Note: Descriptions are shown in the official language in which they were submitted.
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Wheel Controller for an Aircraft
The present invention relates to a wheel controller for an aircraft, in
particular air-
plane, by means of which at least one wheel, in particular nose wheel, can be
con-
trolled, and wherein the wheel controller preferably is a nose wheel
controller or
tiller, and to an aircraft, in particular airplane, with at least one wheel
controller.
The nose wheel controller, also referred to as tiller, is utilized to steer an
airplane at
low velocities at the ground. For example, the pilot of the airplane utilizes
the nose
wheel controller, in order to steer the airplane from the parking space to the
take-off
runway and on to the beginning of the take-off operation, when the rudder does
not
yet have an aerodynamic effect and a change in direction of the airplane can
not
yet be accomplished by actuating the rudder.
Modern nose wheel controllers are designed as steer-by-wire systems, which
means that the rotary movement present at the hand wheel of the nose wheel con-
troller is detected by means of sensors and converted into an electrical
signal. This
electrical signal in turn is evaluated by an electronic system and thus
effects a de-
flection of the nose landing gear of the airplane.
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Known nose wheel controllers in addition include resetting systems by means of
which the nose wheel can be reset into the zero-degree position, i.e. usually
the
position for driving straight ahead.
In this connection, for example, a self-centering nose wheel control system is
known from DE 602 24 108 T2, in which by means of an eccentrically arranged
tor-
sion spring the nose wheel controller can automatically be reset into a zero-
degree
position, when no more steering torque is present.
From US 2008/0011905 A1 there is furthermore known a side-stick system for con-
trolling the airplane both at the ground and in the air, which likewise is
provided with
a resetting system. This resetting system effects that in case of missing
actuation,
the side stick is reset into an upright reference position.
It would be desirable, however, to increase the reliability of a nose wheel
controller
and in general provide for an improved operability with a simpler construction
of a
nose wheel controller at the same time.
Therefore, it is the object of the present invention to develop a wheel
controller for
an aircraft as mentioned above in an advantageous way, in particular to the
effect
that the reliability of a wheel controller is increased and furthermore
preferably to
provide for an automatic reset and safe actuation of the wheel controller even
in the
case of a failure of components of the wheel controller.
According to one aspect of the invention, there is provided a wheel controller
(10)
for an aircraft, for controlling at least one wheel, the wheel controller (10)
including:
at least one resetting means (30) for resetting the wheel controller (10) to a
cen-
tered zero position. wherein the resetting means (30) includes at least two
spring
means (32), each of which acts independently of each other, to effect a reset
of the
wheel controller to the centered zero position; at least two sensor means
(40), each
of which acts independently of each other, for detecting a steering movement
and
generating corresponding elec-tronic signals; at least two switch means (70),
each
of which acts indepenedently of each other, for activating the wheel
controller (10);
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and at least two compression spring means (60, 62), each of which acts inde-
penedently of each other, for resetting an actuating means (50); wherein the
switch
means (70) is actuated by the actuating means (50).
Accordingly, it is provided that a wheel controller for an aircraft, in
particular air-
plane, by means of which at least one wheel, in particular nose wheel, can be
con-
trolled, and wherein the wheel controller preferably is a nose wheel
controller or a
tiller, includes at least one resetting means by means of which the wheel
controller
can be reset into a centered zero position, wherein the resetting means
includes at
least two spring means by means of which a reset of the wheel controller into
the
centered zero position each can be effected independent
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of each other, and/or includes at least two sensor means by means of which
elec-
tronic signals each can be generated independent of each other for deflecting
the
wheel in dependence on the steering movement, and/or includes at least two
switch
means by means of which the wheel controller each can be activated independent
of each other, and/or includes at least two Compression spring means by means
of
which an actuating means each can be reset independent of each other, wherein
the switch means can be actuated by means of the actuating means.
The wheel controller advantageously is a steer-by-wire wheel controller by
means
of which for example the nose wheel of an airplane can be controlled.
This involves the advantage that due to a redundant construction as regards
the
essential components of the wheel controller a much higher reliability of the
wheel
controller can be achieved. For example, in a case in which a spring means of
the
resetting means fails, e.g. due to breakage, a reset of the wheel controller
into the
centered zero position nevertheless can be effected, since this can already be
ef-
fected by the other, second spring means.
Even a failure of the sensor means does not lead to the failure.of the .entire
wheel
controller, since by means of the other, second sensor means the steering move-
ments still are detected and can be converted into electronic signals for
actuating
the wheel. The sensor means for example can be a tandem sensor or comprise a
tandem sensor.
A failure of one of the switch means likewise does not lead to the failure of
the en-
tire wheel controller, since by means of the second switch means an activation
of
the wheel controller, but also a deactivation, still is possible.
Usually, an actuating means acts on the switch means, in order to activate the
wheel controller. For resetting the actuating means two compression spring
means
now are provided, which each can reset the actuating means independent of each
other. This ensures that even in case of a failure of one of the two
compression
. _
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spring means a reliable reset of the actuating means still is possible. A safe
activa-
tion or deactivation of the wheel controller can be achieved thereby.
Furthermore, a
haptic feedback advantageously is generated for the pilot by means of an
endless
spring means, which makes a pressure point noticeable in connection with the
act-
uation of the switch means for activating the wheel controller.
Furthermore, it can be provided that the wheel controller includes at least
one steer-
ing wheel or hand wheel, wherein by means of a press-in movement of the
steering
wheel or hand wheel or a part of the steering wheel or hand wheel the wheel
con-
troller can be activated and/or deactivated. It is conceivable, for example,
that the
wheel center or wheel hub and the head of the hand wheel axle or steering
wheel
axle or the hand wheel center or steering wheel center is designed to be at
least
partly depressible and the same must be depressed for activating the wheel
control-
ler. Releasing the same correspondingly leads to a deactivation of the wheel
con-
troller.
In addition, it is conceivable that the spring means of the resetting means is
and/or
comprises a leg spring installed pretensioned.
Furthermore, it is conceivable that the spring means of the resetting means
are ar-
ranged concentrically with respect to the steering axle of the steering wheel
or hand
wheel of the wheel controller.
In addition, it is possible that a damping means is provided, by means of
which the
resetting movement can be attenuated, in particular can be attenuated such
that a
roll-over over the zero point can be prevented and/or a controlled- return
into the
centered zero position can be effected. With the damping means the wheel
control-
ler thus has a further safety means, so that the operational safety of the
wheel con-
troller can further be increased. The damping means for example can be a
rotation-
al damper. A possible roll-over over the zero point thus can advantageously be
pre-
vented, so that even when releasing the steering wheel or hand wheel of the
wheel
controller, a controlled and slow movement into the centered zero position is
ef-
w- v--
v = Y.... V v=A
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fected, namely both by the steering or hand wheel and by the actuated wheel,
in
particular nose wheel.
It is furthermore possible that an endless spring means is provided, wherein
by
means of the endless spring means a haptic feedback can be generated. The end-
less spring means can be an endless spring. Preferably, a haptic feedback can
be
generated to the effect that the haptic feedback makes a pressure point
noticeable
in connection with the actuation of the switch means for activating the wheel
con-
troller. For example, it can be provided that the endless spring means is
arranged in
the lower region, in particular in the lower third of the actuating means.
In addition it can be provided that the sensor means can be driven or is
driven by
means of at least one gearwheel mounted and pretensioned on the sensor means,
wherein the gearwheel preferably meshes with a toothing on the main shaft of
the
wheel controller. Advantageously, a minimization of the gearwheel backlash be-
tween the gearwheels of the sensor and the main shaft, i.e. for example
between
the steering and hand wheel shaft, can be accomplished.
Furthermore, it can be provided that the compression spring means are arranged
concentrically with respect to the steering axle of the steering wheel or hand
wheel
of the Wheel controller. For example, it can be provided that the steering
shaft of the
steering or hand wheel is a hollow shaft in which the compression spring means
are
inserted and guided.
Furthermore, it is conceivable that the actuating means resettable by means of
the
compression spring means is a pressure tappet by means of which the switches
can be actuated, and wherein the pressure tappet is movable by a press-in move-
ment of the steering wheel or hand wheel or a part of the steering wheel or
hand
wheel of the wheel controller.
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In addition, the present invention relates to an aircraft with the features of
claim 10.
Accordingly, it is provided that an aircraft, in particular airplane, includes
at least
one wheel controller according to any of claims 1 to 9.
Further details and advantages of the invention will now be explained in
detail with
reference to an exemplary embodiment illustrated in the drawing,
in which:
Figure 1: shows a side view of the nose wheel controller;
Figure 2: shows a detailed representation of the section B-B as shown in
Figure 1
through the nose wheel controller; and
Figure 3: shows another detailed representation of the section B-B as shown in
Figure 1 through the nose wheel controller.
Figure 1 shows a side view of a nose wheel controller 10 for an aircraft, here
for an
airplane, as an exemplary embodiment of the wheel controller 10 according to
the
invention. The nose wheel controller 10 can be activated by depressing the
activa-
tion surface 22 of the hand wheel 20, wherein the activation surface 22 (cf.
Figure
2) is formed by the head of the pressure tappet 50.
The nose wheel controller 10 has a modular design and is encapsulated in a
hous-
ing 14 for the purpose of a safe and fast replaceability, which housing is
visibly
sealed off to the outside by a cover plate 12 from which the hand wheel 20 pro-
trudes and is rotatable relative to the same.
The housing 14 shown transparent allows a view to the resetting means 30,
which
comprises two leg springs 32. The leg springs 32, which are installed
pretensioned,
independently ensure a reset of the hand wheel 20 into the centered zero
position
after releasing the hand wheel. To prevent a possible roll-over over the zero
point,
, ,
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the nose wheel controller 10 is provided with at least one rotational damper
90,
which on releasing the hand wheel 20 controls the hand wheel 20 and also the
nose wheel and slowly moves the same into the centered zero position. For this
Purpose, the rotational damper 90 in particular includes a coupling wheel
which is
directly or indirectly connected with the axle of the hand wheel 20.
In principle, a rotational damper 90 already is sufficient to prevent a
possible roll-
over over the zero point. This also serves to increase the operational safety
of the
nose wheel controller 10, wherein it is possible in addition to design the
rotational
damper 90 redundant.
Figure 2 shows the section B-B as the same is indicated in Figure 2, and here
a
segment concerning the arrangement of the springs. The hand wheel 20 is con-
nected with a hollow shaft 24 in which the pressure tappet 50 is guided. On
the side
of its head, the pressure tappet 50 forms the activation surface 22 for the
nose
wheel controller 10, which is indicated by means of reference numerals.
Further-
more, two compression springs 60 and 62 are guided in the hollow shaft 24 and
arranged concentrically with respect to the axis of rotation of the steering
wheel 20.
The longitudinal axis of the pressure tappet 50 also extends concentrically
with re-
spect to the axis of rotation of the steering wheel 20. At the lower end of
the pres-
sure tappet 50, which is depressible, but is non-rotatably guided in the
hollow shaft
24, the two microswitches 70 are arranged, as is shown in Figure 3. By means
of
the pressure tappet 50 two miniature switches 70 or microswitches 70 are
actuated.
For actuating the pressure tappet 50 and hence for actuating the two miniature
switches 70 the two compression springs 60 and 62 must be compressed, wherein
the pretension of one of the two compression springs 60, 62 already is
sufficient to
move the pressure tappet 50 back into its starting position. This starting
position is
synonymous with a non-actuation of the two miniature switches 70 and hence
with
a deactivation of the nose wheel controller 10. Only by depressing the
activation
surface 22 and hence by actuating the pressure tappet 50 are the two miniature
switches 70 triggered by means of the tappets 72 of the miniature switches 70
and
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is the nose wheel controller 10 activated thereby. In principle, it is already
sufficient
when only one of the two miniature switches 70 is activated. A failure of one
of the
two miniature switches 70 thus remains without consequences. Even a breakage
of
one of the two compression springs 60, 62 remains without consequences, since
the spring force of one of the two compression springs 60, 62 already is
sufficient to
reset the pressure tappet 50 into its starting position.
A haptic feedback for the pilot advantageously is generated by means of an
endless
spring 80 arranged in the lower third of the pressure tappet 50, which makes a
pressure point noticeable in connection with the actuation of the miniature
switches
70 for activating the wheel controller 10.
Beside the receptacle of the pressure tappet 50 the two sensors 40 are
arranged,
by means of which the steering movements are detected. A deflection of the
hand
wheel 20 by the pilot, i.e. a steering movement, is detected by the two
sensors 40
which then generate corresponding electrical signals.
By means of gearwheels 42 each mounted and pretensioned on the sensor 40 a
corresponding steering movement can be detected. The signals generated thereby
in turn are evaluated by an electronic system and then effect a corresponding
def-
lection of the nose landing gear. Here as well, the failure of one of the two
sensors
40 advantageously does not lead to the failure of the nose wheel controller
10,
since the sensors 40 are designed redundant and the signal obtained by means
of
one of the two sensors 40 is sufficient to effect a deflection of the nose
landing gear
corresponding to the steering movement specified by means of the hand wheel
20.
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