Patent GB-1051914-A (GB)
IPC: G01G13/14
Abstract: 1,051,914. Weighing apparatus. OLOFSSON CORPORATION. Sept. 10, 1963 [Oct. 17, 1962], No.35736/63. Heading G1W. Relates to weighing apparatus associated with a packaging plant, wherein a plurality of weigh receptacles 23 (Fig. 2), each supported by a separate weigh beam unit, travel in an endless path during one traverse of which each weigh beam is automatically balanced to compensate for tare weight of an empty receptacle, a receptacle is filled to more than a predetermined weight, weighed and vibrated to trim off surplus material and finally discharged into a chute hopper and from thence to a carton if the weight is correct. CASCADE FEED ARRG'T (FIG. 5) Material falls from a hopper 31 to a trough 103 which is vibrated by a vibrator 101 so that trough 103 feeds to a second trough 107 which is balanced on a beam. If the feed rate to 107 is insufficient to keep the beam balanced a relay is energized to cut out a resistance (servo motor driven cheostat) in circuit with the vibrator 101 and thereby increases the vibration rate - Similarly a vibrator 110 is mounted on the trough 107 and this trough feeds a third through 127, which is similarly vibrated and mounted on a balance beam to control the feed rate of the second. The vibration rate of trough 127 is controlled by a signal from the weighing apparatus during the trim off operation on the weigh receptacle load. WEIGH RECEPTACLE - (FIG. 8.) The weigh receptacles 23 are generally as Specification 907, 617 and each has a large capacity pan 27 and a smaller capacity vibratory tray 28 which is vibrated to trim off excess weight, during rotation of the apparatus, by means of electromagnetic vibrators 151, 152, the tray 28 being supported on leaf springs. Both the pan 27 and the tray 28 are carried by an inverted U saddle straddling the side walls of a housing 94 of a weigh beam unit 93. WEIGHER ASSEMBLY - (FIG. 12) FIGS. 9 & 11 (not shown) A weigh beam 170 is fulcrummed by means of bearings 171 and trunnions 172 on the walls of housing 94 - Tare adjustment - To zeroize the weigh beam and compensate for material adhering to a receptacle after a previous discharge an eccentric tare counterbalance weight 177 is provided on the beam and is rotatably adjusted by means of a motor 175 driving a shaft 176 connected through gears to the tare counterweight. The weigh beam also carries in an annular circular recess 192 therein a cylindrical master counterweight 193 to exactly balance the target weight value of a filled receptacle 23, and is relieved of the counterweight 193, during tare adjustment, by means of an unseating rod 197. A tungsten wire element 185 also in Fig. 24A (not shown) extending from the beam breaks contact with a contact wire 186 when material adheres to the receptacle after discharge thereby energizing the motor 175 to adjust the tare weight 177 position. During weighing, if the load is overweight the wire 185 engages a contact 187; if the load is at an acceptable weight neither of the contacts 186, 187 are engaged by the wire 185, and if underweight the contact 186 is engaged by the wire 185. A leaf spring 215 secured to the housing wall bears down on the beam 170 to effect a certain beam position for any condition of balance. Stops 222 engaging a finger 221 on the beam limits the beam travel. An oil dash pot damper is provided for the beam. Each weigher assembly is carried by a cantilever arm 72 radially extending from a circular casting 69 secured to a hub 62 (Fig. 4) driven by a shaft 54. The arms 72 also support discharge funnels and pushers to push the cartons to be filled along a conveyer Fig. 1 (not shown). DISCHARGE OF RECEPTACLES - (FIG, 4) The shaft 54 carries a circular cam plate 85 having a downwardly opening cam groove 86. This groove receives a follower roller 88 of each of a series of pivotted link arms 89, one for each receptacle. These arms control the tilting of a receptacle for the discharge thereof into a funnel hopper 22. UNDERWEIGHT AND OVERWEIGHT REJECTION - (FIG. 4) Surrounding the shaft 54 is a memory disc 63 having near its periphery a plurality of circumfer - entially spaced pins 64, one for each weigh receptacle 23, arranged to be shifted upward by a solenoid 59 on receipt of a signal indicating under or overweight in any receptacle following the trimming operation - A limit switch Fig. 4a (not shown) is actuated by the memory pins, when the pins reach a predetermined point in their rotary path, causing a further signal to be sent to a mechanism (not shown) which causes a carton conveying machine not to set up a carton. This operation is synchronized with the travel of a filling funnel 22. Fig. 19 (not shown). Conveyers 33, 37 are provided to return trimmed off and incorrect weight material to the feeder mechanism.