Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
lZ~)9448
This invention relates to an automatic lopping
machine for removing or lopping branches from the trunks of
standing, living trees to a certain height from the ground.
There has been proposed an automatic lopping
machine comprising a main body including a plurality of
drive wheels, each adapted to be driven in a plane inclined
to the trunk of a st~n~ing, living tree, and an endless
chain saw adapted to be driven generally in a vertical
direction, and an auxiliary unit including a plurality of
idle wheels and adapted to be connected to the main body so
as to encircle the tree trunk with the main body and the
auxiliary unit positioned on respective sides of the tree
trunk. When in use, the machine ascends the tree while
revolving around the tree trunk depicting a helical path,
and at this time, the chain saw cuts branches from the trunk
at a lea~; ng run thereof with respect to the direction of
travel of the chain saw.
The known lopping machine requires the use of
separate drive units, one for driving the drive wheels and
the other for driving the chain saw, and the consequent use
of separate reduction units and separate power transmission
trains. Therefore, the known lopping machine is bulky,
heavy and complicated, and is difficult to operate and
handle. In addition, the known lopping machine is
susceptible to frequent malfunctioning.
In addition to these disadvantages in that, since
component parts of the drive system for each of the drive
,
~,,.
, , ! ~ ., ,
,, .
12C~9448
2 --
-- 2
units and also for the chain saw are exposed to the outside
without being shielded, not only does the trunk of a tree
tend to be damaged and/or unnecessarily scraped, but also
branches tend to be dragged in between some component parts
S of the drive system to such an extent as it may result in
breakage of the chain saw and/or jamming of the drive
system.
Accordingly, this invention has been developed
with a view to substantially eliminating the above described
disadvantages and inconveniences inherent in the known
lopping machine and has for its essential object to provide
an improved lopping machine of a type compact in structure,
lightweight and easy to operate and hAndle.
In order to accomplish this and other objects of
this invention, this invention pertains to an improved
lopping machine effectively utilizable for pruning purpose.
The machine according to this invention comprises a main
body including a plurality of drive wheels, each adapted to
be driven in a plane inclined relative to the trunk of a
standing, living tree, and a vertically drive chain saw, and
an auxiliary unit including a plurality of idle wheels and
adapted to be coupled to the main body by means of spring-
connected fastening elements. The lopping so far described
operates in a manner similar to the known machine, i.e.,
ascends the tree while revolving helically around the tree
trunk with the drive and idle wheels contracting the
periphery of the tree, and with the leading run of the chain
1;i~448
-- 3 --
saw cutting branches off from the tree trunk. In accordance
with this invention, the lopping machine o~ the type
referred to above is provided with a single, common drive
unit, for example, a gasoline or diesel engine, having its
S drive shaft operatively coupled to the chain saw for driving
the latter at a high speed and also to the drive wheels
through a reduction gear unit for driving the drive wheels
at a reduced speed.
Since this invention is featured in the use of the
single drive unit for both the chain saw and the drive
wheels, the drive system as a whole can be simplified,
making it possible to manufacture a compact, lightweight
inexpensive lopping machine. In addition, since a power
transmission system including endless belts or chains for
driving the drive wheels is disposed downwardly of the drive
wheels with respect to the direction in which the -chine
ascends the tree, the possibility of branches being dragged
or jammed into the drive system can advantageously be
minimized, thereby rendering the machine as a whole easy to
h~n~le and reliable in operation.
Moreover, since the lopping machine according to
this invention is lightweight and compact as hereinbefore
described, one can carry it on the bar for the
transportation to the site of pruning with no difficulty,
and the fitting to and removal from the tree trunk can also
be performed easily and efficiently in ~in; zed execution
time.
$2~944~
The lopping machine embodying this invention can
be used for removing branches from the tree all the way from
an area corresponding to the trunk diameter of about 25cm
measured at the waist level to an area corresponding to the
trunk diameter of about 8cm. In typical applications, the
time required to complete the pruning work per tree is
generally 5 minutes or less, and one lopping machine of this
invention has a capability comparable to the amount of labor
of 2.5 persons or more and, therefore, one attendant worker
can handle two lopping machines per unit time of work.
These and other objects and features of this
invention will readily be understood from the following
description taken in conjunction with a preferred embodiment
with reference to the accompanying drawings, in which:
Fig. 1 is a schematic side view of a lopping
machine according to a preferred embodiment of this
invention, the machine being shown as set in position to the
trunk of a tree;
Fig. 2 is a schematic top plan view of a portion
of the machine of Fig. l;
Fig. 3 is a view similar to Fig. 2, showing the
condition the machine assumes during its descending motion
down the tree;
Fig. 4 is a side view, on an enlarged scale, of a
portion of the machine;
Fig. 5 is a front elevational view of a main body
of the machine;
lZ~g448
- 5 --
Fig. 6 is a side elevational view of the machine
main body;
Fig. 7 is a cross-sectional view taken along the
line A-A in Fig. 5;
Fig. 8 is a rear elevational view of the machine
main body with a portion removed;
Fig. 9 is a view similar to Fig. 6, showing the
main body descen~;ng the tree;
Fig. 10 is a block diagram showing a drive system
employed in the machine of this invention;
Fig. 11 is an explanatory diagram used to explain
the drive system shown in Fig. 10;
Fig. 12 is a block diagram showing an engine
control system used in the machine of this invention;
Fig. 13 is a block diagram showing a fluid circuit
for oiling;
Fig. 14 is a diagramatic representation of Fig. 2;
Fig. lS is a sectional view of one of the drive
wheels used in the machine of this invention;
Fig. 16 is a cross-sectional view taken along the
line C-D in Fig. lS;
Fig. 17 i~ a perspective view of an endless chain
saw used in the machine of this invention;
Fig. 18 is a front elevational view, on a somewhat
enlarged scale, of a portion of the chain saw;
Fig. 19 is a top plan view of Fig. 18
lZQ~448
-- 6 --
Fig. 20 is a view similar to Fig. 18, showing a
guide element in a different operative position;
Fig. 21 is a view similar to Fig. 21, showing the
manner in which the chain saw is laterally displaced;
Fig. 22 is a sectional view of a reel release
mechanism used in the machine of this invention;
Fig 23 and 24 are views similar to Fig. 22,
showing the reel release mechanism in different operative
positions, respectively;
Fig. 25 is a front elevational view of an
auxiliary unit of the machine of this invention;
Fig. 26 is a top plan view of the machine
auxiliary unit shown in Fig. 25;
Figs. 27 and 28 are views substantially similar to
Fig. 25, showing idle wheels assuming different positions,
respectively;
Fig. 29 is an explanatory diagram used to explain
the descen~i ng motion of the machine down the tree;
Fig. 30 is a perspective view of a table to be
used to support the machine main body at the time of setting
of the machine to the tree trunk;
Fig, 31 is a schematic side view of a manipulating
rod to be used in conjunction with the machine of this
invention;
Fig. 32 is a view similar to Fig. 11, showing a
modification; and
lZ~gg48
Figs. 33 and 34 are schematic dlagrams showing a
remote control unit for operating the reel release
mechanism, the reel release mechanism being shown in
different operative positions, respectively.
Before the description of this invention proceeds,
it should be noted that like parts are designated by like
reference numerals throughout the accompanying drawings.
Referring first to Fig. 1, a lopping machine
according to this invention, generally identified by X,
comprises a main body I including an engine 1, a plurality
of, for example, four, drive wheels 2a, 2b, 2c and 2d, an
endless chain saw 3, and a retractable idle roller 4, and an
auxiliary unit II removable connectable to the main body I
and including a plurality of, for example, six, idle wheels
Sa, 5b, 5c, Sd, 5e and 5f.
The main body I comprises a framework 6 having the
engine 1 rigidly mounted on the back thereof and also having
upper and lower pairs of the drive wheels 2a, 2c and 2b, 2d
arranged on the front thereof 80 as to partly protrude
outwards for driving engagement with the peripheral surface
of a tree trunk W in a manner as will become apparent from
the subsequent description. The framework 6 also has a
guide plate 7 mounted on the top thereof for guiding the
chain saw 3, and carries the retractable idle roller 6
supported at the front thereof for movement between
projected and retracted position.
lZQ~448
As best shown in Fig. 5, the framework 6 is
fabricated from lengths of ste~1 piping 8 so bent and so
connected so as to give a shape substantially similar to a
lattice or junglegym. The framework 6 has a carrier plate 9
rigidly secured to a rear central portion thereof as shown
in Fig. 8, the engine 1 being mounted on the framework 6
through the carrier plate 9. The framework 6 also has upper
and lower pairs of bearing studs lOa, lOc and lOb, lOd
rigidly secured to and extending outwardly from four corner
portions of the framework for the support of the associated
pairs of the drive wheels 2a, 2c and 2b, 2d. The guide
plate 7 for the chain saw 3 mounted on the front top of the
framework 6 is secured at two points to a lower bearing boss
11, provided on the carrier plate 9, and an upper bearing
boss 13 mounted on the upper right-hand bearing stud through
an upper covering 12. The retractable idle roller 4 is
disposed in a window defined at 6a in the framework central
portion thereof and is rotatably carried by a support lever
14 of a generally L-shaped configuration. A pair of bearing
sleeves 16a and 16b are rigidly secured to the framework 6
for receiving therein and guiding associated side rods 15a
and 15b exte~ing from the auxiliary unit II in parallel and
laterally spaced relation to each other. Rigidly secured to
and exte~lng outwardly from the front four corners of the
framework 6 is hook members 18a, 18b, 18c and 18d over which
respective lengths of chains 17a, 17b, 17c and 17d connected
to~the auxiliary unit II through tension springs 83a, 83b,
lZ~448
83c and 83d are engaged when the machine of this invention
is set around the tree trunk W.
The engine 1 is used to drive the drive wheels 5a
to 5d and, also, a saw chain 19 constituting the chain saw 3
and may be either a gasoline engine or a diesel engine. A
housing 22 for the engine 1, in which a speed regulating
governor 20 and a ce~ntrifugal clutch 21 are incorporated, as
shown in Fig. 10, has a flange 23 through which the housing
22 with the engine 1 therein is rigidly secured to the
carrier plate 9 as best shown in Fig. 6. A drive shaft 24
extending outwardly from the centrifugla clutch 21 in turn
extends frontwardly ~rom the framework 6 with its free end
having a sprocket wheel 25 mounted thereon for rotation
together therewith, said sprocket wheel 25 being used to
drive the saw chain 19, which is trained between the
sprocket wheel 25 and the guide plate 7. For driving the
drive wheels 2a to 2d, the drive shaft 24 is also drivingly
coupled thereto through a reduction gear unit 26 as shown in
Fig. 10. The reduction gear unit 26 is rigidly mounted on
the rear top of the framework 6 as shown in Fig. 8 and is
drivingly connected with the drive shaft 24 through an
endless drive chain 27. This reduction gear unit 26 has a
drive output ~haft 28 extending thereacross, an upper end
28a of which is drivingly coupled to the upper pair of the
drive wheels 2a and 2c through respective endless chains 29a
and 29c, while the opposite, lower end 28b of said drive
output shaft 28 is drivingly coupled to the lower pair of
12~9448
-- 10 --
the drive wheels 2b and 2d through respective endless chains
29b and 29d by means of an intermediate transmission system
including two universal joints 30 on the opposite ends of a
connecting rod 31. The governor 20 for the engine 1 is so
designed and so operable as to regulate the speed of
rotation of the drive shaft 24 to a lower value to permit
the engine 1 to withstand a high load.
The centrifugal clutch 21 for the engine 1 serves
to couple and decouple the drive shaft 24 to and from the
engine 1 and also to operate a reel release mechanism in a
nner which will be described later when it is in
decoupling position, i.e., in position to decouple the drive
shaft 24 from the engine 1. The drive unit including the
engine 1 also includes, as Qhown in Fig. 13, an automatic
oiling device 33 for oiling pistons, bearings, a chain saw
bax, the reduction gear unit 26, the chains 29a to 29d and
other movable parts, and is provided with an electric
control circuit 34, as shown in Fig. 12, for controlling the
start and interruption of the engine 1, which electric
control circuit 34 includes a timer 35, a remote control
~witch 36 and an overload safety device 37 for bringing the
engine 1 to a halt in the event of the occurrence of
overload.
The drive wheels 2a to 2d are rotatably mounted on
the bearing studs lOa to lOd by means of axles 38a, 38b, 38c
and 38d, respectively, for rotation in a plane inclined at a
predetermined angle, for example, 20, relative to the
vertical. In other words, when viewed form the front of the
framework 6 as shown in Fig. 5, all of the drive wheels 2a
to 2d are so supported and so positioned on the bearing
studs lOa to lOd by means of the axles 38a to 38d,
respectively, that the plane of rotation of each of the
drive wheels 2a to 2d can lie in a plane inclined downwardly
from the left-hand top portion of the drawing of Fig. 5 at a
predetermined angle, for example, 20, relative to the
horizontal plane, i.e., the plane generally parallel to the
ground surface. The axles 28a to 28d of the respective
drive wheels 2a to 2d mounted on the associated bearing
studs lOa to lOd fast with the framework 6 are, when viewed
from the top of the framework 6 as shown in Figs. 2 to 14,
located in the same plane at the front of the framework 6
lS such that the drive wheels 2a to 2d partly protrude an equal
distance outwardly from the front of the framework 6 for
engagement with the peripheral surface of the tree trunk W.
The greater the distance between the upper and lower pairs
of the drive wheels 2a, 2c, and 2b, 2d is, the more the
travel of the machine X along the tree trunk W is
stabilized. However, the smaller the distance between the
drive wheels 2a and 2b and the drive wheel 2c and 2d is, the
smaller the radius of gyration of the machine.
When the machine ~ is set in position around the
tree trunk W, the drive wheels 2b, 2c and 2d directly
contact the peripheral surface of the tree trunk W, but the
drive wheel 2a contacts it through an opening 39 defined in
12~9448
a lower central portion of the guide plate 7 for the chain
saw as seen from Fig. 5.
The opposite ends of each of the axles 38a to 38d
of the associated drive wheels 2a to 2d is journalled by the
respective bearing stud lOa, lOb., lOc or lOd, and the
chains 29a to 29d for driving the respective drive wheels 2a
to 2d are disposed beneath the drive wheels 2a to 2d as if
the drive wheels 2a to 2b serve for the associated claims
29a to 29d a pro- tective shield necessary to avoid
entanglement or jamming of branches into the path of travel
of the chains 29a to 29d from above. As best shown in Fig.
15, each of the drive wheels 2a to 2d is in the form of a
tire wheel 40 comprising a metal ring 41 having a plurality
of circumferentially equally spaced metal fins 42 integral
therewith and exte~ing an equal distance radially outwardly
therefrom, the space between the adjacent two of these metal
fins 42 being filled up with rubber material 43 to make up
the wheel having a continuous, smooth and arcuately
sectioned outer periphery as shown in Fig. 16. In this
construction, each of the drive wheels 2a to 2d has a highly
improved durability and, also, can exert a high frictional
force when contacting the peripheral surface of the tree
trunk without substantially giving damage to the bark.
Specifically, the greater the outer diameter of each drive
wheel, the higher the force of friction. However, the
smaller the outer diameter thereof, the smaller the radius
of gyration of the machine X.
12Q9448
- 13 -
Portions of the drive wheel 2b and 2d opposite to
the portions thereof which protrude outwards from the front
of the framework 6, and the associated chains 29b and 29d
trained around the respective axles 38b and 38d are both
protected by a lower covering 44 secured to a rear lower
portion of the framework 6 and extending generally downwards
therefrom. An upper covering 12 secured to a r~ar upper
portion of the framework 6 overhangs portions of the drive
wheels 2a and 2c opposite to the portions thereof which
protrude outwards from the front of the framework 6, the
associated chains 29a and 29c trained around the respective
axles 38a and 38c, the reduction gear unit 26 and the engine
1. The reduction gear unit 26 is also covered at its front
portion by a front covering 45 secured to a front upper
portion of the framework 6.
In addition to the saw chain 19 trained between
the guide plate 7 and the sprocket wheel 25, and a support
means including the upper and lower bearing bosses 11 and 13
for connecting the guide plate 7 to the framework 6, the
chain saw 3 includes a guiding means including a guide
roller 46 for trapping and guiding tree branches towards the
saw chain 19, a spacer means arranged at upper and lower
portions of the guide plate 7 for keeping a distance between
the periphery of the tree trunk and the saw chain 19, and a
pair of elongated side covers 47a and 47b covering the
trailing run of the saw chain 19 with respect to the
direction of travel of the saw chain 19. The guide plate 7
448
- 14 -
is in the form of a high strength metal plate and is so
mounted and so positioned on the framework 6 so as to
project upwardly from the framework 6 while lying in a plane
spaced a slight distance frontwardly from the framework 6
and generally in parallel relation to the front of the
framework 6. With the guide plate 7 so mounted in the
manner described above, the leading run l9a of the saw chain
19 extends upwardly between the upper pair of the drive
wheels 2a and 2c and faces in a direction towards the
direction of revolution of the machine X around the tree
trunk during the ascending motion thereof.
The guide plate 7 has a generally egg-shaped
configuration and has the opening 39 defined at a lower
central portion thereof, through which opening 39 the drive
wheel 2a projects partly outwards for the purpose which has
been described hereinbefore. ~s best shown in Fig. 7, the
peripheral edge of the guide plate 7, except for a lower end
portion thereof confronting the sprocket wheel 25, is so
shaped into a yenerally V-shaped section so as to define a
guide groove 48 along which the saw chain 19 travels. This
guide plate 7 is pivotable about a common axis passing
through the bearing bosses 11 and 13 and, for this purpose,
has a pair of spaced beaxing bushings 49 and 50 for
receiving therein the bearing bosses 13 and 11,
respectively. The bearing bosses 11 and 13 are carried on
above the other by the framework 6 with their longitudinal
axis aligned with each other, the lower bearing boss 11
~20S~48
- 15 -
being rigidly mounted on the carrier plate 9 while the upper
bearing boss 13 is rigidly mounted on a fixture 51 which is
in turn adjustably mounted on the upper cover 12.
Accordingly, the guide plate 7 is pivotable about the axis
common to the upper and lower bearing bosses 13 and 14, but
is normally biased by a tension spring 52 in one direction
about the previously mentioned common axis with the trailing
run of the saw chain 19 close towards the upper cover 12.
The guide plate 7 so biased is held in one position defined
by a stopper 53 to which a left-hand side portion of the
guide plate 7 as viewed in Fig. 5 abuts.
The saw chain 19 trained between the guide plate 7
and the sprocket wheel 25 on the drive shaft 24 is adapted
to be driven in one direction with its le~ding and trailing
runs l9a and l9b situated on right-hand and left-hand sides`
of the guide plate 7, respectively, as viewed in Fig. 8, the
leading run l9a of the saw chain 19 being utilized for
lopping branches off the tree trunk W. Preferably, the top
of the guide plate 7 corresponding in position to the
boundary between the le~ g and trailing runs 19a and l9b
is so shaped so as to point towards the guide roller 46 for
the purpose of facilitating the entry of each tree branch to
be cut in between the roller 46 and the le~fling run l9a of
the saw chain 19. In addition, the opposite ends of the
guide groove 48 defined in the portion of the peripheral
edge of the guide plate 7 are pre- ferably enlarged
IZ0~4~8
- 16 -
outwardly to facilitate the entry and exit of the saw chain
19 being driven in one direction.
The guide means referred to above comprises a
support arm 55 rigidly mounted on the top of the guide plate
7 and situated on one side of the guide plate 7 opposite to
the tree, a first pivotable lever 56 mounted on the support
arm 55 for pivotal movement through a predetermined angle, a
second pivotable lever 57 mounted on the first pivotable
lever 56 for pivotal movement through a predetermined angle,
a biasing spring 58, for example, a tension spring, for
biasing the second pivotable lever 57 in a direction
counterclockwise as viewed in Fig. 8, a generally sector-
shaped roller 59 made preferably of synthethic resin and
rotatably mounted on the first pivotable lever 56, and a
stopper 60 for the first pivotable lever 56. The guide
roller 46 also constituting a part of the guide means is
preferably made of synthetic resin and is rotatably mounted
on the second pivotable lever 57 at one end thereof opposite
to the first pivotable lever 56. The ~ector-shaped roller
59 has its arcuate peripheral portion protruding upwardly
outwards from the top perimeter of the guide plate 7 and
serves to avoid any undesirable contact of each tree branch
with a portion of the saw chain 19 turning around the top of
the guide plate 7.
