Information
-
Patent Grant
-
6357496
-
Patent Number
6,357,496
-
Date Filed
Thursday, August 10, 200023 years ago
-
Date Issued
Tuesday, March 19, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Armstrong, Westerman & Hattori, LLP
-
CPC
-
US Classifications
Field of Search
US
- 144 2091
- 144 211
- 144 213
- 144 213 A
- 144 362
- 144 365
-
International Classifications
-
Abstract
A veneer lathe comprising a piercing roller and a guiding member for producing a veneer which is free from piercing scars. A third rotational shaft (25) is raised from the position where the piercing projections (27a) of the piercing rolls (27) are pierced into the outer peripheral wall of the log (3) to a position which enables the distance between the tip end of the piercing projections (27a) and the backing plate (5a), the concave portion (4) and the guide member (6) to become larger than the thickness of the veneer (T1), and then, the third rotational shaft (25) is moved away from the log (3) up to a position which makes the piercing projections (27a) impossible to pierce the outer peripheral wall of the log (3), after which the log (3) is rotated to perform the cutting by means of knife (5).
Description
BACKGROUND OF THE INVENTION
The present invention relates to a veneer lathe (peeling machine) for cutting (peeling) a veneer by making use of a cutting knife from a rotating log.
As disclosed in U.S. Pat. No. 4,219,060; U.S. Pat. No. 4,221,247; and Japanese Patent S59-45484, there is known a veneer lathe comprising a roller disposed substantially parallel with the linear cutting edge of the knife and provided with a large number of driving members which are arranged at intervals along the axial direction of the roller, each driving member being provided along the circumference thereof with a large number of piercing projections, and a guiding member for guiding a veneer that has been cut by the knife to run along the driving members.
The aforementioned conventional veneer lathe is constructed as shown in
FIG. 13
illustrating a partial enlarged view thereof and also in
FIG. 14
illustrating a partial cross-sectional view as it is viewed in the direction of the arrow from the dot and dash line K—K in FIG.
13
. By the way, a veneer
111
to be explained hereinafter is omitted in FIG.
14
.
Referring to
FIGS. 13 and 14
, the veneer lathe comprises a cutting knife
103
, and a roller disposed substantially parallel with the linear cutting edge of the knife
103
and provided with a large number of piercing rolls
105
each functioning as a driving member which are arranged, through the interposition of a ring-shaped spacer
106
, at intervals along the axial direction of a rotary shaft
107
to be rotationally driven by a driving source (not shown), each piercing roller
105
being provided along the circumference thereof with a large number of piercing projections
105
a
, and both knife
103
and roller being mounted on a knife carriage
101
. This roller is positioned so as to enable the piercing projections
105
a
to pierce not only the outer peripheral wall portion of a log
109
in the vicinity of the cutting edge of the knife
103
but also a portion of the veneer
111
which is located immediately after the cutting thereof during the cutting operation of the log
109
.
In the space between neighboring piercing rolls
105
, there is disposed a nose bar
113
, upper end portion of which is fixed to a portion of the knife carriage
101
and the lower end of which is designed to be press-contacted with an outer peripheral wall portion of the log
109
which is located immediately before being cut by the cutting knife
103
.
In conformity with each nose bar
113
, a stripping member
115
having a stripping face
115
a
for separating the veneer
111
from the piercing projections
105
a
of piercing rolls
105
is attached to the knife carriage
101
. Furthermore, a concaved member
101
a
and a guiding member, both of which are designed to guide the veneer
111
that has been cut by the cutting knife
103
to run along the piercing rolls
105
, are attached to the knife carriage
101
.
In this case, as explained hereinafter, the veneer
111
is completely press-contacted with the stripping face
115
a
of stripping member
115
so as to form slits
111
a
on front surface of the veneer
111
, or the surface facing the stripping face
115
a
, and furthermore, for the purpose of enhancing the effect of flattening the veneer, the distance between the tip end of the piercing projections
105
a
and the concaved member
101
a
or the guiding member
117
is usually made smaller than the thickness of the veneer
111
.
By making use of the veneer lathe having the aforementioned structure, the piercing rolls
105
is allowed to rotate and at the same time, the log
109
is allowed to rotate by means of a spindle (not shown) while controlling a synchronizing mechanism (not shown) in such a manner that the peripheral speed of the log
109
becomes always identical with the peripheral speed of the piercing rolls
105
, under which conditions, the knife carriage
1
is moved at ratio of 3.5 mm per rotation of the log
109
.
As a result, as shown in
FIG. 13
, the outer peripheral wall of the log
109
is permitted to be pierced by the piercing projections
105
a
of the piercing rolls
105
as shown in
FIG. 13
, thereby giving a rotational force to the log
109
also from the piercing rolls
105
and allowing the log
109
to be cut by the knife
103
with the peripheral surface of the log
109
being pressed by the chip
113
a
of nose bar
113
, thus obtaining the veneer
111
having a thickness of 3.5 mm for instance.
In this case, the veneer
111
is pierced by the piercing projections
105
a
and allowed to move as guided by the concaved member
101
a
and the guiding member
117
to the stripping member
115
, which enables the veneer
111
to be separated from the piercing projections
105
a
and bent to form slits
111
a
in the veneer
111
. As a result, it is possible to obviate the generation of so-called curling phenomenon or a phenomenon of causing the veneer to be rounded into a cylindrical configuration, thus making it possible to obtain a flat veneer, which makes it easy to work the veneer in the following steps.
