Patent ID: 11970132
Assignee: AUTOLIV DEVELOPMENT AB
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A pyrotechnic tightening device for a safety belt of a safety belt unit having a force-limiting unit, comprising
a gas generator, and
a piston, which is guided in a pipe and which closes a pressure chamber inside the pipe, wherein
a pressure can be applied to the pressure chamber by the gas generator, and
the piston can be driven by the pressure present in the pressure chamber to perform a tightening movement which can be transmitted by means of a force-transmitting device to the safety belt, wherein
the piston is formed in two parts consisting of a main body and a contact part arranged on the side of the main body facing the force-transmitting device, wherein
the contact part has a greater strength than the main body, wherein
the main body encompasses the contact part in a form-fit at an end face facing the force-transmitting device, and wherein
the main body has an annular protruding collar having at least one projection that is directed radially inward and partially covers the end face of the contact part in an axial direction such that the annular protruding collar of the main body encompasses the contact part in the form-fit and the contact part is securely held on the main body.