Subchapter C. MECHANICAL POWER TRANSMISSION
APPARATUS
GENERAL PROVISIONS Sec.
29.111. Definitions.
29.112. Scope.
29.113. Applicability.
29.114. Penalty.
SPECIFICATIONS
29.121. Gears and silent chain drives.
29.122. Pulleys, sheaves and sprockets.
29.123. Belts, ropes and chains.
29.124. Cone pulley belts.
29.125. Belt shifters and stopping devices.
29.126. Shafting.
29.127. Location.
29.128. Friction drives.
29.129. Shaft projections and keyways.
29.130. Collars, couplings and clutches.
29.131. Prime movers.
29.132. Machine control.
29.133. Operating rules.
29.134. Construction of guards.
29.135. Materials and construction of guards.
RECOMMENDATIONS
29.141. Purpose.
29.142. Belt tighteners and shifters.
29.143. Care of belts.
29.144. Belts on overhead pulleys.
29.145. Pulleys.
29.146. Couplings and clutches.
29.147. Shafting, bearings and hangers.
29.148. Oiling and cleaning.
29.149. Power control.
29.150. Hand-operated gears.
Authority The provisions of this Subchapter C issued under the act of June 2, 1913 (P. L. 396, No. 267) (71 P. S. § § 1441—1451); and section 15 of the act of May 18, 1937 (P. L. 654, No. 174) (43 P. S. § 25-15), unless otherwise noted.
Source The provisions of this Subchapter C adopted February 16, 1929; amended through August 1, 1968, unless otherwise noted.
Cross References This subchapter cited in 34 Pa. Code § 5.118 (relating to transportation, machinery, and platforms); 34 Pa. Code § 29.11 (relating to all installations); 34 Pa. Code § 29.181 (relating to all installations); and 34 Pa. Code § 45.11 (relating to mechanical power transmission and machine layout).
GENERAL PROVISIONS
§ 29.111. Definitions.
The following words and terms, when used in this subchapter, have the following meanings, unless the context clearly indicates otherwise:
Flywheels—Flywheels and balance wheels mounted and revolving on crank shaft of engine or other shafting.
Guarded by position—The object so located that contact which may result in injury is unlikely to occur.
Horizontal belt—A belt running in a horizontal direction.
Inclined belt—A belt running in a direction within 60° of the horizontal.
Nip-point belt and pulley guard—A device which encloses the pulley and is provided with round or rolled edge slots through which the belt passes.
Point of operation—That point at which cutting, shaping, or forming is accomplished upon the stock. This term includes such other points as may offer a hazard to the operator in inserting or manipulating the stock in the operation of the machine.
Prime mover—A steam, gas, oil or air engine, a steam or hydraulic turbine, or an electric motor.
Runway—Any permanent runway or platform used for oiling, maintenance, running adjustment or repair work, but not as a passageway.
Self-oiling bearing—A bearing that needs to be oiled only at infrequent intervals, at least for the duration of the shift or working day, so that all oiling may be done when the power is shut off. Ring oiling bearings and candle lubrication are considered self-oiling under these conditions.
Standard railing—A railing not less than 42 inches in height with an additional rail midway between the top rail and the floor or platform level placed not less than 15 inches or more than 20 inches from the point of hazardous contact.
Vertical belt—A belt running in a vertical direction or in a direction within 30° of the perpendicular.§ 29.112. Scope.
This subchapter sets forth rules to safeguard the lives and limbs of workers in industries which use mechanical power transmission apparatus, and places the responsibility of complying with these rules upon both employer and employe.
§ 29.113. Applicability.
This subchapter applies to the following:
(1) All moving parts of equipment used in the mechanical transmission of power, including prime movers, intermediate equipment, and driven machines, excluding point of operation.
(2) Connecting rods, cranks, flywheels, shafting, spindles, pulleys, belts, link belts, chains, ropes and rope drives, gears, sprockets, friction drives, cams, couplings, clutches, counterweights, revolving or reciprocating parts, up to but not including point of operation; also all bolts, keys, set screws, oil cups or similar projections.
(3) The mere technical fulfillment of the requirements of this subchapter does not assure approval of a guard if examination shows lack of practicability or of durability.
(4) The Department may require guards not required by this subchapter if, in it’s opinion, a sufficient hazard exists to warrant this action.
