Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part I - Department of Labor and Industry
Chapter 29 - MECHANICAL APPARATUS-MISCELLANEOUS
Subchapter C - MECHANICAL POWER TRANSMISSION APPARATUS
SPECIFICATIONS
Section 29.121 - Gears and silent chain drives

(1) Gears with a pitch of less than 3/8 inch or a face of less than 1 1/4 inch or a diameter of less than 12 inches and all other gears and silent chain drives making less than six revolutions per minute.

(2) Gears and silent chain drives located within the frame of the machine when the nip or run-in point is more than 12 inches from any opening in the machine lending access to it.

(1) A complete enclosure, or where access to the nip-point is difficult, a partial enclosure, such as a guard solid at the top, ends, and exposed sides down to the bottom of the gear, but open at the bottom.

(2) Band guards around the entire circumference of the gears with side flanges extending to the root of the teeth.

(3) When access to the nip-point is difficult, when there is danger of fire through the accumulation of fly or lint, and when permission is granted by the Department, a nip-point guard is permitted. This guard shall be such that the nip or run-in point is guarded for a distance of at least two inches around the face of each gear and shall be 1/4 inch or less from the gear teeth at its end and extend down to the root of the teeth on the exposed sides of the gears.