IMPROVEMENTS IN SAWING OR CUTTING WOOD
Year: 1856

page_text: LETTERS PATENT to John M'Dowall, of Johnstone, in the County of
Renfrew, North Britain, Engineer, for the Invention of "IMPROVEMENTS
IN SAWING OR CUTTING WOOD."
Sealed the 16th December 1856, and dated the 17th October 1856.-
PROVISIONAL SPECIFICATION left by the said John McDowall at the
Office of the Commissioners of Patents, with his Petition, 'on the
17th October 1856.
I, JOHN MCDOWALL, of Johnstone, in the County of Renfrew, North
Britain, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SAWING OR CUTTING WOOD," to be as follows, that is to
say:
This Invention relates both to plain straight cut sawing and to differential
sawing for curved works, such as ship's timbers. As regards straight cutting,
the apparatus employed according to this Invention consists of a contrivance
whereby a series of saw frames may be simultaneously worked from one single
prime mover, whilst provision is made for the occasional disconnection of any
one frame without disturbing the action of the rest.
Under one modification this arrangement consists of a simple direct-action
steam engine, the cylinder of which is set up vertically upon a base frame,
whilst the piston's connecting rod passes upwards to actuate an overhead crank
on one end of a horizontal shaft, which is carried in bearings in the top of a
vertical frame, of a kind not unlike that which is usually adopted in common
direct action stationary engines; this crank shaft carries pulleys or wheels
for driving any other movement which may be required. The piston rod

page_text: clutch, forming the main connecting rod joint, also serves for receiving the
lower end of another connecting rod arrangement, which passes upwards to
a lever set on a rocking shaft carried in bearings in the framing at a lower
level than that of the crank shaft. The link which connects the clutch of
the piston rod with the rocking shaft may be disconnected by different
mechanical means, so as to leave the saw gate or moving frame at rest
whilst the engine department continues to move like an ordinary steam
engine; but in order to effect the stopping of the action of the saw gate
without stopping the engine, a contrivance of a second rocking shaft is intro-
duced. On the end of this shaft there is a slotted lever with a stud nut
worked by a screw, so that the link which connects this stud nut with the first
rocking shaft may be drawn towards the centre of the second rocking shaft,
thus leaving the swinging frame at rest. This may be effected in various
ways, as by a handle or hand wheel at the end of the screw operated upon
by hand or by two bevil wheels, one upon the end of the screw and the
other at a right angle to it on the rocking shaft immediately behind the
lever. On the boss of this last bevil wheel there are three pullies close to
one another, the central bearing being fixed to the boss and the other two
loose; and on the boss of the overhead crank there are two grooves forming
pulleys, from which the three pulleys on the rocking shaft receive motion
from two bands, one of them being crossed and the other open. It will
thus be obvious that by shifting the bands alternately on to the fast pulley the
screw nut will be drawn to the end of the lever, or brought back to the centre
of the rocking shaft, thus bringing the saw gate gradually into or out of motion
without interfering with the action of the steam engine or other prime mover.
A third rocking shaft may be carried along the front of any number of saw
frames, having a lever or arm at each frame, connecting the screw to a shifting
lever by a small link, and thus throwing out any one or all of the frames whilst
the motion of the third rocking shaft is still going on. Of course the motion
is still given to this rocking shaft by direct steam action or by other moving
power through the actuating rod as before. In cutting curved forms to this
Invention, the wood to be acted upon is clamped at each end between holders,
carried by a species of slide-rest arrangement, each end having its own slide,
and both being carried upon a traversing table and strong foundation bed like
those of an iron planing machine. The table bas a longitudinal traverse
movement in the direction of the length of the timber to be cut, and the two
slides upon it have a simultaneous traverse at right angles to the motion of
the table. This is effected by a longitudinal shaft running along the whole
length of the table having two pinions upon it, one on each end, so that when

page_text: one slide is pressed it carries the other along with it, having a toothed rack on
each side. These pinions are carried round by the shaft, and may be shifted
to suitable distances from one another as may be required, by a groove or
feather in the shaft. The drawing of the form to which the wood is to be cut
is prepared with ordinates or transverse measuring line (on a template table,
which is a fixture upon the lower bed plate,) at regular distances asunder.
When a proper piece of wood has been duly clamped down on the machine,
the operator measures off the curvature indicated by the drawing through the
agency of these ordinates, and then transfers the guide, thus obtained, to the
template table; this is done by a set with a holding bolt in each of the corre
sponding grooves of the table, at the same distance from a base line as is
exhibited by each ordinate upon the drawing. When all the ordinates have
thus got their set pieces adjusted, a piece of metal is threaded, as it were, along
the grooves of the holding sets, being curved from one to the other, so as to
reproduce the exact curve of the drawing. The combined slide-rest carrying
the wood is connected with this curved bar or pattern guide, having an arm
with a notch upon it clipping over the curved bar, so that as the supporting
table traverses along, the wood is compelled to traverse laterally in strict
accordance with the pattern curve. Hence, as the saw works in its cut the
exact bend in one direction is sawn out in the wood. For the curve in the
other direction, a second pattern guide or matrix is necessary. The saw,
carried by a suitable frame and actuated by a crank or other movement,
has its frame attached to a segmental bearing on the framing in such
manner that it can be angled in any desirable way. The pattern guide by
which this angling is effected is made in a manner similar to that in which
the other guide is produced, and it is fixed by knees to the long slding bed, a
proper connection being kept up between the guide surface and the swinging
movement of the saw, which swinging movement is struck from the bottom
inner corner or angle of the wood or that corner nearest to the saw. As
the sawing action proceeds, the two guides working simultaneously thus
produce whatever form may be predetermined, one curve being defined by the
shift of the wood itself, and the other by the angling of the saw frame. The
set bolts of the template table are so arranged that their actual holding
surfaces can swivel to suit the bend of the template bar.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John McDowall in the Great Seal Patent Office on the
17th April 1857....
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MCDOWALL, of Johnstone, in the County of Renfrew, North Britain, Engineer,
send greeting.
'WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of October, 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
John McDowall, Her special license that I, the said John McDowall, my
executors, administrators, and assigns, or such others as I, the said John
McDowall, my executors, administrators, or assignis, 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 OR
CUTTING WOOD," upon the condition (amongst others) that I, the said John
M Dowall, by an instrument in writing under my hand and seal, should
particularly describo 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John McDowall, do hereby declare the
nature of my said Invention,' and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
My said Invention relates both to plain straight cut sawing and to dif-
ferential sawing for curved work, such as ships' timbers. As regards straight
cutting, the apparatus employed according to this. Invention consists of a
contrivance whereby a series of saw frames may be simultaneously worked
from one single prime mover, whilst provision is made for the occasional dis-
connection of any one frame without disturbing the action of the rest. Under
one modification this arrangement consists of a simple direct action steam
engine, the cylinder of which is set up vertically upon a base frame, whilst the
piston's connecting rod passes upwards to actuate an overhead crank on one
end of a horizontal shaft, which is carried in bearings in the top of a vertical

page_text: frame, of a kind not unlike that which is usually adopted in common direct.
action stationary engines; this crank shaft carries pulleys or wheels for driving
any other movement which may be required. The piston rod clutch, forming the
main connecting rod joint, also serves for receiving the lower end of another
connecting rod arrangement, which passes upwards to a lever set on a rocking
shaft carried in bearings in the framing at a lower level than that of the crank
shaft. The link which connects the clutch of the piston rod with the rocking
shaft may be disconnected by different mechanical means, so as to leave the
saw gate or moving frame at rest whilst the engine department continues to
move like an ordinary steam engine; but in order to effect the stopping of the
action of the saw gate without stopping the engine, a contrivance of a second
rocking shaft is introduced. On the end of this shaft there is a slotted lever
with a stud nut worked by a screw, so that the link which connects this stud
nut with the first rocking shaft may be drawn towards the centre of the second
rocking shaft, thus leaving the swinging frame at rest. This may be effected
in various ways, as by a handle or hand wheel at the end of the screw operated
upon by hand or by two bevil wheels, one upon the end of the screw, and the
other at a right angle to it on the rocking shaft immediately behind the lever.
On the boss of this last bevil wheel there are three pulleys close to one another,
the central one being fixed to the boss and the other two loose; and on the
boss of the overhead crank there are two grooves forming pulleys, from which
the three pulleys on the rocking shaft receive motion from two bands, one of
them being crossed and the other open. It will thus be obvious that by
shifting the bands alternately on to the fast pulley the screw nut will be drawn
to the end of the lever, or brought back to the centre of the rocking shaft, thus
bringing the saw gate gradually into or out of motion without interfering with
the action of the steam engine or other prime mover. A third rocking shaft
may be carried along the front of any number of saw frames, having a lever or
arm at each frame connecting the screw to a shifting lever by a small link,
and thus throwing out any one or all of the frames whilst the motion of this
third rocking shaft is still going on. Of course the motion is still given to this
rocking shaft by direct steam action or by other moving power through the
actuating rod as before. In cutting curved forms according to this Invention,
the wood to be acted upon is clamped at each end between holders carried by
a species of slide-rest arrangement, each end having its own slide, and both
being carried upon a traversing table and strong foundation bed like those of
an iron planing machine. The table has a longitudinal traverse movement in
the direction of the length of the timber to be cut, and the two slides- uppn it
have a simultaneous traverse at right angles to the motion of the table. This

page_text: is effected by a longitudinal shaft running along the whole length of the table,
having two pinions upon it, one on each end, so that when one slide is pressed
it carries the other along with it, having a toothed rack on each side. These
pinions are carried round by the shaft, and may be shifted to suitable distances
from one another as may be required by a groove or feather in the shaft.
The drawing of the form to which the wood is to be cut is prepared with ordi-
nates or transverse measuring lines (on a template table, which is a fixture upon
the lower bed plate,) at regular distances asunder. When a proper piece of
wood has been duly clamped down on the machine, the operator measures off
the curvature indicated by the drawing through the agency of these ordinates,
and then transfers the guide thus obtained to the template table. This is done
by a set with a holding bolt in each of the corresponding grooves of the table,
at the same distance from a base line as is exhibited by each ordinate upon the
drawing. When all the ordinates have thus got their set pieces adjusted, a
piece of thin metal or steel plate is threaded, as it were, along the grooves of
the holding sets, being curved from one to the other, so as to reproduce the
exact curve of the drawing. The combined slide-rest carrying the wood is
connected with this curved bar or pattern guide, having an arm with a notch
upon it clipping over the curved bar, so that as the supporting table traverses
along, the wood is compelled to traverse laterally in strict accordance with the
pattern curve. Hence, as the saw works in its cut, the exact bend in one
direction is sawn out in the wood. For the curve in the other direction a
second pattern guide or matrix is necessary. The saw, carried by a suitable
frame and actuated by a crank or other movement, bas its frame attached to a
segmental bearing on the framing in such manner that it can be angled in any
desirable way. The pattern guide by which this angling is effected is made in
a manner similar to that in which the other guide is produced, and it is fixed
by knees to the long sliding bed, a proper connection being kept up between
the guide surface and the swinging movement of the saw, which swinging
movement is struck from the bottom inner corner or angle of the wood or that
corner nearest to the saw. As the sawing action proceeds, the two guides
working simultaneously thus produce whatever form may be predetermined,
one curve being defined by the shift of the wood itself, and the other by the
angling of the saw frame. The set bolts of the template table are so arranged
that their actual holding surfaces can swivel to suit the bend of the emplate
bar.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several illustrative Figures on the explanatory
Sheet of Drawings, which I have hereunto appended for the purpose of

page_text: showing certain modifications under which my Invention may be judiciously
carried into practical effect.
Figure 1, on Sheet 1 of my Drawings, is a main front elevation of one.
modification of my machinery as adapted for straight cutting, wherein a series
of saw frames may be simultaneously worked from one single prime mover,
provisoin being made for the occasional disconnection of any one frame, without
disturbing the action of the rest. Figure 2 is a corresponding side elevation
of the machinery as taken at right angles to Figure 1, and looking on the
actuating steam cylinder side. The framing of this machinery mainly con-
sists of a pair of vertical parallel side standards A, bolted down to a base or
sole plate on the floor of the saw mill by base flanges; these standards being
surmounted by an entablature B to carry the overhead engine shaft and other
details, whilst a further transverse connection_is afforded by transverse tie rods.
The same base plate carries the vertical steam cylinder C, which is the prime
mover of the machinery. The upper flange or cover of this cylinder carries
a pair of vertical parallel guides D, against which the slide blocks E of the
piston rod cross head, a connecting rod F passes upwards to the joint pin of
the crank G, fast on the overhanging end of the overhead crank shaft H, sup-
ported at the front end in a pedestal bearing I, carried by the main framing,
and at the other in a corresponding bearing J, supported by the wall K. This
shaft has upon it a fly wheel L, and a broad belt pulley M for actuating any
other movement which may be required. The steam from the boiler is sup-
plied to the cylinder valve chest N by a pipe O, the exhaust taking place by
the opposite pipe P. The slide valve is worked from a stud pin in the return
or overhanging crank Q, carried by the main crank pin, a descending con-
necting rod R being carried down to a short lever S on the horizontal rocking
shaft T, working in bearings on the cylinder cover. This rocking shaft has
keyed upon it a valve lever U, which is directly connected at its free end to
the vertical slide valve spindle V. The clutch of the piston rod cross head
serves also to form the joint for the lower end of the ascending connecting
rod W, which is in two separate lengths; the upper end of this connecting
rod W is jointed to a stud pin in the free end of a lever X fast on one end of
a rocking shaft Y, which is carried in bearing in the main framing. This
rocking shaft carries at its longitudinal centre a second lever Z, the free end
of which has in it a duplex joint stud, forming the joint connection with the
parallel links a, which again are jointed at their lower end with the connecting
link piece 6 of the upper bar c of the saw frame. The lower bar of the saw
frame is at d, and the whole is guided in its vertical travers by the vertical guide
piece e, carried by the main framing. I have referred to the connecting rod W

page_text: as a single rod, but it is really in two separate pieces. The upper joint of the
lower length is connected to a fixed stud pin set in an end eye in the free end
of a slotted rocking lever f, whilst the lower joint of the upper half of the rod
is jointed to a stud pin carried by a traversing nut fitted into the slot or groove
of the lever f. It is this lever f which allows of the stoppage of the action of
the saw gate without stopping the actuating engine, so that other saw gates
connected with the engine can still continue working. It is carried upon the
outer end of a secondary rocking shaft, carried in bearings in the main framing,
and passing off transversely to other saw gates, as at g, where the shaft is
shown broken away. The groove of the lever f has in it a longitudinal screw
spindle, connected at its outer end with the traversing bearing of the lower
joint of the upper half of the connecting rod W. The other end of the
screw spindle carries a bevil pinion h in gear with a bevil pinion, loose on
the secondary rocking shaft. This pinion i is in one piece, with a triple cord
pulley, round which open and crossed endless cords are passed from a cor-
responding duplex pulley k on the overhead crank shaft. The central pulley
of the lower set is fast on the boss of the bevil pinion-i,. and 'the other two are
loose; thus by shifting the open and crossed belts or. cords alternately on to
the central fast pulley of 'the lower series, the screw.nut of the upper or saw
gate connecting rod is drawn to the end of the lever, or brought back to the
dead centre of the rocking shaft. This adjustment of course has the effect
of gradually bringing the saw gate into or out of motion, without in any way
interfering with the action of the engine."
In the example of sawing machinery which I have "herein shown, the saw
.gate is supposed to be operating upon two logs of timber l, m, at once. These
logs are set up against the two opposite sides of a central fence n, and they
are held down by the overhead rollers o upon the traversing feed rollers p
which are actuated by the "silent" feed" motion q, which again is worked
from the eccentric r on the main overhead crank shaft H. The amount of
the feed is adjustable by the hand wheel 8, which actuates an internal screw
spindle in the inclined lever t. This ścrew has upon it a nut, carrying a stud
pin for the upper. joint of the lower connecting rod 'u, the lower end of which
is jointed to the "silent feed" motion below. The upper short connecting
rod v, attached directly to the eccentric, has its lower end jointed directly to a
stud 'pin on the back arm of the adjusting lever t; hence, as the internal nut
in this lever is screwed back or forward, the effective leverage actión upon the
silent feed motion is increased or diminished so as to effect the adjustment of
the rate of traverse of the timber up to the cut with the greatest nicety. The
two small cross shafts w, each carrying a pair of actuating hand wheels, serve

page_text: for the elevation and depression of the upper pressing or retaining rollers o
bearing upon the timber. These shafts carry at each end a bevil pinion in
gear with a corresponding bevil pinion fast on the upper ends of a set of four
vertical screw spindles, working in grooves or recesses in the main standards
of.the framing. These, screw spindles are: entered through nuts carried by
the vertically. traversing bracket bearings of the rollers o; and hence these
rollers can be elevated or lowered as required. The logs are kept up against
their fences, or stationary guide surfaces by pressure lever, rollers æ, carried
upon vertical spindles y, and capable of manual adjustment by the band
levers z. These spindles carry at their upper ends segmental worm wheels 1
in gear with worms .2, .carried by the. short horizontal hand wheel,, shafts 3.
These worms are connected to their shafts, by spring boxes, so contrived that
although when the hand wheels are turned, the worm wheel action serves to
turn, round the spindles y, and make the rollers upon, the levers x to. bear
against the outside faces of the logs, yet the spring action admits of the con-
trary turning of the spindles by the hand levers,, when it is wished to relieve
the logs from the pressure of these lever rollers.
!
The second part of my improvements in sawing or cutting wood is,shown
in my Sheet 2 of illustrative Drawings of my Inventon. These arrange:
ments of machinery are intended for sawing or cutting. wood to, curved or
bevilled forms, or to shapes in which a curve and a bevil are combined..
Figure 3, on this Sheet of Drawings, is a side or end elevation of the machine
complete; Figure 4, is a longitudinal elevation of the back part of the machine,
with a portion of it broken away; and Figure 5 is a complete plan, cor-
responding to Figures 3 and 4. In describing this machine, it, may be con-
venient to refer, firstly, to the parts for holding and giving motion to the wood;
secondly, to the means, whereby the, wood is made to describe a curved, a
differential,.or zig-zag path; thirdly, to the means employed for actuating the
saw; and fourthly, to the mechanical arrangement for giving an angular motion
to the saw, for the purpose of obtaining a bevil or angular, sweep.in sawing
or cutting wood. The portion of the machine on which the mechanical arrange-
ment for traversing the wood, to and fro is carried, is upon the foundation
bed A, the whole of the and other parts of the machinery-being supported on
a solid foundation on the floor. The upper part of each of the side bed plates
A forms the slide or shears, upon which is placed the sliding carriage on
traversing table B, which is made to slide upon the shears A. Upon the
traversing carriage or table B are fitted transversely two sliding tables C..on
which the transverse slides D travel.. The clamping apparatus, consists of, a
pair of holders or clamps E projecting from each of the sliding plates, D.;; tho

page_text: lower holder of each clamping apparatus is a fixture, the upper one travels
vertically on the fixed standard F. Motion is given to the upper holder by
means of the vertical screws G, which are supported at the upper part by the
cross head fitted on the standard F. The screws are put in motion by means
of a pinion H fitted to a nut boss on the pinion H, which pinion gears with a
pair of pinions I fitted to the screws G. The pinion II is turned by means of
a screw key or spanner made to fit the nut boss. The rotation of the pinion
I gives motion to the pinions I, and thereby causes the screws G to raise or
lower the upper holder E, as required. The upper clamp or holder has also
another clamp projecting from its side at right angles to the former. A
longitudinal movement is given to the timber by means of the sliding carriage
or traversing table B, which is made to curve downwards between the sides
of the shears A. This curved part J is made with openings in it, as shown in
the plan, Figure 5; these are for the purpose of lightening this part of the
machine; and to the under side of the curved part J is bolted a toothed rack
K. The upper part of the curvature J affords space in which the pinions are
fitted for giving a transverse motion to the traversing tables D. Motion is
given to the rack K, and consequently to the traversing table B, by means of
a pinion L fast on the main driving shaft M; this shaft has keyed upon it the
bevil wheel N and hand wheel O. This bevil wheel N gears with a bevil
pinion P on the vertical shaft Q, on the upper part of which is the screw
wheel R in gear with the worm on the shaft S. The journals of the shaft S
are carried in stud bearings bolted to the standards T, and on this shaft S is a
double grooved pulley U, in one groove an open band is passed, and in the
other groove there is a crossed band, and both of these bands are put in motion
by other pulleys driven by the prime mover. By means of the arrangement
of an open and a crossed band, which are to be brought into action alternately
by shifting the bands from the fast to the loose pulley, the traversing table B
is caused to traverse to and fro. The vertical shaft Q is fitted with an
arrangement, by means of which the bevil pinion P is instantly thrown out of
gear with the wheel N. Upon a stud V, projecting from the framing, is
fitted a forked lever W, which works in a groove of the boss of the collar on
the pinion P of the shaft Q, from which a feather projects. The boss of the
forked lever also carries the weighted lever X; when this lever is moved
to the left of the position shown in Figure 3, the forked lever raises the pinion.
P, which slides up the shaft Q out of gear with the wheel N, thereby stopping
the rotation of the shaft M; the table B is then free to be moved to and fro
by the hand wheel O, if required. An uniform transverse motion is given to
the two slides D of the holding apparatus by means of pinions Y fitted on. the:

page_text: shaft Z, carried in a bearing in the end of the carriage B, which pinions are
in gear with a rack a on the under side of each of the transverse slides D.
The shaft Z has a longitudinal groove made in it, in which a key on the inside
of each of the pinions Y travels. By means of this arrangement, the trans-
verse traverse of the two slides D are rendered exactly uniform, for when the
pinions Y and their shaft rotates, they carry with them the transverse slides D.
The longitudinal groove in the shaft admits of the beds C of the slides D and
their pinions Y being pushed along the shaft, and thereby adjusted with regard
to their distance from each other, according to the length of the timber to be
cut. If the transverse slides D and the timber to be cut are caused to move
to or from a line parallel to the side of the timber, the saw will describe a
curved path, corresponding to the distance which the timber is made to deviate
from the parallel line. The particular curve which it is required for the saw to
make is obtained by means of an adjustable template, which moves the timber
to and fro, corresponding exactly to the predetermined curvature given to the
template. The template table b is bolted to and supported by three brackets c,
which project from the sides of the shears or bed plate A. At regular
distances apart in the table b, slots d are made, in which the metal plates e
traverse; each of these plates may be fixed at any point in the slots d by means
of a nut and bolt. The moveable plates e carry the sets f, which are cylindrical
pieces of metal which swivel in the plates e; these "sets" have a "cross
cut or recess made therein, and a pinching screw at right angles to it. Tho
sides of the template table band of the slots d are graduated or divided into
inches and parts thereof, and a horizontal mark is made ou each of the plates e
in a line with the centre of the "sets "f. In the Drawing, Figure 5, the slots
are represented as being six inches apart, and supposing a curve is to be set
out, the operator having a drawing of the required curve before him, and on
which the ordinates are set off to a specified scale, he proceeds to adjust the
first plate e to the number of inches corresponding to the first ordinate on his
He then proceeds
drawing, and fixes the plate e in that position by its nut.
to adjust the next plate e corresponding to the second ordinate on his drawing,
and fixes that plate in like manner, and so on throughout the series.
all the "sets" fhave been thus arranged, a thin steel band g is passed
between each of the openings or recesses in the sets f, and retained therein
by the pinching screws. Whatever curvature may be given to this steel ban
or template g, the timber is caused to follow a line exactly parallel to it, and
consequently if the timber be cut by a saw action, vertically, it will be cut to a
corresponding curve. The timber is guided in its varying transverse traverse
by means of the arm h, which is buited to the traversing slide D, and is
"
When

page_text: adjustable by means of slots and bolts at its inner end. On the outer or pro-
jecting part of the arm h is a stud i which swivels in an eye at the end of the
arm. The lower part of this stud is divided by a cut or notch, and when put
into action, the stud is lowered over the edge of the steel band g.. On the
upper part of the arm i is a graduated dial plate and index hand j, by means
of which the number of degrees the saw's path varies from a right line is
indicated, and serves to show the tangential line of the part of the curve that
is, being cut at the time being. The ordinates of the curve of the steel band
gare. marked from the red base line as intersecting each "set"; a base line
is also marked on the timber to be cut in Figure 5, this line indicates the
saw's path at each instant of its progress through the wood. Thus, the first
ordinate e¹ on the template corresponds to the ordinate a¹ on the timber, and
the next ordinate e² corresponds to the ordinate a², and so on in like manner
throughout the series. In other words, as the traversing table B is moved in a
longitudinal direction, the stud i on the arm causes the transverse traversing
tables. D to move to and fro in accordance with the curve, the timber, being
held fast. by the clamping apparatus, obviously travels in a corresponding
parallel line, meanwhile, as the saw is moving up and down, it follows that the
wood is cut in a line agreeing with its deviation froin a right line. The
mechanical arrangement connected with the saw, and the means for giving it a
rectilinear reciprocatory motion are as follows:-The saw k is connected at its
upper part to a spindle which passes through the wheel k³, and its lower part is
attached to the spindle of a similar wheel ³. These wheels are each supported
by an arm or cross head.l, which is fast to the ends of the hollow stay m;
which with the tie rods attached to the other ends of the cross head 1, form the
saw frame. Down through the hollow stay m passes a light shaft, on the upper
and lower ends of which is a wheel o similar to and in gear with the wheels ³.
The hollow stay m moves in the cylindrical guide m', which is connected to
the pillars by means of the stays m³, which are bolted to the pillar and hollow
stay the guide m¹ serves to keep the saw in a parallel line. The saw is
tightened by the adjusting nuts p on the spindle passing through the upper
wheel, and the tension rods n serve to counteract the strain of the saw upon
the projecting arms of the cross head l, and for this purpose the rods are fitted
with adjusting nuts by which their length may be altered as required. The
saw k is driven by means of a belt on the pulley 9 fast to the crank shaft r
which passes through an elongated boss in the pillars, having its crank t at
the other end, to the pin of which is attached the connecting rod u, its upper
end being attached to a journal in the cross head 1; the saw and its frame is
thus made to reciprocate by the rotatory motion of the crank.. For the purpose

page_text: of giving a regular and smooth motion to the saw, a fly wheel V is placed
on the crank shaft in the centre of the column s. The driving bell passes
from the belt pulley 9 to the main driving pulley, which must be suf-
ficiently distant to admit of the pillars, and its connected mechanism being
raised and lowered without slackening the belt, or otherwise interfering with
the rotatory action of the pulley q. The object of raising and lowering the
pillars, and the parts connected with it, is to place the saw at any required
angle, by which means the timber may be cut at a bevil as well as in a curved
line. The pillars is placed between the two segmentally-shaped, vertical
standards T, which are bolted at the lower part to the bed plate of the machine;
and united at the upper part by a transverse tie bar W. On the inside of eacli
of these standards is a segmentally-shaped guide X forming a groove, the
outline of which is shown by dotted lines in Figure 3, and projecting from
the pillar's is a curved flange y working in the grooves of the guides X.
Bolted to one side of the curved flange is a segmental wheel Z. A portion.of
the teeth of this segmental wheel is shown in the centre of the standards T.
dotted in Figure 3. The segmental wheel Z is in gear with the vertical rack
1, the upper part of which is fast-to a rope or chain, having a balance weight
by. which it is suspended over a pulley, and the strain of this portion of the
machine is thus taken off. This portion of the machinery is in connection
with the template, by which the bevil curves are produced in the cutting of
the wood, which is somewhat similar to the arrangement of the template
before described in reference to cutting. curves in timber.. The bevil template
table 2 is caused to travel to and fro by means of a rack 3 on its under side,
which is in gear with a pinion 4 on the shaft 5. in the bed plate 6 of the
template table 2. Motion is given to the shaft 5 and its wheel. 7 by means
of a pinion 8 on the driving shaft M through the intermediate wheels 9,
carried by a stud 10 projecting from the bed plate A. By means of-this
gearing the speed of the shaft, and consequently the traverse of the bevil
template table, may be accelerated or decreased as required by altering -the
relative sizes of the wheels 7 and 9. The adjusting plates and "sets"
are arranged on the bevil template table in a similar manner to those before
described, the ordinates 61, 62, and so on, being measured off as indi
eated by the red lines from a scale drawing of the bevil curve, and the steel
band 11 fitted and clipped by the pinching screws in the sets. The bevil
line is indicated on the timber by the inner dotted line, and the ordinates
thereon correspond to those of the bevil curve. In this part of the machine
the saw is caused to assume the angle corresponding to the curve of the band
by means of the rod 12, on which is fitted a sliding stud 13 held by a pinching

page_text: screw; the slide has a swivelling stud 14 with a cut or notch in it, which is
slipped over the upper edge of the band 11, as before described. The bevil
template table 2 is put in motion by the gearing, and is caused to travel either
at the same rate as the timber, or at some predetermined ratio thereto; as the
stud 14 follows the deviations of the curve the rod is moved to and fro in
accordance therewith. The other end of the rod is attached to a bell crank
lever 15, and the movement of the rod causes the longer arm of the crank
lever to rise or fall. On the stud forming the fulcrum of the bell crank lever
is a double-grooved pulley 16 loose on the stud, and at the other end of the
lever 15 is a similar pulley 17 on a spindle 18; these pulleys are put in motion
.by a band 19 passing round the groove of the double pulley, and connected
with another pulley driven by the prime mover. On the opposite end of the
spindle 18 of the pulley is a friction roller 19, the pressure of which against
either of the discs 20 and 21 puts them alternately into motion, but in opposite
directions. The spindle 22 of the discs 20 and 21 rotates in a footstep bear-
ing in the bracket 23, which project from the rack 1; the lower end of the
spindle has upon it a pinion 24, which gives motion to a wheel 25, the shaft
26 of which likewise rotates in the brackets 23. The lower part of the
shaft 26 has a long external screw made upon it, which works in a cor-
responding internal screw fitted in the fixed bracket 27, which projects from
the lower part of the framing. As the longer arm of the bell crank lever 15
is raised or depressed, the pulleys 16, 17, being kept in motion, the friction
roller 19 is alternately brought in contact with the discs 20 and 21, the rota-
tion of which causes the wheel 25 to rotate, and through it the spindle 26, by
which means the screw on its lower part travels either up or down the internal
fixed screw in the bracket 27. This action causes the rack 1 to be raised or
lowered, which carries with it the segmental wheel X, pillar s, saw frame and
working mechanism, thereby causing the saw to assume an angular position
more or less inclined according to the elevation or depression of the segmental
wheel X. At the back part of the machine is an arrangement by means of
which the motion of the saw about its axial line may be regulated, so as to
correspond with the direction which it has to take in passing through the
wood: By means of this arrangement the saw is turned in such manner as
always to present its teeth to the line it is intended to follow. This is effected
by means of an index hand travelling over a graduated plate, the hand being
made to correspond to the hand of the index plate j. The worm shaft 28 is
turned by means of a handle on its outer end, the screw on it sinner end is in
gear with the worm wheel 29 on the the top of the pillar s. The screw on
the outer end of the shaft 28 gears into a worm wheel 30, which gives a

page_text: rotatory motion to the index hand of the graduated plate 31. The worm
wheel 29 is free to slide up and down the shaft 32, which has a feather made
on it, by means of which the worm wheel 29 carrios the shaft 32 and wheel 33
with it, when it is caused to rotate by turning the handle of the worm shaft
28. The shaft 32 is carried downwards some distance to give it a sufficient
bearing. By means of the arrangement of the loose wheel 29 the recipro-
catory motion of the upper cross head 7, as it follows the motion of the crank,
does not interfere with the action of the worm shaft 28 on the worm wheels
29 and 30. When the handle is turned, the worm wheel 29 causes the
wheel 33 on the upper part of the shaft 32 to rotate, and this wheel gives
motion to the wheels o on the shaft m, and through these wheels the wheels k¹
and are caused, to rotate, and thereby turn the saw upon its axis. The
number of degrees of its rotation being indicated by the index band of the
graduated plate 31. As the saw is working, the attendant watches the varia-
tion of the index hand on the dial of the arm h as it deviates from the plumb
line, and by means of the handle he causes the index hand of the plate 31 to
deviate in a like manner; this deviation will cause the saw to turn upon its
axis to an angle corresponding to the varying tangential lines of the template g.
In the description herein-before given of the parts connected with the tem-
plate g, the arm h is described as being guided by the template, while that of
the bevil template is guided by the lever which serves merely to raise or
depress the bell crank lever, by means of which the movements are effected.
In this latter arrangement the heavy portions of the mechanism are counter-
balanced, by means of which a very slight force only is required for causing
the saw to follow the curve of the bevil template. This counterbalance
arrangement may also be applied to the mechanism for cutting curved lines,
in which modification the timber to be cut and holding apparatus would be so
arranged and counterbalanced as to require a very trifling amount of power to
move the wood to and from the template. It should also be particularly
observed that the bottom line of the timber is in a line with the centre of the
crank shaft, and this point forms the centre of motion about which the saw
gyrates, and that under all circumstances the bottom edge of the timber is in
this position. It will be obvious from the foregoing that timber may be cut
to any curve or bevil with ease and certainty, and without incurring waste.
Ilaving now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without

page_text: deviating from the principles or main features of my Invention; but what
I consider to be 'novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-
First; the general' arrangement and construction of machinery or apparatus
to be used for sawing or cutting timber, as herein-before described.
Second, the system or mode of working a series of saw gates or frames from
one single prime mover, wherein any one or more of such saw', gates or frames
may be disconnected at pleasure without disturbing the action of the rest, or
interfering with the motion of the engine or prime mover.
Third, the application and use, in machinery or apparatus for sawing or
cutting timber, of an' adjusting screw and 'nut lever for the purpose of sus-
pending the motion of saw gates or frames without suspending the action of
the prime mover, as herein-before described.
Fourth, the 'application and use of the spring worm action, as herein-before
described, for the purpose of engaging and disengaging the lateral pressure
rollers upon the timber.
"
Fifth; the system or mode of sawing or cutting curvilinear or combined
curvilinear and bevilled or differential forms in timber by means of adjustable
template guides, as herein-before described.
Sixth, the system or mode of forming or adjusting curved or differentially
shaped templates or sawing guides for sawing or cutting timber to curved or
differential forms by the use or agency of flexible template pieces set in
holders, as herein-before described.
Seventh; the system or mode of sawing or cutting timber to curved or
differential forms wherein the drawing or delineation of the form to which the
timber is to be sawn or cut is primarily prepared with ordinates or transverse
measuring lines,' the values of such ordinates being thereafter transferred to
the working template tables, as herein-before described.
Eighth, the system or mode of arranging and constructing machinery or
apparatus for sawing in curved or differential lines, wherein the sawing edge
is always directed towards the line in which the saw is to travel, as herein-
before described.
ン
**
"
In witness whereof, I, the said John McDowall, have hereunto set my
hand and seal, this Fifteenth day of April, One thousand eight hundred
and fifty-seven.
JOHN MCDOWALL. (L.S.)