IMPROVEMENTS IN SAWING MACHINERY
Year: 1871

page_text: LETTERS PATENT to John Walker Mc Carter, of the City Saw Mills,
Foyle Street, Londonderry, in the County of Londonderry, Ireland,
VDY "
Sealed the 12th March 1872, and dated the 21st September 1871.
PROVISIONAL SPECIFICATION left by the said John Walker Mc Carter
at the Office of the Commissioners of Patents, with his Petition,
on the 21st September 1871.
I, JOHN WALKER: MC CARTER, of the City Saw Mills, Foyle Street,
Londonderry, in the County of Londonderry, Ireland, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SAWING
MACHINERY,” to be as follows, that is to say :-
This Invention has principally for its object to construct sawing
machinery so as to be capable of being driven at a greater than the
ordinary speed, and it consists in the first place in connecting four
reciprocating frames to cranks placed at right angles to each other on

page_text: one revolving driving shaft, so that they may counterbalance each
other, and so that vibration may be reduced to a minimum.
In the second place the saw frames are jointed to radius bars at their
upper and lower ends; these radius bars being at right angles or nearly
so to the saw frames in their middle positions, and extending in
opposite directions, being centred on fixed or rocking spindles or on
cranks or eccentrics, which last may be made to revolve or oscillate
to modify the motion of the saw frames. These arrangements involve
very much less friction than the ordinary guides.
In the third place the wood to be sawn is guided by rollers acting
independently of the usual fixed fences, each roller being formed with
two flanges, one of which is movable and connected to the body by
springs to admit of adaptation to inequalities of thickness. The
movable flange is part of a disc formed with a cylindrical recess, into
which the body of the roller enters, so that the movement takes
place without any groove being exposed or liable to be choked with
sawdust.
In the fourth place any convenient feed motion of a continuous kind
is combined with a slightly convex curvature of the line of saw teeth;
and with this curvature, and the peculiar motion of the saw frames, due 2
to their connection with the radius bars, the saws are relieved back
whilst rising so as to allow the wood to continue to move forward.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Walker Mc Carter in the Great Seal Patent
Office on the 20th March 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WALKER MC CARTER, of the City Saw Mills, Foyle Street, Londonderry,
in the County of Londonderry, Ireland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of September, in the 3
year of our Lord One thousand eight hundred and seventy-one, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Walker Mc Carter,
Her special licence that I, the said John Walker Mc Carter, my

page_text: executors, administrators, and assigns, or such others as I, the said
John Walker Mc Carter, 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 SAWING MACHINERY,"
upon the condition (amongst others) that I, the said John Walker
Mc Carter, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should par-
ticularly 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 I, the said John Walker Mc Carter, 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 in writing, reference being had to the
accompanying Drawings, that is to say :-
My said Invention has principally for its object the constructing of
sawing machinery, so as to be capable of being driven at a greater than
the ordinary speed; and it consists in the first place in connecting four
reciprocating frames to cranks placed at right angles to each other on
one revolving driving shaft, so that they may counterbalance each
other, and so that vibration may be reduced to a minimum.
1
In the second place I joint the saw frame to radius bars at their
upper and lower ends, these radius bars being centred on fixed or
rocking spindles or on cranks or eccentrics, which last may be made
to revolve or oscillate to modify the motion of the saw frames.
In the third place the wood to be sawn is guided by rollers acting
independently of the usual fixed fences, each roller being formed with
two flanges, one of which is movable.
In the fourth place I combine any convenient feed motion of a
continuous kind with a slightly convex curvature of the line of saw
teeth, and with this curvature and the peculiar motion of the saw
frames due to their being guided by radius bars instead of the ordinary

