GB957195A - Apparatus for the setting of the correct weight on a dial scale - Google Patents

Abstract

957,195. Weighing apparatus. VERWALTUNGSGESELLSCHAFT DER WERKZEUGMASCHINENFABRIK OERLIKON A.G. June 24, 1960 [June 27, 1959], No. 22287/60. Heading G1W. An adjustable arm 8, carrying a signalling device (such as the lamp and photo-cell combination 10,11) which is actuated when the pointer 12 of a weighing machine reaches a predetermined position on a dial 9, is set to the required position by a series of planetary or like addition gears controlled by cams driven by a driving shaft 13 to which the cams may be locked in response to an electrical control device. Each of the three planetary gears 22a, 25a, 22b and 22c, 25c is associated with one digit of a three-digit numerical value for the setting of arm 8 on the dial 9 and the gears are connected in series so that the shaft 7 carrying the arm 8 rotates to the appropriate extent in dependence upon the independently controlled rotations of the individual gears. The first cam 16a, when rotated by the driving shaft 13, drives through pinion 20a a drive gear 21a for the first planetary gear. The drive gear 21a carries the stem 24a of the planet pinion 25a whose sun pinion is freely rotatable on shaft 5. A gear 26a integral with the planet pinion drives a gear 27a integral with the sun pinion 22b of the next planetary gear. The succeeding planetary gears are driven and interconnected in like manner, the coupling be- . tween adjacent gears bearing a ratio of 10 : 1 and the whole gear train driving the adjusting shaft 7 by means of the coupling 26c-27c. A spiral spring or other resistant may oppose the motion of this shaft in order to neutralise gear play. Each of the cams 16a, 16b, 16c driving one of the planetary gears is clutched to the drive shaft 13 by a spring-urged plate 17a, b or c, each plate 17 being connected through a spring 18 to a plate 19 keyed to the shaft. A notch 28 in the periphery of each cam 16 may be engaged by a solenoid operated plunger (not shown) so that the cam rotates only when its plunger is withdrawn. Information presented to the control circuit (not shown) in digital form, e.g. on punched cards or by keys, is made to withdraw the plunger solenoid of each cam for a sufficient number of revolutions of the drive shaft 13 to cause the correct rotation of the adjusting shaft 7 in accordance with the corresponding digit of the required setting. Switches 33 co-operating with lugs 32 on the cams signal each rotation thereof to the control circuit. For resetting the arm 8 to zero, the motor 15 driving the shaft 13 may be reversed and switches 35 operated by lugs 34 carried by the drive gear of each sun pinion provide signals to the control circuit when each of the said pinions are at their zero setting. These signals control the cam unlocking during the reset operation and the switch-operating lugs 34 are so profiled that they are only effective during the reverse motion of the drive shaft.