A switching device is operatively connected to the shackle device and is actuated when {HEAD ~ the predetermined magnitude} of relative displacement between {TAIL ~ the pistons} is reached 
A switching device is operatively connected to the shackle device and is actuated when { HEAD ~ the predetermined magnitude } of relative displacement between { TAIL ~ the pistons } is reached
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH