Telephone security device

Claim 2

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; and g. switch means are arranged to control the magnitude of the said predetermined count, and to permit variation of the said magnitude; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number.

Claim 3

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; g. a battery provided inside the housing; h. a transistor switch disposed inside the housing; i. a connection from the battery to bias that transistor switch to a conductive condition; and j. a further connection by which a line voltage appearing on the said connecting means is arranged to bias that transistor switch to a non-conductive condition; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number and whereby when a cradle switch of the telephone set closes, the consequent fall in the said line voltage permits the said battery to make the transistor switch conductive so energizing the group-pulse counting means.

Claim 4

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; g. a battery provided inside the housing; h. a transistor switch disposed inside the housing; i. a connection from the battery to bias that transistor switch to a conductive condition; and j. a further connection by which a line voltage appearing on the said connecting means is arranged to bias that transistor switch to a non-conductive condition; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number and whereby when a cradle switch of the telephone set closes, the consequent fall in the said line voltage permits the said battery to make the transistor switch conductive so energizing the group-pulse counting means.

Claim 5

The security device according to claim 2, and in which a diode is arranged normally to supply from the line voltage a charging current to the said battery.

Claim 6

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; g. a switch arranged to shunt the connecting means carrying dialed pulses from a signalling dial of the telephone set, this switch forming part of the said call aborting means; and h. this switch being effective when a call is to be aborted to attenuate those pulses so severely as to render them ineffective; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number.

Claim 7

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; g. a switch arranged to shunt the connecting means carrying dialed pulses from a signalling dial of the telephone set, this switch forming part of the said call aborting means; and h. this switch being effective when a call is to be aborted to attenuate those pulses so severely as to render them ineffective; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number.

Claim 8

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective trans-mission of dialing pulses once the group-pulse counting means has reached a predetermined count; and g. a further switch associated with the call aborting means and arranged by its actuation to render the call aborting means effective, even before any pulses are received; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number and whereby upon operation of the said further switch, no digits can effectively be dialed on the dial-type telephone set.

Claim 9

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective trans-mission of dialing pulses once the group-pulse counting means has reached a predetermined count; and g. a further switch associated with the call aborting means and arranged by its actuation to render the call aborting means effective, even before any pulses are received; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number and whereby upon operation of the said further switch, no digits can effectively be dialed on the dial-type telephone set.

Claim 10

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; and g. a rotary lock on the housing provided with a key, said lock having a plurality of positions at each of which said key to the lock can be removed, and the setting of the security device as regards the calls which can be made from the said telephone set is controlled by the selected position of the lock at the time when said key is removed; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number.

Claim 11

A security device suitable for use with a dial-type telephone set, and comprising: a. a housing; b. electronic circuitry inside that housing; c. connecting means extending from the electronic circuitry and adapted for the connection of the circuitry to terminals carrying dialed pulses from the telephone set; d. pulse grouping means included in the said circuitry and adapted to transform groups of received separate dialing pulses each into a group pulse by distinguishing between inter-pulse timing periods and inter-group timing periods; e. group-pulse counting means arranged to receive and to count the said group pulses; f. call aborting means arranged to be sensitive to the count in the said group-pulse counting means and to prevent the effective transmission of dialing pulses once the group-pulse counting means has reached a predetermined count; and g. a rotary lock on the housing provided with a key, said lock having a plurality of positions at each of which said key to the lock can be removed, and the setting of the security device as regards the calls which can be made from the said telephone set is controlled by the selected position of the lock at the time when said key is removed; whereby the security device is effective to restrict the use of the dial-type telephone set to the effective dialing of a series of digits no greater in number than a predetermined number.

Claim 12

The security device according to claim 6, and in which an access cover is provided on the housing, and the rotary lock has a further position to which the lock key can be set, and only when the key is set to that position can the access cover be removed.