In order to ensure the safety factor of the lifting platform, the safety device of the lifting platform is provided with many:
1. Fall arrester
The anti-falling safety device is an important component on the lifting platform, and it relies on it to eliminate the occurrence of the fall accident of the cage and ensure the safety of the occupant. Therefore, the factory safety test of the anti-falling safety device is very strict. The torque is measured by the legal inspection unit before the factory, the measurement at the critical speed, the measurement of the spring compression amount, and each test report is attached to the elevator. The drop test under rated load is carried out, and the lifting platform in use on the construction site must be subjected to a drop test every three months. For the two-year lifting platform anti-falling safety device (the date of delivery on the anti-falling safety device), it must also be sent to the statutory inspection unit for testing and testing, and once every year. Few people have been sent for inspection so far. Some construction sites do not even test the fall test every three months. They all think that their anti-fall safety device has no problem, but they regret it once they have an accident. Why not test and check regularly according to the system? It is better to use the unit blindly and think it is not bad. In fact, the safety of the anti-falling safety device can only be judged by the test and the inspection. It is impossible to determine whether it is good or bad in daily operation. For those anti-fall safety devices that are overdue service, it is recommended to send the inspection early and periodically. The test is good, and only when you have the heart, can you prevent a serious accident.
2. Safety switch
The safety switches of the elevators are designed according to safety requirements, such as fence door limit, cage door limit, top door limit, limit position switch, upper and lower limit switch, counterweight anti-break rope protection switch, etc. In some construction sites, in order to save trouble, some limit switches are manually canceled and short-circuited or damaged, and it is not repaired in time. This is equivalent to canceling these safety lines and planting accidents. For example: the cage should be loaded with long things, and the cage should not be placed outside the cage, and the door limit or the top door limit should be manually removed. If the above safety facilities are imperfect or incomplete, the manned cargo will still be loaded. This kind of illegal operation is a joke of taking people's lives. In order to avoid the occurrence of accidents, it is hoped that the unit leaders will strengthen management and strictly require the maintenance and operation personnel of the lifting platform to regularly check the safety and reliability of various safety switches to prevent accidents.
3. Wear replacement of gears and racks
Construction on the construction site, the working environment is bad, cement, mortar, dust can not be cleaned, the gears and racks are ground together, the teeth are still sharpened and still in use, should be paid attention to. It is well known that the tooth profile should be like a cantilever beam, and when worn to a certain size, the gear (or rack) must be replaced. To what extent is it worn out to stop using the replacement? It can be measured with a 25-50mm common normal micrometer. When the common normal length of the gear is worn from 37.1mm to less than 35.1mm (2 teeth), the new gear must be replaced. When the rack is worn, it is measured by the tooth thickness caliper. When the tooth height is from 8.56mm to less than 10.6mm when the string height is 8mm, the rack must be replaced. However, many "old teeth" gears and racks are lifted on the construction site. The platform is still in service for extended periods of time and new accessories must be replaced for safety reasons.
4. Duty cycle
The elevators on the construction site are frequently operated, and the utilization rate is high, but the problem of the intermittent working system of the motor has to be considered, which is often referred to as the problem of the duty ratio (sometimes called the load continuation rate). It is defined as FC = duty cycle time / load Time × 100%, where the duty cycle time is load time and down time. Some of the lifting platforms on the construction site are rented by the leasing company. They always want to make full use of them. The temporary load rate of the motor (FC=40% or 25%) is completely ignored. How can the motor not heat up? Some even use a burnt smell and still use it, which is very abnormal operation. If the elevator drive system is poorly lubricated or the running resistance is too large, overloaded, or frequently started, it is illegal operation.
The last line of defense for the lifting platform of the bumper on the lift, first, it must be set. Second, it must have a certain strength, can withstand the impact of the rated load of the lift, and play a buffering role.