TRW launches new generation of seat belt pretensioner SPR4

According to PR Newswire on December 10, TRW Automotive Holding Co., Ltd. (TRW) introduced the latest generation of seatbelt pretensioners, the full serpentine pretensioner retractor (SPR4). This configuration utilizes a plastic piston instead of a conventional metal component to transmit the tensioning torque, resulting in a more simplified design, lighter weight, and more compact assembly.

When the vehicle's sensor triggers the seatbelt system, the pyrotechnic gas generator is ignited and releases green gas, which expands and builds pressure in the conduit. The pressure acts on the serpentine plastic piston, which is forced into a pinion (instead of a normal steel ball). The pinion then transmits considerable torque to the seat belt retractor spool to pretension the seat belt. The entire process takes only 10 milliseconds. Compared with the traditional system, this new design uses a more lightweight plastic material, so that the tension can be formed faster; Second, unlike the case of two rigid steel parts in the traditional system collided with each other, the snake-shaped plastic damping The habits greatly reduce the initial peak when colliding gears, and help to reduce the wear of SPR4 components. Since the SPR4 consists of only four main components (pistons, gas generators, ducts and pinions), its design facilitates the automotive manufacturer to further optimize the installation space.

Since 2001, TRW's seat belt retractor ESA 4.0 has been used on many vehicle platforms. The new SPR4 will be commissioned in 2013.