ELECTRIC HEATING APPLIANCE AND METHOD OF MAKING SAME

摘要

ELECTRIC HEATING APPLIANCE AND METHOD OF MAKING SAME An electric heating appliance such as an electric comforter and a method of manufacturing the same in which two inner thermal insulation layers of resilient fiber fill material, one of which has substantially greater thermal conductivity than the other, and two outer textile fabric layers are stitched together along parallel spaced lines arranged in pairs of rows to form a shell with a series of laterally spaced channels in which are disposed an electric heating wire. Each inner thermal insulation layer has facing means on its inner surface to facilitate insertion of the heating wire into the channels and to resist penetration of the heating wire into the layer. Successive shells may be formed in a continuous manner by passing webs of the outer and inner layers in juxtaposed relationship through a multi-needle stitching machine which stitches the webs together with groups of spaced parallel rows of stitching. The stitching of a central main area of the webs is intermittently interrupted to provide seriatim sets of rows of stitching separated at their respective ends by unstitched areas. The stitched together webs are transversely cut along lines passing through the respective unstitched areas to provide successive shells each with the channels thereof open at their respective ends for subsequent insertion of the heating wire into the channels.