Elevator safety circuit with safety relay delay
AssigneeInventio AG
InventorJuan Carlos Abad
Life of this patent
Estimating the term…
Abstract
An elevator safety circuit can be used to decelerate an elevator car during an emergency stop in a controlled manner. The safety circuit includes a series chain of safety contacts having an input connected to a power source and a first safety relay deriving electrical power from an output of the series chain of safety contacts. A delay circuit is arranged between the output of the series chain of safety contacts and the first safety relay. Hence, if any of the safety contacts open to initiate an emergency stop, a process controlled by the operation of the first safety relay is delayed.
Claims16
An elevator safety circuit comprising:
- a series chain of safety contacts comprising a power source input;
- a first safety relay configured to be energized by electrical power from an output of the series chain of safety contacts;
- a delay circuit arranged between the output of the series chain of safety contacts and the first safety relay for continued energizing of the first safety relay for a predetermined time interval after opening of any one of the safety contacts;
- and
- a watchdog timer arranged to selectively bypass and de-energize the first safety relay.
An elevator safety circuit comprising:
- a series chain of safety contacts comprising a power source input;
- a first safety relay configured to be energized by electrical power from an output of the series chain of safety contacts;
- a delay circuit arranged between the output of the series chain of safety contacts and the first safety relay for continued energizing of the first safety relay for a predetermined time interval after opening of any one of the safety contacts;
- and
- a second safety relay arranged in parallel with the delay circuit and the first safety relay and configured to be energized by the electrical power from the output of the series chain of safety contacts.
A method for controlling an elevator, the method comprising:
- detecting an opening of a safety contact;
- operating a first safety relay a predetermined time interval after the opening of the safety contact;
- monitoring a drive of the elevator;
- and
- operating the first safety relay when the drive experiences a software problem, a hardware problem or if the power supply to the drive is outside of a permitted tolerance.
An elevator installation, comprising:
- an elevator car disposed in a shaft;
- and
- an elevator safety circuit, the elevator safety circuit comprising,
- a series chain of safety contacts comprising a power source input,
- a first safety relay configured to be energized by electrical power from an output of the series chain of safety contacts,
- a delay circuit arranged between the output of the series chain of safety contacts and the first safety relay for continued energizing of the first safety relay for a predetermined time interval after opening of any one of the safety contacts, and
- a watchdog timer arranged to selectively bypass and de-energize the first safety relay.
An elevator installation, comprising:
- an elevator car disposed in a shaft;
- and
- an elevator safety circuit, the elevator safety circuit comprising,
- a series chain of safety contacts comprising a power source input,
- a first safety relay configured to be energized by electrical power from an output of the series chain of safety contacts,
- a delay circuit arranged between the output of the series chain of safety contacts and the first safety relay for continued energizing of the first safety relay for a predetermined time interval after opening of any one of the safety contacts, and
- a second safety relay arranged in parallel with the delay circuit and the first safety relay and configured to be energized by the electrical power from the output of the series chain of safety contacts.
Dependencies are inferred from the claim text.