The other end of {HEAD ~ the oscillating arm} 24 is formed with a plurality of {TAIL ~ internal threads} 241 adapted to engage with a gear 25 fixedly mounted on an output shaft of a motor 20 
The other end of { HEAD ~ the oscillating arm } 24 is formed with a plurality of { TAIL ~ internal threads } 241 adapted to engage with a gear 25 fixedly mounted on an output shaft of a motor 20
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH