A seat belt retractor including a spool and a measurement mechanism for determining a measure of the amount of seat belt webbing unwound from the spool. The measurement mechanism includes cycloidal gear transmission. A sensor is provided for detecting movement of a magnet mounted on a sensing gear and a controller may be provided for determining a measure indicating the amount of rotation of the spool and the amount of webbing withdrawal based on the movement of the magnet.

A retractor assembly includes a housing; a spool rotatably coupled to the housing and defining an axis; a webbing coiled about the spool; a disc in contact with the webbing and movable parallel to the axis; and a linear variable differential transformer including a core movable parallel to the axis with the disc.

A seatbelt assembly includes webbing elongated along a length, a clip slidable along the length of the webbing, an indicator extending along the length of the webbing, and a sensor coupled to the clip and sensitive to the indicator. The seatbelt assembly measures a length of a lap band stretched across an occupant. Safety features may be tailored to the body type of the occupant.

A system for detecting improper usage of a seatbelt of a vehicle includes a vehicle seat having a seat cushion and a seat back. A shoulder belt and a lap belt are intended to restrain an occupant sitting on the vehicle seat. The system includes a sensor module associated with the shoulder belt and the lap belt. The sensor module generates signals indicative of at least one parameter associated with the vehicle seat, the shoulder belt, and the lap belt when the occupant is sitting on the vehicle seat. The system also includes a controller that receives the signals indicative of the at least one parameter associated with the seat back, the shoulder belt, and the lap belt. The controller analyzes the received one or more signals, and determines whether the seatbelt is being used improperly by the occupant, based on the analysis.

A system includes an infrared source is configured to transmit infrared waves. The system also includes a material that reflects infrared waves. An infrared receiver is configured to receive infrared waves reflected from the material.

A seatbelt system for a vehicle comprises a webbing (28), a belt retractor, a belt reel (16) and a belt reel angle sensor (22) having a first gearwheel assembly (32) and a second gearwheel assembly (36). The belt reel angle sensor (22) includes a multi-stage gearing (58) having a first gear stage with a first reduction ratio and a second gear stage with a second reduction ratio. The belt reel angle sensor (22) further comprises a rotation angle sensor (64) and a rotation angle transmitter (34) associated with the rotation angle sensor (64) as well as a reference signal sensor (68) and a reference signal transmitter (38) associated with the reference signal sensor (68). The rotation angle transmitter (34) is associated with the first gearwheel assembly (32) and the reference signal transmitter (38) is associated with the second gearwheel assembly (36). Relative to the reference signal sensor (68), the second gearwheel assembly (36) has a parking position, a base position and a reference position at which the reference signal transmitter (38) generates a reference signal in the reference signal sensor (68). Moreover, a method for determining the webbing extension by means of such seatbelt system is described.

A system includes a first webbing payout sensor and a seatbelt wear condition module. The first webbing payout sensor can detect a first webbing payout of a seatbelt associated with a seat of a vehicle. The first webbing payout is a first length of webbing of the seatbelt dispensed from a first retractor of the seatbelt. The seatbelt wear condition module can identify whether the seatbelt is worn correctly based on the first webbing payout. The system may further include a second webbing payout sensor that detects a second webbing payout of the seatbelt associated with the seat. The second webbing payout is a second length of webbing of the seatbelt dispensed from a second retractor of the seatbelt. The seatbelt wear condition module identifies whether the seatbelt is worn correctly based on the first webbing payout and the second webbing payout.

A belt assembly includes a belt, a first sensor and a second sensor. The belt has a webbing and a plurality of markers distinct from the webbing and fixed thereto. The markers are equally spaced a first longitudinal distance thereon in a longitudinal direction. The first sensor and the second sensor each have an associated detection field directed toward the belt and responsive to the markers in the fields. The second sensor is a second longitudinal distance from the first sensor differing from the first distance.

In a method for operating a safety system of a motor vehicle, a corresponding safety system, and a motor vehicle equipped with such safety system, status signals from several sensor devices are captured by the safety system, wherein the status signals indicate respective status change of a functional unit of the motor vehicle. Thereafter, a chronological order of the status changes is determined and evaluated to detect a consistency or an inconsistency with the proper application of a seat belt of the motor vehicle. If an inconsistency is detected and it persists over a predetermined period of time, a control signal is transmitted by the safety system to a safety device of the motor vehicle.

A control method for an electric seatbelt retractor and an electric seatbelt retractor including a spindle (2) and a seatbelt (3) wound thereon, and an electric motor (4) driving the spindle (2) via a rotor (3) in pull-in or in pull-out direction when activated, and a sensor device (10) detecting the movement of the spindle (2), wherein a spring (11) is provided, which is arranged between the spindle (2) and the rotor (3) enabling a relative movement of the spindle (2) to the rotor (3) or to a retractor-fixed part, wherein the electric motor (4) is controlled by a signal of the sensor device (10) generated by the relative movement of the spindle (2) to the rotor (3) or a retractor-fixed part with torsional tensioning or expanding the spring (11).