DEBARKING SHAFT FOR A DEBARKING MECHANISM

TIGE D'ECORCAGE POUR MECANISME D'ECORCAGE

English Abstract

The invention relates to a debarking shaft (3) for a debarking mechanism (1),
said debarking mechanism being intended for the decortication or pretreatment
of trees (2) for separately performed final barking and for the expulsion of
at least some of the removed barks from a wood flow passing through the
debarking mechanism, said debarking mechanism comprising a number of rotatable
debarking shafts (3) extending parallel to the advancing direction of the
trees (2) to be fed therethrough and provided with a number of teeth (4)
extending beyond the circumferential surface of the shaft (3) and adapted to
strip bark off the presently processed trees (2) transversely to the
lengthwise direction of the trees and at the same to convey the trees
transversely relative to said shafts (3), and said shafts (3), together with
the teeth (4) thereof, being adapted to constitute at least a part of a
support surface, upon which the presently processed trees (2) travel through
the debarking mechanism (1). The debarking shaft (3) has its teeth (4)
designed as a number of annular tooth rims (20), each of said tooth rims
comprising two or more releasably connected elements (21, 22), having the
outer periphery provided with the teeth (4) and said elements being adapted to
be fitted around a body member (25) of the debarking shaft (3) by way of press
clamping.

French Abstract

Cette invention se rapporte à une tige d'écorçage (3) pour mécanisme d'écorçage (1), lequel est conçu pour décortiquer ou prétraiter des arbres (2) en vue d'effectuer séparément un écorçage final et l'expulsion d'au moins une partie des écorces décortiquées sur un flot de bois passant dans le mécanisme d'écorçage. Ce mécanisme d'écorçage comprend un certain nombre de tiges d'écorçage rotatives (3) s'étendant parallèlement à la direction d'avance des arbres (2) devant être acheminés dans le mécanisme et pourvues d'un certain nombre de dents (4) s'étendant au-delà de la surface périphérique de la tige (3) et destinées à écorcer les arbres en cours de traitement (2) transversalement à la direction longitudinale des arbres et en même temps à acheminer les arbres transversalement par rapport auxdites tiges (3). Ces tiges (3), ainsi que leurs dents (4), sont conçues pour constituer au moins une partie d'une surface de support, sur laquelle les arbres en cours de traitement (2) sont acheminés dans le mécanisme d'écorçage (1). Les dents (4) de la tige d'écorçage (3) sont conçues sous la forme d'un certain nombre d'anneaux dentés (20), comprenant chacun au moins deux éléments reliés amovibles (21, 22) dont le pourtour extérieur est pourvu de dents (4), ces éléments étant conçus pour être disposés autour d'un élément de corps (25) de la tige d'écorçage (3) au moyen d'un serrage par pression.

Claims

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CLAIMS

1. A debarking shaft for a debarking machine, said debarking
machine comprising a number of rotatable debarking shafts extending parallel
to an
advancing direction of the logs and provided with a number of teeth extending
beyond
a circumferential surface of the shaft and adapted to strip bark off the logs
transversely to a length of the logs and at the same to convey the togs
transversely
relative to said shafts, and said shafts, together with the teeth thereof,
forming at least
a part of a support surface, upon which the logs travel through the debarking
machine, characterized in that said teeth are carried by a number of annular
tooth
rims, each of said tooth rims comprising two or more releasably connected
elements
having an outer periphery provided with the teeth and said elements being
clamped
around a body member of the debarking shaft.

2. A debarking shaft as set forth in claim 1, characterized in that the
elements of the tooth rim are provided with clamps for forcing the elements
toward
each other against the body member of the debarking shaft.

3. A debarking shaft as set forth in claim 2, characterized in that the
clamps comprises a headless screw, having one end provided with a left-handed
thread and the other end with a right-handed thread, as well as a gripping
section
between the threads for turning the headless screw.

4. A debarking shaft as set forth in claim 1, characterized in that the
debarking shaft body member comprises a circular pipe.

5. A debarking shaft as set forth in claim 1, characterized in that the
debarking shaft body member is provided, for each tooth rim, with a guide
element,
preferably a key and slot, for guiding the tooth rims to position.

6. A debarking shaft as set forth in claim 1, characterized in that the
debarking shaft body member has a polygonal cross-section.

7. A debarking shaft as set forth in claim 1, characterized in that the
teeth strip bark from the logs in both rotating directions of the debarking
shafts.

8. A debarking shaft as set forth in claim 1, characterised in that the
teeth facing in opposite rotating directions of the debarking shaft are
different from


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each other.

9. A debarking shaft as set forth in claim 1, characterized in that the
teeth facing in apposite rotating directions of the debarking shaft are
identical to each
other.

10. A debarking shaft as set forth in claim 1, characterized in that the
tooth rim has one or more sections which are toothless.

11. A debarking machine for removing bark from logs fed lengthways
therethrough, said debarking machine comprising:
a plurality of rotatable debarking shafts, each debarking shaft
comprising a shaft body;
a plurality of annular tooth rims, each of said tooth rims comprising two
or more releasably connected elements having an outer periphery configured as
debarking teeth; and
clamping means for clamping said annular tooth rims to said shaft body.

12. The debarking machine of claim 11, wherein said clamping
means comprises fastener means for drawing the elements toward each other
around
the shaft body.

13. The debarking machine of claim 12, wherein the fastener means
comprises a headless screw having a left-hand threaded shank portion and a
right-
hand threaded shank portion connected by a gripping section between the left-
hand
and right-hand threaded shank portions for turning the headless screw.

14. The debarking machine of claim 11, wherein the shaft body is
cylindrical.

15. The debarking machine of claim 11, wherein the shaft body is
provided with a guide element for each tooth rim for guiding the tooth rims
into
position.

16. The debarking machine of claim 15, wherein the guide element
comprises key projecting from the shaft body or a slot in the shaft body.

17. The debarking machine of claim 11, wherein the shaft body is
configured in its cross section as a polygon.


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18. The debarking machine at claim 11, wherein the tooth rims are
provided with teeth that are effective at stripping bark from logs regardless
of the
direction of rotation of the debarking shafts.

19. The debarking machine of claim 18, wherein the teeth effective in
one direction are different from the teeth effective in the other direction.

20. The debarking machine of claim 18, wherein the teeth effective in
one direction are identical to the teeth effective in the other direction.

21. the debarking machine of claim 11, wherein one or more tooth
rims have one or more elements which are toothless.

Description

CA 02438614 2003-08-15
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Debarking shaft for a debarking mechanism
The invention relates to a debarking shaft for a debarking mechanism, said
debarking mechanism being intended for the decortication or pretreatment of
trees for separately performed final barking and for the expulsion of at least
some of the removed barks from a wood flow passing through the debarking
mechanism, said debarking mechanism comprising a number of rotatable
debarking shafts extending parallel to the advancing direction of trees to be
fed therethrough and provided with a number of teeth extending beyond the
circumferential surface of the shaft and adapted to strip bark off the
presently processed trees transversely to the lengthwise direction of the
trees and at the same to convey the trees transversely relative to said
shafts,
and said shafts, together with the teeth thereof, being adapted to constitute
at least a part of a support surface, upon which the presently processed
trees travel through the debarking mechanism.
The above type of debarking mechanism is prior known for example from US
patents 4,685,498 and 5,394,912.
In the above type of debarking mechanism, the teeth are generally mounted
fixedly in certain positions. In one application, the individual teeth can be
replaceable, but even in that case the position of a tooth on the shaft
remains always the same.
It is an object of the invention to provide a debarking shaft for a debarking
mechanism, wherein the teeth of a toothed debarking shaft are readily
removable and replaceable, as well as reversible regarding the rotating
direction thereof.
Another object of the invention is to enable an axial and peripheral
displacement and locking or clamping of teeth to a desired position.


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2
According to the invention, these objects are accomplished by means of a
debarking shaft of the invention, which is characterized in that the debarking
shaft has its teeth designed as a number of annular tooth rims, each of said
tooth rims comprising two or more releasably connected elements, having
the outer periphery provided with the teeth and said elements being adapted
to be fitted around a body member of the debarking shaft by way of press
clamping.
The tooth rim elements are preferably provided with clamping means for
forcing the elements toward each other against the body member of a
debarking shaft. The clamping means may comprise for example a headless
screw, having one end provided with a left-handed thread and the other end
with a right-handed thread, as well as a gripping section between the
threads for turning the headless screw.
The debarking shaft is preferably constituted by a circular pipe. Thus,
adjacent tooth rims present on a common shaft can be readily locked or
clamped on the shaft at an angular position arbitrarily different from each
other in the shaft rotating direction, the teeth of adjacent tooth rims being
capable of providing the shaft e.g. with helixes. The same way, the relative
distance in axial direction between tooth rims present on a shaft can be
adjusted as desired.
The debarking shaft has its body member provided, preferably for each tooth
rim, with a guide element, preferably a key and slot, for guiding the tooth
rims to position.
The debarking shaft has its body member preferably designed in its cross-
section as a polygon, whereby the tooth rims can be readily guided and
clamped to various angular positions.

CA 02438614 2005-09-13
FROM ADE & COMPANY IIUt~StP 13 2005 13:30!ST,13:29/N0,6310677103 P 3
-2a-
According to an aspect of the invention, there is provided a debarking shaft
for a
debarking machine, said debarking machine comprising a number of ratatable
debarking shafts extending parallel to an advancing direction of the lags and
provided
with a number of teeth extending beyond a circumferential surface of the shaft
and
adapted to strip bark off the logs transversely to a length of the lags and at
the same
to convey the logs transversely relative to said shafts, and said shafts,
together with
the teeth thereof, forming at least a part of a suppart surface, upon which
the logs
travel through the debarking machine, Characterized in that said teeth are
carried by a
number of annular loath rims, each of said tooth rims comprising two or more
releasably connected elements having an outer periphery provided with the
teeth and
said elements being clamped around a body member of the debarking shaft.


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3
The teeth are preferably designed to be effective in both rotating directions
of debarking shafts. The teeth effective in opposite rotating directions can
be
different from or similar to each other. When using different types of teeth
in
opposite rotating directions, the various rotating directions shall result in
different barking capacities, e.g. for wintertime barking and summertime
barking. It is also possible to use sharp teeth for the decortication of
initially
hard-to-bark or frozen trees, while worn teeth can be used for the treatment
of easy-to-bark trees. The replacement is effected simply by dismounting a
tooth rim and by remounting the same after turning it around.
Barking capacity can also be influenced by making one or more sections of a
tooth rim toothless. Hence, some of the tooth rims on a debarking shaft can
be completely or partially toothless.
The invention will now be described in more detail with reference to the
accompanying drawings, in which:
Fig. 1 shows a debarking shaft for a debarking mechanism of the invention,
in a schematic side view.
Fig. 2 shows a section along a line II-II in fig. 1.
Fig. 3 shows a section along a line III-III in fig. 2.
Fig. 4 shows a section along a line IV-IV in fig. 3.
Fig. 5 shows a section along a line V-V in fig. 3.
A debarking mechanism 1 shown in the drawings is intended for the
decortication or pretreatment of trees 2 for separately performed final


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barking and for the expulsion of at least some of the removed barks from a
wood flow passing through the debarking mechanism.
The debarking mechanism 1 is provided with a number of rotatable
debarking shafts 3 extending parallel to the advancing direction of the trees
2 to be fed therethrough. In the illustrated example, the debarking shafts 3
have each end thereof provided with sprockets 6, whereby, at least at one
end of the debarking mechanism 1, the sprockets 6 are by way of a sprocket
chain (not shown) to each other and to the gear of an electric motor, not
shown.
The debarking shafts 3 are provided with a number of teeth 4 extending
beyond the circumferential surface of the shaft 3 and adapted to strip bark
off the presently processed trees 2 transversely to the longitudinal direction
of the trees and at same time to convey the trees transversely relative to the
debarking shafts 3.
The debarking shafts 3, together with the teeth 4 thereof, constitute a part
of a support surface for carrying the trees 2 through the debarking
mechanism 1. The illustrated example includes four debarking shafts 3 which
are assembled relative to each other to define an inclined plane. Other than
that, the support surfaces comprise solid surfaces which are designed for
providing, together with the support surface constituted by the debarking
shafts, an open-ended chute covering the debarking mechanism 1 from end
to end.
The debarking shaft 3 has its teeth 4 designed as a number of annular tooth
rims 20, as best shown in figs. 3 and 4. In the example of fig. 4, each tooth
rim 20 comprises two releasably connectable elements 21, 22, having the
outer periphery thereof provided with the teeth 4. The elements 21, 22 are


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adapted to be fitted around a body member 25 of the debarking shaft 3 by
way of press clamping.
The tooth rim 20 has its elements 21, 22 preferably provided with clamping
5 means, generally designated with reference numeral 23, for forcing the
elements 21, 22 toward each other against the body member 25 of the
debarking shaft 3.
In the example of fig. 4, the clamping means 23 comprises a headless screw,
having one end provided with a left-handed thread and the other end with a
right-handed thread, as well as a gripping section 24 between the threads
for turning the headless screw. The elements 21 and 22 are provided with
mating threads, whereby the gripping section 24 can be turned for drawing
the elements 21, 22 towards or away from each other.
The body member 25 of the debarking shaft 3 is circular in its cross-section,
being preferably constituted by a circular pipe. The body member 25 may be
provided, for each tooth rim 20, with a guide element (not shown),
preferably a key and slot, for guiding the tooth rims 20 to positions
predetermined therefor.
The debarking shaft 3 may also have its body member 25 designed in its
cross-section as a polygon, whereby the tooth rims can be readily guided
and clamped to various angular positions relative to the body member 25.
According to the example of fig. 4, the teeth 4 can be designed to work in
both rotating directions of the debarking shafts 3. The effective teeth 4 can
be different from each other in different rotating directions,as shown in the
example of fig. 4, or identical to. each other. The choice of various tooth
shapes can be used to have an impact on attainable barking capacity.
Barking can be similarly influenced by setting the teeth 4 of the adjacent


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tooth rims 20 at angular positions different from each other. One or more of
the tooth rims 20 can also be toothless (not shown).
The debarking shafts 3 have each end thereof provided with smaller-
diameter shaft stubs 8, on which are mounted bearings, along with bearing
cups 9 therefor, as well as the sprockets 6. The bearing cups 9 are adapted
to be secured with screws ii to end panels 10 present at the ends of the
debarking mechanism 1 in line with the debarking shafts 3. The end panels
have a top edge thereof provided with open-topped grooves 12 for the
10 shaft stubs 8 of the debarking shafts 3, whereby, if necessary, the
debarking
shafts 3 can be readily lifted out by overhead route.

Representative Drawing