Cabin door- foldable step coupling
Publication Date: 2004-Nov-26
The IP.com Prior Art Database
In a foldable step of a truck, the folding movement is actuated by the movement of the cabin door of. A shaft connected to the cabin door hinge is in turn connected to a linkage that is capable of folding down the step when the door is swung open and vice versa. As the cabin is often movably suspended on the truck body, and allowed to make restricted movements in a three-dimensional floating manner relative to the truck body, a problem is to find a suitable coupling capable of absorbing these movements. According to the invention a flexible helix beam is used as a coupling between a hinge extension of the cabin door and a rotatable shaft provided for the folding and unfolding movement the foldable step. The flexible helical spring coupling is machined from one piece of material and capable of absorbing the three-dimensional movements between the cabin and body of the truck. Further, the preferred helix beam is designed with more than one helical winding to have sufficient torsional stiffness and so that adjacent turns of the windings do not contact each other during movement to avoid generation of noise.