Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF T~ lNV~N-llON
The present invention relates generally to an apparatus
for timber processing and more particularly, to a timber
processing workhead suitable for use in various processing
operations such as the harvesting, debarking and carriage of
trees.
BA~7~0UND OF 1~ lNV~ lON
There are currently a number of known workheads used in
forestry which are each specifically designed for one or more
particular functions involved in timber processing. For
example, there are certain workheads which are adapted for
use in the felling of trees, others for removing the bark or
for removing the limbs from felled trees, others for the
"bucking" or cutting of felled trees to length, and yet
others for the loading or carriage of processed logs into
storage regions or onto transport vehicles. It is also often
necessary to design such workheads so that they are
specifically capable of use with either hardwood or softwood,
or particular tree species.
An example of a prior art timber processing device
specifically adapted for tree felling is provided by
International Application No. PCT/SE93/00601, published on
January 12, 1995 in the name of Widegren. The device
according to Widegren includes a pair of shearing elements
together with a sawing device, so as to effect tree felling
either by sawing or shearing. Another dedicated cutting and
sawing unit is exemplified by International Application No.
PCT/SE91/00606, published on April 2, 1992 in the name of
Jansson. The unit according to Jansson includes a saw
rotatably mounted on a motor stand and knives which project
from a hub part of the saw. The knives co-act with a toothed
device on the motor stand, such as to obtain a cutting action
in addition to a sawing action.
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Devices intended for dedicated tree delimbing are
exemplified by the teachings of Australian Patent Application
No. 76409/91, published on November 14, 1991 and identifying
Wingate-Hill et al. as inventors, Australian Patent
Application No. 29636/92 published on November 26, 1992 in
the name of Milbourn, and Australian Patent No. 618,679
granted January 2, 1992 in the name of Milbourn. The
Wingate-Hill et al. device comprises a milling head having
helical cutters, the milling head being mounted on support
means such that the axis of rotation of the head is
substantially parallel to the longitudinal axis of the trunk
or log being delimbed. The first Milbourn device mentioned
above consists of a workhead housing having a circular cutter
wheel mounted thereon to rotate about a vertical axis. A
chain saw is mounted by a swivel device on the housing and
above the wheel. The second-mentioned Milbourn device
consists of a workhead mounted on an articulated boom that
can move vertically along a tree to trim the branches
thereof.
Some known timber processing workheads provide a
debarking roller assembly which engages the trunk of a felled
tree and is configured so that when the rollers are
activated, the trunk is drawn between the roller assembly.
By their compressive action against the trunk, the rollers of
the assembly cause the tree bark to loosen or separate from
the truck, thereby at least partially debarking the trunk of
the tree. This technique of timber debarking is known to
those skilled in the art as compression debarking. Because
of the nature or construction of compression debarking
rollers currently in use, the debarking capability of some
such rollers is limited. This deficiency may require
supplementing the debarking action of the rollers, for
instance by providing fixed or rotating knife edges to cut
through bark which becomes loosened from the tree trunk, but
which is not entirely removed by the rollers, or by arranging
as many as six compression debarking rollers in an apparatus
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to ensure adequate circumferential coverage of a tree trunk
drawn therebetween.
An example of a prior art debarking apparatus is found
in U.S. Patent No. 4,875,511, issued on October 24, 1989 in
the names of Wingate-Hill et al. This patent teaches the use
of a plurality of pairs of concave rollers which are mounted
in a spaced apart configuration along the linear passage of
the log through the apparatus. The rollers in each pair have
respective axes of rotation substantially parallel to each
other. One pair of rollers is grooved or otherwise roughened
or provided with welded-on bars, spikes or the like for
gripping the surface of the timber being debarked, and for
compressing the timber and bark such that the bark remains as
a tube of enlarged section around the body of the tree. A
second pair of rollers, including one or more knife blades,
is provided downstream of the first pair of rollers, the
second pair of rollers being arranged with their axes of
rotation substantially perpendicular to the first pair of
rollers. In another embodiment according to Wingate-Hill et
al., a total of six rollers arranged in three pairs is
provided, each pair having parallel axes of rotation
substantially at 60 relative to the respective axes of the
rollers in each other pair. The Wingate-Hill et al. patent
teaches that unless separate bark cutting means are provided,
each of the six rollers will have respective blades attached
to or formed on their outer surfaces. Another example of a
debarking apparatus providing compression rollers, with
circumferential knives on their outer surfaces to cut through
loosened bark, is found in U.S. Patent No. 5,111,860 issued
on May 12, 1992 and also in the names of Wingate-Hill et al.
Some prior art devices do combine several tree
processing operations, such as felling and bucking, delimbing
and bucking, or felling, delimbing and bucking. Examples of
prior art devices intended for various combined operations of
tree felling, bucking or delimbing are found in United States
~_ 217057~
Patent No. 3,981,336 issued on September 21, 1976 in the name
of Levesque, Soviet Patent No. 946,458 issued on July 30,
1982 in the names of Samodov et al., and International
Application No. PCT/SE88/00338 published on December 29,
1988, and identifying Westlund as the inventor thereof. The
Levesque device comprises a harvester head having a cutting
mechanism consisting of a pair of shear-like cutting edges
and delimbing knives mounted to a support member. The head
can be positioned vertically by a boom against a tree to be
severed and then rotated into a horizontal position for the
delimbing and further severing of the tree into bolts. The
Soviet device mentioned above consists of a jib mounted onto
a turnable, the jib providing drive rollers for translating a
tree trunk through branch stripping blades. A saw attachment
for felling trees may also be provided at the terminal end of
the jib. As for the Westlund device, it consists of a
delimbing tool having knives and a gripper which are moveable
relative to one another in the axial direction of a trunk
located in the gripper, such as to delimb the trunk as it is
translated. A pivotable saw attachment is provided for
felling and bucking of timber. None of these combined
processing devices provides integrated means for debarking
the processed timber.
An example of a prior art device which is intended for
the combined functions tree felling and bucking is found in
International Application No. PCT/SE90/00042 published on
July 26, 1990 and identifying Keller as the inventor thereof.
The harvester according to Keller provides for two pairs of
grapple arms, a feeding device in the form of a driving belt
or driving wheel, and a cutting device having a pivotable
guide bar around which a saw chain is rotatable at high
speed. The grapple arms of Keller serve to seize the tree
trunk and to delimb the trunk as it is longitudinally fed
through the harvester by the feeding device. The Keller
device does not provide for a debarking function.
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Other devices providing for various combined tree
processing functions are found in U.S. Patent Nos. 4,194,542
and 5,219,010 issued respectively on March 25, 1980 and June
15, 1993, each in the name of Eriksson, U.S. Patent No.
