IMPROVEMENTS IN BITS FOR BORING AND SINKING
Year: 1856

page_text: LETTERS PATENT to William Gostwyck Gard, of Calstock, in the County
of Cornwall, Engineer, for the Invention of "IMPROVEMENTS IN BITS FOR
BORING AND SINKING."
Sealed the 10th March 1857, and dated the 30th September 1856.
PROVISIONAL SPECIFICATION left by the said William Gostwyck Gard
at the Office of the Commissioners of Patents, with his Petition, on-
the 30th September 1856.
I, WILLIAM GOSTWICK GARD, of Calstock, in the County of Cornwall,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN BITS FOR BORING AND SINKING," to be as follows:-
My Invention consists of improvements in the construction of bits for boring
and sinking, for which Letters Patent for England were granted to me the
21st October 1847. The bits were there described as formed in one piece; I
now form them in two separate and distinct parts. One part is a concave bit,
with cross or other suitable cutters attached to a hollow shaft, and com-
municating interiorly and directly therewith; the other part consists of an
outer circular cutter or ring, having slots instead of holes to prevent a vacuum,
and is made of a greater inside diameter than the cutter. By this arrange-
ment I obtain the following improvements:-The edge of the circular cutter
being the part most subject to wear and tear, from constant friction against

page_text: the sides of the bore hole, is easily and cheaply enlarged from time to time by
being heated and thrown out to its full-size by a mandril, and when too much
worn for that operation it can be easily and, cheaply renewed, the slots
render the ring or circular cutter elastic, thereby greatly facilitating the with-
drawal of the borer in case a piece of iron or other hard substance should,
accidentally fall into the hole; it also prevents a tendency to stick when
boring in tough compact stratum, such as magnésiän limestone; there is also
the advantage of being able to sharpen the interior chisel on a grinding stone,
.instead of letting back the temper and sharpening with file or cold chisel, a
process detrimental to the steel. I am also enabled to give a more enlarged
area to the passages for sludge or debris to pass up into the tube or receiver.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Gostwyck Gard in the Great Seal Patent Office
the 30th March 1857.
. 1.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GOSTWYCK GARD, of Calstock, in the County of Cornwall, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of September, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Gostwyck Gard, Her special licence that I, the said
William Gostwyck Gard, my executors, administrators, and assigns, or such
others as I, the said William Gostwyck Gard, 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 BITS FOR BORING AND SINKING," upon the
condition (amongst others) that I, the said William Gostwyck Gard, my
executors or administrators, by an instrument in writing under my, or their,,or
one of their hands and seals, should particularly. describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, 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.

page_text: NOW KNOW YE; that-I, the said William Gostwyck Gard, 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 thereof, reference being had to the. Drawings- bereunto
annexed, that is to say:
My Invention consists of improvements in the construction of bits for
boring and sinking, for which Letters Patent for England were granted to me
on the 21st October 1847. The bits were there described as formed in one
piece; I now form them in two separate and distinct parts. One part is a
concave bit, with cross or other suitable cutters attached to a hollow shaft,
and communicating interiorly and directly therewith;. the other part consists
of an outer circular cuite: or ring, having slots instead of holes to prevent a
vacuum, and is made of a greater inside diameter than the cutter..
Figure 1 shews in elevation, and Figure 2 in plan, my improved bit with
the exterior ring removed; Figure 3 is a side view, and Figure 4 a plan, of
the moveable cutting ring; Figure 5 is a longitudinal section, and Figure 6 a
plan, of the bit, ring, sludge tube, and valve complete.. A is the circular bit,
having a male screw formed on its upper part which screws into a female
screw cut in the lower part of the sludge tube G. The interior C of the bit
A forms a passage for the sludge or debris that is removed by the cutters.
D is the cutting moveable ring, which is secured in its place by the part from
c to d being made conical, so that when the circular bit A is screwed into the
sludge tube it jams the upper part of the moveable ring D against the under
side of the sludge tube G. F, F, are slots formed in the moveable cutting
ring, which renders the cutter elastic, and greatly facilitates the withdrawal of
the borer in case a piece of iron or other hard substance should accidentally
fall into the hole; it also prevents a tendency to stick when boring in tough
compact stratum, such as magnesian limestone; there is also the advantage of
being able to sharpen the interior chisel on a grindstone, instead of letting
back the temper and sharpening with file or cold chisel, a process detrimental
to the steel. The edge of the circular cutter being the part most subject
to wear and tear from constant friction against the sides of the bore hole, is
casily and cheaply enlarged by being heated and thrown out to its full size on
a mandril, and when too much worn for that operation, it can be easily and
cheaply renewed, whereas in the bits formed in one piece an entirely new bit
is necessary. B is a ball valve in the sludge tube, with its seat formed in the
top of the bit to prevent the sludge returning; and E, a hole for removing
sludge from the tube.
And having now described the nature of my said Invention, and in what

page_text: manner the same is to be performed, I declare that I claim the forming of
bits for boring and sinking of two separate and distinct parts, for the. purposes.
herein-before described.
In witness whereof, I, the said William Gostwyck Gard, have hereunto
set my hand and seal, this Twelfth day of March, One thousand eight
hundred and fifty-seven.
W G. GARD. (L.S.)