The guide roller 46 mounted on the second
pivotable lever 57 as hereinbefore described ha~ its
peripheral portion protruding outwards from the path of
12~448
- 17 -
travel of the leading run l9a of the saw chain 19 so as to
to draw each tree branch inwardly between the roller 46 and
the leading run l9a of the saw chain 19. More specifically,
the guide means is so designed and so positioned relative to
the guide plate 7 that, as the tree branch enters in between
the roller 46 and the leading run l9a of the saw chain 19
when the machine X ascends the tree trunk W while spirally
revolving therearound, the roller 46 can be angularly
upwardly shifted against the spring 58 together with the
first and second pivotable levers 56 and 57 as shown in Fig.
20 while forcing the tree branch towards the leading run l9a
of the saw chain 19, but as the tree branch relatively rolls
over roller 46 during the ascending motion of the machine X
revolving spirally therearound, the first pivotable lever 56
can be biased by the spring 58 to make the machine X as a
whole forced downwards together with the roller 46 to let
the tree branch pass over the sector-shaped roller 59
without contacting the chain 19 as shown in Fig. 18. In
this way, the guide means, particularly the guide roller 46,
discriminates the tree branch located at a height within the
reach of the chain saw 3 and that at a height outside the
reach of the same, and the tree branch at a height within
the reach of the chain saw 3 can be guided by the guide
roller 46 towards the saw chain 19, but the tree branch at a
height outside the reach of the chain saw 3 is allowed to
pass over the guide roller 46 and, then, the sector-shaped
448
- 18 -
roller 59 for the next succeeding turn of the machine X to
cut it from the tree trunk W.
~ he spacer means referred to hereinbefore
comprises, as best shown in Fig. 6, lower and upper leg
members 62 and 63 each having a predetermined length. The
lower leg member 62 is rigidly mounted on a plate piece 61
secured to a rear lower portion of the guide plate 7 and
protruding a predetermined distance frontwardly from the
guide plate 7. The upper leg member 63 is secured coaxially
to the guide roller 46 and protruding a predete ined
distance frontwardly of the guide plate 7 and in a direction
towards the tree. When the machine X is in use the
respective tips of the leg members 62 and 63 slidingly
contact the peripheral surface of the tree trunk W, keeping
the chain saw 3 spaced a i ni i zed distance from the
peripheral surface of the tree trunk W.
The retractable idle roller 4 operable when the
machine X which has ascended to a predetermined or desired
height above the ground is desired to descend the tree trunk
20 i8 rotatably carried by a support lever 14 which is in trunk
pivotally mounted at a substantially intermediate portion
thereof on the framework 6. One end of the support lever 14
opposite to the idle roller 4 loosely extends through the
framework 6 and terminates outside the framework 6 for the
access to an operator of the machine X as best shown in
Figs. 1, 6, 9 and 29. When the free end of the lever 14
opposite to the idle roller 4 is pulled downwards in a
448
direction shown by the arrow in Fig. 29, the idle roller 4
which has been held in the retracted position, as shown in
Figs. 1 and 6, is brought to the projected position as shown
in Fig. 29, contacting the peripheral surface of the tree
trunk W while separating the drive wheels 2a to 2d from it.
In this way, when the free end of the lever 14 is pulled
downwards, the machine X can descend straight the tree trunk
W with the idle wheels 5a to Sd and the idle roller 4 freely
rolling along the tree trunk W. To keep the idle roller 4
in the retracted position, a biasing spring 64 is employed
and disposed between a portion of the framework 6 and a
portion of the lever 14 on one side remote from the roller 4
so as to bias the lever 14 in a direction counterclockwise
as viewed in Figs. 1, 6 and 9. For the purpose which will
be described later, a pull cable 65 is connected to the free
end of the lever 14. In practice, unless the machine X
having ascended is desired to be recovered down the tree
trunk W, the pull cable 65 is wound around a reel 32, and
the reel 32 is in turn releaseably connected to the
framework 6 through a reel release mechanism in a manner
which will now be described.
As best shown in Fig. 22, the reel release
mechanism is operatively associated with the centrifugal
clutch 21 and comprises an operating plate 68 having a first
carrier pin 69 rigidly secured thereto and engageable in a
hole 67 defined in an arm 66 integral with and extending
outwardly from the reel 32. The operating plate 68 is so
~209448
20 -
operatively coupled to the clutch 21 through a connecting
lever 54. The reel release mechanism is so designed that,
so long as the engine 1 has not yet been operated, the first
carrier pin 69 can be engaged in the hole 67 in the reel 32
by the action of a spring 70 incorporated in the clutch 21,
thereby holding the reel 32 in an elevated position, as
shown in Fig. 23, but when the clutch 21 is operated as a
result of the rotation of the engine 1, a second carrier pin
72 rigidly secured to the operating plate 68 can be moved
into the hole 67 in the reel 32 by the action of a
compression spring 71 while pushing the first carrier pin 70
out of the hole 67, thereby allowing the reel 32 to be
carried in a lowered position by the second carrier pin 72
as shown in Fig. 24. Starting from this condition, i.e.,
while the reel 32 is carried by the second carrier pin 72
then projecting into the hole 67, the subsequent stop of the
engine and, hence, the interruption of operation of the
clutch 21, results in that the connecting lever 54 is
displaced rightwards, as viewed in Fig. 23, by the action of
the spring 70 in the clutch 21, caUcing the operating plate
68 to pivot counterclockwise, as viewed in Figs. 23 and 24,
against the compression spring 71 with the second carrier
pin 72 consequently disengaged from the hole 67 in the reel
32. When this occurs, the reel 32 is released from the
machine X and falls by its own gravity onto the ground or
down to an appropriate height above the ground, delivering
the pull cable 65 to a position conveniently accessible to
12(~448
21 -
the machine operator. As hereinbefore described, when the
machine operator pulls the pull cable 65 downwards, the
machine X, having ascended the tree trunk W, can be drawn
down the tree trunk while the idle wheels 5a to Sf and the
idle roller 4 roll along the tree trunk W.
As hereinbefore described, in order for the
machine X to be set to the tree trunk W, the main body I and
the auxiliary unit II must be connected together. This
connection can be accomplished by inserting the side rods
15a and l5b through the respective bearing sleeves 16a and
16b and then through bearing sleeves 81 in the auxiliary
unit II and engaging the connecting chains 17a to 17d over
the respective hook members 18a to 18d fast with the
framework 6 while the tension springs 83a to 83d are pulled
axially outwards. Depending on the extent to which the
springs 83a to 83d are pulled axially outwardly, the force
necessary for the main body I and the auxiliary unit II to
clamp the tree trunk W from the opposite directions towards
each other can be adjustable. When and so long as the
machine X is set in position around the tree trunk W, the
drive wheels 2a to 2d and at least the idle wheels 5a to 5d
contact the tree trunk W under pressure. The idle wheels 5e
and 5f may not alway~ contact the tree trunk, dependi~g on
the diameter of the trunk, but may be brought into contact
therewith as the machine X ascends the tree trunk W to a
height where the diameter of the tree trunk is small.
.
~2Q~448
- 22 -
Hereinafter, the details of the auxiliary unit II
will be described with particular reference to Figs. 1, 2, 3
and 25 to 28.
The auxiliary unit II comprises an auxiliary
framework 82 carrying the upper and lower rows, the idle
wheels 5a, 5c, 5e and 5b, 5d, 5f, the bearing sleeves 81 for
receiving therein the side rods 15, and cylindrical spring
casings 84a, 84b, 84c and 84d. The spring casings 84a to
84d accommodate therein the corresponding tension springs
83a to 83d, each having one end rigidly secured to a closed
end of the respective spring casing 84a, 84b, 84c or 84d and
the other end connected with the respective connecting chain
17a, 17b, 17c or 17d situated outside the spring casing.
The auxiliary framework 82 is fabricated from lengths of
high strength steel piping and includes a pair of spaced
columns 82c and 82d and upper and lower beams 82a and 82b
rigidly secured at both ends to and exte~jng between the
columns 82c and 82d 50 as to represent a generally
rectangular configuration. As best shown in Fig. 25, the
bearing sleeves 81 are rigidly secured to substantially
intermediate portions of the columns 82c and 82d,
respectively, so as to extend at right angles thereto, and
the spring casings 84a and 84b are rigidly ~ecured to the
opposite ends of the column 82c, respectively, so as to
extend at right angles thereto while the spring casings 84c
and 84d are rigidly secured to that of the column 82d,
respectively, so as to extend at right angles thereto. It
~2Q~448
- 23 -
is the upper an lower beams 82a and 82b on which the upper
and lower rows of the idles wheels 5a, 5c, 5e and 5b, 5d, 5f
are rotatably mounted by means of brackets identified
generally by 85.
Each of the idle wheels 5a to 5f is preferably
made of synthetic resin and is in the form of a caster
wheel. Each idle wheel Sa, 5b, 5c, 5d, 5e or 5f is
rotatably mounted by means of a respective axle member 86 on
the associated bracket 85 which is in trunk mounted on the
beam 82a or 82b by means of a corresponding shaft 87. The
shaft 87 for each of the wheels 5a to 5f extends through the
respective beam 82a or 82b for rotation about its own
longitudinal axis through a limited angle and, for this
purpose, as best shown in Figs. 27 and 28, a cam plate 88,
cooperable with a stop pin 89 secured to the beam 82a or 82b
so as to protrude towards the associated bracket 85, is
rigidly mounted on the shaft 87 for each idle wheel 5a, 5b,
5c, 5d, 5e or Sf. Specifically, the cam plate 88 and the
stop pin 89 are 80 designed and so positioned relative to
each other that, during the ascending motion of the machine
X in the manner as hereinbefore described, the respective
idle wheel can rotate in contact with the tree trunk about
the axle member 86 in a plane inclined a certain angle to
the tree trunk and generally equal to the angle of
inclination of the drive wheels 2a to 2d as shown in Fig. 27,
but during the descending motion of the machine X moving
generally straight down the tree trunk, such idle wheel can
lZ09448
- 24 -
rotate in contact with the tree trunk in a plane generally
parallel to the vertical or the longitudinal axis of the
tree trunk as shown in Fig. 28.
The lopping machine X of the construction
5 described hereinabove can be set in position around the tree
trunk in the following manner and operate in the following
~nner.
At the outset, the main body I and the auxiliary
body II should be plated on respective sides of the tree
trunk W having branches to be removed, in a manner with the
drive wheels 2a to 2d and the idle wheels Sa to Sf facing
the tree trunk W. Then, the side bars lS should be inserted
through the bearing sleeves 81 and the bearing sleeves 16a
and 16b so as to extend between the main body I and the
lS auxiliary unit II, thereby keeping the main body I and the
auxiliary unit II in right position relative to the tree
trunk W. ~hereafter, the connecting chains 17a to 17d
should be pulled one at a time against the associated
springs 83a to 83d and, then, hooked to the associated hook
members 18a to 18d while they are still pulled against the
springs 83a to 83d, to connect the main body I and the
auxiliary unit II together, thereby completing the setting
of the machine X around the tree trunk W.
It is to be noted that, at the time of completion
~5 of the setting of the machine X, the idle wheels 5e and Sf
located inte_ ?di~tely between the idle wheels 5a and 5c and
.between the idle wheels 5b and Sd, respectively, may not
120~448
- 25 -
contact the tree trunk W depending on the diameter of that
portion of the tree trunk at which the machine is set. In
such case, the idle wheels 5e and 5f can be brought into
contact with the tree trunk as the machine X ascends the
tree trunk to a height where the diameter thereof becomes
small. In any event, in order to avoid any possible
slippage of the machine relative to the tree trunk which
would be likely to occur when the machine X has ascended the
tree trunk to a certain height, it is preferred that each of
the intermediate idle wheels 5e and 5f has a width greater
than that of any other idle wheels Sa to Sd as best shown in
Fig. 25 to 28. In addition, since there is the possibility
that the machine X ascending the treé trunk may slip
downward when the diameter of the tree trunk becomes smaller
than the diameter of the imaginary circle defined by and
enclosed by the wheels 2a to 2d and 5a to 5f, not only is
the employment of the intermediate idle wheels 5e and 5f of
increased width preferred, but also, the number of each row
of the idle wheels on the auxiliary framework 82 of the
auxiliary unit II may be increased as shown by 5g in
Fig. 14.
After the setting of the machine, the engine 1 is
to be started to drive both the drive wheels 2a to 2d and
the chain saw 3. As the drive wheels 2a to 2d are driven,
the machine X ascends the tree trunk W while revolving
spirally around the tree trunk W. The angle of the helix of
the path along which the machine X moves revolving around
12Q~448
the tree trunk W corresponds to and is determined by the
angle of inclination of the drive wheels 2a to 2d. At the
same time, the chain saw 3 is driven with its leading run
l9a travelling downwards on one side facing the direction in
which the machine X is helically moved about the tree trunk
W. When the chain saw 3 approaches a branch extending
laterally from the tree trunk W, and if such branch is
within the reach of the chain saw 3, the guide roller 46 is
upwardly shifted together with the first and second
pivotable levers 56 and 57 in contact with the tree branch,
drawing the latter in between the roller 46 and the leading
run l9a of the saw chain 19. In this way, during the
continued helical revolution of the machine X, the tree
branch is cut from the tree trunk W. However, if the branch
is still located outside the reach of the chain saw 3 even
though it contacts the guide roller 46, the guide roller 46
and, hence, the machine X as a whole, is downwardly forced
into contact with the branch to let the latter pass over the
guide roller 46 and, then, over the sector-shaped roller 59.
Thi~ tree branch can, however, be cut from the tree trunk W
during the next succeedi ng turn of the machine around the
tree trunk W.
It is to be noted that, because of the employment
of the spacer means comprised of the spaced leg members 62
and 63, the chain saw 3 is kept a predetermined distance
from the peripheral surface of the tree trunk W all the way
during the asce~i ng motion of the machine. This is true
lZ~448
- 27 -
even where, at a certain height, the tree trunk has a
varying radius due to the presence of, for example, a
lateral protuberance as shown by W' in Fig. 19. This is
because the spring 52 serves to bias the guide plate 7 in
one direction about the common axis of the bearing bosses 13
and 11 with the tips of the leg members 62 and 63 held
constantly in sliding contact with the peripheral surface of
the tree trunk W. It is also to be noted that the angle of
inclination of the guide plate 7 and, hence, the chain saw
3, relative to the longitudinal axis of the tree trunk can
be adjusted by adjusting the position of the fixture 51 for
the upper bearing boss 13.
As the machine X ascends the tree trunk to a
certain height above the ground, and with the trunk W
decreasing, the springs 83a to 83d in the auxiliary unit II
pull the associated connecting chains 17a to 17d in a
direction inwardly of the spring casing 84a to 84d and,
therefore, the main body I and the auxiliary unit II are
still held in position to hold the trunk W therebetween.
