Vehicle impact absorbing bumper device with collision detector

Claim 2

A vehicle impact absorbing bumper device having a collision detector comprising: an impact absorbing bumper device having a cylinder attached to either a mounting stay on the body of a vehicle or a bumper located opposite to said mounting stay; a first piston attached to the other of said mounting stay and said bumper to be movable in said cylinder relative thereto; an impact absorbing medium in said first piston; a second piston one end of which is inserted in said first piston, the other end of which is fixed to either one of said mounting stay and said bumper which is secured to said cylinder, said impact absorbing medium being compressed by said second piston at the time of a collision for absorbing the impact of the collision; and a collision detector having voltage generating means provided in said cylinder and including a stator for providing a magnetic path and a generating winding for generating the voltage in accordance with the variation of the magnetic reluctance of said magnetic path, and a plurality of alternately arranged projections and notches madE of a magnetic material and formed on said first piston to be movable in said generating means to change said magnetic reluctance.

Claim 3

The vehicle impact absorbing bumper device of claim 1 further comprising means for determining when the period of the voltage generated by said generating means is less than a predetermined time interval.

Claim 4

The vehicle impact absorbing bumper device of claim 2 wherein said time period detecting means comprises a clock pulse generator, means for gating said clock pulse generator in response to the occurrence of a voltage generated by said voltage generating means, and means for generating an actuating signal when a second voltage is generated by said voltage generating means before a preset number of pulses have been generated by said clock pulse generator.

Claim 5

A vehicle impact absorbing bumper device having an integrally formed collision detector comprising in combination: an impact absorbing bumper device having a cylinder attached to either a mounting stay on the body of the vehicle or a bumper located opposite to said mounting stay; a first piston attached to the other of said mounting stay and said bumper to be movable in said cylinder relative thereto; an impact absorbing medium positioned in said first piston to substantially fill the space therein; a second piston one end of which is inserted in said first piston, the other end of which is fixed to the mounting stay or bumper which is secured to said cylinder, said impact absorbing medium being compressed by said second piston at the time of a collision for absorbing the impact of the collision; and a collision detector including voltage generating means provided on said cylinder for generating a plurality of voltage pulses in response to relative movement of said first piston and said cylinder, said generating means including a stator for providing a magnetic path and a generating winding for generating the voltage in accordance with the variation of the magnetic reluctance of said magnetic path, and a plurality of alternately arranged projections and notches formed of a magnetic material and positioned on said first piston integral therewith to be movable with said piston to change the magnetic reluctance.

Claim 6

A vehicle impact absorbing bumper device having an integrally formed collision detector comprising in combination: an impact absorbing bumper device having a cylinder attached to either a mounting stay on the body of the vehicle or a bumper located opposite to said mounting stay; a first piston attached to the other of said mounting stay and said bumper to be movable in said cylinder relative thereto; an impact absorbing medium positioned in said first piston to substantially fill the space therein; a second piston one end of which is inserted in said first piston, the other end of which is fixed to the mounting stay or bumper which is secured to said cylinder, said impact absorbing medium being compressed by said second piston at the time of a collision for absorbing the impact of the collision; and a collision detector including voltage generating means provided on said cylinder for generating a plurality of voltage pulses in response to relative movement of said first piston and said cylinder, said generating means including a stator for providing a magnetic path and a generating winding for generating the voltage in accordance with the variation of the magnetic reluctance of said magnetic path, and a plurality of alternately arranged projections and notches formed of a magnetic material and positioned on said first piston integral therewith to be movable with said piston to change the magnetic reluctance.