, and an externally threaded nut 62 clamping the cup, leather and the washer against the shoulder. Thecup, leather 61 functions as a check valve permitting the flow-of gas fromthe pilot control chamber 49 into the main control chamber 56 but preventing the reverse flowof gas from the maincontrol chamber to the pilot control chamber. The cross-sectional area of the space between the washer. 58 ;and pipe 21 is substantiallyequal to -th at betwe en the. opening 38 and the pipe.

A piston type pilot valve 63 is movably positioned in the cylindrical pilot control chamber 49 and extends axially therefrom for engagement with the annular valve seat 64 formed by the inner end of the passageway 65 in the venting cap 48. Sealing between the valve 63 and the cylindrical wall of the pilot control chamber 49 is provided by an O-ring 66 seated in the peripheral groove 67 in the outer surface of the valve. The opening in the outer end of thepilot control chamber 49 is of sulficiently greater diameter than the valve 63 to permit gas flowing from the main control chamber 56 through) the passageways 57 in the housing 43 to act upon the annular outer surface 68' of the valve 63.

Radial passageways 69 in the venting cap 48 provide for the rapid discharge of gas through the axial passageway 65 when the cartridge is discharged.

The operation of the cartridge will be described as follows:

Thecartridge, in an uncharged condition but connected to a suitable source of supply of compressed air, or other gas, by the feed line 15, is placed in a previously prepared drill hole formed in the working face of the material to be broken down, such as coal in a mine. At this time the charge release chamber 7 of the cartridge body member 6 is sealed from the discharge ports 36 by the engagement of the main valve 37 with its seat 33 and by the O-ring 41. The main control and pilot control chambers 56 and 49, respectively, are in communication with each other through the unidirectional flow path formed by the cupleather 61 and are'in communication with the-charge release chamber 7 through the restricted flow path between the pipe 21 and the opening 38 in the main valve 37. The main valve 37 is initially moved into'its seated position by the spring 53.

The compressed air is delivered through the feed line 15 and the charging cap 3 into the pipe 21 for flow into the-pilot control chamber 49. The pressure of the gas delivered to the pilot control chamber 49, therefore,-will immediately move thepilot valve 63 into its seated position against the valve seat 64 to seal the passageways 57 in the housing 43 from the axially located passageway 65 in the venting cap48. During this charging of gas into the pilot control chamber 49; the gas is permitted to flow past the cup leather 61 into the main control chamber 56 and from themain control chamber 56 through the restricted passageway between the pipe 21 and the opening 38' in the mainvalve into the charge release chamber 7; The pressures in the pilot control chamber 49,- main control chamber 56 and charge release chamber 7, therefore, will be substantially equal during charging of the cartridge.

During charging, the main valve 37 will be maintained in its seated or closedposition by the force of the spring 53 andby the diflerential. forces acting on the opposite ends of the valve. area of the valve 37 exposed to the pressure in the main control chamber 56- is greater than the efiective surface area of the valve exposed to the pressure in the charge release chamber 7 so that the forces acting on the valve are unbalanced in a direction to maintain the valve in its closed position. Similarly, the pilot valve 63 will'be maintained in its..seated position by the differential forces acting on opposite end surfaces of the valve. The effective surface area of thevalve63 exposed to the pressure of the gas in the pilot control chamber 49 may be considered as being equal to the cross-sectional area of the pilot control chamber and the effective surface area on the opposed end of the valve may be considered as being equal to the cross-sectional area of the pilot control chamber 49 minus the cross-sectional area of'the passageway 65 in the venting cap 48'.

When the charge release, main control and pilot control chambers 7, 56, and 49, respectively, have received a sufficient volume of ;gas-to;raise; the pressures therein to the desired-work -performing value, as may be indicated by. a pressure guage, not-shown, located ataremote point Inother words, the effective surface I '5 in the feed line 15, an operator, also located at the remote point, should operate a three-way valve, not shown, to stop the flow of gas through the feed line and to vent the gas from the feed line to the atmosphere.

The venting of compressed gas from the feed line 21 will release the gas confined in the pilot control chamber 49 through the pipe 21 and will thereby quickly reduce the pressure in the pilot control chamber. The air confined in the main control chamber 56, however, will be prevented from flowing into the pilot control chamber 49 by the cup leather 61 so that the pressure of the air in the main control chamber will be much greater than the reduced pressure in the pilot control chamber. When the pressure of the gas in the pilot control chamber has been reduced to a value at which the force exerted on the valve 63 is smaller than the force exerted on the valve by the pressure of the gas in the main control chamber 56 acting through the passageways 57 and on the annular surface 68, the pilot valve will be quickly moved into a position at which the passageways 57 are in direct communication with the axially located passageway 65 in the venting cap 48. The gas inthe main control chamber 56 will thereupon be vented through the passageways 57 in the housing 43, and the axially located passageway 65 and radial passageways 69 in the venting cap 48.

