Note: Descriptions are shown in the official language in which they were submitted.
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Patent Application of Michael Lindsay Capp
For
A log-chipping head
Background -- Field of Invention
This invention relates to large Log Chipping heads with attached knives and
knife holders, used to process tree logs into a rectangular shape referred to
as (cants).
Background -- Description of Prior Art
Brief description
A chipping head is used to process wood in the form of chips from the sides of
a log and in the process leave a flat smooth finish, this is accomplished by
attaching several large knife holders, which use a sharp knife. To a large hub
driven by a power source.
The chipping heads (usually 2 a left and a right) are generally set up on
slides
or shafts this enable them to be positioned in or out to accommodate different
diameters of logs. As the log moves towards these heads in a horizontal
position The conical chipper heads move to a predetermined position
calculated by scanners, which have calculated the optimum position of the
heads for the best board finish and chip recovery. Heretofore many chipper
heads have been devised for holding the arrangement of the long knifes and
short knifes.
The long knife is situated on a conical plane sweeping in a forward angle,
This long knife process's most of the log surface face into a marketable chip,
the small knife which is situated directly below but with the knife edge
positioned on a vertical plane is used cut off a chip and to provide a decent
finish,
The surface of this cant face account for one of the board faces after the
cant
has finished all primary-manufacturing processes.
In the conical head chippers as of present U.S. Pat. No 5,623,977 U.S. Pat.
No. 5,271,442, The short knife is installed in a vertical fashion with the
edge of
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The blade in a position facing forward then the long knife Which cuts in a
conical plane is mounted and slid down the holder to abut onto the top to the
Short knife. With both leading edges contacting each other As a result of this
configuration the surfaces finish has suffered because of the next to
impossible task of getting the two Knife-edges to come together in a precise
manner,
Even if the components could be made extremely precise and the
maintenance perfect, as the chipper head is processing logs small wood fiber
get in-between the two knives and starts to push against each other. This
results in the long knife creeping up the holder exposing the edge of the long
knife, which proceeds to scour the cant surface.
The object of the invention is to provide a pair of knife holding structures,
which hold a double-edged knife with profiled cutting edges on all Four
Corners. These improved structures stand independent from each other and
are there fore easily adjusted.
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Objects and Advantages
Accordingly, several objects and advantages of my invention are to provide a
superior knife holder that can be used in chipping a surface finish on cants.
(Tree logs which are squared up on two or all four sides) with very little
maintenance and provide a high quality of finish with consistent results.
This is accomplished by a new design, which uses a new knife profile and
locating configuration with the knife holders to accomplish this.
The idea consists of a pair of knife holders with the large knife holder in
front
of the small knife holder, with the small knife holder located in a post-
cutting
plane on the main hub This totally eliminates the torn fiber problems
associated with present chipping heads. The long knife now consists of two
opposing cutting faces with a twin V notch for locating the knife on the
holder
this ensures that the knife will be kept fixed to the holder with absolutely
no
chance of movement.
The profile of the long and short knife both now have a cutting profile on
each
corner of the knife, this cutting profile extends from the face and around to
the
back of the blade.
This feature on the knife allows the long knife to cut chips and impart a
finishing cut on to the surface of the cant with very little maintenance
needed
for a critical fit up between the short and long knife.
Still further objects and advantages will become apparent from a
consideration of the ensuing description and accompanying drawings.
Brief Description of the Drawings
Fig. 1 is a Primary long knife holder
Fig. 2 shows Secondary small knife holders
Fig. 3 shows profile of the knife used
Fig. 4 is a perspective view of the over all chipper head with all of the
knife
holders in place
Fig. 5 is a large hub with milled flats?
Fig. 6 shows a view of the log being processed.
Fig. 7 is a large round disk attached to the chipper hub
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Reference: Numerals
primary long knife holder
11 drilled and taped hub
12 long knife
13 small knife
14 knife clamp
six fasteners
16 milled recess
18 counter knife
secondary (small) knife holder
22 square base
24 knife holder
26 keyway
28 small knife clamp
knife profile
32 two cutting edges
34 milled V grooves
36 profiled cutting corners
38 main circular hub with flats
anvil
42 hub with fasteners
44 tree log
46 four fasteners
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Preferred Embodiment -- Description
Fig 1 is a primary long knife holder 10 used on conical head style wood
chippers the parts consist of a primary knife holder to hold the long knife 12
and a knife clamp 14.
With four fasteners 46, A milled recess 16 in the upper flat portion is used
to
hold the counter knife 18 and provide Adjustability.
Fig 2 shows the secondary (small) knife holder 20 used to put the final finish
on the cant this holder comprises of a square base 22 with a knife holder 24
which can be adjusted forward and back to set up a common finishing plane.
The small holder utilizes a keyway 26 or dovetailed recess to keep the holder
in a rigid position on the cutting plane, a small knife 13 clamp 28 is used to
hold the small knife in place.
Fig 3 shows a close up view of the knife 30 edge profile this consists of a
knife
with two cutting edges 32 and milled V grooves 34 on the under side to mate
with the counter knife. The knives are ground with profiled cutting corners 36
in the form of a radius.
This extends from the front of the knife and curves around meeting with the
back of the blade, this profile Is unique to the design in that it ramps the
knife
into the wood leaving no Knife edges to scour the surface of the cant.
Fig 4 is a perspective view of the entire knife holders and knives in place
and
on their cutting plane. These components comprise of a main circular hub with
flats 38 milled on it to fasten both of the knife holders with six fasteners
15. On
the very front of the hub a anvil 40 as it is sometime called is fixed to the
hub
with fasteners 42, it is used to control the tree log 44 a$ it I$ ~gin~
~~p~~~sed
by the conical side heads.
Fig 5 is a large hub drilled and taped 11 to attach the large and small knife
holder bases and the round disk called the anvil. 40
Fig 6 the view of a log cant as its being processed from a Arial view. Only
one
side head is shown for visual clarity.
Fig 7 is a round disk used to control the log cants while they are traveling
through the chipper heads.
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Preferred Embodiment -- Operation
Please refer to the drawings, In (fig 4) the two conical side heads are
mounted
in a fashion such as they both oppose each other and are easily adjusted in
and out to accommodate different log diameters. Only one side is shown in
the view. The large hubs 38 have flats milled on them to accept the primary
long knife holders 10 they are drilled and taped 11 (fig 5) so that these
components can be changed out when in need of repairing. In (fig 4) the long
knife 12 can be referred as the primary cutting blade and the small knife 13
as
the secondary cutting blade. Both knives have the same rounded cutting
profile 36 (fig 3) on all four corners this enables the knife to be rotated
and
used in four knife changes before sharpening this will cut down on
maintenance and knife cost. These large knife holders 10 are bolted to the
hub with fasteners 15 using the counter bored holes in the bases.
The milled recesses 16 (fig1) on the top surface structure of the large
holders
are used to accept the counter knives18. These counter knives are
mounted to the large holder with three small fasteners, which mount through
the slotted holes 17 on the counter knife 18 and thread into the large knife
base 10. This allows the counter knife to be moved in and out to adjust the
cutting depth of the knife 12 this is important so as that all knives cut on
the
same plane. Mount the long knife 12 in place using the milled V notch 34 on
the counter knife 18 which corresponds with the double V recess in the knife
34b {fig 3)
This double V notch holds the knife from moving forward or backwards due to
the wedge shape of the double V shape. In (fig 1) the knife is clamped in
place with the large knife clamp 14 and four fasteners 46. As the large knife
clamp is tightened down the knife becomes very secure due to the wedging
action between the knife clamp 14 and the counter knife 18.
Referring to (fig 4) the small secondary knife holder 20 is setup behind the
large knife holder 10. The cutting face on the short knife is situated on a
vertical plane, this short knife must be designed to cut on a smaller circle
than
the long knife. This is what is called a post cutting action, Meaning that the
long knife 12 is doing most of the cutting before the small knife 13 does.
This
is regulated by the manufactured height of the holder bases.
Refer to the drawing (fig 6) for a more detailed view of this operating
principal.
As the tree log enters the chipper head the long knifes 12 starts to profile
the
round Surface of the log 44 into a flat face; this is accomplished with no
scouring on the surtace, as there are no sharp corners. This is because the
new profile which has a curved cutting profile 36, which extends around from
the surface of the knife blade and meets the knife base, this ramps the knife
into the wood exposing no Sharp knife edges to the wood. As the log
proceeds further through the chipper head the secondary knife 13 (small
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Knife) takes of a finishing cut which is also a marketable chip. This small
knife
is also vamped into the wood with a profiled cutting corner 36
(Fig 3) In the preferred embodiment these knives are both independent of
each other this makes this chipping head design almost maintenance free
with very little work to set up. The operating principal is quite simple use a
dial
indicator to dial all installed long knives 12 to -. 025 behind rotating disk
called
anvil 40 (fig 7)(Fig 4) Install all short knives in holders and torque up to
spec
and then dial these knives to .025 over disk faces 40 using the adjustable
knife hold~~~ 2~ to accomplish this.
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Conclusions, Ramifications, and Scope
Accordingly, it can be seen that the knife with the cutting profile on each
edge
and situated as they are on the main hub makes for a low Maintenance and
user friendly design. The cutting profile of the knife enters the wood with
little
or no resistance and then as the knife passes along the face of the log
imparts a near perfect finish with no fiber tear out. This is inherent of the
curved cutting edge of the knife.
Although the description above contains much specificity, these should not be
construed as limiting the scope of the invention but as merely providing
illustrations of some of the presently preferred embodiments of this
invention.
Various other embodiments and ramifications are possible within it's scope.
For example, any number of configurations exist with the placement of the
short knives in relation of the long knife there are different angles of
attack on
the log with this knife style that can be tried the angle of the short one in
relation to the long knife.
There is just a plethora of options to try.
Thus the scope of the invention should be determined by the appended
claims and their legal equivalents, rather than by the examples given.
