Note: Descriptions are shown in the official language in which they were submitted.
CA 02355057 2001-09-24
WO 00/3b250 PCTlCA99100019
SNOW GROO~ERS AND CONTRO~SYSTEM THEREFOR
Field of the invention
The invention relates to snow groomers and to implement controls for snow
groomers and for other utilitarian motorized vehicle.
Backg~cound of the invention
Snow groomers are tracked vehicles used for preparing snow surtaces such as
ski slopes , cross-country ski trails, snow mobile trails and the like to
obtain a
smooth compacted snow covered surface of a desired configuration to facilitate
the practice of winter sports and reduce the risks of accidents while
practicing
these winter spans. Snow groomers are normally equipped with a variety of
snow grooming and conditioning implements which are operated from the
operator's cabin enabling the operator to control these implements white the
snow groomer is moving.
Joysticks are commonly used to control work implements on snow groamers and
on a variety of utilitarian vehicles. The lateral motion and the fore and aft
motion
of the joystick normally control the hydraulic system of a single work
implement.
In some instances, the joystick will be adapted to control a second implement
by
rotating the joystick clockwise or counterclockwise while still controlling
the
primary implements.
Joysticks are also constructed with a base featuring a cordon joint or
universal
joint to provide motion of the stick in all directions and feature electric
position
sensors finked to the shaft of the joystick as is disclosed United States
Patent
No. 5,576,704 to Baker et al. The relative position of the joystick in
relation to
the position sensors is translated by a control means into motion of a
specific
CA 02355057 2001-09-24
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~16-01-2001 ~~ PCTlCA99/00019 DESCPAMD
i
work implement and in some instances, the joystick affords some degree of
control over the aaceteration and deceleration of the specific vrrork
implement.
Clnited Stales Patent No. 4,574,65~t to !_ennart et at. discloses a ooc>trol
sick for
a fighter aircraft that cantrois a piurafdy of functions. An array of selector
switches and buttons are disposed either on the handle or In close proximity
of
the handle enaixing the picot to control many functions without removing his
hand from the controt stick. The contra! stick has tvuo separate portions. The
lower portion only moves fore and aft clang a single axis and controls the
engine
14 Throttle. The upper po~an of the cantrot stick is swingabie along two axes
similar
to a cc~nventiona! joystick and its sole purpose i~s tn control the radar
orientation
and range. Buttons and switches on tfie control stick unit operate control
mstrurr:entalities and radar mode selection while the joystick maintains radar
control.
i5
U!~ Fatant application GS 2. 244 74?A discloses a joystick fQr contratling a
:,teaninc0 vehicle. The Toy licit :uses a first microswitch 170 and a second
microsu~;tcf ~ t 0~~, both canezecte~a to a co-~trot anodule i98 to control
varsous
cleaning irnpt<ements and operations. tn the presence of a plurality of
?0 independent wo~i~: implements requiring joystick contorts, a plurality of
joysticks
are usually installed, one for each impiement_ it is not uncommon to sea up to
fve joysticks in a single opsrato~s cabin_ This array of joystick controls is
cumbersome and less than efficient in a small operator's cabin.
25 Objects and statement of the invention
tt is thus an object of the invention to provide an improved snow grooming
vehicle.
ft is anofiher object of the invention to provide a multifunction joystick
control
;0 sy'~tem ecfaFted to seiectivety control a plurality of independsrit
functions.
It is another abjec: cf the invention to provide a rnultitunction joystick
control
AMENDED SHEET
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CA 02355057 2001-09-24
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16=01-2001 PCT/CA99/00019 DESCPAMD
system adapted to combine hydraulic oorrtrol for some implement fimc~or~s with
electrical control for other implement fiunctlons.
Yet another object of the invention is to prnvide improved Implements controls
fior utilitarian vehicles-
it is also an object of the invention to provide an improved snow grooming
vehicle adapted to selectively control a piuralit)r of Independent functions
using
a single mu~Ifunction joystick.
As embodied and broadty described herein, the invenfion provides a snow
grooming vehicle having a frame supported and propelled by ground engaging
tracks, an operator's cabin mounted to the frame, implement aoupiing means for
at least one snow working implement carried by the frame, and at least iwo
sets
t5 of implement actuators which are subject to operational control by the
operator
7om within the Qperator's cabin. Each set, of implement actuators being
contrafiabie by a joystick independently of the control of any other set of
irrrplement actuators_ The snow grooming vehiGe has an engine for driving the
ground engaging tracks, the joysfick has a hand grip portion positioned fior
convenient manipulation try the operator when sitting into the operator's
cabin
in a normal command position. Etec~trical transducer means acre operatively
associated with the joystiGt for generating an electrical signal
representative of
the position Qf the joystick. Manual oantroi switching means operable by the
operator from Its normal command position are provided for selecting a set of
irrrplement actuators of which the operator desires to change the condition by
means of #te joystick thereby adjusting the position or setting of an
implement
accordir~ to the position of thp joystick_ There is a oontr~ller having at
least two
inputs and one output and generating an output signal representative of the
position of the joystick for operatively controlling the set of impierner7t
actuators
selected by the operator. The manual control switching means arse coupled to
a first inp~.~t of said ~ntraile , the electrical signal produced by the
electrical
-;
AMENDED SHEET
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WO 00/36250 PCT/CA99f00019
transducer means are coupled to a second input of the controller, whereby
while the manual control switching means is actuated, the controller generates
an output signal representative of the position of the joystick which is used
to
operatively control a predetermined set of implement actuators: the joystick
being adapted to control at least one other set of implement actuators when
the
manual control switching means is not actuated.
Preferably, one snow grooming implement is a front snow blade and the other
set of implement actuators which are controlled by the joystick when the
manual
control switching means is not actuated consists of a first hydraulic cylinder
which sets the height of the front snow blade and a second hydraulic cylinder
which sets the tilt angle of the front snow blade.
Advantageously, the first and second hydraulic cylinders are controlled by a
set
of hydraulic control valves which are mechanically linked to, and controlled
by
the joystick and rendered inoperative whenever the manual control switching
means is actuated.
As embodied and broadly described the invention also provides a
snowgrooming vehicle having an internal combustion engine, a frame, an
operator's cabin supported by the frame, a set of ground engaging tracks, a
drive mechanism linking the engine to the ground engaging tracks enabling the
vehicle to move on snow, implement coupling means for at least one implement,
the implement being subject to functional control by the operator from within
the
operator's cabin, a multifunction joystick control system for selectively
controlling
an implement carried by the implement coupling means. The multifunction
joystick control system comprises a joystick having a hand grip portion
positioned for convenient manipulation by the operator when sitting into the
operator's cabin in a normal command position, manual control switching means
operable by the operator from the normal command position for selecting a
function of an implement that the operator desires to control by normal bi-
axial
4
r
CA 02355057 2001-09-24
WO 00135250 PCT/CA99/00019
manipulation of the joystick, a controller for generating an output signal
which is
used for effecting the operational control of the function of an implement
selected by the operator whenever the manual control switching means is
actuated. The multifunction joystick control system is adapted to also control
the
operation of at least one other function of an implement by normal bi-axial
manipulation of the joystick while the manual control switching means is not
actuated.
Preferably, the multifunction joystick control system further comprises a set
of
electrical transducers operatively associated with the joystick for generating
an
electrical signal representative ofthe position ofthe joystick, the electrical
signal
generated by the set of electrical transducers being coupled to a second input
of the controller.
Advantageously, the manual control switching means generates an electrical
signal representative of the selected function of an implement, and this
electrical
signal generated by the manual control switching means is coupled to a first
input of the controller.
The invention also provides a multifunction joystick control system for a snow
grooming vehicle which has a frame, ground engaging tracks, an operator's
cabin, an engine for driving the vehicle, implement coupling means for at
least
one snow grooming implement and at least two sets of implement actuators
separately controlled by the operator, each set of implement actuators being
controllable by a joystick. The multifunction joystick control system has a
joystick having a hand grip portion positioned for convenient manipulation by
the
operator when sitting into the operator's cabin in a normal command position,
a
set of electrical transducers operatively associated with the joystick for
generating an electrical signal representative of the position of the
joystick, a first
manual control switching means operable by the operator from the normal
5
CA 02355057 2001-09-24
WO OOI36250 PCT/CA99/00019
command position for selecting a first set of implement actuators that the
operator desires to operationally control, the first manual control switching
means generating an electrical signal representative ofthe first set of
implement
actuators, and a controller having at least two inputs and one output and
generating an output signal for effecting the operational control of the set
of
implement actuators selected by the operator. The electrical signal generated
by the first manual control switching means is coupled to a first input of the
controller. The electrical signal generated by the set of electrical
transducers is
coupled to a second input of the controller. The controller generates a first
output signal when the first manual control switching means is actuated, the
first
output signal being representative of the position of the joystick and being
used
to control the operation of the first set of implement actuators. The
multifunction
joystick control system is adapted to control the operation of at least one
other
set of implement actuators as a function of the position of the joystick when
the
first manual control switching means is not actuated.
