An Improved Apparatus for Detecting the Overloading of Chains or Ropes of Cranes, Lifting and Hauling Appliances, and the like.

摘要

19,073. Denison, S. Sept. 21. Rope or chain stress indicators. - A device for indicating the overloading of a lifting or hauling cable is enclosed within a drum-shaped casing F, Figs. 1 and 2, and is constituted by an upper cross-head A, fixed to the casing by bolts B and a relatively movable cross-head G of spider-like form, suspended by bolts J from plates H encircling the bolts B and resting upon helical springs D supported upon the floor of the casing. The upper cross-head is connected to a shackle A' and the lower one by a rod E to the shackle El. Overloading is indicated by the closing of a circuit containing batteries K1, K' and an electric bell K3. This is effected by an adjustable contact N upon an arm M, carried by the movable cross-head G coming into contact against the action of the springs D with a fixed contact L. A trial switch 0 operated from an opening in the casing is employed for the purpose of bridging the contacts L, N at any time. The movable cross-head may be also arranged to throw out signals through slots in the casing in addition to sounding the alarm. In the arrangement shown in Fig. 4, one or more indicators P are thrown out when the spring- controlled arm P7 is released by the withdrawal of the lever P1 by the cross-head G. The arm P7 also closes the circuit of the bell by engaging the contact L. This form of indicator is re-set by the attendant. In other arrangements, more than two spiral springs and other means of indicating and releasing the signals and of nesting the details are employed.