Torture instrument (4)
(Other definitions for iron maiden that I've seen before include "Group" , "Box-shaped instrument of torture - no meridian (anag)" , "used to inflict pain" , "a suit, very sharp underneath the surface" , "Instrument of torture (a hinged case lined with spikes)" .)
(Other definitions for thumbscrew that I've seen before include "That could be unpleasant!" , "excruciating instrument" , "agonised by it?" , "Instrument of torture (crushing the pollex)" , "It puts the squeeze on" .)
(Other definitions for rack that I've seen before include "clouds in the > frame" , "Neck or rib of mutton" , "Wind-driven" , "Lamb cut" , "associated with ruin" .)