Improvements in Tools or Bits for Boring Rocks and other Hard Substances.
Year: 1898

page_text: Date of Application, 3rd Nov., 1898
Complete Specification Left 14th Feb 1899 Accepted, 18th Mar. 1899
Date of Application, 3rd Nov., 1898
Complete Specification Left 14th Feb 1899 Accented, 18th Mar. 1899
+
PROVISIONAL SPECIFICATION.
Improvements in Tools or Bits for Boring Rocks and other Hard
Substances.
We, ROBERT THOMAS RELF, of the Firm of R. T. Relf & Son, of 12, Portland
Square, Plymouth, in the County of Devon, Contractors, and GEORGE WESTLAKE,
of 12, Portland Square aforesaid, Foreman to R. T. Relf Son, do hereby declare
the nature of this invention to be as follows:
--
This invention relates to tools or bits such as are used in percussive machines
for boring holes in rocks and similar hard substances.
A bit constructed according to our invention has the cutting end formed with
a series of radiating cutting edges and through the centre of the bit is bored a
longitudinal hole which opens above the head of the bit near the shank so that
dust or sludge below the bit can escape upwards through the hole whereby there
will be less difficulty than heretofore in getting the bit properly down to its work.
Dated the 3rd day of November 1898.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicants.
Improvements in Tools or Bits for Boring Rocks and other Hard
Substances.
We, ROBERT THOMAS RELF, of the Firm of R. T. Relf & Son, of 12, Portland
Square, Plymouth, in the County of Devon, Contractors, and GEORGE WESTLAKE,
of 12, Portland Square aforesaid, Foreman to R. T. Relf & Son, 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; -
This invention relates to tools or bits such as are used in percussive machines
for boring holes in rocks and similar hard substances.
A bit constructed according to our invention has the cutting end made cylin-
drical and formed with a series of radiating cutting edges and through the centre
of the bit is bored a longitudinal hole which opens above the head of the bit near
the shank so that dust or sludge below the bit can escape.
To enable the invention to be fully understood we will describe the same by
reference to the accompanying drawing, in which:--
Figure 1 is an elevation; and,
Figure 2 a longitudinal section of a boring bit constructed according to our
invention:
Figure 3 is an underside view of the same.

page_text: a is the cylindrical head of the bit and b is the shank; the said head as herein-
before stated is made of cylindrical shape, this shape being adopted to ensure that
the hole drilled by the bit shall be round and not more or less angular as is fre-
quently the case with holes bored with a bit of ordinary construction, whereby the
canisters or the like containing charges of dynamite or other blasting material
may be inserted into the holes without the liability of binding or sticking therein
as is frequently the case when the holes are not circular.
c is the central hole formed through the bit and which serves to allow the sludge
below the bit to escape, which otherwise would form a cushion or buffer which
would prevent the drill from properly operating. In addition to this hole we may
form grooves such as d, d in the surface of the head a, as shewn, and, in some
cases, when these grooves are made use of, the central hole may be dispensed with.
e, & are the cutting edges of the bit which as shewn are arranged to radiate from
the axis of the said bit.
Although we have illustrated our improved tool or bit as having four cutting
edges, it is to be understood that we do not restrict it to this number.
Our improved bits are very advantageously used in connection with the boring
apparatus forming the subject matter of our application for Letters Patent
No. 22879 dated 31st October 1898.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. A boring tool or bit having the cutting end made of cylindrical shape so as
to fill the hole which it bores and having a central passage or aperture through
which the sludge can escape from below the bit, substantially as described.
2. A boring tool or bit having a cylindrical cutting end and provided with
a channel or passage through which the sludge may pass, substantially as described.
3. The manufacture and use of boring tools or bits, substantially as herein before
described and illustrated in the accompanying drawing.
Dated this 13th day of February 1899
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicants.