Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to vehicles and more
particularly to a new and improved three-point cambering vehicle
having a steerable front contact and laterally spaced rear
contacts all arranged for cambering and continuous engagement
with a support surface during cornering and other maneuvers to
provide for improved vehicle maneuverability and stability.
Prior to the present invention three-point contact
vehicles have had various suspension arrangements for their
wheels or other surface contact means to stabilize the vehicle
during operation including high speed cornering maneuvers. By
way of example, in one prior art vehicle, parallelogram linkage
.~
,,.,. , , .. ,.................... - . , : . . : :
' ,, . ' ' . : .:,: ': ,: :
.-~ . .. . .
:: . ,
108'~7~jZ
and stabilizing spring means are employed to mount the rear
wheels of a three-wheel vehicle on the end of a longitudinally
extending frame so that the frame and wheels camber by equal
amounts when the vehicle is rolled during cornering. However,
with such wheel suspension the vehicle is susceptible to
tilting and instability when one of the rear wheels strikes an
obstruction. Also this prior art vehicle does not permit the
operator to make full use of his body in cambering the vehicle
for vehicle control purposes.
This invention, in contrast to the prior art, does
not involve complex wheel suspension construction and permits
the operator to naturally control camber by leaning his body
and shifting his weight from one foot to the other to roll the
vehicle for cornering or other vehicle operations. Instead of
leaning into a turn the operator may optionally remain upright
and tilt the vehicle into the turn for high speed cornering.
This invention permits the operator to take full advantage of ;;
his inherent ability to make continuous and instantaneous
adaption to lateral acceleration or to adjust to varying terrain
undulations. In this invention the operator may independently
select the degree of camber and wheel turn in accordance with
his natural stance. One of the main features of this invention
is to provide a light weight three-point vehicle which is highly
maneuverable on which the operator naturally stands and which
provides optimized lateral and fore and aft stability when the
vehicle is in motion and when stationary.
One preferred embodiment of this invention incorporates
a frame which is articulated and is therefore flexible. The
frame has a main front portion which supports a powered steerable
front wheel at a fixed caster angle. The rearward portion of
the frame includes a pair of laterally-spaced and trailing swing
10827~Z
arms which are pivoted to and on opposite sides of the front
portion for limited turning about a horizontal axis. Each arm
carries a rear wheel at its free end and the arms are operatively
connected to each other and to the front portion of the frame by
a bell crank linkage or an equivalent stabilizer which allows
only equal and opposite turning movement of the arms when the
vehicle is tilted to either side. With this arrangement camber
steering can be accomplished in addition to slip angle steering
used in conventional multi-wheeled vehicles. In addition, the
trailing arms provide appropriate support of the operator so
that the operator can make full use of his body to tilt the
vehicle for increased maneuverability and stability as well as
adjust to terrain undulations. In particular each trailing arm
of the flexible frame supports a foot pad disposed by each of
the rear wheels which is rockably mounted so that the operator
while imposing his weight on the pads can lean slightly forward
toward the front driving wheel to increase drive wheel traction.
The foot pads can be rocked in a rearward direction by the
weight of the operator to frictionally engage the rear wheels
for vehicle braking while simultaneously decreasing drive
traction by reducing front wheel loading.
In another embodiment of the invention the vehicle ~ ;
may be equipped with a powered snow tire and rear skis for
operation on snow and ice. In another preferred embodiment of
the invention the trailing arms are interconnected by cable and
pulley stabilizer means and the vehicle is manually propelled
when the operator shifts his weight from one foot to the other
as the vehicle is guided in a sinuous path. In still other
preferred embodiments of the invention ice skates and skis are
employed as the contact for the support surface instead of
wheels.
- : - -: ,. . . ~:
108~7~i2
An object, feature and advantage of this invention is
to provide a new and improved cambering vehicle with steerable
front ground contact means and laterally spaced rear ground
contact means mounted on trailing arms which are swingable in
planes on opposite sides of the vertical plane through the
longitudinal axis of the vehicle so that the ground contact
means camber by an amount equal to the tilt applied to the
vehicle by the operator as he leans in a natural manner during
cornering maneuvers.
Another feature, object and advantage of this invention
is to provide a new and improved narrow track vehicle with high
lateral acceleration potential produced by camber steering hav-
ing a steerable front wheel and laterally spaced rear wheels
mounted on trailing arms that are pivoted on a lateral axis
through a front portion of the frame of the vehicle for swinging
movement in opposite up and down directions to permit the
vehicle to be cambered.
