Abstract

A wiper assembly for surface maintenance vehicles has a non-destructive failure mode when impacting stationary objects, or otherwise becoming subject to instantaneous or rapidly increasing resistance to forward movement, due to an improved mechanical coupling. The improved mechanical coupling for a wiper assembly absorbs some of the impact stresses imparted to the wiper assembly. Portions of each improved mechanical coupling designed to absorb the stress forces deforms most nearest the location of increasing resistance to forward movement, and may either become fully disconnected if the stress force reaches a threshold force value or recoils to the original mounting location after absorbing forces that are less that said threshold force value. The threshold value force at which a wiper assembly dislodges from its mounting location is designed to avoid damage to the wiper assembly, the articulated mounting member (if any), and the maintenance vehicle itself. The mechanical coupling provides independent range and precision of motion and mechanical tolerance with respect to discrete instantaneous forces affecting the wiper assembly so that the wiper blades exhibit an increased effectiveness in response to contact with diverse size obstacles present on, and obstacles adjacent to, a surface to be cleaned. The improved mechanical coupling utilizes a resilient, deformable member that adds a modicum of additional travel in response to stress forces imparted to a wiper assembly. Accordingly, the teaching of the present invention may be applied to previously manufactured surface maintenance equipment and vehicles in the form of retrofitted mechanical couplings, requiring modest engineering and re-installation efforts.