Trw Automotive Safety Systems Gmbh

Zf Automotive Safety Germany Gmbh

Alexander Lammers

Guido Hirzmann

Martin Kreuzer

Volker Stegmann

Thomas Lind

Heinz Lefringhausen

Hans-Jürgen Bossler

Helga Heist

A method for introducing electric conductors into an overmolding of a steering wheel frame is provided. The electric conductors are used for heating and shielding purposes and for sensing contact on a steering wheel. In a first step, at least one cut is introduced into the overmolding using a cutting tool. In a second step, both a first layer of an electric conductor and a second layer of an electric conductor are simultaneously introduced into the cut that has been created. The first layer forms both a heating layer for heating the steering wheel and a guard layer which, together with the second layer acting as a sensor layer, allows the capacitive sensing of hand contact.

Method and tool for introducing electric conductors into an overmoulding of a steering wheel frame

An apparatus for heating a steering wheel and for detecting a steering wheel contact comprises a steering wheel armature () made from electrically conductive material and an electric heating conductor () arranged outside of the steering wheel armature (). The apparatus further comprises a control and evaluation device () connected to the steering wheel armature () and the electric heating conductor () by means of which control and evaluation device the electric heating conductor () is repeatedly operated temporarily during a heating operation as a heating element for heating the steering wheel and temporarily during a measuring operation as a sensor element for detecting a steering wheel contact. The control and evaluation device () is configured so as to maintain the steering wheel armature () on a predetermined and especially constant potential at least during each measuring operation.

Apparatus and method for heating a steering wheel and for sensing contact with the steering wheel

A method of introducing an electric conductor (), especially a heating wire, into foam padding () of a steering wheel skeleton () includes introducing at least one cut () into the foam padding () by means of a cutting tool (). At the same time the conductor is introduced into the produced cut (). Moreover a tool as well as a tool assembly for implementing the method and a vehicle steering wheel are provided.

Method, tool, and tool assembly for introducing an electrical conductor into a foam cladding of a steering wheel frame, and vehicle steering wheel

A device for detecting steering wheel contact comprises at least a first electrode () which is provided in a steering wheel () and which forms, together with a human body acting as a second electrode and a dielectric situated therebetween, at least one sensor capacitor (). The device also comprises an evaluation circuit () having a reference capacitor () of known capacitance which can be connected parallel to the sensor capacitor (), a direct current voltage source () which can be connected to the reference capacitor (), and a measuring device for measuring the voltage at the reference capacitor (). A method for detecting steering wheel contact using such a device comprises the following successive steps: charging the reference capacitor () by applying a known reference voltage, or charging the reference capacitor () and subsequently measuring a first voltage at the reference capacitor (); connecting, in parallel, the sensor capacitor () to the reference capacitor () so that a portion of the charge of the reference capacitor () is transmitted to the sensor capacitor (); measuring a second voltage at the reference capacitor (); end determining the capacitance of the sensor capacitor () from the known capacitance of the reference capacitor (), the reference voltage or the first voltage and the second voltage.

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Mühltal, Germany

Alexander Lammers