| 摘要 |
606,921. Pivoted doors. STEVENS, A. H., (Wread Overhead Door Co.). Jan. 22. 1946, No. 2078. [Class 20(iii)] In a door mounting construction in which at each side of the door 2 supporting arms 48 are clamped to a plate 16 pivoted on a horizontal hub 12 so as to be swung above the opening 3, the point of connection 56 of a supporting arm 48 with the door 2, the pivot 12, and a fixed point 35 to which a balance spring 34 is connected lie in a vertical plane when the door is open. In the 4-point installation type shown, another supporting arm 45 connected to a lower point on the door is clamped to a plate 16<1> journalled on a second pivot 11<1>. Both arms 45, 48 have extensible portions 46<1>, 46". The balance spring 34 is secured to a bar 40 mounted on plate 16 by means of a bolt and nut providing for tension adjustment; the bar itself and plate have a number of alternative orifices for connecting bolts whereby the point of connection in relation to the pivot is also adjustable. In a modification, the door is carried at each side by a V- shaped arm clamped at its apex to plate 16 and its ends secured to upper and lower points on the door. |