4,766,939 issued on August 30, 1988 in the name of Forslund,
and International Applications Nos. PCT/FI92/00027 and
PCT/FI92/00227 published respectively on September 3, 1992
and March 4, 1993, each in the name of Moisio. The Eriksson
patents disclose tree processing devices which include
cooperating grabbing arms or delimbing members, drive rollers
to feed the tree through the devices and a pivotable severing
device to cut the tree. The first-mentioned Eriksson patent
provides a device wherein the drive rollers are arranged on
the grabbing arms in order to follow the grabbing arms
towards and away from a tree. The Forslund device comprises
cooperating jaw arms, feeding units for the trunk and
delimbing tools moveable with the feeding units in a common
plane. The Moisio devices have cooperating grapple arms,
drive rollers for the trunk and articulating delimbing
cutters. None of the foregoing devices provides for the
capability to debark a tree being processed.
Yet other devices providing for various combined tree
processing functions are found in International Application
No. PCT/FI90/00147 published on December 13, 1990 in the name
of Ketonen, and Australian Patent No. 534,473 issued on
February 2, 1984 in the names of Barnett et al. The Ketonen
apparatus consists of a frame, two feed tracks disposed
opposite one another for translating a tree, front and rear
stripping blades for delimbing, and a pivotable saw for
cutting bolts to length. The Australian patent to Barnett et
al. discloses a head member for tree processing which
includes delimbing means, a clasping arrangement of arm
members and a pair of shear knives for felling of a tree. As
the head member according to Barnett et al. is caused to
gravitate down a tree to its base, the momentum of the head
member during the downward movement is such as to cause
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delimbing of the tree. The same patent also teaches that the
clasping arrangement of the arm members provides for removal
of at least some of the bark from the tree during its
delimbing.
Many workheads of these known types are typically
adapted for use with machines having a boom or beam to which
the workhead is securable. Generally, workheads which are
used in tree felling and processing operations are secured to
a boom through an uncoupled grapple or swinging link, known
in the art as a dangle connection. For instance, Canadian
Patent No. 1,083,016, issued on August 5, 1980 in the name of
Hagan, teaches a delimbing and loading head which is
articulated on the end of an arm by means of a universal
joint. The joint is connected to the head at approximately
its center of gravity so that it can swivel freely on two
axes and automatically remain in a substantially horizontal
position throughout delimbing and loading operations. Such
prior art links provide for limited control of the processing
head during a felling operation. Other prior art links,
while providing for enhanced control of the workhead, may not
achieve an appropriate range of motion for the workhead in
all required directions of movement. Yet other prior art
connections do not provide for ready maintenance access to
electrical or hydraulic control lines, or may not be
configured in a compact design.
It is therefore an object of the present invention to
provide a timber processing workhead which is intended to
alleviate or overcome one or more of the aforementioned
disadvantages or problems associated with known timber
processing workheads.
It is another object of the present invention to provide
a versatile processing workhead which may serve in a
plurality of timber processing functions, such as felling,
delimbing, debarking, bucking, carriage and loading of trees.
2170574
It is a further object in another aspect of the present
invention to provide a feed roller for use in a feed roller
assembly of a timber processing workhead, which feed roller
is also suited for compression debarking of felled timber.
It is a further object in another aspect of the present
invention to provide a rotatable and pivotable coupled wrist
connection between a processing workhead and a beam or boom
to which it is connected, which is intended to provide an
appropriate range of motion and a sufficient degree of
control for the workhead operator involved in various timber
processing activities.
It is a yet further object of the present invention to
provide the rotatable and pivotabIe coupled wrist connection
of the kind mentioned above, wherein the connection is
associated with a fluid delivery manifold that is configured
in a relatively compact design, and which is intended to
provide for a sufficient degree of access to electrical and
hydraulic control lines for maintenance purposes.
BRIEF DESCRIPTION OF THE INVENTION
According to one broad aspect of the present invention,
there is provided a workhead for timber processing, the
workhead comprising:
(a) a main body;
(b) mounting means for attachment of the main body to a
support structure;
(c) wrist means for pivotal movement of the main body
relative to the support structure about a pivot axis and for
slewing movement of the main body relative to the support
structure about a slew axis;
(d) hydraulically powered timber processing means
provided with the main body;
(e) fluid delivery means for supplying hydraulic fluid
to the powered timber processing means, the fluid delivery
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means comprising a swivel hydraulic manifold extending
externally of the main body along the slew axiæ and a fixed
hydraulic manifold attached to the main body, the swivel
manifold comprising a substantially cylindrical rotor portion
and a corresponding sleeve portion in sealed rotational
engagement therewith, the rotor portion being attached to the
fixed manifold, the sleeve portion providing a fluid inlet
port and the rotor portion providing a corresponding fluid
receiving channel disposed circumferentially along an outer
surface thereof, the fluid receiving channel being in
constant fluid communication with the fluid inlet port of the
sleeve portion throughout relative rotational movement of the
rotor portion and the sleeve portion, the fluid receiving
channel being in fluid communication with a corresponding
fluid through passage provided in the fixed manifold, the
fixed manifold providing an outlet port on an external
surface thereof in fluid communication with the fluid through
passage thereof; and
wherein the outlet port of the fixed manifold supplies
hydraulic fluid received from the inlet port of the swivel
manifold to the powered timber processing means of the main
body of the workhead.
According to another broad aspect of the present
invention, there is provided a feed roller for use in timber
processing for compressive removal of bark from a felled
tree, the feed roller comprising:
(a) a base portion providing a cylindrical outer
surface and opposed terminal ends, the base portion being
rotatable about a longitudinal axis thereof; and
(b) a plurality of engaging means for engaging the
surface of timber, the engaging means projecting generally
radially from the base portion and extending along the outer
surface thereof between the opposed terminal ends of the base
portion in a generally helical configuration, each engaging
means being spaced apart from an adjacent engaging means in a
substantially parallel relationship with respect thereto,
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each engaging means having a contacting edge to engage the
surface of timber, the contacting edge providing blunt
longitudinally extending projections thereon.
According to yet another broad aspect of the present
invention, there is provided a workhead for timber
processing, the workhead comprising:
(a) a main body;
(b) a jaw assembly for grappling timber, the jaw
assembly including first and second cooperating pairs of jaw
arms, the jaw arms each having a free end and a connected
end, the connected ends of the jaw arms each being pivotally
mounted to the main body for relative movement of the jaw
arms of each cooperating pair between an operative position,
wherein the free ends of the jaw arms thereof are brought
towards each other to grapple timber therebetween, and a
release position, wherein the free ends of the jaw arms
thereof are spaced apart from each other to surrender said
timber, a jaw arm in each cooperating pair of jaw arms being
mounted adjacent a jaw arm of the other cooperating pair
along the same side of the main body of the workhead;
(c) a timber delimbing means associated with the first
cooperating pair of jaw arms, the timber delimbing means
comprising cutting blades provided respectively on each of
the jaw arms thereof; and
(d) a feed roller assembly having: a plurality of feed
rollers driven in cooperative rotation for translating a
felled tree along a longitudinal axis thereof through the
delimbing means when the jaw arms thereof are actuated to the
operative position to encircle the felled tree about its
circumference, the cutting blades being positioned on the jaw
arms of the delimbing means to effect delimbing of the felled
tree as it is axially translated therethrough; first and
second feed rollers of the feed roller assembly each being
associated with the respective jaw arms of the second
cooperating pair of jaw arms of the jaw assembly, the first
and second feed rollers each engaging the felled tree when
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the jaw arms associated therewith are actuated to the
operative position, the feed rollers each having a respective
axis of rotation substantially parallel to respective planes
of pivotal motion corresponding to the jaw arms associated
therewith; and a third feed roller of the feed roller
assembly being rotatably mounted on the main body, for
pivotal movement relative thereto, between an operative
position wherein the third feed roller engages a tree trunk
being grappled by the jaw assembly and a retracted position
wherein the third feed roller disengages the tree trunk.
With reference to preferred embodiments of the present
invention, there is provided a workhead suitable for use with
an apparatus having a beam or boom operatively connected to a
support or carriage, the workhead comprising a main body,
mounting means operatively connected to the main body for
attaching the workhead to the beam or boom, coupling means
for permitting pivotal movement of the workhead about a pivot
axis relative to the boom, slewing means for permitting
rotation of the main body about a slew axis, the pivotal
movement about the pivot axis and the rotational movement
about the slew axis permitting at least limited universal
movement of the main body relative to the beam or boom when
the workhead is operatively connected thereto, and a jaw
assembly comprising at least two cooperating jaw arms which
are each pivotally mounted to the main body for movement
between an operative position and a release position.
When in use in the operative position, the jaw arms are
adapted to hold or engage one or more tree trunks
therebetween, and in the release position, the jaw arms are
spaced apart relative to one another to release any tree
trunks held when the jaw arms are previously in the operative
position.
According to one particular embodiment of the present
invention, the workhead is adapted to perform a series of
~_ 2170574
11
varied processing operations. According to another
particular embodiment of the invention, the workhead is
adapted for a lifting and carrying function. For example, in
the first mentioned embodiment, the processing head may be
able to perform two or more of the following operations: it
may be adapted to grip the tree during the felling operation
and be capable of lowering it to the ground; it may be
adapted to remove the bark from the felled tree; it may be
adapted to remove limbs from the felled tree; it may be
adapted to cut to a selected length the trunk of the tree;
and/or it may be adapted to load, deposit or carry the
processed logs in or to a desired position, known to some
skilled in this art as "hoe-chucking" or "shovel logging".
The main body of the workhead according to either of the
aforementioned embodiments may be in the form of a support
structure or frame to or by which the mounting means,
coupling means, slewing means and a jaw assembly all may be
operatively supported. The mounting means may be in the form
of a bracket which is operatively connected by coupling means
to the beam or boom of the support structure or carriage for
the workhead.
The coupling means for operatively connecting the
mounting bracket of the workhead to the beam or boom of the
support structure or carriage includes an actuating means
which is preferably in the form of a hydraulic actuator
mechanism. One end of the actuator mechanism is connected to
the boom and the other end is connected to a guide linkage
mechanism for interconnecting of the boom and the bracket.
The reciprocating motion of the actuator mechanism acting
through the guide linkage mechanism will cause pivotal
movement of the mounting bracket and thereby the main body of
the workhead. Preferably, two guide links are provided, one
being connected between the boom and the hydraulic actuator
and the other being connected between the actuator and the
bracket.
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Preferably, the slewing means for the workhead comprises
a slew bearing adapted to be disposed between the mounting
bracket and the main body of the workhead. Drive means
associated with the slew bearing are provided for causing
rotation of the main body about the slew axis. Such drive
means may be in the form of hydraulic motors, although it
will be appreciated that other forms of drive means could be
utilised for the slew bearing.
In the embodiment discussed above for which the workhead
is particularly adapted as a lifting and carrying mechanism,
the jaw assembly may comprise two sets of spaced apart
cooperating jaw arms, each of the arms having one end
pivotally connected to the main body so that the cooperating
arms in each set can pivot towards or away from each other
between respective operative and release positions. The jaw
assembly may further include cross-members extending between
respective adjacently disposed arms in each set.
In the embodiment referred to above for which the
workhead is adapted to perform varied functions, the jaw
assembly may comprise two sets of jaw members. One set of
jaw members consists of a pair of cooperating jaw arms
pivotally connected to the main body and having associated
therewith a plurality of feed rollers which form part of a
feed roller assembly. The feed rollers are each adapted and
are preferably together configured to rotate and draw the
tree trunk therebetween when the feed rollers are rotated. A
second set of cooperating jaw arms may be provided, the
second set being arranged in a spaced apart relationship to
the first set. The arms of the second set have delimbing
means thereon, for instance blade sections with knife edges,
so that in their operative position and when the tree is
translated through the jaws by the feed roller assembly, the
blade sections with knife edges are positioned to remove
limbs from the tree trunk. A delimbing knife may also be
provided in the main body of the workhead to provide for
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greater circumferential coverage of a trunk during its
delimbing by the second set of arms of the workhead.
The feed roller assembly may further include one or more
additional rollers located in the main body of the workhead,
which are adapted to cooperate with the feed rollers in the
jaw arms to define the feed roller assembly. There is at
least a single feed roller mounted in the body of the head.
Preferably, this feed roller is a retractable cushion roller
mounted on a swinging arm which may, for example, be
controlled by a hydraulic actuator. When the workhead is in
its processing mode, the hydraulic actuator is activated and
the cushion roller is pushed forward to engage the log.
During all other modes of operation, the hydraulic actuator
is not activated and the cushion roller remains in a
retracted position. The purpose of retracting this feed
roller is that during felling, the tree will be in contact
only with the feed rollers on the arms and with portions of
the main body of the head, such as the delimbing knife
provided thereon. This ensures maximum clamping stability
during felling as well as when handling processed logs, such
as when timber is being carried or loaded onto a transport
vehicle. Additionally, a relief valve may be provided in the
hydraulic supply line for the hydraulic actuator which
activates the swinging arm of the cushion roller. The relief
valve may be set to a preselected pressure so as to reduce
the supply of hydraulic fluid to the swinging arm actuator in
the event of excessive radial load to the roller, for
instance, as may occur during the processing of crooked
trees.
The processing head may further include a severing means
such as a saw attachment which may be pivotally mounted to
the main body. In operation, the saw attachment can be
pivoted in order to cut across the trunk of a tree or log,
for felling or bucking purposes. Other severing means may be
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14
adapted for use with the workhead according to the present
invention, as will be apparent to those skilled in this art.
A measuring device may be provided with the processing
workhead to measure the length of logs to be cut. The
measuring device may be mounted on a mechanism forming part
of the main body which allows the measuring device to be held
in a protruding position whilst in a processing mode. During
all other modes of operation, the measuring device is in a
retracted position to avoid damage. Preferably, the
measuring device is resiliently mounted on the main body to
accommodate dimensional variances and surface discontinuities
encountered along the length of processed logs. Those
skilled in this art will appreciate that other measuring
devices may be incorporated for use with the workhead
according to the present invention.
The particular design of the feed rollers for the
workhead described above forms another aspect of the present
invention. The design of the feed roller may permit it to be
used in the debarking of a wide variety of tree species.
With reference to embodiments pertaining to this aspect
of the present invention, there is provided a feed roller for
use in a feed roller assembly of a processing workhead, the
feed roller comprising a base section having a generally
cylindrical outer surface, and a plurality of engaging bars
which are secured to or formed integral with the outer
surface to project generally radially therefrom. The
engaging bars are spaced apart and generally parallel to one
another, each engaging bar extending in a generally spiral
configuration from one end of the feed roller base section to
the other.
Preferably, each of the engaging bars is of greater
height dimension towards the end portions of the base section
of the feed roller, and is arranged to taper inwardly as the
7057~
bar approaches an intermediate portion thereof. The outer
edges of each of the bars, taken along a parallel plane
running between the end portions of the base, trace a
generally concave or fluted engaging edge. Furthermore, it
is desirable that the top surface of the engaging bars, when
viewed in longitudinal cross-section, be generally concave in
shape so as to provide a generally concave envelope surface
to the feed rollers.
Preferably, the feed rollers of the processing head are
driven by a load sensing pressure compensated hydraulic
system which is fitted with a flow dividing valve to give
positive drive to all rollers under all conditions. As well,
hydraulic fluid is supplied and returned through the workhead
wrist connection via a combined swivel manifold and block
manifold, which results in a compact design.
The processing workhead according to the present
invention is capable of cutting a tree off its base, holding
the felled tree in an upright position, moving the tree while
in this position to various other desired positions, and
lowering or raising the tree in numerous desired directions.
Such manipulation of a felled tree may be made prior to,
during or after delimbing, debarking and bucking of the tree
by the processing workhead. In addition, the processing
workhead is also advantageously capable of grappling,
bunching, shovel-logging and loading a plurality of processed
logs.
BRIEF DESCRIPTION OF 1~ DRAWINGS
For purposes of illustration and understanding of the
invention, but not of limitation, reference will be made to
the following drawings in describing various aspects and
embodiments of the present invention, in which:
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16
Figure 1 is a schematic perspective view of a timber
processing workhead according to a first embodiment of the
present invention;
Figure 2 is a side elevation of the workhead according
to the present invention, being operatively connected to the
articulated boom of an associated all-terrain vehicle;
Figure 3 is a detail of the coupling mechanism by which
the workhead is coupled to the vehicle boom of Figure 2,
showing a hydraulic actuator of the boom in a fully extended
stroke position;
Figure 4 is a similar view to Figure 3, with the
hydraulic actuator of the coupling mechanism being shown in a
fully retracted stroke position;
Figure 5 is an end elevation of the timber processing
workhead according to the embodiment of the present invention
shown in Figure 1;
Figure 6 is an underside plan view of the workhead of
Figure 1;
Figure 7 is a side elevation of the workhead of Figure
1;
Figure 8 is a side elevation of a feed roller according
to another aspect of the present invention;
Figure 9 is an end elevation of the roller shown in
Figure 8;
Figure 10 is a side elevation of a portion of an
engaging bar which forms part of the feed roller according to
the present invention;
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17
Figure 11 is an end elevation of the working bar portion
of Figure 10, viewed along direction "A" of Figure 10;
Figure 12 is a partial cross-sectional view of the
fluted outside edge of the working bar of Figure 10;
Figure 13 is a schematic side elevation of two engaging
bar portions of Figure 11, showing their helical placement
along the outer surface of a feed roller according to the
present invention;
Figure 14 is a schematic cut-away section of a feed
roller and housing according to another aspect of the present
invention;
Figure 15 is a partial cross-sectional end view of a
retractable cushion roller assembly located in the main body
of the workhead according to Figure 1;
Figure 16 is a partial cross-sectional side view of the
cushion roller assembly of Figure 15;
Figure 17 is a partial cross-sectional view of the main
body of the workhead of Figure 1, showing a retractable
length measuring device for use with the present invention;
Figure 18 is a schematic end elevation of the workhead
according to a second embodiment of the present invention;
Figure 19 is a schematic underside plan view of the
workhead shown in Figure 18;
Figure 20 is a schematic side elevation of the workhead
of Figure 18;
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18
Figure 21 is a schematic layout of a hydraulic circuit
adapted for operating and controlling the various powered
devices of the workhead according to Figure 1;
Figure 22 is an exploded cross-sectional view of a
slewing means according to yet another aspect of the present
invention, the slewing means being suited for use with the
workhead of the present invention;
Figure 23 is a top plan view of the slewing means of
Figure 22; and
Figure 24 is a detailed partial cross-sectional view of
drive means for the slewing means of Figures 22 and 23;
Figure 25 is a schematic cross-sectional view of a
swivel manifold and underlying block manifold provided in the
main body of the workhead of the present invention; and
Figure 26 is a schematic perspective view of the
manifolds of Figure 25, showing the relative slewing movement
thereof.
DETATT~n DESCRIPTION OF PREFERRED EMBODIMENTS
With particular reference to Figure 1 and Figures 5 to
7, the timber processing workhead 10 according to a first
embodiment of the present invention includes a main body 11
and a wrist connection 5 which permits at least limited
universal movement of the main body of the workhead relative
to a boom 71 or other support member thereof. This
particular embodiment of the invention is intended to be
suitable for carrying out a variety of timber processing
operations, including controlled felling, delimbing,
debarking, bucking, carriage, and transporting from one site
to another. The main body 11 of the workhead 10 is
preferably in the form of a support structure or frame to or
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19
by which the wrist connection 5, a jaw assembly 30 consisting
of two pairs of cooperating jaw arms 21 and 31, and timber
feed means in the form of driven feed rollers 36 to 39 are
operatively supported. Details of the specific features of
workheads according to various embodiments of the present
invention are explained more clearly herebelow with reference
to Figures 5 to 7 and Figures 18 to 20.
Referring now to Figures 2 to 4, the timber processing
workhead 10 according to the present invention is shown
connected to an articulated boomset 71 of an associated all-
terrain vehicle 70 of the kind well known to those skilled in
this art. As shown in Figure 2, the boomset 71 is pivotally
supported by the vehicle 70, the boomset having an inner
section 72 and an outer section 73, the inner and outer
sections being capable of pivotal movement relative to one
another about a pivot connection as at 76. The vehicle
further includes an operator cabin 74, an endless track drive
system 75 and a slewing ring 77, also well known to those
skilled in this art.
The wrist connection 5 of the workhead comprises a
mounting bracket 12 to which is connected a coupling means 13
for pivotal motion of the workhead, as explained below. The
workhead is pivotally connected, as at 12a, by means of the
mounting bracket 12 at the terminal end of outer section 73
of boomset 71. Coupling means 13 for the workhead comprises
an actuator means, which is preferably a hydraulic actuator
mechanism 14 well known to those skilled in this art. The
actuator 14 is pivotally mounted at its cylinder end to outer
section 73 of boomset 71, as at 14c. The coupling means
further includes a pair of guide links 15 and 16, each of
which have an end thereof pivotally connected, as at 14b, to
the terminal end of ram 14a of the actuator 14. The end of
guide link 15 opposite the actuator ram 14a is pivotally
connected to the terminal end of outer section 73 of boom 71
adjacent the mounting bracket 12, as at 73a. The end of
~, 217057g
guide link 16 oppoæite the actuator ram 14a i8 pivotally
connected to the mounting bracket 12, as at 12b.
The coupling means 13 operatively connect the workhead
to the boom 71 so that it can pivot about an axis extending
through pivot connection 12a, denoted as AA' in Figure 5.
The configuration of the coupling means 13 with the hydraulic
actuator 14 placed beneath the outer section 73 of boom 71,
rather than above, advantageously results in the actuator
being in a state of compression during many timber handling
manoeuvres in which gravity will contribute to additional
dynamic loading of the actuator mechanism, such as in timber
handling operations.
The wrist connection 5 of workhead 10 also includes a
slewing means, preferably in the form of a slew bearing 80
which is disposed between the main body 11 and the mounting
bracket 12. Drive means associated with the slew bearing,
preferably in the form of twin reversible hydraulic motors
108, cause rotation of main body 11 about a slew axis,
denoted as BB' in Figure 4. Together, the operation of the
coupling means 13 and slew bearing 80 provide for an
appropriate degree of universal movement of the main body
relative to boom 71, as previously mentioned. Details
concerning the features and operation of slew bearing 80 are
provided herebelow.
Turning more specifically to Figures 5 to 7, the jaw
assembly 30 of the workhead 10 comprises two sets of jaw
members or arms 21 and 31. As will be best noted in Figures
6 and 7, the jaw arms of each set are slightly off-set with
respect to one another. The first set of jaw arms 31
comprises two cooperating arms 32, 33 which again are arcuate
in shape and are mounted for pivotal movement relative to the
main body 11 of the workhead. Each arm 32, 33 has a feed
roller 36, 37 attached thereto, these rollers forming part of
a feed roller assembly. The feed roller assembly further
~ 2170574
includes a pair of rollers 38 and 39 which are disposed in
the main body of the workhead. All of the feed rollers are
configured so that when activated, they will translate and
cause rotation of the tree trunk as it passes between the
rollers. The feed rollers are described in greater detail
herebelow, and effect compression debarking of a tree truck
processed by the workhead 10.
The second set of jaw arms 21, which are disposed
upstream with respect to the direction of travel of a tree
trunk through the jaw assembly during delimbing, comprises
two cooperating arms 23 and 24, which are also generally
arcuate in shape and mounted for pivotal movement towards or
away from one another. Each of these arms has a blade
section with knife edges 25, 26 associated therewith, which
can trim limbs from the tree trunk as it is translated
through the jaw members 21 by the feed roller assembly. The
arms 23, 24 provide flat surfaces 19 (Figure 6) thereon which
trail the knife edges of the blade sections. However, those
skilled in this art will appreciate that the surfaces 19 may
be sloped outwardly away from the knife edges, if desired, so
as to prevent any accumulation of wood chips, branches or
other cut material produced by the delimbing action of the
arms.
Each set of jaw arms 21 and 31 may be independently
activated into a closed operative position, wherein the free
ends of the arms are brought towards each other, or into an
open release position, wherein the arm ends are brought away
from one another. Each set of jaw arms 21 and 31 is
activated by a separate actuating means, preferably in the
form of a hydraulic actuator 148 (shown schematically in
Figure 18) well known to those skilled in this art.
A knife 27 is mounted on the main body 11 of the
workhead to provide a more complete circumferential coverage
during delimbing together with the action of blade sections
~ 2170S74
25, 26. Those skilled in this art will appreciate that the
knife 27 may be provided as a fixed knife or as a retractable
and outwardly biased floating knife, as is well known. Area
20 of the main body (Figure 5), which trails the cutting edge
of knife 27, may be provided with a sloped deflecting surface
(not shown) to prevent accumulation of cut material produced
by the delimbing action of the knife. As well, a severing
means in the form of a pivotally mounted hydraulic saw 6 is
provided at one end of the main body for cutting processed
logs to length and for tree felling.
Referring next to Figures 8 to 14, the feed roller 50
for use as a roller 36 to 39 of the workhead comprises a base
section 57 having a cylindrical outer surface 51 and a
plurality of engaging means in the form of engaging vanes or
bars 52 attached to or formed integral with the outer surface
of the base section to project generally radially
therearound. The engaging bars are adapted to extend from
one end surface 58 of the roller to the other in a generally
spiral or helical configuration, such that each engaging bar
extends 180 around the circumference of outer surface 51, as
best shown in Figure 13. Each engaging bar 52 is preferably
disposed on the outer surface 51 to form a helix angle of
- approximately 40 with respect to the longitudinal axis of
the roller 50. Eight such engaging bars are preferably
provided in an evenly spaced circumferential arrangement on
each roller 50.
The engaging bars 52 may be formed from two bar portions
52a, placed end-to-end on the surface 51 of roller 50. Each
bar portion 52a is generally arcuate in shape, and may be
formed from a plate section provided with two thin slots 58,
59 through its cross-section. The slots are located adjacent
the base edge 60 of the bar portion which is intended to
attach to the outer surface 51 of roller 50. The slots 58,
59 may be formed in a plate section for bar portion 52a by
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means such as flame cutting, or other means known to those
skilled in this art.
The provision of slots 58, 59 results in the bar portion
52a being divided into three sections, namely an inner
section 61a, an intermediate section 61b and an outer section
61c, each being angularly disposed with respect to the other.
The outer section 61c is located adjacent an end face 58 of
the roller 50, when the bar portion 52a is attached to its
outer surface 51. Intermediate section 61b is located
between the thin slots 58, 59. The inner section 61a of the
bar portion 52a is located between the end faces 58 of a
roller 50 when bar portion 52a is attached to outer surface
51 thereof. As best shown in Figure 11, inner section 61a
extends from the bar portion at an angle a of approximately
15 with respect to intermediate section 61b. Likewise,
outer section 61c of bar portion 52a extends angularly from
the bar portion at an angle a' of approximately 15 with
respect to the height dimension of intermediate section 61b
of the bar. The angular relationship between each of the
sections 61a, 61b and 61c of bar portion 52a may be obtained
by bending of the sections once slots 58, 59 have been formed
in the plate section for bar portion 52a. Other means of
constructing or forming the bar portions will be apparent to
those skilled in this art.
As best shown in Figure 10, bar portion 52a has a
greater height ~1mPn~ion towards the end portion 61a, and is
shaped to taper longitudinally to a lesser height dimension
towards inner section 61a. When two bar portions 52a are
placed end-to-end on the surface 51 of roller 50, this height
tapering results in a generally concave envelope surface for
the feed rollers 50 when viewed in longitudinal cross-
section. The base edge 60 of bar portion 52a is fixedly
attached to the outer surface 51 of roller 50 preferably by
welded attachment. Other means for constructing the roller
~ 2170574
24
50 and its engaging bars 52 will be apparent to those skilled
in this art.
The outer or contacting edge 54 of the bar portion 52a
is intended to engage a tree trunk and cause rotation thereof
as it passes through the feed roller assembly of workhead 10.
As best seen in Figure 12, outer edge 54, when viewed along a
plane parallel to the end portions 58 of base 57 of the
roller 50, traces a fluted or concave engaging edge 62 to
form projecting and spaced apart lands 62a. The shape of the
concave engaging edge 62 and the provision of flat engaging
surfaces at the outer edge 54 of bar portion 52a produces an
engaging bar 52 for the feed roller which is intended to
achieve only partial penetration of the bark of a felled tree
while avoiding appreciable penetration of the engaging bar
into the wood fibre portion thereof. In this manner, radial
shearing of the bark is lessened and the compressive action
of the engaging bar 52 required for compression debarking is
enhanced. As well, damage to the wood fibre of a log is
thereby averted or m;n;m; zed. Thus, the outer edge 54 of an
engaging bar 52 presents blunt longitudinally extending
projections thereon, such as the lands 62a which constitute
means for applying compressive force to the bark of the
felled tree without substantially effecting the radial
shearing thereof. Preferably, the blunt projections are
disposed along substantially the entire length of each
engaging bar 52. Other blunt profiles of the outer edge of
the engaging bars for achieving the foregoing purpose will be
apparent to those skilled in this art.
With reference to Figure 14, each feed roller 50 is
rotatably mounted in a roller housing 63. Base section 57 of
the roller 50 is provided as a hollow cylinder containing an
internal drive hub 65 and end bearings 66 to enable
rotational movement of roller 50 with respect to end axles
67, 68 which are fixedly attached to housing 63. Seal plates
64 are provided at each end of base section 57 of the roller
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to contain a bearing and hub lubricant and to prevent its
contamination. The seal plates provide peripheral seats 64a
for receiving a sealing means therein (not shown) in contact
with the end axles 67, 68. The drive means for the roller 50
preferably consists of a reversible hydraulic motor 69, such
as the OMTS 400 low-speed high-torque orbital motor supplied
by Danfoss A/S of Denmark. Hydraulic motor 69 provides a
splined drive shaft 169 for engagement with a corresponding
splined surface of the drive hub 65.
The feed roller, housing and motor assembly described
above results in a relatively compact arrangement, due to the
hollow nature of the feed roller base section, which serves
as a lubricant containment means. In this manner, the motor
69 need not be provided with an additional casing extension
for lubrication of its drive æhaft 169, as the feed roller
base section itself houses the necessary lubricant therefor.
As such, the roller, housing and motor assembly is rendered
more compact, along the direction of the rotational axis of
the feed roller, than would be the case if the motor were
required to have a dedicated casing extension surrounding its
drive shaft.
With reference to Figures 15 and 16, one of the feed
rollers of the workhead 10 may be provided as a retractable
cushion roller 39 in the main body 11 of the workhead. The
cushion roller is mounted on a housing or swinging arm 156
which is pivotally connected to the main body 11 as at 157.
Swinging arm 156 is biased to a retracted position by way of
one or more coil springs 158 or other like means. One end of
each coil spring 158 is attached to the free end 160 of the
swinging arm 156, whereas the other end of each spring is
attached to the main body 11 as at 162. The movement of
swinging arm 156 between an operative position, in which the
cushion roller 39 engages a log, and a retracted position in
which the log is not engaged, may be achieved by means of a
hydraulic actuator 164 or the like. When the workhead 10 is
2170~74
26
in a processing mode, such as during delimbing and debarking
operations, the hydraulic actuator 64 is activated and the
cushion roller 39 is pushed forward to engage a log being
processed. In all other modes of operation, such as during
felling and grappling, hydraulic actuator 164 is not
activated and the cushion roller remains in a retracted
position due to the biasing effect of coil spring 162.
The mechanism of the retractable cushion roller
discussed above ensures maximum clamping stability of a tree
during felling, handling and carriage, since retraction of
swinging arm 156 will cause a log held by the jaw arms of the
workhead 10 to be clamped against portions of the main body
of the head, such as the fixed delimbing knife 27. Thus,
when cushion roller 39 is retracted, the reaction to the
forces produced on a tree stem by the closed jaw assembly 30
of the workhead is through the tree and onto the frame of the
head, instead of onto the cushion roller 39. This improves
the grappling stability of the workhead, especially when a
tree is in a vertical position such as immediately following
felling.
Turning now to Figure 17, the details of a measuring
device 2 which may be mounted in the main body 11 of the
workhead for measuring the length of logs to be cut during
bucking operations is next discussed. The measuring device 2
consists of a toothed wheel 3 mounted onto the rotatable
shaft 4 of a measuring transducer 7 well known to those
skilled in this art. The transducer 7 is mounted onto a
resilient biasing means, such as a leaf spring 8 fixedly
mounted to an inside surface of main body 11 of the workhead.
This resilient mounting mechanism is intended to cause the
wheel 3 to maintain contact while accommodating dimensional
variances and surface discontinuities encountered along the
length of a processed log. A hydraulic actuator 9 may be
provided with the measuring device 2, and the actuating ram
17 thereof may be extended as shown in Figure 20 against leaf
~ 2170574
spring 8 so as to cause the wheel 3 of the measuring device 2
to extend through corresponding slot 1 provided in main body
11. This enables the measuring device 2 to be retracted when
not in use, and a coil spring 18 or the like may be used to
bias the measuring device to its retracted position. Other
measuring devices may be incorporated for use with the
workhead according to the present invention, for instance,
devices which provide information as to the diameter or
circumference of processed logs along their length.
Referring to Figures 18 to 20, the workhead in this
second embodiment of the present invention is particularly
suitable for lifting and carrying one or more logs from one
site to another. The workhead includes a jaw assembly 40
comprising two sets of cooperating arms, the first set
denoted 41, 42 and the second set denoted 43, 44. The arms
in each of the cooperating sets are slightly off-set from one
another, with arms 42, 44 being shorter in length than arms
41, 43 as best seen in Figure 20. Thus, the arms 42, 44 can
pivotally move within arms 41, 43. Cross-members 45 and 46
join respective adjacent jaw arms 42 and 44 and 41 and 43 of
each of the sets of armæ. The workhead according to the
embodiment illustrated in Figures 18 to 20 provides the same
wrist connection 5 as the first embodiment of the workhead
discussed above. However, the device of Figures 18 to 20
need not be provided with feed rollers 50. The arm
arrangement of this device is such that a shearing action is
produced when closing the arms, the shearing action being
provided by the relative movement and positions of the cross-
members 45 and 46. This permits the severance of unwanted
plant material such as vines which may need removing prior to
felling.
A preferred hydraulic circuit for the workhead of Figure
1 of the present invention is described with reference to
Figure 21. Those skilled in this art will appreciate that
alternative hydraulic circuit layouts may also be used in
~ %170574
28
order to operate and control the various workhead devices
mentioned above. The preferred circuit for use with the
present invention is a load sensing pressure compensating
circuit. The circuit comprises a pressure compensated
hydraulic fluid supply in the form of two main hydraulic
pumps 120, each having a maximum displacement of 250 l/min
and maximum pressure of 325 Bar. The pumps 120 are connected
through a bank of primary hydraulic valves 122 and secondary
hydraulic valves 124 to provide preselected rates of maximum
fluid flow to individual hydraulic circuits associated with
each powered device of the workhead. For instance, the
hydraulic circuit 126 for powering the respective hydraulic
motors 165 to 168 associated with the feed rollers 36 to 39,
and the circuit 128 for powering the hydraulic actuator
mechanism 14 of the coupling means 13 for the workhead, may
each be supplied at a maximum rate of fluid displacement of
250 l/min. Hydraulic circuit 130, which serves to power the
cushion roller hydraulic actuator 164, the drive arms 31 and
delimbing arms 21 of the jaw assembly 30 and the saw
attachment 6, may be supplied at a maximum rate of fluid
displacement of 180 l/min. Finally, hydraulic circuit 132,
which serves to power the hydraulic motors 108 which
constitute the drive means of the slew bearing 80, may be
supplied at a maximum rate of fluid displacement of 120
l/min.
A pilot hydraulic pump 121 or the like may be used in
the preferred circuit as a charge pump to operate the primary
hydraulic valves 122 and secondary hydraulic valves 124 in a
manner well known to those skilled in this art. The pilot
pump line includes a check valve 123. A fluid return line
through hydraulic filter 134 to drain 135 is also provided
from the secondary hydraulic valves 124.
Hydraulic circuit 126 for powering the feed roller
motors 165 to 168 is provided with a four-way flow divider
136 to equalize fluid flow to the roller motors and thereby
~ 2170~74
29
maintain a synchronized rotational speed of the feed rollers,
irrespective of torque ~em~n~. The four-way divider 136
therefore prevents fluid runaway to the feed roller having
the lowest pressure demand of the feed roller assembly. This
ensures that when one or more drive rollers momentarily lose
contact with a log due to surface discontinuities or abrupt
dimensional variances as may be caused during the processing
of a crooked tree, the remaining drive rollers in contact
with the log will continue to be operational at the intended
rate of hydraulic fluid supply. The four-way divider may be
in the form of a single unit, for instance the Type MH 4 FA
supplied by Mannesmann Rexroth GmbH of Germany. Those
skilled in this art will appreciate that other means may be
employed to accomplish the equalized flow to the feed roller
motors, such as the use of pressure-compensated directional
control valves, the provision of multiple two-way flow
dividers to achieve the same four-way equalized flow, or the
use of a dedicated hydraulic circuit furnished with
individual equal displacement pumps for each feed roller
motor.
The hydraulic circuit 130 is designed to provide for two
distinct and selectable arm clamping pressures for various
ti~m~ber processing operations. For instance, in its higher-
pressure "hard clamp" mode, the drive arms 31 and delimbing
arms 21 of the jaw assembly 30 may be used to hold a tree in
an upright position during felling with the saw attachment 6,
or to grapple one or more processed logs. In its lower-
pressure "æoft clampN mode, thè arms may be used for
delimbing and debarking operations. Each drive arm set and
delimbing arm set is provided with its own circuit leg, such
that the operator can select a soft clamp for the delimbing
arms and a hard clamp for the drive arms, for instance, as at
the beginning of the delimbing process to facilitate the
required axial translation of the tree being processed.
~ 2170S7g
Each circuit leg for the jaw assembly 30 provides a
downstream pressure compensated flow control valve 138
followed by a directional flow valve 140 which is used to
selectively encounter or bypass a pressure reducing valve
142. When directional valve 140 enables flow to pressure
reducing valve 142, the particular arm pair of the circuit
leg will operate in its soft clamp mode. When the
directional flow valve 140 diverts flow from the pressure
reducing valve 142, the particular arm pair will operate in
its hard clamp mode. A further directional valve 144 is
provided downstream of the pressure reducing valve 142 to
enable return flow of hydraulic fluid in each leg of the
circuit associated with an arm pair. Further downstream of
the valves 140 and 144 is an arm actuating valve 146 to
effect the opening and closing of a particular jaw arm pair
by means of hydraulic actuator 148. A pressure relief valve
150 is also provided for each circuit leg of the jaw arms,
and a single check valve 151 is provided for both circuit
legs.
Hydraulic circuit 130 further provides a directional
flow valve 152 for extending and retracting hydraulic
actuator 164 associated with cushion roller 39. The presence
of a relief valve 150 in the circuit 130 allows for the
actuator 164 to retract upon an excessive radial load being
applied to the cushion roller, for instance, as may occur
during the processing of crooked tree.
A saw attachment actuating valve 154 completes the
hydraulic circuit 130. The valve 154 controls fluid flow to
the saw motor 155 and to a hydraulic actuator (not shown) for
causing pivotal movement of the saw attachment 6 during
felling and bucking operations. Those skilled in this art
will appreciate that where a measuring device 2 is employed
with the workhead 10, hydraulic supply lines and control
valves will also be required to activate the extension and
retraction of hydraulic actuator 9 associated with the
2170574
measuring device. The manner of making such additions to the
schematic hydraulic circuit illustrated in Figure 21 will be
apparent to those skilled in this art. As well, it will also
be apparent to those skilled in the art to adapt the
hydraulic circuit of Figure 21 for use with the more
simplified workhead according to its second embodiment, as
shown in Figures 18 to 20.
The various actuating, directional, compensating,
pressure reducing and relief valves provided in hydraulic
circuit 130, and shown circumscribed by the rectangle 153 of
Figure 21, are preferably disposed on a block manifold
located in the main body 11 of the workhead, as explained in
greater detail herebelow.
Details of the slewing means for the wrist connection 5
of the timber processing workhead according to another aspect
of the present invention are next explained with reference to
Figures 22 to 24. The slewing means comprises a slew bearing
80 having a inner ring 82 and an outer ring 84. The inner
and outer rings of the slew bearing are concentrically
arranged for relative rotational movement, by means of roller
bearings 86 or the like disposed circumferentially between
the respective mating surfaces of each of the inner and outer
rings. The inner ring 82 is fixedly attached by means of
bolts 88 or the like to a bottom slew plate 90, itself
fixedly attached to the main body 11 of the processing
workhead. The outer ring 84 of the slew bearing is fixedly
attached by means of bolts 92 or other like fastening means
to a top slew plate 94, to which mounting bracket 12 is
fixedly attached, for instance, by means of welded
engagement.
The bottom slew plate 90 and top slew plate 94 each
respectively provide centrally disposed apertures 96 and 98
to enable passage of hydraulic and electrical control lines
for the various powered devices of the processing workhead,
~_ 2170~74
32
such aæ the jaw arm pairs 21 and 31, feed rollers 36 to 39,
or saw attachment 6. The preferred means of supplying
hydraulic and electrical control lines through the wrist
connection 5 of the workhead is that of a swivel manifold
combined with a block manifold, as described in greater
detail herebelow. The top slew plate 94 further provides two
additional apertures 100 to accommodate passage of drive
means for the slew bearing 80 as next discussed.
The inside surface 102 of inner ring 82 of the slew
bearing is toothed for driven engagement with the pinion 104
provided at the terminal end of drive shaft 106 of a motor
108. A second such arrangement of pinion, drive shaft and
motor is provided radially adjacent the first drive
arrangement, the first and second motors 108 being mounted in
their respective apertures 100 provided on top slew plate 94.
Preferably, the motors 108 are in the form of reversible
hydraulic motors, which may be of the same type of hydraulic
motors described above for driving the feed rollers 36 to 39
of the processing workhead. Those skilled in this art will
appreciate that other forms of drive means could be utilized
for the slew bearing 80.
A radial protrusion or tab 110 is provided on the top
slew plate to prevent the continuous rotational movement of
the slewing means by acting as a stop means in conjunction
with a corresponding fixed engaging surface (not shown)
located on the main body of the workhead. The purpose of the
stop means is to prevent the undue entanglement or the
outright severance of electrical control lines which pass
through the slewing means by an unchecked rotation of the
workhead in the same given direction. Other stop means for
the slewing means of the workhead will be apparent to those
skilled in this art.
With reference to Figures 25 and 26, the wrist
connection 5 of the processing workhead 10 is associated with
217057~
a fluid delivery means consisting of a swivel manifold 170
for through passage of hydraulic supply lines and electrical
wiring for controlling and driving the various powered
devices of the workhead. Swivel manifold 170 comprises an
internal substantially cylindrical rotor portion 171 whose
outer surface is provided with a plurality of circumferential
fluid receiving or fluid egress channels 172a to 172d. Each
of the channels 172a to 172d is sealed by adjacently disposed
pressure seals (not shown) located in circumferential seats
173. The channels 172a to 172d are each in respective fluid
communication with corresponding through passages 174a to
174d which direct fluid flow to or from the circumferential
channels to respective interface ports 175a to 175d provided
on the underside of the rotor 171.
The rotor 171 is encased with an outer cylindrical
sleeve portion 176, whose lower terminal end 178 provides a
peripheral seat 180 therearound for receiving a sealing
means, such as an O-ring seal (not shown). To the upper
terminal ends 182 of the sleeve 176 is fixedly attached an
end plate 184. The end plate 184 provides respective top and
bottom annular channels 186 and 188 for receiving thrust
bearings (not shown), well known to those skilled in this
art. The end plate 184 has a central opening therein which
provides a seal seat 190 for receiving a sealing means (not
shown), such as an O-ring seal. Sleeve 176 is secured
against the rotor 171 by means of an end plug 192 which may
be threadedly engaged to the rotor. End plug 192 provides a
seal seat 194 on its outer surface corresponding to seal seat
190 of end plate 184. A cap plate 196 is removably attached
to rotor 171 by means of screws 198 or the like to complete
the swivel manifold assembly.
Sleeve 176 is provided with fluid inlet or outlet ports
200a to 200d which are in respective fluid communication with
the circumferential channels 172a to 172d. Each of the
circumferential channels of the rotor portion is in constant
217057~
34
fluid communication with its respective port of the sleeve
portion throughout relative rotational movement of the rotor
and sleeve. Hydraulic fluid supply or return hoses 202a to
202d are connected to the respective ports 200a to 200d
(Figure 26). The swivel manifold 170 is associated with a
fixed or block manifold 206 and is mounted thereon by means
of mounting screws 208 or the like provided through a bottom
annular connecting flange 210 of the rotor 171. The block
manifold 206 is itself fixedly mounted within the main body
11 of the workhead 10, such that the swivel manifold 170
extends outside of the main body 11 of the workhead along
slew axis BB' (Figure 4) through the respective apertures 98
and 96 of the bottom slew plate 90 and top slew plate 94
(Figure 22).
Manifold block 206 is provided with appropriate internal
passages in fluid communication with the interface ports 175a
to 175b of rotor 171. One such passage 225 is shown in
Figure 25. The internal passages are in turn in fluid
communication with a desired number of manifold inlet or
outlet ports, as at 212 and 214, for hydraulic connection to
the various devices of the workhead. For instance, outlet
port 212 of the block manifold 206 is connected to the four-
way flow diverter 136, itself connected to a plurality of
hydraulic supply hoses 216 for each of the feed roller motors
165 to 168 of the workhead 10. Inlet port 214 is for
returning hydraulic fluid from the feed roller motors.
Various actuating valves 146 and 154, flow control
valves 138, directional valves 140 and 152, pressure reducing
valves 142 and relief valves 150 of the hydraulic circuit for
the workhead 10, collectively denoted as hydraulic control
valves 224 in Figure 25, may be mounted directly onto the
underside 218 of the manifold block 206 in fluid
cor~nn;cation through the manifold block with the appropriate
interface ports 175a to 175d of the swivel manifold 170.
Where the hydraulic control valves 224 of Figure 25 are
~_ 217057~
mounted directly onto the manifold block as mentioned above,
those skilled in this art will appreciate that the various
hydraulic fluid supply and return lines traced in the
hydraulic circuit of Figure 21, and shown bounded by
rectangle 153 thereof, are provided as respective internal
passages within the manifold block 206. For instance, inlet
and outlet passages will be provided in the manifold in
respective fluid communication with inlets and outlets of the
hydraulic valves, so as to avoid the need for hose
connections to the valves.
A wiring passage 204 is provided in the rotor 171 and
end plug 192 for housing and transmission of electrical
wiring 226, which is introduced through the swivel manifold
170 by means of an aperture 220 (Figure 25) provided in cap
plate 196 along slew axis BB' (Figure 4). As well,
electrical wiring received from passage 204 of the swivel
manifold may be passed through the manifold block 206 for
connection to an electrical terminal strip 222 which may also
be mounted on the underside 218 of manifold 206.
By furnishing a larger surface area for the various
hydraulic and electrical connections, accessibility for
maintenance purposes is enhanced by use of the manifold block
206. As well, by providing a swivel manifold in conjunction
with a block manifold, hydraulic supply hoses to the workhead
10 may be shortened, since there is no need for the
rotational movement of the wrist connection to be
accommodated by slack in the supply hoses. This results in a
compact design which minimizes hose chaffing and snagging
during field use of the workhead 10.
Finally, those skilled in this art will appreciate that
the inventive concept in any of its foregoing aspects can be
incorporated, adapted or modified in many different
constructions, so that the generality of the preceding
description is not to be superseded by the particularity of
2170574
the attached drawings. Thuæ, various alterations,
modifications and/or additions may be incorporated into the
various constructions and arrangements of parts and devices
described herein without departing from the spirit or scope
of the present invention.
