Considerations for improved vehicle safety and government regulations required, among other things, tests on seat belts and seat belt anchorage points. Starting with a single pulling cylinder for the introduction of the forces, a pulling machine with nine separate pulling cylinders was developed. These nine tensioning cylinders are operated hydraulically from a central unit. Each cylinder can be operated singly or in parallel with another. The operation of the cylinders is controlled by an electronic unit that compares the voltage signals representing the required and the actual values. The regulating characteristics are travel or position control, speed control, and, force control.
The principle of the test machine and objectives during different tests - for example, checking the strength of seat belts, seat belt anchorage points, door and roof rigidity, and simulation of a frontal crash with quasi-static deformation of the vehicle front-end - are described in this paper.