Preferably, the other set of implement actuators consists of a set of
hydraulic
cylinders which require control by the operator for proper operation of the
utilitarian vehicle. The multifunction joystick control system also comprises
a
hydraulic circuit for operating the hydraulic cylinders, control valve means
operatively associated with the joystick for cantrolling hydraulic fluid
supply
through said hydraulic circuit to the hydraulic cylinders as a function of the
position of said joystick and disabling means for disabling the control valve
means when the first manual control switching means is actuated.
Advantageously, the manual control switching means comprises at least one
push button located on the hand grip portion of the joystick.
As embodied and broadly described, the invention also provides a multifunction
joystick control system for a utilitarian vehicle having at least one
implement and
at least two sets of implement actuators which are subject to operational
control
6
CA 02355057 2001-09-24
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tiJ '!~:J~J~1-'~E:S:t! 7
16-01-?001 PCT/CA99100019 D ESCPAMD
by the operator from within an operator's ratrin in the uxilltarian vehicle.
F~ set
of implement actuators is controllable by a joystick independently of the
oontroi
of any other set of implement actuators. The multifunction joystick corttro!
system features a joystick having a hand grip po~rban positioned far
convenient
manipulation by the operator when sitting into the operator's cabin in a
manna!
command position, a set of electrical transducers operatively associated with
the joystick for generating an electrical signal representative of the
position of
the joystick, a first manual control switching means operable by the operator
from the c~rmai command pust~on for selectir~ a fcrst set of Implement
actuators
IO that the operator desires to operationally control, the first manual
control
switching means generating an electrical signal representative of the first
set of
implement actuators, a controller having at least two Inputs and one output
and
generating an output signal for effecting the operational control of the set
of
implement actuators selected by the operator. The electrical signal generated
>.5 by the first manual control switching means is applied to a nrst input of
the
controller. The electrical signal generated by the set s~f electrical
trar~ducers
iaeing applied to a secar~d input of the controller. The contnaller generates
a first
output signal when the fist manual control switching means is actuated, the
fast
out~c.~t signal being representative of the position of said joystick and
being used
20 to con~ol the oper2tion of the first set of implement actuators. The
multifunction
joystick control system is adapted to control the operation of at Least one
other
set of implement actuators v~rhen the first manual control switching means is
not
actuated.
25 As embodied and broadly described, the invention also provides a
multifunction
joystick for controlling a plurality of independent operations of implements,
comprising: a ha:xfie mounted on a movable shank; a signal actuator positioned
adjacent to the shank and connected to a controller, and a hydraulic actuator
coupled to the shank and connected to a hydraulic system; wherein tha handle
;o is selectively movable to acf.~ate the hydraulic a~uator and to actuatE
tire signal
actuator to contn~l opecation of the implements based on a position of the
shank.
Other objects and feaiures of the invention will become apparent by reference
to the follov~hng description and tf~e drawings.
AMENDED SHEET
Printed:;-_'~-v ~-wv ~
3
CA 02355057 2001-09-24
WO OOI3G250 PCT/CA99/00019
B~i~f descri ttp 'on of tlhe drawinas
A detailed description of a preferred embodiment of the present invention is
provided herein below, by way of example only, with reference to the
accompanying drawings, in which:
Figure 1 is a perspective view illustrating a multifunction joystick according
to the
invention, installed in an aperator's cabin;
Figure 2 is a front elevational view of the multifunction joystick illustrated
in
figure 1;
Figure 3 is a rear elevationai view of the multifunction joystick illustrated
in
figure 1;
Figure 4 is a side elevational view illustrating a typical snow groomerwith a
front
snow blade and a rear snow grooming accessory;
Figure 5 is a top plan view illustrating the snow groomer shown in flg. 4;
Figure 6 is a perspective view illustrating a the multifunction joystick
according
to the invention with the handle portion removed;
Figure 7 is a top plan view of the multifunction joystick as shown in fig. 6;
Figure 8 is a side elevational view of the multifunction joystick as shown in
fig.
