| 摘要 |
713,509. Linkwork. MERCIER, J. July 14, 1952 [July 17, 1951], No. 17755/52. Class 80 (3) [Also in Group XXV] . A sliding door 20 is operated by force applied at 24, Fig. 3, to a lever 22 pivoted at 23 to the door and adapted to fulcrum about either one of a pair of fixed stops 25, 26 provided on one side of the pivot 23, or about a fixed stop 27 on the other side of pivot 23. The arrangement is such that, in the opening direction F, the lever fulcrums on stop 25 and functions as a lever of the third order, while in the initial part of movement in the closing direction the lever fulcrums on stop 27 and moves between the stops 25, 26 to function as a lever of the second order to apply additional force for unseating the door, the lever thereafter fulcruming on the stop 26 to function as a lever of the third order. In a modification, Fig. 6, the pair of stops is provided by the ends of a slot 42 in a fixed bracket 43. A link 45 has a pin 46 at one end engaged in the slot, and is pivoted at the other end to the upper end of a lever 38 pivoted at 39 to a door 30. The lower end of the lever fulcrums on a stop 47 in the initial part of the opening movement. The piston rod 36 of a hydraulic jack is pivoted at 37 to the lever. In a further modification one end of the lever is slotted to receive a fixed pin, and the lever is pivoted to a link pivoted to the door. In yet further modifications the lever is slotted to receive a pin fixed to the door, or is provided with a roller engaged between parallel guide surfaces provided on the door. |