(5) The guarding of all mechanical power transmission apparatus shall conform with the requirements of this subchapter, except that guards installed and accepted by the Department prior to February 16, 1929, need not be replaced unless the hazard so warrants.
§ 29.114. Penalty.
Any person who violates this subchapter or any regulations of the Department or who interferes with the Department or its duly authorized representative in the enforcement of this subchapter or regulations shall be penalized under section 15 of act of May 18, 1937 (P. L. 654, No. 174) (43 P. S. § 25-15).
SPECIFICATIONS
§ 29.121. Gears and silent chain drives.
(a) Gears and silent chain drives shall be guarded, except for the following:
(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.
(b) Gears and silent chain drives shall be guarded in accordance with one of the following methods:
(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.
(c) This section does not apply to hand-operated gears used only to adjust machine parts and which do not continue to move after the handpower is removed. However, the guarding of these gears is highly recommended.
§ 29.122. Pulleys, sheaves and sprockets.
(a) Flange pulleys located 6 feet or less above the floor or working platform shall be guarded except for the following:
(1) Flange pulleys carrying belts less than 1 inch in width and laced with approved fasteners.
(2) Flange pulleys located within the frame of the machine and guarded by position.
(3) Flange pulleys located so that the point of contact is guarded by position, if the belt is laced with approved fasteners.
(b) Flat or crowned pulleys located six feet or less above the floor or working platform shall be guarded, except for the following:
(1) Flat or crowned pulleys carrying belts less than two inches single ply or 1 1/2 inches double ply and laced with approved fasteners.
(2) Flat or crowned pulleys located within the frame of the machine and guarded by position.
(3) Flat or crowned pulleys located so that the point of contact is guarded by position and the belt is laced with approved fasteners.
(4) When there is a danger from fire through the accumulation of fly or lint, flat or crowned pulleys carrying belts other than transmission or machine driving belts, located outside of machines and less than four feet center to center if belts are provided with approved fasteners.
(c) Pulleys carrying circular belts located 6 feet or less above the floor or working platform shall be guarded, except for the following:
(1) Pulleys carrying belts less than 1/4 inch in diameter and fastened with approved fasteners.
(2) Pulleys located within the frame of the machine and guarded by position.
(3) Pulleys located so that the point of contact is guarded by position, if the belt is laced with approved fasteners.
(d) Pulleys serving as balance wheels, such as on punch presses, on which the point of contact between the belt and pulley is more than 6 feet from the floor or platform may be guarded with a disc covering the spokes.
(e) When the bearings are not self-oiling and the clearance between the pulley and bearing on line and jack shafting is 18 inches or less, pulleys over 6 inches in diameter shall be completely guarded on the side nearest the bearing, and keyways in the shaft between such pulley and bearing shall be properly filled in or the shaft shall be enclosed.
(f) When there are overhanging pulleys on line, jack or counter shaft with no bearing between the pulley and the outer end of the shaft, a guide to prevent the belt from running off the shaft shall be provided.
(g) Cracked, broken, or welded pulleys, unless the welded pulleys are perfectly balanced, shall not be used. Pulleys shall be designed for the maximum service that they are expected to give.
(h) Sheaves located 6 feet or less above the floor or working platform shall be guarded, except for the following:
(1) Sheaves located within the frame of the machine and guarded by position.
(2) Sheaves located so that the point of contact is guarded by position, and the belt is laced with approved fasteners.
(i) Sprockets located 6 feet or less above the floor or working platform shall be guarded, except for the following:
(1) Sprockets located within the frame of the machine and guarded by position.
(2) Sprockets located so that point of contact is guarded by position.
(j) The guarding of pulleys, sheaves and sprockets shall be by one of the following methods:
(1) By full enclosure when belt, rope or chain is entirely enclosed.
(2) By partial enclosure extending from the bottom to at least the top of the pulley, sheave or sprocket on all unprotected sides except the tops and bottoms of those carrying vertical belts, ropes or chains. For pulleys, sheaves or sprockets, carrying horizontal or inclined belts, ropes or chains, a guard placed over the pulley, sheave or sprocket in exactly the same manner as for vertically installed equipment may be used.
(3) By standard railing enclosure when acceptable to the Department.
§ 29.123. Belts, ropes and chains.
