Manhole security cover

A manhole security cover for covering an opening to a manhole, comprising:

• a manhole cover body comprising a non-metallic RF signal transmissive material;
• said manhole cover body having a generally planar first side, a second side spaced from said first side and a peripheral edge portion;
• said manhole cover body being operatively positionable during use thereof to seat on a manhole frame and cover said manhole opening, such that said first side of said manhole cover body is accessible from outside said manhole, said second side of said manhole cover body is disposed within said manhole, and said peripheral edge portion of said manhole cover body engages a manhole cover support surface on said manhole frame;
• a key-actuated latch mechanism operable to engage and lock said manhole cover body to said manhole frame, said latch mechanism comprising one or more latch members on said second side of said cover plate body and a latch drive unit, said latch drive unit being operatively coupled to said latch members and accessible on said first side of said manhole cover body for engagement by a security key;
• a precision mounting insert for installation and latching of said manhole security cover on said manhole frame, said mounting insert comprising a first portion configured to be secured to said manhole frame and to provide said manhole cover support surface, and a second portion recessed from said first portion and comprising one or more control surfaces, including a latching control surface configured to engage said latch members and maintain said manhole cover body in a defined home position relative to said manhole frame;
• a manhole cover tamper sensor on said second side of said manhole cover body, said manhole cover tamper sensor being responsive to a predetermined movement of said manhole security cover body;
• a transmitter operatively connected to said manhole cover tamper sensor and configured to generate a radio frequency manhole cover tamper signal when said manhole cover tamper sensor detects said predetermined movement of said manhole security cover body;
• and
• an antenna operatively coupled to said transmitter to radiate radio frequency energy through said manhole cover body to a receiver located outside of said manhole.

A manhole security cover for covering an opening to a manhole, comprising:

• a manhole cover body comprising a non-metallic RF signal transmissive material;
• said manhole cover body having a generally planar first side, a second side spaced from said first side and a peripheral edge portion;
• said manhole cover body being operatively positionable during use thereof to seat on a manhole frame and cover said manhole opening, such that said first side of said manhole cover body is accessible from outside said manhole, said second side of said manhole cover body is disposed within said manhole, and said peripheral edge portion of said manhole cover body engages a manhole cover support surface on said manhole frame;
• a key-actuated latch mechanism operable to engage and lock said manhole cover body to said manhole frame, said latch mechanism comprising one or more retractable latch members on said second side of said cover plate body and a latch drive unit, said latch drive unit being operatively coupled to said latch members and accessible on said first side of said manhole cover body for engagement by a security key;
• a manhole cover tamper sensor on said second side of said manhole cover body, said manhole cover tamper sensor being responsive to a predetermined movement of said manhole security cover body;
• a latch sensor on said second side of said manhole cover body, said latch sensor being responsive to said latch mechanism being unlatched;
• a transmitter system comprising one or more transmitters, said transmitter system being operatively connected to said manhole cover tamper sensor and configured to generate a radio frequency manhole cover tamper signal when said manhole cover tamper sensor detects said predetermined movement of said manhole security cover body;
• said transmitter system further being operatively connected to said latch sensor and configured to generate a manhole cover unlatching signal when said latch sensor senses said latch mechanism being unlatched;
• an antenna system comprising one or more antennas operatively coupled to said transmitter system to radiate radio frequency energy through said manhole cover body to a receiver located outside of said manhole;
• said manhole cover tamper sensor and said latch sensor supporting a two-stage alert system wherein receipt of said unlatching signal within a predetermined time period prior to receipt of said tamper signal enables a determination of whether removal of said manhole security cover from said manhole opening is authorized or unauthorized.

A manhole security cover for covering an opening to a manhole, comprising:

• a manhole cover body comprising a non-metallic RF signal transmissive material;
• said manhole cover body having a generally planar first side, a second side spaced from said first side and a peripheral edge portion;
• said manhole cover body being operatively positionable during use thereof to seat on a manhole frame and cover said manhole opening, such that said first side of said manhole cover body is accessible from outside said manhole, said second side of said manhole cover body is disposed within said manhole, and said peripheral edge portion of said manhole cover body engages a manhole cover support surface on said manhole frame;
• a key-actuated latch mechanism operable to engage and lock said manhole cover body to said manhole frame, said latch mechanism comprising one or more retractable latch members on said second side of said cover plate body and a latch drive unit, said latch drive unit being operatively coupled to said latch members and accessible on said first side of said manhole cover body for engagement by a security key;
• a manhole cover tamper sensor on said second side of said manhole cover body, said manhole cover tamper sensor being responsive to a predetermined movement of said manhole security cover body;
• a transmitter operatively connected to said manhole cover tamper sensor and configured to generate a radio frequency manhole cover tamper signal when said manhole cover tamper sensor detects said predetermined movement of said manhole security cover body;
• an antenna operatively coupled to said transmitter to radiate radio frequency energy through said manhole cover body to a receiver located outside of said manhole;
• an electromechanical latch actuator operable to support keyless entry to said manhole by automatically unlatching said latch mechanism;
• and
• a wireless receiver operatively coupled to said latch actuator and configured to control said latch actuator to unlatch said latch mechanism in response to a latch mechanism wireless control signal received by said receiver unit from outside said manhole.

A manhole security cover for covering an opening to a manhole, comprising:

• a manhole cover body comprising a non-metallic RF signal transmissive material;
• said manhole cover body having a generally planar first side, a second side spaced from said first side and a peripheral edge portion;
• said manhole cover body being operatively positionable during use thereof to seat on a manhole frame and cover said manhole opening, such that said first side of said manhole cover body is accessible from outside said manhole, said second side of said manhole cover body is disposed within said manhole, and said peripheral edge portion of said manhole cover body engages a manhole cover support surface on said manhole frame;
• a key-actuated latch mechanism operable to engage and lock said manhole cover body to said manhole frame, said latch mechanism comprising one or more retractable latch members on said second side of said cover plate body and a latch drive unit, said latch drive unit being operatively coupled to said latch members and accessible on said first side of said manhole cover body for engagement by a security key;
• a manhole cover tamper sensor on said second side of said manhole cover body, said manhole cover tamper sensor being responsive to a predetermined movement of said manhole security cover body;
• a transmitter operatively connected to said manhole cover tamper sensor and configured to generate a radio frequency manhole cover tamper signal when said manhole cover tamper sensor detects said predetermined movement of said manhole security cover body;
• an antenna operatively coupled to said transmitter to radiate radio frequency energy through said manhole cover body to a receiver located outside of said manhole;
• an electromechanical latch actuator operable to support two-stage entry to said manhole by automatically unlocking said latch mechanism to allow mechanical key actuation;
• and
• a wireless receiver operatively coupled to said latch actuator and configured to control said latch actuator to unlock said latch mechanism in response to a latch mechanism wireless control signal received by said receiver unit from outside said manhole.

A manhole security cover for covering an opening to a manhole, comprising:

• a manhole cover body comprising a non-metallic RF signal transmissive material;
• said manhole cover body having a generally planar first side, a second side spaced from said first side and a peripheral edge portion;
• said manhole cover body being operatively positionable during use thereof to seat on a manhole frame and cover said manhole opening, such that said first side of said manhole cover body is accessible from outside said manhole, said second side of said manhole cover body is disposed within said manhole, and said peripheral edge portion of said manhole cover body engages a manhole cover support surface on said manhole frame;
• a manhole cover tamper sensor on said second side of said manhole cover body, said manhole cover tamper sensor being responsive to a predetermined movement of said manhole security cover body;
• a transmitter housing on said second side of said manhole cover body, said transmitter housing containing a transmitter and an antenna;
• said transmitter being operatively connected to said manhole cover tamper sensor and configured to generate a radio frequency manhole cover tamper signal when said manhole cover tamper sensor detects said predetermined movement of said manhole security cover body;
• said antenna being operatively coupled to said transmitter to radiate radio frequency energy through said manhole cover body to a receiver located outside of said manhole;
• and
• a thin film sensor on said second side of said manhole cover body, said thin film sensor being responsive to manhole cover integrity disruption due to an attempt to penetrate said manhole cover body, said thin film sensor being operatively connected to said transmitter (or to a separate transmitter) and said transmitter (or said separate transmitter) being configured to generate a manhole cover integrity violation signal when said thin film sensor senses said integrity disruption.