US2377763A - Loading basket for explosive charges - Google Patents

Description

June 5, 1945. E. F. DARNELL 2,377,763

LOADING BASKET FOR EXPLOSIVE CHARGES Filed Aug. 51, 1942 I fatented June 5, 1945 UNITED STATES, PATENT- OFFICE Edward F. Darnell, San Antonio, Tex., assignor to Olive S. Petty, San Antonio, Tex.

- Application August 31, 1942, Serial No. 456,813

9 Claims.

This invention relates to loading means for explosives such as used in geophysical prospecting although obviously not limited to this particular use.

In loading elongated cartridges of explosive in deep vertical bore holes, particularly those in loose or sandy soil, difllculty has been experienced both in forcing the charge to the bottom of the hole and in then retaining it there while the loading implement is withdrawn. It is therefore an object of the present invention to provide a novel and improved form of loading implement for introducing' explosive charges into holes in loose or sandy soil.

Charges of the type referred to are universally fired by the use of electric detonators or caps and a pair of conductors must extend from the surface to the charge at the bottom of the hole. The hole is often partially filled with debris from drilling and is usually wet from the use of water to clear the drilled material as much as possible during the drilling operation. It is oftentimes dififlcult to protect the electric wires leading to the detonating' cap and to prevent the cap from being loosened from the charge during the sometimes rather strenuous efforts necessitated to force the charge past the debris to,the bottom of the hole. It is therefore a further object of the invention to provide a loading implement offering maximum protection to both the charge and the conductors or cap leads.

v The invention is primarily applicable to explosives packaged in water-tight cans, a plurality of which may be secured together in the form of a long stick, by mating threads at the tops and bot toms of the cans. In connection with such explosives, the detonator or firing cap is protected by a non-metallic shield to which the lead wires are attached. This shield is threaded into the recess in the topmost can and covers the detonator housed in a shallow well in the can beneath the shield. Since it is of advantage to be able to rotate the stick oi. explosive in order to force it down through sand, muck and the like near the bottom of the hole, it is an object of the present invention to provide a loading device having means for cooperating with the aforementioned shield to permit the latter, and hence the charge, to be rotated by the application of suitable twisting to the loading device.

A still further object of the invention consists in the provision" of a charge loading device which facilitates the entrance of sand above the charge during loading to hold the same in position upon withdrawal of the loading device and offering and showing the loading implement of the present invention in position thereon;

"Figure 2' is a transverse section on line 2-2 of Figure 1 looking in the direction of the arrows;

Figure 3 is an enlarged fragmentary elevation taken at right angles to Figure 1 and shown partially in section on line 3-3 of Figure 2; and

Figure 4 is a perspective view of the loadin implement or basket.

The holes drilled in the earth for the reception of charges to be exploded for the making of seismic records in geophysical prospecting often encounter soft, sandy or crumbly soil and although every effort is made during the drilling to remove the debris, a large quantity oftentimes finds its Way to the bottom of the hole and defies removal. To introduce the relatively large charge of explosive to the bottom of the hole through this material and by various obstructions is oftentimes exceedingly difiicult. In the most aggravated situations, casings are sometimes required but these are expensive and time-consuming to insert. Any implement which facilitates the insertion of the charge to its proper location will eliminate the need for many casings. Many of the seismic parties are making use of a form of explosive which is packed in metal cans I0 such as shown in Figure 1, having a depression in the top, the walls of which are internally threaded as at H, and also having a correspondingly threaded projection on the bottom. Any number of cans can'be combined into a long rod or stick by the simple expedient of screwing the cans together. The topmost can, which usually contains a special priming composition, has an additional depression l3 of lesser diameter extending from the bottom of the major depression to receive the electric blasting cap l4. To hold this cap in position, to protect it and to provide anchorage for the electric wires or leads l5 therefrom, which are also used openings in the ring segment 32.

to lower the charge into the hole, the protective shield IQ is mounted on top of the can.

This shield is moulded from some suitable intersecting these apertures and extending down along the sides as at 20.

In making up the shot assembly, the cap with its attached leads is passed through one of the openings is in such a manner that the cap dangles-from beneath the plug end of the shield in a position to be received in the recess 13.

' The conductors are then suitably attached to ,re a

movement of'sand, muck, and the likefto' a position above the charge to hold the same in loaded position when the loading pole and its attached basket are to be withdrawn. Even in the shield for instance by passing them together several times through the holes i8 if desired, then down along the side groove 20, separating them and'taking each a full turn about the top of the plug. Theyare then brought up again through the same side groove and are held in position by being clamped between the shield and the can when this assembly is made. The conductors are thus firmly anchored to the whole charge which can be suspended from them and lowered into the hole. One of the side grooves is left entirely clear for a purpose to be later described.

In order to permit manipulation of the charge and the forcing of the same down through muck or sand andby obstructions, a basket-like implement is provided, adapted to engage over the topmost can as shown. in Figure 1 and to be attached to a loading rod or pole such as shown at 26. The lower end of this pole is threaded as at 21 to be received in the internally threaded ferrule 28 at the upper end of the backet assembly. This ferrule is attached to a short section of square rod 29 which has welded to its lower end four quarter-inch steel rods 30. These are splayed apart and passed through arcuate portion of square section metal having a maximum diameter somewhat larger than that of the shield and a minimum diameter somewhat less than that of the shield whereby it may rest on the top thereof for forcing the charge down. The depending portions of the rod 30 only loosely engage the sides of the can sothat they can be readily withdrawn from the same when the charge is to be released at the bottom of the hole. The lower ends of the rods 30 are welded to a curved bar 34 which holds them in position.

The open side of the basket, defined by the lateral openings in the segmental elements 32 and 34 and amounting to almost 30% of the periphery, does not permit removal of the charge laterally while yet permitting the cap leads to extend directly upwardly from the shield without being threaded through any part thereof. When the basket is withdrawn, it does not tangle with the leads. To prevent the leads from becoming twisted about the rod during manipulation and to permit rotation of the cans to better force the charge by obstructions the ring 32 is provided with a depending lug 36. This is adapted to engage in a portion of the slot l9 and the upper end of the slot 20 not occupied by the cap leads to prevent relative rotation of the This is an shield and basket. Rotation of the loading rodthe presence of water and soft muck, the open basket prevents formation of a vacuum which might tend to withdraw the can withthe basket.

The' threads in the ferrule of the loading basket are the same as those used on other implements forming a part of the shooter's equipment, such as reamers, spears, and the like, used for opening or enlargingholes. By being rigidly attached to the end of the pole and chil -8 8 a considerable length of one of the cans, the basket keeps the charge aligned with the axis of the hole so that it does not tend to catch on the walls thereof. The charge is kept in place within the basket by tension applied to the cap leads in an obvious manner.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A loading basket for elongated explosive charges equipped at the top with a cap shield and lead anchor having a slot therein comprising in combination a ferrule for threaded at tachment to a loading rod, splayed rods extending from the ferrule and shaped and spaced to loosely conform to the outside of the upper end of thecharge, segmental rings connecting the rods together, the upper one being sized to engage the top of said shield to exert downward pressure thereon, and a lug on said top ring-to engage in said shield slot to prevent relative rotation of the charge and basket.

2. A leading basket for elongated explosive charges equipped at the top with a cap shield and lead anchor having a slot therein comprising in combination a ferrule for threaded attachment to a loading rod,'splayed rods extending from the ferrule and shaped and spaced to loosely conformto the outside of the upper end of the charge, upper and lower segmental rings connecting the rods together, the-lateral openings in the rings being disposed at the same side 01' the basket, the upper ring being sized to engage the top of said shield to exert downward pressure thereon, and a lug on said upper ring to engage in said shield slot to prevent relative rotation of the charge and basket, said lug being and upper portion of the charge, said basket being formed of connected rods andrings leaving large openings above and around the charge, one side of the basket being open for substantially its full length whereby it may be withdrawn from the charge without engaging the leads, means on said basket adapted to engage the top of t shield to press the same downward and inte engaging means on the shield and basket to pre-' vent relative rotation therebetween.

