Elevator systems
An elevator system is provided which includes a plurality of hoistway doors, a corresponding plurality of sets of non-contact switches, each set arranged to detect when a respective hoistway door is open, and a monitoring device. Each set of non-contact switches comprises a first non-contact switch arranged to open when the respective hoistway door is open and a second non-contact switch arranged to open when the respective hoistway door is open. The first non-contact switches of the plurality of sets are connected in series to form a first electrical path and the second non-contact switches of the plurality of sets are connected in series to form a second electrical path. The monitoring device is arranged to measure an electrical property of the first electrical path and an electrical property of the second electrical path to detect when a hoistway door is open.
1 . An elevator system ( 2 ) comprising:
a plurality of hoistway doors ( 10 a , 10 b , 10 c );
a corresponding plurality of sets of non-contact switches ( 12 a , 12 b , 12 c ), each set arranged to detect when a respective hoistway door ( 10 a , 10 b , 10 c ) is open; and
a monitoring device ( 26 );
wherein:
each set of non-contact switches ( 12 a , 12 b , 12 c ) comprises a first non-contact switch ( 14 a , 14 b , 14 c ) arranged to open when the respective hoistway door ( 10 a , 10 b , 10 c ) is open and a second non-contact switch ( 16 a , 16 b , 16 c ) arranged to open when the respective hoistway door ( 10 a , 10 b , 10 c ) is open;
the first non-contact switches ( 14 a , 14 b , 14 c ) of the plurality of sets ( 12 a , 12 b , 12 c ) are connected in series to form a first electrical path ( 22 ) and the second non-contact switches ( 16 a , 16 b , 16 c ) of the plurality of sets ( 12 a , 12 b , 12 c ) are connected in series to form a second electrical path ( 24 ); and
the monitoring device ( 26 ) is arranged to measure an electrical property of the first electrical path ( 22 ) and an electrical property of the second electrical path ( 24 ) to detect when a hoistway door ( 10 a , 10 b , 10 c ) is open;
wherein each set of non-contact switches further comprises a first bypass impedance ( 18 a , 18 b , 18 c ) connected in parallel with the first non-contact switch ( 14 a , 14 b , 14 c ) and/or a second bypass impedance ( 20 a , 20 b , 20 c ) connected in parallel with the second non-contact switch ( 16 a , 16 b , 16 c ).
2 . The elevator system ( 2 ) as claimed in claim 1 , wherein the monitoring device ( 26 ) is arranged to measure a resistance of the first and/or second electrical path ( 22 , 24 ).
3 . The elevator system ( 2 ) as claimed in claim 1 , wherein the first and/or second bypass impedances ( 18 a , 18 b , 18 c , 20 a , 20 b , 20 c ) are different.
4 . The elevator system ( 2 ) as claimed in claim 3 , wherein each first bypass impedance ( 18 a , 18 b , 18 c ) and/or each second bypass impedance ( 20 a , 20 b , 20 c ) is different, such that each unique combination of open and closed hoistway doors ( 10 a , 10 b , 10 c ) corresponds to a unique impedance of the first and/or second electrical paths ( 22 , 24 ).
5 . The elevator system ( 2 ) as claimed in claim 1 , wherein the at least one first and/or second bypass impedance ( 18 a , 18 b , 18 c , 20 a , 20 b , 20 c ) comprises a plurality of electronic components.
6 . The elevator system ( 2 ) as claimed in claim 1 , wherein the monitoring device ( 26 ) is arranged to measure a first electrical property of the first and/or second electrical path ( 22 , 24 ) when operated in a first mode, and to measure a second electrical property of the first and/or second electrical path ( 22 , 24 ) when operated in a second mode.
7 . The elevator system ( 2 ) as claimed in claim 6 , wherein the monitoring device ( 26 ) is arranged to switch from operating in the first mode to operating in the second mode upon detection of an open hoistway door.
8 . An elevator system ( 102 ) comprising:
a plurality of hoistway doors ( 10 a , 10 b , 10 c ) and
a corresponding plurality of sets of non-contact switches ( 112 a , 112 b , 112 c ), each set arranged to detect when a respective hoistway door ( 10 a , 10 b , 10 c ) is open; and
a monitoring device ( 126 );
wherein each set of non-contact switches ( 112 a , 112 b , 112 c ) comprises:
a first non-contact switch ( 114 a , 114 b , 114 c ) arranged to open when the respective hoistway door ( 10 a , 10 b , 10 c ) is open;
a first impedance ( 118 a , 118 b , 118 c ) connected in series with the first non-contact switch ( 114 a , 114 b , 114 c );
a second non-contact switch ( 116 a , 116 b , 116 c ) arranged to open when the respective hoistway door ( 10 a , 10 b , 10 c ) is open; and
a second impedance ( 120 a , 120 b , 120 c ) connected in series with the second non-contact switch ( 116 a , 116 b , 116 c );
wherein the first non-contact switch ( 114 a , 114 b , 114 c ) and the first impedance ( 118 a , 118 b , 118 c ) are connected in parallel with the second non-contact switch ( 116 a , 116 b , 116 c ) and the second impedance ( 120 a , 120 b , 120 c );
wherein the sets of non-contact switches ( 112 a , 112 b , 112 c ) are connected in series to form an electrical path ( 122 ); and
wherein the monitoring device ( 126 ) is arranged to measure an electrical property of the electrical path ( 122 ) to detect when a hoistway door ( 10 a , 10 b , 10 c ) is open.
9 . The elevator system ( 102 ) as claimed in claim 8 , wherein the monitoring device ( 126 ) is arranged to measure a resistance of the electrical paths ( 122 ).
10 . The elevator system ( 102 ) as claimed in claim 8 , wherein two or more first and/or second impedances ( 118 a , 118 b , 118 c , 120 a , 120 b , 120 c ) are different.
11 . The elevator system ( 102 ) as claimed in claim 10 , wherein each first impedance ( 118 a , 118 b , 118 c ) is different and/or each second impedance ( 120 a , 120 b , 120 c ) is different, such that each unique combination of open and closed hoistway doors corresponds to a unique impedance of the electrical path ( 122 ).
12 . The elevator system ( 102 ) as claimed in claim 8 , wherein each set of non-contact switches ( 112 a , 112 b , 112 c ) comprises a bypass impedance ( 117 a , 117 b , 117 c ) connected in parallel with the first and second non-contact switches ( 114 a , 114 b , 114 c , 116 a , 116 b , 116 c ).
13 . The elevator system ( 102 ) as claimed in claim 12 , wherein at least one bypass impedance ( 117 a , 117 b , 117 c ) comprises a plurality of electronic components.
14 . An elevator system ( 202 ) comprising:
a plurality of hoistway doors ( 10 a , 10 b , 10 c ) and
a corresponding plurality of sets of non-contact switches ( 212 a , 212 b , 212 c ), each set arranged to detect when a respective hoistway door ( 10 a , 10 b , 10 c ) is open; and
a monitoring device ( 226 );
wherein:
each set of non-contact switches ( 212 a , 212 b , 212 c ) comprises at least one non-contact switch ( 214 a , 214 b , 214 c ), and at least one further electronic component ( 218 a , 218 b , 218 c , 220 a , 220 b , 220 c ) connected in parallel with the non-contact switch ( 214 a , 214 b , 214 c ) so that each set of non-contact switches ( 212 a , 212 b , 212 c ) comprises a unique AC electrical property;
the sets of non-contact switches ( 212 a , 212 b , 212 c ) are connected in series to form an electrical path ( 222 ); and
the monitoring device ( 226 ) is arranged to measure an AC electrical property of the electrical path ( 222 ) to detect and identify an open hoistway door ( 10 a , 10 b , 10 c ).