IMPROVEMENTS IN CUTTING OR REDUCING WOOD AND OTHER SUBSTANCES
Year: 1853

page_text: LETTERS PATENT to John McDowall. of Walkinshaw Foundry.
Johnstone, in the County of Renfrew, North Britain, Engineer,
for the Invention of "IMPROVEMENTS IN CUTTING OR REDUCING WOOD
AND OTHER SUBSTANCES."
Johnstone, in the County of Renfrew, North Britain, Engineer,
for the Invention of "IMPROVEMENTS IN CUTTING OR REDUCING WOOD
AND OTHER SUBSTANCES."
Sealed the 28th March 1853, and dated the 12th January 1853.
PROVISIONAL SPECIFICATION left by the said John McDowall:
at the Office of the Commissioners of Patents, with his Petition,
on the 12th January 1853.
I, JOHN MCDOWALL, of Walkinshaw Foundry, Johnstone, in the
County of Renfrew, North Britain, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN CUTTING OR REDUCING
WOOD AND OTHER SUBSTANCES " to be as follows:-
This Invention relates to certain mechanical arrangements connected
with wood cutting machinery, such as sawing and planing machines,
having for their object the improvement of the feed action of such
machinery, combined with a simplification of the details, together with
the obtainment of a more efficient and satisfactory cutting action than
has been hitherto used. The improved feed motion, in its application
to the feeding of the timber up to the saw in sawing machinery, is in part
a modification of Mr. McDowall's original "silent feed motion," patented

page_text: in the year 1852. Instead of the ordinary ratchet wheel with detents
and catches, a plain rim pulley, with both its internal and external
surfaces smoothly turned, is used, being set fast on the shaft communi-
cating with the gearing for carrying forward the timber to be cut.
This plain wheel is urged round by periodical movements derived from
a vibrating rod in connection with the saw machinery in the usual
way, the end of this rod being jointed by an eye to the ends of a pair
of short parallel link pieces set one on each side of the pulley rim.
These link pieces are also formed with eyes at their opposite ends to
receive the studs of a pair of segmental friction pieces, one on each
side, fitting to the interior rim surface, whilst a pair of intermediate
eyes carry a single external friction or saddle piece, bearing on the
external periphery of the pulley. These friction pieces thus embrace
the pulley rim and grip, or retain firm hold thereof, during one traverse
of the actuating rod on the upper ends of the two links, owing to the
angular position of the latter due to the pull of the rod; whilst in the
reverse action the friction pieces at once relax their hold, and slide
back silently. This is the actuating motion; and a similar contrivance
is adapted for the detent stop to hold the pulley during the reverse
disengagement of the actuating details. This detent is suspended from
a fixed centre, and, like the actuating apparatus, it has an adjusting
hand wheel for working a screw spindle to bring up a stop on the
external saddle piece, so as to bear against the parallel links, and
prevent the angular gripping action when it is to be thrown out of
gear. A helical spring is also fitted to the apparatus in both cases, to
bear up
the 'parts into contact, whether tight or slack, and thus prevent
chattering, and secure a noiseless action; whilst the contact so produced
causes an instantaneous action on the reversing of the actuating motion,
as the working surfaces are thus kept well up in action. The action
of this apparatus is perfectly smooth, and it may be adjusted to give
excessively minute increments of feed in a very simple manner. The
sane general principle of traversing grip or hold is also suitable for
carrying forward the timber to the cut either in sawing or planing
machines under another form. As adapted for this purpose, the usual
nipping rollers ordinarily used to embrace the timber on each side are

page_text: totally dispensed with, and two or more silent nippers on the principle
already described are substituted for them and their complicated gear-
ing. These nipping traversers consist of a pair or niore of vibrating
frames embracing the timber, and having upper and lower friction
clipping pieces adjustable to take in various thicknesses of material.
These two frames are actuated differentially by an arrangement of four
elliptical spur wheels, geared in such a way that there shall always be
one or more friction traversers in action at any given time, so as to keep
up a constant and uniform silent traverse without any injury to the
timber from rolling compression. The elliptical wheel arrangement
also provides for the slow and uniform traverse forward of the timber,
with a quick return stroke when the clipping apparatus is disengaged.
To obtain a more efficient and accurate cutting action in planing or
shaping timber, a species of "roughing cutter" is used in advance of
the finishing and thicknessing tools. This rougher may be either on
the principle of the saw, or it may be a combination of small revolving
cutters, which shall cut away the timber surface in shallow strips, so
that when the main cutters come to act there may be less risk of these
latter cutters carrying away or tearing off large areas of the material.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John McDowall in the Great Seal Patent Office
on the 12th July 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 'I,
JOHN MCDOWALL, of Walkinshaw Foundry, Johnstone, in the County
of Renfrew, North Britain, Engineer, send grecting.
:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of January, in the year
of our Lord One thousand cight hundred and fifty-three, in the six-
teenth 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 assigns, should at any time agree with, and 'no

