Patent GB-736109-A (GB)
Title: Material handling and weight totalizing systems
IPC: G01G19/00
Filed: 1953-01-15
Abstract: 736,109. Weighing apparatus. ATLAS BOLT &'SCREW CO. Jan. 15, 1953 [Jan. 23, 1952], No. 1233/53. Class 143. [Also in Groups XIX and XXXVIII] Material is dispensed from a plurality of storage containers into a hopper fixedly located or traversable between the various containers and a dumping station, e.g. for charging blast furnaces with coke, limestone, iron ore &c. and the hopper has a weighing mechanism and a plurality of counters, one for each container, for totalizing the total weight of material supplied from each container over a period. To this end a selector switch 158 is manually operated to energize and couple a driving motor to the corresponding counter and this operates until a follow-up member 72, also driven by the motor, is in alignment with the weighing scale indicator 23 whereupon a micro-switch 110 on the follow-up member 72 is closed and through a relay disconnects the current supply to the motor. As shown (Fig. 3) the hopper and its load rotate a weighing scale indicator 23 through a rack and pinion 19, 21 and the indicator shaft 22 also rotates a pointing wheel 26 with type figures on its periphery for recording weights and with a tripper member 111 which closes the contacts of a micro switch 110 mounted on the end of a follower arm 72 but only when the latter and the scale indicator 23 are in alignment. When the hopper is loaded to the required weight by a material the "record" push switch 166 (Fig. 10) is pushed down by the operator so energizing the relay 167 and a motor 40, and the relay 167 is maintained closed by a holding circuit comprising the contact arm 167b and the normally closed contact arm 146b of a relay 146 in series with the micro-switch 110 and hence normally de-energized. Since previously the selector switch 158 has been rotated by the operator to a position 160, 160a or 160b corresponding to the particular material loaded, the corresponding solenoid 105, 105a or 105b is energized causing its armature to push two conical clutch members together and drive the corresponding counter from the motor 40. The drive is maintained till the follower 72 regains alignment with the scale indicator and tripper 111 whereupon the circuit of the relay 145 is energized and hence the holding circuit of the relay 167 is broken and the'motor 40 stops. This pulling up of the relay 145 at the same time causes energization of the brake solenoid 120 so that its armature pushes a spring-controlled and adjustable pawl 114 into engagement with a ratchet driven by the motor 40. The driven counter is therefore immediately braked; but over-run of the motor due to inertia is permitted by a slip clutch between the motor 40 and the driven brake ratchet. This braking of the counters is positively maintained so long as the scale indicator and follow up are in alignment. The process is repeated for each material in turn. To discharge the hopper the selector is rotated to a dumping position 160P so energizing a solenoid 181 pneumatically controlling and releasing the discharge gates. Release of the air pressure at the same time permits the pressureresponsive switch 184 to close contacts 184b so that a solenoid 127 (Figs. 10 and 3) is energized. This acts against spring pressure to release the conical clutch members 61, 63 through which the follower 72 is driven by spur and worm gearing from the drive shaft 43 of the motor 40, and a spiral spring 129 thereupon rotates back the follower 72 to zero position. Shock is avoided to the follower on reaching the zero stop by a spring mounting 131. Selsyns may be coupled to the pointing wheel 26 for remote recording of the weights and materials. Faulty operation, preventing. The weighing carriage can only be moved to another loading station when a power switch 140a is closed by a relay 140 in series with the contacts of a relay 187 and the contacts 146a of the relay 145. The relay 187 is energized only when the selector switch 158 has been rotated to a reset position 160r and is maintained energized by a holding circuit including the contacts 184a of the pressure responsive switch (so that the hopper discharge gates must be closed). Even when the relay 187 is energized the relay 140 is not unless the micro switch 110 is closed (so energizing the relay 146), i.e. the counter must have registered the exact weight. Similarly, at a dumping station the carriage cannot move until the load has been completely dumped (the micro switch 110 will not otherwise be in closed position).