6and7.
Figure 9 is block diagram depicting the controller of the multifunction
joystick
according to the invention,
8
CA 02355057 2001-09-24
WO 00!36250 PCT/CA99/00019
In the drawings, preferred embodiments of the invention are illustrated by way
of examples. It is to be expressly understood that the description and
drawings
are only for the purpose of illustration and are an aid for understanding.
They are
not intended to be a definition of the limits of the invention.
Detailed descriution of deferred embodiments
With reference to Figure 1, 2 and 3, a novel multifunction joystick is
designated
generally by reference numeral 10. Joystick 10 has a handle portion 14 which
can be manipulated by the operator from its normal position. Joystick 10 is
adjustably mounted to a side arm 52 of the operator seat in a snow groomer
cabin and all work implements of the snow groomer are controlled and, in
accordance with the invention, actuated by the operator via the multifunction
joystick 10. Although the invention is described in relation with tracked
vehicles
used for grooming snow trails, ski slopes and the like, control system in
accordance with this invention may find application in any type of utilitarian
vehicles featuring work implements that require segregated joystick control.
Referring to Figures 4 and 5, a conventional snow groomer 60 is illustrated.
The
snow groomer 60 is constructed around a narrow frame 110 on which the
operator's cabin 66 is mounted. An internal combustion engine is positioned
in the mid-section of snow groomer 60 and a muffler 67 is provided to evacuate
the exhaust gas produced by the internal combustion engine. At the rear of
snow groomer 60 is a utility compartment 112 provided to carry tools and
equipment. Snow groomer 60 is supported and propelled by a pair of wide snow
engaging tracks 65 and their associated tandem wheels 69, single wheels 68
and suspension system (not shown) on frame 110 in accordance with
conventional practice.
Snow groomer 60 is shown with a front work implement 62 and rear work
9
CA 02355057 2001-09-24
WO OOI36Z50 PCT/CA99/00019
implement 64. Front work implement 62 consists of a large front snow blade 72
with adjustable wings 71 and 73. Front blade 72 is coupled to frame 110 by
means of a single-arm frame 70 on an attachment point 120 consisting of a ball-
joint which enables partial rotation of front blade 120 about a vertical axis,
a
transverse axis and a longitudinal axis. Front blade 72 may be raised or
lowered
by a hydraulic cylinder'T6 connected at one end to the upper part of the frame
110 of the snow groomer 60 and at the other end to the lower part of the front
blade 72. Bfade 72 rnay be pivoted about the snow groomer's longitudinal axis
so that one side of the blade 72 is higher than the other. This is
accomplished
by actuating a tilt hydraulic cylinder 77 connected between the frontal
extremity
of the single-arm frame 70 and an attachment point 122 of blade 72. Tift
hydraulic cylinder 77 imparts a rotary motion to the front blade 72 about a
longitudinal axis of the snow groomer 60. This adjustment of the front blade
72
is referred to, in the industry, as tilting the front blade 72.
20
The angle of the front blade 72 in relation to the longitudinal axis of the
snow
groomer 60 is also adjustable using a pair of angler hydraulic cylinders 78A
and
78B located on both sides of the single-arm frame 70 which imparts rotational
motion to the blade 72 around a vertical axis. The pitch angle of the blade 72
is adjustable by a pitch hydraulic cylinder 79 linking the upper part of the
frame
110 with the upper part of the blade T2. Finally, the angle of the blade wings
71
and 73 may be adjusted by left-wing hydraulic cylinder 81 and right-wing
hydraulic cylinder 83 which open or close the angle of the blade wings 71 and
73.
The rear work implement 64 is mounted to the snow groomer 60 by means of
a conventional double-arm frame 85 acting as a implement coupling means.
