Improvements in and relating to Machinery for Cutting Boards or Veneers from a Log or Block of Wood.
Year: 1890

page_text: Date of Application, 26th Feb., 1890
Complete Specification Left, 26th Nov., 1890-Accepted, 31st Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Machinery for Cutting Boards or
Veneers from a Log or Block of Wood.
I, GUSTAV ADOLPH ONCKEN of Chicago, Illinois, United States of America,
Civil Engineer, do hereby declare the nature of this invention to be as follows :—
My invention relates to veneer and board-cutting machines and the objects of
my said invention are to provide means for obtaining under all circumstances
veneers and boards of uniform thickness throughout second, to afford facilities
for cutting wood of unequal constitution, and, third, to reduce the friction
or resistance which the presser-bar meets with from the cutting surface of the
wood.
It is frequently found that in veneer cutting machines, in which the vencer is
cut either from a rotating log, or by presenting the block to the action of a
reciprocating knife and presser-bar and in which a cutting device, having both
the knife and the presser-bar immovably attached to the knife frame is employed,
the board or veneer, cut from the block will not under all circumstances keep a
uniform thickness corresponding with the distance of the knife edge from the actual
guiding edge of the presser-bar.
This is due to the circumstance, that although the initial cut of the knife
will produce a slice of true thickness, during the further operation in consequence
of the wood being considerably softened in a steam alkali or acid bath the knife is
forced to cut into progressively increased compressed wood, so that the slice
commenced to be cut from the log will be finally prevented from passing between
the knife and the presser-bar. The slice of the wood having in spite thereof
passed the space between the knife edge and presser-bar will extend according to
the increasing pressure of the progressively advancing presser-bar and therefore
they become proportionately thicker. This of course will result in a considerable
loss of power, all parts of the machinery suffering thereby and most of the
destructions of the knives are caused by these circumstances.
To overcome this inconvenience I construct the pressure-bar in such a manner
that it may yield within certain limits determined by the hardness of the wood and
the distance from the cutting edge of the knife.
For this reason the presser-bar is attached to a moveable carrier or slide which
is guided upon the knife frame by means of rods or the like passing through
suitable sockets fixed upon the knife-frame. These rods are provided with suitable
springs the tension of which being adjustable by means of handwheels having a
female screw thread to engage with the thread on the front end of said rods and
the springs serve to elastically press the presser-bar towards the cutting edge of
the knife. The thickness of the slice to be cut from the block of wood depends
upon the tension at which the springs are adjusted, but in case of any accidental
resistances caused from the cutting and the extension of the slice cut from the
wood, the presser-bar is enabled to yield sufficiently, without in consequence of
this yielding motion, the entire lateral pressure of the wood being transmitted to
the knife.
In some cases the presser-bar is preferably guided parallel to the cutting edge
of the knife on the knife frame by the aid of a pair of rods and the tension of only
one adjustable spring transmitted by a lever mechanism upon the latter. This
arrangement, which is however partly described in the Specification of former
Letters Patent No. 15728 dated Nov. 16th 1887, is particularly adapted to cut
tapered and any other irregularly grown blocks of wood, as it enables the presser-
bar to be more exactly adjusted than by the employment of two independent

page_text: springs and to yield under all circumstances parallel to the cutting surface of the
wood.
Instead of making the said carrier or slide together with the presser-bar
yielding from one end to the other, the carrier may be fixed to the knife frame
but in this case I provide a flexible presser-bar or the like which yields in
itself, and for this reason I construct the presser-bar of a number of small parts
each of which is separately attached to the carrier and a layer of elastic material
such as india-rubber is placed between those parts of the presser-bar and the
stationary carrier of the same. But in order to reduce the resistance caused by
the friction between the wood and the presser-bar, I sometimes provide the latter
with antifriction rollers in such a manner, that only a small part of their periphery
will project beyond the presser-bar to slide over the wood.
These constructions of the presser-bar are particularly applicable in cutting
wood of unequal constitution as for instance, knotty or branchy wood as they will
advantageously prevent destruction of the cutting edge of the knife.
Dated this 26th day of February 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Machinery for Cutting Boards or
Veneers from a Log or Block of Wood.
I, GUSTAV ADOLPH ONCKEN, of Chicago, Illinois, United States of America,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
My invention relates to veneer and board cutting machines and the objects of my
said invention are, first, to provide means for obtaining under all circumstances
veneers and boards of uniform thickness throughout, second to afford facilities for
cutting wood of unequal constitution and third to reduce the friction or resistance
which the presser-bar meets with from the cutting surface of the wood.
I attain the objects of the mechanisms illustrated in the accompanying drawings,
in which,
Figure 1 is a top view partly in section of a knife frame or support or a veneer or
board cutting machine of known construction, provided with a yielding presser-bar,
showing the first part of my improvements.
Figure 2 is a similar view showing a modification.
Figure 3 is a front elevation partly in section of Figure 2.
Figure 4 a cross-section on the line X X of Figure 3.
Figure 5 illustrates a modified arrangement of the presser-bar to perform the last
parts of my invention.
Similar letters refer to similar parts throughout the several views.
It is frequently found that in veneer cutting machines, in which the veneer is
cut either from a rotating log or by presenting the block to the action of a
reciprocating knife and presser-bar and in which a cutting device, having both the
knife and the presser-bar immovably attached to the knife frame is employed, that
the board or veneer, cut from the block will not under all circumstances keep a
uniform thickness corresponding with the distance of the knife edge from the actual
guiding edge of the presser-bar. This is due to the circumstance, that although
the initial cut of the knife will produce a slice of true thickness, during the further
operation in consequence of the wood being considerably softened in a steam-alkali
or acid bath the knife is forced to cut into progressively increased compressed wood,
so that the slice to be cut from the log will be finally prevented from passing
between the knife and the presser-bar. The slice of the wood having in spite
thereof passed the space between the knife-edge and presser-bar will extend

page_text: according to the increasing pressure of the progressively advancing presser-bar and
therefore they become proportionally thicker. This of course will result in
a considerable loss of power, all parts of the machinery will suffer and most of the
wear and tear of the knives will be caused by the above-mentioned circumstances.
To overcome this inconvenience I construct the pressure-bar in such a manner
that it may yield within certain limits determined by the hardness of the wood and
the distance from the cutting edge of the knife.
h
For this reason the presser-bar / may be attached to a slide 2 guided upon a
dovetail-shaped projection c of the knife-frame and by rods ³ passing through
the sockets he fixed upon the knife-frame f
The rods are provided at their front end with screw thread upon which fit
nuts in the form of hand-wheels w¹, and behind the sockets with the
springs , which act upon the said slide 2 in such a manner that the hubs of the
hand-wheels ww are bearing constantly against the front face of the sockets h³ 16.
By these means not only the thickness of the slice to be cut but also the
tension of the springs may be regulated through the medium of the hand-
wheels we w' to that effect that the pressure-bar will automatically yield according
to the extensibility of the slice of the cut wood passing between the knife-edge and
the pressure-bar.
Instead of two springs wound around the guide-rods h³ ³, only one spring w
acting upon the slide through the medium of the levers vs and and the
rods may be employed. This arrangement is particularly adapted to cut
tapered and irregularly shaped blocks of wood, as it enables the presser-bar to be
adjusted and to yield under all circumstances parallel to the cutting edge of the
knife.
For this reason the shorter arms s s¹ of the levers vs and s¹ pivoted
respectively at and to the knife-frame fare adapted to engage with suitable
slots of the rods while the fork-shaped ends of the longer arms and v¹ of the
said levers engage between the two shoulders of the sleeve upon the screw-
spindle Between the head w and the sleeve is wound the spring w which
tends to shift the sleeve towards the hand-wheel and thereby to turn the
levers vs and s about their pivots for transmitting the tension of the spring w
upon the slide 2 and the pressure-bar h. By these means the latter is permanently
and elastically moved towards the cutting edge of the knife until the rear face of
the hubs of the hand-wheels upon the threaded ends of the guide-rods 4³ /*
bear against the sockets and the tension of the spring was well as the thickness
of the slice to be cut is regulated by turning the screw-spindle w³ in its stationary
nut under the medium of the hand-wheel 102.
In consequence of the slide being guided by means of the rods ³h in the
stationary guides or sockets h h h of the frame and by virtue of the arrange-
ment of the leverses and v's a permanently parallel motion of the pressure-bar
with relation to the cutting edge of the knife is secured.
If therefore at the commencement of cutting an irregular-shaped or ill-grown
block it presses against the presser-bar 2 so that first the one end of the latter
touched the block, then only a partial counter-action of the spring through the
medium of one of the two levers s and s¹ respectively, will take place. On the
further advancing motion of the knife-frame the spring will be further compressed
by the said actuated lever, while the other lever will be at the same time discharged,
so that the presser-bar will easily follow throughout its whole length the yielding
motion caused at any part of the same. This second lever is then entirely or partially
discharged only until the moment, when the presser-bar is enabled to uniformly press
against the wood and a slice of uniform thickness from the whole length of the
block can be cut.
In case of a block or log of wood of conical or other irregular form is to be cut
into boards or veneers and the knife-frame is continually or periodically moved
against the block, the bar and slide 2 will first yield at that end where it first
touches the block. If this should happen, for instance, at I (Figure 2) the motion

page_text: of the bar h would be transmitted by means of the arms of the lever
v upon the
spring, which at the same time releases the lever correspondingly, and con-
sequently the opposite end II of the bar h, and the latter is caused to move under
all circumstances parallel to the cutting edge of the knife, notwithstanding the play
permitted by the spring w.
Instead of making the slide 2 together with the bar h yielding from one end to
the other, the slide may be fixed to the knife-frame but in this case I provide a
flexible presser-bar or the like, which yields in itself. For this reason I construct
the said presser-bar of a considerable number of small parts * each of which to be
attached separately to the slide 2 by means of bolts and a layer of elastic
materials, such as india-rubber is placed behind all parts h of the presser-bar
(Figure 5) so that each part may yield independently from the other under the
pressure and according to the varying resistance of the wood at different points of
the cutting edge of the knife.
This construction of the presser-bar is particularly applicable in cutting wood
of unequal constitution, as for instance knotty or branchy wood.
Instead of using a layer of elastic material, such as india-rubber to be placed
throughout behind all the parts h* of the flexible presser-bar as above mentioned,
I sometimes prefer to connect rigidly each part of the presser-bar to an
elastically yielding bolt or piston r, which is actuated by a helical spring ², or by
compressed air or other similar means. These bolts or pistons are truly fitting
to corresponding holes of a separate bar which is rigidly secured by the screw-
bolts to the fixed or movable slide 2 of the knife frame, and the coiled
springs or other elastic means are received within the annular space left in the
holes by the pins 3 extending through the bottom of the holes so that the
springs will bear against the shoulder of the pistons and the bottom 70 of
the piston holes **. As the end of each pin extending beyond the bottom 70
is provided with thread upon which is received a suitable nut the tension of
each spring may be conveniently regulated and also each part of the presser-bar
easily adjusted in such a manner, that the pressing edges of the same, just behind
the cutting edge of the knife, will form a straight line throughout (Figure 9).
This device is particularly applicable where it is desired to secure an absolutely
parallel yielding motion of each part of the presser-bar in relation to the cutting
edge of the knife. As for this reason a certain space must be left between the
parts of the presser-bar and the bar on top of each part is fastened a plate t
overlapping the said space and so protecting the same to be occupied by chips or
dirt of any kind.
In order to reduce the resistance caused by the friction between the wood and
the presser-bar the single parts of the latter may be provided at that edge which
bears against the wood with small anti-friction rollers in such a manner that only
a small part of their periphery will project beyond the presser-bar (Figure 6).
These rollers have to be arranged or the knife adjusted in such a manner, that a
plane at right angles to the cutting line or the cutting edge of the knife will
exactly meet the axes of the anti-friction rollers, so that the said rollers will receive
the pressure caused from the resistance of the wood to be cut, in order to discharge
the knife entirely from lateral pressure of the wood. These rollers may be divided
themselves in the single parts * of the presser-bar or one flexible roller may be
used simultaneously for two or more separate parts of the presser-bar without
departing from the nature of my invention.
I am aware that prior to my said invention flexible presser-bars have been used
in veneer-cutting machines and that rollers have been applied in combination with
stationary presser-bars. I therefore do not claim such combination broadly.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
First. In wood working machinery for cutting boards and veneers from a block

page_text: of wood, the combination with the knife-frame and cutting knife, of the yielding
presser-bar attached to a slide having projecting rods guided in bearings of said
frame, the opposite levers engaging with said rods, and the adjustable spring
pressure acting upon the inner ends of said levers, substantially as and for the
purpose hereinbefore described.
Second. In wood working machinery for cutting boards and veneers from a block
of wood the combination with the knife frame and the cutting-knife of a presser-
bar formed of a number of single parts independent of each other, attached to the
yielding or fixed support and of the elastic layer or device arranged between the
said support and the presser-bar, substantially as and for the purpose specified.
Third. In wood working machinery for cutting boards and veneers from a block
of wood the combination with the knife-frame carrying a cutting-knife of a yielding
presser-bar formed of a number of single parts attached independently from each
other to a yielding or stationary support and provided with a roller or rollers and
an elastical layer or device arranged between the said support and presser-bar
substantially as and for the purpose set forth.
Fourth. As an improvement in wood-working machinery for cutting boards and
veneers from a block of wood the combination with the knife-frame carrying a knife
of the presser-bar composed of a series of independent sections, the bolts secured
to said sections, the rigid bars to which said bolts are connected and the elastic or
spring pressure between said rigid bars and sections forcing the latter outwardly, as
set forth.
Fifth. As an improvement in wood-working machinery for cutting boards and
veneers from a block of wood the combination with the knife-frame carrying a
knife, of the presser-bar composed of a series of independent sections, the bolts or
pistons secured to said sections, the rigid bars, to which said bolts are connected
and the elastic or spring pressure in said bar forcing outwardly on said bolts and
sections, as set forth.
Sixth. The combination with the rigid bar having holes or openings, of the
presser-bar composed of a series of independent sections the bolts or pistons secured
to said sections and extended through said holes, and the springs located therein
and bearing outwardly on the said bolts and sections as set forth.
Seventh. The combination, with the rigid bar having holes or openings of the
presser-bar composed of a series of independent sections the bolts or pistons secured
to said sections and extended through said holes, the springs located therein and
bearing outwardly on said bolts and sections, and the plate secured to the
upper ends of said sections and projected over the forward edge of said bar z as
set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.