Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a flexible paddle wheel
structure for and in particular to a paddle wheel construction in
which flexible paddles are supported between two wheel-1ike members
having ~lexible rims.
Paddle wheels have been used for propulsion, generally
of rigid paddles surrounding an axle. A major problem of such paddles
is damage ~hen meeting an obstacle. Spring loaded paddles have been
prcposed,the-paddles being displaced against a spring load when
meeting an obstacle Ho~ever, such spring loading must always be
strong enough to prevent displacement of the paddles under normal
propulsion loading. It is very difficult to provide a structure ~;
which i~ stiff enough to avoid di~placement during propulsion and yet
displace readily when meeting an obstacle.
The present invention provides a paddle wheel structure
camprising two axially spaced wheel-like members having flexible rims,
with a plurality of pairs of transverse flexible members extending
between the rims, the transverse members of a pair spaced radially
and a flexible membrane extending between each pair of transverse ~:
members, to form a plurality of radial paddles extending between the
wheel-like members. The transverse members can be attached to
attachment members extending around, and/or over the ring.
In its simplest form the invention can comprise an
axially spaced pair of wheels on a common axle and having rubber
tires thereon, and circumferentially extending chains, similar to
snow-chains on each tire, and radially spaced pairs of cables extending
between the chains on the wheels. A tube of rubberized -Fabric, or
similar material, extends over each pair of cables to form radial ~;
paddles. The cables can flex of themselves and also the flexibility oF
the tires permits further flexing of the cables, and thus also the
covering fabric, to ride over obstacles.
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The wheel-like members are connected together, and are
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attached to some farm of drive mechanism. Preferably the mounting of
the wheel members is such that tilt~ng of the axis of the axle
connecting the wheels can occur to permit lifting of one wheel relative ~`
to the other.
The invention is particularly applicable to the propulsion
of vehicles, and particularly air cushion vehicles, over water on
which there may be broken ice or ather floating obstacles.
The invention will be readily understood by the
following description of certain embodiments, by way of example, in
conjunction with the accompanying drawings, in which:-
Figure 1 is a perspective view of an arrangementhaving two wheels with pneumatic tires and chains,
Figure 2 is a cross-section on the line II-II of
figure l;
Figure 3 is a cross-section on the line III-III
of figure l;
Figure 4 is a side vie~ of an alternative form of
wheel member;
Figure 5 is a cross~section on the line V-V
; Of figure 4,
Figure 6 illustrates an alternative arrangement of
mounting a paddle-wheel assembly.
As illustrated in figures 1 and 2, a paddle wheel
structure comprises two wheels 10 and 11, having pneumatic tires 12
thereon. ~hat can be termed the inboard wheel 10 is attached via
a flange 13 to a stub shaft 19 which in turn is rotatably supported
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in a support member 15, via a bearing 16. The outboard wheel 11 is
connected to the inboard wheel lQ via a shaft 17 having flanges 18 and
~Q 19 at the ends, flange 18 connected to the inboard wheel lQ and flange
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19 connected to the outboard wheel 11, as by bolts and nuts 20 and 20a
and 21 and 21a.
Extending circumferentially around each tire 12 are
chain assemblies. ~ach chain assembly comprises a circumferential
chain 23 on each side of the tire and radially extending chains 24
connecting the circumferential chains 23. The radially extending
chains 24 are spaced around the tire. Pairs of cables 25 extending
transversely between a radial chain 24 on one wheel and an opposed
radial chain 24 on the other wheel. The ca~les 24 are attached at
each end to spaced links of the radially extending chains 24.
The pairs of cables 25 carry paddles 26 of flexible
material. A convenient form of paddle is a tube of flexible material
with the cables 2S positioned inside the tube, as illustrated in ~:
figure 3. A suitable material is rubber covered or impregnated canvas, ; -
or other forms of impregnated material.
The wheels and axle assembly, 10, 11, 17 and 18 is
rotatable, for example by an hydraulic motor 30 mounted on the support
member lS. In the embodiment illustrated in figures 1 and 2,
outboard wheel 11 is attached to the shaft 17 by nuts and bolts 21121a
such that the wheel 11 can deflect relative to the shaft 17. This
can be obtained by using long bolts and fixing the nuts, as by split
pins, so that the nuts are not completel~ tight. Similarly shaft 17
is attached via flange 18 to the wheel 10, and the wheel 10 to the
flange 18, but nuts and bolts 20/20a which are not tightened up.
This is illustrated in figure 2, the nuts 20a and 21a are screwed on
to the bolts 20 and 21 so as to leave a space between the nuts and the
flanges 18 and 19, the nuts conveniently locked in this position by
split pins 31. This enables the outbaard wheel 11 to tilt relative to
wheel 10.
Figures 4 and 5 illustrate an alternative form of wheel
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member ~hich comprises a metal disc-like member 40 having a moulded
flexjble rim 41. Circumferentially extending members extend around
each wheel member and these members, in this example, are formed from
a series of arcuate sections 42 connected by links 43. The radially
extending members 44 are of concave curved sections attached to the
links 43. The transverse cables 25 attach to the radially extending
members 44. ~ther forms of wheel members, and other forms of
circumferentially extending attachment members can be provided.
Thus, for example, in a form of wheel member as in
figures 4 and 5, attachment members for attachment of the transverse -
members 25 can be formed integrally with the rim, such as by moulding
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in members to which the ends of the members 25 can be attached.
This avoids the need for the radially extending members 44, and the
arcuate sections 42. `~
. In operation, if a paddle 26 meets an obstacle, the
cables 25 can flex. Such flexing is aided by the flexing of the tires
,~ ~ 12 or flexible rims 41. If the outboard wheel hits an obstacle, such ;
as floating ice, it can lift to some degree, while torque is still -
transmitted from the shaft 14 to shaft 17 via nuts and bolts 20/20a. `~
The paddles 26 are driven by interengagement between the tires 12 or
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rims 41, and the circumferentially extending attachment members, that
is chains 23 and 24 or member5 42 and 44.
Flexibility between shaft 17 and shaft 14 can be provided
by flexible attachment means such as bonded rubber mountings, instead ;~
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of the nuts and bolts 20/20a.
In the arrangement of figures 1 and 2, mounting member 15
has been considered as a rigidly attached member of the vehicle. In
figure ~, member 15 is pivotally attached to the structure of the
vehicle, indicated at 50. In such an arrangement, the two wheels can
be rigidly connected and can move up and down as an assembly by ~ `~
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piYctting of the member lS. ~hile the paddle wheel assembly is
shown at the rear of a vehicle in figure 6, a paddle wheel assembly
can be provided at other positions, for example one on each side of a
vehicle, at the bow or eYen projecting through the bottom of a vehicle.
To provide a predetermined "stiffness" of the paddles,
means can be provided for tensioning the cables 25. Thus, as
indicated at 45 in ~igure 5, turnbuckles can be provided. Also the
inflation pressure of tires can be varied to vary deflection of the
tires.
The cables 25 can be moulded into the paddle structure as
a unitary member instead of being in a tube and any tensioning devices
can be between the ends of the cables and the attachment points at the
~ radial members 24 or 44.
`?; A vehicle with the present invention can be amphibious
and on a hard surface the tires or rims can themselves provide
propulsion.
A vehicle can ~e steered b~ propulsion means in
accordance ~ith the present inventian. Thus, ~or example, two units
as in figures 1 and 2 can be provided with provision for relative
~0 speed variations. Alternatively, a unit can be pivotally mounted on
` a vehicle.
While the invention is applicable to the propulsion of
vehicles supported, at least to some extent, by a fluid cushion, the
invention is applicable to other forms of water borne vehicle and to
amphibious vehicles.
A vehicle can be of many forms, being completely self
contained or merely a barge or even a flat platform or raft, with a
power supply to drive the wheel-like members.
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