Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
217 words
A prepayment system for a metered commodity comprising a receptacle (12) for a key (10), the receptacle (12) having a circuit (14) for reading data from a memory in a key (10) inserted in the receptacle (12), and for allowing access to the commodity only when authorised by predetermined authorizing data read from a key memory, characterised in that the circuit (14) tests data read from a key memory to determine if the data is authorising data which is unique to the receptacle (12) and the corresponding key (10) and which includes a code specifying the quantity of metered commodity to which access is allowed, and in that the receptacle circuit (14) includes a receptacle memory (16) which responds to the first insertion of a key (10) to store data representing the said quantity in association with data identifying the key (10), and responds to each subsequent insertion of the key (10) corresponding to the identifying data and/or to an insertion of the said key (10) lasting in excess of a predetermined time, both to modify the quantity in the receptacle memory (16) so as to decrement the quantity by a predetermined amount and to set or to permit the setting of a metering device (18) to allow access to the predetermined amount of the metered commodity.
Claim 2
Dependent Claim
217 words
A prepayment system for a metered commodity comprising a receptacle (12) for a key (10), the receptacle (12) having a circuit (14) for reading data from a memory in a key (10) inserted in the receptacle (12), and for allowing access to the commodity only when authorised by predetermined authorizing data read from a key memory, characterised in that the circuit (14) tests data read from a key memory to determine if the data is authorising data which is unique to the receptacle (12) and the corresponding key (10) and which includes a code specifying the quantity of metered commodity to which access is allowed, and in that the receptacle circuit (14) includes a receptacle memory (16) which responds to the first insertion of a key (10) to store data representing the said quantity in association with data identifying the key (10), and responds to each subsequent insertion of the key (10) corresponding to the identifying data and/or to an insertion of the said key (10) lasting in excess of a predetermined time, both to modify the quantity in the receptacle memory (16) so as to decrement the quantity by a predetermined amount and to set or to permit the setting of a metering device (18) to allow access to the predetermined amount of the metered commodity.
Claim 3
Dependent Claim
18 words
A system according to claim 1, wherein the receptacle (12) does not write data into a key memory.
Claim 4
Dependent Claim
47 words
A system according to claim 1 or 2, characterised in that the system also responds to the first insertion of a key (10) lasting less than the said predetermined time as it does to subsequent insertions and/or to an insertion lasting in excess of the predetermined time.
Claim 5
Independent Claim
27 words
A system according to any preceding claim, characterised in that the receptacle circuit (14) is adapted to read data from a key (10) having a semiconductor memory.
Claim 6
Independent Claim
84 words
A system according to any preceding claim, characterised in that the receptacle circuit (14) reads data from the memory of a key (10) in the receptacle (12), including data identifying the key (10), data identifying the receptacle (12), and pass number data, and in that the receptacle circuit (14) allows access to the commodity when the pass data read from the key (10) is related in a predetermined way to data representing pass data, which has been previously stored by the receptacle circuit (14).
Claim 7
Independent Claim
74 words
A system according to any preceding claim, characterised in that the receptacle circuit (14) reads data from the memory of a key (10) in the receptacle (12), including data identifying the key (10), data identifying the receptacle (12), and pass number data, and in that access to the commodity is allowed when the pass data read from the key (10) is related in a predetermined way to other data read from the key (10).
Claim 8
Independent Claim
20 words
A system according to any preceding claim, characterised by comprising a key (10) having a memory for storing authorizing data.
Claim 9
Dependent Claim
141 words
A security system for use in a prepayment system for a metered commodity, the system comprising a receptacle for a key, and a circuit for reading data from a key in the receptacle, and being characterised in that a memory in a key (10) stores identifying data and quantity data specifying the quantity of the commodity to which access is allowed, and in that the system comprises a receptacle circuit (14) for processing identifying data read from a memory in a key (10) in the receptacle (12) and data read from a memory in the receptacle circuit (14) to test the validity of the key (10) and to detect the first insertion of a valid key (10), the receptacle circuit (14) being operative to store data representing the data read from the key (10) only on the occasion of such detection.
Claim 10
Dependent Claim
141 words
A security system for use in a prepayment system for a metered commodity, the system comprising a receptacle for a key, and a circuit for reading data from a key in the receptacle, and being characterised in that a memory in a key (10) stores identifying data and quantity data specifying the quantity of the commodity to which access is allowed, and in that the system comprises a receptacle circuit (14) for processing identifying data read from a memory in a key (10) in the receptacle (12) and data read from a memory in the receptacle circuit (14) to test the validity of the key (10) and to detect the first insertion of a valid key (10), the receptacle circuit (14) being operative to store data representing the data read from the key (10) only on the occasion of such detection.
Claim 11
Dependent Claim
70 words
A system according to claim 8, characterised in that the identifying data includes data identifying the key (10), data identifying the receptacle (12), and pass number data, and in that the first insertion of a valid key (10) is detected when the pass data read from a key (10) is related in a predetermined way to data representing pass data, which has been previously stored by the receptacle circuit (14).
Claim 12
Dependent Claim
65 words
A system according to claim 8 or 9, characterised in that the identifying data includes data identifying the key (10), data identifying the receptacle (12), and pass number data, and in that the first insertion of a valid key (10) is detected when the pass data read from the key (10) is related in a predetermined way to other data read from the key (10).
Claim 13
Dependent Claim
141 words
A prepayment system for a metered commodity comprising a key (10) with a memory, and a receptacle (12) for the key (10) with a circuit (14) for allowing access to the commodity only when authorised by predetermined data in the key memory, characterised in that the data in the key memory is unique to the key (10) and to the corresponding receptacle (12) and includes a code specifying the quantity of the metered commodity to which access is allowed, and pass number data, and in that the receptacle circuit (14) includes a receptacle memory (16) which tests the pass number data stored in the key (10) to detect the first insertion of the key (10), and responds only to the first insertion of the key (10) to store data representing the said quantity in association with data identifying the key (10).
Claim 14
Dependent Claim
141 words
A prepayment system for a metered commodity comprising a key (10) with a memory, and a receptacle (12) for the key (10) with a circuit (14) for allowing access to the commodity only when authorised by predetermined data in the key memory, characterised in that the data in the key memory is unique to the key (10) and to the corresponding receptacle (12) and includes a code specifying the quantity of the metered commodity to which access is allowed, and pass number data, and in that the receptacle circuit (14) includes a receptacle memory (16) which tests the pass number data stored in the key (10) to detect the first insertion of the key (10), and responds only to the first insertion of the key (10) to store data representing the said quantity in association with data identifying the key (10).
Claim 15
Dependent Claim
51 words
A system according to claim 11, characterised in that the receptacle circuit (14) detects the first insertion of the key (10) when the pass data read from the key (10) is related in a predetermined way to data representing pass data, which has been previously stored by the receptacle circuit (14).
Claim 16
Dependent Claim
84 words
A system according to claim 11 or 12, characterised in that the receptacle circuit (14) responds to each subsequent insertion of the key (10) corresponding to the identifying data and/or to an insertion of the said key lasting in excess of a predetermined time, both to modify the quantity data so as to decrement the quantity by a predetermined amount and to set or to permit the setting of a metering device (18) to allow access to the predetermined amount of the metered commodity.
Claim 17
Dependent Claim
44 words
A system according to claim 3, characterised in that the system also responds to the first insertion of the key (10) lasting less than the predetermined time as it does to subsequent insertions and/or to an insertion lasting in excess of the predetermined time.
Claim 18
Independent Claim
24 words
A system according to any of claims 11 to 14, characterised in that the receptacle (12) does not write data into the key memory.
Claim 19
Independent Claim
20 words
A system according to any of claims 11 to 15, characterised in that the key memory is a semiconductor memory.
Claim 20
Independent Claim
48 words
A system according to any of claims 11 to 16, characterised in that the receptacle circuit (14) detects the first insertion of the key (10) when the pass data read from the key (10) is related in a predetermined way to other data read from the key (10).
Claim 21
Independent Claim
26 words
A system according to any of claims 6 to 10 and 17, characterised in that the said other data is the data identifying the key (10).