Process and Apparatus for Unbarking Wood.
Year: 1892

page_text: Date of Application, 15th June, 1892-Accepted, 13th Aug., 1892
COMPLETE SPECIFICATION.
Process and Apparatus for Unbarking Wood.
I PETER JENSEN of 77 Chancery Lane in the County of Middlesex,
Chartered Patent Agent do hereby declare the nature of this invention (a
communication to me from abroad by Carl Bache-Wüg Manufacturer and Einar
Morterud, Mechanical Engineer both of Böhnsdalen Norway) and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement :-
The inventors have observed that wood which has been floating a long time in
water and then been dried can be easily unbarked especially if wetted again and
treated wet.
Such wood is according to the inventors experiments unbarked by being acted
upon with quickly rotating brushes. The bark will thus partly become loosened
in large patches and partly be rubbed off by the brushes. The wood itself is not
at all damaged thereby and wood intended for cellulose manufacture may thus
easily be unbarked and without the least loss of wood whereas by the usual
unbarking process as much as 10 per cent. of the wood may be lost. The logs of
wood are suitably acted upon with the brushes under water or other liquid and a
machine of the following description may for this purpose be applied.
Fig. 1 of the accompanying drawings is a cross section Fig. 2 a longitudinal
section and Fig. 3 a plan of the machine.
In a trough shaped vessel 1 three spindles are mounted parallel in bearings; on
the upper spindle 2 are fixed two 3 armed bosses 3. These arms have on one side,
as in a lathe, cone centres 4 and on the opposite side discs 6 with cone centres and
screw for fixing between them a log of wood to be unbarked. The cone centres 4
are axially adjustable by means of screw threads and hand wheels 5 and the discs 6
are on spindles which can turn and at the other end have clutch halves 8.
Fig. 3 the spindles 2 and the three armed bosses are omitted in order that the parts
below them may be clearly seen.
In
The bosses have by preference three arms. Then while one log is being worked
the one that has been unbarked may be removed and at the same time a fresh log
put in between the third pair of cone points.
The clutch half 9 on the spindle 10 serves to turn the spindle 7 when brought
into gear with the clutch half 8 and also to turn the other spindles when the three
armed boss is brought into proper position. The spindle 10 has its bearing in the
end wall of the vessel 1 and can be moved axially for clutching in and out by means
of the lever 19 Fig. 3. The spindle 10 is driven by the bevel wheels 11 and 12,
the former wheel being so fitted that its spindle can slide through it, but turns
therewith; the wheel 12 is on a spindle 14 which carries a worm wheel 13 and runs
in bearings 15 and 16 outside the vessel 1. Into the worm wheel gears a worm 17
on a spindle 18 provided with fast and loose strap pulleys.
The spindle 20 which has its bearings at 23 in one end wall of the vessel 1 and in
the bracket 24 serves to carry a cylindrical brush 22 which runs parallel thereto in
arms 21. The spindle 20 at one end reaches up to the spindle 18 but is not
connected thereto; the spindle 18 carries a tooth wheel 25 which is keyed thereto
and gears with a pinion 26 on the brush spindle. The free outer end of the
spindle 20 carries à lever 27 which can be loaded with a weight that serves to
hold the brush up against the log whilst the brush is being rotated by the gear
described.
The third spindle 30 in the vessel serves to support and to drive the brush 31
which is movable in the length direction of the log. This brush is on a small

page_text: spindle 32 that is directed vertitally or slightly slanting to the spindle 30 and has
its bearings in a bracket 33; it is driven by the berel wheels 34 and 35, the latter
being fixed on a spindle 30 which outside the vessel 1 carries a worm 36 in gear
with the fixed toothed rack-37 so that the spindle as soon as it rotates is carried
along the tooth rack.
The spindle 30 is rotated by means of the strap pulley 40 which by means of
crossed and open strap is alternately driven in one direction or the other; 38 and 39
are loose pulleys for receiving the said straps. These pulleys are not on the
spindle 30 itself, but on a sleeve thereon against which the spindle does not turn
but can slide therein. The shifting of the straps is effected automatically by the
bar 41 to which are fixed the strap guides and also 2 bars 42 and 43 which are
alternately carried along by a worm 36 on the spindle 30 when the latter comes to
the end of its path. The lever 44 and the weight 45 thereon serve to limit and
correctly effect this longitudinal sliding action.
In continuation of the axis of the spindle 30, but merely abutting against the
end of that spindle there is a spindle 46 the end of which rests in the stuffing box
sleeve 47 in the end wall of the vessel 1. On its inner end the bracket 33 is fixed
which carries the brush spindle 32 whilst the spindle 30 runs freely in the boss of
the bracket 33 and is supported thereby. The spindles 30 and 46 are however
connected by means of a set screw the end of which enters an annular groove in
the end of the spindle 30. On the outer end of the spindle 46 is fixed a lever 48
which can be shifted along it, but not turn thereon and which can be loaded with a
weight at its free end. By this arrangement the brush 31 is being pressed against
the rotated. log of wood under treatment.
49 is an outlet valve at the bottom of the vessel 1. By the combined action of
the brushes 22 and 31 the log can be perfectly unbarked or cleaned by drawing out
or putting in gear the clutch and by corresponding use of the fast and loose
pulley the brushes and the log may be simultaneously rotated or either the brushes
or the log alone be rotated.
In order that irregularly shaped logs may be properly acted upon all over, the
brush 22 may be made in ring sections which are each connected to the spindle in
a feathering manner so as to enable them to act freely or independently to a certain
extent.
The machine may also be so modified that the brush 22 is made short and obtains
a movement. lengthwise of the log similarly to the brush 31 with whose bearing
bracket the arms for carrying the brush 22 may be connected by link so that the
length movement of the two brushes is effected by means of the one length movement
appliance, for instance that of the worm 36 upon the bar 37.
Instead of using clean water in the aforesaid process the lye which has been used
in the cellulose manufacture may be advantageously employed. In some cases
when no such lye is available it appears desirable to make it artificially. A thin
soda solution will then suffice. Even waste water of any kind will do. If such
liquids before being applied to the unbarking of wood logs have been much cooled
down it is well to heat them a little. Or the liquid can be applied by pouring
upon the log or the process may be carried on dry.
it
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondents I declare that what I claim is:
First. The process for unbarking wood logs consisting in the treatment of same
with rotating brushes by preference under water or other liquid which may
advantageously be warm.
Second. For carrying out the process firstly claimed a brushing machine..con-
sisting mainly of an appliance such as 3, 2, 3 wherein the wood log is fixed so that
it can be turned and of two rotating brushes such as 22 and 31-which can be pressed
against the log and of which one 22 is rotated parallel to the log and the other 31

page_text: is rotated on an axis at right angles to, or slightly inclined to the first named orusu
and is carried along the log lengthwise there and back or both rotating brushes
may have such lengthwise motion.
Third. The construction of log unbarking apparatus shown on the drawing.
Dated this 15th day of June 1805
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.