Patent GB-1523930-A (GB)
Title: Electromagnetic system for propulsion and programmed positioning
IPC: B66B11/04
Filed: 1975-12-31
Abstract: 1523930 Feeding articles on to conveyer belts; storage systems M BARTHALON 31 Dec 1975 [10 Jan 1975] 53371/75 Headings B8A and B8W [Also in Division G3] An electromagnetic device for removing objects from a container is responsive to signals from an electronic programmable control device. As shown, Fig. 1, a storage section 1, comprising compartments in which objects are stacked vertically, is provided with openings 11, 12 through which the objects are selectively ejected by a ram 3 mounted on a carriage 2. The carriage forms the magnetizing circuits of an electromagnetic device and is guided by a rail 4 carrying magnetic cores 5. The address at which the carriage is to be positioned is set up on a keyboard 22 of a control unit 21 which, on operation of a start button 25, transmits a train of pulses to the magnetizing circuits. In an alternative arrangement, Fig. 4, the containers B are extracted by a device whereby, in response to a sequence control system, not shown, an electro-pneumatic valve 52 is actuated to (1) allow a spring 48 to push forward a bellows 47 carrying a suction element 46 until it engages a container, (2) apply a vacuum from a pump 53 whereby the container is retained by the element and (3) increase the vacuum until the spring is compressed and the container withdrawn from the compartment. In a further arrangement the containers are stacked vertically and the electromagnetic device is arranged to move a compartment transversely to the direction of travel of the conveyer belt. The containers are extracted by a device 96, Fig. 12, comprising a resilient pushrod 148, centrally positioned on the conveyer 95 on a plate 171, pivoted on a support plate 174 to which is bonded a permanent magnet 176. In operation, a stop 177 on the push-rod engages a container and withdraws but, in the event of a jam the flap 174 disengages from the magnet 176 and the device passes under the compartment and is reset as the conveyer belt passes over an end pulley. The magnet 176 and plate 171 extend transversely for approximately half the belt width.  The width and/or length of compartments can be adjusted by an assembly of braces or spacers Figs. 10, 11, not shown.  The electro-magnetic device, Fig. 9, comprises magnetic cores 122 in which the distance Ps between adjacent cores is different from the distance between the poles Pc of two consecutive magnetizing circuits 115 in the relationship where n is the number of circuits and the figure K = 1 and n = 4.  In an alternative arrangement of the electromagnetic device the magnetized portion is constituted by iron or mild steel sheets cut out to form teeth which are magnetized by pairs of coils supplied with programmed pulses. The formula then relates to the pitches of successive teeth.  The automatic control of stock distribution and the semi-automatic replenishment, in a system comprising a movable container and extractors on a conveyer, Fig. 15, comprises a console 221, having a keyboard 225 which provides position commands through a coder 222, as modified by a device 223, and memory 224 to a sequential logic circuit 228. A start-up command is sent from the console over a line 230 to the logic circuit 228 which controls a power switch 232 producing power pulses to energize coils 236 of the electromagnetic device of the extractor, a timer 237 limits the operating timer of the device to a safe value. The logic circuit 228 also energizes a contactor 241 for a conveyer 242 and a detector 243 responds to the passage of an object extracted. Information set in by keyboard 225, and secondary keyboards 226, 227, can be displayed, through an interface 251, by a printer 250. Replenishment of containers is effected manually by an operator preventing the operation of the extractor by a key 260 and employing a manual button 261 for initiating reclosure of the container.