GB1255406A - A warehousing system - Google Patents

Abstract

1,255,406. Subtracting circuits; selective signalling. CONCO Inc. 20 May, 1969 [26 March, 1969], No. 25712/69. Headings G4A and G4H. In a system for automatically positioning the load moving device 36, Fig. 1, of an automatic warehouse system, photo-electrically derived 55 (see also Fig. 3) signals P, Fig. 4, representing the position of the device are subtracted, in parallel, from command signals C representing the desired position of the device, and when the device is at a certain distance from its desired position its speed is reduced until the desired position is reached when it is stopped. Binary-coded decimal signals representing the actual position of the device are produced by photo-electric cells 61, Fig. 3, carried by the device, light to these cells from lamps 60, also carried by the device, being interrupted by a pattern of plates 55. A further plate 70 carrying a reflective strip 74 is provided to produce a pulse in a combined lamp and cell 72 when the device is in such a position that the cells 61 produce meaningful signals. Parallel subtraction of the position signals P from the command signals C is effected by a relay circuit, Fig. 5, in which only the circuit for bits " 1 " and " 2 " is shown in detail. The numbers C and P are registered on relays HC1, HC2, HC4, ... , and HP1, HP2, HP4, ... , not shown. In the circuit for the " 2 " bit, a relay D2 is controlled to indicate the result for that bit, and a relay B2 to indicate whether any " borrowing " is necessary from the next higher stage. Thus, the circuit for the " 2 " bit includes contacts of a relay B1 which is energized if the " 1 " bit stage has to borrow.