4. A loading basket for use with an elongated rigidly encased explosive charge capped with a detonator shield. at least as large in diameter.

as the charge and having cap wires attached thereto, comprising a rigid tubular basket of large mesh providing a loose llt over the shield and upper end of the charge, the top of the basket converging to a. ferrule providing means for attachment to a loading pole, means forming a part ofthe basket and adapted to bear on the upper surface of the shield to exert downward 'circumferentially disposed elements connecting force thereon, means on the basket to cooperate with the shield to prevent relative rotation therebetween, the basket being entirely open from the bottom to above said force exerting means for a portion of its circumference.

5. A loading basket for use with an elongated, cylindrical, rigid explosive charge having detonator cap wires issuing from the top thereof, comprising a rigid, inverted, tubular basket sized for a loose fit over the upper end of the charge, the top of the basket being of large mesh and converging to a ferrule providing for attachment to a loading pole, a fixed portion of the basket being arranged to engage the top of the charge over only a small portion of its area and remote from the said wires, the basket being entirely open for its full length for a small arcuate section of its circumference for passage of said wires when engaging or disengaging the basket and charge.

6. A loading basket for use with an elongated, cylindrical, rigid explosive charge having detonator cap wires issuing from the top thereof, comprising a rigid, inverted, tubular basket sized for a loose fit over the upper end of the charge, the top of the basket being of large mesh and converging to a ferrule providing for attachment to a loading pole, a fixed portion of the basket being arranged to engage the top of the charge over only a small portion of its area and remote from the said wires, the basket being entirely open for its full length for a small arcuate section of its circumference for passage of said wires when engaging or disengaging the basket and charge, and means on said charge and basket engageable to prevent relative rotation therebetween. v

7. A loading basket for elongated explosive charges equipped at the top with a cap shield and having detonator cap wires extending therefrom, comprising in combination a plurality of rods converging toward their upper ends to facilitate connection thereof to a loading rod and shaped and spaced to conform loosely to the outside of the upper end of the charge, and a plurality of the rods together, said elements including an upper element shaped and dimensioned to engage .the top of said shield to exert downward pressure thereon, and a lower element shaped and dimensioned to embrace loosely said charge, said elements being discontinuous at one side of said basket to afford an opening for passage of said wires when engaging or disengaging the basket and charge.

8. A loading basket for elongated explosive charges equipped at the top with a cap shield comprising in combination a plurality of rods converging at their upper ends and shaped and spaced to loosely conform to the outside of the upper end of the charge, and a plurality of circumferentially disposed elements connecting the rods together, said elements including an upper element shaped and dimensioned to engage the top of said shield to exert downward pressure thereon and being provided with means for engagement with said shield to lock the basket and shield against relative rotation about the axis of the charge, and a lower element shaped and dimensioned to embrace loosely said charge.

9. A loading basket for elongated explosive charges equipped at the top with a cap shield, comprising in combination a plurality of rods extending over a substantia1 portion of their length in such parallel spaced relation as to loosely conform to the outside of the upper end of the charge, said rods converging toward their upper ends to facilitate connection thereof to a loading rod, and a plurality of circumferentially disposed elements connecting the rods together, said elements including an upper element shaped and dimensioned to engage the top of said shield to exert downward pressure thereon, and a lower element shaped and dimensioned to embrace loosely said charge, and means acting between said basket and said charge to lock the same against relative rotation about the longitudinal axis of the charge.

EDWARD F. DARNEIL.

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