(a) Belts located 6 feet or less above the floor or working platform shall be guarded except for the following:
(1) Vertical belts fastened with approved fasteners.
(2) Horizontal or inclined single ply belts less than 2 inches in width and double ply belts less than 1 1/2 inches in width if the belts are fastened with approved fasteners.
(3) Belts located within the frame of the machine and guarded by position.
(4) Horizontal or inclined belts so located that the run of the belt is guarded by position.
(5) Belts and pulleys of grinding machines used in the manufacture of aluminum or bronze powder if they are guarded by one of the following methods:
(i) Eliminate metal lacers in belts and guard pinch point of pulley and belt.
(ii) Eliminate metal lacers and provide in lieu of pinch point guard a belt shifter which is of a type that in itself protects the pinch point of pulley and belt.
(6) Horizontal or inclined belts, not including transmission or machine driving belts, running or pulleys less than 4 feet center to center and laced with approved fasteners, when there is a danger from fire through the accumulation of fly or lint.
(b) Overhead belts, ropes and chains running over passageways or machines shall be guarded when, in the judgment of the Department, sufficient hazard exists.
(c) Cotton or fabric belts whenever used shall be guarded.
(d) When the guards for pulleys, sheaves or sprockets carrying vertical or inclined belts, ropes or chains which run through the floor or working platform are located more than 4 feet above the floor on working platform belt, ropes or chains shall be guarded.
(e) All ropes or chains located 6 feet or less above the floor or working platform shall be guarded, except for the following:
(1) Vertical ropes or chains.
(2) Ropes or chains located within the frame of the machine and guarded by position.
(3) Horizontal or inclined ropes or chains so located that the run of the rope or chain is guarded by position.
(4) When there is a danger from fire through an accumulation of fly or lint, horizontal or inclined ropes or chains, not including transmission or machine driving ropes or chains, running on pulleys or sprockets less than four feet center to center.
(f) American and Continuous System Rope drives, so located that the conditions of the rope, particularly the splice, cannot be constantly and conveniently observed, shall be equipped with a telltale device, preferably electric bell type that gives a warning when the rope begins to fray.
(g) The guarding of belts, ropes and chains shall be by one of the following methods:
(1) Vertical belts, ropes and chains when required to be guarded shall be enclosed to the upper pulley, sheave or sprocket guard or to a height of at least 6 feet from the floor or working platform when the guard is not more than 4 inches from the belt, rope or chain at any point, or to a height of 5 feet if it is between 4 inches and 12 inches from the belt, rope or chain at any point. Guarding by standard railing may be used when approved by the Department if the railing is at least 15 inches but not over 20 inches from the belt, rope or chain at all points.
(2) Inclined belts, ropes and chains shall be arranged in such a manner that a minimum clearance of 6 feet 6 inches is maintained between the belt, rope, or chain, and the floor at any point outside the guard.
(3) Horizontal belts, ropes, and chains shall be guarded as follows:
(i) Horizontal belts, ropes and chains shall be guarded to a height of at least 6 feet or to the top run of the belt, rope or chain. This guard may be an enclosure on all unprotected sides or a standard railing, when approved by the Department, placed at least 15 inches and not more than 20 inches from the belt, rope or chain at all points.
(ii) When the upper and lower runs of horizontal belts, ropes or chains are so located that passage of persons between them would be possible, passage shall be according to any of the following:
(A) Completely barred by standard guardrails or other barriers.
(B) When passage is regarded as necessary there shall be a platform over the lower run guarded on either side by a complete railing, completely filled with wire mesh or other filler, or by a solid barrier. The upper run shall be guarded to prevent contact either by the worker or by objects carried by him.
(4) Overhead belts, ropes and chains shall be guarded as follows:
(i) Horizontal and inclined belts, ropes or chains shall be guarded the entire run of the belt, rope or chain and follow the run of the pulley to the ceiling or to be carried to the nearest wall.
(ii) Vertical belts, ropes and chains running over a lower pulley more than 6 feet above the floor or working platform shall be guarded around the bottom and up to a distance equal to a height of half the distance between pulleys.
§ 29.124. Cone pulley belts.
(a) When cone pulleys are located less than 3 feet from the floor or working platform, the cone pulley and belt shall be guarded to a height of three feet regardless of whether the belt is shifted by a belt shifter or by hand.
(b) All belts shifted by hand shall be fastened with approved fasteners.
§ 29.125. Belt shifters and stopping devices.
(a) Belt shifters. Shifters with handles shall be provided for all tight and loose pulleys. The shifter handle shall be located outside the guards. Tight and loose pulleys on all new installations made after February 16, 1929, shall be equipped with a permanent belt shifter provided with mechanical means to prevent the belt from creeping from the loose to the tight pulley.
(b) Location. Belt shifters shall be rounded and located as far as possible from danger of accidental contact but within easy reach of the operator. Operators shall be able to stop machines from any operating position. When belt shifters are not located directly over the machines or bench or over the passageway they shall be at least 6 feet from the floor.
(c) Locking device. Mechanical belt shifters shall be equipped with a positive locking device which shall be normally in the off position.
(d) Overhead shifters. Shifters and disengaging levers when suspended overhead shall be so balanced and hung that by their own weight the belt is kept on the loose pulley or in a disengaged position.
(e) Tighteners. Suspended counterbalanced tighteners and all of its parts shall be of substantial construction and securely fastened, and the bearing shall be securely capped. Means shall be provided to prevent tighteners from falling in case the belt breaks. This may be accomplished by securely fastening cables or chains of sufficient strength to the tightener and to the roof, or some substantial object above, to prevent it from falling far enough to strike a person.
(f) Encasing. When suspended counterweights are used in connection with belt tighteners and are not guarded by location they shall be so encased as to prevent accidents.
§ 29.126. Shafting.
(a) Endwise movement. Each continuous line of shafting shall be secured in position against excessive endwise movement.
(b) Endwise thrust. Vertical and inclined shafts shall be secured in position against endwise thrust.
(c) Over driveway. Whenever shafting extends over a driveway it shall be protected unless the shaft and any pulleys, gears or other equipment fastened to it are located 15 feet or more above the driveway.
(d) Under machines. Shafting under bench machines shall be enclosed by a stationary casing or by a trough at the sides and the top, or the sides and the bottom as the location requires. The sides of the trough shall come to within at least 6 inches of the underside of the table, or if shafting is located near the floor to within 6 inches of the floor. In each case the sides of the trough shall extend at least 2 inches above or below the shafting as the case may be.
(e) Guard. All shafting located less than six feet above the floor or working platform shall be guarded in accordance with subsection (g) except for the following:
(1) Shafting accessible for a distance of less than 2 feet between bearings, clutches, handwheels, pulleys, gears, sprockets or sheaves.
(2) Shafting within the frame of the machine when guarded by position.
(f) Shaft ends. Shaft ends less than 6 feet above the floor or working platform and 4 or more inches beyond outside parts of the machine or transmission shaft equipment shall be removed or enclosed with a stationary cover. When they are less than four inches from other equipment, such shaft ends shall be polished smooth or be enclosed with a stationary cover.
(g) Method of guarding. The guarding of shafting shall be by one of the following methods:
(1) An enclosure which may be by sheet metal in the shape of an inverted U open at the bottom.
(2) Standard railing if acceptable to the Department.
§ 29.127. Location.
(a) Guarding. Transmission equipment located in transmission basements, towers or rooms used exclusively for power transmission equipment shall be guarded in accordance with the requirements of this subchapter or the basements shall be locked at all times when machinery is in motion, so that access may be had only upon application to the superintendent or his agent. An additional key may be kept under glass for emergency use. The key shall be so located as to require the breaking of glass to get the key.
(b) Set screws. Set screws shall be made flush or enclosed regardless of the plan adopted to comply with subsection (a).
(c) Illumination. The intensity of illumination shall conform with the requirements of Chapter 27 (relating to lighting).
(d) Oiling. The route followed by the oiler shall be protected in such manner as to prevent accidents, and shall be dry, firm and level.
§ 29.128. Friction drives.
(a) The drive point of all friction drives when exposed to contact shall be guarded.
(b) Arm or spoke friction drives and web friction drives with holes in the web shall be entirely enclosed.
(c) Projecting bolts on friction drives when exposed to contact shall be guarded.
§ 29.129. Shaft projections and keyways.
(a) Set screws wherever located shall be made flush or enclosed.
(b) Revolving projections on shafting and shaft equipment such as keys and bolts and grease cups shall be enclosed by a cylindrically smooth enclosure or made flush, except for bolts or grease cups located in the hubs or rims of pulleys, collars or couplings which do not project beyond the two planes formed by the rims of the pulley, collar or coupling.
(c) Keyways in the ends of shafting less than 6 feet above the floor or working platform, which project more than 2 inches beyond the bearings, or adjacent parts of a machine, shall be plugged so as to effect a smooth shaft, or they shall be enclosed.
§ 29.130. Collars, couplings and clutches.
(a) Collars. Revolving collars, including split collars, shall be cylindrical, and screws or bolts used in collars shall not project beyond the largest periphery of the collar, or they shall be encased.
(b) Couplings. Shaft couplings when located 7 feet or less above the floor or working platform or within less than 18 inches from the hand oil bearings shall be so constructed as to present no hazard from bolts, nuts, set screws, or revolving surfaces or shall be enclosed by a cylindrically smooth enclosure.
(c) Clutches. Clutches or clutch pulleys having projecting parts, when the clutches or clutch pulleys are located 7 feet or less above the floor or working platform or when they are less than 18 inches from hand oil bearings, shall be enclosed by a stationary guard constructed in accordance with this subchapter. However, when clutches, cutoff couplings or clutch pulleys are so located within a machine or otherwise guarded by location, compliance with the requirement of this section shall be within the discretion of the Department.
(d) Handles. Clutch handles shall be rounded and located as far as possible from danger but within easy reach of the operator. Control handles shall be so arranged that the operator can stop the machine from the usual operating position. The clutch handle shall be located outside the guard when clutch is guarded.
§ 29.131. Prime movers.
(a) Flywheels. Flywheels located so that any part is 6 feet or less above floor or platform shall be guarded in one of the following ways:
(1) With an enclosure of sheet, perforated or expanded metal, or woven wire.
(2) With guardrails placed not less than 15 inches or not more than 20 inches from the rim. When the flywheel extends into a pit or is within 12 inches of the floor, a standard toeboard shall be provided.
(3) When the upper rim of a flywheel protrudes through a working floor it shall be entirely enclosed or surrounded by a guardrail and toeboard.
(4) For flywheels with smooth rims five or less feet in diameter, when the preceding methods cannot be applied, a disc attached to the flywheel in such manner as to cover the spokes of the wheel on the exposed side and present a smooth surface and edge, at the same time providing means for periodic inspection. An open width may be left between the outer edge of the disc and the rim of the wheel if desired to facilitate turning the wheel over. When a disc is used the keys or other dangerous projections not covered by the disc shall be cut off or covered.
(5) An adjustable guard to be used for starting the engine or for running adjustments may be provided at the flywheel of gas or oil engines. A slot opening for the jack bar is permitted. This does not apply to flywheels with solid web centers.
(b) Crank and connecting rods. Crank and connecting rods when exposed to contact shall be guarded.
(c) Tail rods. Tail rods or extension piston rods shall be guarded by a complete enclosure or by a guardrail on the sides and the end with a clearance of not less than 15 inches when the rod is fully extended.
(d) Governor balls. Governor balls 6 feet or less from the floor or working platform, when exposed to contact shall be provided with an enclosure extending to the top of the governor balls when at its highest position.
§ 29.132. Machine control.
(a) Unless all machinery can be easily seen from the control station, effective signals shall be provided which give ample warning before starting the machinery.
(b) Emergency stops or switches properly marked and easily accessible shall be provided in each room, section or department by which each complete and separate unit of power transmission may be quickly stopped.
§ 29.133. Operating rules.
(a) The hand dressing of belts while driving machinery is prohibited.
(b) Belts shall not be replaced on pulleys or taken off pulleys by direct hand method while the pulleys are in motion.
(c) The cleaning and oiling of machinery while in motion is prohibited in all places if exposure to hazardous contact is involved.
§ 29.134. Construction of guards.
(a) Materials. Guards or enclosures shall be constructed of cast iron, expanded metal, perforated or solid sheet metal, or wire mesh on a frame of angle iron or iron pipe securely fastened to the floor or to the frame of the machine. Existing guards may be allowed to remain in position if, in the judgment of the Department, they afford adequate protection.
(b) Burrs. Metal shall be free from burrs and sharp edges.
(c) Wire mesh. Wire mesh shall be of the type in which the wires are securely fastened at each cross point either by welding, soldering, or galvanizing, except in case of diamond or square wire mesh made of No. 14 gauge wire, 3/4 inch mesh or heavier.
(d) Uprights. The uprights used for supports shall be of angle iron one inch by one inch by 1/8 inch to 1 1/2 inches by 1 1/2 inches by 3/16 inch; iron pipe 3/4 inch to 1 1/2 inches inside diameter, or construction of equivalent strength. The sizes may vary between the above limits according to the weight and size of the guards and their location in respect to aisles and the possibility of being damaged by moving equipment. There shall be no unsupported panels of guards of greater dimensions than 42 inches.
(e) Filling material. The filling material between the supports of a guard shall be as follows:
(f) Fastening. The filling materials shall be fastened to the supports by one of the following methods:
(1) Angle iron supports. By means of 3/4 inch by 1/8 inch flat iron fastened to the angle by means of 3/16 inch bolts or rivets, placed at intervals not exceeding ten inches, or by wooden strips one inch by one inch fastened to the angles by means of 3/16 inch bolts; or by other methods providing equivalent strength. Perforated or sheet metal shall be either bolted or riveted directly to the angle, or spot welded.
(2) Piping. Piping shall be clamped.
(g) Standard railing. When railings are used for the guarding of machinery, there shall be compliance with the following requirements:
(1) Railings shall be not less than 42 inches in height provided with an intermediate rail between the toprail and the floor, and shall be constructed in a permanent and substantial manner, smooth and free from protruding nails, bolts and splinters.
(2) If constructed of pipe, they shall be not less than 1/4 inches inside diameter.
(3) If constructed of structural metal bars, they shall be the equivalent of 1 1/2 inches by 1 1/2 inches by 3/16 inch angles.
(4) If constructed of wood, the posts shall be not less than 2 inches by 4 inches or the equivalent. Toprailings shall be not less than 2 inches by 4 inches or 1 inch by 4 inches if another board of not less than 1 inch by 4 inches is securely nailed to the sides of the posts and to the toprail. Center railings shall be not less than 1 inch by 4 inches.
(5) Posts and uprights shall be spaced not more than 8 feet apart.
(6) The rails, when of metal shapes, metal bars or wood, shall be placed on that side of the posts which afford the greater support and protection.
(7) When panels are fitted with substantial expanded metal or wire mesh, the middle rails may be omitted.
(8) Toeboards shall be 6 inches or more in height of wood, metal or of metal grill not exceeding one inch mesh. Toeboards at flywheel pits should be placed as close to the edge of the pit as possible.
(h) Wood guards. Wood guards may be used in chemical industries or in construction work when fumes or other manufacturing conditions may cause rapid deterioration of metal guards. In all other industries the use of wood guards is prohibited except by special permission of the Board.
Cross References This section cited in 34 Pa. Code § 29.135 (relating to materials and construction of guards).
§ 29.135. Materials and construction of guards.
(a) Wood shall be sound, tough and free from any loose knots.
(b) Guards shall be made of planed lumber not less than 1 inch rough board measure and edges and corners rounded off.
(c) Wood guards shall be securely fastened together with wood screws, hard wood dowel pins, bolts or rivets.
(d) While no definite dimensions are given under this heading for framework or filler materials, wood guards shall be equal in strength and rigidity to metal guards specified in § 29.134(d) and (e) (relating to construction of guards).
(e) Construction of standard wood railings shall be according to the requirements of § 29.134(g).
(f) Machinery required to be guarded in the slate industry shall be equipped with guards of slate construction at least one inch in thickness except where the installation of the guards prevents proper light from being shed on any operation.
(g) Guards for horizontal overhead belts, ropes and chains shall be according to the following specifications:
(1) Guards for horizontal overhead belts, ropes and chains shall run the entire length of the belt, rope or chains and follow the line of the pulleys or sprockets to the ceiling or be carried to the nearest wall, thus enclosing the belt, rope or chain effectively. When belts, ropes or chains are so located as to make it impracticable to carry the guard to the wall or ceiling, construction of the guard shall be such as to enclose completely the top and bottom runs of the belt, rope or chain and the face of pulleys or sprockets.
(2) The guard and all its supporting members shall be securely fastened to the wall or ceiling by gimlet-point lag screws or through bolts. In case of masonry construction, expansion bolts shall be used. The use of bolts placed horizontally through floor beams or ceiling rafters is recommended.
(3) Suitable reinforcements shall be provided for the ceiling rafters or overhead floor beams when such is necessary, to sustain safely the weight and stress likely to be imposed by the guard. The interior surface of all guards, by which is meant the surface of the guard with which a belt, rope, or chain comes in contact, shall be smooth and free from all projections of any character, except when construction demands it; protruding shallow roundhead rivets may be used. Overhead belt guards shall be at least 1/4 wider than the belt which they protect, except that this clearance need not in any case exceed 6 inches on each side. Overhead rope drive and block and roller-chain-drive guards shall be not less than 6 inches wider than the drive on each side. In overhead silent chain-drive guards where the chain is held from lateral displacement on the sprockets, the side clearance required on drives of 20 inch centers or under shall be not less than 1/4 inch from the nearest moving chain part and on drives of over 20 inch centers a minimum of 1/2 inch from the nearest moving chain part.
(4) In overhead rope or chain guards a side guard member of the same solid filling material shall be carried up in a vertical position 2 inches above the level of the lower run of the rope or chain drive and 2 inches within the periphery of the pulleys which the guard encloses thus forming a trough. These side filler members shall be reinforced on the edges with 1-1/2 inch by 1/4 inch flat steel, riveted to the filling material at not greater than 8 inch centers; the reinforcing strip shall be fastened or bolted to all guard-supporting members with at least one 3/8 inch rivet or bolt at each intersection, and the ends shall be secured to the ceiling with lag screws or bolts.
(h) A disc guard shall consist of a sheet metal disc not less than No. 22 gauge fastened by U-bolts or rivets to spokes of pulleys, flywheels, or gears. When possibility of contact with sharp edges of the disc exists, the edge shall be rolled or wired. In all cases the nuts shall be provided with lock nuts which shall be placed on the unexposed side of the wheel.
(i) U-guards shall be constructed of materials specified in § 29.134 (e). Edges shall be smooth and if the size of the guard requires, these edges shall be reinforced by rolling, wiring, or by binding with angle or flat iron.
(j) The following table gives sizes of materials to be used and general construction of guards for belts ten inches or more in width. No material for overhead belt guards shall be smaller than that specified in this table for belts ten inches wide, even if the belt is less than ten inches in width. However, No. 20 gauge sheet metal may be used as a filler on guards for belts less than ten inches wide. Expanded metal, because of the sharp edges, should not be used as a filler in horizontal belt guards:
RECOMMENDATIONS
§ 29.141. Purpose.
The provisions of § § 29.141—29.150 (relating to recommendations) are not mandatory but are suggestions, which, if put into practice, will be of benefit in accident prevention work. They may also help to clarify some of the provisions of this subchapter.
§ 29.142. Belt tighteners and shifters.
(a) Belt poles. The use of belt poles as substitutes for mechanical belt shifters is not recommended. When necessity compels their use they should be of sufficient size to enable workmen to grasp them securely. A two inch diameter or one and one-half inch by two inch cross section is suggested. Poles should be smooth and preferably of straight-grained hardwood, such as oak or hickory. The edge of rectangular poles should be rounded. Poles should extend from the top of the pulleys to within about 40 inches of the floor or working platform.
(b) Belt perches. When loose pulleys or idlers are not practicable, belt perches in form of brackets, rollers, and the like, should be used to keep idle belts away from the shafts. Perches should be substantially made and so designed that the shipping of belts to and from them may be safely accomplished.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.143. Care of belts.
(a) Quarter twist. Quarter twist belts when installed without an idler may be used on drives running in one direction only. They run off a pulley when direction of motion is reversed.
(b) Inspection. Inspection should be made of belts, lacings and fasteners and such equipment kept in good repair.
(c) Static electricity. The hazard of static electricity from belts should be carefully considered when explosives, explosive dust, flammable vapors or flammable liquids exist. Static electricity may be removed from belts by means of metallic flexible tooth combs the same width as the belt. One comb should be placed within 10 inches of the line of contact where the belt leaves each pulley or flywheel. These combs should be in contact with and placed transversely to the belt and also be well grounded with No. 12 insulated copper wire. The teeth of the comb should point in the direction of the belt motion. Other effective methods may be used.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.144. Belts on overhead pulleys.
