Patent GB-450442-A (GB)
Title: Improvements in weighing machines
IPC: G01G19/00
Filed: 1934-10-15
Abstract: 450,442. Weighing-apparatus. BUNDE, A., Gross-Drensen, Filehne, Netzekreis, Germany. Oct. 15, 1934, Nos. 29484 and 29485. Convention dates, Oct. 13, 1933 and Oct. 10, 1934. [Class 143] In a method of weighing out ingredients for mixtures having a predetermined weight for the total weight or for one of the ingredients, weighing is effected against a scale graduated in ratios or percentages and corelated by variable moans with the weighing machine so that a predetermined weight on the machine may be caused by appropriate change in the variable means, to give a selected reading on the ratio or percentage scale, whereby a ratio is established which applies to other weighing operations carried out by the machine reading on the percentage scale. As shown in Fig. 1, the platforms 1, 1<1> are connected by lever systems to a tension band 3 passing round a cam on a fulcrum shaft 5. A pendulum weight 7 is adjustable radially of the shaft by means of a hand wheel 14 and bevel wheels 16, 17, a pointer 20 being adjusted simultaneously along a scale of weights 21. When the pendulum moves under the load on the platform 1 a rack-operated pointer 13 is moved over a dial 12 graduated in percentages. A circular formula card R<1> is arranged within the dial 12 and is divided into successive arc lengths indicative of the relative percentages of the ingredients. In using the apparatus, the hand wheel 14 is first rotated until the pointer 20 indicates on the scale 21 the total weight of mixture required. The ingredients are then placed successively upon the weighing platform 1 in sufficient quantities to move the pointer 13 over the corresponding ingredient arcs on the formula card R<11>. In an alternative wherein each ingredient is removed after weighing, the formula card R<11> is rotated backwards through one ingredient arc after each weighing, the setting of the card being facilitated by notches in its edges engaging a pawl at the zero of the dial 12. The hand adjustment of the formula card may be avoided by arranging for the formula card to be advanced one ingredient arc by each forward step of the pointer shaft. The platform 1<1> may be utilized in other methods of determining ingredients or may be omitted. In a modification, Figs. 5 and 6 (not shown), duplicate pendulums are provided, the pendulum weights being simultaneously adjusted for the total weight of ingredient required, by means of a hand wheel operating through a system of gearing including a loosemotion arrangement whereby a small backward movement of the hand wheel leaves the pendulums free for counterbalancing the load. A pointer indicates the weight of mixture for which the pendulum weights have been set, and a further pointer (actuated by the angular movements of the pendulums) indicates the percentages. The formula card is of reduced size and its arcs are traversed by a succession of pointers connected by reducing gear to the load-operated pointer. In a further modification, Fig. 7, the percentage dial is built up of a number of coaxial sectors 26 geared together so that they may be fanned out by a manual adjustment so as to cover the desired weighing range. In further modifications, the weight and percentage numerals are arranged in sets on an adjustable dial mounted behind a graduated front dial through apertures in which the appropriate set of numerals may be displayed. The percentage numerals in this case show the ratio of the true weighing range to the weight numerals displayed, the latter being fictitious. In a further modification, Figs. 9 and 10 (not shown), a pointer when set manually to the total weight required, varies also a friction-disc drive between the percentage and weight pointers so as to give the correct percentage indications as the ingredients are added. The arrangement in a modified form, Fig. 14 (not shown) gives readings relating to content values, for example, to albumen and starch in kilos, and nutritive value in thermal units. In a further modification, Fig. 11, an optical indication is provided. The weight on the weighing platform rotates the indicating pointer 52. A gear-wheel 56 on the pointer spindle correspondingly moves a pointer 54 horizontally over a window 58, and a shadow of the pointer is projected by a light source 55 and mirror 59 on to a percentage scale 53 and formula card R displaceably held beneath the percentage scale and marked with parallel ingredient lengths. A masking screen 57 limits the illuminated area to the length of the percentage scale and is adjusted to the correct position according to the total weight of mixture required, by means of gearing connected with the setting indicator 51 movable round the weight-indicating dial. The light source 55 and mirror 59 may be raised or lowered to bring the illuminated area into coincidence with the percentage scale. In'a modification, Fig. 12 (not shown) wherein the positions of the light source and the masking plate (made in pivoted sections) are positively and simultaneously adjusted by mechanical connections with the setting indicator, the percentage reading scale may be slid laterally by rotating a handle, to change the range of its percentage indications and simultaneously to adjust correspondingly the light source and the sections of the masking plate controlling the illumination of the percentage scale. A final adjustment may be made by a manual adjustment of the mirror. All the sections of the masking screen may be moved into an inoperative position by rotation of a hand knob. In a further modification, Fig. 23 (not shown), the weight indications on the dial may be changed simultaneously with the percentage scale readings to a definite percentage of the real weighing range and further sets of numerals on the percentage scale are provided to accommodate different settings of the optical devices. In a further modification of the indicating device, Fig. 13, for use with a formula card R<1>, a moving part of the weighing machine rotates one of two pulleys 91, 911 mounted on stationary screwed spindles 92, 92<1>. The pulleys carry an endless band provided with equally-spaced pointers 90<1> which travel successively over the percentage lines of the formula card as the band is moved. The formula card may be advanced to change to a new-ingredient by a device similar to the arrangement used in typewriters. In a further modification, Fig. 18 (not shown), applied to a spring balance, the weight and percentage pointers move over a circular dial, the percentage pointer being connected to selectively varied points of the weighing springs. By rotating a handle, a setting indicator is moved round the weights dial to indicate the desired weight of mixture, and simultaneously, forked devices in actuating connection with the percentage pointer are moved along the convolutions of the weighing springs to maintain the correct angular movement of the percentage pointer.