Upon expiration of a preset time set in a timer 35 shown in
Fig. 12, with the engine 1 consequently brought to a halt,
or when the engine 1 is brought to a halt by manipulating a
remote-controlled switch 36, both the drive wheels 2a to 2d
and the chain saw 3 are brought to a halt. At the same
time, the centrifugal clutch 21 is also brought in an
inoperative position and the reel 32 is, therefore, released
from the main body I. When the pull cable 65 is pulled
~20~448
- 28 -
downwards after the reel 32 has dropped from the machine X,
the lever 14 is pivoted to bring the retractable idle roller
4, which has been held in the retracted position, to the
projected position as shown in Fig. 29 and the machine X
starts descending by its own gravity generally straight down
the tree trunk W. During the descending motion of the
machine, the idle wheels 5a to 5f are pivoted in contact
with the tree trunk to assume a vertical position at which
they rotate in a plane generally parallel to the vertical.
In practice, several pulls of the pull cable 65 may be
required to bring the machine X completely down to the
ground where the operator can remove the machine X from the
tree trunk W for the next succeeding cycle of work. In such
case, the machine X descends intermittently because, each
time the pull cable 65 is released, the retractable idle
roller 4 is retracted, allowing the drive wheels 2a to 2d to
contact the tree trunk W ~y the action of the springs 83a to
83d. Alternatively, the pull cable 65 may be continuously
pulled by using both hands alternately in quick succession
to allow the machine X to descend generally continuously.
After the machine X has descended, the
disengagement of the chains 17a to 17d from the hook members
18a to 18d and the subsequent removal of the side rods 15
separate the main body I and the auxiliary unit II from each
other in readiness for the transportation to the next site
of pruning.
~20~448
- 29 -
In view of the fact that the main body I has a
substantial weight while the auxiliary unit II is
lightweight, the use of a support table such as shown by 90
in Fig. 30 appears desirable where the machine X is desired
to be set to the tree trunk at a height corresponding to the
waist-level of the operator. The support table 90 shown in
Fig. 30 is, as can readily be understood by those skilled in
the art, mountable removably to the tree trunk in a manner
as shown for the support of the main body I thereon.
Shown in Fig. 31 is a manipulating rod 91, an
accessory to the machine X, which may be used to manipulate
the lever 14 exteriorly to forcibly bring the retractable
idle roller 4 into the projected position and thence, to
draw the machine X downwards in the event of the occurrence
of any trouble in the machine X.
From the foregoing description, it has now become
clear that, since the drive shaft 24 of the engine 1 is
operatively coupled to both the saw chain 19 through the
sprocket wheel 25 mounted thereon and the drive wheels 2a to
2d through the xeduction gear unit 26 by means of the
universal joints 30 and the drive chains 29a to 29d, the
drive system of the machine X i5 simplified with the
minimized number of parts used. This in turn enables the
machine X to be manufactured light in weight and compact in
structure. In addition, since the drive chains 29a to 29d
are positioned downwardly of the associated drive wheels 2a
to 2d and are covered by the covers 12 and 14, and since the
lZ~19~48
- 30 -
trailing run l9b is covered by the covering 47, there is no
possibility that some of the tree branches cut from the tree
trunk may be jammed or entangled. Moreover, since each of
the drive wheels 2a to 2d is in the form of a rubber-tired
5 metal wheel as described with reference to Figs. 15 and 16,
not only are the drive wheels 2a to 2d durable, but also any
possible slippage of the drive wheels 2a to 2d relative to
the tree trunk can be minimized.
The feature that the chain chain saw 3 is
adjustable in its angle of inclination by adjusting the
position of the fixture 51 for the bearing boss 13 is
advantageous in that the position of each tree branch where
the cutting by the chain saw 3 should be effected can be
adjusted. In other words, it is possible to cut a tree
branch at a position spaced a certain distance from the tree
trunk during one helical turn of the machine and to cut the
same branch at a position close to the tree trunk during the
next succeeding helical turn of the machine. In this case,
upper and lower portions of the leA~ing run l9a of the saw
chain 19 are utilized at different time.
The use of the retractable idle roller i8
advantageous in -k i ng the machine to move downwards along
the tree trunk ~or the recovery of the machine. Because of
this, the engine need not be reversed, as is the case with
the prior art, when the machine is desired to be recovered.
Although this invention has fully been described
in connection with the preferred embodiment thereof with
~Z0~44~
- 31 -
reference to the accompanying drawings, various changes and
modifications are apparent to those skilled in the art. By
way of example, as shown in Fig. 32, an output shaft 28 of
the reduction gear unit 26 may extend downwardly from the
reduction gear unit 26 while the drive chain 29c for the
drive wheel 2c located above the output shaft 28 may be
drivingly coupled thereto. In addition, the auxiliary
framework the auxiliary unit may be of an integral
construction with the bearing sleeves and/or the spring
casings.
Furthermore, as shown in Figs. 33 and 34, instead
of the reel release mechanism operatively coupled to the
centrifugal clutch, it may comprise a cam member 93 adapted
to be driven by a motor g6 and supported so as to operate
the operating plate 68. In this case, the motor 96 may be
controlled by a wireless remote controller 95 capable of
transmitting a c ~n~ to a receiver 94 which i9
electrically connected to the motor 96.
Such changes and modifications are to be construed
as included within the scope of this invention as defined by
the appended claims, unless they depart therefrom.
