However, the customary cushion cover sewing method has the drawback that since the edge portions of the upper and lower sheets 12 and gusset 14 are sewn together with {HEAD ~ the cushion} 18 forcefully compressed by {TAIL ~ the physical force} of an operator, the operator is ready to be fatigued 
forcefully compressed by
However , the customary cushion cover sewing method has the drawback that since the edge portions of the upper and lower sheets 12 and gusset 14 are sewn together with { HEAD ~ the cushion } 18 forcefully compressed by { TAIL ~ the physical force } of an operator , the operator is ready to be fatigued
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH