IMPROVEMENTS IN MACHINERY FOR CUTTING WOOD AND OTHER MATERIALS
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
CHEVERTON, of Pratt Street, Camden Town, in the County of Middlesex,
Sculptor in Ivory, send greeting.
any
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Sixteenth day of January, in the seventh year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Benjamin
Cheverton, Her especial licence, full power, sole privilege and authority, that
I, the said Benjamin Cheverton, my exors, admors, and assigns, or such others
as I, the said Benjamin Cheverton, my exors, admors, and assigns, should at
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 "IMPROVEMENTS IN MACHINERY FOR CUTTING WOOD AND
OTHER MATERIALS;" in which said Letters Patent is contained a proviso, that
I, the said Benjamin Cheverton, shall cause a particular description of the
nature of my said Invention, and in what manner the same is to be performed
to be inrolled in Her said Majesty's High Court of Chancery within six
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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Benjamin Cheverton, do hereby declare that the nature of my said Inven-
tion, and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, reference being had
to the Drawings hereunto annexed, and to the figures and letters marked
thereon, that is to say:-
My improvements relate to that description of machinery for cutting, sawing,
and slicing wood, ivory, and other materials in which the saw or other cutting
tool is to be moved, either by an alternating rectilineal or by an alternating
curvilineal motion. They comprize several particulars applicable more or less
separately and jointly to two cases; the first, when the material is cut so thin,
being at the same time sufficiently elastic as to allow it to bend away from the
cutting tool and permit the latter to be much thicker at its back or other part
than at its cutting edge; the second, when the cutting tool, which in this in-
stance is always a saw, is not thicker at any part, although it may be thinner
than at its cutting edge.
I will first state those improvements which are common to both cases, pre-
mising that my object is by making more perfect arrangements to render the
present operations of sawing and slicing more exact and certain in their results,
thereby enabling them to be wrought on materials of greater dimensions than
usual, and in the case of sawing, with less waste in sawdust, and also thereby
allowing a greater number of similar operations to be carried on at the same
time, and with greater rapidity.
My first improvement under this head consists in arrangements to avoid
the concussion, vibration, and oblique strain to which the moving frame
carrying the sawing or slicing tool or tools is now subject, in consequence
of its being through the connecting rod united immediately with the crank;
I therefore introduce a distinct frame, with a cross head moving with a
parallel motion therein, to sustain the oblique strain from the crank. I
isolate this frame as much as possible from all the other parts of the machine,
and I make the connection from the cross head to the moving frame by
means of a spring connecting rod, having at each end a ball and socket
joint, and I further cut off all hard unyielding metallic communication between
the crank and moving frame, and consequently almost all concussion and vibra-
tion, by making the sockets to the said balls of an elastic packing.
My second improvement under this head consists in an arrangement to avoid
the excessive agitation and shaking produced by an unbalanced centrifugal force
in the fly wheel, in consequence of the usual practice of loading it on one side to
counterpoise the weight of the moving frame. I therefore suspend the frame

page_text: through the medium of springs of any description, or through the medium of
elastic fluids, such as gas, air, or steam; or I accomplish the same purpose,
though not with so smooth or so equable an action, by fixing a working steam
cylinder over the moving frame, actuating it immediately therefrom, and placing
a crank and fly wheel in connection with it below. If I adopt this mode, I
equalize the steam power as much as possible to the different resistances in the
up and down strokes by imparting only a single action to the piston if the
difference is considerable, or when using a double action, by wire-drawing the
steam more or less on one side through the slide valve, or by having the piston
rod larger than usual. The mode of adjustment is determined by the weight
of the frame and the force of the steam. When the frame works horizontally,
this improvement does not of course apply.
Proceeding now to the first case, that is, when the material is cut
very thin, and the cutting tool is much thicker elsewhere than it is at
its cutting edge, my first improvement applies to sawing and relates to
straight-edged or slightly curvilineal-edged saws. It consists in combining
thin-edged thick saws, whether formed of thin saw blades attached to
thick backs, or of thick saw blades, each ground to a thin edge, and with or
without backs, and whether used singly or several together, with the use of a
sliding or moving carriage with a transverse motion, and capable by its own
proper motion of carrying, directing, and guiding the material in reference to
the saw or saws, of pressing it against the edge or edges of the saw or saws, and
of apportioning successively the thickness of the sheets to be cut. A form of
such carriage is now employed in combination with the circular vencer saw,
and would be suitable to be used in combination with the kind of saw now
described, altering only the mode of what is technically called feeding the saws,
which may be that which is adopted in those saw mills, which, using the
alternating rectilineal motion, cut both with the up and the down strokes. For
the sake of brevity and perspicuity, I will hereafter give the name of bevel
saws to this kind of saw, however they may be shaped or constructed so that
they are thicker at any part than they are at their cutting edges, but under-
standing always that I refer to straight or slightly curvilineal-edged saws. I
prefer thick to thin bladed saws, and I prefer to make the edges of the saws in
respect to their sides of a plano-concave form, making it slightly more acute
than the angle at which the sawed sheet of the material can be conveniently
bent from the log or block that is cut. I prefer also that the saw blades shall
be at least one-eighth of an inch thick, and I prefer to strengthen them by
screwing or otherwise fastening them on to angle irons, the sides of which are
perpendicular to each other, but in such a manner that they may be advanced

page_text: forward as their edges are worn away. I would state that thin-edged thick
saws have before been used, but not combined with the use of a traversing
carriage, therefore I do not claim construction of this kind of saw separately,
nor the traversing carriage separately. Another improvement under this
head is applicable to the said bevel saws, and consists in grinding the sides
which terminate in the cutting edge in the place which the saw or saws
occupy in the machine, and by means of the usual working motion of the
machine, the grinder being stationary or moving at pleasure, whereby a
perfect parallelism with the plane of motion is obtained. The further part
of this improvement consists in combining with the said motion of the
saw or saws the use of the two motions at right angles with each other be-
longing to the moving carriage, by imparting them as they are required to
the grinder, by means of the frame carrying the grinder being attached to
the said carriage, whereby a perfect parallelism with the motion of the said
carriage is also obtained. The best form of grinder is that of a cylinder, to
which a rotary motion should be given, and its length should be that of the
working part of the saw, minus the length of the stroke.
My third improvement under this head applies to sawing and slicing, and
consists in arranging in one frame a series of such saws or of knives in parallel
lines, distant from each other the thickness of the saw-kerf and the intended
thickness of the veneers, but following each other at such distance apart as
will admit the veneers to be bent easily out of the way; I am thus enabled to
cut several sheets or veneers at the same time.
My fourth improvement under this head applies to the kind of saw herein
described, and consists in making the spaces between the teeth of the saw so
deep as to allow the sawdust to pass continually away, escaping sideways from
the bottom of these spaces into the interval between the saw blade and the
veneer when the latter is bent away from the former. The improvement
further consists in making the cutting edges separate for each stroke, giving to
each tooth of the saw two distinct edges to cut in opposite directions, each
edge delivering its sawdust into the same space. These arrangements will be
found very useful, particularly when cutting veneers from wide logs of wood;
and of a greater depth than the stroke of the saws, inasmuch as they enable me
even in these cases to place the edge of each saw parallel to the motion of the
saw frame, and to operate both in the upward and downward strokes.
In reference to the second case or head under which I have stated my im-
provements, that is, when the saw is in no part thicker than at its cutting edge,
my first improvement consists in connecting a series of saws at each end with
a frame, so that by any mechanical drawing of one or both frames, all the saws

