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by manual operation of the gear selector lever requires OPERATION OF SERVO DEVICES FOR DRIVING the driver to remove his hand from the wheel. A MOTOR VEHICLE - CONTROL, „T„ „ , A „„, ^TrT, TXTT
ARRANGEMENT AND METHOD SUMMARY OF THE INVENTION
5 The object of the invention is to improve and simplify
The present invention relates to a motor vehicle con- the control functions available to the driver, mainly
trol device, a vehicle control arrangement incorporat- those required to operate the engine and gearbox, by
ing said device, and a vehicle control method based on providing him with a readily accessible and ergonomi
said arrangement. More specifically, the control device, cally designed control device affording control of those
arrangement and method are intended preferably for 10 operating systems necessary for driving the vehicle,
motor vehicles fitted with a steering wheel, in which Combining the accelerator and gear-change controls
the control device is mounted on the steering wheel in one and the same unit, using different thumb grips to
such as to be accessible for manual operation by the operate each, and mounting the control on the steering
driver and in which the control device controls the wheel, affords a control system which is extremely
operation of both the accelerator and gear change func- 15 practical for long-distance driving, and which does not
tions in a simple and safe manner to promote safe and require the driver to release his grip on the steering
economical driving. wheel to operate the control, or to move one or both of
his feet from pedal to pedal.
In accordance with the present invention, the control
Numerous methods of operating the accelerator, 20 is mounted on the steering wheel of the motor vehicle
gearbox and brakes of motor vehicles are known. A foot such as to be manually operable by one of the driver's
pedal is the commonest means of operating the acceler- fingers while the driver's hand maintains its grip on the
ator in a car, truck or bus powered by an internal com- steering wheel. A first signal generating means, respon
bustion engine, regardless of whether the engine drives sive to manual operation by the driver's finger, is pro
the wheels through a manual gearbox or automatic 25 vided for transmitting a first control signal to a first
transmission. In some instances, this control may be servo device to control acceleration of the motor vehi
augmented by means of maintaining a constant road cle. A second signal generating means, responsive to
speed, in the form of a 'cruise control' (CC) function, manual operation by the driver's finger, is provided for
usually operated by a lever mounted on the steering transmitting a second control signal to a second servo
column. When activated by manual operation of the 30 device to initiate changing of gears in the vehicle's
lever, the function controls the throttle in such manner transmission.
that it strives to maintain the speed of the vehicle con- An arrangement for controlling a motor vehicle in
stant at the value prevailing at the instant of operation. accordance with the present invention includes first and
In some instances, the cruise control lever may also second servo devices for respectively controlling oper
incorporate throttle control functions for decelerating 35 ation of the throttle and the gear box of the motor vehi
or accelerating the vehicle. Deceleration is achieved by cle. An operating unit is mounted on the steering wheel
abrupt closure of the throttle and acceleration by abrupt such as to be manually operable by one of the driver's
opening of the throttle to a predetermined, constant fingers while the driver's hand maintains its grip on the
position. steering wheel. The operating unit includes first and
Manual accelerator controls mounted on or integral 40 second pressure sensors operable respectively in re
with the steering wheel have been used in motor vehi- sponse to pressure from the driver's finger representing
cles modified for handicapped persons mainly to meet a change in acceleration to generate a first electrical
the requirements of drivers whose legs are paralyzed. signal, and in response to pressure of the driver's finger
Examples of controls mounted on the steering wheel representing a change of gears to generate a second
are disclosed in Patent Applications DE,A,2841786 and 45 electrical signal. Control means responsive to the first
EP,A,-69090. electrical signal actuate a first servo device to control
A brake control function can also be incorporated in acceleration of the engine. In response to the second
this type of accelerator control in vehicles modified for electrical signal, the control means actuates the second
handicap persons, as disclosed in Patent Application servo device to control operation of the gear box to
EP,A,200769 and U.S. Pat. No. 4,496,018. 50 initiate and execute gear changes.
U.S. Pat. No. 4,077,487 discloses a variant with a A method for controlling a motor vehicle in accor
secondary manual brake control, mounted on the steer- dance with the present invention in which the motor
ing wheel and permitting manual operation of the vehicle includes an arrangement as discussed in the
brakes. previous paragraph, and wherein the operating unit
Many of the controls devised to date have necessi- 55 includes first, second, third and fourth finger grips for
tated control actions involving large movements, re- generating electrical signals proportionate to the
quiring the use of the complete arm or foot, or have amount of pressure applied thereto, includes the steps of
failed to take account of all of the control actions need operating the first finger grip to produce an increase in
to ensure that the vehicle is driven in a controlled man- acceleration, operating the second finger grip to pro
ner. 60 duce a decrease in acceleration, operating the third
In general, wheel-mounted brake and/or accelerator finger grip to cause upward gear changes in the gear
controls, as used primarily in vehicles modified for box in a number of individual steps and operating the
handicapped persons, have been installed in vehicles fourth finger grip to produce downward gear changes
with automatic transmissions. In this context, automatic in a number of individual steps.
transmissions suffer from the inherent disadvantage that 65 Mounting the control on a steering wheel spoke im
a gear change initiated by the driver by means of the mediately adjacent to the rim enables the accelerator
kickdown function takes place only when the engine and brake functions to be operated by a single thumb
speed has increased. On the other hand, changing gear action, using a separate and distinct thumb grip for each
