Abstract: An electrical heating mat comprises an electrical resistance heating wire arranged in a loop formation with substantially straight leg portions between curved portions. A plurality of spaced apart spacer strips made of thermoplastic material are provided to hold the heating wire its looped formation. Each spacer strip comprises an elongated narrow strip body having a plurality of spaced open-sided were receiving loops having an inner dimension assuring snap-fit reception of the wire therein. One end of each strip body is provided with a snap-in coupling member dimensioned to snap-fit into a wire receiving loop at the end of an adjacent spacer strip to enable a plurality of mats to be interconnected together to form a larger unit. Spacer lands extending generally parallel to the leg portions of the heating wire may connect the spacer strips together.
Abstract: The present spacer strips are used to form, for example, electrically heated mats, whereby the strips hold the elongated heating elements in a fixed position relative to each other. For this purpose the strips are provided with grooves into which the elements are inserted with a press-fit and preferably with an elastically yielding press-fit. The strips are further provided along the ends with coupling means for connecting several strips in series with each other. The present strips are formed by heating thermoplastic sheet material and stretching the sheet material over a grooving tool plate then the sheet is pressed or sucked into the grooves of the tool plate. After cooling and removal of the grooved sheet, the sheet is cut into strips whereby the cut extends substantially across the grooves.