As explained above, the provision of these concaved member
101
a
, guiding member
117
and stripping member
115
is certainly important in the aforementioned veneer lathe. However, due to the piercing by the piercing projections
105
a
of piercing rolls
105
, a large number of scars are caused to be formed on the front surface of the veneer
111
.
As in a case where a face sheet to be employed as a front sheet of plywood for example is to be produced in the aforementioned veneer lathe, it is sometimes desired to obtain a veneer
111
having a flat front surface which is free from any pierced scar due to the piercing projections
105
a
of piercing rolls
105
. According to the conventional veneer lathe however, even if the rotational axis
107
of the piercing rolls
105
is moved away from the log
109
from the state shown in
FIG. 13
, i.e. moved in the rightward direction in
FIG. 13
, thus separating the piercing projections
105
a
from the log
109
as shown in
FIG. 15
, it is impossible, due to fact that the concaved member
101
a
constituting a guide member and the guiding member
117
are located along the transferring direction of veneer, to avoid the pierced scar by the piercing rolls
105
from being formed in the front surface of the veneer
111
.
Namely, in the state shown in
FIG. 15
, the log
109
can be prevented from being pierced by the piercing projections
105
a
. However, since the distance between the tip end of the piercing projections
105
a
of the piercing rolls
105
and the concaved member
101
a
or the guiding member
117
cannot be changed substantially, the veneer
111
is caused to be pierced by the piercing projections
105
a
as it passes through the concaved member
101
a
or the guiding member
117
, thereby leaving pierced scars on the surface of the veneer
111
.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a veneer lathe which is capable of producing a veneer which is free from the aforementioned pierced scars in spite of facts that the veneer lathe is provided with a driving member such as the aforementioned piercing rolls
105
and with a guiding member such as the concaved member
101
a
or the guiding member
117
.
Namely, the veneer lathe according to the present invention comprises; a knife for cutting a log; a roller disposed substantially parallel with the linear cutting edge of the knife and provided with a large number of driving members which are arranged at intervals along the axial direction of the roller, each driving member being provided along the circumference thereof with a large number of piercing projections; a driving mechanism attached to the roller; a pressure member disposed at a location which enables the pressure member to press-contact with the outer peripheral wall of the log through a plurality of spaces formed between said driving members neighboring to each other of the roller; a guiding member for guiding a veneer which is cut by means of said knife to move along said driving members; a knife carriage for mounting thereon said knife, said roller, said driving mechanism, said pressure member and said guiding member; a spindle rotatably supporting a log; and a driving for rotating said spindle; wherein said roller is enabled to take a first position wherein said piercing projections of the driving member is enabled to pierce not only the outer peripheral wall portion of a log in the vicinity of said cutting edge of said knife but also a portion of the veneer which is cut by said cutting knife and is not yet passed through said guiding member, as well as to take a second position wherein said piercing projections of the driving member is not allowed to contact with not only the outer peripheral wall portion of the log but also said portion of the veneer or wherein the tip ends of said piercing projections are contacted only with the outer peripheral wall portion of the log in the vicinity of said cutting edge, said rollers being designed to be fixed at said first position or at said second position.
According to the veneer lathe of the present invention, the roller is kept at the first position on the occasion of ordinary cutting operation. However, when it is desired to obtain a veneer having a flat smooth surface as in the case where a face sheet to be employed as a front sheet of plywood is desired to obtain, the roller is moved from the first position to the second position. As a result, it becomes possible to avoid the veneer to be cut from being pierced by the piercing projections, thus obtaining a veneer free from any piercing scar.
Although there is not any particular limitation regarding the means for moving the roller from the first position to the second position and vice versa, and for fixing the roller at these positions, the means should preferably be constituted by a first reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife or to take a position where the piercing projections are kept away from the outer periphery of log, and by a second reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position where a distance between the tip end of the piercing projections and the guiding member located in the vicinity of the cutting edge of the knife and in the running direction of the log is smaller than the thickness of the veneer being cut, and to take a position where said distance is larger than the thickness of the veneer being cut.
As for the first reciprocating member, it may be constituted by a reciprocating member which enables the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife or to take a position where the tip ends of piercing projections are allowed to contact with the outer periphery of log in the vicinity of the cutting edge.
In this veneer lathe, the first reciprocating member may be constituted by an air cylinder. Further, the second reciprocating member may be constituted by an eccentric cam, wherein the roller is rotatably secured to a lower end portion of an arm which is enabled to be moved to take, through the rotation of this eccentric cam, a position which is close to the guiding member or a position which is away from the guiding member.
Alternatively, the first reciprocating member may be constituted by a reciprocating member which enables the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife, to take a position where the tip ends of piercing projections are allowed to contact with the outer periphery of log in the vicinity of the cutting edge, or to take a position where the piercing projections are kept away from the outer periphery of log.
In this veneer lathe, the first reciprocating member may be constituted by an air cylinder provided with an intermediate stopping mechanism.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1
is a side view schematically showing one example of a veneer lathe according to the present invention;
FIG. 2
is a partial front view of the right side of the knife carriage
1
which is viewed from the direction of arrows of the dot and dash line A—A of
FIG. 1
wherein a log
3
is omitted;
FIG. 3
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line B—B of
FIG. 2
;
FIG. 4
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line C—C of
FIG. 2
;
FIG. 5
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line D—D of
FIG. 2
;
FIG. 6
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line E—E of
FIG. 2
;
FIG. 7
is an enlarged view illustrating the cutting edge portion of the knife shown in
FIG. 3
;
FIG. 8
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line F—F of
FIG. 7
;
FIG. 9
is an enlarged side view illustrating the operation according one embodiment of the present invention;
FIG. 10
is an enlarged side view illustrating the operation according another embodiment of the present invention;
FIG. 11
is an enlarged side view illustrating the operation according another embodiment of the present invention;
FIG. 12
is a side view schematically showing a modified example of a veneer lathe according to the present invention;
FIG. 13
is an enlarged sectional view illustrating a conventional apparatus;
FIG. 14
is a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line K—K of
FIG. 11
; and
FIG. 15
is an enlarged side view illustrating a conventional apparatus.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be further explained with reference various embodiments.
FIG. 1
shows a side view schematically illustrating the knife carriage
1
and spindle
2
of a veneer lathe;
FIG. 2
shows a partial front view of the right side of the knife carriage
1
which is viewed from the direction of arrows of the dot and dash line A—A of
FIG. 1
wherein a log
3
of
FIG. 1
is omitted for the convenience of explanation;
FIG. 3
shows a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line B—B of
FIG. 2
;
FIG. 4
shows a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line C—C of
FIG. 2
;
FIG. 5
shows a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line D—D of
FIG. 2
; and
FIG. 6
shows a partial cross-sectional view as it is viewed from the direction of arrows of the dot and dash line E—E of FIG.
2
.
In the same manner as in the case of the conventional veneer lathe, a veneer lathe
1
is designed to be moved at a speed which enables to obtain a predetermined thickness of veneer that can be produced through the cutting by a knife
5
as explained hereinafter. For this purpose, a male screw P to be rotated by means of a motor (not shown) is engaged with a female screw (not shown) attached to the knife carriage
1
, thereby enabling the veneer lathe
1
to horizontally move toward a log
3
at a distance equal to the thickness of veneer per revolution of the log
3
which is supported by the spindle
2
to be rotated in the direction of the arrow by means of a motor
2
a.
This veneer lathe
1
is provided with various constituent components as explained below.
Namely, a pillow bearing
7
shown in
FIGS. 2 and 3
is fixedly attached to the upper mount
10
of a nose bar table
1
a
, and a first rotational axis
9
is rotatably sustained by the pillow bearing
7
.
As shown in
FIG. 6
, a sprocket
11
is fixed to the first rotational axis
9
by means of a key
13
and a key seat
13
a
, both of which are known in structure. In this case, the rotation of a servo-motor
14
provided with a tacho-generator (not shown) for detecting the quantity of rotation is transmitted to the sprocket
11
, thereby permitting the first rotational axis
9
to rotate up to any desired angle within the range of from 0 to 180 degrees.
Further, the first rotational axis
9
is coaxially provided at one end thereof with a small diametral portion
9
a
, on which a cylindrical second rotational axis
17
is fixed by means of a key and a key seat (both not shown) under the condition as explained below. Namely, the outer diameter of the second rotational axis
17
is smaller than that of the first rotational axis
9
by 1 mm for instance, and the second rotational axis
17
is eccentrically attached to the small diametral portion
9
a
, so that when the through-hole thereof having an inner diameter which is equal to the outer diameter of the small diametral portion
9
a
is secured to the small diametral portion
9
a
, the outer periphery of the second rotational axis
17
is contacted at only one point with the outer periphery of the first rotational axis
9
. As a result, when the first rotational axis
9
is rotated, the level of the uppermost portion of the outer periphery of the second rotational axis
17
can be altered in the elevational direction of
FIGS. 2 and 3
by 2 mm at maximum for instance.
As shown in
FIG. 14
, an upper end portion of arm
19
is sustained through a first bearing
21
to the second rotational axis
17
, so that the arm
19
is permitted to rotate in relative to the second rotational axis
17
.
On the other hand, an lower end portion of arm
19
is rotatably sustained through a second bearing
23
to the third rotational axis
25
.
A fourth rotational axis
26
having a larger outer diameter than the outer diameter of the third rotational axis
25
is formed coaxially and integral with the third rotational axis
25
, and as shown in
FIGS. 2 and 3
, a large number of disc-like piercing rolls
27
each having along the outer peripheral wall thereof a large number of piercing projections
27
a
and representing one example of a driving member are mounted at predetermined intervals along the longitudinal direction and coaxially on the fourth rotational axis
26
by means of a key and a key seat (both not shown), thus constructing one embodiment of the roller.
Since the roller is constructed in this manner, when the first rotational axis
9
is rotated by means of the servo-motor
14
so as to render the level of uppermost portion of the outer periphery of the second rotational axis
17
to take the lowest state, i.e. a state shown in
FIG. 3
, the piercing rolls
27
are kept on standby at the lowest level. On the other hand, when the first rotational axis
9
is rotated 180 degrees further from the state shown in
FIG. 3
by means of the servo-motor
14
so as to render the level of uppermost portion of the outer periphery of the second rotational axis
17
to take the highest state, the piercing rolls
27
are kept on standby at the highest level.
Between each pair of the piercing rolls
27
neighboring to each other in the axial direction of the fourth rotational axis
26
, there is interposed, as shown in
FIG. 3
, a nose bar
29
representing one example of the pressure member with the upper end portion of the nose bar
29
being fixed to the nose bar table
1
a
. By the way, as explained hereinafter, the nose bar
29
is detachably provided at the lower end thereof with a chip
29
a
which is to be press-contacted with the outer peripheral wall of the log
3
at a position immediately before the knife
3
.
As shown in
FIG. 7
illustrating an enlarged view of the cutting edge portion of the knife
5
shown in FIG.
3
and also shown in
FIG. 8
illustrating a partial cross-sectional view of the cutting edge portion as it is viewed from the direction of arrows of the dot and dash line F—F of
FIG. 7
, a stripping member
8
having a stripping face
8
a
which is disposed to intersect with an imaginary circle interconnecting the tip ends of the piercing projections
27
a
is attached at each interspace between neighboring piercing rolls
27
of the nose bar table
1
a
. By the way, the nose bar
29
is omitted in
FIG. 7
for the convenience of explanation.
As shown in
FIG. 5
, a sprocket
33
is secured to one end portion of the third rotational shaft
25
, and a chain
37
for transmitting the motive power of the motor
35
mounted on the nose bar table
1
a
to the sprocket
33
is disposed therebetween while being engaged with the sprocket
36
which is secured to the rotational axis of the motor
35
, with a driven sprocket
39
which is mounted, through each bearing member, on the small diametral portion
9
a
and the mount
10
, and with a driven sprocket
41
. The sprocket
36
of the motor
35
is ordinary rotated in the direction indicated by the arrow, thereby causing the sprocket
33
to rotate in the direction indicated by the arrow. As a result, the piercing rolls
27
are caused to rotate ordinary in the direction indicated by the arrow in FIG.
7
.
In order to enable the piercing rolls
27
to reciprocatively move in the direction to contact with or separated away from a portion of the log
3
disposed in the vicinity of the cutting edge of the knife
5
, the roller is constructed as follows.
Namely, as shown in
FIG. 4
, a coupling member
19
a
is attached to one side of the arm
19
which is opposite to the side facing the knife
5
. Further, an air cylinder
43
is rotatably mounted through the terminal end portion thereof on a portion of the nose bar table
1
a
, and a flange
43
b
having a larger diameter than that of the piston rod
43
a
is attached to the distal end portion of the piston rod
43
a
which is made retractable, wherein the coupling member
19
a
and the flange
43
b
are rotatably interconnected with each other by means of a pin
44
.
By the way, the air cylinder
43
is attached to the nose bar table
1
a
in such a manner that when the piston rod
43
a
is advanced fully from the main body of the air cylinder
43
, the tip ends of the piercing projections
27
a
of the piercing rolls
27
mounted on the fourth rotational shaft
26
, which are located close to the log
3
, are enabled to take a first position which coincides with an imaginary cut line which is assumed to be cut by the knife
5
, i.e. the two dots and dash line X—X which is extended perpendicularly upward from the cutting edge of the knife
5
as shown in FIG.
7
.
Additionally, a cylindrical stopper
46
into which the piston rod
43
a
is enabled to be inserted is provided, so that when the piston rod
43
a
is moved back to the main body of the air cylinder
43
, the flange
43
b
is caused to contact with the stopper
46
, whereby the positioning of the piston rod
43
a
is effected by this stopper
46
. As a result, the piercing rolls
27
are enabled to be stopped and kept on standby at the second position which is shifted 10 mm rightward from the first position as shown in FIG.
4
.
On the other hand, as shown in
FIG. 3
, the knife
5
for cutting the log
3
which is rotatably supported by the spindle
2
(the rotation of the log
3
is effected by means of the motor
2
a
shown in
FIG. 1
) is mounted on a knife holder table
1
b
(which constitutes a lower portion of the knife carriage
1
) in such a manner that as in the case of the conventional veneer lathe, the knife
5
is sustained by a
5
a
, etc. with the cutting edge thereof being directed upward.
As shown in
FIG. 7
, a concave portion
4
is formed on the surface of the knife holder table
1
b
facing the piercing rolls
27
, and a guide member
6
is inserted into and fixed to a cut-out portion
6
a
which is formed on a surface portion of the knife holder table
1
b
facing the piercing rolls
27
. Specifically, the guide member
6
is disposed in such a manner that a portion thereof is protruded upward from the cut-out portion
6
a
and is positioned to face the stripping member
8
. Namely, these concave portion
4
and guide member
6
constitute together with the backing plate
5
a
one example of guiding member.
By the way, when the piercing rolls
27
are placed at the lowest level in the elevational direction thereof and at the same time, at the first position in the horizontal direction thereof, each surface of the backing plate
5
a
, concave portion
4
and the guiding member
6
, which faces the piercing rolls
27
, is designed to constitute a portion of concentric circle of the piercing rolls
27
with a distance between said each surface and the tip ends of the piercing projections
27
a
being set to about 2 mm.
Further, as shown in
FIG. 2
, when the connecting member
1
d
attached to the nose bar table
1
a
and the connecting member
1
c
attached to the knife holding table
1
b
are connected with each other through a connecting body
1
e
, these tables
1
a
and
1
b
can be integrated, thus forming a knife carriage
1
.
By the way, although the right side portion of the roller is shown in
FIG. 2
illustrating the front view of the knife carriage
1
, the left side portion of the roller is symmetrical to the right side portion of the roller is shown in
FIG. 2
, so that components of the same kinds as shown in
FIG. 2
are disposed therein.
When, for instance, the piercing rolls
27
are placed at the highest level in the elevational direction thereof and at the same time, at the second position in the horizontal direction thereof in the structure of roller shown in
FIG. 7
, the servo-motor
14
is actuated at first so as to rotate the first rotational shaft
9
, thereby rendering the piercing rolls
27
to take and keep a state as shown in
FIG. 3
or a state where the piercing rolls
27
are positioned at the lowest level, and at the same time, in order to keep the piercing rolls
27
in a state of standby at the first position, the piston rod
43
a
of the air cylinder
43
is advanced toward the log
3
to thereby perform the initialization.
As a result, the piercing rolls
27
are kept on standby at the position shown in
FIG. 7
, and hence, the distance between the tip ends of the piercing projections
27
a
of the piercing rolls
27
and the backing plate
5
a
, concave portion
4
and the guiding member
6
, which faces the piercing rolls
27
, can be set to about 2 mm.
Under these conditions, the piercing rolls
27
are rotated in the direction indicated by the arrow by means of motor
35
, and at the same time, the knife carriage
1
is shifted toward the log
3
at a rate of 3.5 mm per revolution of the log
3
, the rotation of the log
3
being effected by means of the spindle
2
while controlling a synchronization mechanism (not shown) so as to make the peripheral speed of the log
3
coincide all the time with the peripheral speed of the piercing rolls
27
.
As a result, in the same manner as in the case of the conventional apparatus of
FIG. 13
, the outer peripheral wall of the log
3
as indicated by a two dots and dash line is permitted to be pierced by the piercing projections
27
a
of the piercing rolls
27
as shown in
FIG. 7
, thereby giving a rotational force to the log
3
also from the piercing rolls
105
and allowing the log
3
to be cut by the knife
5
with the peripheral surface of the log
3
being pressed by the chip
29
a
of nose bar
29
, thus obtaining the veneer T having a thickness of 3.5 mm for instance.
Since the distance between the tip ends of the piercing projections
27
a
of the piercing rolls
27
and the surfaces of backing plate
5
a
, concave portion
4
and guiding member
6
is set as mentioned above, the veneer T is kept pierced by the piercing projections
27
a
due to its own weight, etc. and allowed to pass through the portions of backing plate
5
a
, concave portion
4
and guiding member
6
until the veneer T is contacted with the stripping member
8
, at which point the veneer T is removed from the piercing projections
27
a
and transferred to the next step.
The veneer T thus obtained is accompanied with a large number of pierced scars due to the piercing by the piercing projections
27
a
of the piercing rolls
27
.
Next, the production of a veneer which is desirably free from any external scars such as pierced scars as in the case of the veneer to be employed as a front sheet for constituting an outermost layer of laminate body such as plywood will be explained.
In this case, in relative to the positions of the members shown in
FIG. 7
, the motor
14
is rotated at first, i.e. before starting the cutting operation, thereby causing the first rotational shaft
9
to turn 180 degrees. As a result, the position of the second rotational shaft
17
relative to the first rotational shaft
9
is changed from the state shown in
FIG. 3
to the state shown in FIG.
9
. Namely, the arm
19
supported by the second rotational shaft
17
is caused to be raised as a whole by a height of 2 mm and at the same time, the piercing rolls
27
fixed to the fourth rotational shaft
26
is also caused to be raised by a height of 2 mm, thus keeping them in a state of standby at the highest position thereof.
Then, the piston rod
43
a
of the air cylinder
43
is moved backward so as to enable the coupling member
43
b
to press-contact with the stopper
46
, thereby shifting the piercing rolls
27
from the first position to the second position where the piercing rolls
27
are kept on standby.
As a result, the relationship between the piercing rolls
27
and other members would become as shown in
FIG. 10
showing an enlarged view of FIG.
7
. Namely, the piercing projections
27
a
are kept away from the log
3
and the distance between the tip ends of the piercing projections
27
a
of the piercing rolls
27
and the surfaces of concave portion
4
and guiding member
6
becomes about 2 mm.
By the way, the nose bar
29
and the chip
29
a
are shown in FIG.
10
.
Under this condition, in the same manner as described above, the piercing rolls
27
are rotated in the direction indicated by the arrow, and at the same time, the knife carriage
1
is shifted toward the log
3
at a rate of 1 mm per revolution of the log
3
, the rotation of the log
3
being effected by means of the spindle
2
while controlling the spindle
2
so as to make the peripheral speed of the log
3
coincide all the time with the peripheral speed of the piercing rolls
27
.
As a result, as shown in
FIG. 10
, the outer peripheral wall of the log
3
is prevented from being pierced by the piercing projections
27
a
of the piercing rolls
27
, thereby receiving the rotational force from only the spindle
2
and allowing the log
3
to be cut by the knife
5
with the peripheral surface of the log
3
being pressed by the chip
29
a
of nose bar
29
, thus obtaining the veneer T
1
having a thickness of 1 mm for instance.
The veneer T
1
is then allowed to pass through spaces between the tip ends of the piercing projections
27
a
of the piercing rolls
27
and the surfaces of concave portion
4
and guiding member
6
, and after being contacted with the stripping member
8
, the veneer T
1
is transferred to the next step. Since the distance between the tip ends of the piercing projections
27
a
of the piercing rolls
27
and the surfaces of backing plate
5
a
, concave portion
4
and guiding member
6
is set to about 2 mm during the transfer of this veneer T
1
, the veneer T
1
is prevented from being pierced by the piercing projections
27
a
during the passage thereof through these spaces, thus making it possible to obtain the veneer T
1
free from any pierced scars.
In the case of producing the veneer T
1
which is free from any pierced scars, the veneer T
1
can be produced without necessitating the rotation of the piercing rolls
27
. However, the rotation of the piercing rolls
27
during the production of the veneer T
1
would be advantageous due to the following effects.
Generally, the generation of so-called curling phenomenon or a phenomenon of causing the veneer to be rounded into a cylindrical configuration tends to occur in the production of a veneer through the cutting of a log. However, even if this curling phenomenon to round up the lower end portion located downstream side in the transferring direction of the veneer T
1
tends to be generated during the transfer thereof until it is contacted with the stripping member
8
, the lower end portion of the veneer T
1
is permitted to be contacted with the tip ends of the piercing projections
27
a
of the piercing rolls
27
which are being rotated, whereby the lower end portion of the veneer T
1
is enabled to be guided toward the stripping member
8
. As a result, the veneer T
1
is prevented from being clogged at an interface between the piercing rolls
27
and the concave portion
4
or guiding member
6
.
Moreover, once the interface between the log
3
and the nose bar
29
is clogged with wood chips (waste), a wedging effect may be generated at the interface, so that a large pushing force is imposed on the log
3
, thus giving rise to the generation of a continuous groove-like flaw on the surface of the veneer thus obtained. Even in this case, as long as the piercing rolls
27
is kept rotated, the wood chips existing at the interface can be pierced by the piercing projections
27
a
of the piercing rolls
27
and allowed to pass through a space between the chip
29
a
and the log
3
due to the rotational force of the piercing rolls
27
and to contact with the stripping member
8
. As a result, the wood chips can be removed from the piercing projections
27
a
. Furthermore, even if a recessed portion is partially generated on the surface of veneer due to the wood chips during the transfer of the veneer, the recessed portion would not become a continuous flaw.
The production of a veneer which is desirably free from any external scars such as pierced scars as in the case of the veneer to be employed as a front sheet for constituting an outermost layer of laminate body such as plywood may be performed in the following manner.
In this case also, in relative to the positions of the members shown in
FIG. 7
, the motor
14
is rotated at first, i.e. before starting the cutting operation, thereby causing the first rotational shaft
9
to turn 180 degrees so as to keep the piercing rolls
27
in a state of standby at the highest position thereof. Additionally, the position where the piercing rolls
27
is shifted away from the log and kept on standby through the actuation of the air cylinder
43
is selected to be such as described below.
Namely, the piercing rolls
27
is kept in a state of standby at the position where the distance between the tip end of the piercing projections
27
a
of piercing rolls
27
which are disposed close to the log
3
and the aforementioned imaginary line X—X would become identical with the thickness of the veneer being cut, e.g. about 1 mm as shown in
FIG. 11
at the moment when the flange
43
b
is contacted with the stopper
46
as the piston rod
43
a
is moved backward through the actuation of the air cylinder
43
from the position of the piercing rolls
27
shown in FIG.
7
.
For this purpose, the length of the stopper
46
installed as shown in
FIG. 4
is extended along the moving direction of the piston rod
43
a
. For example, the interval between the flange
43
b
and the stopper
46
in
FIG. 4
is set to about 1 mm.
As described above, the piercing rolls
27
are kept in a state of standby at the uppermost position thereof through the rotation of the motor
14
and then, the distance between the tip end of the piercing projections
27
a
and the imaginary line X—X is set to about 1 mm, after which the piercing rolls
27
are rotated in the direction indicated by the arrow as shown in
FIG. 11
, and at the same time, the knife carriage
1
is shifted toward the log
3
at a rate of 1 mm per revolution of the log
3
, the rotation of the log
3
being effected by means of the spindle
2
while controlling the spindle
2
so as to make the peripheral speed of the log
3
coincide all the time with the peripheral speed of the piercing rolls
27
.
As a result, as shown in
FIG. 11
, the piercing projections
27
a
of the piercing rolls
27
is allowed to rotate at the same speed as that of the log
3
while the piercing projections
27
a
are contacted with the outer peripheral wall of the log
3
being rotated, whereby the force required for the cutting of the log
3
is substantially given by the spindle
2
, and the log
3
is cut by the knife
5
with the peripheral surface thereof being always pressed by the chip
29
a
of nose bar
29
, thus obtaining the veneer T
1
having a thickness of 1 mm for instance.
The surface of veneer T
1
thus obtained is substantially free from any pierced flaws, and even if a space between the log
3
and the nose bar
29
is clogged with wood chips as in the aforementioned example, the wood chips would be deeply pierced by the piercing projections
27
a
, thereby making it possible to reliably remove the wood chips after allowing the wood chips to pass through a space between the log
3
and the chip
3
a.
Where it is desired to cut the log
3
while allowing the log
3
to be pierced by the piercing rolls
27
in the aforementioned example, the outer peripheral wall of the log
3
is enabled to be press-contacted with the piercing rolls
27
through the adjustment of the force of the air cylinder
43
, so that the pressure of the piercing rolls
27
to be imposed on the log
3
can be suitably adjusted depending on the magnitude of the hardness of the log
3
.
For example, if a hard log is to be treated, the cutting resistance to be imposed on the knife
5
would be increased. In such a case, the pressure of the air cylinder
43
is increased so as to allow the log to be fully pierced by the piercing projections
27
a
of the piercing rolls
27
, thus making it possible to increase the driving force to be given to the log
3
from the piercing rolls
27
and hence to perform an excellent cutting. On the other hand, if a relatively soft log is to be treated, the cutting resistance to be imposed on the knife
5
would be small, so that the pressure of the air cylinder
43
is minimized so as to allow the log to be slightly pierced by the piercing projections
27
a
of the piercing rolls
27
in the cutting operation of the log
3
.
The aforementioned examples can be modified as follows.
1. The operation of shifting the piercing rolls
27
from the position where the piercing projections
27
a
are pierced into the surface of log
3
as shown in
FIG. 7
to the position where the piercing projections
27
a
are kept away from or contacted with the log
3
as shown in
FIG. 10
or
11
; or on the contrary, the operation of shifting the piercing rolls
27
from the position where the piercing projections
27
a
are kept away from or contacted with the log
3
to the position where the piercing projections
27
a
are pierced into the surface of log
3
may be performed without interrupting the cutting operation of the log
3
. Namely, without necessitating the interruption of the rotation of the log
3
, i.e. the interruption of the revolution of the log
3
, the magnitude of shifting the knife carriage
1
per revolution of the log
3
can be changed or the position of the piercing rolls
27
can be changed through the actuation of servo-motor
14
and air cylinder
43
.
2. The depth of the piercing projections
27
a
of the piercing rolls
27
in the surface of the log
3
as shown in
FIG. 7
, as well as the distance to keep the piercing projections
27
a
away from the log
3
as shown in
FIG. 10
can be suitably selected.
3. In addition to the position where the piston rod
43
a
is fully advanced from the main body of the cylinder
43
and to the position where the piston rod
43
a
is retracted back into the main body of the cylinder
43
, the air cylinder
43
may be enabled to stop at a desired intermediate position between the aforementioned positions through the application of a braking action to the piston rod
43
a
, thus modifying the air cylinder
43
into an air cylinder provided with an intermediate stopping mechanism, which can be employed as follows.
Namely, the piercing rolls
27
are enabled to take and keep a position where the piston rod
43
a
of the air cylinder is fully advanced thereby enabling the piercing projections
27
a
to pierce into the log
3
as shown in
FIG. 7
; a position where the piston rod
43
a
is slightly retracted through the action of brake, thereby enabling the piercing projections
27
a
to contact with the log
3
as shown in
FIG. 11
; or a position where the piston rod
43
a
is retracted through the release of brake, thereby enabling the flange
43
b
to be contacted with the cylindrical stopper
46
so as to keep the piercing projections
27
a
away from the log
3
as shown in FIG.
10
.
4. As for the first reciprocating member for enabling the piercing projections
27
a
of piercing rolls
27
to take a position permitting them to pierce the outer periphery of log
3
or to take a position where the piercing projections are contacted with or kept away from the outer periphery of log
3
, and as for the second reciprocating member for enabling the piercing rolls
27
to move so as to change the distance between the tip end of the piercing projections
27
a
and the guiding member such as the concave portion or the guiding portion, these reciprocating members may be formed by making use of a cam.
5. In the aforementioned examples, the guiding member for guiding a veneer that has been cut by means of a knife so as to move it along the driving members is constituted as one example by three components comprising the backing plate
5
a
, the concave portion
4
and the guiding member
6
. However, the guiding member may be constituted by a single component or a suitable number of components.
6. The cutting operation of the log
3
while allowing the outer peripheral wall of log
3
to be pierced by the piercing projections of the piercing rolls
27
as shown in
FIG. 7
may be performed in the following manner.
Namely, as shown in
FIG. 12
, a pair of driven rollers
31
and
33
disposed parallel and respectively having a rotational center which is located (spaced apart from each other by a predetermined distance) along the vertical direction orthogonally intersecting a horizontal imaginary line passing through the rotational center of the spindle
2
are disposed on the side of the log
3
which is opposite to where the knife carriage
1
is positioned. More specifically, these driven rollers
31
and
33
are contacted with the outer peripheral wall of the log and designed to be horizontally moved toward the spindle
2
at the same shifting rate as that of the knife carriage
1
during the cutting operation of the log
3
. In this construction, even if the spindle
2
is moved away from the log
3
after these rollers
31
and
33
are contacted with the outer peripheral wall of the log, the log
3
can be kept sustained by these rollers
31
and
33
, and at the same time, the driving power required for the cutting can be supplied from only the piercing rolls
27
, so that the log
3
can be cut even after the diameter of the log
3
has become smaller than that of the spindle
2
.
In this case, with a view to supplement the driving force required for the cutting of the log
3
, at least one of these rollers
31
and
33
may be constituted by a driving roller.
7. The stripping member
8
may be also provided with a shifting member for allowing the stripping member
8
to reciprocatively move in the direction orthogonally intersecting the running direction of the log
3
in the vicinity of the cutting edge of the knife
5
.
According to the veneer lathe of the present invention which is provided, on the knife carriage, with driving members each having piercing projections such as piercing rolls, and with a guiding member such as a concave portion or a guiding portion for enabling a veneer to move along the driving members, since at least a portion of the driving force required for the cutting of the log can be supplied through the piercing of the piercing projections into the surface of the log, a veneer which is free or substantially free from piercing flaws can be produced.
Claims
- 1. A veneer lathe which comprises;a knife for cutting a log; a roller disposed substantially parallel with the linear cutting edge of the knife and provided with a large number of driving members which are arranged at intervals along the axial direction of the roller, each driving member being provided along the circumference thereof with a large number of piercing projections; a driving mechanism attached to the roller; a pressure member disposed at a location which enables the pressure member to press-contact with the outer peripheral wall of the log through a plurality of spaces formed between said driving members neighboring to each other of the roller; a guiding member for guiding a veneer which is cut by means of said knife to move along said driving members; a knife carriage for mounting thereon said knife, said roller, said driving mechanism, said pressure member and said guiding member; a spindle rotatably supporting a log; and a driving for rotating said spindle; wherein said roller is enabled to take a first position wherein said piercing projections of the driving member is enabled to pierce not only the outer peripheral wall portion of a log in the vicinity of said cutting edge of said knife but also a portion of the veneer which is cut by said cutting knife and is not yet passed through said guiding member, as well as to take a second position wherein said piercing projections of the driving member is not allowed to contact with not only the outer peripheral wall portion of the log but also said portion of the veneer or wherein the tip ends of said piercing projections are contacted only with the outer peripheral wall portion of the log in the vicinity of said cutting edge, said rollers being designed to be fixed at said first position or at said second position.
- 2. The veneer lathe according to claim 1, wherein the movement of said roller from the first position to the second position and vice versa, and the fixing of said roller at these positions are effected;by a first reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife and to take a position where the piercing projections are kept away from the outer periphery of log; and by a second reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position where a distance between the tip end of the piercing projections and the guiding member located in the vicinity of the cutting edge of the knife and in the running direction of the log is smaller than the thickness of the veneer being cut, and to take a position where said distance is larger than the thickness of the veneer being cut.
- 3. The veneer lathe according to claim 1, wherein the movement of said roller from the first position to the second position and vice versa, and the fixing of said roller at these positions are effected;by a first reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife and to take a position where the tip ends of piercing projections are allowed to contact with the outer periphery of log in the vicinity of the cutting edge; and by a second reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position where a distance between the tip end of the piercing projections and the guiding member located in the vicinity of the cutting edge of the knife and in the running direction of the log is smaller than the thickness of the veneer being cut, and to take a position where said distance is larger than the thickness of the veneer being cut.
- 4. The veneer lathe according to claim 2 or 3, wherein said first reciprocating member is formed of an air cylinder.
- 5. The veneer lathe according to claim 2 or 3, wherein said second reciprocating member comprises an eccentric cam, wherein said roller is rotatably secured to a lower end portion of an arm which is enabled to be moved to take, through the rotation of this eccentric cam, a position which is close to the guiding member or a position which is away from the guiding member.
- 6. The veneer lathe according to claim 1, wherein the movement of said roller from the first position to the second position and vice versa, and the fixing of said roller at these positions are effected;by a first reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position permitting the piercing projections to pierce the outer periphery of log in the vicinity of the cutting edge of the knife, to take a position where the tip ends of piercing projections are allowed to contact with the outer periphery of log in the vicinity of the cutting edge, and to take a position where the piercing projections are kept away from the outer periphery of log; and by a second reciprocating member mounted on the knife carriage for enabling the roller to be reciprocatively moved to take a position where a distance between the tip end of the piercing projections and the guiding member located in the vicinity of the cutting edge of the knife and in the running direction of the log is smaller than the thickness of the veneer being cut, and to take a position where said distance is larger than the thickness of the veneer being cut.
- 7. The veneer lathe according to claim 6, wherein said first reciprocating member is constituted by an air cylinder provided with an intermediate stopping mechanism.
- 8. The veneer lathe according to claim 7, wherein said second reciprocating member comprises an eccentric cam, wherein said roller is rotatably secured to a lower end portion of an arm which is enabled to be moved to take, through the rotation of this eccentric cam, a position which is close to the guiding member or a position which is away from the guiding member.
Priority Claims (2)
Number |
Date |
Country |
Kind |
11-228853 |
Aug 1999 |
JP |
|
2000-159557 |
May 2000 |
JP |
|
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4219060 |
Hasegawa |
Aug 1980 |
A |
4221247 |
Katsuji |
Sep 1980 |
A |
Foreign Referenced Citations (1)
Number |
Date |
Country |
1-24602 |
May 1989 |
JP |