Improvements in and relating to dial devices for scales or the like for disengaging and automatically restoring the pointer to a predetermined position

摘要

732,214. Weighing apparatus. SOC. PER AZIONI ATOMA. Oct, 14, 1953 [Oct. 14, 1952], No. 28354/53. Class 143. The invention relates to a specific arrangement of mechanically clutching a pointer to a rotating member to obtain taring. When an empty container is placed on the scale pan, the shaft 10, Fig. 2 rotates, thus rotating pointer 16, Figs. 1 and 2, over a fixed scale 20, and with a scale 24 which is rigid with shaft 10. Lever 66, Fig. 4, is now depressed, and through the pivoted link 64 causes lever 60 to move downwards about pivot 62, so that the jaws 56 press arms 46 together, the tips 42, Figs. 2, 3 closing to move disc 38 in the direction of arrow Z, Fig. 2, thus relieving the pressure on springs 30 and de-coupling the pointer from shaft 10. Arms 44, Fig. 3, are coupled by compression springs 45 to arms 50 which are held apart by springs 55, so that as arms 44 close, arms 50 also close, their tips 54, Fig. 2, gripping disc 34 keyed to shaft 10 and thus preventing shaft 10 from rotating. Further depression of lever 66 now causes link 72, Fig. 4, to engage a pin 75 on lever 76 which moves downwards about pivot 78; the end 82 of lever 76 is thus depressed to engage a cam 26 rigid with the pointer 16 and thus restore the cam and pointer to the original position, the dial 24 remaining stationary in the position corresponding to the weight of the empty container. Lever 66 is now released, and the empty container is filled or replaced by a filled one; the pointer 16 then indicates the net weight on scale 20 and the tare weight on scale 24.