US2250056A - Casing perforating gun - Google Patents

Description

F. l. ALEXANDER CASING PERFORATING vGUN July 22, 1941.

Filed NOV. 3, 1959 v Patented July z2, 1941 s PATENT OFFICE cAsING PERFORMING GUN Ford I. Alexander, Whittier, Calif.

-Application November 3, 1939, Serial No. 302,681

19 Claims.

'I'his invention relates generally to perforating guns for well casing and more particularly to improvements in the shooting barrel and explosive chamber in casing perforating guns. 'I'he present invention may be considered as dealing in most of its aspects with improvements in that type of casing perforating gun in which there is provided a number of chamber blocks, usually at III. This gun body is formed in its side with a plurality (but one being illustrated in Fig. 1) of vertically spaced horizontal bores or sockets II, each met by a reduced counterbore I2 extending inwardly from the opposite side of theV gun body, the two bores being joined by an annular shoulder I3 which is here shown as beveled or conical. The forward end of bore II is screwthreaded, as

indicated at I4.

of barrel form, mounted in lateral sockets or recesses in an elongated gun body, each such block or barrel containing or housing an explosion chamber and a shooting bore.1

A general object of the invention may be stated to be the provision of an improved barrel oi' substantially increased strength and durability.

A further object of the invention is to provide a barrel construction having an explosion chamber so designed that increased iiring power is developed. Y

.A further object of the invention is to provide a form of barrel having a shooting bore of maximum length. l

A still further object of the invention is the provision of a barrel in which access to the explosion chamber is readily gained and in which such access is not rendered more dimcult by repeated firing.

A still further object of the invention is to provide improved means for sealing the explosion chamber against external liquid pressure.

It is also an object of the invention to provide a novel means for mounting the gun barrel within the elongated gun body, vthe mounting being such as to relieve the usual threaded connection between barrel and body of stress and strain during firing of the gun.

Further objects, features and advantages of my invention will appear in the course of the following detailed description of a present preferred embodiment thereof, reference for this purpose being had to the accompanying drawing in which:

Fig. 1 shows a portion of a gun body, with parts broken away to show the gun barrel of the present ,d invention in longitudinal vertical section;

Fig. 2 is an enlarged detail taken from Fig. 1;

Fig. 3 is a detail of a sealing cup;

Fig. 4 is a detail taken as indicated by line 4-4 of Fig. 1; and

Fig. 5 is a modication showing a cartridge adapted for use within the barrel of the present invention.

A portion ofthe elongated gun body, preferably cylindrical in external form, is designated 'I'he block or barrel, designated generally by numeral I5, has a preferably: cylindrical body portion I6 of such a diameter as to slide freely within bore lI, the body being formed at its forward end with screwthreads II adapted to cooperate with threads I4, and with a hexagonal projection I8 by which it may be engaged with a wrench for `thepurpose of screwing it in or out of the gun body. 'Ihe rearward end portion I9 of the barrel is reduced to such a diameter as will be received freely within reduced body bore I2, and the gunv is formed with a beveled shoulder 20 adapted to seat against the afore mentioned beveled body shoulder I3. Screwthreads I4 and I'I are designed to be suflicientlyloose fitting that no substantial strain is placed thereon when the gun is fired, the reaction being received principally by body shoulder I3.

'Ihe barrel I5 is of'comparatively large diameter, and is therefore relatively heavy. This is of advantage not only in providing a large amount of stockaround the shooting bore, there-4 by reducing or eliminating the common tendency of the barrel to crack or split, but' also reduces the kick-back of the barrel against the elongated gun body I0. The loose threaded connection between the barrel and the gun body serves to position the barrel against body shoulder I3, and while the majority. of the reactiondue to the explosion is absorbed,w by reason of the comparatively large mass of the barrel, what kickback does occur is borne principally by shoulder I3. As stated, however, the larger share of the reaction due to the explosion is absorbed by/ reason of the large mass of the barrel. and the gun body may therefore be relatively light, serving principally simply as a carrier for the barrels.

The drawing shows a construction suitable for a gun designed for relatively small diameter casing. With larger casing, the diameter of body I0 and the length of barrel I5 can of course be increased, the increase in barrel length being preferably in the portion in which the shooting bore is contained, so as to provide a shooting bore of maximum possible length, it being of course understood that the longer the shooting bore, the greater is the ilring power of the gun.

On the other hand, since, as pointed out above,

from hanging up on the casing during Vertical travel therein.

Barrel I5 is provided with an axial shooting bore 25,-within which is positioned the usual projectile 26. 'Ihis bore is preferably formed directly in the stock constituting the barrel I5,y

rather than in a small insert barrel, .as in a common type of prior practice, this preferred construction being of such increased strength that barrel splitting is entirely eliminated. An enlarged counterbore 21 is drilled inwardly from the outer end of the barrel, forming an annular seating shoulder 28. A flexible cup 29, preferably oi' soft rubber, is seated on shoulder 28, its sides fitting snugly within counterbore 21, and a frangible disk 30 of a diameter somewhat larger than that of shooting bore 25 is pressed inside the cup and seated against the bottom thereof, the bottom being supported by shoulder 28.

The lip or side of the cup is tapered, as indicated at 29', so that the pressure of the external liquid will press the side walls of the cup into tight sealing engagement with the surface of counterbore 21. The pressure fluid also acts against disk 30, pressing the latter tightly against the bottom of the cup and thus pressing the cup into tight sealing engagement with seatingv shoulder 28. 'I'he higher the external liquid pressure, the tighter is the tapered edge or lip of the cup pressed against surface 21, and therefore the tighter is the liquid seal. It will be understood that the frangible disk 30, while of suflicient strength to withstand the external liquid pressure, is easily punctured by the projectile 28 when the gun is fired.

Extending inwardly into the rearward end of barrel I5, in coaxial relationship with shooting bore 25, is a screw'threaded socket 35 adapted to receive a screwthreaded breech plug 36, while extending inwardly from the inner end of socket 35 is an explosion chamber bore 31, of a diameter somewhat less than that of socket 35, yet greater than that of shooting bore 25, the inner end of bore 31 meeting bore 25. An annular seating vshoulder 38 is formed at the juncture of socket` 35 with explosion chamber bore 31, while a conical seating surface or shoulder 39 is formed at the juncture of explosion chamber bore 31 with shooting bore 25. External leakage pressure which might otherwise leak to the explosion chamber around plug 36 is sealed off by a sealing washer 40, preferably of lead, seated against shoulder 38 and tightly engaged by the inner end of breech plug 36. A conical sealing disk 42, complementary to conical seating surface 39, is seated on the latter, and is preferably attached to the rearward end of projectile 26, as by spot welding.

'Ihe powder charge is preferably in the form of a compressed powder pellet 45 placed inside chamber 31 immediately to the rear of disk 42. To the rear of this powder pellet 45 I preferably place a soft metal expansive cup 46, formed of sharp edge 46a, for a purpose which will appear later.

The inner end of breech plug 36 is formed with a socket or recess 50 for an electrically fired fuse 5I, the fuse being provided with an electrical conductor 52 which extends outwardly through` plug 36 via a central duct 53 leading from the bottom of recess 5| through the outer end of the plug. Fuse 5I may be of a type grounded to the plug 36 in which it is seated. This fuse is preferably of a match-head type, such as manufactured by the Atlas Powder Co., and projects a flame from its forward end when 'heated by pas'- sage' of an electrical current. Such fuses are known and will require no detailed description herein.

The outer or rearward end of breech plug 36 is formed with a hexagonal projection 55 adapted for convenient engagement by a wrench, and this projection 55 has an annular recess 56 formed coaxially with duct 53, said recess being adapted to receive any suitable packing means for the fuse conductor, one preferred form of which is illustrated in the drawing at 51. Hexagonal projection 55 is provided with a number of notches 58 adapted to receive the fuse conductor 52. After the breech plug has been screwed home, the fuse conductor 52 is placed in the notch 58 closest to the extremity of an electrical conductor 59, the latter being arranged on the gun in any appropriate manner. Electrical connection is made between conductors 52 and 69, as at 60. It will be understood that the conductor 59 is part of a cable leading from the electrical control or firing system, not shown, and that any arrangement of such cable and its separate conductors on or within the gun body may be employed as desired. I here show a cable 62 positioned within a recess or groove 63 extending downwardly along the side of the gun body, the conductor 59 being led oft via an angular passageway 64 to a point just above the breech plug 36, the connection between conductor 59 and fuse wire 52 being made as previously explained.

The preferred fuse wire sealing means illustrated at 51 (see Fig. 2) comprises a flexible cup 66, preferably of rubber, seated within recess 56 and formed with a central mound 61 having a central aperture 68 adapted to lit snugly about fuse wire 52. A disk 68 having a central aperture 69 adapted to pass a conductor 52 is seated inside cup 66, and compresses mound 61 tightly about wire 52, thereby forming a pressure-tight seal.

It will be seen that the cup member 46 is positioned between fuse 5I and powder charge 45. 'I'he base of this cup member is formed with a small central aperture 10, adapted to pass the re from the fuse when the fuse is set off. Thus, when the conductor 59 is connected-through a battery to a ground on the gun body, the fuse 5I is fired, the flame passing through aperture 10 and igniting powder charge 45. The small aperture 10 confines the flame to a small diameter jet, the flame thus being more concentrated and more forcefully directed than if the confining aperture 16 were not employed, with the result that '2,250,056' powder charge 45 is, ignited lwith increased rapidity.. The normal llame from a fuse of the type illustrated results fin la comparatively slow burning o1' the powder'charge; the jetted flame from the aperture 10, on the other hand, heats the powder charge much more rapidly andresults in a much more rapid explosion of the charge, thus buildingup very high explosive pres-l sure within the explosion chamber'before the its maximum before the projectile leaves the gun.

The result is, of course, to impart to the projectile very greatly increased muzzle velocity.

As the explosive pressure is built up, the disk 42 is seated tightly, by this pressure, on the conical seat 39, thus sealing against loss of pressure until the pressure is suiiicient to rupture the disk 42. The conical disk 42 pressed against seat 39 acts as a valve, sealing tightly against loss of pressure. 'I'hese described provisions result in the explosive pressure being built up to substantially increased values before the disk 42 is ruptured and the projectile is discharged, with the result that much increased firing power is developed. i

'I'he explosion within chamber 37 results in expanding the' tapered sides of cup 46, thus pressing the sides of said cup into tight, pressure-sealing engagement with the walls of the explosion chamber, so that little back pressure escapes around the sides of said cup. The breech plug is suiiiciently small in diameter that the total back force transmitted through cup 46 to the inner end of the breech plug when the gun is ilred is not sufficient to place any undue strain on the breech plug threads. This is a feature of importance, since the avoidance of strain on the breech plug threads means that the threads will not become bound or deformed even after extensive service, and the plug may therefore always be easily and readily unscrewed. Attention is directed to the preferred use of powder charge in the form of a compressed powder pellet. Such a powder pellet occupies a much smaller space than a charge of loose powder, and the powder chamber may thus be of reduced size, which means increased explosive pressure when the charge is set olf.

Fig. 5 shows a modication, in which the projectile, conical sealing disk, powde charge, expansive cup and fuse are made up as an integrated cartridge. In the illustrative form of Fig. 5, the sea-ling disk 42a. to which is attached projectile 26a, is formed as a part of a shell 80 encasing the powder charge 45a and expansive cup 46a. being crimped about the expansive cup as at 8|. The fuse 82 is seated within the cup, as at 83, and has a fuse wire 84 extending through the base of the cup. The wire 84 is of course insulated from the cup, while the fuse is electrically grounded to the cup, and therefore, through shell 80, to the barrel I5 and the gun body. This cartridge as thus described is placed y within the barrel I5 of Fig. 1, the sealing washer 40 inserted, and the breech plug 36 screwed home.

Of course, the' fuse socket 50 in the end of the breech plug may in this case be eliminated.

The gun construction afforded by the present invention enables use of a barrel of relatively large size, in both/ diameter and length, for a gun body of a given diameter.

ItV will be understood the drawing and description are merely illustrative c? one practical form of the invention, and that various changes in design, structure and arrangement may be made without departing from the spirit and scope of p the invention or of theappended claims.

I claim:

1. In a barrel adapted to be mounted on a casing perforating gun body, an yinternal s ocket in the rearward end of said barrel, a shooting bore in said' barrel alined with said socket and cxtend` ing through the forward end of said barrel, and a breech plug mounted in said socket, there being an explosion chamber within said barrel between the inner end of said inner end of said shooting bore.

2. In a barrel receivable Within a lateral re cess in a casing perforating gun body, an internal screwthreaded socket in the rearward end of the barrel, a breech plug screwthreaded within said socket, an explosion chamber within said bar. rel forwardly of said breech p1ug, and a shooting A bore in said barrel extending from said explosion chamber ,through the forward end of the barrel.

3. A barrel for a casing perforating gun, comprising an externally screwthreaded barrel body, a screwthread socket in the rearward end of said body, a reduced explosion chamber bore extending inwardly in the barrel body from said socket, there being an annular seating surface at the juncture of said socket and said explosionl chamber bore, a sealing washer against said seating surface, a breech plug screwthreaded within said socket and engaging said sealing washer, and a shooting bore, of diameter less than that of the explosion chamber bore, extending from the inner end of said explosion chamber bore through the forward end of the barrel body.

4. A barrel for a casing perforating gun, comprising a barrel body having a screwthread socket in its rearward end, a breech plug screwthreaded within said socket, an explosion charnber bore extending inwardly in said body from said socket, a shooting bore extending from the inner end of said explosion chamber bore through the forward end of said barrel body, and an expansion cup disposed within the outer end portion of said explosion chamber bore, with its depression side facing toward the shooting bore, the space within said explosion chamber forwardly of said cup being adapted to `contain an explosive charge, and the sides of said eX- pansion cup being adapted to be pressed into 'sealing engagement with the explosion chamber adapted to contain an explosive charge, and the sides of said expansion cup being adapted to be pressed into sealing engagement with the explosion chamber bore when the charge within the explosion chamber is fired.

6. In a casing perforating gun, a body having a socket formed therein, a breech plug removably mounted in said socket, an explosion chamber plug and the within said body extending inwardly of said breech plug, a shooting bore in said body extending from said explosion chamber, said shooting bore being of less cross-sectional area than the explosion chamber, and there being a conical seating surface formed at the juncture of said shooting bore with said explosion chambenand a complementary conical frangible disk seated on said conical seating surface.

7. In a perforating gun, a body having a shooting bore therein, an enlarged counterbore at the forward end of said shooting bore, a ilexible sealing cup seated within said counterbore, and a pressure holding disk seated within said cup.

8. In a casing perforating gun, a body having an explosion chamber, a shooting bore extending from one end of said explosion chamber, means for positioning a fuse adjacent said chamber, and a wall between the fuse carried by said positioning means and the firing chamber having a small fire-concentrating aperture opposite said fuse.

9. In a casing perforating gun, a `body having a screwthread socket formed therein, an expiosion chamber bore extending inwardly in said body from said socket, a shooting bore extending from the inner end of said explosion chamber bore,A an expansion cup disposed within the outer end portion of said explosion chamber bore, with its depression side facing toward the shooting bore, the space within said explosion chamber forwardly of said cup being adapted to contain an explosive charge, a small aperture in the base of said cup, a breech plug screwthreaded within said socket, the inner end of said plug being adapted to support the base of said expansive cup when the charge Within the explosion chamber is fired, and a fuse-receiving recess in the end of said breech plug opposite said aperture.

10. In a casing perforating gun, the combination of a gun body having a transverse socket extending entirely therethrough frcm one side to the other, a barrel mounted within said socket and extending substantially entirely through said gun body, a screwthread socket in the rearward end of the barrel, a breech plug screwthreaded within said-socket, an explosion chamber within said barrel forwardly of said breech plug, and a shooting bore in said barrel extending from said explosion chamber through the forward end of the barrel 11. In a casing perforating gun, the combination of an elongated gun body having a transverse socket extending therethrough from one side to the other, a barrel received within said socket and extending substantially entirely through said gun body, a rearwardly facing shoulder on said barrel and a cooperating shoulder within said socket adapted to be engaged by said barrel shoulder, a screwthread socket in the rearward end of the barrel, a breech plug screwthreaded within said socket, an explosion chamber within said barrel forwardly of said breech plug, and a shooting bore in said barrel extend- .ing from said explosion chamber through the forward end of the barrel.

12. In a casing perforating gun, the combination of an elongated gun body having a transverse socket extending therethrough from one side to the other, a barrel received within said socket, a.

rearwardly facing shoulder on said barrel and a cooperating shoulder within said socket adapted to be engaged by said barrel shoulder, coacting loose fitting screwthreads on said barrel and inside said socket, a screwthread socket in the rearward end of the barrel, a breech plug screwthreaded within said socket, an explosion chamber within said barrel forwardly of said breech plug, and a shooting bore in said barrel extending from said explosion chamber through the forward end of the barrel.

13. In a casing perforating gun, the combination of an elongated gun body having a transverse socket, a barrel received within'said socket, a rearwardly facing shoulder on said barrel and a cooperating shoulder within said socket adapted to be engaged by said barrel shoulder, coacting loose tting screwthreads on said barrel and inside said socket, a screwthread socket in the rearward end of the barrel, a breech plug screwthreaded within said socket, an explosion chamber within said barrel forwardly of' said breech plug, and a shooting bore in said barrel extending from said explosion chamber through the forward end of the barrel.

14. In a barrel receivable within a lateral recess in a casing perforating gun body, an internal screwthreaded socket in the rearward end of the barrel, a breech plug screwthreaded within said socket, an explosion chamber within said barrel forwardly of said breech plug, and a shooting bore in 'said barrel, of lesser cross-sectional area than said explosion chamber, extending from said explosion chamber through the forward end of the barrel.

15. A relatively massive and thick-walled barrel for a casing perforating gun body, said barrel having an internal screwthreaded socket in its rearward end, a breech plug screwthreaded within said socket, there being an explosion chamber within said barrel forwardly of said breech plug socket, and a co-axial shoting bore in said barrel, of lesser cross-sectional area than said explosion chamber, extending from said explosion chamber through the forward end of the barrel.

16. In a casing perforating gun, the combination of a gun body having a transverse socket extending entirely therethrough from one side to the other, a barrel mounted within said socket and extending substantially entirely through said gun body, a screwthreaded-socket in the rearward end of the barrel, 'a breech plug screwthreaded within said socket, and being of sumciently small diameter to be removable from the end of the barrel through the endv portion of the transverse socket in. the gun body while the barrel is mounted in the gun body, an explosion chamber Within said barrel forwardly of said breech plug, and a shooting bore in said barrel extending from said explosion chamber through the forward end of the barrel.

17. In combination in a perforating gun, a shooting bore, an enlarged cartridge chamber at the breech end of said shooting bore, a shoulder between sai-d bore and chamber, and a cartridge embodying a shear wall adapted to be positioned adjacent said shoulder and to overlap the breech end of the shooting bore all around, a cylindrical cartridge side wall extending rearwardly from said shear wall, and a closure disk closing the rearward end of said side wall, said cartridge' between said bore and chamber, and a cartridge embodying a shear wall adapted to be positioned adjacent said shoulder and to overlap the breech end of the shooting bore all around, a cylindrical cartridge side Wall integral with and extending rearwardly from said shear Wall, and a closure disk closing the rearward endv of said side wall, said cartridge being adapted to contain an explosive charge, and said shear wall being adapted to resist shearing over the area of said shooting bore until a relatively high explosive pressure has been built up inside the cartridge.

19. In combination in a perforating gun, a shooting bore, an enlarged cartridge chamber at the breech end of said shooting bore, a shoulder 15 between vsaid bore and chamber, and a cartridge embodying a shear wall adapted to be positioned adjacent said shoulder and to overlap the breech end of the shooting bore all around, a projectile attached to said shear Wall at the center and

Images