US2083729A - Material-breaking apparatus - Google Patents

Description

June 15, 1937. A MAXSON 2,083,729

riginal Filed April 27, 1935 mw f\\" nor) Patented June 15, 1937 MATERIAL-BREAKING APPARATUS Application April 27, 1935, Serial No. 18,641 Renewed July 30, 1936 17 Claims.

My invention relates to apparatus for the breaking down of coal and other materials by the release from suitably positioned containers of relatively large charges of a highly compressed gaseous medium, and more particularly to improvements in devices of the so-called pre-charged variety for that purpose.

In the breaking down of coal and other materials, and for similar operations, it has been f found practicable and highly advantageous to employ charges of highly compressed gaseous media instead of explosives. There are two general methods of this. One involves the lodging of an unfharged shell or container in a suitably formed hole in the material to be fractured, and

then forcing into the container a charge of highly compressed gaseous medium, and thereafter, in an appropriate manner and in the same sequence of operations, effecting a release of the stored charge and the breaking thereby of the material in which the container is lodged. The other method comprises the pre-charging of containers at an appropriate and convenient location, the transportation of these containers to the D desired point of use7 the preparation of holes to receive them, the setting in operation of an automatic time-delay device for effecting release of the charge, the immediate positioning of the container fully in the position which it should occupy upon release of its charge, and, after the lapse of the predetermined time delay inherent in the operation of the automatic discharging device, release of the charge, the operator having, during the time delay period, retired to a place of safety. rihe present invention. relates more particularly to this latter typ-e of material-breaking apparatus, and an object of the invention is to provide an improved safety arrangement for precluding even the minutest possibility of unintended release of the charge from a pre-charged container.

Such pre-charged containers of the character hereinabove mentioned comprise a charge release valve held in closed position by the entrapping of a charge oi highiy compressed medium in a chamber where it acts upon a discharge valve closing plunger of greater effective cross sectional area than the discharge valve; and release of the charge is effected by the venting of the pressure entrapped in the chamber mentioned. Venting is normally effected by the unseating of a check valve which is held in closed, pressure-trapping position, both by'aspring and by the pressure of the entrapped medium. Such valves have been known to remain leak-prooi for many weeks, but in the interest of safety the provision of an additional assurance against unintended discharge, which might occur were the check valve to be unseated accidentally, or to leak, is desirable.

From one of its aspects, my invention comprises the provision of a valve which positively interrupts communication between the control chamber and the check valve at all times except When such communication is desired in order that discharge may be effected. From another aspect, my invention comprises the provision of means for maintaining constantly replenished from the main charge storage space of the shell, the pressure within the control chamber, should there be any leakage at the check valve. From still another aspect, my invention includes a combination of the functions last described, with an interruption of the replenishing circuit, as it were, when discharge is desired; and in diierent embodiments my invention may comprise wholly` manual means for effecting the desired results, or it may comprise an embodiment in which no manual operation is requisite and through a special check valve arrangement complete safety is effected.

It is another object of'my invention to provide an improved, safety-type, pre-charged shell. It is a further object of my invention to providean improved, safety-type, pre-charged shell requiring a deliberate operation on the part of the operator to prepare the shell for release of its charge. It is still another object of my invention to provide an improved pre-charged shell having an improved check valve associated therewith which in closed position insures maintenance of the pressure in the control chamber of the shell, and in its open position interrupts communication between such control chamber and the source of pressure medium supply with which the same communicates when the check valve is closed. Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawing, in which two illustrative embodiments of the invention are shown,-

Fig. 1 is a central longitudinal section through a cartridge or shell in which one illustrative embodiment of the invention is incorporated.

Fig. 2 is an enlarged section through a portion of the outer end of the shell of Fig. 1.

Fig. 3 is a transverse section on a plane corresponding to the line 3-3 oi Fig. 2.

Fig. 4 is a fragmentary section corresponding to Fig. 2, showing the safety valve in a diiierent position.

Fig. 5 is a View similar to Fig. 2, showing a modification.

Fig. 6 is a transverse section on a plane corresponding to the line 5 6 of Fig. 5.

The invention, in both illustrative embodiments, is shown incorporated in a shell which is ofthe general type disclosed in a co-pending application of one Frank H. Armstrong, Serial No. 718,175, led March 30, 1934 (see Fig. 12), and this shell is of the type which is designed to be charged at some central charging station and then transported in a precharged condition to the point of use.

The shell comprises an elongated cylindrical container I having a chamber 2 for receiving a charge of highly compressed gas. At 3 there is threadedly connected to the inner end of the container a discharge cap 4, While a control cap 5 is threadedly connected at 6 at the opposite end of the container I. The discharge cap 4 comprises a central discharge chamber l which communicates through a series of appropriate discharge ports 8 with the exterior of the shell. A conicalcharge release valve 9 seats upon the inner end of the discharge cap 4. The valve 9 is provided with an axial guide extension l0 which is guided in a bore II formed in the discharge cap. The control cap 6 has a bore I2 in which a plunger I3 is reciprccable. A valve rod lli connects the valve 9 and the plunger I3, and extends axially through the pressure chamber 2. A keeper I6, threadedly supported by the rod I, holds a cup leather II against the plunger i3. and precludes leakage of high pressure medium along the control chamber past the plunger to a space l5 at the outer side of the plunger I3. A suitable metallic, axially perforated septum I8 supports a hat leather I9 which cooperates with the exterior of the rod I 4 and acts as a check valve to permit the passage of pressure from within the chamber 2 to a space 20 between the plunger and the septum, While precluding reverse ow. The valve rod is axially bored at 2|, and the bore 2l communicates, under the control of a spring seated check valve 22, controlling an opening 23 in the plunger I3, with the chamber l5; and at its other end the bore communicates through passages 24 with the chamber 2. A bleed passage 25 of small area is provided at a suitable point to permit leakage out, of the pressure entrapped within the chamber 20, after the charge has been released, in order that the valve 9 may be more readily reseated.

According to the conventional design of discharge caps of the type described, a passage 26 is arranged to connect, upon the opening of a spring-seated check valve 2l, the chamber i5 with the exterior of the discharge cap at the outer end of the latter, as at 28.

Various means are provided for the effecting of the unseating of the valve 2I when discharge is desired, and I have illustrated a discharge gun which is the invention of one Frank H. Armstrong, above mentioned, for the purpose of showing one type of mechanism which may be used for effecting shell discharge when desired. This gun is designated 30 and comprises a casing 3| threadedly secured, as at 32, to the outer end of the control cap 5. The casing 3l comprises a cylinder bore 33 coaxial with the shell and containing a reciprocable piston 34. A watercontaining chamber 35 is arranged at the outer end of the gun casing, and a passage 35, controlled by a normally closed needle valve 31, is adapted, when the needle valve is opened, to

conduct water into the space to the outside of the plunger 34. The plunger 34 is normally maintained in its retracted position (that shown in Fig. 1) by a spring 38, and carries a cage 39 containing calcium carbide. Obviously, when the shell is horizontal, a material amount of water must flow from the storage chamber 35 into the space to the outside of the plunger 35 before the water will reach the carbide in the cage 39. Accordingly, a denite time delay may be assured after the valve 31 is opened, by properly proportioning the passage 35 and the volume of the space to which the Water is admitted in order that it may act upon the carbide. One or more radial discharge passages l0 extend from the space 4l, which is formed between the forward end of the gun and the outer end of the control cap; and upon the generation of pressure sufficient to move the plunger 34 to unseat, through its operating stem 152, the check Valve 2l, the pressure within the chamber I5 will be released through passage 26, past valve 2l, through passage 28, space 5l, and port means 40, to Vent the chamber I5 and permit the pressure in the space 20 to move the valve 9 to charge releasing position, and there hold it.

The mode of operation of the device will be clear from what has just been said, but it may be worth while to state that when it is desired to release the charge from a shell or container a head 39 will be applied to it; the shell or container will be placed in the hole which it is to occupy when the charge is released; it will be brought into a position where the passage 36 is at the bottom; the valve 3l will be opened; the shell will be shoved home in its hole; a suitable quick-tamping may be thrust into the hole outside the container, if desired; and the operator will retire to a safe position; and, after a predetermined time, determined by the proportioning and design of the parts, perhaps one or two minutes, the water will attain sufficient contact with the carbide to generate pressure enough to unseat the valve 2l, vent the space I5, and cause release of the charge.

Now, as pointed out above, while shells of this character will maintain the pressure in the space l5 for long periods, it would be safer to prevent completely any possibility of premature discharge due to release or leakage out of the pressure within this chamber; and in the embodiment shown in Figs. 1 to 4 inclusive, I provide a manually rotatable plug valve "l5 in a bore 46 which intersects the passage 26, and provide in this plug valve a through passage 4l which, when alined with the passage 25,permits flow outwardly from the chamber I5 through the passage 25 to the check valve 2, and past the latter, if the latter be opened, to atmosphere. The valve l5 is suitably packed at its opposite ends, as indicated at 49 and 50, and has a polygonal socket 5I in its larger end, with which a wrench may cooperate in moving the valve between its opposite positions. A passage 52 extends from the chamber I5 into communi cation with the bore lli at a point at right angles to the communication with the latter of the passage 29, and a passage 53 having communication with the bore 55 in alinement with the passage 52, extends forwardly to any suitable point whence pressure may be conducted to the chamber I5, either to the chamber 2 directly or, more simply and equally satisfactorily, to the space 25. When the valve l5 is in the position shown in Fig. fl, passages 52 and 53 are connected so that the same pressure will prevail in chamber I5 that prevails in chamber 20, and therefore the valve 9 will be positively maintained closed. At the same time, the passage 26 is cut on" from communication with the valve 2l and discharge orifice 28, and the cartridge is doubly secured against accidental discharge. This is the position of the valve 45 used during transportation of the cartridge, and the valve is maintained in this position until just prior to the time when discharge is desired.

When it is desired to discharge the cartridge within a moment or two, the valve 45 will be turned to the position shown in Figs. 1 and 2, and this will interrupt communication between passage 53 and passage 52 and prevent any escape of pressure from the space 20, and will open communication between the space I and the check valve 2l; It will be evident that double assurance against premature discharge is provided by this device, and that the operator must deliberately turn the valve 45 to discharging position in order that the shell may be discharged.

In the species of the invention shown in Figs. 5 and 6, the need for a manual operation in order to permit discharge, is dispensed with, but the H possibility of lowering of the pressure within the chamber l5 through leakage is avoided by provision for continuous maintenance of the same pressure in that chamber as in the space 2B'. 'Ihe passage 53 corresponds, in this form of the invention, with the passage 53 of the rst species. The passage 52 corresponds with the passage 52 of the first species. However, instead of using a mere ball check, a plunger type check valve is provided at 60, and this plunger type check valve has a peripheral groove El which connects the passages 52 and 53' when the forward conical portion 82 of the valve device 60 is seated. A spring 63 maintains the valve device B0 normally in seated position. The valve device 60 is reciprocable in a chamber 64 and has a forward surface S5 partially counterbalancing the pressure upon the rear end of the valve. Bypass passages 66 extend outside the chamber 64 and connect the front and rear ends thereof, so that on unseating or the conical portion 62 the pressure may pass freely past the valve device from the chamber I5 outwardly. It will be obvious that in this form of the invention the replenishment feature is present; and that loss of pressure from chamber Eil upon release of the charge by unseating the valve li is precluded because the groove 6I will not connect the passages 52 and 53' when the valve device 60 is moved from its seat by the operating stem 42. However, the feature of a double guard is not provided in this form of the invention. The shell charging opening is shown in several figures at li).

From the foregoing description, it will be evident that I have provided an improved apparatus for the safe breaking down of coal and other materials; that in each of its embodiments illustrated, premature discharge due to reduction of pressure in the control chamber is prevented, and that in one of its embodiments this is prevented not only by assuring maintenance of like pressure conditions in that chamber and in the space where pressure acts to effect opening of the discharge valve, but also venting of the control space is positively precluded. It will be obvious that in both forms the device is simple, that it is foolproof, and that additional assurance against possible premature discharge may be furnished in diierent degrees, as may be desired by the user of the shells.

While I have in this application specifically described two embodiments which my invention may assume in practice, it will be understood that these are shown for illustrative purposes only and that the invention may be further modified and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including an area effective when subjected to charge pressure to maintain the charge release valve closed,

and means eiiective on release ofrpressure nfrom Y said area to open the charge release valve, and means including a vent passage and controlling means therefor for releasing pressure from said area when charge release is desired, and means for selectively interrupting communication between the ends of said vent passage and subjecting said area continuously to charge pressure and opening such communication and cutting 01T said area from charge pressure supply.

2. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including an area effective when subjected to charge pressure to maintain the charge release valve closed, and means effective on release of pressure from said area to open the charge release valve, and means including a vent passage and controlling means therefor for releasing pressure from said area when charge release is desired, and means including a valve intersecting said vent passage for selectively interrupting communication between the ends of said vent passage and subjecting said area continuously to charge pressure and opening such communication and cutting oi said area from charge pressure supply.

3. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including an area effective when subjected to charge pressure to maintain the charge release valve closed, and means effective on release of pressure from said area to open the charge release valve, and means including a vent passage and controlling means therefor for releasing pressure from said area when charge release is desired, and means including a` valve intersecting said vent passage and having-but a single flow passage therethrough for selectively interrupting communication between the ends of said vent passage and subjecting said area continuously to charge pressure and opening such communication and cutting off said area. from charge pressure supply.

4. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including opposing areas, one effective on release of pressure from the other to open the charge release valve, and the other effective when subjected to pressure to maintain the charge release valve closed irrespective of pressure on the iirst, and means including a vent passage and a valve device for venting the pressure on the second mentioned area when charge release is desired, and safety means for precluding acciciw dental charge release including a manually operable valve in one position closing the vent passage completely.

5. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including opposing areas, one effective on release of pressure from the other to open the charge release valve, and the other effective when subjected to pressure to maintain the charge release valve closed irrespective of pressure on the r'st, and means including a vent passage and a valve device for venting the pressure on the second mentioned area when charge release is desired, and safety means for precluding accidental Ycharge release including a manually operable valve in one position closing the vent passage completely and opening communication between said areas.

6. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the position of said charge release valve including opposing areas, one effective on release of pressure from the other to open the charge release valve, and the other eiective when subjected to pressure to maintain the charge release valve closed irrespective of pressure on the first, and means including a vent passage for venting the pressure on the second mentioned area when charge release is desired, and safety means for precluding accidental charge release including a valve having a passage and in one position closing said vent passage and opening communication through its passage between said areas and in another position opening communication through said passage between portions of said vent passage.

7. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the latter including an area effective when subjected to pressure to maintain the charge release valve closed and an area operative on venting of said first mentioned area to open the charge release valve, venting means for the first mentioned area, and means operative while said venting means is closed to connect said areas in communication with each other.

8. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the latter including an area effective when subjected to pressure to maintain the charge release valve closed and an area operative on venting of said first mentioned area to open the charge release valve, venting means for the irst mentioned area, and a valve operative in diierent positions to close said vent passage and effect connection of said areas in communication with each other and to open said vent passage and int-errupt communication between said areas.

9. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the latter including an area effective when subjected to pressure to maintain the charge release valve closed and an area operative on venting of said rst mentioned area to open the charge release valve, venting means for the iirst mentioned area, and a reciprocable check valve operative in different positions to close said vent passage and effect connection of said areas in communication with each other and to open said vent passage and interrupt communication between said areas.

10. In combination, a container for a charge of highly compressed gaseous medium having a charge release valve and means for controlling the latter including an area effective when subjected to pressure to maintain the charge release valve closed `and an area operative on venting of said rst mentioned area to open the charge release valve, venting means for the first mentioned area, and a rotary valve operative in different positions to close said vent passage and eiect connection of said areas in communication with each other and to discontinue its closure of said vent passage and interrupt communication between said areas.

11. In combination, a container for receiving a high pressure charge and having a charge release valve, differential fluid pressure means operable to hold said valve closed and to open said valve to eiiect release of the charge, means operable to effect the differential fluid pressure condition which causes opening of said valve, and means for assuring a :uid pressure condition which will hold said valve closed until opening of the valve is desired.

l2. In combination, a container having a charge of VYmaterial breaking medium and charge release means, and means for controlling the latter including an area eiective when subjected to pressure to maintain the charge release means closed and an area operative on venting of said irst-mentioned area to open the charge release means, venting means for the rst-mentoned area, and means operative while said venting means is closed to connect said areas in communication with each other.

i3, In combination, a container for receiving a charge of material breaking medium and having a charge release valve and a control chamber, a plunger in said chamber operatively connected to said valve, said plunger being subject to control chamber pressure conditions which either cause the plunger to hold said valve closed or to open said valve, means for establishing the control chamber pressure condition which will cause the plunger to open the valve, and means operative While the aforesaid means is inactive to assure maintenance of the control chamber pressure condition which will cause the plunger to hold the valve closed.

14. In combination, a container for receiving a charge of material breaking medium and having a charge release valve, and a control chamber, a plunger in said chamber operatively connected to said valve, said plunger being subject to control chamber pressure conditions which either cause the plunger to hold said valve closed or to open said valve, means for establishing the control chamber pressure condition which will cause the plunger to open the valve, and manually operable means to prevent operation of the aforementioned means from effecting a control chamber pressure condition which will cause the plunger to open the valve, and means to assure maintenance of the control chamber pressure condition which will cause the plunger to hold the valve closed.

15. In combination, a container for receiving a charge of material breaking medium and having a charge release valve and a control chamber, a plunger in said chamber operatively connected to said valve, said plunger being subject to control chamber pressure conditions which either cause the plunger to hold said valve closed or to open said valve, means for establishing the control chamber pressure condition which Will cause the plunger to open the valve, and manually operable means to preventI operation of the aforementioned means from eiecting a control chamber pressure condition which will cause the plunger to open the valve.

16. In combination, a container for receiving a charge of material breaking medium and having a charge release valve and a control chamber, a plunger in said chamber operatively connected to said Valve, said plunger being subject to control charnber pressure conditions Which either cause the plunger to hold said Valve closed or to open said valve, means for establishing the control chamber pressure condition Which will cause the plunger to open the valve, and means for assuring maintenance of the control chamber 20 pressure condition which will cause the plunger to hold the valve closed, and valve means for controlling operation of both of the aforementioned means.

17. In combination, a container for receiving a charge of material breaking medium and having a charge release valve and a control chamber, a plunger in said chamber operatively connected to said Valve, said plunger being subject to control chamber pressure conditions which either cause the plunger to hold said Valve closed or to open said valve, means for establishing the control chamber pressure condition which Will cause the plunger to open the Valve, means for assuring maintenance of the control chamber pressure condition which will cause the plunger to hold the valve closed, and Valve means under manual control for permitting operation of only one of said aforementioned means at any one time.

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