US Patent 7874438 Boom assembly

A boom assembly comprising: a base anchored to a structure/ground. A boom is rotatably mounted to the base at a connected end so as to be rotatable about a generally vertical axis, the boom having a device to support loads at a free end. An orientation clutch is provided between the base and the boom. The orientation clutch has a mechanism for locking a rotation of the boom with respect to the generally vertical axis so as to selectively adjust an orientation of the boom. The orientation clutch has a release configuration to allow the boom to self-adjust its orientation to align with a load pulled by the device.