Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21153i7
ZERO G SUSPENSION
The present invention relates to a device for supporting the weight
of a land vehicle above ground level. Such devices are commonly called
suspension systems.
Various types of suspension systems are known. One type comprises
of wheels attached directly to the vehicle body by means of various
configurations of supporting arms. The force necessary to keep the vehicle
above ground level is supplied by various types of springs which are
attached at one end to the supporting arms or directly to the wheels, and
at the other end the springs are attached directly to the vehicle body.
Because the vehicle body is supported by these suspension systems at a
point which lies bellow their centre of gravity, when moving in a turn
these vehicles are subject to a rolling moment to the outside of the turn.
This causes a sensation of discomfort to the passengers of the vehicle.
Some types of suspension systems attempt to correct this problem by
employing shock absorbers which have a high resistance to the forces
which cause the vehicle to roll. The disadvantage of these suspension types
is that they cause strong jarring movements of the vehicle when it is
passing over bad pavement. Still other types of suspension systems limit
the rolling moment of the vehicle by employing sophisticated pneumatic
springs which can vary the force they apply to the wheels to counteract
the rolling moment of the vehicle when necessary -i.e. in a turn-. Their
disadvantage is that they are complex, expensive and heavy.
It is des*able to have a suspension system that can allow the vehicle
body to tilt towards the radius of the turn, in order to neutralise the lateral
accelerations acting on the vehicle body when the vehicle is moving in a
turn. It is desirable that the suspension system be simple and inexpensive.
The present document relates to a suspension system for modifying
the rolling moments acting on a vehicle body when the vehicle is moving
in a turn. As used in this description and in the appended claims, the word
"collinear" means lying on the same straight, real or im~in~ry line.
In one aspect of the invention the suspension comprises a set of sub
frames. The number of sub frames to be used depends on the number of
transversal axles of the vehicle. For example, a four wheeled vehicle will
preferably have two sub frames, one for the two front wheels and one for
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the two rear wheels. The wheels are linked to the sub frame by means of
any suitable arrangement of arms and links. The devices used to provide
the force necessary to support the weight of the vehicle above ground
level (i.e. springs) exert their lifting force between the wheels and the sub
frame. (The springs do not exert their force directly on the car body?
include? yes/no. describe further later). The weight of the vehicle is
supported by the sub frames at a point or at a set of collinear points which
lie on the same imAginary longitudinal axis of the vehicle, at the same level
as or preferably above the level of the centre of gravity of the vehicle. At
the point of support, the vehicle body is allowed to turn about a
longitudinal axis with respect to the sub frames. However, at the point of
support the rotation of the vehicle body with respect to the sub frames
may be arrested by means a jAmming device. The jamming device may be
activated at the wish of the vehicle passengers, if they should prefer that
the vehicle roll to the outside of the turn instead of the inside. During
normal operation of the suspension system, while the vehicle is moving in
a turn, the car body is allowed to tilt to the inside of the turn, i.e. with
the edge of the vehicle body closer to the centre of the turn downwards
and with the vehicle edge that is farther from the centre of the turn
upwards .
The resulting tilt will reduce the effect of the lateral accelerations on
the vehicle body. Instead, the lateral accelerations will be directed
downwards, with respect to the vehicle body.
In another aspect of the invention the suspension system consists of
a set of sub frames. Each sub frame has an approximately "U" shape, as
viewed from the wheels. The wheels are linked with a suitable
arrangement of arms to the two vertical arms of the sub frame. Each
wheel should have a set of arms linking it to each of the two vertical arms
of the sub frame. The arms linking the wheels to the sub frame should
allow the wheels to move up and down to follow road irregularities. The
device supplying the force required to support the weight of the car is
exerting that force between the sub frame and the wheels. Alternatively
the force required to keep the vehicle body above the ground may be
applied between the sub frame and the the suspension arms. Alternatively
the force required to keep the vehicle body above the ground level may be
applied between the suspension arms. The exact points of application of
the force required to lift the vehicle body are not required to be in any
specific location, however the points of application should NOT be placed
directly on the vehicle body. The weight of the vehicle body is supported
by the sub frames at collinear set of points on an imaginary longitudinal
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axis of the vehicle body, above the centre of gravity of the vehicle. At the
point of support the vehicle should be allowed to rotate with respect to the
sub frames. The sub frames should be inflexible and made of any suitable
material, such as steel, aluminium, carbon fibres, etc. The embodiment
described is particularly suitable for vehicles having a front engine and a
front wheel drive system.
