Machine guard power transmission

The earliest set of standards for machine guarding appeared in 1914. The current series of ANSI machine guarding standards (B11 series) began in 1922 with the adoption of the first standard for power presses and foot and hand presses. The first edition of the standard for guarding power transmission apparatus (B15) appeared in 1927. ... 

The U.S. Patent and Trademark Office issued the first patent for an interlock in 1868. The interlock was a mechanical arrangement. The agency issued the first electrical interlock on a power transmission guard in 1923. In 1899, the agency issued a patent for a press guard that prevented the machine from acting if the guard was not fiiUy closed. 

Safeguards include guards, devices, distance, or location. Safeguards for machines fall into two major groups mechanical power transmission safeguards, and point-of-operation safeguards. 

Machines Power Transmission Equipment Guards in place good condition Unguarded dangers Controls - Clearly identified coded - prevent unintended activation - emergency stops near workers Power transmission items guarded Energized equipment lock-out capable ... 

General Requirements for all Machines (Guarding) and 1910.219, Mechanical Power Transmission Apparatus. 

Some individuals in the material handling industry argue that the improvements in conveyor safety have not kept pace with improvements in other machines and processes. Some of the noticeable improvements, however, include full enclosures of pinch points such as chain and sprocket transmissions, perimeter pull cords for emergency stops, audible alarms and a delayed start-up function, pop-out rollers, improved warning labels, and interlock guards that are designed to shut off the power if removed. 

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