GB664583A - Blasting initiator - Google Patents
Blasting initiatorInfo
- Publication number
- GB664583A GB664583A GB29095/49A GB2909549A GB664583A GB 664583 A GB664583 A GB 664583A GB 29095/49 A GB29095/49 A GB 29095/49A GB 2909549 A GB2909549 A GB 2909549A GB 664583 A GB664583 A GB 664583A
- Authority
- GB
- United Kingdom
- Prior art keywords
- plug
- charge
- parts
- carbon black
- wires
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B3/00—Blasting cartridges, i.e. case and explosive
- F42B3/10—Initiators therefor
- F42B3/18—Safety initiators resistant to premature firing by static electricity or stray currents
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B3/00—Blasting cartridges, i.e. case and explosive
- F42B3/10—Initiators therefor
- F42B3/103—Mounting initiator heads in initiators; Sealing-plugs
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
664,583. Blasting fuzes. DU PONT DE NEMOURS & CO., E. 1. Nov. 14, 1949. [June 11, 1949] No. 29095/49. Class 9 (i). An electric blasting cap comprises a shell closed by a rubberlike holding the leg wires, the plug being made of a composition containing sufficient carbon black for the electrical resistivity of the plug to be not more than 3 x 10<SP>4</SP> ohms per c.c. The metal shell 1 contains a base charge 2 of compressed tetryl with a primer charge 3 of compressed lead azide within a cavity in the charge 2. An ignition charge 8 of lead styphnate mixed with smokeless powder in proportion 80-20 and grained with gum arabic is superposed on the primer charge. The shell is closed by a plug 4 moulded about leg-wires 5 connected by a resistance wire 7 so that on passing a current through the wire 5 the charge 8 is ignited. The leg-wires are free from insulation for a part of the length 6 within the plug, which is a polymerised chloroprene composition containing 75 parts by weight of carbon black per 100 parts of neoprene. This composition is of sufficiently low conductivity to allow the firing current to pass through the bridge wire while the conductivity is sufficient for static discharges of the order of 10,000 volts at 0.0003 mfd capacity to be grounded to the shell. In a modification the loose ignition charge may be replaced by a bead 9 of lead styphnate surrounding the bridge wire. In this case the plug has a carbon black content of 75 parts per 100 parts of rubber to increase the conductivity. In another initiation the base charge 2 is a 50-25-25 blend of smokeless powder, a double salt of lead nitrate with a lead salt of dinitro-orthocresol and potassium chlorate. The primer charge is red lead and boron. The plug comprises 50 parts by weight of carbon black with 100 parts of rubber. As additional protection against static discharge a body of dielectric material may be placed between the exposed portion of the leg and bridge wires and the shell wall. Fig. 4 shows a sleeve 11 of dielectric material extending from a wedge-shaped extension of the plug. The dielectric material may be a solid mass almost completely enclosing the ignition bead and exposed leg wires or it may be used as a coating on the exposed leg wires and exposed part of the bridge wire. The dielectric material may be a synthetic resin composition or a sulphur-base cement. Synthetic or natural rubbers may be used for the plug and the carbon black content is preferably between 30 and 100 parts. The carbon black may be acetylene black.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US664583XA | 1949-06-11 | 1949-06-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB664583A true GB664583A (en) | 1952-01-09 |
Family
ID=22069628
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB29095/49A Expired GB664583A (en) | 1949-06-11 | 1949-11-14 | Blasting initiator |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB664583A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2685835A (en) * | 1952-07-29 | 1954-08-10 | Du Pont | Blasting initiator |
US2802421A (en) * | 1953-11-09 | 1957-08-13 | Hercules Powder Co Ltd | Static resistant electric initiator |
JPS5324380U (en) * | 1976-08-09 | 1978-03-01 | ||
DE3735405A1 (en) * | 1987-10-20 | 1989-05-11 | Dynamit Nobel Ag | IGNITION PILL |
-
1949
- 1949-11-14 GB GB29095/49A patent/GB664583A/en not_active Expired
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2685835A (en) * | 1952-07-29 | 1954-08-10 | Du Pont | Blasting initiator |
US2802421A (en) * | 1953-11-09 | 1957-08-13 | Hercules Powder Co Ltd | Static resistant electric initiator |
JPS5324380U (en) * | 1976-08-09 | 1978-03-01 | ||
JPS574095Y2 (en) * | 1976-08-09 | 1982-01-26 | ||
DE3735405A1 (en) * | 1987-10-20 | 1989-05-11 | Dynamit Nobel Ag | IGNITION PILL |
DE3735405C2 (en) * | 1987-10-20 | 1998-07-30 | Dynamit Nobel Ag | Firing pill |
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