US Patent 9243743 Support arm

A support arm includes a generally elongated support arm housing having first and second ends; an arm mounting member pivotally carried by the first end of the support arm housing, the arm mounting member pivotal throughout a first range of rotation; a device mounting member pivotally carried by the second end of the support arm housing, the device mounting member pivotal throughout a second range of rotation; a position equalizing assembly engaging the arm mounting member and the device mounting member, the position equalizing assembly pivoting the arm mounting member and the device mounting member in opposite directions throughout the first range of rotation and the second range of rotation; anda counterbalance adjusting assembly carried by the arm mounting member and engaging the device mounting member, the counterbalance adjusting assembly applying counterbalance force to the device mounting member.