ELECTRONIC SAFETY DEVICE AND A CONVEYOR SYSTEM

• US 20160214800A1
• Filed: 12/07/2015
• Published: 07/28/2016
• Est. Priority Date: 01/28/2015
• Status: Active Grant

• Current Assignee: Kone Corporation
• Original Assignee: Kone Corporation
• Inventors: RAASSINA, Pasi
• Granted Patent: US 9,731,904 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B65G 43/00 Control devices, e.g. for safety, warning or fault-correcting
• CPC Class Codes: B66B 25/006 Monitoring for maintenance or repair for security reasons B66B29/005
• CPC Class Codes: B66B 5/0031 for safety reasons
• CPC Class Codes: G05B 9/02 electric

Abstract

The invention relates to an electronic safety device and a conveyor system comprising the same. The electronic safety device has a safety input for receiving a safety signal, the electronic safety device being configured to terminate its operation responsive to absence of the safety signal in the safety input. The electronic safety device comprises an operation-preventing circuit configured to detect an operational anomaly in the safety input, the operation-preventing circuit comprising a switch adapted to short the safety input when the operational anomaly is present in the safety input.

Claims

1. An electronic safety device having a safety input for receiving a safety signal and a safety logic configured to block operation of the electronic safety device responsive to absence of the safety signal in the safety input, wherein the electronic safety device comprises an operation-preventing circuit configured to detect an operational anomaly in the safety input, the operation-preventing circuit comprising a switch adapted to short the safety input when an operational anomaly is present in the safety input.

2. The electronic safety device according to claim 1, wherein the operational anomaly is an unallowed voltage in the safety input.

3. The electronic safety device according to claim 2, wherein the operation-preventing circuit is configured to detect an unallowed voltage in the safety input by momentarily shorting the safety input.

4. The electronic safety device according to claim 3, wherein the operation-preventing circuit is configured to detect an unallowed voltage in the safety input by momentarily shorting the safety input in power-up situation of the electronic safety device.

5. The electronic safety device according to claim 1, wherein the switch is configured to short the safety input as long as the operational anomaly is present in the safety input.

6. The electronic safety device according to claim 1, wherein the switch is configured to short the safety input responsive to an overvoltage in the safety input.

7. The electronic safety device according to claim 1, wherein the operation-preventing circuit comprises a power supply having its output coupled to the control pole of the switch.

8. The electronic safety device according to claim 1, wherein the switch is a thyristor.

9. The electronic safety device according to claim 1, wherein the electronic safety device is configured to permit its operation responsive to presence of the safety signal in the safety input.

10. The electronic safety device according to claim 1, wherein the electronic safety device is a control device of an electromagnetic brake.

11. The electronic safety device according to claim 1, wherein the electronic safety device is a conveyor drive unit.

12. A conveyor system comprising a safety system configured to output a safety signal, wherein the conveyor system comprises the electronic safety device according to claim 1, the safety input of the electronic safety device being coupled to the safety signal.