Rotation sensor

A rotation sensor comprising:

• first and second rotors individually attached to first and second rotary shafts so as to be rotatable in unison therewith, the first and second rotary shafts being coupled through a torsion bar that allows a rotational difference between the first and second rotary shafts;
• a base plate rotatable in unison with said first rotor;
• first and second electrical resistors individually formed on first and second faces of said base plate so as to extend in a rotating direction of said base plate;
• a first holder fixedly disposed on a side of the first face of said base plate;
• a second holder disposed on a side of the second face of said base plate so as to be rotatable in unison with said second rotor;
• a first contact member fixed at its one end portion to said first holder and provided at another end portion with a contact, said first contact member having an arm portion thereof extending between these end portions, rotation of said base plate causing relative sliding motion between the contact and said first electrical resistor, with the contact being in electrical contact with said first electrical resistor;
• and
• a second contact member fixed at its one end portion to said second holder, said second contact member having another end portion thereof provided with a contact and an arm portion thereof extending between the end portions of said second contact member, rotation of said base plate causing relative sliding motion between the contact and said second electrical resistor, accompanied with a rotational difference between the said base plate and said second holder, with the contact being in electrical contact with said second electrical resistor,
• wherein an angle of rotation of said first rotor, caused by the relative sliding motion between the contact of said first contact member and said first electrical resistor, is taken out from said first contact member in a form of electrical signal,
• an angle of rotation of said second rotor, caused by the relative sliding motion between the contact of said second contact member and said second electrical resistor, is taken out from said second contact member in a form of electrical signal, and
• the arm portion of at least one of said first and second contact members has asymmetric widthwise weight distribution about a longitudinal axis of the arm portion.