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