| 摘要 |
899,580. Pipe supports. GRINNELL CORPORATION. Feb. 13, 1959 [Feb. 25, 1958], No. 5038/59. Class 99(2). [Also in Group XXXV] In a hanger for supporting pipes subject to vertical movements within a limited range, a lever-actuated switch controls the movement of a motor-driven jack so as to maintain the tension in the hanger constant. As shown, a motor 16 drives a worm-wheel 24, the hub of which has a female thread 38 engaging a screw 36. The screw carries a fixed arm 70 on which is mounted a switch 77. A lever 48, fulcrumed at the end of the screw, balances a load 62, connected by a support-rod 56, against the compression of a spring 66. Variation in spring compression outside of predetermined limits moves a plunger 78 to actuate the switch 77 controlling the motor 16 so as to raise or lower the screw 36 to maintain the tension in the support rod 56 constant. In a modification the spring 66 is replaced by a counterweight and the lever 48 is shaped so that the effective lever arm at which the load acts is reduced with increase in tension. |
