Telephonic communications – Call or terminal access alarm or control – At substation
Patent
1987-02-04
1989-05-23
Dwyer, James L.
Telephonic communications
Call or terminal access alarm or control
At substation
379188, H04M 166
Patent
active
048337072
ABSTRACT:
A telephone lock unit having two selectable locking modes will limit (a) all long distance and operator cell connections or (b) all local, long distance and operator call connections to all persons other then those implementing the correct access code onto the telephone dial or keypad. The unit operates in conjunction with conventional pulse and tone dialing type telephones while being of a self contained electronic design. The access code which may contain 3 or 4 digits can be programmed by any authorized person by means of an internal matrix switch. A save and relock function allows any authorized person knowing the correct save and relock code the option of disabling and reinstating the locking mode function. The locking mode functions are performed electrically by momentarily disconnecting the telephone from the telephone line causing the re-occurrence of the dial tone, thus canceling all previous call atempts. The unit contains an interface circuit and while in compliance with FCC part 68 rules and regulations enables the locking of one or more telephones when are so connected to the same telephone line via a single telephone lock unit. All circuit functions are performed while the telephone and telephone lock unit are operating in a closed loop condition with the central office.
REFERENCES:
patent: 4022992 (1977-05-01), Kennedy
patent: 4099033 (1978-07-01), Murray
patent: 4234764 (1980-11-01), Beebe
patent: 4314108 (1982-02-01), Sharvit
patent: 4358640 (1982-11-01), Murray
patent: 4425480 (1984-01-01), Lischin
patent: 4482787 (1984-11-01), Sagara
patent: 4511765 (1985-04-01), Kuo
Dwyer James L.
Serret Systems Inc.
LandOfFree
Telephone lock unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Telephone lock unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Telephone lock unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1735938