Modern Design of Machinery Guarding and Presence-Sensing Devices

This presentation discusses the importance of machinery guarding and presence-sensing devices in preventing occupational injuries. It covers common hazards, types of machine guarding, and types of presence-sensing devices. The presentation emphasizes the need for proper installation and understanding of these safety devices to reduce the risk of accidents. References are provided for further reading.

MODERN DESIGN OF
MACHINERY GUARDING AND
PRESENCE-SENSING DEVICES
Name of the Student
Name of the University

Introduction
■ Work accidents or occupational
accidents refer to discrete
occurrences in the course of work that
lead to mental or physical
occupational injuries
■ Occupational injuries encompass
bodily damage that results from
working.
■ Some of the most common
occupational injuries involve the
hands, spine, eyes, lugs, skin and the
bones.

Occupational injuries
■ Occupational injuries can result due to
exposure to a range of workplace
hazards
■ The International Labour Organisation
states that more than an estimated 337
million accidents occur on the job every
year, leading to occupational diseases
(Ilo.org 2018).
■ This accounts for an approximate 2.3
million deaths among people.

Singapore statistics
■ The rolling injury rate over a period of 12 months was around
1.3/100,000 employed individuals (Wsh-institute.sg 2018)
■ 268 workers were found to sustain major workplace injuries,
■ The rolling injury rate for them was 16.8/100,000 employed people.
■ Approximately 1.5 incidents occurred for every million man-hour that
had been worked (accident frequency rate)

Machine guards
■ Each piece of machinery are found to be
in possession of a set of unique
mechanical and non-mechanical
hazards.
■ Machines are responsible for causing
different types of injuries among their
operators, ranging from minor burns,
abrasions and cuts to severe ones such
as, lacerations, fractures, amputation or
even crushing.

Common hazards
A wide variety of actions and motions have the capability of presenting
hazards to the workers who are operating in or around the machinery.
Three of the most common types of hazards are given below:
■ Hazardous motions
■ Shear points or pinch points
■ Points of operations (Vallmuur et al. 2016)

Machine guarding
■ Machine guards refer to protective
devices that have the power of
covering pieces of a machine that are
in motion, and might pose danger to all
workers.
■ These are a major form of safety
feature that are installed on or around
machines, which are identified to be
responsible for occupational injuries
among workers or operators (Parker et
al. 2016)

Mechanism of machine guarding
■ Machine guards are termed as rigid forms of physical barrier that
are designed in a way that allows the enclosure or covering of
machine parts, commonly designated unsafe for human contact.
■ Coupled with adjustable or interlocked safety operations these
guards also result in an increased protection level for all kinds of
point-of-operation guarding (Wshc.sg 2018).

Types of machine guarding (1)
■ Fixed guards are permanently attached to the
machinery by screws that prevent workers
from accessing any danger zone from all
directions.
■ These guards cannot be removed from the
machines without proper tools
■ Adjustable guards can be moved or
reconfigured, based on the work dimensions
that is being performed (Chinniah 2015)
■ These guards help in handling materials of
different sizes and also protect the operators
present in the danger zone

Types of machine guarding (2)
■ Interlocking guards are another type of
machinery guarding that disengage or
shut down the power of the machine,
when they are opened or taken out of
their normal position.
■ The guards stop motion of the
dangerous operations and lead to
manual restart of the machinery under
such conditions (Yamin et al. 2014).

Presence-sensing devices
■ Presence-sensing devices are another
safety device that are principally used for
pressing brake safety.
■ They are at times preferred over the
machinery guarding due to their role in
increasing the productivity of the
operations by increasing the access for
routine maintenance of the machinery
(Wshc.sg 2018).

Types of PSDs (1)
■ Safety light curtains that contain two
retroreflective muting sensors and a
muting box allow the workplace access,
without halting any other work process.
■ Safety light curtains have corner mirrors
and provide guarding for the perimeter,
for the entire work zone (Irfani 2015).
■ Laser scanners are also configured in a
way that assist in the easy detection of
irregular areas present in the workplace.

Types of PSDs (2)
■ Safety mats are installed at the entry
are of the machinery processes and
help in detection of the presence of
workers and other employees inside
the cell.
■ Gate interlock safety switches are
also one form of presence-sensing
safety device that prevent hazardous
motion in the area, under situations
when the personnel try entering
through the gates

Conclusion
■ Lack of sound understanding of the machinery guarding devices or
improper installation of these safety devices are some of the risk
factors that contribute to machine related workplace accidents.
■ Proper installation will be able to reduce this risk, thereby lowering
the rates of occupational accidents

References
Chinniah, Y., 2015. Analysis and prevention of serious and fatal accidents related to moving parts of machinery. Safety science, 75,
pp.163-173.
Ilo.org., 2018. Safety and health at work. [online] Available at: http://www.ilo.org/global/topics/safety-and-health-at-work/lang--en/
index.htm [Accessed 12 Jul. 2018].
Irfani, T.H., 2015. Occupational injuries and illnesses in rubber factory: Profile, Potential Hazards and possible prevention. Public
Health of Indonesia, 1(2), pp.32-37.
Mekkodathil, A., El-Menyar, A. and Al-Thani, H., 2016. Occupational injuries in workers from different ethnicities. International
journal of critical illness and injury science, 6(1), p.25.
Mrugalska, B. and Arezes, P.M., 2013. Safety requirements for machinery in practice. In Occupational safety and hygiene(Vol. 97,
No. 101, pp. 97-101). ROUTLEDGE in association with GSE Research.
Parker, D.L., Yamin, S.C., Brosseau, L.M., Xi, M., Gordon, R., Most, I.G. and Stanley, R., 2015. National machine guarding program:
Part 1. Machine safeguarding practices in small metal fabrication businesses. American journal of industrial medicine, 58(11),
pp.1174-1183.
Parker, D.L., Yamin, S.C., Xi, M., Brosseau, L.M., Gordon, R., Most, I.G. and Stanley, R., 2016. Findings from the National Machine
Guarding Program–A Small Business Intervention: Machine Safety. Journal of occupational and environmental medicine, 58(9),
p.885.
Vallmuur, K., Marucci-Wellman, H.R., Taylor, J.A., Lehto, M., Corns, H.L. and Smith, G.S., 2016. Harnessing information from injury
narratives in the ‘big data’era: understanding and applying machine learning for injury surveillance. Injury prevention, 22(Suppl 1),
pp.i34-i42.
Westerman, W.C., Hotelling, S.P., Haggerty, M., Ording, B., Parivar, N. and Kerr, D.R., Apple Inc, 2016. Gesturing with a multipoint
sensing device. U.S. Patent 9,292,111.
Wshc.sg., 2018. Workplace Safety and Health Guidelines. [online] Available at:
https://www.wshc.sg/files/wshc/upload/infostop/attachments/2015/IS201503240000000306/WSH_Guidelines_on_Safe_Use_of_Mach
inery.pdf
. [Accessed 12 Jul. 2018].
Wsh-institute.sg., 2018. [online] Available at: https://www.wsh-institute.sg/files/wshi/upload/cms/file/1H17%20Report%20-
%20Infographics%20(24%20Aug).pdf [Accessed 12 Jul. 2018].

Thank you!