GB1340035A - Weighing scales - Google Patents

Abstract

1340035 Weighing apparatus HOLLANDS & BLAIR Ltd 5 Jan 1971 [5 Jan 19701 369/70 Heading G1W A weighing scale comprises (a) a load platform (not shown) overlying a base 10 formed with a perimeter wall 11 having substantially circular holes 22 therein (b) a system of levers 12, 13, 17, 18 engaging bearing surfaces 21 of the holes 22, the platform and weight indicating means 16, all of the pivot axes of the levers being parallel to one another to the base and to the sides 14, 19 of wall 11, and (c) a spring 27 operably connected to the indicating means and to the levers so that it is extended in accordance with a weight loading on the platform. The levers are formed of steel strip with inverted V-shaped apertures 20 to engage the holes 22 and lugs 24 to retain them, levers 12, 13 have the levers 17, 18 pivoted to them at 51, are fixed to a plate 25 and have inverted V-shaped apertures 34 engaging knife edges 33 upstanding from a calibration plate 31, the upper end 30 of the spring 27 is held in a slot 29 in a rod 28 extending upwardly from the base 10 through the centre of the spring 27 which is threaded into the plate 31 and located by dimples 53. In operation when the platform is loaded the levers bear on the plate 31 tensioning the spring 27 which remains vertical and tilting of the plate 25 drives a rotatable scale through rack and pinion. The effective length of the spring 27 may be adjusted by rotating the rod 28 and spring 27 relative to plate 31. The rod 28 is composed of two parts threaded into one another, the lower part having a wheel 59 which may be turned to set the scale to zero.