page_text: 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
CUTTING OR REDUCING WOOD OR OTHER SUBSTANCES," upon the condition
(amongst others) that I, the said John McDowall, by an instrument
in writing under my hand and seal, 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 I, the said John Me Dowall, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:
My said Invention relates to certain mechanical arrangements con-
nected with wood cutting machinery, such as sawing and planing
machines, having for their object the improvement of the feed action of
such machinery, combined with a simplification of the details, together
with the obtainment of a more efficient and satisfactory cutting action
than has been hitherto used. The improved feed motion, in its application
to the feeding of the timber up to the saw in sawing machinery, is
in part a modification of my original "silent feed motion," for which
Letters Patent were granted to me in the year One thousand eight
hundred and fifty-two. Instead of the ordinary ratchet wheel with
detents and catches, a plain rim pulley, with both its internal and ex-
'ternal surfaces smoothly turned, is used, this pulley being set fast on
the shaft communicating with the gearing for carrying forward the
timber to the cut. This plain wheel is urged round by periodical
movements derived from a vibrating rod in connection with the saw
machinery in the usual way, the end of this rod being jointed by an
eye to the ends of a pair of short parallel link pieces, set one on each
side of the pulley rim. These link pieces are also formed with eyes at

page_text: their opposite ends to receive the studs of a pair of segmental friction
pieces, one on each side, fitting to the interior rim surface, whilst a pair
of intermediate eyes carry a single external friction or saddle piece,
bearing on the external periphery of the pulley. These friction pieces
thus embrace the pulley rim and grip, or retain firm hold thereof during
one traverse of the actuating rod on the upper ends of the two links,
owing to the angular position of the latter, due to the pull of the rod;
whilst in the reverse action the friction pieces at once relax their hold,
and slide back silently. This is the actuating motion; and a similar
contrivance is adapted for the detent stop to hold the pulley during the
reverse disengagement of the actuating details. This detent is sus-
pended from a fixed centre, and, like the actuating apparatus, it has an
adjusting hand wheel for working a screw spindle to bring up a stop on
the external saddle piece, so as to bear against the parallel links, and
prevent the angular gripping action when it is to be thrown out of
gear. A helical spring is also fitted to the apparatus in both cases, to
bear up the parts into contact, whether tight or slack, and thus prevent
chattering, and secure a noiseless action; whilst the contact so pro-
duced causes an instantaneous action on the reversing of the actuating
motion, as the working surfaces are thus kept well up in action. The
nction of this apparatus is perfectly smooth, and it may be adjusted to
give excessively minute increments of feed in a very simple manner.
The same general principle of traversing grip or hold is also suitable
for carrying forward the timber to the cut, either in sawing or planing
machines under another forin. As adapted for this purpose, the usual
nipping rollers ordinarily used to embrace the timber on each side are
totally dispensed with, and two or more silent nippers, on the principle
already described, are substituted for them and their complicated gear-
ing. These nipping traversers consist of a pair or more of vibrating
frames embracing the timber, and having upper and lower friction
clipping pieces adjustable to take in various thicknesses of material.
These two frames are actuated differentially by an arrangement of four
elliptical spur wheels, geared in such a way that there shall always be one
or more friction traversers in action at any given time, so as to keep up a
constant and uniform silent traverse without any injury to the timber

page_text: from rolling compression. The elliptical wheel arrangement also
provides for the slow 'and uniform traverse forward of the timber, .with
a quick return stroke when the clipping apparatus is disengaged. To
obtain a more efficient and accurate cutting action in planing or
shaping timber, a species of roughing cutter "is used in advance of the!
finishing and thicknessing tools. This rougher may be either on the
principle of the saw, or it may be a combination of small revolving
cutters, which shall cut away the timber surface in shallow strips, so
that when the main cutters come to act there may be less risk of these
latter cutters carrying away or tearing off large areas of the material.
Or instead of this arrangement, the roughing and finishing cutters may
be continued in a single cutter or tool.
Figure 1, on Sheet 1, of my Drawings, is a complete side or longitu-
dinal elevation of my improved planing machine in working order, with
a-board in the act of passing through it to be planed. Figure 2, is a
corresponding plan of the machine:
Figure 1, on Sheet' 2, is a longitudinal section of a portion of the
same machine, furnishing a side elevation of my differential or con-
tinuous working silent feed motion for feeding up the timber to the
cut; Figure 2, is an end elevation of the feeding nippers and adjusting
movement corresponding; Figure 3, is a detailed elevation, on a larger
scale, of the compound roughing and finishing cutter or rotatory planer.;
Figure 4, is a corresponding end view of this cutter; Figure 5, is an
elevation of my rotatorv roughing planing cutter; Figure, 6 is an end
view corresponding; and Figure 7, is a longitudinal elevation of the
cutter at right angles to Figure 5; Figure 8, is a detailed side elevation
of my silent feed motion as worked by elliptical wheels and arranged for
sawing machines where a differential traverse is necessary; Figure 9, is
an end elevation of the same parts corresponding; Figure 10, is a side
view of my improved modification of silent "feed motion," with a
smooth rim pulley and noiseless sliding and holding catch and detent.
-The entire apparatus of the planing machine is carried upon the
two long main vertical side standards A, cast in suitable lengths,
and bolted down to the foundation by lugs, as at B. These frames
are connected together by transverse end. pieces and tie rods to

page_text: form a strong rectangular carrying frame, and at one end of it.
is, the first motion driving shaft C, shown as broken away from its
actuating power. This shaft has an inner end bearing in one of the
side standards, and it carries the large first motion strap pulley D,
giving motion to the whole of the cutting movements. From this pulley
a broad open strap E, passes to a small pulley F, on the outer end of
a cross shaft G, running in bearing brackets H, bolted to the framing
at the opposite end of the machine. This shaft also carries an outside
pulley I, from which a crossed strap J, passes back to a small pulley K,
on the shaft of the compound rotatory planing cutter L, for planing
the upper surface of the board or flooring deal M. The spindle of this
cutter is carried in vertically adjustable end bearings N, fitted to the
vertical edges of the bracket standards O, which are bolted down on
the upper edges of the main framing pieces. The cross shaft G, also
carries a pair of equal sized strap pulleys P, whence twisted straps Q
passes to the two broad pulleys R, on the vertical spindles of the two
cutter heads S, which cut the edges of the wood, and, if necessary,
tongue and groove them. These two latter cutter spindles are carried
in bearings T, on horizontal dovetail slide picces U, adjustable. at dif- C
ferent distances on each side the longitudinal centre of the machine
by the action of two screw spindles, one of which is actuated by the
outside hand wheel V; whilst the other spindle, which is only to be
shifted occasionally, is adjustable by a key to be shipped on to the..
square head W, on the opposite side of the machine. The front spindle
carries a fine pitched worm X, in gear with a horizontal worm wheel Y,.
fast on the spindle of a small index hand which points to a graduated
are Z, and thus indicates the exact set of the cutters for tho particular-
breadth of timber under treatment.
As the deal is passed into the machine to be planed, it is first of all,
entered beneath the nipping feed cams a, which carry it continuously
forward to the cut. Each nipping arrangement consists of a horizontal:
traversing plate of metal b, tongued at at its opposite ends to slide freely.i
but accurately in corresponding grooves in the top plates c, of the stan-
dards; and upon these plates c, are attached a pair of vertical parallel.
standards d, connected at their upper ends by a light cross bar e, which,

