With the prior art mattress 10, {HEAD ~ an operator} manually engages the edge portions of the upper and lower sheets 12 and gusset 14 by compressing a cushion 18 by the elbow and sews together {TAIL ~ the engaged edge portions} and the automatically supplied cloth tape 16 by a sewing machine 
With the prior art mattress 10 , { HEAD ~ an operator } manually engages the edge portions of the upper and lower sheets 12 and gusset 14 by compressing a cushion 18 by the elbow and sews together { TAIL ~ the engaged edge portions } and the automatically supplied cloth tape 16 by a sewing machine
OTH 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 OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH