Elevator safety system, elevator system and method of operating an elevator system

Patent metadata

Field	Value
Publication number	US-11623841-B2
Application number	US-201816190440-A
Country	US
Kind code	B2
Filing date	Nov 14, 2018
Priority date	Dec 1, 2017
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

An elevator safety system comprises a plurality of door safety units, each door safety unit; a communication bus connecting the plurality of door safety units; a control unit connected to the communication bus for allowing communication between the plurality of door safety units and the control unit; and at least one position sensor configured for providing information about the current position of an elevator car within a hoistway. Each door safety unit is assigned to an elevator hoistway door and configured for monitoring a condition of the assigned elevator hoistway door. The control unit is configured for polling door safety units included in a subset S1, S2) of the door safety units which are located within a predetermined distance (D1, D2) from the current position of the elevator car.

First claim

What is claimed is:

1. Elevator safety system comprising:
a plurality of door safety units ( 12 ), each door safety unit ( 12 ) assigned to an elevator hoistway door ( 10 ) and configured for monitoring a condition of the assigned elevator hoistway door ( 10 );
a communication bus ( 16 ) connecting the plurality of door safety units ( 12 );
a control unit ( 13 ) connected to the communication bus ( 16 ) for allowing communication between the plurality of door safety units ( 12 ) and the control unit ( 13 ); and
at least one position sensor ( 19 ) configured for providing information about the current position of an elevator car ( 6 ) within a hoistway ( 4 );
wherein the control unit ( 13 ) is configured
for polling door safety units ( 12 ) included in a subset (S 1 , S 2 ) of the door safety units ( 12 ) which are located within a predetermined distance (D 1 , D 2 ) from the current position of the elevator car ( 6 ); and
for polling door safety units ( 12 ) which are not included in said subset (S 1 , S 2 ) less frequently or not at all.

2. Elevator safety system according to claim 1 , wherein the control unit ( 13 ) is configured for periodically polling the door safety units ( 12 ) included in the subset (S 1 , S 2 ) of door safety units ( 12 ) with a frequency (f) of 10 Hz to 30 Hz.

3. Elevator safety system according to claim 1 , wherein the control unit ( 13 ) is configured for polling the door safety units ( 12 ) included in the subset (S 1 , S 2 ) of door safety units ( 12 ) exclusively.

4. Elevator safety system according to claim 1 , wherein the control unit ( 13 ) is configured for polling the door safety units ( 12 ) not included in the subset (S 1 , S 2 ) less frequently than the door safety units ( 12 ) included in the subset (S 1 , S 2 ) of door safety units ( 12 ).

5. Elevator safety system according to claim 4 , wherein the control unit ( 13 ) is configured for polling the door safety units ( 12 ) included in the subset (S 1 , S 2 ) of door safety units ( 12 ) with a first frequency (f 1 ), and wherein the control unit ( 13 ) is configured for polling the door safety units ( 12 ) not included in the subset (S 1 , S 2 ) with a second frequency (f 2 ) which is lower than the first frequency (f 1 ).

6. Elevator safety system according to claim 1 , wherein the control unit ( 13 ) is configured for polling door safety units ( 12 ) included in a first subset (S 1 ) located within a first predetermined distance (D 1 ) from the current position of the elevator car ( 6 ) more frequently than door safety units ( 12 ) included in a second subset (S 2 ) located between the first predetermined distance (D 1 ) and a second predetermined distance (D 2 ) larger than the first predetermined distance (D 1 ) from the current position of the elevator car ( 6 ).

7. Elevator safety system according to claim 1 wherein the predetermined distance (D 1 , D 2 ) is selected such as to include a predetermined number of landings ( 8 ) ahead of or behind the current position of the elevator car ( 6 ).

8. Elevator safety system according to claim 1 , further comprising a sensor ( 19 , 25 ) configured for determining a direction of movement of the elevator car ( 6 ); wherein the control unit ( 13 ) is configured for polling more door safety units ( 12 ) located ahead of the moving elevator car ( 6 ) than door safety units ( 12 ) located behind the moving elevator car ( 6 ).

9. Elevator safety system according to claim 1 , wherein the predetermined distance (D 1 , D 2 ) depends on the speed of the elevator car ( 6 ), wherein the elevator system ( 12 ) comprises a speed sensor ( 25 ) configured for detecting the speed of the elevator car ( 6 ).

10. Elevator safety system according to claim 1 , wherein the door safety units ( 12 ) are configured for sending an alarm signal via the communication bus ( 16 ) in case a predetermined event is detected.

11. Elevator safety system according to claim 1 , wherein the communication bus ( 16 ) is a field bus.

12. Elevator system ( 12 ) comprising:
a hoistway ( 4 ) extending between a plurality of landings ( 8 ) and having a plurality of elevator hoistway doors ( 10 );
an elevator car ( 6 ) configured for moving along the hoistway ( 4 ) between the plurality of landings ( 8 ); and
an elevator safety system according to claim 1 .

13. Elevator system ( 12 ) according to claim 12 , wherein the control unit ( 13 ) is configured for stopping any movement of the elevator car ( 6 ) in case an alarm signal is transmitted via the communication bus ( 16 ) or a polled door safety unit ( 12 ) does not respond in due time.

14. Elevator system ( 12 ) according to claim 12 , wherein the position sensor ( 19 ) comprises a car component ( 21 a ) attached to the elevator car ( 6 ) or a hoistway component ( 21 b ) located within the hoistway ( 4 ).

15. Method of operating an elevator safety system according to claim 1 , wherein the method includes polling door safety units ( 12 ) included in a subset (S 1 , S 2 ) of the door safety units ( 12 ) which are located within a predetermined distance (D 1 , D 2 ) from the current position of the elevator car ( 6 ) and polling the door safety units ( 12 ) which are not included in said subset less frequently or not at all.

16. Elevator safety system according to claim 6 , wherein the control unit ( 13 ) is configured for not polling door safety units ( 12 ) not included in any of the subsets (S 1 , S 2 ).

17. Elevator safety system according to claim 1 wherein the predetermined distance (D 1 , D 2 ) is selected such as to include a predetermined number of landings ( 8 ) ahead of and behind the current position of the elevator car ( 6 ).

18. Elevator system ( 12 ) according to claim 12 , wherein the control unit ( 13 ) is configured for stopping any movement of the elevator car ( 6 ) in case an alarm signal is transmitted via the communication bus ( 16 ) and a polled door safety unit ( 12 ) does not respond in due time.

Assignees

• Otis Elevator Co

Inventors

• Tutat Andreas
• Krambeck Helge

Classifications

• B66B5/0031 Primary

  for safety reasons · CPC title

• B66B1/3453

  Procedure or protocol for the data transmission or communication · CPC title

• B66B13/22

  Operation of door or gate contacts · CPC title

• B66B1/3492

  Position or motion detectors or driving means for the detector (B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P) · CPC title

• B66B1/06 Primary

  electric · CPC title