page_text: may be drawn and strained at the same time, whereby I am enabled to approach
the saws more closely to each other than when, according to the usual practice,
they are separately strained, and, indeed, to place them at any the smallest
distance apart. This improvement further consists in attaching the saws to the
frames by means of notches cut in their edges, as will be seen in the Drawings.
I prefer to fix one of the frames and strain the other. by means of screws.
My second improvement consists in employing the differential kind of
screw for drawing the frames, by which it can be done with greater power
and facility.
Another of my improvements consists in a mode of combining a series of
stretched saws for cutting veneers with a traversing carriage.
I will now give an illustration of the nature of these improvements, and
show how they may be carried into effect by putting them into a form for prac-
tical use; but I do not confine myself to the details, as they may be varied
without departing from the peculiar character of the improvements. I will
also exemplify all of them in one machine, although I think it will be better in
practice to have separate machines for the different uses. The same letters
and figures of reference will apply to the same parts in all the Drawings. The
scale is generally one inch to the foot, but for a few parts three inches to the
foot.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a back view of a sawing machine, and, on occasion, a slicing
machine. A is the fly wheel; B, the loose and fixed pullies; C, the driving
belt; D, the crank; E, the connecting rod; F, the cross head; G, its ball
and socket joint; H, the spring connecting rod, with a bridle in the middle to
regulate the extent of the springing of the blades. A certain curvature is
given them, which momentarily at the turning of the dead points is lessened or
increased. I is the upper ball and socket joint, seen better on a larger scale
at Figure 3. The top and bottom recesses contain an elastic packing, for
which Brockedon's patent stoppers answer very well. The compression can
be carried to any desired extent by adding more packing, and screwing the
caps firm to their bearings. K is the guide frame, fixed to the bed of the
moving carriage, or sliding portions of the machine that carry the log of wood
to be cut. (It is not necessary to describe that part of the machine, or to
exhibit it further than is required to show its connection with my improve-
ments, for it is the same in every essential point with what is employed in the
common circular saw veneer machine.) L, stone beams to assist in supporting
the guide frame; M, the saw frame, sliding between right angled guide bars,

page_text: cast with the guide frame; N, four bevel veneer saws, having angle irons, to
which they are attached, in the manner seen at Figures 4, 7, and 8. The
screws pass through slots in the saw blade, having their edges bevel to allow
the heads of the screws to lie flush with the plane surface of the blade. The
peculiar form of the teeth is shown in this Figure (1), also in Figure 4. Their
distance apart is not material; it may be about three-quarters of an inch.
O, the brasses with their screws, six to each, three acting on one face and
three on the other, the middle screw fixing the brass at the position to which
the other two have advanced it; P, the rollers to bend the veneers away from
the saws, and relieve them from friction. The action both of the roller and
the saw is shown on a larger scale at Figure 7, on which Q is the log of wood,
and R, the veneer; S, the steam cylinder; and T, stay rods to the wall, shewn
in section. Fig. 2 is a side view of the machine, but with a portion of the
guide frame removed to shew the saw frame, of which the upper part is in
section through the line a, b, on the plan, Figure 6, and the middle in section,
a little in advance to show the position of one of the rollers P. Another
section is given in Figure 10 to show the position and fixing of one of the
angle-iron saw N. In this view are seen an upper and lower head project-
ing from the saw frame, and braced to it with diagonal straining rods U, to
carry another set of thin-bladed saws to cut timber into boards and veneers,
showing that the same machine may be used with different sets of saws.
The position of six of these saws is represented by the dotted lines V, and
the seventh line gives the position, the position of the edge of the first angle-
iron saw shewing that the former set can act without removing the latter.
Figure 4 gives a front view of the upper head, and Figure 5 front and top
sections of the same, by which it is seen that the saws are attached by notches
on their edges to a frame W, drawn up by the screws X, and regulated and
fixed as to position by the screws Y, and that the saws are adjusted as to
intervals in the frame by the packing pieces Z, and fixed there by screws c.
The lower frame is fixed by the screws X, and the set is removed altogether
to be re-adjusted for other intervals apart, or to be replaced by another set.
In Figure 11 is seen on a larger scale the mode of drawing up the frame by
differential screws. Each screw has two sets of threads, the upper about
twelve, and the lower about ten to the inch. The frame is represented as
being first drawn tight by the nuts, which, being held by the wrench, it is
further strained by turning the screws; if these descend one inch they bring
up the frame one-fifth of an inch. The stress thrown upon the saw frame by
this set of saws is counter-strained by the screwed rods d. In this view
(Figure 2) the slide valve of the steam cylinder is seen to be fixed, but

