Patent GB-1320630-A (GB)
Title: Card reader monitoring system for controlling the delivery of  liquid products
IPC: G07F7/02
Filed: 1971-05-28
Abstract: 1320630 Card freed fluid dispensers L'ELECTRONIQUE APPLIQUEE 28 May 1971 [28 May 1970 21 April 1971] 17924/71 Heading G4V A card freed system for dispensing fluid products comprises a card reader 7, which reads from a presented card 1 information concerning the nature of a fluid product and the quantity of that product which may be dispensed to the customer, means 12, 13 for forming electrical representations of the read information, a plurality of delivery stations each of which has an associated delivery control circuit 24 to 27 that includes means for forming electrical representations of the nature and quantity of the product requested by the customer, and comparator means for comparing the electrical representations as derived from the card reader and each delivery control circuit and activating the corresponding delivery station in the event of a favourable comparison. The information on the card is arranged to be read in steps, each step corresponding to a particular type and quantity of product, and a comparison with the requested type and quantity is made at each step. In this way the customer is authorized by the card to take a variety of deliveries at a free choice of delivery stations. Card reader.-The card which is of punched form is held stationary and is traversed stepwise by two independently movable photo-cell equipped reading heads 8 and 10 traversing zones 2 and 3 of the card respectively. The heads are driven by endless screws 9, 11 the rotations of which are controlled by electromagnetic clutches and brakes (51) to (53) (Fig. 2, not shown). The head 10 is driven at twice the speed of head 8 since the information relating to the quantity of the product in zone 3 of the card requires twice as many columns as the product type information in zone 2. Timing perforations 6 are also included in the zone 2 which are read by an additional photo-cell in the head 8. Delivery control circuit.-Each delivery control circuit includes means such as resistors 36, 37 and switches e.g. as at 38 which may be selectively connected to earth or a supply line AL by the customer to produce an analogue representation of the product type and quantity required. This may also be achieved by connection of the control circuit to encoders 40 on the tank 41 or 42 to be filled. Analogue representations of the product type and quantity codes read at that step of the card are supplied from the registers 12, 13 to each of the control circuits through gates 16, 19 and the control circuits are then interrogated in sequence to determine if the two analogue representations are identical in any circuit. If identity is found in any circuit then the corresponding delivery station is activated to control the delivery of the product by unblocking the supply electro-valve 30 thereof. The delivery of certain types of product, such as petrol, may require that the tank is earthed and a sensor is provided in the control circuit to determine whether this condition is met. If on interrogation the necessary conditions are not met in any control circuit the card reader is stepped forward and the next read type and quantity codes are compared with contents of the control circuits. Dispensing arrangements.-If the tank as at 41 is to be filledin a "vault-like" mode a fiowmeter 32  is provided, the quantity dispensed being compared in a comparator 33 with the quantity code read from the card. The reading head may either be held stationary during dispensation to ensure that the contents of register 13 do not change or alternatively an additional memory device may be provided to store the contents of register 13 during dispensation. If the tank as at 42 is to be filled in a "spring-like" mode level sensors 43, 44, 45 in the tank may be provided to control the quantity and rate of dispensation of the product.