Note: Descriptions are shown in the official language in which they were submitted.
CA 02280540 1999-08-19
ALL TERRAIN VEHICLE
Field of the Invention
This invention relates to the field of all terrain vehicles, and in particular
to
vehicles adaptable to rolling translation over land, climbing translation over
obstacles, floating
translation over water, and sliding translation over snow.
Background of the Invention
It is well understood that negotiating difficult terrain often requires
specialized
vehicles, for example, it is known to provide a hovercraft for the transition
from land to water, and
vice versa. However, such transportation is not well adapted for negotiating
obstacles and requires
a large amount of power and is typically of high maintenance. Four wheel drive
vehicles are well
understood and operate over somewhat rough terrain on land but are not adapted
for use on water
or in deep snow. Boats and other water craft, whether propeller driven or
driven by jet drives, are
of course not well adapted for use on land. Other specialized vehicles have
also been proposed
for use in rough or hostile terrain, for example, that disclosed by Fletcher
in United States patent
No. 3,730,287 issued May 1, 1973 for a Vehicle for Use in Planetary
Exploration.
The planetary exploration vehicle of Fletcher has a frame on which are mounted
independently operable propulsion units, each unit including an extending leg
coupled to the frame
for rotation about a transverse axis. The extended leg is supported by a
steerable pedestal having
the attributes of a wheel and an endless track. The extended legs may be
rotated about the
2 5 transverse axis to overcome obstacles. The pedestal track may be rotated
to translate the frame
in the manner of wheeled or tracked translation. What is neither taught nor
suggested, and which,
without intending to be limiting, is one object of the present invention to
provide, is the use of
floatation wheels on the end of selectively rotatable legs for high speed
overground rolling
1
CA 02280540 1999-08-19
translation combined with selectively removable floatation units for over
water translation and
selectively removable traction drive units and skis for translation over snow.
What is also neither
taught nor suggested is the use of a center articulated frame for increased
manoeuvrability in
combination with the selectively rotatable legs.
Summary of the Invention
In summary, the all terrain vehicle of the present invention includes a
platform for
carrying an operator, the platform having a front frame and a rear frame. The
front frame has a
first end and an opposite second end. The first end corresponds to a front end
of the platform. The
rear frame also has a first end and an opposite second end. The second end of
the front frame is
pivotally mounted to the first end of the rear frame. This allows pivoting of
the front frame
relative to the rear frame about a vertical frame articulation axis. An
articulation drive is mounted
to the platform for selective actuating of an articulation linkage mounted
between the front and
rear frames so as to selectively pivot the front frame relative to the rear
frame about the
articulation axis.
The front frame has first and second opposite sides. The rear frame also has
first
and second opposite sides. A first front leg is rotatably mounted to the first
side of the front frame.
2 0 A second front leg is rotatably mounted to the second side of the front
frame. A first rear leg is
rotatably mounted to the first side of the rear frame. A second rear leg is
rotatably mounted to the
second side of the rear frame. The front and rear legs are elongate. Each leg
has a hub end and
an opposite wheel end. Each leg is rotatable about its hub end substantially
vertical planes
corresponding to each of the legs. The front and rear legs are selectively
independently rotatable
2 5 relative to each other and relative to the front and rear frames by
selective actuation of
corresponding independent leg rotation drives. The leg rotation drives are
mounted to the platform
and engage the hub ends of the legs.
2
CA 02280540 1999-08-19
First and second front wheels are rotatably mounted to corresponding wheel
ends
of the first and second front legs. The front wheels rotate in corresponding
second planes which
are generally parallel to the substantially vertical planes in which the front
legs rotate.
First and second rear wheels are rotatably mounted to corresponding wheel ends
of the first and second rear legs. The front wheels rotate in corresponding
third planes which are
generally parallel to the substantially vertical planes in which the front
legs rotate. The front and
rear wheels are floatation wheels.
At least one wheel drive linkage is mounted to at least one leg of the front
and rear
legs. Each wheel drive linkage is mounted in driving engagement with a
corresponding wheel.
A wheel drive is mounted to the platform for selectively actuating each wheel
drive linkage so
as to selectively drive rotation of the corresponding wheel about a
corresponding wheel end.
Advantageously, the frame articulation axis is generally centrally disposed on
the
platform.
Further advantageously, the articulation linkage is a reduction gear linkage
mounted to the front and rear frames. The articulation drive actuating the
articulation linkage may
2 0 be a double acting motor. Actuation of the motor may be by a switch or the
like biased by turning
of a steering column mounted to the platform. Biasing of the switch causes
either rotation of the
reduction gears in a first rotational direction so as to articulate the front
frame relative to the rear
frame in a first direction, or causes rotation of the reduction gears in a
second rotational direction,
opposite to the first rotational direction, so as to rotate the front frame in
a corresponding second
2 5 direction relative to the rear frame. The double acting motor may be an
electric motor. Thus,
turning the steering column biases the electric motor by toggling a switch
controlling the direction
of rotational drive of the electric motor. In one embodiment, not intended to
be limiting, the
double acting motor is mounted on the front frame along with the steering
column and a seat for
3
CA 02280540 1999-08-19
the operator. The seat may be mounted on the front frame generally adjacent
the second end of
the front frame, advantageously on a seat pillar co-axial with the
articulation axis.
In one aspect of the present invention, the leg rotation drive are pinion
gears
mounted on stub drive shafts. The stub drive shafts are rotatably mounted to
the platform. The
pinion gears mate with corresponding ring gears mounted on the hub ends of the
legs. In the
preferred embodiment, the ring gears are mounted within a hub housing on the
hub ends, and the
pinion gears extend into mating engagement within the ring gears so as to
engage ring gear teeth
spaced around an internal circumference of the ring gears. The hub ends are
rotatably mounted
on stub axles which extend through, co-axial with, the ring gears.
In one embodiment of the present invention which provides for resilient
suspension of the vehicle as it travels, the ring gears are rotatably mounted
within the hub
housings. The ring gears are free to rotate within a small range of radial
travel relative to the hub
housings in resiliently biased suspension about a neutral position suspended
between opposed
resilient biasing means mounted on the hub housings. The resilient biasing
means may be a pair
of oppositely disposed springs, the springs mounted at their opposite ends to
the hub housings.
The springs sandwich a flange between their inner adjacent ends. The flange is
rigidly mounted
to, and protrudes from, the ring gears so as to extend rigidly from the ring
gears into the space
2 0 between the inner adjacent ends of the springs. The flange mass protrude
from the ring gears
through corresponding slots in the hub housings.
In a further aspect of the invention, the wheel drive linkage is a second
drive shaft
rotatably mounted to the platform. Alternatively wheel drive linkages are
provided to two or more
2 5 of the wheels. The second drive shaft actuates a chain drive rotatably
mounted along the length
of the corresponding leg. The chain drive actuates rotation of the
corresponding wheel about its
wheel stub axle. Advantageously a wheel drive linkage is provided for both the
first and second
rear legs, and the wheel drive is a motor mounted to the rear frame.
4
CA 02280540 1999-08-19
In an embodiment of the present invention capable of over-water travel, the
front
and rear frames are adapted for mounting corresponding front and rear
floatation pods to the
undersides of the frames. Mounting means are mounted to the undersides of the
front and rear
frames so as to releasably mate the floatation pods thereon. When the front
and rear legs are
selectively rotated so as to position the front and rear wheels generally
level with a floatation level
of the floatation pods when mounted to the undersides of the front and rear
frames, the wheels
assist the all terrain vehicle to float stably in the water.
To assist in over-water travel, a propeller drive may be mounted to the
platform.
A propeller drive linkage is mounted at one end to the propeller drive, and at
its opposite end to
a rotatably mounted propeller. The propeller drive, which may be a power take-
off from the main
motor on the rear frame, actuates the propeller drive linkage which in turn
rotates the propeller.
The propeller may be mounted at one end of an actuable arm, the actual arm
rotatably mounted
at its other end to the platform. Thus the end of the actuable arm on which
the propeller is
mounted may be raised and lowered between an elevated position, when use of
the propeller is not
required, and a lowered position so as to engage the propeller with the water.
Advantageously,
the propeller drive linkage is mounted along the actuable arm.
2 0 In an embodiment of the present invention capable of travel over snow, the
front
and rear legs can be selectively rotated so as to mount a pair of endless
tracks thereon. To install
the tracks, the front wheels are rotated into a position disposed rearwardly
towards the rear wheels,
and the rear wheels are rotated into a position disposed below the rear frame.
A first endless track
is positioned over the first front wheel and the first rear wheel. A second
endless track is
2 5 positioned over the second front wheel and the second rear wheel. Once so
positioned, the front
legs are selectively rotated so as to tighten the first and second endless
tracks over their respective
front and rear wheels.
5
CA 02280540 1999-08-19
In this embodiment, a steering ski is releasably mountable to a lower end of
the
steering column so as to protrude from below said front frame. An articulation
drive disabling
means is provided. It is selectively actuable so that the operator may disable
the articulation drive
and thereby rigidly position the front frame relative to the rear frame. Once
the articulation drive
is disabled, the steering column may be turned to steer the steering ski.
In a further aspect of the present invention, the steering column has a
releasably
lockable hinge mounted along its length. The hinge is selectively releasable
so that the top of the
steering column and the steering wheel atop the steering column may be pivoted
into a lowered
storage position. In addition, the seat is removable for storage or
transportation. With the steering
column folded down and the seat removed, the vehicle has a vertical height no
higher than the
height of the tire.
Brief Description of the Drawings
Figure 1 is, in perspective partially cut-away view, the all terrain vehicle
of the
present invention.
Figure 2 is, in plan view, the all terrain vehicle of the present invention in
a left
2 0 hand articulated turn.
Figure 3 is, in side elevation view, the all terrain vehicle of the present
invention
approaching an obstacle to be cleared.
2 5 Figure 4 is, in exploded perspective view, the wheel drive and articulated
leg of the
all terrain vehicle of the present invention.
6
CA 02280540 1999-08-19
Figure 5 is a partially exploded perspective view of an alternative embodiment
of
the wheel drive and articulated leg of the all terrain vehicle of the present
invention.
Figure Sa is a further partially exploded perspective view of the wheel drive
and
articulated leg of Figure 5.
Figure Sb is, in partially exploded perspective view, the articulated leg of
the
forward legs of the all terrain vehicle of the present invention.
Figure 6 is, in enlarged rear perspective view, the wheel drive and leg
articulating
drive mechanism of the all terrain vehicle of the present invention.
Figure 7 is, in partially cut-away plan view, the steering articulation
mechanism
of the all terrain vehicle of the present invention.
Figure 7a is, in partially cut-away enlarged view, the lower end of the
steering
column.
Figure 8 is, in side elevation view, the all terrain vehicle of the present
invention
2 0 in its storage and transportation position having completed self loading
onto a pick-up truck bed.
Figure 9 is, in side elevation view, the steering wheel and steering column
showing, in dotted outline, the steering wheel in a folded down position for
storage.
2 5 Figure 10 is, in front elevation view, the all terrain vehicle of the
present invention
with its port wheels elevated and its starboard wheels generally vertically
disposed beneath the
vehicle frame for side hill translation.
7
CA 02280540 1999-08-19
Figure 11 is, in side elevation view, the all terrain vehicle of the present
invention
with its detachable flotation pods releasably mounted to the underside of the
frame.
Figure 12 is, in rear perspective view, the all terrain vehicle of Figure 11
with its
propeller deployed.
Figures 13 is, in left side elevation view, the all terrain vehicle of the
present
invention in its snow terrain mode.
Figure 14 is, in partially exploded side elevation view, the ski attachment
for
mounting to the all terrain vehicle of Figure 13.
Detailed Description of Preferred Embodiments
As illustrated in Figures 1-3, the all terrain vehicle of the present
invention
includes a forward supporting frame 10 pivotally mounted to an aft supporting
frame 12 by means
of a pin coupling 11. The two frames 10 and 12 overlap across a generally
centrally located
vertical axis of articulated rotation 14 of forward supporting frame 10
relative to aft supporting
frame 12. Pin coupling 11 lies on axis 14. Thus, the forward and aft
supporting frames form a
2 0 complete vehicle frame. The vehicle frame is articulated in the middle
about axis 14 for steering
of forward floatation wheels 16a and 16b relative to aft floatation wheels 18a
and 18b, that is, by
rotation of forward frame 10 in direction A relative to aft frame 12.
The forward and aft floatation wheels are each mounted on a corresponding leg,
2 5 for ease of reference numbered 20a and 20b to correspond to forward
floatation wheels 16a and
16b, and 22a and 22b to correspond to aft floatation wheels 18a and 18b.
Forward supporting
frame 10 has mounted thereon steering wheel column and steering wheel 24 and
26 respectively.
Driving controls 28 and mounted on forward frame 10, such as for example, and
for illustrative
8
CA 02280540 1999-08-19
purposes only, may be found in conventional vehicles, in particular brake and
throttle pedals.
Driving controls 28 are cooperatively connected via cable linkages or other
means known in the
art to at least one main propulsive unit or prime mover 30 which may be one or
more gasoline
powered reciprocating engines or the like known in the art mounted on to aft
supporting frame 12.
An operator's seat 32 may be mounted to forward supporting frame 10,
conveniently so as to
position an operator in proximity to vertical articulating axis 14.
Legs 20a and 20b are pivotally mounted on opposite lateral sides of forward
supporting frame 10. Legs 22a and 22b are pivotally mounted on opposite
lateral sides of aft
supporting frame 12. Each leg is selectively rotatable about a corresponding
stub shaft, the
laterally outermost ends of which numbered for ease of reference 34a, 34b, and
36a and 36b
respectively. Each of the aft legs contain the same structure, shown
representatively with respect
to leg 22a in Figure 4. Leg 22b is a mirror image of leg 22a. The laterally
outermost ends of the
stub shafts are contained within corresponding bearing housings 37.
Advantageously, in one
preferred embodiment as seen in Figure 4, the end of the stub shaft contained
within bearing
housing 37 is a stepped shaft rotatably encased between laterally opposed sets
of roller bearings
39 laterally spaced apart sufficiently so that a radially enlarged stepped
portion (36a' in Figure 4)
of the shaft is held between the laterally spaced apart sets of roller
bearings 39 within bearing
housing 37.
The legs may thus be rotated about transverse axis of rotation 38
corresponding to
forward legs 20a and 20b, and transverse axis of rotation 40 corresponding to
aft legs 22a and 22b.
The forward legs may be rotated about transverse axis of rotation 38 in
direction B so as to rotate
the wheels from their storage positions (shown in dotted outline) to a lowered
drive position.
2 5 Similarly, the aft legs may be rotated in direction C about transverse
axis of rotation 40.
As seen in Figures 4, 5 and Sa, rotation of the legs in direction B or in
direction C
is selectively actuated by means of a pinion gear 42 in each leg mounted on a
corresponding
9
CA 02280540 1999-08-19
pinion gear shaft 44. Pinion gear 42 engages ring gear 46 mounted to the
laterally inner side of
the corresponding leg. As better described below, ring gear 46 is fitted into
the inner side of
housing 106 on a corresponding leg and held in place by a retainer ring 108.
Ring gear 46 can
rotate relative to housing 106 approximately 1 1 /2 inches either side of a
resiliently centered
position against the return biasing force of coil springs 102 to give the
wheels a corresponding six
to eight inches resilient travel either way for a spring cushion effect.
Pinion gear 42 engages ring
gear 46 in toothed engagement so that rotation of pinion gear shaft 44 rotates
the corresponding
leg about its corresponding transverse axis of rotation 38 or 40. Pinion gear
shafts 44 may be
driven by corresponding electric motors such as 12 volt WarnerTM winch motors
50, one motor
for each leg, such as seen in Figure 6. Motors 50 rotate gear shafts 44 via
drive chains SOa and
gears SOb.
Aft floatation wheels 18a and 18b may be selectively driven by means of drive
sprocket 52 rigidly mounted to corresponding stub axle drive shaft 36a or 36b
driving drive chain
54. Prime mover or propulsive unit 30 drives drive shaft 48. Drive shaft 48
rotates drive chain
48a, which rotates the stub axle drive shaft 36a or 36b. Drive chain 54
engages, at the radially
distal ends of the legs illustrated by way of example as leg 22a, wheel drive
sprocket 56 rigidly
mounted to corresponding stub axle 58. Corresponding floatation wheels 18a or
18b are rigidly
mounted on the opposite end of stub axle 58 so that rotation of wheel drive
sprocket 56 by drive
2 0 chain 54 rotates stub axle 58 and the corresponding floatation wheel to
thereby provide rolling
traction for rolling translation of the vehicle. Chain 54 may be provided with
spring biased chain
tensioner arm 54a (seen in Figures 5 and Sa). It is understood that it is
within the scope of the
invention that forward wheels 16 also provide drive traction in a fashion
similar to the aft wheels.
However, in the embodiment illustrated, forward wheels 16 are not drive wheels
and thus, as in
2 5 Figure Sb, leg 20a does not contain drive sprockets 52 or 56 and drive
chain 54. Leg 20b is a
mirror image.
CA 02280540 1999-08-19
Forward legs 20 and aft legs 22 may be provided with suspension 100.
Suspension
springs 102 are mounted in opposed orientation on either side of a spring
mount 104 rigidly
mounted to ring gear 46. With ring gear 46 snugly journalled within ring gear
housing 106 and
rotatably mounted therein by means of retainer ring 108 mounted to ring gear
housing 106.
Retainer ring 108 may be either a machine fit as seen in Figures 5 and Sa, or
may be mounted
mounted by means of flanges 108a cooperating with bolt holes 106 a on housing
106.
Spring mount 104 is slidably mounted within slot 110. With spring mount 104
slidably mounted within slot 110 in ring gear housing 106. The distal ends of
springs 102 engage
stops 112 rigidly mounted to ring gear 106. Assembly of ring gear 46 into ring
gear housing 106
is facilitated by aperture 114 in slot 110. With ring gear 46 rotatably
mounted within ring gear
housing 106 so that spring mount 104 is free to slide within slot 110,
relative rotational movement
of leg 22 (leg 22a being illustrated) about stub shaft 36 (stub shaft 36a
being illustrated) relative
to ring gear 46, causes compression of one of the pair of springs 102 against
the corresponding
stop 112. Thus small relative movement is resiliently provided for as spring
mount 104 slides
within slot 110.
Steering of the vehicle, as described above, is accomplished by articulating
front
frame 10 relative to aft frame 12 about axis 14. As seen in Figures 7, 7a and
8, this may be
2 0 accomplished by providing a separate winch 50' articulating, through
reduction gearing, the
selective rotation of frame 10 about pin coupling 11. Winch 50' is a two-way
winch which, in one
embodiment, is actuated by rotation of steering column 24. Steering wheel 26
is mounted rigidly
to the top of steering column 24. Turning steering wheel 26, rotates steering
column in direction
E. Lever arm 116 located generally adjacent the bottom most end of steering
column 24, is rigidly
2 5 mounted to steering column 24 so as to rigidly support a yolk 118.
Rotation of steering column
24 in direction E translates yolk 118 in direction F or F' (depending on which
side of center the
steering column is turned to) a small distance sufficient to trigger switch
actuating lever 120.
Switch actuating lever 120 is electrically connected to winch 50' so as to
activate the winch. A
11
CA 02280540 1999-08-19
left hand rotation of steering wheel 26, causes a commensurate displacement in
direction F' of yolk
118 and a commensurate displacement in a similar direction then of switch
actuating lever 120.
This causes winch 50' to turn belt 122 in direction G which turns oversized
pulley wheel 124.
Pulley wheel 124 and reduction pulley 128 are rigidly mounted on a common
shaft 126. Pulley
wheel 124 is rigidly mounted to shaft 126 by means of hub 124a and spokes
124b. Thus turning
pulley wheel 124 also turns reduction pulley 128. Rotation of belt 122 in
direction G thus also
rotates belt 130 in direction G'. Rotation of belt 130 causes rotation of
forward frame 10 about
pin coupling 11 as belt 130 turns around fixed pulley 132 rigidly mounted to
shaft 11.
Turning of steering column 24 is resiliently biased to a centered position by
means
of opposed pair of springs 134 mounted to lever arm 116. Springs 134 urge the
steering column
and wheel to a normally centered position and so also resiliently bias yolk
118 to a centered
position wherein switch actuating lever 120 is in its non-actuating position.
The vehicle of the present invention may overcome, that is, ride over,
obstacles
such as log 8 or may self load in the back of a conventional pickup truck (not
shown). Firstly, the
frame 10 is elevated to its full vertical height as seen in Figure 3, by
selectively rotating the legs
to the vertical position. This allows the placement of forward lip l0a of
supporting frame 10 onto
the obstacle. Forward legs 20a and 24b are then rotated upwardly from the
vertical in direction
2 0 B', so as to rotate wheels 16a and 16b from the vertical lowered position
to an elevated position
such as used to stow the wheels after the vehicle has self loaded into the
back of a pickup truck.
Continuing rotation of the forward wheels in direction B' rotates the wheels
over the obstacle.
Rotation of the forward legs is continued until the wheels are placed onto the
far side of the
obstacle, that is the side of the obstacle opposite the vehicle and operator
sitting in seat 32.
Thus, in order to ride over log 8, wheels 16 are rotated over the top of the
obstacle
in direction B', then forwardly and downwardly in direction B until they
recontact the ground
surface 62 on the far side of log 8 thereby allowing the vehicle to proceed
with forward rolling
12
CA 02280540 1999-08-19
translation in direction D until the aft wheels also contact log 8. The aft
wheels are then cleared
over the log in the same manner employed for the forward wheels. That is, with
the aft legs
adjacent log 8, aft supporting frame 12 is lowered onto the log by rotating
aft legs 22a and 22b in
direction C'. With aft supporting frame 12 resting on the log, the rotation of
the aft legs is
continued in direction C to thereby rotate the aft wheels over the log until
they also contact ground
surface 62 so as to thereby be on the same side of the log as the forward
wheels. Continued
rotation of aft legs 22 in direction C then elevates aft supporting frame 12
up off the log to allow
the vehicle to continue its rolling translation in direction D.
With respect to the self loading of the vehicle of the present invention into
the
back of a pickup truck, initially lip l0a is placed onto the surface of the
lowered tailgate of the
truck. The front wheels are then rotated in direction B' as if clearing over
an obstacle. The
forward wheels are rotated forwardly and downwardly, i.e. in direction B,
until they contact the
bed of the pickup truck. Continued rotation of the forward legs lifts lip l0a
and the nose of
forward supporting frame 10 off the tailgate of pickup truck so that the
vehicle may be rolled
forward by actuation of the rear drive wheels in direction D until the aft
legs contact the tailgate.
The forward wheels are then retracted by rotation of the forward legs counter
to direction B into
their position shown in Figure 8. Aft supporting frame 12 is then lowered onto
the tailgate by
rotation of the aft legs in direction C'. Continued rotation of the aft legs
22 in direction C' rotates
2 0 the aft wheels until they are rotated forwardly into their position as
illustrated in Figure 8, that is,
into the confines of the box (shown in dotted outline) of the pickup truck.
Steering column may
fold down in direction E about the hinge line of hinged plates 64 as better
seen in Figure 9 for
storage. By removing two bolts (not shown) from hinged plates 64, the steering
column collapses
into its storage position. This is then the storage mode of the vehicle in the
back of the pickup
2 5 truck, ready for transportation.
As illustrated in Figure 10, selective rotation of the legs on one side of the
vehicle
allows for rolling translation of the vehicle transversely across a steep side
hill or inclined slope,
13
CA 02280540 1999-08-19
such as up to an approximately 45 degree slope, while still maintaining the
fore and aft supporting
frames generally horizontal and the vehicle operator in a generally normal
operating position.
As better seen in Figure 11, fore and aft floatation pods 66 and 68
respectively,
may be releasably coupled by means of bolts or the like, to the undersides
respectively of forward
supporting frame 10 and aft supporting frame 12. Advantageously, the
floatation pods are shaped
in plan view to correspond in shape to the undersides of the corresponding
supporting frames. The
floatation pods assist in floatation of the vehicle for water transportation.
The pods may be rigid
or may be inflatable. In Figure 11, the floatation pods have been releasably
mounted to the
undersides of the supporting frames and the floatation wheels elevated into a
generally elevated
position wherein the fore and aft legs are generally horizontally co-planar
with the fore and aft
supporting frames. This places the floatation wheels in generally co-planar
relation with the
floatation pods so that upon entry into the water, floatation of the vehicle
is buoyant, not only on
the floatation pods, but also assisted by buoyant displacement by the
floatation wheels. A
manually deployable propeller drive shaft 70 may be rotated from a generally
horizontal position
to the downwardly disposed position illustrated so as to submerge propeller
72. Propeller 72 may
be selectively engaged by engaging a power take-off (not shown) for rotation
of the propeller by
means of main propulsive unit 30. The propeller may be selectively engaged as
for example by
means of an electric clutch (not shown), as would be understood by a person
skilled in the art.
The illustrated embodiment is two wheel rear driven. A hydrostatic
transmission
and a posi-traction rear end provides drive to both rear wheels at all times.
The two flotation units,
complete with rudders (not shown) can be mounted simply by moving front wheels
forward from
their lowered position and rear wheels backward from their lowered position so
as to lower the
2 5 frame onto pins (not shown) protruding upwardly from the flotation pods.
The pins slide through
mating holes in the frame and are secured with lock pins. The device is
steered in water, the same
as on land, by electric articulation of the fore frame 10 relative to the aft
frame 12. Articulation
turns the rudders along with the flotation pods.
14
CA 02280540 1999-08-19
For use in a snow covered environment, in a third terrain capability, as
better seen
in Figure 13, a ski attachment 74 such as better seen in Figure 14, is mounted
onto, and below, the
steering column. The upper end of ski 74 is an internally or externally
splined shaft which is
journalled onto or into a corresponding mating splined shaft or aperture on or
in the lower end of
the steering column, into steering engagement therewith so that turning the
steering wheel about
axis G turns not only the steering column but also rotates the ski attachment
for steering of the
vehicle in its snow terrain mode. Removing a bolt disengages the electric
steering. the electric
steering is disengaged by an electrical switch or manually disengaged or
otherwise, thereby
locking the frame in a rigid position, with frame 10 fixed in position
relative to frame 12. In one
embodiment, the frame cannot articulate because the reduction drive is held
rigidly. The splined
ski shaft is then be slid into engagement with the steering column. Ski 74 is
manually steered.
Forward wheels 16 are rotated rearwardly and upwardly into the position
illustrated in Figure 13
so as to raise forward wheels 16 above the snow terrain level. Traction chains
or similar devices
such as plastic traction chains 76 as illustrated, may then be placed over
both fore and aft wheels
16 and 18 and the chains tensioned by selective rotation of the forward wheel
on forward legs 20.
Alternatively, traction chains 76 may be tensioned by selective rotation of
aft legs 22. With
traction chains 76 tensioned, drive power applied to aft wheels 18 rotates
traction chains 76 about
aft wheels 18 and forward wheels 16. Forward wheels 16 act as idlers. Traction
chains 76 then
2 0 provide for traction translation of the vehicle resting on ski 74 in a
forward motion over snow.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is to
2 5 be construed in accordance with the substance defined by the following
claims.
