摘要 |
A reciprocating ram or hammer is disclosed for driving flat nails in mines without danger of creating sparks that might ignite inflammable gases that would cause an explosion. The hammer comprises a cylindrical tube in which a ram is reciprocated to strike an anvil or drive pin which pushes against a flat nail by overcoming the resistance of a helical spring in the tube. As the nail is being driven, it is held at the end of the hammer by a permanent magnet. Such flat nails are commonly driven overhead for suspending lines.
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