Firedamp-safe method for stud driving cartridges
First Claim
1. In a process for driving a stud in a coal mine having a firedamp atmosphere which comprises disposing a stud driving machine in said firedamp atmosphere while in said coal mine, said stud driving machine comprising a cartridge chamber containing a propellant cartridge, said cartridge chamber in facing relationship to a piston or plunger itself in driving relationship at one one end with a stud to be driven in said coal mine, and firing said propellant, the improvement wherein said propellant cartridge consists essentially of a stud driving propellant, said propellant cartridge being coated with a coating material selected from the group consisting of a polymer, an amide of a C2-4 dicarboxylic acid and ammonium oxalate, said polymer in turn being selected from the group consisting of a polyacetal, a polyformal, a polyacrylate and a polymethacrylate, which coating material upon ignition of said propellant, disintegrates, said coating being present on said propellant cartridge in an amount of 15 to 30 percent by weight based on the weight of said propellant cartridge, said stud driving propellant comprising nitrocellulose, whereby said propellant is firedamp-safe.
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Accused Products
Abstract
A firedamp-safe propellant charge comprising a pyrotechnical gas-yielding propellant, said propellant coated with a polymer and/or amides of C2 -C4 dicarboxylic acids and/or ammonium oxalate, which composition, upon ignition of the propellant, disintegrates into radicals, said coating being present on said popellant in an amount of 15 to 30 weight percent based upon the weight of said propellant charge.
12 Citations
17 Claims
- 1. In a process for driving a stud in a coal mine having a firedamp atmosphere which comprises disposing a stud driving machine in said firedamp atmosphere while in said coal mine, said stud driving machine comprising a cartridge chamber containing a propellant cartridge, said cartridge chamber in facing relationship to a piston or plunger itself in driving relationship at one one end with a stud to be driven in said coal mine, and firing said propellant, the improvement wherein said propellant cartridge consists essentially of a stud driving propellant, said propellant cartridge being coated with a coating material selected from the group consisting of a polymer, an amide of a C2-4 dicarboxylic acid and ammonium oxalate, said polymer in turn being selected from the group consisting of a polyacetal, a polyformal, a polyacrylate and a polymethacrylate, which coating material upon ignition of said propellant, disintegrates, said coating being present on said propellant cartridge in an amount of 15 to 30 percent by weight based on the weight of said propellant cartridge, said stud driving propellant comprising nitrocellulose, whereby said propellant is firedamp-safe.
- 10. In a process for driving a stud in a coal mine underground which comprises disposing a stud driving machine in said coal mine underground, said stud driving machine comprising a cartridge chamber containing a propellant cartridge, said cartridge chamber in facing relationship to a piston or plunger itself in driving relationship at one end with a stud to be driven in said coal mine, and firing said propellant, the improvement wherein said propellant cartridge consists essentially of a stud driving propellant, said propellant cartridge being coated with a coating material selected from the group consisting of a polymer, an amide of a C2-4 dicarboxylic acid and ammonium oxalate, said polymer in turn being selected from the group consisting of a polyacetal, a polyformal, a polyacrylate and a polymethacrylate, which coating material upon ignition of said propellant, disintegrates, said coating being present on said propellant cartridge in an amount of 15 to 30 percent by weight based on the weight of said propellant cartridge, said stud driving propellant comprising nitrocellulose, whereby said propellant is firedamp-safe.
Specification