Pennsylvania Statutes Title 52 P.S. Mines and Mining § 690-271. Safeguards for mechanical equipment

(a) Locking.--The cutting devices of mining machines shall be locked securely by mechanical means or electrical interlocks while the machines are parked or being trammed. Loading machines shall not be trammed with loading arms in motion except when loading materials.

(b) Guarding.--Belt chain or rope drives and the moving parts of machinery which are within seven feet of the floor, ground or platform level, unless isolated, shall be guarded adequately. Repair pits shall be kept covered or guarded at all times when not in use. Machinery shall not be lubricated or repaired while in motion, except where safe remote lubricating devices are used. Machinery shall not be started until the individual lubricating or repairing it has given a clear signal. Guards that have been removed shall be replaced before the machinery is again put into use. Provisions shall be made to prevent accumulation of spilled lubricants.

(c) Grinders.--Mechanically operated grinding wheels shall be equipped with safety washers and substantial retaining hoods covering two-thirds of the circumference of the wheel and goggles or eye shields shall be used. Where stationary grinders are used, a tool rest shall be provided and the clearance between the wheel and tool rest shall not exceed one thirty-second of an inch.