Bridge, gantry crane hoisting limiter used

First, the topics in accordance with
  To improve production efficiency, reduce labor intensity of workers, widespread use of lifting machinery for industrial and mining operations. DHI · DCW Group Co., Ltd. is the design and manufacture of large mining smelting equipment, port handling machinery, heavy bit, bridge,  gantry crane  hundred sets, lifting operations everywhere. In recent years, Dalian Heavy Crane Group Limited and a number of enterprises in Dalian, in with the main (sub) hook flip the workpiece, lifting operations, due to operational reasons ( overhead bridge crane  driver to concentrate on the work piece, ignoring the lifting hook position), occurred over winch hook, Jiaoduan wire rope, hook off the accident, the personal safety of ground operations, resulting in a great threat.

Second, the technical analysis
 According to GB6067 - 85 "crane safety regulations" the relevant requirements, from the ceiling bit of the action stroke is 300-500mm.  bridge crane  drivers in the main (sub) hook action, flip the workpiece, focused mainly on the workpiece, while ignoring the main (sub) lifting hook position, until the hammer up to a certain height (currently Dalian Heavy Crane Group Limited bridge, gantry cranes from the ceiling using heavy hammer positioner), limiter action, due to inertia (due to the hoisting mechanism operating lever did not return to zero), hook continue to rise over the stopper, produced a winch phenomenon. But if the hook is about to hit the hammer stopper, can give the driver a timely warning to take immediate measures to lifting mechanism operating levers back to zero, stop lifting hook, it will not produce an increase inertia, but does not produce the phenomenon of over-winch

Three, corresponding to the measure and effect
  Based on the above analysis, corporate organizational units concerned crane engineering, electrical technicians, security staff to discuss, brainstorm and decided to bridge, gantry crane hoisting limiter installed alarm devices. Ie Crane (deputy) hook hammer at the limit, as police probe sensor installed in the crane cab mounted alarms. When the hook since risen hammer at the time, motion sensors, alarms, alarm (working diagram attached), prompt drivers to pay attention crane hook lifting position, and immediately take appropriate measures.
The device is installed on the crane, after numerous tests the effect is very obvious, reaching security purposes, for the lifting operation adds a security measure.

Four, over hoisting limiter alarm device works
  When the hook near the hammer when the received signal sensors, proximity switches SQ closed contacts KM pull, turn the alarm crane cab allows the alarm to warn the operator hook close to the limit, corrective action should be taken immediately , to avoid the phenomenon is now over winch.