page_text: slide guides, the saws are relieved back whilst rising so as to allow the
wood to continue to move forward.
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append a Sheet of
explanatory Drawings to be herein-after referred to, and representing
a sawing machine as made with my improvements.
In these Drawings the same reference numerals are used to mark the
same or like parts wherever they are repeated.
Figure 1 is a plan partly in horizontal section, and Figure 2 is a front
elevation partly in vertical section, whilst Figure 3 is a transverse
vertical section, and Figure 4 is an end elevation.
The framing of the machine comprises a strong rectangular bed
frame 1, down on which are bolted five vertical standards 2, in the
interstices between which the four saw frames work. The upper ends
of the frame standards 2 have bolted to them a head frame or,
entablature 3, and the outer standards are additionally secured and
stiffened by being bolted to transverse beams 4, fixed in the walls of the
building containing the machinery. The crank shaft 5 for working the
saw frames is carried at the top in five bearings on the entablature 3,
and in two outer bearings 6 upon beams 7, and it is fitted with fast
and loose driving pulleys 8 near each end to admit of being doubly
driven, so that half the strain only is transmitted through each end of
the shaft. The four cranks 9 are placed in four different positions, the
two middle ones being diametrically opposite to each other and at
right angles to the two outer ones, which last are also diametrically
opposite to each other. Each saw frame consists of two side bars 10,
connected by horizontal stays 11, 12, 13, fixed to them by rivetting,
and the connecting rods 14 from the cranks 9 above are jointed upon
the uppermost stays 11. The saw frames 10 are fitted to work easily
between the frame standards 2, which prevent any lateral deviation, but
instead of the pressure due to the resistance to the sawing action
being borne by guides of the ordinary kind, it is sustained, and the saw
frames are guided by radius bars 15, 16. Two radius bars 15 are jointed
upon studs at the upper ends of each saw frame 10, and the other ends
of these bars 15 are jointed on studs 17 fixed in projecting parts of the
frame standards 2. Other two radius bars 16 are jointed on the bottom
stay 13 of each saw frame 10, and being extended away from the saw
1

page_text: frame in the opposite direction to that of the upper radius bars 15,
have their outer ends jointed on a horizontal shaft 18 fixed across the
lower parts of the frame standards 2. When the saw frames 10 are at
about the middles of their strokes, the radius bars 15, 16, are horizontal
and their action is to guide the saw frames in a vertical movement and
to keep, them almost (although not quite) vertical throughout that
movement, the arrangement involving very much less friction than is
experienced with ordinary saw frame guides.
In connection with each saw frame 10 there are two pairs of flanged
rollers 19, 20, for guiding and feeding the wood through whilst being
sawn; one pair 19 being below the wood, and the other 20 above it.
The several lower feed rollers 19 are upon two horizontal shafts 21,
carried in bearings in the frame standards 2, and driven so as to feed
forward the wood passing over them by means of spur wheels 22 on
their ends. The wheels 22 are driven in a continuous manner by
gearing which will be easily understood from the Drawings, being
partly indicated by red circles in Figure 4, and which derives its motion
from the crank shaft 5 above, a part of the gearing consisting of two
graduated pulleys 23, 24, to be connected by a belt by means of
which the rate of feed relatively to the speed of the crank shaft 5 can
be adjusted to suit different kinds of wood. The upper feed rollers 20
are carried quite independently of each other, each on a pin fixed to a
separate block 25 fitted to slide in a slot in the frame standard 2, and
made adjustable vertically by screw spindles 26 actuated through bevil
wheels 27 by hand wheels 28. Each of the feed rollers 19, 20, is made
with two flanges, one 29 of which is movable; such movable flange
being connected to the body of the roller by bolts which are held by
rubber or spiral springs in recesses in the body. The movable flange 29
can thus yield to accommodate inequalities in the wood; but it is
constructed as part of a disc formed with a cylindrical recess into
which the body of the roller enters, so that the movement of the flange
takes place without any groove being exposed or liable to be choked
with sawdust.
One of the saw blades 30 is shown in Figure 3, the line of the saw
teeth having a slight convex curvature as and for the purposes herein.
before explained..
Having thus particularly described my said Invention and the manner
of performing the same, I have to state that I do not restrict myself

page_text: to the precise details herein described or delineated, but that what I
believe to be novel and original, and claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,―
1. The arranging or combining together of the parts of sawing
machinery, substantially in the improved manner as herein described
and delineated.
2. The combining together of four saw frames worked by separate
cranks equally distributed round the shaft so that the frames and
connections may counterbalance each other, as herein-before described.
3. The guiding of reciprocating saw frames by means of radius bars, 1
substantially as herein-before described.
4. The guiding and feeding of the wood to be sawn by flanged rollers
and without fixed fences, the rollers being made with yielding flanges
recessed to work over the bodies of the rollers, substantially as herein.
before described.
5. The combining of a convex curvature of the line of saw teeth
with the guiding of the saw frames by radius bars and with a
continuous feed, substantially as herein-before described.
]
In witness whereof, I, the said John Walker Mc Carter, have
hereunto set my hand and seal, this Sixteenth day of March, 2
in the year of our Lord One thousand eight hundred and
seventy-two.
TATT
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