Backpack test bench

THE SOLUTION PROVIDED BY LF TECHNOLOGIES

Main functions

Objective

To test the resistance of rucksacks to impact following a 0.25 m fall.

PROBLEMATIC ISSUES

The impact bench must be easy to use, ergonomic and aesthetically pleasing, as it is intended to be used in shops as a demonstration bench. The tests carried out and the measurements displayed must be easy to understand for an uninformed public. However, it must reproduce the same test conditions as in the laboratory.

Solution and result

The backpack demonstration bench designed by LF Technologies combines mechanical performance with attractive industrial design.

The bag tested was attached to the torso of a mannequin and weighed down to 5kg. The torso is attached to a vertical translation axis and operated by an electric actuator.

A cycle runs as follows:

• The electric actuator raises the torso to the programmed “drop” height (250 mm). This ascent is made at a slow speed so as not to cause stress on the bag due to acceleration/braking.
• The electric actuator pulls the torso down with an acceleration corresponding to gravity. This simulates a free fall of the torso, bringing it to a vertical speed of 2.1 m/s for a ‘drop’ of 250 mm.
• The electric actuator suddenly brakes the torso, simulating the impact of the torso on the ground.

The bench is equipped with a PC for programming cycles and displaying speed curves, measurements, displacement, etc. in real time. The software has been designed so that it can be used by non-experts. All the user has to do is select a pre-set record (drop height, frequency, number of cycles) and run the test.

The in-store demonstration test bench is a guarantee of the quality of the backpack. It directly demonstrates the reliability of the products marketed to end consumers.