CERTAIN IMPROVEMENTS ON CIRCULAR SAWS FOR SAWING WOOD IN AN EASY AND EXPEDITIOUS MANNER
Year: 1808

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARC.
ISAMBARD BRUNEL, of Chelsea, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourteenth day of
March, in the forty-eighth year of His reign, give and grant unto me, the
said Marc Isambard Brunel, my exors,, admors, and assigns, His especial
licence, full power, sole priviledge and authority, that I, the said Marc
Isambard Brunell, my exors, admors, and assigns, during the term of years
therein mentioned, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "CERTAIN IMPROVEMENTS ON CIRCULAR SAWS FOR SAWING WOOD IN AN EASY
AND EXPEDITIOUS MANNER;" in which said Letters Patent there is contained
a proviso obliging me, the said Marc Isambard Brunel, by an instrument in
writing under my hand and seal, to cause a particular description of the
nature of my said Invention, and in what manner the same is to be per-
formed, to be inrolled in His Majesty's High Court of Chancery within six
calendar months after the date of the said recited Letters Patent, as in and
by the same, relation being thereunto had, may more fully and at large
appear.
NOW KNOW YE, that in compliance with the said. proviso, I, the said
Marc Isambard Brunel, do hereby declare that my said Invention is described
in manner following, that is to say:-

page_text: The Certain Improvements on Circular Saws for Sawing Wood in an Easy
and Expeditious Manner are intended to cut out thin boards or slips with as
little waste as appears practicable. In order to obtain that end a saw requires
to possess two essential qualities, viz, a very thin edge, and at the same time
a great degree of steadiness. The certain improvements above mentioned
consist in the construction of a circular saw or circular saws which aro
intended to unite both qualities, and thereby render the sawing easy and
expeditious.
The annexed Drawings shew the plan, elevation, and sections of a circular
saw or circular saws composed of one or more pieces. The saw represented
in the plan and elevations is ten feet diameter, and is composed of several
plates of steel C, C, C, C, C, C, Fig. 2, fixed to a circular frame or wheel
A, A, Fig. 2, 3, and 4. The extremity of this circular frame terminates into
a tapered rim, as is represented at full size at A, Fig. 1. The plates of steel
C, C, Fig. 2, form segments fixed by means of a circular clamp or clamps B,
Fig. 1, screwed or rivetted to the rim A. The surface of the segments, laid
as they are represented at C, Fig. 1 and 2, is of a conical form, which termi-
nates into a thin edge D, Fig. 1. This edge is cut, as a common circular
saw, into teeth, which may be set at pleasure in the usual manner. The
conical side of the plates or segments is hollowed out towards the extreme
edge, in order to render the passage of the saw easy and free from friction.
In the act of sawing, the board, or slip separated by the saw is kept off to
prevent its rubbing against the plates, see L, Fig. 1, 3, and 4, either by hand
or by the assistance of some wedge fixed to the machinery. The circular
frame on the edge of which the segments C, C, C, C, C, C, Fig. 2, are
screwed is fixed to a shaft E, Fig. 3 and 4, which is to be set in motion by such
means as may appear the most eligible. In the annexed Drawings it is
intended to be put in motion by a steam engine, and connected to it by means
of a strap revolving on a drum F, Fig. 3 and 4. The manner of using this
saw is as follows:-The log or piece of wood to be cut is laid against and
fastened to a table H, II, Fig. 2, 3, and 4. The table is fixed on a table
carriage G, G, Fig. 2, 3, and 4, which has a progressive and retrograde
motion. By sliding in a longitudinal direction on a frame J, J, Fig. 2, 3, and
4, after each cut the log is, by the retrograde motion of the carriage, cleared
from the saw; and in order to prepare the next cut, the table is advanced by
a parallel and lateral motion, regulated by two dividing wheels K, K, Fig. 2,
3, and 4, which determines the thickness of the board to be cut. The pro-
gressive and retrograde motions of the carriage is produced by means of a
pinion M, Fig. 2 and 4, fixed on a spindle N, Fig. 3 and 4. This pinion, by

page_text: the assistance of an intermediate cog wheel O, Fig. 2 and 4, which engages
into a rack P, P, Fig. 2, 3, and 4, is to give motion to the carriage. The
spindle N, Fig. 3 and 4, may be moved either by hand or any other manner.
In this Drawing it is intended to be moved by the steam engine by the assis-
tance of straps revolving on two drums Q, Q, Fig. 3 and 4. One of these
drums is to produce the progressive, and the other the retrograde, motion.
The Fig. 5 represents a section of a circular saw on the same principle as
that before described. This saw is of one single plate, and fixed to a meta
chuck A, to which it is fastened by a metal ring or clamp B, screwed to the
chuck A. The extremity of this saw may be shaped into a thin edge of the
form of that represented at D, Fig. 1. C represents at full size a section of
edge on which teeth are cut and set in
a part of the saw terminating into an
the usual manner.
Fig. 6 represents a section of a circular saw of one single plate, which is
entirely flat on one side and convex on the other. This plate is fixed to a
metal chuck in the manner described in Fig. 5. A represents at full size a
section of a part of the plate of the saw terminating into a thin edge.
In witness whereof, I, the said Mare Isambard Brunel, have hereunto
set my hand and seal, the Fourteenth day of September, in the year
of our Lord One thousand eight hundred and eight.