Note: Descriptions are shown in the official language in which they were submitted.
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~ -' This invention relates to a metho~ of manually propel-
ling a vehicle and more particularly to a new and improved method
20 of propelling a multi-point surface contact cambering vehicle on
which the operator stands and shifts his body weight as he steers
the vehicle in a sinuous path to produce a net forward travel.
Prior to the present invention a num~ffer of three-point
cambfering vehicles have been devised to provide an efficient and
highly maneuverable personal vehicle suitable for a wide range of
uses and for different age groups. While many of these applica-
tions have considerable merit they generally support the operator
in a manner such that the operator is unable to put a manual
input into the vehicle for optimized cambering maneuvers and for
?O manual propulsion in traversing any desired course. Furthermore,
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these prior vehicles are generally not suitable for any long
distance manual propulsion by the vehicle operator while the
operator is supported on the vehicle.
The manually propelled cambering vehicle preferably
has a main frame portion extending upwardly at a fixed caster
angle which supports a steerable front contact such as a ground
engaging wheel. The rearward portion of the frame includes a
pair of laterally spaced trailing arms which are pivoted to and
which are supported on opposite sides of the main frame for
limited turning about a horizontal axis. Each arm carries a
rear wheel at its free end and the arms are operatively con-
nected to each other and to the main frame by cable and pulley
stabilizer means. 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 to produce a net forward
travel. In another preferred construction the vehicle may be
equipped with ice skates as contact for support surfaces instead
of wheels.
It is accordingly a feature, object and advantage of
this invention to provide a new and improved method of manually
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propelling a three-point cambering vehicle having an upright
main frame, a steerable front contact, a pair of trailing arms
pivoted at their forward ends to the main frame and extending
rearwardly therefrom and having free end portions each mounting
a support surface contact as well as foot receiving means to
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allow the operator to naturally stand on the vehicle and grasp
the steering mechanism to camber the vehicle about alternating
left and right centers while shifting his body weight into the
turns to effect a net forward propulsion of the vehicle.
Another feature, object and advantage of this invention
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is to provide a new and improved method of operating a three-
point surface contact cambering vehicle in which the vehicle
operator, standing on the vehicle, provides alternating physical
stroking inputs into the left and right trailing arms while
turning the vehicle about a series of left and right side turning
centers to thereby manually propel the vehicle on a course
located between the turning centers.
A further feature, object and advantage of this
invention is to provide a new and improved method of manually
propelling a three-wheel cambering vehicle which allows the
operator to naturally stand on the vehicle and negotiate a
series of left and right turns while continuously transferring
his body weight toward turning centers to conserve angular
momentum and thereby effect a resultant forward direction of
vehicle travel.
These and other features, objects and advantages of
this invention will be more apparent from the following detailed
description and drawing in which:
FIG. 1 is a perspective view of a manually propelled
vehicle according to this invention in an upright or standing
.~ positionO
FIG. 2 is a perspective view of the vehicle of FIGo 1
'~ in a collapsed position.
- FIG. 3 ~s a front perspective view of a portion of the
i,
vehicle of FIG. lo
FIG. 4 is an enlarged side elevation view of a portion
of the front frame of the vehicle of FIG. 1.
`` FIG. 5 is a diagram illustrating a preferred mode of
operation of the vehicle shown in FIG. 1.
!` 30 FIG. 6 is a perspective view of a vehicle similar to
the vehicle shown in FIG. 1 but having ice skates instead of
wheels as support contacts.
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Turning now in greater detail to the drawing, FIGS. 1
through 4 illustrate a three-wheel cambering vehicle according
to this invention which can be readily propelled in a forward
direction by the input of natural physical forces from the
v'ehicle operator through the timed shifting of the operator's
weight from one foot to the other which is coordinated with the
left and right cambered steering of the vehicle in a sinuous
path. This preferred embodiment of the vehicle is identified in
the drawing by reference numeral 10 and has a front frame portion
12 comprising an inclined and elongated cylindrical main frame
14 that axially locates and rotatably supports a tubular steer-
ing shaft 16 extending therethrough. The upper end of steering
shaft 16 telescopically mounts the centralized connector shaft
17 of handle bar assembly 18. A clamp 19 carried by the upper
end of shaft 16 can be constricted by conventional threaded
fastener means to hold the handle bar assembly in adjusted
position. The steering shaft 16 h~s a lower bifurcated end 20
which provides a fork for steerable front wheel 22. This wheel
rotates on an axle 23 which extends transversely through and is
supported by the fork. The vehicle has a pair of tubular trail-
ing arms 24 and 26 which respectively have their forward ends
secured in sockets 28 and 30 of right and left side pulley
assemblies 32 and 34. The pulley assemblies 32 and 34 are
mounted for turning movement on a horizontally extending pivot
shaft 36 which is supported by the front frame portion 12. With
this construction each arm is mounted for up and down swinging
movement on the axis provided by the pivot shaft 36 and on
opposite sides of main frame 14.
