AN IM- PROVED MEANS OF BLASTING ROCKS
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Jozé Luis at the Office of the
Commissioners of Patents with his Petition, on the 10th March
1860. A communication from abroad by Charles Honoré Hypolite
Lepetit, of Cherbourg, in the Empire of France.
I, JOZE LUIS, of the British and Foreign Office for Patents, No. 1,
Welbeck Street, Cavendish Square, in the County of Middlesex, Patent
Agent, do hereby declare the nature of the said Invention for "AN IM-
PROVED MEANS OF BLASTING ROCKS," (& that it has been communicated to me
from abroad by Charles Honoré Hypolite Lepetit, of Cherbourg, in the
Empire of France, to be as follows:-
My mode of proceeding consists in replacing the small holes of mines,
usually cylindrical, the size of which can only vary slightly, by mines variable
in size and depth according to the results required. According to the size of
the mass of rock to be removed the mine is placed in the most suitable
position for blasting. The spot chosen for each mine terminates in a round
hole, either vertical or sloping, made in the ordinary way by percussion with"
the bars.
I construct the mines for these reasons with what may be termed pockets,
the blasting being to cause a separation so as to render the removal of the
detached pieces easy. The small holes of mines cause a useless separation
and employ à portion of their force in waste by throwing to a distance the
detached fragments of rock. The chambered mines placed under larger
masses cannot effect a projection above the limit of separation, thus the
advantage in favour of the chambered mines is that the same quantity of
powder costs less to lodge, produces a greater force, and effects no useless
division or projection.

page_text: The tool used for chambering the mines is of extremely simple construction;
it is composed as follows:-A compresser, in which a hole is pierced, in order
to fix a stud or pivot by means of which it is guided along the groove of the
cheeks placed at each side of it, and united at their upper extremities by a
ring, in which two rests are made to fix each side the claw of the cheeks, one
being furnished with a stop soldered to it, the other with a stop screwed in
the claw of the check, so that when the instrument is taken to pieces this
stop is unscrewed, and on turning the ring slightly the two stops thus become
placed before two grooves made in it, when they can be easily removed from
the upper part of the cheeks; at the lower part of the checks a screwed hole
is made in which a tie piece is fixed at each end; it is of steel, and is screwed
in each cheek and riveted on one so as to leave free play to the blade which
receives the blow of the compresser; a groove is made on the blade so that
it may slide freely backwards and forwards on the tic piece, and also place
itself horizontally in the pocket. At the lower part of the blade a hole is
pierced to admit a bolt fixed at the lower end of an iron or steel rod, which
passes along the cheeks and in the ring, and then along the compresser. At
the upper part of the rod a weight of iron rests, so that when the compresser
strikes the upper part of the slide of the checks, the rod with its weight causes
the blade to place itself vertically, so that no difficulty is experienced in turn-
ing the blade in the hole when the blade has to be cleaned. The blades are
made of steel, and tempered to suit the hardness of the rock; they increase in
size according as the hole enlarges.
The mode of charging the mine in the water is as follows:-On the pocket
being quite clean a bladder is tied on one end of a tin cylinder, & on the other
a paper tube to prevent the water from passing. The match enters in the
middle of the tube and is attached to the tin cylinder, so that the length is
sufficient in the bladder to allow of its being lighted under the powder in
the pocket.