Abstract: An improved electrical lockout mechanism includes a first connection means to a power source, and a second connection means to the power input terminal of the machine being protected. The machine being protected includes a manually-operated ON/OFF switch. A switching element is operably coupled between the first and second connection means. The switching element is adapted to selectively complete and break an electrical circuit between the first and second connection means in response to a control signal supplied thereto. A control circuit generates a control signal that is supplied to the switching element thereby causing the switching element to complete the electrical circuit between the first and second connection means under a first set of operating conditions and causing the switching element to break the electrical circuit between the first and second connection means under a second set of operating conditions in a manner that prevents unwanted machine restarts.

Abstract: An improved electrical lockout mechanism includes a first connection means to a power source, and a second connection means to a power input terminal of the machine being protected. The machine includes a manually-operated ON/OFF switch. A switching element, which is coupled between the first and second connection means, selectively completes and breaks an electrical circuit between the first and second connection means in response to a control signal supplied thereto. A control circuit generates this control signal in a manner that prevents unwanted machine restarts. The switching element may be realized by an electromagnetic relay device, or by a thyristor-based switching device such as a triac device. The electrical lockout mechanism can be integrated with a power cord that delivers electrical power to a machine, or can be integrated into the machine itself.

Abstract: An improved electrical lockout mechanism includes a first connection means to a power source, and a second connection means to the power input terminal of the machine being protected. The machine being protected includes a manually-operated ON/OFF switch. A switching element is operably coupled between the first and second connection means. The switching element is adapted to selectively complete and break an electrical circuit between the first and second connection means in response to a control signal supplied thereto. A control circuit generates a control signal that is supplied to the switching element thereby causing the switching element to complete the electrical circuit between the first and second connection means under a first set of operating conditions and causing the switching element to break the electrical circuit between the first and second connection means under a second set of operating conditions in a manner that prevents unwanted machine restarts.

Abstract: There is disclosed an improved hold circuit arrangement for controlling the hold function in a key telephone line circuit without introducing an undesired series impedance in the longitudinal path of the telephone line during any of the line circuit's normal operating states. The improved circuit arrangement employs a combination of an opto-coupled energizing circuit for detecting and responding to the presence of d.c. current on the telephone line during the hold state and two miniature relays which operate to establish a condition of electrical isolation between the opto-coupled energizing circuit and the longitudinal path of the telephone line in all operating states except during the momentary transition from the line busy to the line hold state. In another embodiment of this invention, logic circuitry is associated with the opto-coupled energizing circuit to provide lamp control indicative of the line state.

Abstract: A multi-station telephone communication system in which there is designated a master station and several other stations. Each of the stations is capable of communicating with any of a large number of standard telephone lines and non-locking pushbuttons are utilized to select the lines connected to each station. Each station is capable of monitoring the active line on which any of the other stations is communicating. Additionally, the master station is capable of supervising the conversation in any of the other stations by an ASSIST LOOP connection, in which the master station can overhear the conversation, but communicate one way with only one of the parties in the two-way communication. Each station is provided with a turret having panels in which are mounted their respective displays for indicating the active lines which are in communication with the respective turret as well as the lines in active communication with the other stations.

Abstract: A multi-station telephone communication system in which there is designated a master station and several other stations. Each of the stations is capable of communicating with any of a large number of standard telephone lines and non-locking pushbuttons are utilized to select the lines connected to each station. Each station is capable of monitoring the active line on which any of the other stations is communicating. Additionally, the master station is capable of supervising the conversation in any of the other stations by an ASSIST LOOP connection, in which the master station can overhear the conversation, but communicate one way with only one of the parties in the two-way communication. Each station is provided with a turret having panels in which are mounted their respective displays for indicating the active lines which are in communication with the respective turret as well as the lines in active communication with the other stations.