Most of the fundamental machine safeguarding principles originated during the early 1900's with the advent of the industrial revolution. During the past century, however, these machine safeguarding principles have evolved and advanced to keep pace with innovations in manufacturing technology.
Although innovations in manufacturing technology have never remained stagnate, the greatest number of changes in domestic manufacturing technology has occurred during the past three decades. This transitional change was due in part to global competition, which made the use of manually operated machines and processes unprofitable. Global competition has caused labor intensive manufacturing process to be exported to less economically developed countries where employee compensation is lower. Consequently, in order for domestic manufacturers to profitably survive in the United States, they had to incorporate advanced manufacturing technologies and automation techniques which reduced the reliance on labor intensive processes. These advanced manufacturing technologies and automation techniques have placed additional emphasis on the need for advancements in machine safeguarding technologies.
The terms machine guarding and machine safeguarding are often interchanged. They do, however, have distinctly different meanings. The term machine guarding is an older term, generally defined as a physical barrier guard placed over a machine's hazardous operation to prohibit access to the hazardous area. Machine safeguarding is both a more contemporary and more encompassing term. Machine safeguarding can be defined as being either a physical barrier guard or one of the many available types of safeguarding devices. Safeguarding devices can be either mechanically controlled safeguarding devices such as safety gates or electronically controlled safeguarding devices such as safety light curtains. As innovations in manufacturing technology has advanced over the past three (3) decades, the reliance on complex safeguarding devices (bothmechanical &; electronic) has increased and the technology needed to install and service these devices has also greatly increased.
Over the past three decades, four primary innovations in manufacturing technology have had the greatest impact on machine safeguarding technology. These innovations include the evolution: a) from mechanical actuation to hydraulic &; pneumatic actuation, b) from 1st generation to 2nd generation (and beyond) cutting tool technology, c) from 1st generation machine tools to 2nd generation (and beyond) machine tools, and d) from machines controlled by human intelligence to machines controlled by computers. Each of these evolutionary innovations and their resultant effects on safeguarding technology will be discuss separately below.
The first area of manufacturing innovation involve how machine tools were actuated. Machine tools built in the 1960's were primarily actuated mechanically through the use of:
belts &; pulleys,
gears &; transmissions,
clutches, and
flywheels.
Current technologies, however, have replace many of these mechanically actuated machine tools with pneumatic and hydraulic actuated machine tools.