Another object of this invention is to provide a
three-wheeled cambering vehicle having an articulated frame and
incorporating a new and improved suspension for a pair of rear
wheels which permits the vehicle operator to stand above or
along the axis of the rear wheels and which swing in separate
planes spaced a predetermined distance from a tiltable longi-
tudinal axial plane bisecting the vehicle to provide for rear
wheel camber when the operator tilts the vehicle on cornering
maneuvers.
Another feature, object and advantage of this invention
is to provide a new and improved cambering vehicle having a
steerable front driving wheel and a pair of laterally spaced
rear wheels incorporating rockable foot pads for the vehicle
operator that allow the operator to increase drive traction by
impressing body weight on the front portion of the foot pads
108'~7S'~
and the front wheel and to reduce front wheel loading and drive
traction while braking by rocking the foot pads in a rearwardly
direction causing their frictional engagement with the rear
wheels.
Another feature, object and advantage of this inven-
tion is to provide a new and improved three-wheel cambering
vehicle having a flexible frame comprising a main frame support-
ing a steerable front wheel and a pair of trailing arms; the :` .
arms support a pair of rear wheels at their free ends and are
interconnected at their forward ends to the main frame and to
each other for simultaneous equal and opposite swinging movement ~ .
with respect to each other so that the vehicle and wheels can be ~ :
cambered at will by an operator. .
Another feature, object and advantage of this invention :
is to provide a new and improved three-point contact cambering
vehicle with the contacts being skis, ice skates or wheels having
a manually steerable front center contact and left and right
rear contacts arranged on trailing arms and interconnected with
each other for up and down swinging movement in equal and
opposite directions so that the operator can optimize vehicle
operation while standing in a natural manner on the vehicle and
providing an instinctive input into the vehicle by leaning and
shifts in body weight as the vehicle traverses a course.
These and other features, objects and advantages of
this invention will be more apparent from the following detailed
description and drawings in which:
FIGURE 1 is a perspective view of a first embodiment
of the vehicle;
FIGURE 2 is a side elevational view of the vehicle
shown in FIGURE l;
FIGURE 3 is a top view of the vehicle shown in
FIGURE l;
108Z7S;2
FIGURE 4 is an end view of the first embodiment of the
vehicle with some parts removed illustrating right camber for
cornering;
FIGURE 5 is an end view of the vehicle of FIGUR$ 4 in
an upright position making a right corner turn without camber;
FIGURE 6 is a perspective view of the first embodiment
of the vehicle in a collapsed position for stowage;
FIGURE 7 is a side view obverse of the FIGURE 2 view
showing another portion of the first embodiment of the vehicle;
FIGURE 8 is a perspective view of a vehicle similar to
FIGURE 1 but modified with a seat for the vehicle operator;
FIGURE 9 is a perspective view similar to FIGURE 1
illustrating a second embodiment of the invention;
FIGURE 10 is a perspective view similar to FIGURE 1
illustrating a third embodiment of the invention;
FIGURE 11 is a perspective view of a fourth embodiment
of the invention;
FIGURE 12 is a perspective view of the vehicle of
FIGURE 11 in a collapsed position;
FIGURE 13 is a frontal perspective view of the fifth
embodiment of the invention;
FIGURE 14 is an enlarged side elevation view of a
portion of the front frame of the vehicle of FIGURE 11;
FIGURE 15 is a diagram illustrating one mode of
operation of the vehicle shown in FIGURE 11;
FIGURE 16 is a perspectiva view of a vehicle similar
to the vehicle shown in FIGURE 11 but modified with wheels
being replaced by ice skates; and
FIGURE 17 is a perspective view of a vehicle similar
to the vehicle of FIGURE 11 but modified with wheels being
replaced by snow skis.
108Z7'5Z
Turning now in greater detail to the drawings there
is shown in FIGURE 1 a cambering vehicle 12 which has a front
frame portion 14 comprising an inclined tubular sleeve 16 and
a pair of struts 18 arranged in a V joined to sleeve 16 which
extend downwardly and terminate in horizontally extending
collars 20.
The tubular sleeve 16 axially locates and rotatably
supports a rearwardly inclined steering shaft 24 which has an
upper end secured to a handle bar assembly 26 by threaded
10 fastener means 28. The lower end of the steering shaft is ;
secured to a flat support plate 30 and to a fork 32 for rotat-
ably supporting a front drive wheel 34.
The flat plate 30 supports a suitable power plant for
driving the vehicle such as a conventional internal combustion
engine 36 secured to the support plate. If desired, the plate
30 may support a battery and electric drive motor. The output
of engine 36 is shown in FIGURE 7 as a rotatable sprocket 38
which drives a front wheel sprocket 40 through a chain 42.
