| 摘要 |
896,729. Counter-balanced doors. GOLMET DOORS Ltd. Nov. 14, 1960 [Jan. 11, 1960], No. 926/60. Class 20(3) A counter-balance lever system in a door of the up-and-over type comprises a lever 25, Figs. 1 and 3, pivoted at an intermediate point to one limb 27 of a U-shaped bracket 23 on an upright 10 of the main frame and a tension spring 21 secured at one end to an extension rod 22 pivoted at one end 34 to one end of the lever 25, the other end of the spring being anchored to the lower end of the main frame by a bracket 20, Fig. 1, and the other end of the lever 25 being pivotally connected at 28 to the lower part of the leaf. A second lever 24 is pivotally linked between the extension rod 22 and the other limb 26 of the bracket 23. The leaf comprises a sectioned frame 14, Fig. 3, with sheets 15 reinforced by vertical ridges 16 and the whole being reinforced by horizontal channel strips 17, 18, Fig. 1. Weather strips 19, Fig. 3, are welded up to three-quarters of the height of the main frame 10 and the leaf carries the strip 19 for the other quarter. The jamb 10 of the main frame may comprise rolled steel members as shown in section in Fig. 6. |