Rearwork implement 64 consists of a tiller 90 provided with a variety of
hydraulic
adjustments. A first hydraulic cylinder 86 serves to raise and lower the
double-
arm frame 85 thereby raising and lowering tiller 90 relative to the ground. A
second hydraulic cylinder 87, positioned diagonally between the two arms of
the
CA 02355057 2001-09-24
WO 00/36250 PCT/CA99100019
double-arm frame 85, is provided to laterally displace the tiller 90 in
relation to
the snow groomer 60. A third hydraulic cylinder 88 attached directly to the
tiller
90 on one side and to the frame 110 of the snow groomer 60 on the other side
provides depth control of the tiller 90. When actuated, the hydraulic cylinder
88
imparts a rotation of the tiller 90 about the axis defined by the two
attachment
points 91 of tiller 90 to the rear double-arm frame 85. This rotation of
tiller 90
either increases the depth of tilling of the snow or reduces it. Finally, a
pair of
hydraulic cylinders 89, positioned atop tiller 90, actuate the tiller rear
flap 94
which increases or decreases the volume of the snow chamber 95.
As noted above, the illustrated work implements are well known in the art and
can be found in commercially available snow groomers. Other work implements
are also available, such as front snow blowers or compactors. These work
implements are normally controlled bythe same hydraulic system using separate
manual controls, one far each implement. Most of these work implements
require joystick control in that they cannot be fully controlled merely with a
single
direction lever or control switch. In other words, they are controllable as a
function of the bi-axial position or motion of a joystick.
An improved snow groomer, in accordance with this invention uses instead a
central system which has a multifunction joystick 10 for all implements. As
shown in figs. 1, 2, and 3, joystick 10 is swingable relative to the base 12
about
mutually perpendicular axes that intersect near the base 12. The multifunction
joystick 10 is, in this case, swingable about a fore-and-aft extending axis
and a
laterally extending axis. The joystick 10 may be configured for right hand or
left
hand actuation depending on where it will be located relative to the operator.
In
this example, a right hand multifunction joystick is illustrated.
The joystick 10 actuates, as a primary function, a conventional four-way
hydraulic valve which cantrols the flow of hydraulic fluid to a set of
hydraulic
11
CA 02355057 2001-09-24
WO 00/36250 PCTICA99/00019
cylinders thereby controlling the actions of these implement actuators. In
addition to joystick 10, the control system uses one or mare push buttons or
other type of manual control switching means to select a given function. In
the
illustrated embodiment, seven push buttons are shown numbered 21 to 27 which
are mounted to the upper part of joystick 10. Out of these seven push buttons,
four are used to select a function which requires inputs from the movements of
joystick 10. The other three buttons select functions that do not require
input
from joystick 10. Four buttons numbered 21, 22, 23, and 24, are located on the
portion of joystick 10 facing the operator {Fig. 2) and are positioned to be
easily
reachable by the thumb of the right hand of the operator; and three buttons,
numbered 25, 26, and 27, are positioned on the portion of the multifunction
joystick 10 facing away from the operator (Fig. 3). Buttons 24 and 25 are
preferably actuated by the forefingers while button 27 may be actuated by
either
the forefingers or the thumb. The multifunction joystick 10 also features a
knob
28 provided for setting the engine power output which overrides the gas pedal
or the directional levers of the snow groomer 60. Rotating knob 28
counterclockwise or upwards with the right hand thumb increases the engine
power output while rotating it clockwise or downwards decreases engine power
output.
By default, that is when none of the four buttons requiring inputs from the
movements of joystick 10 are actuated, joystick 10 controls the movements of
front blade 72. Pushing forward on joystick 10 will actuate hydraulic cylinder
76
and lower front blade 72 while pulling on joystick 10 backward will actuate
hydraulic cylinder 76 in the opposite direction and raise front blade 72.
Moving
joystick 10 laterally to the right or to the left actuates tilt hydraulic
cylinder 77
thereby tilting front blade 72 by raising or lowering the left side of blade
72
which rotates about its attachment point 120 to the single-arm frame 70.
Needless to say, moving joystick 10 to the left side, lowers the left end of
blade
72, and vice versa.
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WO 00/36250 PCT/CA99/00019
Push button 24 is dedicated to blade angle adjustment and pitch angle
adjustment. Pressing button 24 and keeping it pressed disables the default
function of the multifunction joystick 10, namely the raising and lowering and
the
tilting of the front blade 72 by actuating an electro-mechanical valve which
cuts
off the supply of hydraulic fluid to four-way hydraulic valve of joystick 10.
With
button 24 pressed, the movements of joystick 10 wilt act upon a pair of angler
hydraulic cylinders 78A and 78B and to pitch hydraulic cylinder 79. Electrical
transducers located at the base 12 of joystick 10 send signals representative
of
the position of joystick 14 to controller 100 (Fig. 9) which send a signal
representative of the bi-axial position of joystick 10 to an electro-
mechanical
four-way hydraulic valve which controls the supply of hydraulic fluid to
hydraulic
cylinders 78A, 78B and 79. This transfer of function of the multifunction
joystick
10 will hereafter be described in greater detail with reference to Figures 6
to 9.
A lateral motion of joystick 10 to the right or to the left, acts upon
hydraulic
cylinders 78A and 78B to adjust the angle of front blade 72 in relation to the
longitudinal axis of the snow groorner 60. The pair of hydraulic cylinders 78A
and 78B are part of the same hydraulic circuit and work in tandem. When
cylinder 78A extends, cytinder 78B retracts, thereby creating a rotational
displacement of front blade 72 which changes its angle in relation to the
longitudinal axis of the snow groomer 60. Hence when button 24 is maintained
actuated, a forward or backward motion of the multifunction joystick 10
actuates
pitch hydraulic cylinder 79 which controls the pitch angle of front blade 72.
A
forward motion of the multifunction joystick 10 extends pitch hydraulic
cylinder
79 and increases the pitch angle of front blade 72 while a rearward motion of
the
multifunction joystick 10 retracts pitch hydraulic cylinder 79 and decreases
the
pitch angle of front blade 72. When button 24 is released, the default mode of
the control system is resumed and joystick 10 automatically provides control
of
the height and tilt angle of front blade 72.
Pressing button 27 and keeping it pressed disables the default mode of the
multifunction joystick 10 as previously described. With button 27 pressed, the
13
CA 02355057 2001-09-24
WO 00136250 PCT/CA99/00019
movements of joystick 10 serve to the adjustment of the two blade wings 71 and
73. A lateral motion of joystick 10 either retracts or extends hydraulic
cylinder
83 thereby opening or closing the right blade wing 73. A fore-and-aft motion
of
joystick 10 either retracts or extends hydraulic cylinder 81 thereby opening
or
closing the left blade wing 71. Releasing button 27 reinstates the default
mode
of the control system.
The default mode of the control system and related joystick 10 and the modes
associated with buttons 24 and 27 enable the operator to control all the
hydraulic
cylinders necessary to manipulate and adjust the front blade 72.
In accordance with the present invention, the same control system and its
multifunction joystick 10 are used to also control the rear work implements
64.
Pressing button 23 and maintaining it pressed, disables the default mode of
multifunction joystick 10 and transfers the joystick controls to hydraulic
cylinder
88 for the fore-and-aft motion of joystick 10 and to hydraulic cylinders 89
forthe
lateral motion of joystick 1D. A forward motion of joystick 10 retracts the
hydraulic cylinder 88 thereby increasing the depth of tilling of tiller 90. A
rearward motion of joystick 10 extends the hydraulic cylinder 88 thereby
decreasing the depth of tilling. A lateral motion of joystick 10 extends or
retracts
the two hydraulic cylinders 89 positioned atop tiller 90 thereby actuating the
tiller
rear flap 94 upward or downward to adjust the snow chamber 95 by increasing
or decreasing its volume.
Pressing button 22 and maintaining it pressed, disables the default mode of
joystick 10 and transfers the joystick controls to hydraulic cylinder 86 for
fore-
and-aft movement of joystick 10 and to the diagonally positioned hydraulic
cylinder 87 for the lateral movement of joystick 10. Therefore, in this
condition,
a lateral movement of joystick 10 actuates hydraulic cylinder 87 and displaces
tiller 90 towards the right: or the left according to the motion of joystick
10. A
fore-and-aft movement of joystick 10 raises or lowers tiller 90 and the
rotation
14
CA 02355057 2001-09-24
WO OOI36250 PCTICA99/00019
of tiller 90 is automatically stopped. If tiller 90 is not in the central
position,
when the raising command is given, tiller 90 will be automatically returned to
the
central position before it is raised.
By pressing button 26, tiller 90 is lowered onto the snow by its own weight by
releasing the hydraulic pressure of hydraulic cylinder 86 and tiller 90
assumes
a vertical floating mode which simply means that it is resting on the snow and
will
follow the vertical contours of the terrain. Tiller 90 starts rotating as it
reaches
the snow. Button 26 does not require to remain pressed and is not associated
with any movements of joystick 10. The vertical floating mode will remain
until
button 26 is pressed again.