The engine incorporates a conventional centrifugal clutch which
drivingly engages at predetermined engine speed above idle for
vehicle drive and disengages at idle speed so that there is no
power flow to the drive wheel under idling conditions. If
desired, the front wheel may be driven by a conventional
motorcycle transmission.
Engine speed is controlled by throttle control lever
44 mounted on the right wing of the handle bar assembly and -~
connected to the engine throttle by cable 45. The control
lever 44 is manually adjusted by the operator 46 to set the
engine at selected throttle openings from idle to wide open
throttle.
The vehicle also has a pair of laterally spaced
trailing arms 56 and 58 extending rearwardly from front frame
108Z7SZ
portion 14. As shown in FIGURES 1-3 the arms are mounted for
limited swinging movement on a pivot shaft 60 which laterally
extends through the eyes of axially aligned frame collars 20
and through a cylindrical spacer 61 connecting the collars to
each other. The pivot shaft is maintained in position by
retainer nuts 62 threaded on the ends of the shaft outboard
of the ends of the trailing arms. The trailing arms 56 and 58
are of equal dimensions and extend rearwardly from the laterally
extending pivot rod 60 and each has a pair of laterally spaced
support brackets 63 and 64 welded to the outboard sides thereof.
Axle shafts 68 and 70 extend through these brackets and through
the ends of the trailing arms to rotatably support rear wheels
72 and 74, respectively. As shown by FIGURE 3 the trailing
arms 56 and 58 respectively swing in planes Pl and P2 having a
predetermined relationship with each other and with a
centralized axial plane through roll axis A bisecting the
vehicle. The planes may be parallel and their relationship
remains the same as they are rolled when the vehicle is cambered.
Foot pads 76 and 78 for supporting the operator 46
are disposed above wheels 72 and 74, respectively, and are
mounted for limited rocking motion with respect to the trailing
arms 56 and 58. As shown, each pad has a pair of depending
laterally spaced ears 80 and 82 which straddle the corresponding
rear wheel. The ears 80 and 82 are pivotally connected to their
associated support brackets 63 and 64 by pivot bolt means 84
and 86 so that the foot pads can be rocked between the inclined
forward position where the pads 76, 78 engage their respective
arms 56, 58 and an inclined rearward position. Because of the
forward tilt of the foot pads 76 and 78 shown in FIGURE 1, the
operator will tend to lean forwardly on the front part of the
foot pads and on the handle bars thus applying body weight to
the front drive wheel. Under these conditions the load on the
108~75Z
front drive wheel is naturally increased for improved vehicle
traction and performance. The foot pads, if desired, may be
arranged with little or no forward tilt in normal position.
Secured to the underside of each foot pad in alignment
with the corresponding rear wheel is an arcuate friction brake
member 88. These brake members are adapted to frictionally
engage the peripheral surface of the associated rear wheel for
vehicle braking when the operator transfers his weight to his
heels to rock the pads rearwardly from the FIGURE 1 position to
the FIGURE 2 position. When the operator rocks rearwardly for
braking, load is simultaneously removed from the front wheel to
reduce driving traction in those vehicle arrangements that em-
ploy a centrifugal clutch.
The trailing arms 56 and 58 of the frame are inter-
connected to each other and to the front frame member 14 by a
bell crank linkage comprising generally parallel side links 90
and 92 and by an upper bell crank 94. The side links are
pivotally connected at their lower end to arms 56 and 58,
respectively, by pivot bolt members 96 and 98. The upper ends
of links 90 and 92 are pivotally connected to the bell crank 94
by pivot bolt means 100 and 102. The bell crank 94 is pivotally
connected to a threaded pivot pin 104 that projects axially
from an extension 106 from the front frame member 14. Pivot
pin 104 is inserted through a circular opening formed centrally
in the cross link 94 and a retaining knob 108 is threaded on
the end of the pivot pin to retain the bell crank thereon.
Normally the bell crank 94 is rocked about the axis provided by
the pin 104 when the vehicle is cambered. However, to completely
stabilize the vehicle at rest, knob 108 can be advanced on the
pivot pin to a position whereby the bell crank is held fast to
the frame extension 106. With the bell crank 94 rigidly
secured to the frame, the side links 90 and 92 and trailing
108'~ ~SZ
arms are rigidly secured so that the vehicle is held stationary
in an upright position for parking purposes. Obviously, the
vehicle could also be driven with the bell crank fixed, in which
case cambering control would be lost but rockable traction and
brake control would be retained.
With the laterally spaced rear wheels forming a foot
support base and with the steerable front wheel having ground
contact at a forward point on a longitudinal axis bisecting the
base, a three-wheeled vehicle having maximized natural lateral
stability for straight ahead and cornering operations at all
speeds is provided. Since the center of gravity of the vehicle
and operator is directly above the triangle t defined by the
wheel contact points with the ground during straight ahead
driving, the vehicle is naturally stable. When the vehicle is
cornered by the operator leaning into a turn, the resultant of
gravitational and centrifugal forces is also naturally directed
through triangle t for stabilized turns.
The vehicle is readily mounted by stepping on the
foot pads in any sequence and the handle bars 26 are gripped
without any noticeable balancing effort. The operator merely
assumes his normal stance or one with a slight hand pressure
on the handle bar. Assuming that the vehicle engine has been
started by a conventional recoil hand starter 109 and with the
operator's body weight distributed on the front part of the
foot pads, the throttle is opened by operator to proceed in a
straight course. Lateral stability is provided by the natural
upright stance of the operator. Assuming that a tight right
turn is to be negotiated, the operator can turn the handle bar
slightly to the right and readily lean into the turn, thus
shifting weight to tilt or roll the vehicle about its roll axis
as illustrated in FIGURE 4. This rolling action causes the
front end of the trailing arm 56 to be raised and the front end
iO8'~ JfS2
of trailing arm 58 to be lowered. Thus, arm 56 will pivot in
its plane counterclockwise about pivot axis 60 and arm 58 will
concurrently pivot in its plane clockwise about the axis 60
through the same angle. The bell crank linkage interconnecting
the trailing arms and front wheel support ensures that the
pivotal movement of the arms is equal and opposite. When the
vehicle is rolled, all wheels remain in contact with the ground
and camber by an amount equal to vehicle roll. When the
operator leans into the corner to corner the vehicle, the
resultant force due to gravity and centrifugal force passes
through the triangle t defined by the wheel contact points for
maximized cornering stability. Since this triangular area is
fairly large as provided by the basic structural dimensions of
the vehicle, there is no need for critical positioning of the
operator with respect to the wheels as with a motorcycle or
other two-wheel vehicle. Additionally, there is no need for
critical steering adjustments to keep a precise relationship
between speed, turning radius and camber angle so that severe
handling maneuvers can be accomplished with ease and precision
with minimal driving skill.
Camber steering to the left is opposite to right
camber steering described above and further description of
such turns is therefore not necessary. It will be appreciated
however that when traversing a winding path, the operator can
make maximum use of his natural leaning ability to lean from
one side to the other to accordingly use ground reaction to
produce a rolling movement to camber the vehicle to the left -~ -
or right to compensate for centrifugal forces occurring during
such vehicle maneuvers. If desired the operator may remain
standing in an upright position and tilt the vehicle to either
side into a turn for cornering. In any event, with camber
steering the steerable front wheel requires little angular
11
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108Z75Z
change for tight turn operation.
While cornering ability is sacrificed, turns without
camber steering can also be made with this invention. As shown
in FIGURE 5, for example, the handle bar 26 assembly can be
turned to the right to move the front wheel through a relatively
large angle while the vehicle is maintained upright by the
vertical stance of the operator (not shown) to steer the vehicle
into a desired right turn. Atslow speeds, there is obviously
little or no tendency on the part of the operator to lean into
a turn~
Stability is provided when the vehicle is running
over uneven ground by reason of the forward location of the
trailing arm pivots and bell crank linkage. If there is a rise
in the ground under one side of the vehicle, the rear wheel
encountering the obstruction may rise without substantial tilt
of the vehicle as would occur in other three-wheel vehicles
with comparable lateral w'neel base. Moreover, the operator may
maintain his vertical posture while one wheel rises. ~ ,
For portability or storage the hand knob 108 can be
removed from pivot bolt 104 so that the bell crank linkage 90, ~ ~ -
92 and 94 can be disconnected from the steering column and the
vehicle folded into a collapsed position as illustrated in
FIGURE 6. In this folded position the steering column is
positioned closely adjacent to the trailing arms to provide a
highly compact package so that the vehicle can be easily carried ;~
or stored using minimal space.
FIGURE 8 discloses substantially the same vehicle as
illustrated in FIGURE l with similar numerals depicting similar
parts, incorporating an optional seating structure 114 for
supporting the vehicle operator. This structure which may be
readily attached to the frame comprises a central tubular spacer
116 mounted on the pivot shaft 60 between collars 20 which has
12
~08'~7~Z
a pair of diagonally extending tubular struts 118 that converge
to terminal positions on opposite sides of the free end of
longitudinally extending upper bar 120. Threaded fastener means
122 secure the ends of the struts 118 to the upper bar 120 which
in turn is secured to projecting ears 124 of the frame by a bolt
126. The upper bar 120 terminates at its free end in a tubular
sleeve 128 which receives a cylindrical post 130 of a seat
assembly 132.
The seat assembly has an operator's seat 134 secured
in a conventional manner to the upper end thereof. The seat
assembly is secured in adjusted vertical position to suit the
operator's physique by tightening a set screw 138 threaded
through the wall of the sleeve 128 into engagement with the
seat post.
In operation of this embodiment, the operator can sit
on the seat and rest his feet on the foot pads 76, 78 supported
by the trailing arms 56 and 58 which provide good lateral
stability. As in the embodiment of FIGURE 1, the foot pads are
pivoted on the trailing arms to tilt forwardly so that the
operator can stand and lean forward to increase loading on the
front wheel when increased traction is desired. When the pads
are tilted rearwardly by the operator shifting his weight to
the rear thereof, brakes 88 engage the rear wheels 72 and 74 for
vehicle braking. Riding and control of the vehicle of FIGURE
8 is similar to that of a conventional bicycle or motorcycle
but with much improved lateral stability at rest and low speeds.
The vehicle can be readily cambered by the operator by leaning
his upper torso and/or shifting his foot pressure to the left or
right as desired for left and right cornering. For improved
control during high speed cornering or when traversing a winding
course requiring rapid changes between left and right camber,
the operator can readily raise from the seat and stand on the
13
~08'~7~Z
foot pads and lean in either direction to maximize the use of
his body weight for cambering the vehicle.
FIGURE 9 illustrates another variation of the
cambering vehicle of this invention and incorporates skis 146
and 148 for gliding support on snow in place of the rear wheels
of the previous embodiments. As shown, the skis are mounted
on pivot shafts 150, 152 which are secured to the free ends of
trailing arms 56 and 58. In addition to pivotally supporting
skis 146 and 148, the pivot shafts 150 and 152 also pivotally
mount foot pads 154 and 156 on which the operator stands. As in
the previous embodiments, the operator can tilt the foot pads
forward so that his body weight loads the steerable front snow
tire 158 for increased traction. When the pads are tilted
rearwardly, the rear ends thereof dig into the snow for vehicle
braking. A steering wheel assembly 160 is employed in place of
the handle bar assembly of the previous embodiment to provide an
alternate form of steering control. The steering wheel assembly ~ ?
comprises a circular steering wheel 162 connected by radial
spokes 164 to a central shaft 166. The central shaft is con-
nected to the steering column by the threaded fastener means 28so that the steering wheel can be readily turned to any position.
If desired the steering w~eel of this embodiment or the handle
bar assembly of the other embodiments of the vehicle can be ;~
telescopically mounted with respect to the steering column 24 in
any conventional manner for adjustment to different heights to
suit the operator. Engine throttle opening is controlled by an
inner ring 168 which is operatively connected to the engine
throttle valve by suitable cable means (not shown). The ring is
rotatably supported on the steering wheel assembly by rotatable
central collar 169 and can be manually turned by the operator's
fingers to open the throttle. Spring means (not shown) are
preferably employed to return the throttle control ring to a
14
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: ~ . . .. : . .. - ~
~08'~75~
closed throttle position when released by the operator.
The operation of the FIGURE 9 embodiment of the vehicle
is similar to operation of the previous embodiments. The
operator standing on the foot pads can camber the vehicle, skis
and front wheel for cornering. The active suspension system for
the skis permits the vehicle to negotiate a tighter turn than
would be otherwise possible. For operation on ice, ice skates
could be substituted for the skis.
