# US 2008/0185231 A1 · Elevator system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0185231 A1 - Document ID: US20080185231A1 - Status: Published application - Kind: A1 - Application number: 12/068,556 - Filed: 2008-02-07 - Published: 2008-08-07 - Earliest claimed: 2005-08-19 - Assignees: Kone Corporation - Inventors: Jari Osterman; Seppo Suur-Askola; Jarmo Myllynen; Simo Makimattila; Jukka Korpela; Joni Kiiski - Web page: https://patentgrep.com/patent/US20080185231A1 ## CPC - B66B 5/0031: {for safety reasons} - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) ## Abstract In the invention a method is presented for ensuring operating safety in an elevator system, an elevator system, and a safety device of an elevator system. The elevator system comprises at least an elevator car, elevator ropes, an elevator motor, a traction sheave and at least two holding brakes, which holding brakes are arranged to prevent movement of the elevator car when the elevator is stopped. According to the invention the first holding brake is engaged at the end of an elevator run, and the other holding brakes are engaged with a delay. When one holding brake is engaged, the state of motion of the elevator and any slipping of the brake is monitored. If the brake is detected as slipping, a procedure for preventing a hazardous situation is performed. ## Claims ### Claim 1 Method for ensuring operating safety in an elevator system, which elevator system comprises at least one elevator car, which elevator car is supported at least partially by means of elevator ropes, elevator ropes, an elevator motor, a traction sheave for moving the elevator car via the elevator ropes, and at least two holding brakes, which holding brakes are arranged to prevent the elevator car from moving when the elevator is stopped, characterized in that the method comprises the phases: a. only one holding brake (106, 107) is engaged at the end of an elevator run and the other holding brakes are engaged with a delay b. the state of motion of the elevator and any slipping of the brake with one holding brake engaged are monitored c. if the brake is detected as slipping, a measure to prevent a hazardous situation is performed ### Claim 2 (depends on 1) Method according to claim 1, characterized in that the method comprises the phase: at least one of the holding brakes (107, 106) is engaged immediately if a change is detected in the state of motion of the elevator after one holding brake (106, 107) has closed; ### Claim 3 (depends on 1, 2) Method according to claim 1 or 2, characterized in that the method comprises the phase: the motor is prevented from starting if the brake is detected as slipping in phase b) ### Claim 4 (depends on 1) Method according to claim 1, characterized in that the method further comprises the phase: a fault notification is sent to the service center if the brake is detected as slipping in phase b) ### Claim 5 Elevator system, which comprises at least one elevator car (7), which elevator car is supported at least partially by means of elevator ropes (9), elevator ropes (9), a traction sheave (6) for moving the elevator car (7) via the elevator ropes (9), an elevator motor (5), and at least two holding brakes (106, 107) per elevator car, which holding brakes (106, 107) are arranged to prevent the elevator car (7) from moving when the elevator is stopped, characterized in that the elevator system further comprises means (2) for controlling the holding brakes of the elevator, with which means i. one of the holding brakes (106, 107) can be controlled to close immediately at the end of an elevator run, and ii. the other holding brakes (106, 107) can be controlled closed with the desired delay means (3) for monitoring slipping of the brake of the elevator means for performing a procedure intended to prevent a hazardous situation, in which the first holding brake is engaged when the brake is detected as slipping ### Claim 6 (depends on 5) Elevator system according to claim 5, characterized in that the means for performing a procedure intended to prevent a hazardous situation comprise means for preventing starting of the motor ### Claim 7 (depends on 5, 6) Elevator system according to claim 5 or 6, characterized in that the force with which the brake shoe of one holding brake is arranged to press against the braking surface is smaller than the force with which the brake shoe of at least one of the other holding brakes is arranged to press against the braking surface. ### Claim 8 (depends on 5) Elevator system according to claim 5, characterized in that the system further comprises means for transmitting fault notifications. ### Claim 9 Safety device (1 13) for improving operating safety in an elevator system, which elevator system comprises an elevator car, which elevator car is supported at least partially by means of elevator ropes, elevator ropes, a traction sheave for moving the elevator car via the elevator ropes and an elevator motor, a sensor (109) for measuring the speed of rotation of the elevator motor, a sensor (108) for monitoring the temperature of the motor and means (100) for disconnecting the electrical power supply of the motor in a situation where the motor overheats, and at least two electromagnetic holding brakes (106, 107), which holding brakes are arranged to prevent movement of the elevator car when the elevator is stopped, and means (100) for closing the holding brakes at the end of an elevator run, and which safety device can be fitted as a part of the elevator system, characterized in that the safety device comprises means (104) for delaying engagement of the second holding brake a slip status monitoring unit (102), which comprises means for monitoring the state of motion of the elevator and for detecting a slipping situation means for preventing starting of the motor if the brake is slipping when the first holding brake is engaged ### Claim 10 (depends on 9) Safety device according to claim 9, characterized in that the safety device is fitted as a part of the elevator system, and the safety device is arranged to produce a delay in the engagement of the second holding brake by means of an energy store connected to the electrical power supply of the second holding brake to monitor the state of motion of the elevator based on information transmitted from the sensor (109) measuring the speed of rotation of the motor, and to prevent starting of the motor in a slipping situation of the brake utilizing the means (100) of the elevator system for disconnecting the electrical power supply of the motor in a situation where the motor overheats ### Claim 11 (depends on 10) Safety device according to claim 10, characterized in that the safety device is arranged to detect a slipping situation based on speed reference data transmitted from the control unit (100) of the elevator and information received from the sensor (109) measuring the speed of rotation of the motor. ### Claim 12 (depends on 9, 10, 11) Safety device according to any of claims 9-11 above, characterized in that the means for delaying engagement of the second holding brake comprise a capacitor. ### Claim 13 (depends on 9) Safety device according to claim 9, characterized in that the safety device is disposed in the terminal box between the control unit of the elevator and the hoisting machine of the elevator.