FIG 5 illustrates a modified form of the invention wherein the jack drive unit 27 is connected to a planetary gear drive 81 which connects to {HEAD ~ the shaft} 24 of {TAIL ~ the jack} 
of
FIG 5 illustrates a modified form of the invention wherein the jack drive unit 27 is connected to a planetary gear drive 81 which connects to { HEAD ~ the shaft } 24 of { TAIL ~ the jack }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL