Patent GB-436240-A (GB)
Title: An improved machine for grading or sorting by weight
IPC: B07C5/18
Filed: 1934-05-18
Abstract: 436,240. Sorting by weighing. AVERY, Ltd., W. & T., and JONES, W., Soho Foundry, Birmingham. May 18, 1934, Nos. 14978 and 27449. [Class 143] A machine for grading or sorting by weight comprises a load-receiving device, an automatic weighing resistant, an electric circuit control means operable solely under the influence of the load and assuming a circuit completing condition when a load is applied to the receiving device, electrically controlled means for ensuring the maintenance of the load on the receiving device until a weighing operation has been performed electrically operated deflector mechanism capable of being brought into operation subsequent to the completion of a weighing operation, and electrically influenced means for maintaining the deflector mechanism active (if in operation), for a period of time necessary to ensure the transfer of the load from the receiving device and the restoration of the mechanism to the initial position. As applied to the sorting of tinplates an inclined weighing platform 10 supported on a weighbeam 12 receives the tin-plates singly from a feed platform (not shown). The weighbeam carries a pendulous weight 15 adjustable along a screw by means of a key. In operation, the accuracy of the machine is tested by placing a known weight on the weighing platform and adjusting the pendulous weight 15 until a dial 50 rotated by the movement of the pendulous weight indicates this known weight. A pointer 46<a> carried by the weighbeam should then indicate zero against a scale 53. The known weight is removed and two electric switches 32<1>, 33 at opposite sides of a contact 32<a> carried by the beam are then adjusted horizontally by keys to set the maximum percentage of under and over weight allowed, the positions of the switches being indicated on scales 43<a>, 43<b>. The tin-plates are now fed singly to the feed platform (not shown), and after temporary retention thereon by electromagnets slide onto the weighing platform 10 where they abut against a pivoted flap 55. The weight of the tin-plate depresses a platform switch 16 thereby de-energizing a centralizing solenoid 18, a beam-locking solenoid 17 and a delay action solenoid. The weighing operation takes place and at the same time three mercury switch tubes liberated by the delay action solenoid tilt in order to complete further circuits, the tilting being retarded by an air dash-pot to allow sufficient time for the weighing operation to be completed. The circuits of the mercury switch tubes then cause (1) the locking solenoid 17 to attract a flexible arm 32 on the weighbeam and lock the same, (2) a solenoid to unlatch the stop flap 55 and allow the tin-plate to slide off the platform, and (3) de-energize the electromagnets holding the next plate on the feed platform. If the tin-plate is of under or over weight the contact-closing member 32a engages one or other of the contacts 32<1>, 33 and by means of solenoids raises one or other of two deflectors 27, 28 to direct the tin-plate to an under or over weight receptacle. Tin-plates of correct weight fail to close either of the contacts 32<1>, 33, and pass straight forward to a correct weight receptacle. The removal of the tin-plate allows the platform switch 16 to close and energize the solenoid 18. The armature of this solenoid positions the beam in central position and re-energizes the locking solenoid 17 to lock the beam.