| 摘要 |
<p>PURPOSE:To provide a light operation by so selecting diameters, etc., of large- diameter and small-diameter sprockets that a moment of a divisional force of a gravity to be applied to a unit in a moving direction, around the large- diameter sprocket and a moment of a pressing force of a gas spring around the small-diameter sprocket are reverse to each other. CONSTITUTION:A pair of shafts 6 to which a large-sized sprocket 4 and a small-diameter sprocket 5 are coaxially secured, are disposed under a unit 2 in a console 1. A divisional force f of a moving direction of a gravity to be applied to the unit 2 is applied to a chain 7 through a bracket 9, and a moment around the sprocket 4 is operated at the shaft 6. A pressing force P of a pressing rod 10a due to gas pressure in a gas spring 10 is applied to a chain 8, and a moment around the sprocket 5 is operated at the shaft 6. The diameters of the sprockets 4, 6 and the pressing force of the spring 10 are so selected that both the reverse moments become equal.</p> |
