GB540316A - - Google Patents

Abstract

540,316. Calculating-apparatus. BALL, W., KEEN, G. P., and BRITISH ADDING & CAL. CULATING MACHINES, Ltd. April 29, 1939, No. 7761/40. Divided out of 540,283. [Class 106 (i) ] In a machine in which each key in a column or group of keys is depressed against the action of spring means, means are provided for simultaneously adjusting the spring means acting on all the keys in a 'column or group. In the form shown in Fig. 2 applied to a multiple bank machine of the type described in Specification 540,283 each key 25 is provided with a spring 137 and co-operates with a notched detent bar 128. When a key is depressed the corresponding detent bar is reciprocated against the action of its spring 131 and holds the key in depressed position. The springs 131 in all the columns of the keys are attached by arms 132 pivotally mounted on a rod 133 secured to an adjusting lever 255 that co-operates with a notched plate 258 and is settable to one of a number of positions to regulate the spring action. As shown in Fig. 3, applied to a ten key machine the individual key springs 167 are supported on forked plates 168 which straddle cam bars 170 operatively connected to an adjusting lever 178. Specifications 263,505, 288,672, [both in Class 106 (i)], 343,448, 343,473, 343,474, 343,475, 343,476, 352,958, 540,315 and 540,320 also are referred to.