| 摘要 |
An upwardly and downwardly movable platform comprises a plate member (9) from one edge of which a short arm (8) extends at right- angles. Two telescoping connecting rods (4, 5), of which one (5) is a jack, are pivotally attached to said arm (8) with their opposite ends pivotally attached to a stationary member (1), the jack (5) being extensible to a greater length than the other connecting rod (4). Control means are used to operate the jack (5) and effect lowering and raising of the plate member (9) and pivoting motion thereof. <IMAGE> |
