Movable unit and system for sensing at least one characteristic parameter of a tyre

A movable unit for sensing at least one characteristic parameter of a tyre fitted to a vehicle, comprising:

• a device for sensing the at least one characteristic parameter;
• a device for transmitting a signal out of the tyre;
• and
• a device for generating electrical energy;
• wherein the signal relates to the at least one characteristic parameter,
• wherein the electrical energy generating device is capable of supplying electrical energy to the sensing device,
• wherein the electrical energy generating device is capable of supplying electrical energy to the transmitting device,
• wherein the electrical energy generating device comprises a capacitor, the capacitor being charged with electrical energy in response to mechanical stresses applied to the tyre, and
• wherein the capacitor comprises two plates moving with respect to each other in response to the mechanical stresses.

A vehicle wheel, comprising:

• a tyre;
• a supporting rim for the tyre;
• and
• a movable unit combined with the tyre;
• wherein the movable unit comprises:
• a device for sensing at least one characteristic parameter of the tyre;
• a device for transmitting a signal out of the tyre;
• and
• a device for generating electrical energy;
• wherein the signal relates to the at least one characteristic parameter,
• wherein the electrical energy generating device is capable of supplying electrical energy to the sensing device,
• wherein the electrical energy generating device is capable of supplying electrical energy to the transmitting device,
• wherein the electrical energy generating device comprises a capacitor that, the capacitor being charged with electrical energy in response to mechanical stresses applied to the tyre, and
• wherein the capacitor comprises two plates moving with respect to each other in response to the mechanical stresses.