The computer further includes a gimbal mechanism that allows {TAIL ~ the door} to move relative to {HEAD ~ the linkage mechanism} while constraining the door to the linkage mechanism 
The computer further includes a gimbal mechanism that allows { TAIL ~ the door } to move relative to { HEAD ~ the linkage mechanism } while constraining the door to the linkage mechanism
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH