| 摘要 |
873,946. Electric heating resistances. JOHNSON, MATTHEY & CO. Ltd. Jan. 6, 1960, No. 503/60. Addition to 849,507. Class 39(3). The electric furnace heater element of the parent Specification is a panel or sheet instead of a wire or strip. A square sheet or panel or a rectangular sheet may be used. The panel or sheet may have perforations or be made of expanded metal or alloy to increase its electrical resistance.
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