Elevator having a limit switch for controlling power to the drive system as an elevator car approaches a shallow pit or a low overhead

• US 8,162,108 B2
• Filed: 06/30/2006
• Issued: 04/24/2012
• Est. Priority Date: 06/30/2006
• Status: Expired due to Fees

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Sirigu, Gérard, Rebillard, Pascal, Dukacz, Olivier, Goulet, Dominique, Simonot, Alain, Cloux, Jean-Noel, Pillin, David, Picard, Florence, Beauchaud, Frédéric, Coquerelle, Thomas, Beeuwsaert, Michel, Fonteneau, Nicolas, Herkel, Peter, Tegtmeier, Dirk, Monzon, Andres, Del Rio, Fernando
• Primary Examiner(s): SALATA, ANTHONY J
• Application Number:
  US12/305,697
• Publication Number:
  US 20100155184A1
• Time in Patent Office: 2,125 Days
• Field of Search: 187/277, 187/286, 187/287, 187/293, 187/305, 187391-394, 187/288, 187/289, 187/301, 187/314, 187/316
• US Class Current: 187/289
• CPC Class Codes: B66B 13/16 Door or gate locking devices controlled or primarily controlled by condition of cage, e.g. movement or position
• CPC Class Codes: B66B 13/22 Operation of door or gate contacts
• CPC Class Codes: B66B 5/0068 by activating the safety brakes when the elevator car exceeds a certain upper or lower position in the elevator shaft
• CPC Class Codes: B66B 5/0081 by preventing falling by means of safety fences or handrails, being operable or not, mounted on top of the elevator car
• CPC Class Codes: B66B 5/0087 Devices facilitating maintenance, repair or inspection tasks devices incorporated in the buffer B66B5/288; railings on top of the car B66B11/0226
• CPC Class Codes: B66B 5/18 and applying frictional retarding forces

Abstract

The elevator has a car movable vertically within a shaft between lower and upper end positions and a drive system coupled to a traction system for controlling movement of the car. A limit switch which is open when the car is in a selected distance range from one of the end positions. The limit switch forms part of a power line supplying power to the drive system for controlling movement of the car in a direction towards that end position in an inspection operation. Thus movement of the car is prevented only in that direction when the car is in the selected distance range in an inspection operation.

Claims

1. An elevator comprising:

a car movable vertically within an elevator shaft between lower and upper end positions;

a drive system coupled to a traction system for controlling movement of the car; and

at least one limit switch which is open when the car is in a selected distance range from one of the end positions, the limit switch forming part of a power line supplying power to the drive system for controlling movement of the car in a direction towards said one of the end positions in an inspection operation such that movement of the car is prevented only in said direction when the car is in said distance range in an inspection operation;

a first control member having an activated state for selecting a first direction towards said one of the end positions for movement of the car in an inspection operation, and a deactivated state;

a first switch coupled to the first control member to be closed in the activated state of the first control member and open in the deactivated state, the first switch being connected in series with said limit switch in a first power line supplying power to the drive system for controlling movement of the car in the first direction in an inspection operation;

a second switch coupled to the first control member to be open in the activated state of the first control member and closed in the deactivated state of the first control member, the second switch forming part of a second power line supplying power to the drive system for controlling movement of the car in a second direction, opposite said first direction, in an inspection operation;

a second control member having an activated state for selecting said second direction for movement of the car in an inspection operation and a deactivated state;

a third switch coupled to the second control member to be closed in the activated state of the second control member and open in the deactivated state, the third switch being connected in series with the second switch in the second power line;

a fourth switch coupled to the second control member to be open in the activated state of the second control member and closed in the deactivated state of the second control member, the fourth switch being connected in series with said limit switch and the first switch in the first power line; and

a common switch coupled to a common control member and forming part of an inspection power line to which said first and second power lines are connected in parallel.

2. The elevator as claimed in claim 1, comprising:

a safety brake for stopping the car when triggered; and

a retractable stopping element deployed in an inspection operation for engaging a triggering member of the safety brake when the car moving in said direction reaches a selected distance within said distance range so as to secure a safety space independently of the drive system at said one of the end positions in the inspection operation.

3. The elevator as claimed in claim 1, comprising another limit switch which is open when the car is in a second selected distance range from the other one of the end positions, the other limit switch being connected in series with said second and third switches.

4. The elevator as claimed in claim 3, comprising:

a safety brake for stopping the car when triggered; and

a retractable stopping element deployed in an inspection operation for engaging a triggering member of the safety brake when the car moving in the second direction reaches a selected distance within said second distance range so as to secure a safety space independently of the drive system at the other one of the end positions in the inspection operation.

5. An elevator comprising:

a car movable vertically within an elevator shaft between lower and upper end positions;

a drive system coupled to a traction system for controlling movement of the car; and

at least one limit switch which is open when the car is in a selected distance range from one of the end positions, the limit switch forming part of a power line supplying power to the drive system for controlling movement of the car in a direction towards said one of the end positions in an inspection operation such that movement of the car is prevented only in said direction when the car is in said distance range in an inspection operation;

a foldable handrail mounted on top of the car;

a plurality of safety switches associated with the foldable handrail, the safety switches comprising a first safety switch closed only when the handrail is folded in a fully retracted position and at least one second safety switch closed when the handrail is unfolded in a fully deployed position; and

a safety chain comprising a normal operation branch including said first safety switch for supplying power to the drive system in a normal operation of the elevator and an inspection operation branch including said at least one second safety switch for supplying power to the drive system in an inspection operation of the elevator.

6. An elevator comprising:

a car movable vertically within an elevator shaft between lower and upper end positions;

a drive system coupled to a traction system for controlling movement of the car; and

at least one limit switch which is open when the car is in a selected distance range from one of the end positions, the limit switch forming part of a power line supplying power to the drive system for controlling movement of the car in a direction towards said one of the end positions in an inspection operation such that movement of the car is prevented only in said direction when the car is in said distance range in an inspection operation;

a shaft bottom switch which is closed when the car is within a selected distance from the lower end position and open when the car is beyond the selected distance from the lower end position;

a retractable toe guard mounted at the bottom of the car;

a safety switch which is closed only when the toe guard is in a fully deployed position; and

a power line for supplying power to the drive system in a normal operation of the elevator, said power line including a parallel arrangement of the shaft bottom switch and of the safety switch.

7. An elevator comprising:

a car movable vertically within an elevator shaft between lower and upper end positions;

a drive system coupled to a traction system for controlling movement of the car; and

at least one limit switch which is open when the car is in a selected distance range from one of the end positions, the limit switch forming part of a power line supplying power to the drive system for controlling movement of the car in a direction towards said one of the end positions in an inspection operation such that movement of the car is prevented only in said direction when the car is in said distance range in an inspection operation;

a plurality of landing doors providing access to the shaft;

a plurality of door safety devices each coupled to a latch mechanism of a respective landing door, each door safety device having a door release input for releasing the latch mechanism of the respective landing door in response to a first user action performed outside the shaft, and a bi-stable switch which is opened in response to said first user action and closed in response to a second user action performed outside the shaft, the second user action being enabled only when the respective landing door is completely closed;

an inspection control interface located, inside the shaft, comprising a mode switch closed by a user to select the inspection operation of the elevator; and

a safety chain comprising a plurality of series-connected switches for supplying power to the drive system, the plurality of series-connected switches comprising at least one of the bi-stable lock switches bypassed by a branch including said mode switch.