In a further embodiment of the invention the suspension system
comprises of two sub frames, one for the front wheels and one for the rear
wheels. Each sub frame should approxim~tely resemble a square frame
with four vertical legs extending vertically upwards from each of the four
corners of the square frame. The four legs may be parallel or non-parallel
to each other. The four legs may be perpendicular or non-perpendicular to
the plane of the square frame. These particulars must be decided upon
depending on the design requirements or philosophies. The four sub frame
legs should be arranged two on each side of the longitudinal axis of the
vehicle. The wheels are attached to the sub frame by means of any
combination of suspension arms, links, etc. depending on design. Each
wheel should have a suitably arranged set of suspension arms linking each
one of them to two of the sub frame vertical suspension legs. Each wheel
should be linked to two separate sub frame legs. The two vertical sub
frame legs to which a wheel is attached should be on the same side of the
longitudinal axis of the vehicle. The device supplying the force required to
lift the vehicle body should apply that force between the sub frame and
any other suspension element not connected directly to the vehicle body.
The weight of the vehicle body is supported by the sub frames at a set of
points which lie on an im~ginary longitudinal support axis. For that
purpose, the sub frames should have an extra set of support legs, rigid
with respect to the sub fr~me, to support the vehicle body. The extra set of
support legs can be suitably shaped to be as rigid as possible, while
allowing space for the placement of the engine and other internal
components of the car. The im~in~ry longitudinal support axis should be
placed directly above the centre of gravity of the vehicle. At the point of
support, the vehicle is normally allowed to turn about the imaginary
longitudinal axis with respect to the sub frames, such that when moving in
a turn the vehicle is allowed to tilt in the direction of the turn, i.e. with the
edge of the vehicle closer to the centre of the turn downwards. If so
desired by the passengers of the vehicle, the tilting motion of the vehicle
body toward the centre of the turn of the turn can be transformed into a
tilting motion away from the centre of the turn by means of a j~mming
device suitably designed to stop the rotation movement of the vehicle
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body with respect to the sub frames.
Referring to the drawings, a further embodiment of the
invention consists of a sub frame 8. Sections 24, 26, 28, 30, 32, 34, 36 and
38 are all part of the sub frame 8. Those sections are rigid with respect to
each other. They have been numbered separately to insure the knowledge
that they are rigid with respect to each other. The suspension arms 42, 52,
44, 54, 48, 46, 50, 82, are connected at one end to a wheel axle support
assembly and at the other end to the suspension sub frame 8. The wheel
axle support assemblies comprise of the arms 56, 58, 72, 70 and 60, 74, 76,
and 62 respectively. These elements are preferably rigid to one another.
The wheel axles 2 are connected to the wheel axle support assemblies. The
method of connection of the wheel axles to the wheel axle support
assemblies should allow the wheels to rotate along their vertical axis to
turn the car. At all points of contact between the arms and sub frame or
between the sub frame and the wheel axle support assemblies, vertical
movement should be allowed, so that the wheels can follow road
irregularities. The force required to keep the vehicle body above the
ground can be provided by any suitable devices 40. Those devices act
between the sub frame 8 through an element 80 and the suspension arms
44 and 54. The vehicle body weight is supported at the points of of
support 12. The entire suspension system comprises of more than one sub
frame. The points of support 12 of all the suspension sub frames should lie
on the same longitudinal axis 20. The axis 22 represents the axis on which
the centre of gravity of the vehicle body lies. The axis 22, containing the
centre of gravity of the vehicle, should be positioned bellow the axis 20
containing the points of support and NOT above it. The suspension sub
frame 8 and the vehicle body are normally free to rotate with respect to
each other around the points of support 12. A braking device can be
installed at the point of rotation to stop the rotation if the passengers
desire that the vehicle should roll to the outside of the turn rather than the
inside. This particular embodiment is more suitable to vehicles with front
engines and front wheel drive systems.
Although only two embodiments of the present invention have been
described and only one illustrated, the present invention is not limited to
the features of these embodiments, but includes all variations and
modifications within the scope of the claims.