page_text: capable of regulation by a screw. In all other respects the arrangement is
exactly the same as for a steam engine, and may indeed be used as such by
throwing off the lover of the slide valve, and actuating the latter by tappets, or
by an excentric from the shaft below. By fixing the slide in the proper
position, the steam is wire-drawn if necessary, and is admitted only on the
under side of the piston to support the weight of the saw frame; on the
descending stroke it is forced back into the boiler of the steam engine.
Any accumulation of water above the piston is discharged through the
eduction pipe, and through the small pipe e, communicating with the
pipe from the boiler; the same is cleared from the bottom of the cylinder.
Figure 6 is a plan of the machine, with a horizontal section of the guide
and saw frames through the line f, g, in Figure 1. Figures 8 and 9 give
a plan and view of the mode of grinding the knives or saws, as the case
may be, by a cylinder of cast iron or other material, and using emery or
other grinding matter. h is the cylinder, attached, as occasion requires, to
the transverse sliding carriage of the machine, by which the two traversing
motions of the carriage can be given to it. A rotary motion is imparted
by a cord or gut from the groove in the middle of the cylinder, led away
by pullies to any first mover, whilst at the same time a slow motion is given
to the frame carrying the saws or knives. The position represented is
that for grinding the plane surface, and the dotted lines shew how the
grinder may be applied to the concave or inner surface. The parts of the
Drawing in red ink shew a mode of feeding or moving the material to be
cut up to the saws, that may be adopted, but to which I make no claim. i is
an excentric; k, a connecting rod to lever 1, with two arms, working the palls
m, and driving the ratchet wheel n on the shaft o, which shaft drives, through
the intervention of the toothed gear p, the rack r, attached to the traversing
carriage 3. It will be seen, from this description of the machine, that it may
at pleasure be used to saw veneers, to saw boards, or to slice any materials that
may admit of being so treated. For the latter purpose, it is only required to
give the blades of the angle irons a knife-cutting instead of a serrated edge.
It will also be seen, that although I saw and slice both with the up and the
down strokes, the machine is capable of acting with either, requiring only the
inclination of the cutting edge to be altered from the perpendicular. It will
be further seen that a slight curvilineal motion may be given to the saw frame
in the plane of the cutting edges by making the inner faces of the guides
concentric with a distant centre; and it will be seen that I can use a vacuum
above the piston of the cylinder to suspend the saw frame, either separately or
jointly, with the admission of steam below the piston. It will be also seen

page_text: also that I can apply springs of any material or form to suspend the moving
frame, and particularly a set of spiral springs, which, enclosed in a pipe, may
descend into the pit by the side of the fly wheel, and their upper ends being
connected together, their united force may be conveyed, by ropes or bands of
any kind, to a point immediately over the moving frame, by which arrange-
ment the weight of the springs would assist their elastic force.
Having thus stated and described the nature of my Invention, I would wish
it to be understood that I do not claim the various parts herein shewn and
described separately, and the details may be varied without departing from my
Invention; and I would wish it to be understood that what I claim as my
Invention is,
First, the mode of arranging and combining saw frames in respect to the
power which gives motion to them, and the force which balances them, whereby
saw frames are moved by elastic connections, and the saw frames are counter-
balanced by elastic means, as herein explained.
Secondly, I claim the combining the herein-described bevel saws with the
use of a traversing carriage, for the purpose of cutting veneers.
I also claim the mode of applying apparatus for grinding the sides of bevil
saw's by their own motion and whilst in their places, and combining the same
with the traversing carriage as a means thereto, as herein described.
And I also claim the combination of several bevel saws or of several knives
in the same frame, whereby several cuts may be simultaneously made.
I also claim the mode of forming the teeth of the saws conjointly with
spaces between them, as herein described, so that the saws may cut in opposite
directions.
I also claim the mode of straining several saws simultaneously, by having
notches or recesses at the back and front of each saw, combined with the means
herein described.
And, lastly, I claim the so combining a series of thin saws placed laterally
in respect to the plane of motion of the saw frame, with the use of a
traversing carriage placed parallel to and moving in its longitudinal direction
parallel with the plane of motion of the saw frames, whereby several series of
veneers may successively be cut from the same log.
.
In witness whereof, I, the said Benjamin Cheverton, have hereunto set
my hand and seal, this Sixteenth day of July, in the year of our Lord
One thousand eight hundred and forty-four.
BENJ (L.S.) CHEVERTON.

page_text: AND BE IT REMEMBERED, that on the Sixteenth day of July, in the
year of our Lord 1844, the aforesaid Benjamin Cheverton came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, 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.
Enrolled the Sixteenth day of July, in the year of our Lord One thousand
eight hundred and forty-four.