Historical
SAE J 999-2011 (SAE J999-2011)
Crane Boom Hoist Disengaging Device ( Reaffirmed: Aug 2011 )
This standard applies to cranes which are equipped to adjust the boom angle by hoisting and lowering means through rope reeving. The purpose of this standard is to define the function and to stipulate the requirements of an automatic device to prevent raising a variable angle boom above its highest specified angle.
Society of Automotive Engineers [sae]