Utveckling av golvlucka för hoppgropssystem i kommunal idrottshall
In this thesis a concept for floor hatches for foam pits has been developed. Since there is an existing solution that is powered by hydraulics and is expensive, the goal was to develop a cheaper solution, as simple as possible.A number of different concepts were developed and evaluated. A concept with five sections that are pulled to the side and stacked on each other was chosen as it was thought to have the lowest risk of crush injuries and to be easiest to manage and control. In the opening behind the foam mattress a lifting table is placed to regulate the height of the stacked sections.To be allowed to be installed in the floor of sports halls the sections must be dimensioned according to the construction standards for these types of buildings. Different dimensions of beams in steel and wood materials were evaluated and of those, who lived up to the requirements of the standard, a concept was chosen. In this concept each section consists of six beams of glued laminated timber with cross section area of 225x90 mm covered by two plywood boards with 12 mm nominal thickness. Each section weighs 282 kg and the long-term deflection due to the self-weight is 0.68 mm. The deflection because of the imposed load is 6.25 mm with a nominal point load of 450 kg, 7.2 mm with a nominal distributed load of 700 kg/m2and 1.03 mm with a load of 100 kg/m2.Since the weight could be kept relatively low, the sections can be moved by hand and thus no external driving is needed. Instead of using wheels, a solution with slide bearings/slide plates has been developed but it needs to be examined if the friction is low enough for it to work. In other cases, a solution for how to move the wheels so that the sections don?t need to rest on them in the closed position should be developed.