US2842056A - Explosive charge - Google Patents

Description

July 8, 1958 R. KLoTz EXBLosIvE CHARGE 2 Sheets-Sheet 1 Filed May 4, 1954 INVENTOR.

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July 8, 1958 R. L. KLoTz ExPLosIvE CHARGE 2 Sheets-Sheet 2 Filed May 4, 1954 INVENTolL ff@ 2,842,056 j l g EXPLosIvE CHARGE t Y Robert L. Klotz, Conyngham, Pa., assignor-'to Seismograph Service Corporation, Tulsa, Okla., a corporation of Delaware Y Application May 4, 1954,-seriaiN0. 427,457

V11 claims. y(ci. 1oz-'24) The present invention relates to explosive charges and Ymore particularly to improved facilities for securing a Aplurality 'of explosivecartridges together in end-to-end relationship tol form an elongated explosive column, and

for insuring complete detonation ofthe entire column of explosive cartridges. Y l Y One method of insuring complete detonatio-n of a long column* of explosives of the type commonly used in seismic'survey operations, mining, quarrying, and similar operations, is described and claimed in copending application Serial No. 746,578, led May,7, 1947, 'by Robert L. Klotz, Jr., and assigned to the same assignee as the present invention, which application matured into Patent l No. 2,683,414 on July 13, 1954. The above identified application discloses an arrangement wherein a plurality of cartridges,lat least some of which have jet forming cavities in one end,y are aligned in end-to-end relationshipl to form an explosive column of the desired length. When the column is detonated,tthe jet forming .cavity in the end of each cartridge of the column which is so equipped produces an explosive jet effect which is directed into the next adjacent cartridge, thereby to strengthen and revitalize the detonating wave traveling along the column. The present invention relates to improved facilities for instrumenting the arrangement disclosed in the `identiied, Klotz application ina simple and economical manner and` for securing the explosive cartridges together tofformY the. `desired elongated columnar charge.

It is an object-of the present inventionto provide im- 'proved `facilities for insuring Vcomplete detonation of all Yof v,the cartridges in -an elongated columnar charge.

Y Itis another object of the invention to providey irri-- nted States Patent lCC.

of the cartridges embodied in the 4explosive charge shownY in Fig.,1;

Fig. 3 is la sectional view taken along/the line in Fig. 2; o

Fig. 4 illustrates a modiedembodirnent of the inven-r tion; f

Fig. 5 is a sectional view Ytaken along Fig. 4; e Fig. 6 is a partial sectional view illustrating a further theY ,inf

' embodiment of the invention; and

` shooting operations.

vvention, each adjacent pair vof cartridges is connected and secured together by means Vof a hollovvlpin'1`6-theV ends of which are inserted into the explosive material Fig. 7 is a sectional'view taken along Vthe line 7-7 in Fig. 6.

Referring now to the drawings and-more particularly to Fig. `1v thereof, Vthere is illustrated an elongated ex-V plosive charge or column 10 comprising a plurality of explosive cartridgesY 12 which are arranged in end-to-end relationship in a shot hole 11 in the manner Aconventionally employed kin quarry mining operations and seismic i Inaccordance withthe Vpresent infv of the two connected cartridges 12. This pin is providl ed with end Wall parts which define a jet forming .cavity` of the other connected cartridge.

tridges may also be further secured togetherbythe'conproved facilities Vfor connecting and securing together A' Y two explosive charges which areV so formed and varranged that a jet forming cavity is formed in one of thecartridges y' which :acts to produce an explosive' jet upon detona#v tion of the one cartridge which is directed into the other cartridge.

vIt is a further proved connecting'pin for'nterconnecting two explosive cartridgesV in an elongated -explosive charge and vfor producing an explosive jet at one end of one ofthe cartridges which isdir'ected Aintothe Aother ofthe cartridges. upon -fdetonation of the one'cartridg'e'.

.'Accordingtolstill another object ofthe invention, the

'present improved pin is effective to produce the desired explosivejet regardless of whichv of the two which' the pin 'connects is detonated first.

*Further objects andv advantages'of the present invencartridges tion will become apparentasthe following description proceed, and theV features of novelty which characterize thebinv'enti'on will befpointed outwith particularity in the claims vannexed to and forming-apart'of this specification'.ij l' For a `better understandingv of the present invention, referencemay'b'ehad tothe accompanying drawings in which#vr Y object of theinvention to provide anim-VV -in the explosive material of one of theY connected cartridges which acts to produce an explosive jet upon detonation of the one cartridge which forms in and istransmitted through the hollow pin into the explosive material ventional arrangement knownk as taping or lathing', in which one or'more lathsr, Such as. the latlis-lj'are bridged across the junction points 'betweeneafch pairf'off adjacent charges 12 andare tapedto'these cartridges vas` indicated at 14 and 15 to producea rigid or semirig'id` elongatedY charge. tridge connection illustrated in Fig. 4 may be used in 4addition to the connecting pins 16, Iif deemed desirable;V

However, when the present improvedconnectingpinsf16A are employed to interconnect thecart'ridges 13,2, the sleeve` couplings or taping orlathingvarrangements are notY ordinarily required for reasonsV 'which will', beappar-ent from the following explanation. However, Vif such conventionalconnecting arrangements are used Vin fcorrlbina-Y tion with the present improved Vconn'ectingpin'g ian exi tremely sturdy explosive .column capable ofwithstandingY themost' severe conditions of loadingmay be eas/,ilygand quickly assembled.l j 1 A 'It is well known that the detonation or Ypropagation wave traversing a column of explosive material tends to.-

become less intense the further the detonating wave trav-` els from thepoint of initiation. Ihis tendency increases` as the diameter of the explosive columnV decreases. 'It' also increases as the pressure, such asthe fluid ,tamping VV pressure used in the shot hole increases, and as theV sensitivity of the explosive material used is decreased. As

a consequence, only a portion of the explosive materialV provided in a ylong column of low sensitivity, explosive material may be exploded in response to detonation lof the lcolumn latrone end thereof.Y Moreover, when-the column is Vsectionalized, as by 'stacking anumber of car-n tridges in the manner described above, any foreign inat- V ter such as dirt, water, etc., which may` inadvertently get between the ends of any pair of abutting car'tridg'esfin'Y latented July 8, 1958 I-f desired; the 'car-vr Alternatively, the sleeve type'offfc'ar-- .g

many cases has the effect of attenuating the detonating wave as it travels from one cartridge to the abutting cartridge to the point where the abutting cartridge is not detonated. Any such undetonated explosive material used in a given charge is not only a waste of material, but, in addition, constitutes an1 explosives hazard which remains after the blasting or shooting operation is com'- pleted. The problem as thus outlinedis' solved in a' simple and economical manner by employing the present improved pins 16 to interconnect and bridge the cartridges 12 in the manner more fully explained below.

As shown in' Fig. l of the drawings, each of the cartridges 12 comprises a suitable container 17 of generally cylindrical configuration, within which is contained the explosive material 18 of the cartridge. in accordance with conventional practicejthe containers 1"? are of a non-metallic packaging material, such as heavy cardboard, which is capable of being perforated by the pointed ends of the hollow connecting pins 16. For the purpose of producing the desired jet forming cavity in the explosive material into which either end of the pin 16 is inserted, this pin is provided with thin end wall parts forming the pointed ends 16a and 16h. These end Wall parts also act as liners for the jet forming cavities which theyVV form in the explosive material of the cartridges 12 into which they are inserted. if required by the character .of the container material, the holes through which the ends of the pins are inserted into the cartridges may be prepunched on the job by using a pointed brass or bronze punch for the purpose. The two pin ends are connected by a hollow body portion 2t? of uniform diameter, in which an explosive jet may form and through whichthe explosive jet may be transmitted from the explosive'materialof one connected cartridge 12 into the explosive material of the other connected cartridge 12. The pin 1 6 is formed of relatively rigid material such as molded plastic, metal, glass, ceramic, or the like, and the end portions 16a and 1Gb of the pin are illustrated in the drawing as having a substantially conical shape although, as will become evident from the following explanation, these end portions may have other configurations, if desired.

In forming the column of explosive cartridges 12, one end of each pin 16 is driven or pushed by hand or other suitable means, if necessary, into one end of a cartridge 12, leaving approximately half of thc pin and one pointed endi exposed. The exposed half of the pin 16 is then pushed into the next adjacent cartridge in the columnas shown in Fig. l ofthe drawings. This operation is repeated until a complete column 1d is formed containing the desired number ofcartridges. In this connection, it should be noted that the pins 16 may be first inserted either into the top of each cartridge and the next succeeding cartridge dropped thereon or, alternatively, the pin may be insertedinto the bottom of a cartridge and the cartridge and pin may be dropped onto the next lower cartridge. In order to insure that the pin 16 will positively engage the explosive material within the containers 17 of the interconnected cartridges and to prevent inadvertent withdrawal of the pin, the sides of the pin are oppositely toothed or serrated as indicated at 21 and 22. At the center o f the pin, the serrations are omitted to provide an annular recess 23 of somewhat reduced ydiameter for receiving the edges of the perforated cartridge container end walls through which the pin extends.

Although the end Walls 16a and 16e of the pin 16 are illustrated as having a cone-shaped configuration, other similar shaped end wall configurationsV symmetrical about the axis of the pin 16 and capable of producing the desired jet forming cavities in the explosive material into which the pin is inserted may be employed if desired. The conical end Wall yconiiguration is preferred, however, since the pointed ends 'ofthe conical structures facilitate insertion of the ends Vof the pin into the explosive car- 4 tridges. In any case and as statedy above, thc purpose of providing the shaped end Walls 16a and 16h to define jet forming cavities in the explosive material into which the pin is inserted, is to permit the well known Munroe Effect, i. e., directionalized explosive effect, to be obtained.

Specifically, each alternate jet forming cavity thus produced in the explosive charge 1d acts to redistribute and concentrate the explosive energy of the portion of the explosive material nearest the cavity into an explosive ict. Thus. if thc charge 10 is initially detonated at the top of the charge, as by means of an electrically energized detonating cap located at the top of the charge 10, the` cavities produced by the pin end walls 16a, as shown in jet the Fig. l of the drawings, are effective to produce the sired expiosive jets. In this case, the intervening forming cavities produced by the pin ends 16h in explosive column perform no useful function. On the other hand, if the charge 1i) is initially detonated at thc bottom of the charge, the cavities formed by the pin end walls 16h are effective to produce the desired explosive iets and. the cavities formed by the pin end walls 16a are not effective. In other words only the cavity produced in the explosive colu-mn by the end of each pin 16 which is nearest the point of initial detonation of the column is eective to produce the desired explosive jet eiect. However, by using identical end wall structures at both ends of the pin 16, the desired jet effect is obtained in use, regardless of which end of each pin is inserted into a given cartridge in the column. Thus the pin is completely reversible.

Referring again to Fig. 2 of the drawings, as an explosive jet is formed at the upper end, for example, of the pin 16 within the stand-off chamber defined by the cylindrical pin body portion 20, it is transmitted through this chamber, disintegrates the end walls 16h and detonates the explosive material in which the end walls 15b are disposed. Since the chamber within the pin 16 is completely enclosed, no mud, tamping fluid or other foreign substance can enter this chamber to interfere with transmission of the explosive jet from one of the two cartridges which the pin connects to the other cartridge. As a consequence, any fluid or mud filled space which may'exist between the connected cartridges or any misalignment of the cartridges in the shot hole cannot interfere with the transfer of detonation from Vone of the two connected cartridges to the other. Thus by using the present improved pins, all that is required to obtain complete detonation of all of the cartridges in a long columnar charge is that the ends of the pins be firmly imbedded in the explosive material 0f the cartridges which they respectively connect. Moreover, by employing the jet forming connecting pins 16 to interconnect the cartridges 12 in a column 10, the overall detonating time of the column is substantially decreased. Thus, the detonating jet is formed at the active end of each pin 16 and is transmitted through the stand-off chamber of the hollow pin well into the explosive material of the cartridge into which the non-active end of the pin projects, thereby to initiate detonation of this material, well before all of the explosive material of the cartridge into which the active end of the pin projects is all detonated. The result is a speeding up of the detonation of the entire explosive column 10.

In the modified embodiment of the invention illustrated in Figs. 4 and 5 of the drawings, the cartridges 12, in addition to being interconnected by the present improved pins 16, are also sleeve connected by means of sleeves 25. As indicated above, the `sleeve type of cartridge coupling is very well known to those skilled in the art. In most applications, the sleeve coupling can be omitted when the present improved pins 16 are used to interconnect Vthe cartridges 12. The connecting and jet producing pins 16 are` identical with the pins illustrated in Figs. 1 and 2 of the drawings, except that long sharp Y spiral threads 24 are provided externally of'each pinV along the cylindrical wall thereof to 'permit threadingV of the pin ends into the adjacent ends of two explosiveY cartridges 12 arranged in end-to-end relationship. The

illustrated threaded pin arrangement is' particularly well Y adapted for usevin conjunction with explosive cartridges made up of the firmer types of explosives, such as those Vused in seismic survey operations.

If desired, the topV sitivity booster charges 26 are, ofV courseembeddedlin andlbottom end walls of each explosive cartridge conf Y tainer maybe provided with inwardly extending wellsV orV chambers, which are formed integrally with the containers and walls and are internally threaded to receive the external threads24k of the pins 16, and thereby to facilitate interconnection of the cartridges. Such. an arrangement will completely obviate any necessity for 'f pre-punching thecontainer `end wallsin order'to start insertion of the ends of the pins intoV the cartridges 12.v In Fig. of the drawings there is also illustrated one method of fabricating the pins, regardless of'whether vthe serrated structure shown in'Figs. 1 and 2 or the externally threaded structure illustrated in Figs. 4 and 5 is employed. The method of fabrication there shown is yportion of'each'pin may be formed of one piece and the conical end .parts Y16a and 16bV may be separately formed. In such case, the conical end parts 16a and 16h may be Welded tothe ends of the one piece metal pin to complete the structure;

In accordance with another important feature of the present invention, each of the pins 16 may be provided with a high sensitivity booster charge of explosive matey rial internally thereof at each' end thereof, in the manner illustrated in Fig. 6 of the drawings. Provision of the high sensitivity booster charges at the respective ends I vof the pins may be desirable to insure the production of the explosive jets through the pins in cases where the'pins are `used to interconnecty explosive cartridges y12, containing explosive material having very low sensitivity. More specifically, each booster charge comprises a body of high sensitivity explosive material 26 Y 'which is held in position at the end of the pin 16 by means of a cone-shaped liner 27; Each liner has an router circumference such that it forms a press t with lthe internal wall of the pin 16 when inserted thereinto.

Each liner 27 thus defines a conical jet forming cavityy :in the booster charge which it holds in position atrone tend of the pin 16, which is directed toward the oppo- `,:site end of the pin. Thus, the cavities formed in the booster charges 26 by the liners 27 face each other through the hollow pin 16,

ings is accomplished exact manner explainedV above with reference to the two: embodiments of the invention illustrated in Figs. l` to 4,k inclusive, and 7. -Incident to use of the booster charge loaded pins-16 `shown in Fig. 6 to interconnect two explosive cartridges y12 `containing low sensitivity*explosivematerial,'the high sen- Vthe explosive materiallocated 'at theadjacent ends of the` two ,connected cartridges. Accordingly, ifthe .explosive columnY comprising the two connected` cartridges Y is' detonated at a point nearest thefend116tzY ofthe booster charge loaded pin, v.the-booster charge located at this`V end of the pin is detonated incident to detonation of the lexplosive material in the cartridge' in which this 'lend i in a long columnar charge regardless. of the degree of. sensitivity'of the explosives contained kwithin `the car- As an alternative to the structure just described, the

-conical jet forming liners 27 may form a part of an elongated thin walled tube having an external diameter which closely. approximates the internal bore diameter yofthe pin 16, and having a length suchvthat it leaves VVchambers at the ends thereof within the ends of Ythe pin 16 which are of adequate size to receive the high sensitivity explosive charges 26. If the tube structure 27 at the ends thereof is inserted into thel pin halves.

f is used, the pin halves 16a-*and 16d may be provided Y with interengaging shoulder portions at their ends 16e l and 16JC which are equipped with matching threads to AAs will be understood, the cartridge connecting func- Y tion of the pin structure illustrated in Fig. 6 of the drawof the pin is embedded, topproduce a very high Velocity..

explosive jet whichis transmitted through the` hollow pin todetonate` tl'ie'highV sensitivity booster` charge 26 natingrthe low sensitivity explosive material of the cartridgein which .the end '16b' of the pin is embedded..

Thus the Fig. 6 embodiment ofthe invention'positively insuresfull and complete detonation of all cartridges tridges.

It will be apparent to those skilled in the art that the' present. invention is not limited to the particular con# structons shown, but that changes and modifications may be madewithout departing from the spirit and scopeof the present invention. Itis aimed in the appended claim to cover all such changes ,and modifications.

What is claimed as new and desired to be secured by' ing structure shaped to define a jet forming cavity 'inV the explosive material in one of the two connected cartridges for producing an explosive jet which is directed'Y away from said detonation point from one ofthe two connected cartridges into the other of the twoconnected cartridges. l

2. A hollow pin for securing together two adjacent Vexplosive cartridges in a column of explosive cartridges, comprising end walls disposedat at least one endV of said pin for defining a cone-shaped jet forming cavity/.in the explosive material of the cartridge into which said end walls are inserted, and a hollow body portion defining a stand-oit chamber in which the explosive jet may form yand throughwhich the explosive jet is transmitted to the explosive material of the cartridge into which the other end of the pin is inserted, said hollow body Vportion being provided with external projections engageable with p portions of the two adjacent cartridges curing said pin to the two cartridges.

3. An explosive charge comprising a pair of explosive cartridges each containing explosive material and arto assist Ain serangedin end-to-end relationship, and securing means j Y for securing said cartridges together in end` to end relationship, said securing means including a structural securing means also including a structural element ex- Y' tending into the explosive material in the other of said Jcartridges and defining another jet forming cavity directed toward said one cartridge.

4. The explosive charge defined by claim 1 wherein said pin is provided withY external projections engageable with the explosive material in each of the connected cartridges to assist in securing the pin to the two cartridges. Y

5. The explosive charge defined by claim 1 wherein the cavity defined -by 'said pin is cone-shaped,

6. The structure defined by claim 3 wherein said securing means includes opposite ends respectively extending into said cartridges and wherein said securing means is provided with an explosive charge at one end together with means defining a jet vforming cavity holding said explosive charge in position and facing the opposite end of the securing means.

7. The structure defined by claim '3 wherein said securing means includes opposite ends respectively extending into said cartridges and wherein said securing means is provided with explosive charges at its respective ends and with means defining jet forming cavities adjacent the explosive charges, which cavities face toward each other through the securing means.

8. The structure defined by claim 1 wherein said pin is provided with an explosive charge at one end together with means defining a jet forming cavity holding said explosive charge in position and facing the opposite end of the pin.

9. The structure defined by claim 1 wherein said pin is provided with explosive charges at its respective ends and wherein the explosive charges are retained within the pin by means defining jet forming cavities facing toward each other through the pin.

10. A hollow pin for securing together two adjacent cartridges in a column of explosive cartridges, said pin comprising a closed end portion at one end of said pin shaped to define a jet forming cavity, structure closing the otherV end of said pin, a hollow body portion formed integrally with said structure and said end portion and defining a stand-off chamber, an explosive charge at one end of said pin, and means for holding said explosive charge in position at said one end of the pin and for defining a jet Vforming cavity facing the opposite end of the pin.

ll. A hollow pin for securing together two adjacent cartridges in a column of explosive cartridges, said pin comprising a closed end portion at one end of said pin shaped to define a jet forming cavity, structure closing the other end of said pin, a hollow body portion formed integrally with said structure and said end portion and defining a hollow stand-0E chamber, explosive charges at the respective ends of the pin, and means for holding the explosive charges within the pin and for defining jet forming cavities facing toward each other through the pin.

References Cited in the file of this patent UNITED STATES PATENTS 2,377,151 Huber May 29, 1945 2,581,032 Landsman Ian. l, 1952 2,601,522 Heiland et a1. June 24, 1952 2,683,414 Klotz July 13, 1954 2,766,690 Lebourg Oct. 16, 1956 FOREIGN PATENTS 633,528 Great Britain Dec. 19, 1949. 851,474 Germany Oct. 6, 1952 475,997 Italy Nov. 25, 1952 GTHER REFERENCES VCorning Glass display, published in the Saturday Evening vPost, November l2, 1949, page 77.

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