Gravity flexes the opposite end of {HEAD ~ the beam} or wire into {TAIL ~ contact} with the tubular case, creating a closed electrical circuit 
Gravity flexes the opposite end of { HEAD ~ the beam } or wire into { TAIL ~ contact } with the tubular case , creating a closed electrical circuit
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH