IMPROVEMENTS IN TOOLS OR IM- PLEMENTS TO BE USED FOR BORING OR CUTTING ROCK OR OTHER HARD SUBSTANCES FOR THE PURPOSE OF BLASTING
Year: 1853

page_text: LETTERS PATENT to Henry Kraut, of Zürich, in Switzerland,
Engineer, for the Invention of "IMPROVEMENTS IN TOOLS OR IM-
PLEMENTS TO BE USED FOR BORING OR CUTTING ROCK OR OTHER
HARD SUBSTANCES FOR THE PURPOSE OF BLASTING."
Sealed the 15th March 1854, and dated the 15th September 1853.
PROVISIONAL SPECIFICATION left by the said Henry Kraut at
the Office of the Commissioners of Patents, with his Petition, on
the 15th September 1853.
I, HENRY KRAUT, of Zurich, in Switzerland, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN TOOLS
OR IMPLEMENTS TO BE USED FOR BORING OR CUTTING ROCK OR OTHER HARD
SUBSTANCES FOR THE PURPOSE OF BLASTING" to be as follows:-
The said tool or implenient is used for cutting out a chamber or
receiver for the gunpowder or other explosive agent at the bottom of
the hole or bore made by the drift or borer commonly used for blasting.
It consists of a round bar of iron or steel fitted at its lower end with a
groove or recess for receiving a cutting chisel or blade which projects
in part over the said bar. The bar is tapered off on the side opposite
to the groove or recess so as to form an inclined plane, which will,
when the bar is acted upon by the, hammer, cause the chisel or blade
to advance and cut into the rock.

page_text: In using the above-described tool or implement for blasting, the
rock or other substance will not only be broken or loosened more
effectually, but it will also raise or lift such substance in the direction
of the bore.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Kraut in the Great Seal Patent Office
on the 15th March 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
HENRY KRAUT, of Zurich, in Switzerland, Engineer, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of September, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Henry Kraut, Her special
licence that I, the said Henry Kraut, my executors, administrators,
and assigns, or such others as I, the said Henry Kraut, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN TOOLS OR
IMPLEMENTS TO BE USED FOR BORING OR CUTTING ROCK OR OTHER HARD
SUBSTANCES FOR THE PURPOSE OF BLASTING," upon the condition (amongst
others) that I, the said Henry Kraut, by an instrument in writing
under my hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent,
NOW KNOW YE, that I, the said Henry Kraut, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement:"
My Invention consists in an improved tool or borer for cutting out a

page_text: chamber at the bottom of the hole made by the common jumper:
generally used for blasting, which chamber is intended to receive the.
powder or other explosive agent.
}
Fig. 1, in the annexed Drawing represents an improved borer of
the construction I use for cutting out chambers in holes of larger
diameters, with part of the rock in section, shewing a portion of the
hole made by the common jumper as well as part of the chamber.
Fig. 2, is a ground plan of the same. Fig. 3, is an improved borer for
holes of smaller diameters, with part of the rock in section, showing a por-
tion of the hole and chamber. Fig. 4, is a section through the line-Y, Z:
In Figs. 1 and 2, A is a bar of iron, at the lower end of which a steel
blade B, is inserted into a groove C, and secured by pins or set screws D:
The lines E, indicate an enlargement of the bar to increase its strength
and to protect the set screws D. From the side opposite the cutting
edge of the blade B, the bar A and blade B are tapered off so as
to form an inclined plane a, b, of any desired angle. F, represents the
hole made by the common jumper reaching down to the dotted line G.
After the common jumper is withdrawn from the hole F, the improved
borer A, is introduced into it, and brought to act upon the rock in the
same manner as the ordinary jumper, either by means of hammers or
by the process usually called "churning," one man guiding and turn-
ing it round. It is evident that every time the borer is made to descend,
the inclined plane will force the edge of the blade B, laterally into
the rock, whilst the bottom part of the blade will to some extent cut
the rock in a vertical direction, and thus a chamber H, will be forméd
progressively in a manner similar to that indicated by the dotted lines
1, 2, 3, &c. From the time the chamber has been widened by, twice
the distance the blade B projects beyond the bar A, or thereabouts,
the continued action of the borer will increase its depth only. The
conical elevations 1', 2', 3', &c., which are formed during the process
of boring, will in some instances have to be removed with the ordinary
jumper, the loose stone and sand being scooped out from time to time
by means of the scraper in the usual way.
In the borer shewn at Fig. 3, the part B, B, is of solid steel, and
welded on to the iron rod A; it is represented as arrived at the bottom
of the chamber H. The length of the cutting edge **, in Figs. 1, and 3,

page_text: varies according to the hardness of the substance to be cut; for hard
stone the cutting edge has to be made as short as or shorter than shewn
in Fig. 3, and for soft stone it may be made as long as or longer than
in Fig. 1. In determining this length, however, the operator must be
guided by experience.
The blade B, of the borer shewn at Fig. 1, may, if preferred, be.
welded into the bar A, or the cutting end may be made entirely of steel,
as described with reference to Fig. 3.
The superiority of this method of blasting over that in ordinary use
is twofold. In the first place, it effects a great saving in time. It is
well known that three men will bore a hole of one and three quarter
inches diameter to a given depth in one third of the time required for
a 3 inch hole. And as a chamber of 3 inches diameter at the bottom
of a bore of one and three quarter inches diameter answers the same
purpose as a uniform hole of three inches diameter made by the
common jumper, it is evident that, making a liberal allowance for
the time required to form a chamber, the economy of labor must
amount to at least forty or fifty per cent. And, in the second place,
it is clear that a given quantity of powder deposited in a chamber
formed as described must produce a far better effect than if it were
placed in a hole of uniform diameter.
I do not mean to confine myself to the particular shapes of the
borers shewn and described; what I claim as my Invention is, firstly,
the projecting part or blade B, of the borer, and secondly, the inclined
planc a, b, at the lower end of the borer, for the purposes herein-before
described.
In witness whereof, I, the said Henry Kraut, have hereunto set
my hand and seal, this Thirteenth day of March, in the year of
our Lord One thousand eight hundred and fifty-four.
HENRY KRAUT. (L.S.)