| 摘要 |
1,174,689. 689. Making ladders. R. D. WERNER CO. Inc. 6 Sept., 1968 [19 Oct., 1967], No. 42509/68. Heading B3A. [Also in Division A6] A tubular ladder rung is connected to a channel-sectioned (as shown) or tubular ladder rail by means of a malleable ferrule blank 16 (Fig. 5, not shown) of substantial thickness, which is deformed into a ferrule 15<SP>1</SP> by dies so as to grip on both sides of the rail 13, and also compress the end of the rung at 29<SP>11</SP>, and hence grip it. The rung may be of D-section, and may be fluted, and the ferrule blank may be circular with a D-shaped aperture therethrough, or may itself by D-shaped. The ferrule blank may be a loose fit on the rung initially, and be crimped into engagement therewith before being finally deformed. One end of the blank may be deformed at the same time as the blank is crimped. Alternatively, the blank may be force-fitted on the rung in an un-, or partly-deformed condition. |
