Page 80 - LIFT VISION 39 IÇ SAYFA

SAFETY DEVICES

ELEVATOR SAFETY

There are about 20 million elevators in ser-
vice around the world, with more than 1
million new elevators being commissioned
every year. Thanks to safety standards for
elevators, these elevators transport billions of
people every day. Wherever there is an ele-
vator that affects the lives of so many people,
ensuring the safety of passengers should be
the most important issue for those involved
in the elevator business.

‘Elevator safety’ means that the elevator can
safely transport a number of people or loads
equivalent to the nominal load for which the
elevator is designed from one floor to another
at the specified speed. In order for elevators
to be safe, 6 Safety Components are defined by Muharrem Bilge ÇAKIRER
according to the 2014/33/EU Elevator Re- R&D Engineer - Merih Asansör A.Ş. / TSE Elevator Technical Committee Member
gulation. Two of these six vital safety com-
ponents, the Speed Regulator and the Brake
System, work in cooperation to ensure safety. red cabin or the button panel model during in accordance with the geometry of the roller
the contract phase to be signed between ca- and its inclined seat. The rail is compressed
Safety devices in terms of braking mode in bin manufacturers and contractors. However, between these two parts. In the meantime, the
order of historical development: the least dangerous parts of elevators are the springs with low stiffness stretch. The resul-
a( sudden braking, parts that are visible to the end user; the invi- ting normal force turns into frictional force
b( sudden braking & bumper effect, sible parts such as safety devices are the parts and starts to consume the kinetic energy of
c( sliding safety device, where the risks are the highest. the car. This friction continues until the car
can be analyzed in three parts. stops.
Parachute Systems, which find a place in EN
According to EN 81-20/-50 standards; safety 81-20/-50 standards under the name of ‘sa- The task of the Speed Regulator, one of the
devices with sudden braking are used in ca- fety device’, are defined as; “A mechanical safety devices of the elevator, is to ensure that
ses where the declared speed of the elevator device used to stop the downward movement the safety rope is in sufficient tension and to
does not exceed 0,63 m/s. Since the stopping of the cabin, counterweight or counterbalan- disable the elevator when this rope loosens.
distance of the safety device, which performs ce weight by activating in case of excessive A minimum tension force of 300 Nm must be
the full clutch action on the guide rails almost acceleration or breakage of the suspension transmitted from the speed governor )safety(
instantaneously, is small, the car and guide device and to keep them immobilized on the rope to the brake lever in order to activate
rails are overstressed. If the rated speed exce- guide rails.” the brake device. In case the suspension ro-
eds 0.63 m/s, a sliding safety device must be pes carrying the elevator break or the descent
used. ‘Buffer-acting brakes’ have been pha- The simplest way to stop a moving object speed increases excessively, the movement
sed out. In this article, we will mainly exami- within a certain period of time by absorbing of the regulator rope, which is connected to
ne sliding type braking systems. its kinetic energy is to convert its kinetic the cabin on one side and moves conjugately
energy into heat through friction. In gene- with the cabin, stops when the claw called
Parachute systems, which are extremely ral, when the brake mechanism is activated, ‘beak’ in the sector locks the regulator pul-
important for the safety of passengers in one half of the brake attached to the cab is ley. With the regulator rope immobilized, the
high-speed elevators, are not even as much brought into contact with the rail by springs, brake lever connected to the regulator rope in
on the agenda as the coating of the prefer- while the other half is pressed against the rail the cab, which has been in motion until that

80 LIFTVISION
4th QUARTER 2023