A CERTAIN IMPROVEMENT ON CHISELS OR INSTRU- MENTS FOR CUTTING OR DRESSING STONE AND CERTAIN OTHER SUBSTANCES
Year: 1834

page_text: ALL
SMITH, of Bradford, in the County of York, Machine Maker, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-third day of December, in the fifth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said John Smith, His especial licence, full power, sole privilege and authority,
that I, the said John Smith, my exors, admors, and assigns, or such others
as I, the said John Smith, my exors, adors, or assigns, should at any
time agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "A CERTAIN IMPROVEMENT ON CHISELS OR INSTRU-
MENTS FOR CUTTING OR DRESSING STONE AND CERTAIN OTHER SUBSTANCES;" in
which said Letters Patent is contained a proviso that I, the said John
Smith, shall cause a particular description of the nature of my said Inven-
tion, and in what manner the same is to be performed, to be inrolled in
His said Majesty's High Court of Chancery within two calendar months next.
and immediately after the date of the said in part recited Letters Patent, as
in and by the same, reference being thereunto had, will more fully and at
large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Smith, do hereby declare the nature of my Invention, and the manner
in which the same is to be performed, are fully described and ascertained
in and by the following description thereof, reference being had to the

page_text: Drawing hereunto annexed, and to the figures and letters marked thereon (that
is to say):
In ordinary millstone chisels, and also in chisels for cutting, dressing, or
working other stone, and also for dressing cast iron, it is well known that the
cutting edges quickly become worn, and consequently constantly require
sharpening, which operation is performed by heating the same and forging such
cutting edges to the degree of sharpness required, the operation of tempering is
then to be performed; all which requires much time and judgment, and, in
places distant from a forge, become a matter of considerable consequence.
Now the object of my Invention is to use a thin plate of steel properly tempered,
which being supported on either side by cheeks, such steel plate (as it becomes
worn) being capable of movement, in order that a sufficient quantity for the
cutting edge shall project beyond the ends of the cheeks; yet such thin steel
plate, when in use, is rigidly held between the two cheeks, and prevented receding
from its work a screw, whereby the whole, when combined, will produce a
strong and highly-useful chisel, as will be hereafter more clearly described.
DESCRIPTION OF THE DRAWING.
Figure 1 represents the side view of a chisel constructed according to my
Invention.
Figure 2 is an edge view thereof.
Figure 3 represents the two cheeks, which I usually construct of iron, and
case-harden them.
Figure 4 is a flat view, and also an edge view, of the thin steel plate, which
constantly supplies a cutting edge to the chisel.
Figure 5 is a short male screw, which fits the female screw formed in the
checks of the chisel.
Figure 6 is a small screw, with a ball or knob at the top, which screws into
the upper part of the chisel when the same is intended to be used with a
mallet. And it may be desirable here to remark that, when the chisel is used
for dressing millstones, it is affixed in a wooden handle, similar to those used
for ordinary chisels.
Figure 7 is a hammer for driving the socket, and also the wedge or cotter
hereafter mentioned; and on the end of the handle is formed a key for screw-
ing up the internal screw, Figure 5, in order to press forward and support the
steel blade as it becomes worn.
Having thus generally referred to the Figure in the Drawing, the construc-
tion of the parts there shewn will be evident to any competent workman, I
will enter shortly into the manner of putting the same together, first observing
hat in each of the Figures shewn in the Drawing the same letters of reference

page_text: indicate similar parts.
a and b are the two cheeks which constitute the main
frame of the chisel. These cheeks go together by means of the mortice c and
the studds e, e, which latter enter into recesses formed in the cheek b, as will be
evident on inspecting the various Figures. The thin steel plate is next
inserted between the two cheeks a and b, the socket f is then to be placed on
the ends of the cheeks of the chisel, which, being wedge-formed, the driving
up of the socket will cause the same to bind more closely on the steel plate
between them, and hold the same rigidly, and thus prevent lateral spring.
It should be remarked that on the cheek a is formed a groove, and in the
socket are two openings, through which the wedge or cotter g is inserted
and driven, by which the whole of the parts are securely held together. The
screw, Figure 5, is to be screwed up within the female screw in order to press
against the other end of the steel plate, to assist in preventing its receding from
its work. In using a chisel so constructed the steel plate which consti-
tutes the cutting edge will only require occasionally to be rubbed or ground
on a stone in order to improve the sharpness; and as the same becomes worn
away, in order to project a further quantity beyond the end of the cheeks a, b,
it will only be necessary to remove the wedge or cotter g, and slide down the
socket, by giving it a few blows on the knob i; the screw, Figure 5, may then
be screwed up by the key on the handle of the hammer (Figure 7), which will
project a further quantity of the steel plate below the ends of the cheeks, and
such will be the case till the screw, Figure 5, arrives at the end of the female
screw, when there will require a fresh steel plate to be inserted. At each time
of projecting the steel plate the socket is again to be driven up, and the cotter
or wedge inserted, as before described.
Having thus described the nature of my Invention, and the manner of
carrying the same into effect, I would have it understood that I do not claim
any of the parts separately of which the same is composed, but I do hereby
declare that I confine my claim of Invention to the combining of the various
parts, as above described, into a chisel for cutting or dressing stone and certain
other substances, whereby I am enabled to use a thin plate of steel as the
cutting edge, which may from time to time, as it becomes worn, be projected
forward and offer fresh quantities for use, and yet, when in use, be rigidly held
between the two cheeks, and prevented receding, by the male screw, as above
described.
In witness whereof, I, the said John Smith, have hereunto set my hand
and seal, this Sixteenth day of February, in the year of our Lord
One thousand eight hundred and thirty-five.
JOHN (L.S.) SMITH.

page_text: AND BE IT REMEMBERED, that on the Sixteenth day of February, in
the year of our Lord 1835, the aforesaid John Smith came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Twenty-third day of February, in the year of our Lord
One thousand eight hundred and thirty-five.