As part of the floating mode of tiller 90 previously mentioned, button 21 is
provided to control the pressure of tiller 90 on the snow. Button 21 is
coupled
with an "up-down" selector switch on the dashboard of the snow grooming
vehicle and to hydraulic cylinder 86. If the operator wishes to increase the
pressure exerted by tiller 90 on the snow surface, he verifies that the "up-
down"
selector switch is at the "down" position, and presses 'button 21 until the
pressure has built up sufficiently. Maintaining button 21 pressed builds up
pressure in the hydraulic cylinder 86 to pull on tiller 90. In order to
decrease the
pressure exerted by tiller 90 on the snow surface, the "up-down" selector
switch
must be at the "up" position and then button 21 can be pressed to build
pressure
in hydraulic cylinder 86 in the opposite direction to push on tiller 90
thereby
decreasing the pressure exerted by tiller 90 on the snow surface. Button 21
does not disable the default mode of multifunction joystick 10.
A further floating mode of tiller 90 is available. Button 25 is provided to
render
tiller 90 laterally floating which means that tiller 90 is free to move
sideways and
follow the various contours of the terrain. Button 25 in effect opens the
hydraulic
circuit of hydraulic cylinder 87 which enables the double-arm frame 85 to
freely
move laterally. This function of button 25 will remain uon" until a
contradictory
CA 02355057 2001-09-24
WO 00136250 PCTICA99l00019
command is given. A lateral displacement command of tiller 90 or a raising
command of tiller 90 with button 23 will disable the function of button 25.
Button
25 does not disable the default mode of joystick 10.
Multifunction joystick 10 has therefore a default function which consist of
raising
and lowering front blade 7 2 and tilting it. Other functions previously
described
and associated with motion of multifunction joystick 10 could become the
default
function as may be required for proper functioning of snow groomer 60
Referring now to figs. 6, 7, and 8 which show joystick 10 with its handle
removed
from the shank 36, joystick 10 comprises an annular base 30 adjustably
mounted to a fork-like support member 50. Joystick 10 comprises an hydraulic
section 32 and an electrical section 34. The hydraulic section 32 comprises a
standard four-way hydraulic valve (not shown) to which is mounted the shank
36. The four-way hydraulic valve is actuated when shank 36 is moved from its
central neutral position and hydraulic fluid is directed in four possible
directions.
Hydraulic fluid enters the four-way hydraulic valve through an supply line 38
and
exits the four-way hydraulic valve through at least one of four hydraulic
lines 37
or through a drain line 39. When shank 36 remains in its neutral position,
hydraulic fluid circulates from the supply line 38 to the drain line 39. If
the shank
3fi is moved in any direction, the four way hydraulic valve directs hydraulic
fluid
towards an hydraulic cylinder either on the piston side to extend the
hydraulic
cylinder or on the shaft side to retract the hydraulic cylinder depending on
the
movement of the shank 36. In this particular embodiment of the invention, the
hydraulic section of multifunction joystick 10 is the default function
referred to
earlier.
the electrical section 34 is mounted above the annular base 30 and comprises,
in this example, four electrical transducers 41, 42, 43, and 44 positioned
radialfy
around shank 36 at equal angular spacing from each other. Shank 36 features
a circular conical portion 40 provided to actuate the electrical transducers
41, 42,
16
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_~..._.~...~,_.~",."".........., ~ww~........ .._~,-,...-.,.."..~.-
CA 02355057 2001-09-24
WO 00/36250 PCT/CA99/00019
43, and 44 as soon as shank 36 is moved from its central neutral position. A
series of electrical wires 46 link each push buttons 21, 22, 23, 24, 25, 26,
and
27 to the controller 100 (shown schematically in Fig. 9) so that when one of
the
push buttons is actuated, the electrical signal produces by this push button
is
receives as an input by the controller 100.
Electro-mechanical four-way hydraulic valves are used to control the various
sets of implement actuators of the front work implement 62 or of the rear work
implement 64 of the snow grvomer. Controller 100 generates an output signal
representative of the position of the multifunction joystick 10 which is sent
to a
speck electro-mechanical four-way hydraulic valve selected by one of the push
buttons 22, 23, 24 or 27, which then directs the flow of hydraulic fluid to
the
specific set of hydraulic cylinders according to this output signal.
