The extension piece 22 is provided with {HEAD ~ a stop} 32 for the lever arm 27 of {TAIL ~ the drive lever} 24 
The extension piece 22 is provided with { HEAD ~ a stop } 32 for the lever arm 27 of { TAIL ~ the drive lever } 24
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH