Stopp För Mekansiskt vevbord

Sammanfattning: ROL Ergo is a company that manufactures and develops height-adjustable tables. Their product line-up consists mainly of electrically operated tables, but also a small-scale of tables where the height is determined by a hand-driven crank. One problem with ROL Ergos hand-operated crank table, PR25 2-column 2-stage crank, is the function of stopping the table after 470 mm which is the tables desired stroke. The solution the existing table have, to prevent this from happening, is a plastic stop mounted on top of the table’s outer legs. This plastic stop is intended to stop the table when the leg reaches its highest position. The hand crank used to change the height of the table have an integrated torque clutch which is used to prevent that the torque applied to the crank exceeds 4.3 Nm. However, the force applied to the plastic part that is generated by the hand crank is greater than what the plastic part is constructed for. This results in the stop being pushed out of its position and must be mounted back by hand, or in worst case, breaks. This report covers the steps taken to find a solution to this problem. Initially, the forces generated by the hand crank in the tables height adjustable system is needed. When these forces were calculated the process of finding concepts and solutions could begin. When a final concept was defined, the solution was verified with simulations and physical tests to ensure the concept’s stop function. Through this process the work resulted in a concept where a C formed ring is mounted onto the table’s thread bars. This ensures that the thread bars are prevented to thread further than the desired height. By using results from calculations, simulations and physical tests, the developed concept could be verified to withstand the forces generated by the hand crank in order to stop the table at the desired stroke.