Machine element or mechanism – Control lever and linkage systems – Foot operated
Reexamination Certificate
2001-02-09
2002-09-24
Luong, Vinh T. (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Foot operated
C074S513000, C074S560000, C267S275000, C192S08100C
Reexamination Certificate
active
06453768
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a pedal, in particular for a motor vehicle, having a pedal arm which can be deflected at its first end region by a force, in particular a foot force, is mounted at its second end region in a manner such that it can pivot about a pivot spindle mounted in a housing, and is acted upon in a manner such that it can be pivoted back into an initial position by a restoring spring element which surrounds the pivot spindle, the restoring spring element being supported on a first lever arm of a pivotably mounted lever whose second lever arm bears via a friction body against a friction surface which can be pivoted about the pivot spindle and is arranged on the second end region of the pedal arm.
Pedals of the abovementioned type are nowadays frequently used as gas pedals in motor vehicles for controlling the speed. In this case, during operation of the motor vehicle the driver of the motor vehicle deflects the pedal arm of the pedal by means of a foot force in order to reach a certain speed of the motor vehicle. In this arrangement, the deflection of the pedal arm is usually coupled mechanically or electronically to a control unit via which the speed of the motor vehicle can be set. The following generally applies: the greater the deflection of the pedal arm, the greater the speed of the motor vehicle.
During operation of the motor vehicle uneven road conditions may result in joltings of the vehicle movement and therefore in slight changes to the foot force applied to the pedal arm by the driver. These jottings of the vehicle movement may cause a change in the pedal position, which results in a change in the speed of the motor vehicle.
In order to prevent an unintentional change in the pedal position by the driver of the motor vehicle, the pedal arm of the pedal is supported on the first lever arm of the pivotably mounted lever by means of the restoring spring element surrounding the pivot spindle. When the pedal arm is deflected, the restoring spring element deflects the first lever arm of the lever and at the same time the second lever arm of the lever pivots in the direction of the second end region of the pedal. From a certain angle of deflection of the pedal arm onward there occurs contact between the friction body, which is arranged on the second lever arm, and the friction surface which is arranged on the second end region of the pedal arm. The frictional force acting between the friction body and the friction surface inhibits the foot force which deflects the pedal arm. In this arrangement, the spring action of the restoring spring element causes, with increasing deflection of the pedal arm, an increase in the frictional force between the friction body and the friction surface, and a self-starting vibration, the so called frictional vibration, occurs. The frictional vibration is caused by the difference between the relatively large frictional force when running on occurs, i.e. when there is contact between the friction body and the friction surface, and the relatively small frictional force during the subsequent sliding movement. The frictional vibration occurs in particular at very small sliding speeds and is a nuisance because it causes jerky sliding. This effect, which is also known as the “stick-slip effect”, can be perceived clearly by the people in the interior of the vehicle as a squealing noise during operation of the pedal.
In order to suppress this squealing noise it is known, for example from DE 198 11 442 A1, to connect the friction body to the second lever arm of the pivotably mounted lever via a vibration damper. This causes the friction body to be decoupled mechanically from the second lever arm of the lever, as a result of which the friction body can vibrate freely relative to the second lever arm of the lever. The friction surface is usually formed integrally with the pedal arm and therefore cannot vibrate. The squealing noise is therefore reliably avoided by means of the friction damper additionally arranged on the second lever arm of the pivotably mounted lever. A disadvantage of this solution is the fact that the friction surface always consists of the material from which the pedal arm or at least the second end region of the pedal arm is also manufactured. This means that the design of the friction pairing formed by the friction body and the friction surface is determined only by a suitable selection of the friction body. This is because the contribution of the friction surface to the friction pairing is predetermined by the material of the pedal arm and is not a variable parameter of the friction pairing. In order to bring about a change in the friction pairing by the friction surface, the pedal arm would have to be manufactured from a different material than the previous material, which generally has a disadvantageous effect on the production costs and on the outlay on production of the pedal arm and is therefore not usual in practice.
SUMMARY OF THE INVENTION
The invention is therefore based on the object of specifying a pedal of the abovementioned type which requires a particularly low outlay on production and in which the coefficient of friction of the friction pairing formed from the friction body and the friction surface can be set within a particularly large range of values.
According to the invention, this object is achieved in that the friction surface is part of a friction element, and the second end region of the pedal arm is connected fixedly to the friction element via an adhesive material.
The invention proceeds from the consideration that a pedal which is to be produced in a particularly simple manner and is to be fitted in a particularly simple manner should have a particularly small number of elements which can be fitted together during the final installation of the pedal. However, both the material of the friction body and the material of the friction surface should be freely selectable so as to provide a particularly large range of values for the coefficient of friction of the friction pairing. This condition is met for the friction body, which can be fastened via the vibration damper to the second lever arm of the pivotably mounted lever during installation of the pedal. The material of the friction surface can be selected freely if the latter is not part of the second end region of the pedal arm. The friction surface is not part of the pedal arm if it is arranged separately on a friction element. The friction element which contains the friction surface can in turn—like the friction surface up to now—be arranged on the second end region of the pedal arm. However, a friction element designed in two pieces with the second end region of the pedal arm may be caused to vibrate and in an extreme case may become detached from the second end region of the pedal arm. These vibrations also cause noises. In order to avoid such malfunctions and noises of the pedal, the second end region of the pedal arm should be connected particularly firmly to the friction element without the outlay on production of the pedal being increased because of an additional element. For this purpose, the second end region of the pedal arm is connected fixedly to the friction element via an adhesive material. In this case, the adhesive material may be a glue, for example a commercially available glue, or else a firm synthetic material which undergoes a virtually nondetachable connection both with the second end region of the pedal arm and with the friction element.
The adhesive material is advantageously designed as a film which bonds on both sides. A self-adhesive film produces a homogeneous bonding surface and can be cut precisely into shape. In addition, before the friction element which contains the friction surface is fastened on the second end region of the pedal arm, a film can be fastened either on the underside of the friction element or on the second end region of the pedal arm, with the result that for the final installation the surfaces which are to be connected just need to be pressed on to one anot
Kohlen Peter
Wehner Andreas
Weis Christian
Farber Martin A.
Luong Vinh T.
Mannesmann VDO AG
LandOfFree
Pedal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pedal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pedal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2856290