a pair of secondary springs for adjusting the spring rate of {HEAD ~ said at least one pair} of {TAIL ~ primary springs}, said secondary springs each fastened at one end thereof directly to said arm and at the other end thereof to said head 
of
a pair of secondary springs for adjusting the spring rate of { HEAD ~ said at least one pair } of { TAIL ~ primary springs } , said secondary springs each fastened at one end thereof directly to said arm and at the other end thereof to said head
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH