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