GB800454A - - Google Patents

Abstract

800,454. Ohmic resistors. IGRANIC ELECTRIC CO., Ltd. April 18, 1955 [April 26, 1954], No. 11084/55. Class 37. In a resistor of the type having a frame supporting insulated rails on which grids of resistance material are stacked, the grids have lugs and a body portion which lies wholly to one. side of the centre line of the grid, thus enabling the grids to be readily mounted and interchanged and their heating to be minimized. Figs. 1 and 4 show a resistor in which insulated supporting rods 12, 14 and 16, 18 are attached to brackets 20, 22, 28, 30, the former pair of which are fixed to channel members 24, 26 and the latter pair are slidably carried by these members. Grids 10, Fig. 5, punched from resistance material such as nickel-chromium, coppernickel or any suitable chrome-iron alloy have lugs 10b, 10c and a body portion 10a which are disposed on opposite sides of the centre line of the grid, and are stacked in zigzag fashion on the supporting rods, alternate grids being preferably welded together at one end and spaced apart by insulated spacers 32, Fig. 6, at the other. Electrical connections to the resistor are made by terminal plates 34, Fig. 3, inserted in the stack as required or connecting tabs may be formed on the grids. The brackets 20, 22 and 28, 30, as shown in Fig. 1, are free to slide over pins 46 as the grids 10 expand and contract longitudinally with heating and cooling. By removing fasteners 42, Fig. 1, the grid stack may be withdrawn without altering the spacing of end channels 24, 26. In a modification, shown in Figs. 7 and 8, mounting rods 104 and 106 are held by channel members 100, a groove 126 in nut 112 allowing the rods to slide between tabs 120, 122 on longitudinal change in dimension of the rod. Change in length of the grids is taken up by the sliding of rod 104 in cut-out 124. The grids 142 may be shaped as shown in Fig. 9.