| 摘要 |
375,518. Loft ladders. BARRACLOUGH, G. H., 11, Redburn Drive, Shipley, near Bradford. June 4, 1931, Nos. 16219 and 19960. [Class 20 (ii).] Relates to collapsable stairways of the lazytongs type, of the kind which can be accommodated within a hatch opening when in the collapsed or inoperative position. According to the invention, the sides and back of the stairway are formed with lazytongs or lattice bars F, N, respectively, Figs. 1 and 2, the side lattice bars being connected to brackets D attached to the hinged or pivoted hatch cover E. In the form shown, the brackets D pivot about a transverse rod C, the extremities of which are journalled in brackets B secured within the hatch opening A. One of the uppermost pair of side bars F on each side carries an antifriction roller K which engages in a slot J in the bracket D. The other uppermost bars are pivoted to the rod C. The lowermost bars are interconnected by transverse angle-irons, rods, or bars M. The lattice bars N are pivoted centrally together about pins H<1> each of which carries a bracket P housing a pin G<1> on which pivots a second bracket R. Each bracket R is secured to a step or tread L the ends of which are connected in known manner to the advance portions of the bars F. To facilitate the opening and closing movements, overhead balance weights are connected to the stairway and cover by wire cables U, W, respectively. The cable U passes over overhead pulleys and around a pulley V, and is secured at the lower end to a bracket S carrying a bifurcated hook T. This hook is provided to receive the doll-head of a rod which is used for pulling down the stairway. In a modification, the cover E is hinged directly to the side of the hatch opening, the brackets B are dispensed with, and the rod C is carried by the brackets D. |
