US2594780A - Explosive dump shell - Google Patents

Description

April 29, 1952 P. F. I Ewls ExPLosIvE DUMP SHELL.

Filed April 26, 1948 FIG.

INVENTOR.

PAUL F. LEWIS Wm l/zfj ATT RNEYs Patented` Apr. 29, 1952 jaars-UNITED STATES iPirlsrlr oFgFlcEj Paul F. Lewis, Tulsa., `Okla., assignor to E. I. du Pont, de Nemours &; Company, Wilmington, Del., a corporation of Delaware Application April 26,1943, serial'No. 23,303'

l This invention relates to an improved shell for dumping materials such as explosive charges in bore holesand the like, and more particularly, to a dump shell having increased loading ease, increased dumping ease, and increased capacity over prior art dump shells of equal dimensions.

U. S. Patent 2,384,534, dated September 1l, 1945, granted to Oscar E. Chenoweth and myself, disclosed a dump shell for dumping explosive charges having a flexibly linked combination of elements inseparably secured together for operative purposes so as to prevent leakage and the loss of parts, and which at the same time per mitted charging, discharging and recharging the shells readily and with a mini-mum of diiiculty.

While-the dump shell described therein coristituted a considerable improvement over the prior art devices, it had an inherent disadvantage in that the end closure supporting member' or` cable extending through the vertical axis of the' shell acted as an obstruction to filling the shell with cartridges of conventional size and thus limited'thecapacity of the dump shell, and also limited thesize of the individual charges. In addition, the permanently attached ball-closure means tended to interfere with the free passage of the explosive charge at the point or elevation u Where charge was intended to be dumped so that a portion"V of the contents of the shell would be dumpedfafter the shell had been raised above the stratum to be shot. Obviously, this latter occurrence created a dangerous situation as it resulted in premature explosions.

In addition, .when this ball closure shell. was raised after dumping, usually at high speedthe ball remained suspended below the body of the shell. In that position, in passing through well fluids it was whipped against the well bore and thereby damaged resulting in leakiness and the need for frequent replacement.

It is, therefore, an object of the present invention to provide a safer, more economical dump shell which will release its contents where desired with greater certainty. A further object of the present invention is to provide a dump shell having increased capacity per unit of shell volume. A still further object of the present invention is to provide a dump shell having greater ease of loading. A further object of the present invention is to provide a dump shell particularly suited for depositing explosive charges in bore holes. Additional objects will become apparent as this invention is further described.

These objects are accomplished by the following invention, one embodiment of which is illus- 4 Claims. (Cl. 102-22) trated in the accompanying drawings in which Figure l is a view showing the loaded shell being lowered in a vertical bore hole; Figure 2 is a view of the same shell after the bottom of the bore hole has been reached and the shell partially raised again; Figure 3 is an enlargement of the end closure element in the engaged position; Figure 4 is a view of the positions of the releasing mechanism with the yoke -at a lower suspension point; and Figure 5 is a View of the latch jack used in the illustrated embodiment of the invention.

In the drawing, I is the shell or casing for holding the explosive charge; 2 is the closure element at the discharge end of the shell I; 3 is a bail or bracket attached to the upper end of the shell I 4 is a support for the yoke assemblyconsisting of the yoke 5, spindles 6, spindle guides 1, and springs Flexible stranded wire airplane tiller rope members 9 connect the latch jacks I0 to the yoke 5. The latch jacks I0 are adapted to fit in the recesses I I of closure element 2.and are retained in that position by the shoe ring I2 when the yoke is at an upper suspensionj point. The 4yoke assembly is releasably held at an upper suspension point by the hook I3, which is pivotly connected to the chain swivel I4, the lowering cable (not shown) being also connected 'to the swivel I4. I5 is the well wall, I6 the explosive charge, and I'I is the drop link attached tothe yoke 5.

In operation. ythe embodiment illustrated herein is used in the following manner. Theshell assembly is suspended. .on the lowering cable with the drop link I1 disengaged from the hook I3. The release mechanism is then pulled downward to the position shown in Figure 4, and the closure element 2 is placed in position so that the latch jacks lll are engaged with the recesses II. The latch jacks IB are held in place while the springs 8 are allowed to raise the assembly. The hook I3 is then engaged with the drop link Il, and the desired amount of explosive I6 is loaded into the shell I at the upper end of the shell. After loading, the shell is lowered into the bore hole I5, until it reaches the bottom, as will be indicated by change in tension on the lowering cable and by meter readings. By slackening the lowering cable sufliciently, the hook I3 descends, thereby pushing drop link I1 out of the notch into the position shown in Figure 2. When tension is restored on the lowering cable, the weight of the charge I6 overcomes the tension of springs 8, thereby causing the latch jacks Ill to extend below the shoe ring I2. Without the inward pressure of the shoe ring, the latch jacks spread, allowing the closure element to be detached. The springs 8 draw the yoke assembly to the upper suspension point drawing latch jacks I into the shell and protecting them from damage in ascent, and as the shell assembly is raised, the explosive charge I6 remains on the bottom .of the boreliole'or at any desired stratum level in' the well.

It is obvious that the number of flexible members maybe greater than 2, or that the spindles' v v be" any of the explosive compositions known to the art of oil, gaa, water well, submarine or other typesv of sub-surface shooting. The closure' element maybe machined to a leak proof t, or provided with gaskets if liquid or semiliquid materials areto be used. WhereY metall'ic`debris in the bore hole is objectionable, the

`ciosure.element may be made ofsome frangible non-metallic material such as glass, Bakelite, plastics,- resins', ete. Similarly, the ilexible members connecting the ycke and the latch jacks Hn'eefi not' `be any particular type of nbre or wire "rp'e-or cable, any type o'f linkage of suitable tensilestrength suitable. y

Al-tSWi'll be se'en from the forms illustrated by 'tlfie" drawings that the improved closurel means cper tes readily and quickly to permit easy charging and discharging, and at the same time fo'rms a snug, safe closure' for the shell. There no chance, for solid materials" to be-come wedged between the end closure and' theA shell rfthe' well bore, and thereby' be partially raised efe'becoming dislodged. By the elimination cf a central exibie member, the charge carrying portion of the shell is freed of an obstruction which prevented loading of the shell body to full capacity.

From the foregoing, it will be apparent' that' I have provided a dump shell which is adapted for' wide usage in this art with a higher degree ofs'aiety, and which. when lowered into a well.

4 releases its charge of material positively and without the disadvantages of prior devices intended for similar purposes.

Having thus described this invention, I intend that my invention be limited only according to the' following patent claims.

I claim:

1; A dump shell for depositing Aexplosive charges aty the bottomy of a vertical bore hole by means of a lowering cable under tension comprising a shell or casing for containing the explosive charge, a fully detachable closure element containing latch jack recesses for the discharge end of said. shell, and tension-responsive mechanism mounted in a bail attached to the upper end of said shell, said tension-responsive mechanism comprising a hook pivotly connected to the lowering cable, a drop link adapted to be releasably engaged by said hook, a. yoke secured to said drop link, yoke guiding means attached to the inside of said shell, a plurality of separated exible members* suspended from said yoke. adjacent to the inner periphery of said shell, said members terminating in latch jacks adapted to engage said closure element,v whereby said closure element is held in position by the wedging of the latch jacks into the latch jack recesses in said element by the lower end of the shell while the yoke is at an upper suspension POH.

2. A dump shell as claimed in claim 1, wherein spring suspension means are interposed between the yoke guiding means and the yoke. said spring suspensicn means having sufcient strength to support only the yoke, the-flexible members andthe closure element.

3. A dump shell as claimed in claim 1, wherein the flexible members are made of steel airplane tille-r rope.

Il. A dump shell as claimed in claim 1, wherein two flexible' membersl are used.

PAUL F. LEvVIs. Y

UNITED STATES PATENTS Number Name Date 1,450,485 Cousins Apr. 3, 1923 1,928,485 Gilbert Sept. 26, 1933 2,365,798 Blair et al. Dec: 26, 1944 2.384.534 Chen'cweth et al. Sept. 11, 1945

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