Abstract: A seat has an armrest pivotable between an operating position approximately parallel to the seat cushion and a position parallel to the seat back, and translatable in the operating position between two heights with respect to the seat cushion. A first bracket fixed to the seat back includes an arcuate cut-out and a pin-receiving portion. A second bracket is pivotably connected to the first bracket opposite a first end of the cut-out, and is pivotably connected to the armrest, the distance between the pivotal points approximating the radius of curvature of the cut-out. The armrest has a projecting pin engageable in the cut-out, which serves to guide the pin, and thus the armrest, during rotation of the armrest. A recess at the first end of the cut-out allows the pin to disengage therefrom and the pin can then be raised to the level of the pin-receiving member and supported thereby.