Floor Guide for Sliding Doors

Abstract: This Master Thesis, executed in collaboration with Assa Abloy Entrance Systems, addresses issues and desirable features with the currently used floor guide, and several final concepts, in terms of short-term and mid-term solutions, are presented after following the product development process. The floor guide's main purpose is to keep the door leaves of an automatic sliding door running smoothly on correct track without causing any noise. The main purpose of this project was to reduce friction and noise related to the current design of the floor guide, and to generate a new final concept. Therefore, this report initially, briefly investigates the theory of friction in relation to polymers, which is the main material of the floor guide. Research and identification of customer needs were thereafter conducted to accomplish a thorough and fundamental base for further work which included a concept generation phase, a selection phase, a testing phase, and conclusion and discussion. The model used in this product development project was based on Ulrich and Eppinger's model for concept development, but slightly modified to fit this project. Results and verification of the final concepts were conducted through FEM-simulations and in close collaboration with the company. It was discovered that friction and noise related to polymers are hard to predict. Possible factors causing the noise today are; high friction between floor guide and plastic rail, misalignment of door leaf and floor guide, particles embedded in the softer material causing high friction, and undesired vibration of the floor guide. There is also a high importance in installing the floor guide correctly. Finally, the recommended solution includes a felt covered plastic block sticking up the door leaf, which is easily removed from the side when worn out. This plastic block is easily snapped onto a cylindrical metal pin.