When any of the buttons 22, 23, 24 or 27 is pressed, the hydraulic fluid
supply
to supply line 38 is cut off by an electro-mechanical valve 105 (shown in
Fig.9)
located upstream from multifunction joystick 10 thereby disabling the four-way
hydraulic valve located in section 32 of multifunction joystick 10. When any
of
the buttons 22, 23, 24 or 27 is pressed, the electric signal produced by the
actuation of any of the electrical transducers 41, 42, 43, or 44, is sent to
the
specific electro-mechanical four-way hydraulic valve associated with the
button
being pressed. Electrical transducers 41 and 43 will translate fore-and-aft
motions of multifunction joystick 10, electrical transducers 42 and 44 will
translate lateral displacement of multifunction joystick 10.
Buttons 21, 25, and 26 are more directly linked to the various electro-
mechanical
hydraulic valve since the function they perform is not dependant on the
electrical
transducers 41, 42, 43, and 44. They perform on-off functions of a rear
hydraulic circuits and do not disable the default function of the
multifunction
joystick 10.
17
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WO 00/36250 PCT/CA99/04019
Figure 9 represents a block diagram of a controller 100 adapted to receive
signals
generated by the electric transducers 41, 42, 43 and 44 and by buttons 22, 23,
24
and 27, and in response thereto generate an output signal which will actuate
the
various electro-mechanical valves controlling hydraulic cylinders 78 and 79,
81 and
83, 88 and 89, 86 and 87, and 105. As soon as one of the buttons 22, 23, 24,
or
27 is actuated an output signal is sent to electro-mechanical valve 105 to
disable
the default mode of the multifunction joystick 10. Pressing one of the buttons
22,
23, 24 and 27 also selects one of the electro-mechanical valve controlling the
hydraulic cylinders 78 and 79, 81 and 83, 88 and 89, 86 and 87. Controller 100
applies an output signal to the selected electro-mechanical valve which is
representative of the electrical signal received from the electrical
transducers 41,
42, 43, 44. For example, when push button 22 is pressed, an input signal 220
is
sent to controller 100 which generates an output signal 510 to electro-
mechanical
valve 105 to disable the default mode. Input signal 220 is further interpreted
by
controller 100 to generate an output signal 504 representative of any input
signals
410, 420, 430, and 440 or combinations thereof received from electric
transducers
41, 42, 43 and 44 and to apply output signal 504 to the electro-mechanical
valve
controlling hydraulic cylinders 8fi and 87. Controller 100 generates an output
signal 510 as soon as any one of push buttons 22, 23, 24, and 27 is actuated.
Controller 100 generates an output signal 503 to the electro-mechanical valve
controlling the hydraulic cylinders 88 and 89 from an input signal 230
generated
when button 23 is actuated. An output signal 501 to the electro-mechanical
valve
controlling the hydraulic cylinders 78 and 79 is generated by controller 100
from
input signal 240 generated when button 24 is actuated. Controller 100
generates
an output signal 502 to the electro-mechanical valve controlling the hydraulic
cylinders 81 and 83 from input signal 270 generated when button 27 is
actuated.
Controller 100 may made of a series of standard relays which are energized
upon
pressing any one of buttons 22, 23, 24, and 27. These relays respond to the
condition of electrical transducers 41, 42, 43, and 44 and apply an electrical
signal
which actuates the various efectro-mechanical four-way hydraulic valves.
18
CA 02355057 2001-09-24
WO OOI36250 PCT/CA99/00019
Controller 100 could also be easily achieved using a suitable micro processor
relaying the various commands of multifunction joystick 10 to the various
electro-
mechanical four-way hydraulic valves.
In a particular embodiment of the invention, standard electrical transducers
are use
for translating joystick movement into signals to the electro-mechanical
valves but
other means are just as suitable. Position sensors, proximity sensors, hall-
effect
sensors, magnetic switches and so on may be used to perform the same tasks.
Also, the electrical transducers are actuated by the circular conical portion
40 of
shank 36. They could easily be positioned underneath a surtace projecting from
the shank 36 and actuated by this surface when the multifunction joystick 10
is
moved in any direction. Other obvious means to produce a usable signal are
possible without departing from the spirit of the invention.
The above description of preferred embodiments should not be interpreted in a
limiting manner since other variations, modifications and refinements are
possible
within the spirit and scope of the present invention. The scope of the
invention is
defined in the appended claims and their equivalents.
19
