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ACE small shock absorbers secure wheelchair test bench
The demands on the quality and functional safety of wheelchairs are high. This also applies to the test series carried out by manufacturers during the development or further development of models. As part of their training, three mechanical engineers developed a drop test bench on behalf of a renowned wheelchair manufacturer and relied on ACE miniature shock absorbers to protect their design.
Arne Hankemeier, Julian Raimann and Tobias Ridder completed their training as state-certified technicians in the field of mechanical engineering as part of an in-service training course at the Felix-Fechenbach-Berufskolleg in Detmold. From the outset, the three graduates welcomed the idea of working closely with MEYRA GmbH as part of their final thesis. The company is one of the world's leading manufacturers of high-quality wheelchairs and has also made a name for itself as a supplier of rehabilitation aids.
Tobias Ridder, one of the three junior employees, also worked as a design engineer in the wheelchair manufacturer's special production department. Together with Arne Hankemeier and Julian Raimann, he developed a drop test stand for wheelchairs as his final thesis, which is intended to test the load-bearing capacity of new models in particular.
This test device is designed so that each test specimen is loaded with the maximum permissible weight and driven into the test stand. The respective wheelchair is then latched onto a gripper and lifted by means of pneumatics and dropped from a previously defined height after unlatching. In order to dampen the force of the lifting device's impact plate and protect the structure, the three technicians considered installing shock absorbers. After all, not only should the stability of the wheelchairs be proven, but the test device itself should also be stable and not have to be repaired after just a few cycles. Another argument in favor of the hydraulic damping elements was that they do not have any rebound effects thanks to their linear characteristics. This ensures that the already time-consuming drop test is not prolonged too much.
As potential cases can be laid out on the ACE homepage at any time and the corresponding products can also be ordered directly, the student team turned to ACE in Langenfeld. To their delight, the sales engineers not only confirmed the students' design data, but also provided them with free samples of four small shock absorbers.
The integration of the four ACE components was a small exercise in the end, says Arne Hankemeier and draws this positive conclusion: "We were able to make the adjustment precisely using the fine thread and reliably hold it in the preset position using the lock nut. The dampers cushion the permissible load reliably, quietly and quickly and fulfill their purpose to the full extent. We have also had the positive experience that a large load can be slowed down almost silently and without any rebound in the smallest of spaces."









