Monitoring system for door stations

Claim 2

A monitoring system in which a central console is wired to remote door stations, each station being provided with a first switch which is closed when the door is closed and is opened when the door is opened legally, said console comprising: A. a bank of light indicators equal in number to the number of first switches, B. An electromechanical relay for operating each indicator, said relay having contact sections, C. a light re-set switch connected to said indicator relays to supply energizing current thereto from a console supply to actuate same when the switch is momentarily closed, one of said contact sections of each relay then acting to supply current to the light indicator associated therewith to produce a steady illumination, D. means connecting the first switch at each station to the corresponding relay through another contact section thereof to supply a holding current thereto to maintain said relay energized and thereby to operate the associated light indicator to provide steady illumination as long as said first switch is closed, said relays being de-energized when said first switch is open, E. a flasher unit for said light indicators, and F. means to connect said flasher unit to that indicator whose relay is de-energized, to provide periodic illumination indicating that the first switch is open whereby in the condition when the door at any station is closed the related light indicator on the console provides steady illumination to indicate this condition, and in another condition when the dor is legally opened the same light indicator is periodically illuminated to indicate that condition.

Claim 3

A system as set forth in claim 6, wherein said relays are electromechanical devices which require an actuating voltage whose magnitude is greater than the voltage required to hold it in the energized state.

Claim 4

A system as set forth in claim 6, wherein said relays are solid state devices.

Claim 5

A system as set forth in claim 6, wherein said alarm is a buzzer.

Claim 6

A system as set forth in claim 6, wherein said flasher unit includes a solid state relaxation oscillator whose output is applied to a relay to produce a periodic switching action.

Claim 7

A monitoring system in which a central console is wired to remote door stations, each station being provided with a first switch which is closed when the door is closed and is opened when the door is legally opened, and a second switch which is oPened only when the door is illegally opened, said console comprising: A. a bank of light indicators equal in number to the number of first switches, B. a relay for operating each indicator, said relay having contact sections, C. a light re-set switch connected to said indicator relays to supply energizing current thereto from a console supply to actuate same when the switch is momentarily closed, one of said contact sections of each relay then acting to supply current to the light indicator associated therewith to produce a steady illumination, D. means connecting the first switch at each station to the corresponding relay through another contact section thereof to supply a holding current thereto to maintain said relay energized and thereby to operate the associated light indicator to provide steady illumination indicating a closed door condition as long as said first switch is closed, said relay being de-energized when said first switch is open, E. a flasher unit for said light indicators, F. means to connect said flasher unit to that indicator whose relay is de-energized, to provide periodic illumination indicating that the first switch is open as a result of a legal opening of the door, G. an alarm device, H. an auxiliary relay for operating said device, said auxiliary relay having contact sections, I. an alarm re-set switch connected to said auxiliary relay contact sections and acting to supply current to said alarm device only when the auxiliary relay is de-energized thereby to sound the alarm, and J. means connecting the second switches of all door stations in series with another contact section of said auxiliary relay in a holding circuit to maintain said auxiliary relay energized after it is momentarily actuated, whereby when any of said second switches opens as a result of an illegal opening of the door, said alarm is sounded.

Claim 8

A monitoring system in which a central console is wired to remote door stations, each station being provided with a first switch which is closed when the door is closed and is opened when the door is legally opened, and a second switch which is oPened only when the door is illegally opened, said console comprising: A. a bank of light indicators equal in number to the number of first switches, B. a relay for operating each indicator, said relay having contact sections, C. a light re-set switch connected to said indicator relays to supply energizing current thereto from a console supply to actuate same when the switch is momentarily closed, one of said contact sections of each relay then acting to supply current to the light indicator associated therewith to produce a steady illumination, D. means connecting the first switch at each station to the corresponding relay through another contact section thereof to supply a holding current thereto to maintain said relay energized and thereby to operate the associated light indicator to provide steady illumination indicating a closed door condition as long as said first switch is closed, said relay being de-energized when said first switch is open, E. a flasher unit for said light indicators, F. means to connect said flasher unit to that indicator whose relay is de-energized, to provide periodic illumination indicating that the first switch is open as a result of a legal opening of the door, G. an alarm device, H. an auxiliary relay for operating said device, said auxiliary relay having contact sections, I. an alarm re-set switch connected to said auxiliary relay contact sections and acting to supply current to said alarm device only when the auxiliary relay is de-energized thereby to sound the alarm, and J. means connecting the second switches of all door stations in series with another contact section of said auxiliary relay in a holding circuit to maintain said auxiliary relay energized after it is momentarily actuated, whereby when any of said second switches opens as a result of an illegal opening of the door, said alarm is sounded.

Claim 9

A monitoring system in which a control console is wired to remote door stations, each station being provided with a first switch which is closed when the door is closed and is opened when the door is opened either legally or illegally, and a second switch which is closed when the door is closed and is opened only when the door is opened illegally, said console comprising: A. a bank of indicators equal in number to the number of stations, B. an alarm, C. means connecting said first switches at each station to the corresponding indicators in said bank thereof to cause each indicator to represent either a first condition in which the door at the associated station is closed or a second condition in which the door is legally or illegally opened, and D. means connecting said second switches to said alarm to activate said alarm when any one of said second switches is opened, thereby affording notice of a third condition in which a door at any station is illegally opened.

Claim 10

A monitoring system in which a control console is wired to remote door stations, each station being provided with a first switch which is closed when the door is closed and is opened when the door is opened either legally or illegally, and a second switch which is closed when the door is closed and is opened only when the door is opened illegally, said console comprising: A. a bank of indicators equal in number to the number of stations, B. an alarm, C. means connecting said first switches at each station to the corresponding indicators in said bank thereof to cause each indicator to represent either a first condition in which the door at the associated station is closed or a second condition in which the door is legally or illegally opened, and D. means connecting said second switches to said alarm to activate said alarm when any one of said second switches is opened, thereby affording notice of a third condition in which a door at any station is illegally opened.