| 摘要 |
384,534. Sliding windows. LARSON, A., 455, South York Street, Elmhurst, Illinois, U.S.A. April 19, 1932, No. 11235. [Class 20 (iii).] Sashes balanced by springs.-A device for balancing the sliding sashes 23, 25 of a window comprises a spiral member 17, Fig. 3, which is attached to a sash and which engages in a cap 13 of a spiral spring 10 which is secured at its other end to the window frame 22. The arrangement is such that the springs are subjected to increased or decreased torsional stresses as the sashes are raised or lowered. The cap 13 has an externally threaded stem which engages with the coils of the spring and thereby prevents the disengagement of these two parts. As applied to the lower sash 25, the member 17 is secured by a screw 26a to the lower edge of the sash, while the spring 10 is connected to the upper edge of the window frame. The member 17 is so formed as to provide a convolute groove 26 and ridges 27, 28, the latter fitting neatly into a substantially rectangular opening 16 in the cap 13. The pitch of the groove increases gradually from one end of the member 17 to the other, and is such that the sashes will not move from the closed position under the action of the springs alone. |
