Patent GB-1364445-A (GB)
Title: Calculating systems
IPC: G07B15/04
Filed: 1970-11-11
Abstract: 1364445 Systems for determining use made of a facility; car parks; change giving GODWIN WARREN ENG Ltd 27 Oct 1971 [11 Nov 1970] 53718/70 Headings G4T and G4V To determine the use made of a facility, a user is allocated a group of symbols (e.g. a number), which relates to the commencement of his use of the facility but is encoded to conceal from the user its relationship with such commencement, and when the user wishes to stop using the facility, he (or a supervisor) enters the group, symbol by symbol, via a keyboard into apparatus which determines from the entered group the use made of the facility and/or the fee to be paid for such use. Because of the concealed relationship, the user risks being charged more than he need pay if he attempts to defraud the system by entering a group of symbols other than that group allocated to him. When the invention is applied to one man buses, the fee is determined according to the number of fare stages in the user's journey. Alternatively, the fee may depend on the duration of the use of the facility, as in the case of the system shown, which computes car park charges. On entering the car park, the user receives a ticket bearing a four digit decimal number (a coded representation of the time of entry). To leave the car park, this number is entered at keyboard 11, converted at 21 to BCD and stored at 22. The number stored is re-encoded at 28 for display at 30 (for the user to check). The first of the four decimal digits is a parity check digit and is, together with the second digit, checked at circuit 24, which disables circuit 25 if parity is not found. If parity is found, then, when circuit 23 detects entry of the last of the four digits, circuit 25 is enabled to pass pulses from an oscillator 33 to a counter 34 and to the store 22 to increase the stored number until it equals the number from a clock 12, representing the present time. Upon reaching such equality, comparator 27 pulses stop circuit 35 to inhibit circuit 25 and thus the trains of pulses. The count in counter 34 is converted to fee units at 36, the fee being displayed at 13. Alternatively, if during the passing of pulses from oscillator 33, the number of fee units registered at 36 reaches a predetermined maximum fee, then a signal on line 39 inhibits circuit 25 before the number stored at 22 has equalled the number from clock 12. Money is entered at 14 and registered at 40 and 41. When the number of money units held in register 41 is equal to or greater than the number of fee units held at 36, a comparator 42 transmits a signal on line 15 to open the car park barrier. This signal also opens a gate 43 to allow pulses from 43 to increase the count at 45 and decrease to zero the count at 40, the count at 45 thereby being increased by the number of units paid. If the units paid exceed the fee, comparator 42 causes a change giver 16 to dispense units of change, with corresponding subtractions being made from the money paid register 40, until the latter holds a number equal to the fee. Change units dispensed are recorded at 46 and are subtracted from a counter 47, which switches on a warning light when change runs low. In a modification, the signal on line 15, instead of opening the barrier, is used to cause the user's number to be stored for a predetermined period. The user then drives to an exit barrier, where he again enters his number via a further keyboard, which is connected to the system. If the predetermined period has not expired, then the barrier opens without further payment.