Patent ID: 8905204

Claim:
A mechanical arm assembly comprising: a first arm having a first end and a second end; a first roller thrust bearing mounted to said first end and to a ceiling; a second roller thrust bearing mounted to said second end each roller thrust bearing comprising a first bearing body and a second bearing body able to rotate relative to each other, wherein the center of said roller thrust bearing is open to allow gas hoses, electrical conduit, or other hoses or cabling to be passed through, each roller thrust bearing having a solenoid powered brake comprising: two brake shoes each with a break pad mounted to a hinge body affixed to said first bearing body; a brake drum mounted to said second bearing body; a tension spring pushing said brake shoes against said brake drum; and a mechanism for disengaging said brake shoes from said brake drum comprising: a slider body with space for two pins, two ball bearings, and a plunger with sloped surfaces on one end and a mounting provision on the other end; a solenoid attached to said mounting provision; and said sloped surface shaped such that when said solenoid is activated and said solenoid moves said plunger, said sloped surface pushes said ball bearings apart which pushes against said pins apart which in turn pushes against said brake shoes thereby disengaging said brake shoes from said brake drum and permitting said first bearing body to rotate relative to said second bearing body.