Right and left rear wheels 40 and 42 are rotatably
mounted on axles which extend laterally and outwardly from the
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free end of trailing arms 24 and 26 respectivelyO In addition
to supporting the rear wheels 40 and 42 the end of arms 24 and
26 have mounting brackets 46 and 48 secured respectively thereto
for right and left foot pads 50 and 52 adapted to support a
vehicle operator. In this connection the vehicle operator may
place his feet on the foot pads and stand in a natural manner
while grasping the right and left hand grips of the handle bar
assembly. As best shown in FIGS. 1-3, the foot pads 50 and 52
are located laterally inboard of the rear wheels 40 and 42 and
are tiltably mounted on pivot pins 54 and 56 carried by brackets
46 and 48, respectively. Foot pad 50 disposed inboard of wheel
40 has an outwardly extending tubular friction brake member 58
secured thereto that directly engages the outer periphery of the
wheel 40 when the pad is rocked rearwardly on pivot pin 54 by the
operator to effect braking of wheel 40. In a forward tilt
position of pad 50 the brake member 58 is spaced from wheel 40 so
that the wheel can freely rotate. In a like manner, foot pad 52
has an outwardly extending tubular brake member 60 secured
thereto which is adapted to directly engage and brake the left
rear wheel 42 when pad 52 is rocked rearwardly on pivot pin 56 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
freelyO
The trailing arms 24 and 26 are interconnected in a way
so that the swinging of one arm on pivot shaft 36 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 64 which extends around right and left side
trailing arm pulleys 66 and 68 and a pair of transverse upper
pulleys 70 and 72. Cable 64 leads from right side pulley 66
around pulley 70 and from pulley 70 around left side pulley 68.
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From pulley 68 the cable leads around upper pulley 72 and back
to the: right side pulley 66. Cable 64 is connected to pulleys
66, 68 and 70 by any suitable means to prevent slippage. The
pulley 66 forms part of pulley assembly 32 and is rotatable by
trailing arm 24; likewise, pulley 68 is part of pulley assembly
34 and is turned by rotation of trailing arm 26. Pulleys 70 and
72 are rotatably supported on clevises 74 and 76 which are
adjustably interconnected by a cable 78. As shown, the cable 78
loops through the upper end of clevis 76 and, straddling the
tubular main frame 14, extends around the right and left sides
of a transversely extending tubular shoulder 80 secured to the
main frame 14. The terminal ends of cable 78 are connected by
threaded cable tensioners 82 and 84 to the clevis 74.
Clevis 76 and its pulley 72 are adjustably mounted
with respect to a bracket 77 secured to and extending along an
upper portion of elongated tubular main frame 14. As shown,
the pulley 72 and its associated clevis 76 are supported by a ~:~
pivot pin 88 which extends through and rotatably supports pulley ;
72. The inner end of the pin 88 is removably seated in a cylin~
drical bearing 90 integral with tubular main frame 14 and extends
outwardly from this bearing through the circular upper eye 92
of a keyhole slot 94. Pin 88 terminates in a handle 96 and has ::
a necked or slotted intermediate portion 98 which fits within
the narrow track of the keyhole slot 94O With this construction
the operator can grasp handle 96 and pull the end of pin 88 out
of bearing 90. The handle 96 can be subsequently turned to
align the slotted portion 98 of the pin with the narrow track
of the keyhole slot so that the clevis 76 and pulley 72 can be
lowered as the main frame 12 is being tilted from the vehicle
operating position of FIGURE 1 to the stowed position shown in
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FIGURE 2. When the lower eye 100 of the keyhole slot is reached,
the pin 88 can be pushed inwardly into engagement with a lower
bearing 104 integral with main frame 14. In this position the
slotted portion 98 of the pin 88 is misaligned with respect to
the narrow track of the keyhole slot 30 that the vehicle is
latched in the stowed position. In a similar manner described
in connection with the folding of the vehicle the pin 88 can be
disengaged with the lower bearing 104 and the pin and clevis
moved upwardly as the main frame is turned from the stowed
position of FIGURE 2 to the operating position of FIGURE 1.
Pulley 70 can be prevented from turning to thereby
hold the vehicle in an upright position by the manual turning
of locking handle 106. By turning this handle, threaded means
108 is drawn toward the handle so that the sides of clevis 74
frictionally engage the sides of pulley 70 to lock the trailing
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 5.
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 ~1 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
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he leans the vehicle into the turn the operator shifts his weight
from his 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 5. 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
camhers 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 repeating this action a
net forward travel of the vehicle is achieved as indicated by the
directional arrow D in FIGURE 5. The cambering of the vehicle
during the work cycle facilitates operation. 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 mph may
be obtained.
While the manually propelled cambering vehicle has
been thus f~r 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 6 in which vehicle lO' has frame and stabilizer elements
which are basically the same as corresponding elements of the
vehicle lO of the FIGURE 1 construction. This particular modifi-
cation has a main frame 14' that supports tubular steering shaft
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16'. Manual handle bar assembly 18' 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 20' of the steering shaft supports the
transverse axle 23' on which ice skate 120 is mounted. In a
like manner right and left ice skates 122 and 124 are secured
on right and left axles 126 and 128 extending laterally from
the end of the trailing arms 24' and 26' respectively. T~e
cable and pulley stabilizer interconnection is the same as
described in connection with the FIGURE 1 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 50' and 52' and provide a natural shift in weight
between these two laterally spaced supports while manually steer-
ing the vehicle in a sinuous course to produce a net forward
travel as described in connection with FIGURE 5. As with the
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 5) during each half of the work cycle so
that the amount of work is increased.
The detailed description and illustrations of the pre-
ferred embodiments of this invention for the purpose of explain-
ing the principles and methods thereof are not to be considered
as limiting or restricting the invention since ~lany 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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