Anti Collision Height Limit Switch Potentiometer Tower Crane Lifting Hook Safety

Anti Collision Height Limiter Potentiometer Tower Crane Lifting Hook Safety 

Function

When DXZ is used for hoisting limit it is used to avoid issues because of wrong operating of hoisting. It will stop the hoisting movement before hoisting pulley block touch jib trolley, or hook reach ground level or wire rope remains in drum less than 3 turns)

Working principle

Input shaft of DXZ limit switch is driven by shaft of hoisting drum directly or by the small pinion on input shaft of limit switch which is engaged with toothed ring on drum. D)XZ limit switch records the rotated turns of drum (rolled o unrolled length of hoisting wire). Hoisting movement will be stopped when pulley block approach jib trolley with 1m distance or before hook touch ground

Adjusting

Do adjusting with no load on hook. Press down the contacts 4 WK, 1WK to confirm if the contacts (WK)are correct for hoisting up and down.

a. Hoisting upper limit

Operate hoisting up with 2 falls(SM/DM trolley )until pulley block is around 1m far away from jib trolley, adjust worm gear shaft (4Z ) until cam (4T) press down the contact (4WK ) and contact (4 WK) changes over, Tighten the nut M5.

b. Hoisting lower limit

Lowering down the hook with 4 falls (SM/DM trolley )until hook almost reaches ground (make sure there is at least 3 turns of wire rope remaining on hoisting drum). Adjust worm gear shaft (1Z) until contact (I WK) is pressed by cam (IT) and contact (I WK) changes over, Tighten the nut M5

c. Verify the setting of upper and lower limit, readjust if needed

Parameter