The venting of the main control chamber 56 will quickly reduce the pressure in the main control chamber to a value at which the forces acting on the main valve 37 will be unbalanced in a direction to move the valve into its open position. In other words, the pressure of the gas in the release chamber 7 being much greater than that of the gas in the main control chamber 56, the valve will be opened by the greater pressure and the gas charge in the chamber 7 will be released through the charge release ports 36.

The successive operation of the valves 63 and 37 is extremely rapid. The release of the entire gas charge from the chamber 7 reduces the pressure in this chamber and the main valve will be returned to its seated position by the spring 53 to recondition the cartridge for a subsequent operation. The pilot valve 63, however, will remain in its opened position until gas is again admitted through the feed line 15 so that any residual pressure remaining in the cartridge after the main valve 37 has been returned to its seated position will be bled from the cartridge through the venting cap 48.

Figs. 4 and 5 illustrate a modified form of check valve which may be substituted for the cup leather assembly illustrated in Fig. la to permit unidirectional flow of gas from the pilot control chamber 49 to the main control chamber 56. In this modified form of check valve assembly, the nut 71 is threaded into the inwardly extending end portion of the housing 43 and a seal is provided between the nut and the outer surface of the pipe 21 by an O-ring 72 seated in the groove 73 in the inner surface of the nut. A groove 74 is formed in the outer surface of the housing 43 and has a fiat bottom surface 75 and a passageway 76 extending from the fiat bottom surface into the pilot control chamber 49. Positioned in engagement with the surface 75 is a flap valve 77 of any suitable flexible material which covers the outer end of the passageway 76 and extends to one side thereof. This flap valve 77 is fastened in contact with the surface 75 by a machine screw or the like 78 at a point which is spaced from the passageway 76.

It will be readily apparent that the pressure of the gas in the pilot control chamber 49 will cause the free end portion of the flap valve 77 to be lifted away from its position across the end of the passageway 76 to permit the gas to flow freely from the pilot control chamber into the main control chamber 56. When the pressure of the gas in the main control chamber 56 exceeds the pressure in the pilot control chamber 49, however, the flap valve 77 will be moved into contact with the surface 75 across the outer end of the passageway 76 to prevent the flow of gas from the main control to the pilot control chamber.

In all other respects a cartridge embodying the modified form of check valve mechanism illustrated in Figs. 4 and 5 functions in the same manner as the cartridge previously described. A detail description of theoperation of the cartridge, therefore, will not be repeated.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same and that various changes in shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, I claim:

1. In combination, a cartridge having arranged successively longitudinally thereof a chamber from which a material breaking charge of compressed air is to be released, lateral gas charge release ports, a main control chamber and venting ports, a first valve movably positioned between said release and main control chambers for controlling the release of the gas charge from said gas release chamber through the release ports and having a greater eifective surface area exposed to the pressure of the gas in the main control chamber than is exposed to the pressure of the gas in said release chamber, means for equalizing the gas pressures in said release and main control chambers, means forming a pilot control chamber adjacent said venting ports, a second valve movably positioned between said main control and pilot conrol chambers for controlling the release of gas from said main control chamber through said venting ports and having a greater effective surface area exposed to the pressure of the gas in the pilot control chamber than is exposed to the pressure of the gas in said main control chamber, means permitting the unidirectional flow of gas from the pilot to the main control chamber, and means for introducing compressed air to said pilot control chamher for flow into said main control and release chambers to charge the cartridge and for venting compressed air from the pilot control chamber to successively actuate said second and first valves for movement into their open positions.

2. In combination, a cartridge having arranged successively longitudinally thereof a chamber from which a material breaking charge of compressed air is to be released, lateral gas charge release ports, a main control chamber and venting ports, a first valve movably positioned between said release and main control chambers for controlling the release of the gas charge from said gas release chamber through the release ports and having a greater effective surface area exposed to the pressure of the gas in the main control chamber than is exposed to the pressure of the gas in said release chamber, resilient means urging said valve into its closed position, means for equalizing the gas pressures in said release and main control chambers, a valve housing mounted in said main control chamber and having a pilot control chamber therein, a second valve movably mounted in said housing between said main control and pilot control chambers for controlling the release of gas from said main control chamber through said venting ports, said second valve having a greater effective surface area exposed to the pressure of the gas in the pilot control chamher than is exposed to the pressure of the gas in said main control chamber, a check valve between the pilot and main control chambers for permitting unidirectional flow of gas from the former to the latter, and means for introducing compressed air to said pilot control chamber for flow into said main control and release chambers to charge the cartridge and for venting compressed air from the pilot control chamber to successively actuate said second and first valves for movement into their open positions.

3. In combination, a cartridge having arranged successively longitudinally thereof a chamber from which a material breaking charge of compressed air is to :be released, ilateral gas charge release ports, a main control chamberaud-venting ports, a first valve movably-positioned between said release and 'main control chambers foricontrolling the .release of the gas charge from said gasrrelease chamber through the release ports and having a greater ,eifective surface area exposed to the pressure of *thegas in the main control chamber'than is exposed'to the pressure of the gaslin said release chamber, said valve having ,a restricted flow path therethrough for equalizing the gas .pressures in'said release and main control chambers, :a spring urging said valve into its closed position, means forming a pilot control chamber adjacent said venting ports with an annular passageway between said pilot control and main control chambers, a cup leather positioned-in saidannular passageway for permitting unidirectional-liowiof gas from the pilot control to the main control chamber, a second valve movably positioned between said main control and pilot control chambers for controlling the release of gas from said main control chamber through said venting ports and having a greater effective surface areaexposed to the pressure of the gas in the pilot-control chamber than is exposed to the pressure of the gas in said main control chamber, and means for-introducing compressed air to said pilot control chamber for flow into said main control and release chambers to charge the cartridge and for venting compressed air from the pilot control chamber to successively actuate said second and first valves for movement into their open positions.

4. In combination, a cartridge having arranged successively longitudinally thereof a chamber from which a material-breaking charge of compressed air is to be released, lateral gas charge release ports, a main control chamber and venting ports, a first valve movably positioned between said release and main control chambers for controlling the release of the gas charge from said gas release chamber through the release ports and having a greater effective surface area exposed to the pressure of the gas in the main control chamber than is exposed to the pressure of the gas in said release chamber, said valve having a restricted fiow path therethrough for equalizing the gas pressures in said release and main control chambers, a spring urging said valve into its closed position, means forming apilot control chamber adjacent said venting ports with'a passageway between said pilot control and main control chambers, a check flap positioned across the end of said passageway at the main control chamber for permitting unidirectional flow of gas from the pilot control to the main control chamber, a second valve movably-positionedbetween said main control and pilot control chambersfor controlling the release of gas from said main control chamber through said venting ports and having a greater effective surface area exposed to the pressure of the gas ,in the pilot control chamber than is exposed to the pressure of the gas in said main control chamber, and means for introducing compressed air to said pilot control chamber for flow into said maincontrol and release chambers to charge the cartridge and for venting compressed air from the pilot control chamber to successively actuate .said second and first valvesfor movement intotheir open positions.

5. In combination, a cartridge having arranged successively longitudinally thereof a chamber from which a material breaking charge of compressed air'is to be released, lateral .gas charge release ports, a main control chamber and-venting ports, a first-valve movably positionedbetween said release and main control chambers for controlling the release of the gas charge from said gas-release chamber ,throughthe release ports .and having a greater ,efiective surface area exposed to the ,pressure of the gas in :the :main control chamber than is exposed tothe pressure ,ofthe,gas;in said release chamber, said valve having ;a longitudinal opening therethrough, resilientimeans urgingsa'idzvalve into its closed position, means forming apilot control chamberadjacent said-venting ports,;a second .valve.rmovably-positioned between said main control and pilot control chambers for controlling the release of gasfromsaid-maincontrol chamber through said ventingports Land havinga greater efiective surface area exposed to :the pressure'ofthe gas in the pilot control chamber than is exposed to the pressure of the gas in :said main control chamber, :means permitting the ,unidirectional flow of .gas from "thepilot to the main control chamber, and a'tubular member :extending longitudinally through saidchargetrelease chamber, the opening in said first valve and said main control chamber into said pilot control chamber for introducing compressed air .directly into the latter and for ventingcompressed airtherefrom to successivelyactuatesaidsecond and first .valves for movement into their topentpositions said :tubular member and the Lopening in said first valve having clearance ,therebetween to provide .a restricted flow path between the charge release and main control chambers through which the cartridge is: charged.

-6. In combination, aca-rt-ridge'having arranged successively longitudinallythereof .a chamber fromwhich a material breaking charge of compressed air is to be released, lateral gas charge release ports, a main'control chamber and venting ports, a irst valve movably positioned between said release -and-main control chambers for controlling 'the release-of the gas charge from said gas release chamber through'the release ports and having a greater eifective surface area exposed to the pressure of the gas in the maincontrol chamber thanis exposed to the pressure of the gasin said release chamber, said valve having a longitudinal opening therethrough, a spring urging said-valve into its closed-position, acylindrical valve housing mounted -in-said main control chamber and havinga pilot control chamber 'therein, said housing having .an opening in alinement with-the opening-in said first 'valve, a second valve for controllingthe 'release'of-gas-from'said main control chamber through said venting ports having a valve operating piston mounted in said pilot control chamber, said piston having a surface exposed to-the pressure of the gas in said main control chamber and an opposed surface of greater effective area exposed to the pressure of the gas in said said pilot control chamber, 'a tubular member extending longitudinally through said release and main control chamber and the alined opening in said first valve and said housing for introducing compressed air directly into-the pilot control chamber and for venting compressed air'therefrom, and a check valve between the pilot and main control chambers for permitting unidirectionalfiow of gas from the former to the-latter, said first valve having a restricted flow path therethrough between the charge release and main control chambers through which the cartridge is charged.

=ReferencesiCited in thefileiof this patent UNITED STATES PATENTS 2,083,697 Dull June 15, 1937 2,083,707 Harris June 15, 1937 2,083,735 Noble June 15, 1937 2,435,116 Armstrong Jan. 27, 1948 2,591,529 Filstrup Apr. 1, 1952

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