Cover:Serum Institute Burj Khalifa - Elevator World India

Engineering
Assumption on New Design
of Two Safety Components
by Huang Dongling and Xing Jian
Buffer Vertical Baffle
EN 115 5.2.4 prescribes, “Where building obstacles can
cause injuries, appropriate preventive measures shall be
taken; see 7.3.1.” In particular, at floor intersections and on
criss-cross escalators or passenger conveyors, a vertical
obstruction of not less than .3 m in height, not presenting
any sharp cutting edges, shall be placed above the
balustrade decking (e.g., as an imperforate triangle). It is
not necessary to comply with these requirements when
the distance between the centerline of the handrail and
any obstacle is equal to or greater than .5 m.
According to the above prescription and the analysis of
previous escalator accidents, the vertical baffle has two
functions: 1) to prevent the passengers from being
trapped between the escalator and the obstacle and 2) to
change the impact direction toward the passengers.
However, the escalator standard doesn’t provide whether
the vertical baffle and the building should be connected
permanently or temporarily, or, if the connection is permanent,
how much connection strength there should be.
The impact of the permanent baffle against the human
Figure 1: 1=bolt, 2=spacer, 3=baffle, 4=sheet metal (a)=enlarged figure
through direction A, (b)=front view, (c)=left view, (d)=view when the baffle is
impacted and (e)=enlarged figure through B.
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ELEVATOR WORLD India • 4th Quarter 2010 •
body is great, and the baffle itself is easily damaged and
may cause injuries, while the removable baffle can only
remind the passengers of drawing back timely (but cannot
prevent, in essence, the passengers from being
trapped between the escalator and the obstacle, nor reduce
the impact against the body). In order to solve such
problems, we have designed a new baffle ((a) in Figure 1).
The baffle is made of organic glass, light and aesthetic.
The angle α is equal to the sliding angle of the escalator.
The baffle curls outward to enlarge the distance between the
handrail and buffer vertical baffle, while reducing the impact
of the baffle against the human body. The sheet-metal
material is elastic sheet steel with suitable stiffness.
This kind of baffle is improved from the traditional baffle.
When a crash happens, the sheet metal will produce
an elastic deformation ((b) in Figure 1) toward the running
direction of the escalator and thereby absorb part of the
kinetic energy from the crash. In this way, it buffers the
impact against the objects (human bodies) and therefore
reduces the impact strength and the potential injury
toward human bodies and extends the service life of the
Continued
Figure 2: 1=car (or counterweight) strike plate, 2=knock rod, 3=restoring
spring, 4=upper bracket, 5=arresting pin, 6=piston, 7=lower bracket,
8=switch and 9=base