Improvements in Rock Drills for Boring Shot Holes and the like.
Year: 1892

page_text: Date of Application, 9th Feb., 1892
Complete Specification Left, 9th Nov., 1892-Accepted, 16th Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Rock Drills for Boring Shot Holes and the like.
1 VICTOR GUILLAT, Engineer, of St. Laurent in the Republic of France, do
hereby declare the nature of this invention to be as follows:-
--
This invention for improvements in rock drills for boring shot holes and the like
has for its object to form an enlarged chamber for the explosive material at the
bottom of the shot hole and consists of a bit fixed at the extremity of a head by a
rivet or screw, and of two cutters fixed in a slot in the head by a screw passing
through the head. The two cutters are opened out by means of an endless screw
fitted to the head.
Dated this 9th day of February 1892.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, Agents.
COMPLETE SPECIFICATION.
Improvements in Rock Drills for Boring Shot Holes and the like.
I, VICTOR GUILLAT, of Saint Laurent-du-Pont, (Iserè), in the Republic of
France, Machinery Manufacturer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The boring of tunnels across reefs or rocks in mines and exterior places by
mechanical means, may such be actuated by compressed air or by hand and which
apparently comes more and more in use require the ground work blasting by
explosives, the boring of shot holes on which depends the whole success of
blasting.
Very often shots are obtained which have no or insufficient effect on the rock
as the explosive charge fills the larger part of the hole; and when boring a hole of
larger diameter it is only a considerable loss of time and great expense throughout
with the hand perforator.
The apparatus which I provide permits of boring a hole of normal diameter
(0-04 to 0.05 millimetre) an enlargement constituting a chamber where is localized
the whole charge in such a manner as to produce the highest effect and assure also
a certain success of the discharge of the mine.
And in order that my invention may be more fully understood I have caused to
be appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures.
Fig. 1 is an elevation of the tool complete.
Fig. 2 a view of the cutting bit.
Fig. 3 a view of the stock.
Fig. 4 a view of the two cutters and
Fig. 5 a view of the drill.
In carrying out my invention this apparatus is composed of a cutting bit A
arranged at the extremity of the stock B in which are fixed two cutters C which
expand through the pressure exerted on the drill D with spiral cutting faces, the
whole adapted on the stock B which permits of the same acting regular.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim, is-
In rock drills for boring shot-holes and the like, an expanding cutter with two
blades C, which are opened by the drill D for boring interior chambers, which
blades C are arranged in the interior of the stock B which receives at the same
time at one of its extremities the cutter A and at the other extremity the drill D,
substantially as set forth.
Dated this 8th day of November 1892.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.