Seat belt status monitoring system

A seat belt status monitor for use with a vehicle seat belt assembly having a seat belt buckle and tongue that can be inserted and removed from the seat belt buckle, the seat belt status monitor comprising:

• a mechanical sensing member located within the seat belt buckle, said mechanical sensing member being movable within the seat belt buckle during insertion of the tongue;
• a piezoelectric element positioned relative to said mechanical sensing member such that movement of said mechanical sensing member imparts a mechanical force onto said piezoelectric element, wherein said piezoelectric element produces an electrical signal in response to the mechanical force;
• and
• a transmitter located within the buckle and connected to said piezoelectric element, wherein said transmitter emits a wireless signal in response to and powered by said electrical signal;
• wherein said mechanical sensing member is a flexible arm supporting said piezoelectric element, with said flexible arm bending during insertion of the tongue into the seat belt buckle to thereby impart the mechanical force to said piezoelectric element.

A seat belt status monitor for use with a vehicle seat belt assembly having a seat belt buckle and tongue that can be inserted and removed from the seat belt buckle, the seat belt status monitor comprising:

• a mechanical sensing member located within the seat belt buckle, said mechanical sensing member being movable within the seat belt buckle during insertion of the tongue;
• a piezoelectric element positioned relative to said mechanical sensing member such that movement of said mechanical sensing member imparts a mechanical force onto said piezoelectric element, wherein said piezoelectric element produces an electrical signal in response to the mechanical force;
• a transmitter located within the buckle and connected to said piezoelectric element, wherein said transmitter emits a wireless signal in response to and powered by said electrical signal;
• and
• a sliding element that contacts a portion of the tongue during insertion of the tongue into said opening, wherein said sliding element includes an actuating member having first and second angled surfaces located relative to said mechanical sensing member such that initial movement of said sliding element in response to insertion of the tongue causes the first angled surface to depress said mechanical sensing member, and subsequent movement of the sliding element in response to further insertion of the tongue causes the second angled surface to release said mechanical sensing member.

A vehicle seat belt buckle for use with a seat belt tongue that is insertable and removable from the seat belt buckle, comprising:

• a housing having an opening sized to receive the tongue;
• and
• a seat belt status monitor located within said housing and having a transmitter, piezoelectric element, and a displaceable component positioned within said housing such that said displaceable component undergoes movement during insertion of the tongue into said opening;
• wherein said piezoelectric element is positioned relative to said displaceable component such that movement of said displaceable component imparts a mechanical force onto said piezoelectric element during partial insertion of the tongue into said housing and then removes the mechanical force from said piezoelectric element as the tongue becomes fully inserted into said housing;
• and
• wherein, in response to the mechanical force, said piezoelectric element provides an electrical signal that is used to power said transmitter to generate a wireless seat belt status signal.

A vehicle seat belt buckle for use with a seat belt tongue that is insertable and removable from the seat belt buckle, comprising:

• a housing having an opening sized to receive the tongue;
• and
• a seat belt status monitor located within said housing and having a transmitter, mechanical sensing member, and a sliding element positioned within said housing such that the tongue engages and moves said sliding element during insertion of the tongue into said opening, with said sliding element providing a mechanical input to said transmitter via said mechanical sensing member as said sliding element moves during insertion of the tongue into said opening;
• wherein said sliding element includes an actuating member having first and second angled surfaces located relative to said mechanical sensing member such that initial movement of said sliding element in response to insertion of the tongue causes the first angled surface to depress said mechanical sensing member, and subsequent movement of the sliding element in response to further insertion of the tongue causes the second angled surface to release said mechanical sensing member;
• and
• wherein said status monitor is responsive to the mechanical input to generate a wireless seat belt status signal using said transmitter powered by said mechanical input.

A seat belt status monitoring system for monitoring the status of a plurality of vehicle seat belt assemblies within a vehicle, said system comprising:

• a plurality of status monitors, each of which is associated with a different one of the vehicle seat belt assemblies, each of said status monitors including a power source, a mechanical sensing member, a switch, and a transmitter connected to said switch and said power source, wherein each of said mechanical sensing members is mechanically connected to its associated power source and is movable such that said mechanical sensing member engages said power source and causes said power source to supply operating power to its associated transmitter during latching and unlatching of its associated seat belt assembly, each said switch being positioned to detect the latch condition of its associated seat belt assembly such that said switch is in a first state when the seat belt assembly is in a latched condition and is in a second state when the seat belt assembly is in an unlatched condition, and wherein each of said transmitters is operable in response to the state of said switch to utilize the operating power to emit a wireless signal identifying the latch condition of its associated seat belt assembly and uniquely identifying its associated seat belt assembly from the one or more other seat belt assemblies;
• and
• a receiver capable of detecting the wireless signal and determining which of the seat belt assemblies is associated with the received wireless signal.