FIGURE 10 shows a portion of a cambering vehicle to
illustrate another variation of this invention. As shown the
vehicle has a steering shaft 170 mounted for turning movement in
the tubular sleeve 172 of the frame 173. The steering shaft is
drivingly connected to a large wheel fork 174 to accommodate the
large diameter front wheel 176. The front wheel is frictionally
driven by a motor 178 secured to the fork 174 by suitable support
bracket means (not shown). The motor 178 has a friction roller
180 as an output which frictionally engages and drives the top of
wheel 176. The front frame portion 173 is modified from the
FIGURE 1 embodiment to accommodate the large front wheel by
replacing pivot shaft 60 with stub shafts 182 and 184 on which
the trailing arms 56 and 58 are mounted for limited pivotal
movement in planes parallel to the central plane bisecting the
vehicle. To provide for greater stability with larger rear wheels
left and right foot pads 186 and 188 are mounted for rocking
movement below the rotational axis of the rear wheels 190 and 192
between a forward tilt position for vehicle drive and a rearward
tilt position for vehicle braking. Integral braking members 194
laterally extending from the front ends of foot pads are adapted
to engage the rear wheels when the foot pads are tilted rearwardly
by the operator. As shown, the rear wheels in this variation of
the invention are mounted on offset axles 196 extending through
supporting bracket 198 secured to the trailing arms. With a lower
108;2~S~:
center of gravity and larger wheels, another variation of the
invention is provided. As in the previous embodiments of this
invention this variation is a highly stable general purpose
vehicle that is economical to operate and easy to maintain.
Also as in the previous embodiments cambering is provided to
increase vehicle controllability and improved steerability and
maneuverability.
By having the vehicle operator standing directly over
the rear wheels as in FIGURE 1 or adjacent to the rear wheels
as in FIGURE 10, the operator can provide a natural input into
the vehicle for improved vehicle stability at rest, as well as
while moving. This input is similar to a person's instinctive
response in maintaining equilibrium when standing as well as when
walking or running. While on the vehicle of this invention, the
operator feels as if he is supported directly by the ground and
thus can instinctively adjust his weight distribution to his feet
or lean his body for vehicle balancing purposes. With the rear
wheels at the operator's feet and a steerable wheel provided
forward of the rear wheels, improved manual guidance is avail-
able for the operator. When cornering using camber and slipangle steering of this invention, the manual angular input into
the steerable front wheel is sharply reduced as compared to slip
angle steering with conventional multi-wheel vehicles making the
same turn. Particularly when standing on the foot pads, improved
stabilized cornering for any given speed is obtained by cambering
the vehicle an appropriate amount to offset centrifugal forces.
FIGURES 11 through 15 illustrate another embodiment of
the vehicle of this invention which is particularly adaptable to
be propelled in a forward direction by a natural input from the
vehicle operator through the timed shifting of his weight from
one foot to the other coordinated with the left and right cambered
steering of the vehicle in a sinuous path. This embodiment of the
16
108~75Z
vehicle is identified by reference numeral 200 and has a front
frame portion 202 comprising an inclined and elongated cylin-
drical main frame 204 that axially locates and rotatably supports
a tubular steering shaft 206 extending therethrough. The upper
end of steering shaft 206 telescopically mounts the centralized
connector shaft 207 of handle bar assembly 208. A clamp 209
carried by the upper end of shaft 206 can be constricted by con-
ventional threaded fastener means to hold the handle bar assembly
in adjusted position. The steering shaft 206 has a lower
bifurcated end 210 which provides a fork for steerable front
wheel 212. This wheel rotates on an axle 213 which extends
transversely through and is supported by the fork. The vehicle
has a pair of tubular trailing arms 214 and 216 which respectively
have their forward ends secured in sockets 218 and 220 of right
and left side pulley assemblies 222 and 224. The pulley assemblies
222 and 224 are mounted for turning movement on a horizontally
extending pivot shaft 226 which is supported by the front frame
portion 204. With this construction each arm is mounted for up
and down swinging movement on the axis provided by the pivot shaft
226 and on opposite sides of main frame 204.
Right and left rear wheels 230 and 232 are rotatably
mounted on axles which extend laterally and outwardly from the
free end of trailing arms 214 and 216, respectively. In addition
to supporting the rear wheels 230 and 232 the end of arms 214
and 216 have mounting brackets 236 and 238 secured respectively
thereto for right and left foot pads 240 and 242 adapted to
support a vehicle operator in a manner such as disclosed in ~-
connection with the embodiment of FIGURE 1. As best shown in -~
FIGURES 11 and 13, the foot pads 240 and 242 are located laterally
inboard of the rear wheels 230 and 232 and are tiltably mounted
on pivot pins 244 and 246 carried by brackets 236 and 238,
respectively. Foot pad 240 disposed inboard of wheels 230 has an
17
.: . .
... . . : .