(a) Belt pole. A belt pole should be used to throw off or put on belts.
(b) Unshipping. In unshipping a belt, it should always be thrown off the driving pulley, not the driven one.
(c) Care. It is advisable to have one experienced man to take care of overhead belts and put them on and take them off pulleys.
(d) Belt perches. Belts should not be allowed to ride on shafting but should be held from the shafting either by loops or belt perch.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.145. Pulleys.
(a) Alignment. Pulleys should be kept in proper alignment to keep belts from running off.
(b) Crown-faced. Both driving and driven pulleys carrying a nonshifting belt should have crowned faces.
(c) Cast iron. Cast iron pulleys should be tested frequently with a hammer to disclose cracks in rim or spokes. It should be borne in mind that the sound is usually very different if the belt is or is not on the pulley. Pulleys with small pieces broken out of rim should not be used. The rough edges formed by pieces broken out of the pulley rim offer a decided accident hazard in case any one should come in contact with the rough edge of the pulley rim. Considerable unnecessary wear on the belt is also caused.
(d) Split. Split pulleys should be inspected to ascertain if all bolts holding together the sections of the pulley are tight.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.146. Couplings and clutches.
(a) The shifting part of jaw clutches and the shifting or mechanism part of the friction clutch coupling should be attached to the driven shaft, namely, the shaft that is idle when clutch is disengaged.
(b) Clutch shifters of the same type in each shop should move in the same direction to stop machines, namely, either all right or all left. This does not apply to friction clutches on the counter shaft carrying two clutch pulleys with open and crossed belts, respectively. In this case the shifter handle has three positions and the machine is at a standstill when the clutch handle is in the neutral or center position.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.147. Shafting, bearings and hangers.
(a) Shafting should be kept in alignment, free from rust and excessive oil or grease.
(b) When explosives, explosive dusts, flammable vapors or flammable liquids are present, the hazard of static sparks from shafting should be carefully considered. Static electricity may be removed by means of a spring copper brush in contact with the shafting. This brush should be well grounded through No. 12 insulated copper wire. Other effective methods may be used.
(c) Bearings should be kept in alignment and properly adjusted.
(d) Hangers should be inspected to make certain that all supporting bolts and screws are tight and that supports of hanger boxes are properly adjusted.
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.148. Oiling and cleaning.
(a) Oiling should be done only by an authorized person. He should wear tightfitting clothing and should use a can with a long spout to keep his hands out of danger. Drip pans and cups should be securely fastened.
(b) Self-lubricating bearings are recommended.
(c) Oilers’ runways and platforms should conform with the requirements of Chapter 47, Subchapter G (relating to railings, toeboards, open-sided floors, platforms and runways).
(d) When ladders are used for oiling or repairing they shall be equipped with safety locks or antislip devices at the bottom. Reference should be made to Chapter 21 (relating to ladders).
Cross References This section cited in 34 Pa. Code § 29.141 (relating to purpose).
§ 29.149. Power control.
(a) Among the methods used for power control are motor switches, friction clutches, belt shifters, and engine stops. The means for controlling power should be positive and should be so arranged as to permit operation from a point not more than 100 feet from any machine driven from the source of power in question. It is highly advisable to arrange the stations within 50 feet of any machine. There are cases, as for example in the steel industry, when a greater distance from the machine becomes necessary.
(b) It is advisable to mark the stop station with a mark easily distinguishable; green bands on posts and green circles on walls are recommended, together with a sign ‘‘Stop Station’’ or ‘‘Emergency Stop.’’ A light of characteristic color should be added in shops where night work is carried on.
(c) Electrical safety devices should operate by the opening of a normally closed circuit. Any failure of the current or device will thus be indicated by the stopping of the prime mover. It is advisable to test such devices daily by shutting off the power at noon or night by such means.
Cross References This section cited in 34 Pa. Code § 29.41 (relating to purpose).
§ 29.150. Hand-operated gears.
Hand-operated gears need not be equipped with guards. Quite frequently, however, such gears are operated by a short lever or crank, and when the operator braces himself against the frame of the machine he may come in contact with the gears. It is always good practice to look into this matter carefully and whenever there is the slightest chance of injury, it is well to provide guards.
Cross References This section cited in 34 Pa. Code § 29.41 (relating to purpose).
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