page_text: answers as well for the beaings of the over head cross adjusting spindlef,
for the "set" of the nippers. Each standard d, is slotted down its centre, to
receive and guide the traversing nut bearings g, of the cross cam spindle
h, a screw spindle i, being passed down from above and through the nuts
g, so as to enable the cam spindles h, to be set up or down by the screw
action. This screw action is worked, when necessary, by handles shipped
on the end of the cross spindle f, by the workman, who thus works the
screws simultaneously through the two pairs of small bevil wheels g.
Each cam spindle h, has an eccentric cam a, loosely hung upon it by an
eye, the cam eye being entered upon the spindle up against an adjustable
collar k, on the latter; and the cam spindle h, is set fast in the
standard slot by the outside adjusting nut l. Thus arranged, the
nipper forms a complete traversing frame capable of free horizontal
movement along its guide grooves. Beneath the level of its traverse
support two projecting eye picces m, are cast on the plate b, each eye
carrying a joint stud n, whence short links o, pass to corresponding
eyes b, on the upper ends of the two sides of the vibrating lever frame
pieces q. Each frame is carried on a stud centre r, in the framing,
and each has a bottom joint eye s, for connection by a link rod t, to
the actuating cam feed mechanism at the front or entering end of the
machine. Each frame has also a heavily weighted bent lever u, attached
to its bottom cross bar, and contrived so as to tend to draw the frame
continually backward in the opposite direction to the traverse of the wood.
The primary movement is given to the entire series of these nipping
feeders, of which there are six altogether, three being at each end of
the machine, by a toothed pinion v, on the first motion shaft. This
pinion gears with a larger toothed wheel w, set on a cross shaft a, and
carrying a second pinion y, in gear with a second spur wheels, fast on
the actuating cam shaft 4. On this shaft are keyed the three separate
cams or differential eccentric pieces 1, 2, 3. Opposite to and over the
periphery of each cam is set an anti-friction pulley 5, carried on the
horizontal arm of a bell crank lever 6, the three bell cranks being carried
loosely on a stud shaft 7. The longer vertical arms of these bell cranks
are connected by eyes 8, at their lower ends to the respective rods t,
which are severally linked, as already described, by end and intermediate

page_text: eyes to the bottom of each of the nipping frames. The three cams are so
set at starting that they shall each act at different periods of the revo-
lution of their carrying shaft in such manner that an uniform feed action
may be given to the board passing through the machine. In other terms,
they are set at equal distances asunder in the direction of revolution of
their shaft, each cam being linked to and made to actuate two nippers.
Thus the corresponding nippers of each pair have always the same rela-
tive position, as marked 1, 2, and 3. Then as the planing goes on, and
the cams revolve, each pair of nippers is made to traverse forward, say
in the direction of the arrows at 1, by the upward revolving action of
the corresponding cam. This forward traverse is the positive feed
action, for the moment the nipping franie moves in this direction the
prominent eccentric portions of the cams 1, are thereby forcibly
carried down or jammed hard upon the upper surface of the timber,
squeezing it firm down upon the bottom plates b, so that the timber is
carried forward to the cut, as if it were permanently attached to the
nipping feed frame. Whilst this positive feed is being given to the
wood, the two pairs 2, of the nippers are being brought back by the
action of their weighted levers, as their corresponding cam is descending
in its revolution. These two nippers are consequently slipping over the
wood, for on the instant of the return movement towards the entering
end of the machine the prominences of the nipping cams are drawn out
of nipping contact, and the frames go back without interfering with
the feed traverse of the wood in the forward direction. As delineated
in my Drawings, the third pair of nippers are still in forward gear, and
acting by reason of the position of their actuating cams to carry forward
the wood in concert with the nippers 1. By this means, as each cam
comes round it gives its forward feed and back traverse in regular
uniform succession, each succceding nipper gradually relieving the last
in feeding action. And although two nippers always thus tend to comic
into action at the same time, derangement cannot ensue from this cause,
inasmuch as the quickest forward feeding nippers, at any given moment,
carry forward the wood free of the other nippers, which give way in
their nipping action to the higher rate of motion, by reason of the con-
sequent slip or disengagement of the nipping cam, on the principle

page_text: which I have already described. In this way the feed is constantly
uniform, as, although it is furnished by three separate actions, yet each
only comes into actual feeding play at the moment that it is required to
keep up the regularity of movement. As the board is thus carried for-
ward it comes first above the three finishing planes in the frame 9, over
which it is held down by the three rollers 10, which run in adjustable
bearings, held down by the helical springs 11, adjustable to any desired
tensional pressure by the nuts 12, on their screwed spindles 13, carried
in the stationary frames 14. After passing these pressers, the emerging
end of the wood, as planed and finished on its under surface, proceeds
beneath the duplex pressing pulleys 15, set on a stud centre in the free
end of a lever arm 16, fast to the horizontal shaft 17, carried in end
bearings 18, in the frame, and held down by the lever and weight 19.
Thence it enters beneath the pair of horizontal pressing rollers 20,
similarly held down by adjustable helices 21, and it is between these two
rollers that the planing of the upper surface takes place; at the moment,
however, of its passage beneath the duplex pulley 15, it is first acted upon
by the two cutting heads S. In the present' example, these cutters
arranged for tongueing and grooving the opposite edges of the flooring
deal, as is usual in laying flooring. Thus in the elevation Figure 1, tlie
two square cutters 22, take off the two angles of one edge of the deal,
leaving the central feather or tongue standing up, whilst the other double
angular single cutter 23, takes off the sharp angles from the tongue.
Again, the opposite cutter head for the other side carries three plain cen-
tral grooving cutters 24, for producing the plain groove, whilst a fourth
duplex cutter 25, is added to shave off the angular edges in a similar
way. This completes the edge finish of the board, and the latter then
being held well down by the rollers 20, is submitted to the action of
the rotatory cutter or "thicknesser" L, for bringing the upper side of
the wood to a fair level, and equalising the thickness of the deal. This
cutter, which both rough cuts and smooths off, consists of a stout spindle
26, having a squared or rectangular central portion 27, with a
longitudinal dovetail groove 28, on each side, to receive the dovetail
heads of the adjusting bolts 29, for holding the two cutter plates 30.
Each of these plates is cut or slotted out transversely like a comb, so as to

page_text: orm a series of regularly disposed cutters; and the two plates being
precisely similar they are so set on their spindle that they shall "break
joint," as it were, in their action upon the deal. In other words, as one
cutter comes round it cuts out a series of strips of wood, corresponding.
to the size and arrangement of the cutting edges, whilst the other or
succeeding cutter then comes into action, and takes off the prominent.
strips left
the first one; and in order that a clean smooth cut may be
made, the relative cuts of the two cutters are made to overlap slightly
in their cutting action. With this arrangement of cutter, the whole of the
cutting edges may be accurately ground up and sharpened at one oper-
ation; and one setting of the plate, by means of the dovetail bolts, which
pass from the slots in the spindle through slots in the plate, sets the
whole range of cutters. The cutter shewn in Figures 5, 6, and 7, is a -
"rougher" only. The spindle is carried in a similar way, but it is
slotted clear through its central rectangular portion to receive the alter-
nated roughing cutters A, B, which are put in in directions reverse to..
each other, so as to present cutting edges in opposite sides alternately,
the series being spaced out by intermediate guage or setting pieces.
The spindle is bored out at one end to receive the adjusting binding
screw C, by which the whole of the cutters may be screwed hard up
against the solid end of the holding slot. This affords facility of ad-
justinent of the cutters to suit various purposes, and the effect is, that, in;
working, the cutters remove the over wood or rough surface in shallow
strips, so that when the finishing cutter follows it makes a clean smooth
surface with little difficulty, and there is less liability to tear out large
areas of the wood from the surface. After leaving the cutter L, in the
machine, the deal is in its finished state, and it has then simply to be:
drawn completely through by the nipper arrangement, when it is de-
livered in its planed state. In the detailed side elevation of my silent
feed motion, Figures 8, and 9, the general arrangement already described
is. here used also, but it is modified for sawing purposes. The deal A,..
in its passage up to the cutting action, is nipped between the two clipping.
pieces B, just as between the cam and bottom cross plate already referred
to, the upper clipping piece being adjustable at pleasure by the handle
and screw c. The actuating shaft is at D, carrying two elliptical spur!
.
.

page_text: of the nipping frame having
wheels E, which gear with corresponding wheels F, on the second
motion shafts G. On these shafts are two opposite cranks II, from which
connecting rods I, pass to the vibrating levers J, of the nippers. The
constant uniform revolution of the shaft D, thus gives a differential
action to the two frames, by reason of the varying leverage of the
elliptical wheels. This is specially suited for sawing, as the wheels are
so set in reference to the sawing action that the deal has a slow forward
traverse into cut, whilst the nipper itself returns at a rapid rate, the
nipping and slipping action of the feeders being effected simply by the
corresponding traverse of the frames. For instance, in Figure 8, the
nipper next the elliptical wheels is in feeding action, for as each clipping
piece B, is jointed at its centro to its carrying frame, which embraces
the deal, it follows that when the traverse takes place in the direction
of the arrow the resulting angle of the frame, due to the drawing for-
ward of its lower end, brings the two clippers B, into closer contiguity,
and thus causes them to nip the deal A. On the other hand, the other
nipper is returning freely, the lower end
been brought up against the stop K, when the vertical position of the
frame separates the nippers. In this detail two nippers only are shewn,
but it is obvious that a greater number may be employed, the series
being so set in relation to each other that the deal may have a constant
uniformi traverse up into cut. The substitute for the ordinary ratchet
wheel, Figure 10, consists of a rim pulley A, set fast on a shaft B, in gear
with the feed action for traversing the log up to the saw. It is turned
by the reciprocatory action of the rod C, which is jointed at D, to the
pair of parallel links E. Near the other ends of these links are two eyes
F, carrying stud centres for the saddle pieces G, two inside and one out
of the rim of the pulley. This is the actuating motion. The detent or
stop is at H. It is suspended from the fixed centre I, and it has an
adjusting hand wheel J, like the wheel K, in the actuating detent, for
working a screw spindle L, to bring up stops M, on the respective ex-
ternal saddle pieces N, G, so as to bear against the parallel links E, O,
and prevent the angular gripping action when the feed is to be stopped.
The actuating nipper has a helical spring P, or other elastic bearing, to
keep the parts in contact, and prevent chattering, and keep up an in-

page_text: stantaneous action on reversing. It will be obvious to the practical man
that this movement acts in the same way as the feeders already described,
for when the stop M of the actuating detent is relieved from the links
E, the traverse of the rod C in the direction of the arrow brings about
the necessary nipping action upon the inner and outer surfaces of the
pulley rim, and the pulley is thus made to revolve, the detent II per-
mitting the rim to slip through it. But on the return of the rod C,
the nipping pieces G, are relieved from the rim, whilst the angular nip
of the detent saddles of H, now comes into play to hold the pulley from
going back until the next stroke.
Having 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 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 for
cutting or reducing wood and other substances, as herein-before de-
scribed.
Second, the system or mode of effecting a silent feed or traverse
motion of the wood during cutting by means of angularly worked
clipping frames or holders, as herein-before described.
Third, the application and use of self-acting eccentric cams for en-
gaging and disengaging the wood in correspondence with the back and
forward traverse of their actuating frames.
Fourth, the application of a differential system of cam or eccentric
movement for keeping up a continuous uniform feed traverse, as herein-
before described.
Fifth, the system or mode of working the nipping feed apparatus by
means of elliptical gearing for obtaining a differential action.
Sixth, the application and use of angling, clipping, or holling pieces,

page_text: whether as applied direct to the wood to be cut, or to a pulley rim for
effecting the necessary feeding movement.
'Seventh, the system or mode of obtaining a continuous noiseless feed
by means of the successive actions of self-acting engaging and dis-
engaging nippers, wherein the quickest mover takes up the feed and
disengages the slower one.
Eighth, the system or mode of constructing rotatory cutters, wherein
the narrow cutting edges or teeth are so disposed as to break joint with
each other in their cutting action.
Ninth, the system or mode of obtaining a roughing and finishing
cutting action in one cutter by means of alternated and reversed cutting
teeth or edges, each set of which removes or cuts away the wood left in
strips by the other.
Tenth, the system or mode of constructing roughing cutters by lock-
iug a series of cutters in a slotted spindle, as described in reference to
Figures 5, 6, and 7, on Sheet 2, of my Drawings..
Eleventh, the system or mode of roughing or giving the first cut to
the wood being reduced by means of cutters, which take away the wood
in narrow strips, in the manner and for the purpose herein-before
described.
In witness whereof, I, the said John McDowall, have hereunto
set my hand and seal, this Ninth day of July, in the year of our
Lord One thousand eight hundred and fifty-three.
JOHN MCDOWALL. (L. S.)