Seen from afar, the construction looks more like a sculpture than a toy. In the middle of the former State Garden Show grounds, the impressive construction illustrates woodworking then and now through the ages. This makes technology tangible and understandable in the truest sense of the word and therefore also exciting for children and young people. It is no coincidence that Maier Metall-Technik from Abtsgemünd was responsible for the concept. The provider of customized solutions in metal and sheet metal processing can look back on a tradition of over fifty years. The production portfolio of the company from the Ostalbkreis region ranges from sophisticated prototypes and individual parts to complete assemblies and small series. Always linked to the claim of offering top performance in metal technology.

Whether welding, plasma cutting or the assembly of components, customers generally receive everything from a single source in high quality. ACE Stoßdämpfer was chosen as an equally powerful partner for the combi saw. "As we wanted to build a sawing toy, it was clear to us that we had to pay particular attention to safety," says design engineer Walter Reeb.

Right from the start, he and his team envisioned a typical tree saw in the lower part, which could be operated by one or two people. The special feature: This handsaw was to be able to operate a circular saw in the upper section at the same time. To achieve this, the force used is transmitted purely mechanically from the bottom to the top via a ship-like arrangement. However, it was important to ensure that the movements were not carried out too quickly. This could have resulted in the operator slipping dangerously.

Brake cylinder for resistance, tubular structural damper as travel limiter

To prevent this from happening, a hydraulic brake cylinder is fitted at the top via a lever, which provides a certain amount of resistance. At the bottom, two tubular structural dampers are also installed in the end positions as travel limiters and end stops. This also serves the purpose of safety, as the circular saw must also be prevented from hitting the ground.

Like Maier Metall-Technik, ACE also focuses on high-quality and customized solutions. The use of two different dampers for different purposes illustrates this, and ACE has a wealth of other solutions for eliminating shocks and vibrations. The hydraulic brake cylinders used in Schwäbisch Gmünd are particularly suitable for damping swinging masses. They can be used as single-sided brakes or, as in this case, as double-sided brakes. If the speed is throttled on one side, a free return stroke in the opposite direction would occur in the pull or push direction.

ACE offers hydraulic brake cylinders in gas spring design with diameters from twelve to 70 millimetres and with strokes from ten to 800 millimetres. (Image: ACE)

The brake cylinder can generally be adjusted sensitively and provides a constant feed speed, primarily to slow down the stick-slip effect that often occurs when sawing. The maintenance-free, ready-to-install and closed systems are available in body diameters from twelve to 70 millimetres and in stroke lengths of up to 800 millimetres. In this case, an element with a diameter of 40 millimetres, a stroke of 150 millimetres and a maximum compressive force of 10,000 newtons was used.

The Tubus TA family: structural dampers of this type are reversible and absorb the energy that occurs with a degressive damping characteristic. (Image: ACE)

The two TA72-29 structural dampers used belong to ACE's Tubus line, which consists of solid-state elements made of a material known as co-polyester elastomer. Tubus are always used when precise stopping is not required. The machine elements are cost-effective alternatives to hydraulic end position damping.

The type used here is characterized by a degressive characteristic curve, i.e. there is a high energy absorption at the start of the stroke. In this form, the two structural dampers are able to absorb so much mass force per stroke with a low dead weight that operators and end positions are protected. With a service life of up to one million load cycles, they exceed the service life of urethane dampers by a factor of twenty, last ten times longer than rubber dampers and five times longer than steel springs. Designed for use in temperatures ranging from minus 40 to 90 degrees Celsius, the two dampers have been in use in the Schwäbisch Gmünd forest for years now. as