US2468274A

US2468274A - Explosive device

Info

Publication number: US2468274A
Application number: US547168A
Authority: US
Inventors: John E Riley
Original assignee: Hercules Powder Co
Current assignee: Hercules Powder Co
Priority date: 1944-07-29
Filing date: 1944-07-29
Publication date: 1949-04-26
Anticipated expiration: 1966-04-26

Description

EXPLOSIVE DEVICE Filed July 29, 1944 2 Sheets-Sheet 1 FIG. 3

JOHN E. RILEY INVENTOR.

ATTORNEY April 26, 1949. J; E. RILEY EXPLOSIVE DEVICE 7 Filed July 29, 1944 2 Shets-Shaet 2 JOHN-E. RILEY INVENTOR.

BY V

ATTORNEY.

. Patented 26, 1949 Q EXPLOSIVE DEVICE John E. Riley, Kenvil, N. J assignor to Hercules Powder Company, Wilmington, Del, a corporation of Delaware Application July 29,1944, Serial No. 547,168

q 3 Claims.

This invention relates to an improvement in the explosive art, and more particularly, to an improved means for priming an explosive device.

Explosives are often packed in waterproof containers, the container being made waterproof for the purpose of making possible the use of less expensive types of explosives; i. e., those containing 7 large percentages of ammonium nitrate. However, the use of these waterproof containers makes it diflicult to effectively initiate the explosive without destroying the waterproofness of the .container.

Normally, with water resistant explosives, initiation of the explosive is brought about by punching a hole through the side of the cartridge and inserting a priming device, such as a blasting cap. In the case of metallic containers, initiation is obtained through the use 'of a metal cap well. This well holds a blasting cap in such a manner that most of the initiating force is available to act upon the explosive.

Now in accordance with this invention a primed explosive cartridge may be effectively and safely initiated by a cord-like detonating means, preferably disposed in an affixed and continuous spiral manner about an explosive cartridge.

The principle of this invention may be adapted for use in producing a priming device, said device comprising a sleeve and an attached cord-like detonating means preferably disposed on the sleeve in a continuous spiral manner. This preformed priming device may be slipped over an explosive cartridge in a sleeve-like fashion and a blasting cap assembled with one end of the detonating means to produce a cartridge assembly, which when lowered into a bore hole, may be effectively exploded. A plurality of explosive cartridges may be rigidly assembled in substantially end-to-end relationship by'means of a series of the aforementioned priming devices. A single length of such a priming sleeve may also be employed for joining a. plurality of explosive cartridges into a substantially rigid assembly. Such a primed assembly has the particular advantageous feature of effecting a substantially instantaneous and simultaneous explosion of the explosive cartridges disposed throughout the assembly.

The priming device and primed explosive cartridge involving the principle of this invention are each made efficiently and economically, preferably, by spirallywinding material and a cordlike detonating means into a continuous tube. The tube may be cut into any desired length to form the required priming device or the primed explosive cartridge.

In the accompanying drawing:

Fig. 1 is an elevational view of a primed explosive cartridge in which a preferred spiral of cordlike detonating means is carried by the cartridge.

Fig. 2 is an elevational view of the priming device assembled with a, blasting cap and an explosive cartridge.

Fig. 3 is an elevational view showing (part in crosssection) the use of the priming device of this invention as a means for combining two or more explosive cartridges into a rigid explosive assembly.

Fig. 4 is an elevational view showing one embodiment for making the priming device or the primed explosive cartridge of this invention.

The .priming device of this invention may be conveniently manufactured by the use of a conventional spiral tube machine, shown in Fig. 4. A bench ill supports a rigid mandrel l2 upon which material l4 from a stock supply (not shown) is fed to form a tube or sleeve. Simultaneously material I 6 from a stock supply (not shown) and a cord-like detonating means is fed over the material M. The detonating means is disposed underneath the layer formed by the material l6. Adjustable guide elements 22 and 24 serve to maintain the materials [4 and i6, respectively, in proper alignment so that the adjacent edges of the materials will abut each other.

The cord-like detonating means I8 is fed onto the mandrel in a continuous manner so as to form a completelyprimed section. However, unprimed sections in series may be readily formed during the winding operation by feeding along with material l6 predetermined lengths of the detonating means. These unprimed sections permit cutting of the priming device or primed explosive cartridge without cutting the detonating means, and thereby decreasing somewhat hazards in actual operations.

Various embodiments of the detonating means may be useful in this invention. 'The preferred means are of a cord-like structure such as the well-known Primacord, Cordeau, etc., however, other type structures or forms may be equally as useful.

Winding and advancing of the tube thus formed on the mandrel I2 is effected by an endless belt 26 which is obliquely trained around the mandrel. The belt engages a pair of

pulleys

28 and 30 which are rotated in unison by suitable gearing associated with the cross shaft 32. Power is transmitted to the

pulleys

28 and 30 by suitable gearing associated with the drive shaft 34 which has afiixed thereto a drive-pulley 36. When the tube is advanced to a certain position, a, cutter (not shown) engages the tube and advances therewith while cutting the tube at right angles to its longitudinal axis. In this way the various priming devies and primed explosive cartridges of this invention may be produced.

In the conventional manufacture of explosive cartridges, the outer portion of the container may be provided with a, detonating means spirally disposed in supported relationship with the container in the manner shown, for example, in Fig. 4. Thus, a moistureproot explosive-containing device, as shown in Fig. 1, is made having a priming device 3, permanently attached to an explosive container i, thereby eliminating the necessity of puncturing or destroying the waterproof characteristic of the container in order to prime the cartridge.

The priming device of this invention, as shown by Fig. 2, may be conveniently slipped into operating position with an explosive cartridge 2, thereby forming in effect a primed explosive cartridge. which is properly primed without the necessity of puncturing the cartridge for the purpose of inserting a detonating means.

Where two explosive cartridges are needed in a particular operation, assembly of these cartridges may be made by using the priming device as a joining means in which two adjacent ends of the cartridge 2 are slipped into the sleeve and the priming device, thereby holding the cartridges in assembled relationship to each other. Fig.3 shows a typical section of such an assembly.

A plurality of cartridges may be assembled in this same manner by using a priming device having a greater length sleeve in which more than two cartridges may be assembled into a substantially rigid explosive column.

The priming device of Fig. 2 or the explosive cartridge of Fig. 1 may be modified to the extent of spirally disposing the'detonating means on the inside of the tube and attaching it in position in any convenient manner, for example, it may be enclosed in a recess. In this manner the detonating means is held in protected relationship to the cartridge and free from injury when the assembly is lowered into a bore h0le*in which jagged edges might be present.

The detonating means is detonated by attaching any suitable detonator, as, for example, a blasting cap 4, to one end thereof.

The priming device or the primed explosive cartridge made after the principle of this invention is preferably constructed from strips of relatively soft waterproofed material such as Wrapping paper, kraft paper, cardboard, etc. However, other materials which are not necessarily in strip fornrmay be used such as chip board, synthetic resins, etc.

In view of the foregoing remarks the object of this invention has been achieved by providing a priming device and a primed explosive cartridge in which a detonating means is spirally disposed thercabout.

What I claim and desire to protect by Letters Patent. is:

1. An explosive device comprising a plurality oi" tubular explosive cartridges disposed in substantially continuous coaxlally end-to-end relationship, and being in propagating contact with one another, and a connecting means for adja-' cent cartridges comprising a tubular sleeve and a detonating means splrallyandexteriorly disposed on said sleeve, said sleeve holding said cartridges in a substantially rigid assembly with two adjacent ends of said cartridges contained therein. 2. An explosive device comprising a plurality of tubular explosive cartridges disposed in substantially continuous coaxial end to end relationship, and being in propagating contact with one another, and a connecting means for adjacent cartridges comprising a laminated tubular sleeve and a cordlike detonating means spirally disposed in a continuous manner underneath an exterior layer thereof, said sleeve holding said cartridges in a substantially rigid assembly with two adjacent ends of said cartridges contained therein.

3. An explosive device comprising a plurality of tubular explosive cartridges disposed in substantially continuous coaxial end to end relationship, and being in propagating contact with one another, and a connecting means for adjacent cartridges comprising a laminated tubular sleeve and a cordlike detonating fuse spirally disposed in a continuous manner underneath an exterior layer of substantially the full length thereof, said sleeve holding said cartridges in a substantially rigid assembly with two adjacent ends of said cartridges contained therein.

JOHN E. RILEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 922,343 Schulman May 18, 1909 1,517,878 Wasmayr Dec. 2, 1924 2,317,354 v Bennett Apr. 2'7, 1943 2,405,909 Smith et al Aug. 13, 1946 FOREIGN PATENTS Number Country Date 8,337 Great Britain 1910