Improvements in or relating to the treatment of metal meshes or foils so as to render them taut

摘要

689,564. Making metal meshes and foils. ELECTRIC & MUSICAL INDUSTRIES, Ltd. April 29, 1948 [June 3, 1947], No. 14609/47. Classes 83 (ii) and 83 (iv). [Also in Groups II and XL (a)] In a method of treating a thin metal mesh or foil, particularly for use in electric discharge tubes or in the manufacture of mosaic electrodes, the mesh or foil is extended on a frame and secured at its edges thereto, and is coated with a metal which will alloy with the metal of the mesh or foil to produce shrinkage thereof, and the coated and secured mesh or foil is heated to cause alloying of said two metals and taughtening of the mesh or foil in a substantially planar condition on the frame. The mesh or foil may be coated before or after it is mounted on the frame. In the example described a silver mesh 1 having 400 filaments per linear inch and a thickness of 0.0004 of an inch is cemented to a frame 2 of stainless steel, or " Invar " (Registered Trade Mark), according to the Provisional Specification, by applying a suspension of colloidal silver in oil to the edges of the mesh, applying the mesh to the frame in an extended condition, and subsequently drying out the suspension by heat so that the mesh is left adhering to the frame 2 by means of a thin layer of silver 3. The mesh may be secured to the frame by applying a nickel tape to the edges of the mesh and welding the tape to the frame through the interstices of the mesh. Before or after mounting the mesh on the frame it is coated with a thin film 4 of gold, 10-5 of an inch thick, by plating, evaporating or sputtering. The mesh is then heated in air or vacuo to a temperature of between 300‹ and 500‹ C. until alloying is observed, accompanied by a taughtening of the mesh.