Parallel folding armrest

A height-adjustable parallel folding armrest assembly for a seat comprising an elongated hollow support housing structure having a transverse bearing opening at its rearward end for receiving one end of a round support bar, the other end of the support bar being adapted to be non-rotatably mounted to the frame of a seat with which the assembly is to be used;

• an armrest member pivotally mounted adjacent its lower rear corner to an armrest pivot pin transversely mounted at a lower, generally forward, portion of said elongated housing structure which is longitudinally spaced from said bearing opening which receives said support bar;
• a curved rack member fixedly mounted internally of the forward portion of said elongated housing structure, tips of the internally positioned toothed surface of said rack member and the external surface of said housing structure which is behind said rack member lying in curved planes which have their centers coincident with said armrest pivot pin;
• a parallelogram linkage mounted interiorly of said hollow housing structure, said housing structure solely comprising one of the longer links of said linkage and said round support bar and said armrest pivot pin, respectively, comprising the pivot joints between said housing and the rearward and forward shorter links of said linkage, the rearward shorter link of said linkage being non-rotatably affixed to said support bar at one of its ends and to an elongated link means at its other end, the forward shorter link of said linkage comprising at least one plate-like member on which a locking pawl is mounted for selective movement into spring biased locking engagement with one of the teeth of said rack member, said locking pawl being movable by a manually actuated lever out of engagement with said rack member when it is desired to adjust the position of said housing structure and the height of said armrest.