IMPROVEMENTS IN SAWING MACHINERY
Year: 1857

page_text: LETTERS PATENT to James Bird Sparke and Alfred Sparke, of the firm
of Sparke and Company, of the Thorn Lane Foundry, Norwich, in the
County of Norfolk, Engineers and Ironfounders, for the Invention of
"
PROVISIONAL SPECIFICATION left by the said James Bird Sparke and
Alfred Sparke at the Office of the Commissioners of Patents, with their
Petition, on the 8th April 1857.
We, JAMES BIRD SPARKE and ALFRED SPARKE, of the firm of Sparke &
Company, of the Thorn Lane Foundry, Norwich, in the County of Norfolk,
Engineers and Ironfounders, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SAWING MACHINERY," to be as follows:-
The first part of our Invention relates to that part of sawing machinery
which is employed to give motion to the timber under operation, for the
purpose of bringing it up to and keeping it in contact with the saw during
the cutting, and of withdrawing it from the saw when the cut is completed.
And this part of the Invention consists in the employment of a chain, one
end of which is attached by claws or otherwise to the timber, and the other
end of which is passed around or partially around two friction rolls or pulleys,
one of which is fixed upon a spindle driven by power or otherwise, and the
other is carried on an axle at the extremity of the short arm of a lever or of

page_text: the short arms of two similar levers. Upon the same axes as the two friction
rolls or pulleys, and rigidly connected with them, are two toothed wheels or
surfaces, which gear into each other, for the purpose of rendering the motions
of the said rolls or pulleys perfectly isochronous. A guide roll is fitted upon
or near the end of the saw bench for the purpose of guiding the chain from
the timber to the rolls or pulleys.
The second part of our Invention relates to the mode of driving reciprocating
saws, or saws which act upon the material to be cut by successive strokes,
and consists in the employment of a crank arm, the length of which may be
varied when it is desired to change the length of the saw's stroke, such crank
arm carrying at its extremity a pin, which works in a transverse slot in the
frame of the saw, and which, as the crank arm rotates, imparts the necessary
reciprocating motion to the saw. Instead of a crank arm and pin a disc
and adjustable pin or other equivalent contrivance may be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Bird Sparke and Alfred Sparke in the Great Seal
Patent Office on the 8th October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
BIRD SPARKE and ALFRED SPARKE, of the firm of Sparke and Company, of
the Thorn Lane Foundry, Norwich, in the County of Norfolk, Engineers and
Ironfounders, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of April, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
James Bird Sparke and Alfred Sparke, Her special licence that we, the said
James Bird Sparke and Alfred Sparke, our executors, administrators, and
assigns, or such others as we, the said James Bird Sparke and Alfred Sparke,
our 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 SAWING
MACHINERY," upon the condition (amongst others) that we, the said James
Bird Sparke and Alfred Sparke, or one of us, our executors or administrators,
by an instrument in writing under our or one of our, or their or one of their

page_text: hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, 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.
NOW KNOW YE, that we, the said James Bird Sparke and Alfred Sparke,
do hereby declare the nature of our 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.
hereunto annexed, that is to say :-
The first part of our Invention relates to that part of sawing machinery
which is employed to give motion to the timber under operation, for the
purpose of bringing it up to and keeping it in contact with the saw during
the cutting, and of withdrawing it from the saw when the cut is completed.
And this part of the Invention consists in the employment of a chain or rope,
one end of which is attached by claws or otherwise to the timber, and the
other end of which is passed around or partially around two friction rolls or
pulleys, one of which is fixed upon a spindle driven by power or otherwise,
and the other is carried on an axle at the extremity of the short arm of a
lever or of the short arms of two similar levers. Upon the same axes as the
two friction rolls or pulleys, and rigidly connected with them, are two toothed
wheels or surfaces, which gear into cach other, for the purpose of rendering
the motions of the said rolls or pulleys perfectly isochronous. A guide roll.
is fitted upon or near the end of the saw bench for the purpose of guiding.
the chain or rope from the timber to the rolls or pulleys.
The second part of our Invention relates to the mode of driving reciprocating
saws, or saws which act upon the material to be cut by successive strokes,
and consists in the employment of a crank arm, the length of which may be
varied when it is desired to change the length of the saw's stroke, such crank
arm carrying at its extremity a pin which works in a transverse slot in the
frame of the saw, and which, as the crank arm rotates, imparts the necessary
reciprocating motion to the saw. Instead of a crank arm and pin a disc and
adjustable pin or other equivalent contrivance may be employed.
The Drawings hereunto annexed represent the manner in which our Inven-
tion is carried into effect :-
Figure 1 is a side view, Figure 2 a plan, and Figure 3 an end elevation,
partly in section, of a circular sawing machine fitted with our improved
apparatus for bringing the timber to be cut up to the saw, keeping it in
contact with it, and withdrawing it from the saw when the cut is completed.

page_text: The machine is formed with a frame, parts of which run on rails, and the
tree A to be cut is attached thereto by dogs. This frame, together with the
circular saw, is formed and fitted as usual, or in any other suitable manner.
In this machine two ropes B; B¹, (the latter shown partly in dotted lines)
are employed, the former for imparting a forward motion to the timber A,
and the latter for giving it a backward motion. The rope B is attached at
one end by a claw a to the timber A, and is thence led over the roller b down
under a pulley c, and ascending on the other side of this pulley passes under
and then over a second pulley d, and then falls slack to the ground. The
lower pulley c is mounted upon an axle, driven by a worm wheel e, to which
motion is transmitted from the saw spindle through a belt f, a spindle g, a
bevil pinion h, a bevil wheel i, and a worm j. These parts are shewn sepa-
rately in Figures 4 and 5. The upper pinion d is mounted upon an axle,
carried by the levers l, k, which are fixed on a rocking shaft l. By raising
or depressing the lever m which is fixed on this shaft l, the amount of friction,
exerted upon the rope B between the pulleys c and d, may be increased or
diminished in such manner as to regulate the speed with which the timber
is moved, either by allowing the pulleys c and d to slip more or less within
the rope B, or by nipping them tightly against it. A cog wheel is mounted
upon the axle of each of the pulleys c, d, so as to gear into each other, in
order that the pulleys c, d, may be made to move with the same surface speed.
The rope B', by which the timber is run back from the saw, may be acted
upon by an arrangement of apparatus similar in construction and in action
to that just described, the pulleys being made larger in this case to give it
a greater speed if desired. A section of the pulleys c and d is shewn in
Figure 6.
Figures 7 and 8 illustrate the manner in which we drive reciprocating saws.
A is the driving shaft; B, the driving pulley; C, the crank arm or disc; D,
the pin, which enters a sliding block E, that works in the transverse slot F
in the frame of the saw. The crank radius may be increased or diminished
by varying the position of the pin D. The saw frame slides in suitable guides
in the standards G. The saw H is strained between the points I, J, and
works quite clear of the frame and standards.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, we declare that we claim,―
First, the employment, for the purpose of giving motion to timber in sawing
machinery, of a chain or rope, one end of which is attached to the timber
and the other passed around or partially around two friction pulleys or rolls,
arranged and put into action, as herein-before described.

page_text: Secondly, the employment, for the purpose of driving reciprocating saws, of
an adjustable crank arm or disc carrying a pin, which works in a slot in the
frame of the saw, arranged and put into action as herein-before described.
In witness whereof, we, the said James Bird Sparke and Alfred Sparke,
have hereunto set our hands and seals, this Sixth day of October, One
thousand eight hundred and fifty-seven.
JAMES B. SPARKE. (L.S.)
ALFRED SPARKE.
(L.S.)