108Z7SZ
outwardly extending tubular friction brake member 248 secured
thereto that directly engages the outer periphery of the wheel
230 when the pad is rocked rearwardly on pivot pin 244 by the
operator to effect braking of wheel 230. In a forward tilt
position of pad 240 the brake member 248 is spaced from wheel 230
as in the previous embodiments so that the wheel can freely
rotate. In a like manner, foot pad 242 has an outwardly extend-
ing tubular brake member 250 secured thereto which is adapted to
directly engage and brake the left rear wheel 232 when pad 242 is
rocked rearwardly on pivot pin 246 by the vehicle operator. In
the forward tilt position of this pad, the brake member is spaced
from the wheel so that it may roll freely.
The trailing arms 214 and 216 are interconnected in a
way so that the swinging of one arm on pivot shaft 226 in one
direction will tend to swing the other arm automatically in the
opposite direction. To this end the arms are mechanically
interconnected by an endless cable 264 which extends around right
and left side trailing arm pulleys 266 and 268 and a pair of
transverse upper pulleys 270 and 272. Cable 264 leads from right
side pulley 266 around pulley 270 and from pulley 270 around left
side pulley 268. From pulley 268 the cable leads around upper -
pulley 272 and back to the right side pulley 266. Cable 264 is
connected to pulleys 266, 268 and 270 by any suitable means to
prevent slippage. The pulley 266 forms part of pulley assembly
222 and is rotatable by trailing arm 214; likewise, pulley 268 is
part of pulley assembly 224 and is turned by rotation of trailing
arm 216. Pulleys 270 and 272 are rotatably supported on clevises
274 and 276 which are adjustably interconnected by a cable 278. --~
As shown, the cable 278 loops through the upper end of clevis 276
and straddling the tubular main frame 204 extends around the right
and left sides of a transversely extending tubular shoulder 280
secured to the main frame 204. The terminal ends of cable 278 ;~
18
108~7S~
are connected by threaded cable tensioners 282 and 284 to the
clevis 274.
Clevis 276 and its pulley 272 are adjustably mounted
with respect to a bracket 277 secured to and extending along an
upper portion of elongated tubular main frame 204. As shown,
the pulley 272 and its associated clevis 276 are supported by a
pivot pin 288 which extends through and rotatably supports
pulley 272. The inner end of the pin 288 is removably seated
in a cylindrical bearing 290 integral with tubular main frame
10 204 and extends outwardly from this bearing through the circular -
upper eye 292 of a keyhole slot 294. Pin 288 terminates in a
handle 296 and has a necked or slotted intermediate portion 298
which fits within the narrow track of the keyhole slot 294.
With this construction the operator can grasp handle 296 and pull
the end of pin 288 out of bearing 290. The handle 296 can be
subsequently turned to align the slotted portion 298 of the pin
with the narrow track of the keyhole slot so that the clevis 276
and pulley 272 can be lowered as the main frame 202 is being ~ -:
tilted from the vehicle operating position of FIGURE 11 to the
stowed position shown in FIGURE 12. When the lower eye 300 of ~:
the keyhole slot is reached, the pin 288 can be pushed inwardly
into engagement with a lower bearing 304 integral with main frame
204. In this position the slotted portion 298 of the pin 288 is
misaligned with respect to the narrow track of the keyhole slot
so that the vehicle is latched in the stowed position. In a
similar manner described in connection with the folding of the
vehicle the pin 288 can be disengaged with the lower bearing 304 ;
and the pin and clevis moved upwardly as the main frame is turned :
from the stowed position of FIGURE 12 to the operating position :~
of FIGURE 11.
Pulley 270 can be prevented from turning to thereby
hold the vehicle in an upright position by the manual turning of :
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locking handle 306. By turning this handle, threaded means 308
is drawn toward the handle so that the sides of clevis 274
frictionally engage the sides of pulley 270 to lock the 'crailing
arms together for vehicle parking or for stowage purposes.
In one preferred mode of operation of this embodiment
of the invention, the operator can step on one foot pad using
his other foot to push off the support surface to give the
vehicle an initial velocity, shown as vector Vl in FIGURE 15.
