Abstract: A leg structure wherein a seat bottom (4) and a seat back (5) are mounted on a base frame (3) mounted bridgewise between front and rear beams (1) and (2) to constitute a seat. A diagonal member (8) is extended bridgewise from the front beam (1) supported by a front leg (6) to a lower rearward portion of the seat, a rear leg (9) for supporting the rear beam (2) is supported and fixedly mounted on a substantially intermediate part of the diagonal member (8), and lower end portions of the front leg (6) and the diagonal member (8) are fixed to a floor side rail through fixing fitting members.

Abstract: An aircraft seat convertible in situ for economy class and business class usage is described herein. In the case of a two-seater convertible seat, arm dividers are movably mounted on a seat frame for positioning thereon according to required widths of seating positions and to eliminate a middle seating position for business usage. Seat backs of two outer seating positions may be provided with mechanisms, such as slidable panels, which operate to vary the widths of the seat backs in the business class position. Alternatively, the seat backs are bodily movable on the seat frame and provided with hinge-mounted side bolsters of a compressible foam material which can be opened outwardly to increase the widths of the backs of the two outer seats with those backs moved to the two-seater business class configuration on the seat frame and the middle seating position eliminated.

Abstract: A main seat support frame includes slidable seat sections to allow the overall length of the seat and the number of sitting positions to be varied as required. The frame is provided with fixing positions for arm dividers which allow delimitation of a predetermined number of sitting positions when the seat is fully expanded corresponding to an economy class configuration and a fewer number of sitting positions of greater sitting width when the seat is contracted corresponding to a business class configuration. Since the width of the seat backs remains constant, bolsters may be attached to them when the seat is contracted for business class usage allowing for rapid conversion of the seating arrangement as between economy and business class usage.