Patent ID: 6918160

Claim:
A four-bar hinge linkage and fold-down armrest assembly for marine use in watercraft seating applications, comprising a frame made up of a platform board and two laterally spaced sideboards dependent therefrom with their longitudinal dimension running parallel to that of said platform, said frame being adapted to be pivotally supported for four-bar hinge articulation from a stationary upright back panel board of a boat bench seat, sofa or the like, said articulation being provided by first and second four-bar hinge linkages, each of said hinge linkages comprising a four-bar linkage made up of a right angle board-mounting bracket, a main hinge link, a shorter control and locking link and an armrest mounting bracket, said right angle board-mounting bracket having one of its flanges adapted to be secured by screws to the seatback panel, the other flange of said right angle board-mounting bracket being adapted to provide a stationary pivot mount for one end of said hinge link and for one end of said control/locking link, said armrest mounting bracket of each said hinge linkage being secured to the outboard side of an associated sidewall of said frame by mounting screws that pass through holes in said armrest mounting bracket and thence through a spacer washer, thence through pre-formed holes in said sidewall and into a pre-mounted standard T-nut, said armrest mounting bracket providing a pivot connection of said links to said armrest frame by pivot pin rivets mounted in said armrest mounting bracket and passing individually through associated holes one in the swinging end of each of said links, whereby said four-bar hinge linkages, in articulating said armrest between an upright stored position and a fully folded-down in-use position, are operable such that in the fully folded down in-use position of said armrest the swinging end of said control/locking link swings up and beneath said hinge link so that in the armrest fully folded-down in-use position an inclined end edge of said control link abuts in line-to-line linkage-locking contact the underside edge of said hinge link, such that in this condition, each said linkage is locked together to each form a triangular support truss, and wherein the placement of the abutment locking point in each linkage is such that each said linkage is locked together with said abutment at a point along said hinge link where it provides a strong support structure, does not create a user pinch point and such locking point is oriented well forward of the linkage pivot point so said links will not push by one another.