Adjusting mechanism for a control member

An adjusting mechanism for a control member for influencing automotive vehicle engine torques. A spring-supported actuating member is articulated via pulleys at a mechanical linkage. The mechanical linkage transmits the movement of the actuating member onto a control member. The control member is influenced irrespective of the activation of the actuating member by another control variable effective, in particular, by the slip effect of driven vehicle wheels. A functionally optimized mechanical linkage is provided which has no reactive effect on the actuating member. This linkage comprises a first cable connecting link and a second cable connecting link, with the second mechanical connecting link cooperating with the control member via a pair of pulleys which are arranged on a lever and partially wrapped by the second cable connecting link.

TECHNICAL FIELD 
The present invention relates to an adjusting mechanism for a control 
member, in particular, for influencing automotive vehicle engine torques. 
BACKGROUND ART 
A similar adjusting mechanism is already known from DE-OS 36 28 456. In 
this adjusting mechanism, the mechanical link is composed of a Bowden 
cable with a toothed belt integrated by sectors and guided between a 
deflection pulley, an input wheel and a set wheel. An electromagnetically 
excited adjusting means adjusts the set wheel so that the effective length 
varies by the variation of the toothed belt deflection, whereby the 
length-variable adjustment of the mechanical link causes modification of 
the throttle valve aperture angle in dependence on the pedal position. 
A disadvantage of this arrangement is that during traction slip control the 
reactive effect of the control action on the pedal cannot be totally 
prevented. Furthermore, a particular shortcoming of this arrangement is 
that, while taking into consideration a simple and functionally reliable 
design with increasing number of interposed guide wheels and set wheels 
used, there is a considerable increase in fatigue under reversed bending 
stresses, in particular when wire ropes are used, as well as an increase 
in losses due to friction and an augmented tendency of the wheels to 
clamp. 
SUMMARY OF THE INVENTION 
Hence, it is an object of this invention to devise an adjusting mechanism 
which ensures a functionally optimized as well as deceleration-minimized 
control, while low-cost and simple individual component parts are used and 
the above-mentioned shortcomings are eliminated. 
Thus, an adjusting mechanism is provided which during traction slip control 
and/or engine stall torque control prevents reaction on the pedal in a 
simple fashion and, at the same time, provides for an almost unimpaired 
response behavior for the purpose of attaining a decelerationless control. 
A preferred embodiment of the present invention has the deflection pulley 
arranged to be pivoted in the lever so that during the tilting movement of 
the lever no relative movement affected with friction has to be 
transmitted between the second connecting link and the deflection pulley. 
As a result, there remains merely a small-surface bearing area on the axis 
of rotation of the deflection pulley which surface is minimized in respect 
of friction. 
In order to reduce the necessary space requirement, the present invention 
has the torsion spring arranged as a spiral spring which is attached 
between the lever and the regulator pulley. 
Further features, advantages and possible application of the present 
invention can be gathered from the following description of a preferred 
embodiment.

DETAILED DESCRIPTION OF THE INVENTION 
The drawing shows, in a schematic sketch, the inventive adjusting mechanism 
composed of a connecting link 3 and a second mechanical connecting link 4 
which permit a mechanical transmission between an actuating member 2 and a 
control member 1 indirectly through a lever 5 with a regulator pulley 10 
and a deflection pulley 8. Both the regulator pulley 10 and an 
intermediate member 12 associated with the control member 1 are acted upon 
by spring force. 
In the event of manual activation of the actuating member 2 which normally 
is the accelerator pedal, the actuating member swivels around its 
stationary point of support and transmits this movement onto the first 
deflectable and flexible connecting link 3 which is articulated at the 
actuating member 2 and is preferably designed as a Bowden cable. In 
consequence thereof, under the effect of tensile force of the first 
mechanical connecting link 3, the lever 5, too, swivels about its 
stationary axis of rotation 6 to the right in the drawing. The axis of 
rotation 5 arranged in the area of the a torsion spring 9, preferably in 
the form of a spiral spring. This deflection of the lever 5 is followed by 
a deflection in the same direction of the second connecting link 4 which 
is guided on the lever 5 via deflection pulley 8 so that the intermediate 
member 12 fastened to the second connecting link 4 performs a synchronous 
movement in the same direction. To accomplish tightening and resetting of 
the second connecting link 4, which is preferably designed as a Bowden 
cable, in consequence of the release of the accelerator pedal, the end of 
the second Bowden cable which is connected to the intermediate member 12 
is biased by means of a tension spring 13. The opposed second end of cable 
4 is fixed at the regulator pulley 10. The minimum force of the torsion 
spring 9 is at least as large as, and oppositely directed to, the maximum 
tension force of the tension spring 13. The regulator pulley 10 is kept in 
its inactive position on its stop 11 by the action of the torsion spring 9 
that is attached to the regulator pulley 10 and the lever 5. 
Flexible connecting links 3 and 4 may be steel wire or stranded nylon wire. 
Upon commencement of the traction slip control operation, a preferably 
electronically controlled servo motor, which is not shown in the drawing, 
ensures that the adjusting movement of the accelerator pedal is 
superimposed by the twisting of the regulator pulley 10 on the lever 5 so 
that there is effected a change in the throttle valve aperture angle and 
hence an intervention without reaction on the accelerator pedal and 
superimposed on the introduced manual movement, what results in 
influencing the engine torque governed by way of the accelerator pedal.