An inertia disc mounts within {HEAD ~ the housing}, mounting to the housing through a spherical bearing which permits rotational and radial displacement of the inertia disc relative to {TAIL ~ the housing} 
An inertia disc mounts within { HEAD ~ the housing } , mounting to the housing through a spherical bearing which permits rotational and radial displacement of the inertia disc relative to { TAIL ~ the housing }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL