Flying Coffin Hardware

Hi everyone, I'm doing my homework as I am restoring my home back to its original state... While I haven't had the chance to see a flying coffin (the floating /suspended kitchen cabinet) in person I was wondering if anyone out there had insight on the matter & how the cabinet was secured to the ceiling. 
In my house model the black metal rod went into one of the beams that ran parallel to the kitchen. 
Were the rods threaded like a wood screw? or were they threaded like bolt with a nut and washer & held in place below the roofing material? 
Also did the rod connect to some kind of angle iron to support the cabinet and its contents?
Thanks in advance