摘要:
An apparatus for breaking coal or other mineral matter from a bed thereof which comprises a string filling a bore hole which can rise steeply in this bed. The string consists of alternating breaking units and connecting pipes each braking unit having a differential piston displaced solely by the action of air pressure so that breaking slots are unblocked to discharge compressed air built up in the string. The pistons are provided with check valves to permit filling of the string.
摘要:
Forming a hole between lower and upper parallel galleries formed in a mine by boring upwardly from the lower gallery a bore hole having a first length equal to a fraction of the distance between the lower and upper galleries, then casing the bore hole by thrusting upwardly at least one pipe section having a diameter sufficient to be gripped by the shrinkage of the bore hole into the bore hole. Boring upwardly after casing the first length by a further length equal to a fraction of the distance between the lower and upper galleries, then casing the newly formed further length of the bore hole by thrusting upwardly at least one further pipe section having a diameter less than the inside diameter of any pipe sections previously disposed in the bore hole and sufficient to be gripped by the shrinkage of the newly formed further length of the bore hole through the any previously disposed pipe sections into the newly formed further length of the bore hole, and then repeating the two previous steps of boring a further length and casing the newly formed further length until the upper gallery is reached.
摘要:
A method for breaking coal and other mineral matter from a bed thereof provided with a bore hole consists of the steps of applying a flushing medium to a drill bit, loosening the mineral matter upon completing the drilling by conveying the compressed air to a plurality of blow slots and sealing a mouth of the bore before loosening the mineral matter.