Perfectionnements dans l’application de la pression pneumatique et hydraulique au forage, au broyage, à la pulvérisation et au martelage des pierres et autres corps durs
My invention relates to an improved machine for drilling or boring rocks and other hard substances.
The said machine comprises the employment of a pneumatic cylinder fitted with a piston which is drawn toward the top of the cylinder by the action of a revolving cam or cams fixed on a shaft, which may be rotated by hand-power applied to a winch, or by gearing with any first mover. The said piston is packed by a cup-leather or otherwise, so that it becomes a perfectly air-tight partition between the portions or volumes of air on each side of it when it is rising, but permits air to pass by it in its descending stroke to compensate for any small amount of leakage which may occur. The said piston is fitted with a tubular rod, which works through a stuffing-box or leather collar in the top cover of the cylinder, or in both covers.
If in the top cover only, I provide holes in the bottom cover or lower part of the cylinder to allow a free passage for the air to the under side of the piston, that is to say, I prefer this construction; but I do not confine myself to the same, as it is obvious that my invention may be carried into practice with a vacuum on the under side and a plenum on the upper side of the piston; or the vacuum only may be used with substantially the same result. When the said piston is drawn up by the action of the revolving cam the whole of the air above it will be compressed into the space between its top side and the under side of the cylinder-cover; and as this space may bear any determined proportion to the whole contents of the stroke, it is obvious that the machine may be made to work under any required pressure, so as to utilize to the best advantage the power at command.
The application was not examined and the patent was granted on 10 September 1880 under the 1880 Patent Law. [2]
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[1] US patents No 201,017 and No 211,022
[2] LU patent No 60