Takata Corporation

Tadahiro Nakayama

Yoshiyuki Nakano

Hiroshi Tomita

Masahiko Iwai

A pre-tensioner capable of effectively absorbing kinetic energy exerted on a coupling member connected to a piston during operation. As a gas generator is actuated to generate gas in the event of emergency, the gas is introduced into a pressure chamber. By gas pressure of the gas, a piston moves at high speed toward a taper portion of a cylinder to reach the taper portion. According to the movement of the piston, a buckle is pulled toward a bracket so that the buckle is about to reach the bottom. After that, the piston further moves to the left while deforming the taper portion. The deformation of the taper portion absorbs kinetic energy of the piston. Therefore, kinetic energy of the buckle is absorbed so as to stop the buckle softly and the impact is buffered.

Pre-tensioner

A kinetic-energy absorbing member absorbs the kinetic energy of a pull-in member such as a buckle or a lap anchor when reaching a bottom position. The kinetic-energy absorbing member, which includes a thin-walled tubular member that may be made of metal such as iron or aluminum, is arranged between a bracket and buckle. As the pretensioner is actuated, the buckle is pulled by a wire, thereby depressing the kinetic-energy absorbing member against the bracket so that the kinetic-energy absorbing member collapses and the kinetic energy of the buckle is absorbed when reaching the bottom position.

Seat belt apparatus

A pretensioner including a cylinder in which a piston slides. A side of the pipe attached to a bracket is curved at a predetermined angle. One linear portion of the pipe serves as the cylinder, and the other linear portion of the pipe serves as a gas-generator accommodating portion that accommodates a gas generator. A wire passing hole through which a wire passes is bored coaxially with the center axis of the piston sliding portion of the pipe. The piston sliding portion and the gas-generator accommodating portion can be formed of the single pipe, and the gas generator and the wire can be prevented from interfering with each other.

Pretensioner

A seat belt device including a shock absorbing mechanism to gently stop a pull-in member and to prevent a large impact force from being exerted on the pull-in member when the pull-in member is pulled in by a pre-tensioner. The device may include a wire pulled by operation of a buckle pre-tensioner at the time of an emergency, a buckle is pulled in towards a bracket while a cover contracts. Before the cover contracts to a maximum permissible contraction position, the buckle comes into contact with the free end of a shock absorbing member, and, then, is pulled in while the shock absorbing member is caused to contract. By the contraction of the shock absorbing member, the shock absorbing member absorbs impact energy of the buckle.

Growing community of inventors

Hikone, Japan

Tadahiro Nakayama