After pushing off, the operator places his feet on their
respective foot pads so that operator input can be imparted into
the vehicle for forward propulsion. Initially the operator
distributes his weight to one foot and camber steers the vehicle
in an arcuate path about a center point l shown in the sinuous
right and left tire paths Tl and T2. With the vehicle turning on
such an arcuate path, the right rear wheel has a turning radius
Rl which is greater than the turning radius R2 of the inside or
left rear wheel. While holding the circular path of the vehicle
substantially constant during this turning action and as he leans
the vehicle into the turn the operator shifts his weight from his ~ ~
20 right to his left foot and thus to the left wheel. The shifting ;
of the operator's center of gravity during this action is shown
by curved path G in FIGURE 15. Since the angular momentum has
not changed, the shift of the operator's mass to a smaller radius
will naturally result in an increase in vehicle velocity indicated
as vector V2. The operator subsequently cambers and steers the ~-
vehicle in an opposite direction so that it describes an arcuate
path about another center point such as center point 2 Since
at the beginning of the second half of the operating cycle the
mass of the operator is over the left rear wheel, velocity can be ~ ,
again increased by the operator shifting his weight from his left
to his right foot. Thus the operator's mass is moved from radius
R3 to the smaller radius R4 to again increase net velocity. By
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, ' ' .' ' " ' . ' ... ' : ' ~ . '~ , ': . ~
108;~752
repeating this action a net forward travel of the vehicle is
achieved as indicated by the directional arrow D in FIGURE 15.
The cambering of the vehicle during the work cycle facilitates
operat,ion. With cambering, the track of the vehicle is widened
so that the amount of work per cycle is increased. The self
propulsion is most effective on flat smooth surfaces where speeds
approaching 20 m.p.h. may be obtained.
While the manually propelled cambering vehicle has
been thus far illustrated and described with wheels providing
the three-point contact, ice runners or skates may be readily
substituted for the wheels. Such a modification is shown in
FIGURE 16 in which vehicle 200' has frame and stabilizer elements
which are basically the same as corresponding elements of the
vehicle 200 of the FIGURE 11 construction. This particular ~,
modification has a main frame 204' that supports tubular steering
shaft 206'. Manual handlebar assembly 208' is operatively ,~
connected to the upper end of the steering shaft so that the
steering shaft can be manually turned by the vehicle operator. ;
The lower bifurcated end 210' of the steering shaft supports the
transverse axle 213l on which ice skate 320 is mounted. In a like
manner right and left ice skates 322 and 324 are secured on right
and left axles 326 and 328 extending laterally from the end of
the trailing arms 214' and 216' respectively. The cable and
pulley stabilizer interconnection is the same as described in
connection with the FIGURE 11 construction so that further
detailed description of this embodiment is not necessary.
In operation on a supporting ice surface, an operator
(not shown) can distribute his body weight to the right and left
foot pads 240' and 242' and provide a natural shift in weight
between these two laterally spaced supports while manually
steering the vehicle in a sinuous course to produce a net forward
travel as described in connection with FIGURE 150 As with the
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108Z7~2
wheeled version, cambering of the vehicle is preferred when it is
being powered by the successive weight shifts of the operator.
Thus, as the operator shifts his weight from one foot to the other
the vehicle is progressively rolled or cambered so that the track
of the rear wheels is progressively increased (not illustrated
in FIGURE 15) during each half of the work cycle so that the
amount of work is increased.
Instead of ice skates, the vehicle of FIGURE 11 may
be readily provided with snow skis for downhill operation on
snow. Such a modification is shown in FIGURE 17 in which
vehicle 200'' has a main frame 204'' that supports the tubular
steering shaft 206''. Manual handlebar assembly 208'' is
operatively connected to the upper end of the tubular steering
shaft. The lower bifurcated end 210'' of the steering shaft
supports the transverse axle 213'' on which snow ski 350 is
mountedO Right and left snow skis 354 and 356 are secured on
the transverse right and left axles carried by the trailing arms
214'' and 216'' respectively. As in the other embodiments the
cable and pulley stabilizer interconnection between the two
trailing arms is the same as described in connection with
FIGURE 11 and further description is not needed.
In downhill operation, the operator can stand on the
foot pads 240'' and 242'' and distribute his body weight as he
begins the downhill run on snow. With the steering input pro-
vided by the manual manipulation of the handlebars 208'' and with
the improved lateral and fore and aft stability provided by this
vehicle, the operator can perform the same basic cambering turns
and other maneuvers as a skier with snow skis attached to his
feet. With the improved stability and maneuverability provided
by this vehicle, a novice operator can readily traverse a slope
performing turns as an experienced skier can accomplish with
foot mounted snow skiso While this invention can be used by
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novice skiers as a training aid to learn the art of skiing, it
may also be used by the more experienced skiers as a recreational
vehicle. While the vehicle has been described with foot pads on
the trailing arms various modifications can be made so that the
feet of the operator are supported directly on the rear skis which
in turn are pivoted to the ends of the trailing arms.
The detailed description and illustrations of the
preferred embodiments of this invention for the purpose of
explaining the principles thereof are not to be considered as
limiting or restricting the invention since many modifications
may be made by the exercise of skill in the art without departing
from the scope of the invention as set forth in the following
claims.
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