a pair of springs provided on {HEAD ~ the base} means in an upright position for pushing the rotatable frame at two points in the bottom surface thereof nearly under {TAIL ~ the pair} of the bearings which support the follower roller; and 
a pair of springs provided on { HEAD ~ the base } means in an upright position for pushing the rotatable frame at two points in the bottom surface thereof nearly under { TAIL ~ the pair } of the bearings which support the follower roller ; and
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH