1. Machine Guarding
MODULE 19

2. What hazards exist? Crushed by or drawn into equipment
Struck by moving parts
Struck by failed components or particles

3. Key parts of machines
Point of operation: where work is performed on the material, such as cutting, shaping, boring, or forming of stock.
Power Transmission Device: transmits energy to the part of the machine performing the work
Includes flywheels, pulleys, belts, connecting rods, couplings, cams, spindles, chains, cranks, and gears.

4. Key parts of machines Operation Controls: Control mechanisms
Other moving parts: can include reciprocating, rotating, and transverse moving parts, feed mechanisms, and auxiliary parts of the machine

5. Hazards to be Guarded Things to guard include In-running nip points
Rotating equipment
Flying chips or sparks
Belts or gears
Parts that impact or shear

6. Rotating Parts Can grip hair or clothing
Can force the body into a dangerous position
Projecting pieces increase risk

7. In-Running Nip Points Between 2 rotating parts
Between rotating and tangential parts
Between rotating and fixed parts which shear, crush, or abrade

8. Reciprocating Parts
Risk of being struck between stationary and moving part

9. Transverse motion Continuous straight line motion
Worker struck or caught in pinch or shear point

10. Cutting action Direct injury from cutting action
Flying chips or sparks
Saws, drills, lathes, mills

11. Punching action
Ram stamps materials
Danger at point of operation

12. Shearing action Powered blade that shears materials
Hazard at point of operation

13. Bending action Power applied to a slide to stamp/shape materials
Hazard at point of operation

14. Guarding Principles
Prevent contact between hazardous moving parts and body or clothing
Secure guard: not easily removed
Protect from objects falling into machinery
No new hazards: sharp/rough edges
No interference with job/comfort/speed
Allow safe lubrication: without removing guards if possible

15. Guarding Methods Location / distance Guards Fixed Interlocked
Adjustable
Self-adjusting

16. Guarding Methods Devices Presence sensing Pullback Restraint
Safety controls (tripwire cable, two-hand control, etc.)
Gates

17. Guarding Methods Feeding & ejection methods Robots Miscellaneous aids
Automatic and/or semi-automatic feed and ejection
Robots
Miscellaneous aids
Awareness barriers
Protective shields
Hand-feeding tools

18. Fixed Guard Barrier is a permanent part of machine
Preferable over other types

19. Interlocked Guard Stops motion when guard is opened or removed
Interlocked guard on revolving drum

20. Adjustable Guard Barrier may be adjusted for variable operations
What are the drawbacks?
Bandsaw blade adjustable guard

21. Self-Adjusting Guard Adjusts according to size/position of material
Circular table saw self-adjusting guard

22. Pullback Device Cables attached to operator’s hands or wrists
Removes hands from point of operation during danger period
What are the drawbacks?

23. Restraint Device Cables attached to fixed point and wrists or hands
Adjustable to let hands travel in predetermined area
May be accompanied by hand-feeding tools

24. Safety Tripwire Cable
Device located around the perimeter of or near the danger area
Operator must be able to reach the cable to stop the machine

25. Two-Hand Control
Requires constant pressure on both pads to activate the machine
Hands on controls at safe distance while machine is in dangerous cycle

26. Gate Must close fully to protect user before cycle will start
Gate Open
Gate Closed

27. Safeguarding by Location/Distance
Location of hazardous parts that is inaccessible or not a hazard during normal operation
Must maintain safe distance
Training, warning, communication necessary

28. Protective Shields
Protection from flying particles or splashing fluids
Do not protect completely from machine hazards

29. What regulations apply?
29 CFR 1910 Subpart O
29 CFR 1910 Subpart P for hand and portable power tools
API RP Machinery and Tools

30. Machinery and Machine Guarding
29 CFR 1910 SUBPART O

31. Organization Definitions General requirements for all machines
Woodworking machinery requirements
Abrasive wheel machinery
Mills and calenders in the rubber and plastics industries
Mechanical power presses
Forging machines
Mechanical power-transmission apparatus

32. General Requirements
29 CFR

33. (a) Machine guarding
One or more types of guarding to protect from hazards.
Barrier guards
Two-hand tripping devices
Electronic safety devices
Etc.
Affixed to machine where possible
Guard must not cause its own hazard

34. 1910.212(a) Machine guarding Point of operation guarding:
Guarded if exposes employee to injury
According to standards or
Keep any part of body out of danger zone
Hand tools to permit material handling – in addition to guards, not instead
Examples of machines requiring guards on point of operation

35. (a) Machine guarding
Revolving barrels, drums, containers guarded by interlocked enclosure (cannot turn without guard in place)
Exposure to fan blades: guard openings 1/2 inch

36. 1910.212(b) Anchoring fixed machinery
Machines designed for fixed location must be anchored to prevent moving
This pedestal grinder is designed for anchoring, but is not anchored

37. Abrasive Wheel Machinery
29 CFR

38. 1910.215(a) General requirements
Abrasive wheels must be guarded, with exceptions
Guard design dependent on type of work and type of wheel

39. 1910.215(a) General requirements
Work rests:
Rigid, clamped in place securely
Adjusted to within 1/8 inch of wheel
Never adjusted while in motion
Work rest is closely
adjusted

40. 1910.215(b)(9) Exposure adjustment
For type where operator stands in front of opening: Adjustable for decreasing wheel size
Adjustable tongue guard must never be more than ¼ inch from wheel

41. (d) Mounting
Inspect for damage and ring test immediately before mounting
Tap with light nonmetallic implement (screwdriver, wooden mallet)
If sound is dead, cracked ring may not be used
Check spindle speed against maximum for wheel

42. Ring Test

43. Mechanical Power-Transmission Apparatus
29 CFR
Mechanical Power-Transmission Apparatus

44. Organization of 1910.219 (a) General requirements
(b) Prime-mover guards
Flywheels
Cranks and connecting rods
Tail rods or extension piston rods
(c) Shafting
(d) Pulleys

45. Organization of 1910.219 (e) Belt, rope, and chain drives
(f) Gears, sprockets, and chains
(g) Guarding friction drives
(h) Keys, setscrews, and other projections
(i) Collars and couplings
(j) Bearings and facilities for oiling
(k) Guarding of clutches, cutoff couplings, and clutch pulleys

46. Organization of
(l) Belt shifters, clutches, shippers, poles, perches, and fasteners
(m) Standard guards-general requirements
(o) Approved materials
(p) Care of equipment

47. Hazards on Oil and Gas Sites
Machine Guarding

48. Parts Requiring Guarding
Drive belts and shafts – mud pumps and tank area
Pony rods
Rotating parts
Shale shaker
Agitator shafts & couplings
Moving generator parts
(explore)

49. Mud Pumps

50. Shale Shaker

51. Generators

52. Parts Requiring Guarding
Air compressors
Crown sheaves
Kelly bushing – or controls
Rotary chain drive
Air hoist line
Drawworks
Bench grinder wheels

53. Crown Sheaves

54. Kelly and Bushing
Alternative Abatement: STD CH-1

55. Drawworks

56. Parts Requiring Guarding
Belts, drive chains, gears and drives on power and hand tools
Traveling blocks
Sheaves
Cathead?

57. Drilling Line

58. Traveling Block

59. Hoisting Line

60. Safety Responsibilities
Machine Guarding

61. Safety Responsibilities
Management:
Ensure all machinery is properly guarded
Supervisors:
Train employees on specific guard rules in their areas
Ensure machine guards remain in place and are functional
Immediately correct machine guard deficiencies
Employees:
Do not remove guards unless machine is locked and tagged
Report machine guard problems to supervisors immediately
Do not operate equipment unless guards are in place

62. Training Operators/affected employees should receive training on:
Hazards associated with particular machines
How the safeguards provide protection and the hazards for which they are intended
How and why to use the safeguards
How and when safeguards can be removed and by whom
What to do if a safeguard is damaged, missing, or unable to provide adequate protection

63. Hand and Portable Power Tools
29 CFR 1910 Subpart P and 1926 Subpart I

64. Construction vs. General Industry
Construction, alteration, or repair?
Applicable standard depends on type of operations:
1910 Subpart P: Hand and Portable Powered Tools and Other Hand-Held Equipment
1926 Subpart I: Tools – Hand and Power

65. General
Employer is responsible for safe condition of tools and equipment
Including equipment furnished by employee
Compressed air must not be used for cleaning unless:
Reduced to <30 p.s.i.
Only with effective chip guarding and PPE

66. 1910.243(a) Portable powered tools
Portable circular saws >2 in. guarded
Automatic return to covering position
Switches and controls:
constant pressure control for circular and chain saws
other controls for other tools as appropriate

67. 1910.243(a) Portable powered tools
Portable belt sanding machine guarding
Nip points
Unused run of sanding belt
Cracked saws: remove from service
Grounding: Meet Subpart S

68. 1910.243(b) Pneumatic powered tools and hose
Tool retainer to prevent ejection
Airhose designed for applied pressure and service

69. 1910.243 Guarding of portable powered tools
Portable abrasive wheels:
Must be guarded
Ring test and inspection
Explosive actuated fastening tools
Power lawnmowers
Guarding
Controls and shutoff device
Labeling, manuals
Design

70. 1910.244 Other portable tools and equipment
Jacks
Loading and marking
Operation and maintenance
Abrasive blast cleaning nozzles: operating valve and support

71. General requirements
Maintained in safe condition whether furnished by employer or employee
Shall be guarded when designed to accommodate guards
Moving parts that create hazards shall be guarded by one or more methods
Fan openings; anchoring machinery

72. 1926.300 General requirements Abrasive wheel guards
PPE if necessary for objects, particles, gases
Allowable switches by tool type

73. 1926.301 Hand tools Use of unsafe hand tools not permitted
Wrenches shall not be used when jaws are sprung to the point of slippage
Including adjustable, pipe, end & socket wrenches
Impact tools shall be kept free of mushroomed heads
Such as drift pins, wedges & chisels
Wooden handles shall be kept
Free of splinters or cracks
Tight in the tool

74. 1926.302 Power-operated hand tools
Electric power-operated tools
Double-insulated or grounded
Never hold by the cord
Pneumatic power-operated tools
Secure tools, attachments, and muzzle
Compressed air use restrictions
Never hold by the hose
Reduce pressure in case of hose failure

75. 1926.302 Power-operated hand tools
Fuel operated tools
Stop while refueling or servicing
Watch concentrations in enclosed spaces
Hydraulic power tools
Fire-resistant fluids
Safe operating pressures
Powder-actuated tools

76. 1926 Subpart I Organization
Abrasive wheels and tools
Woodworking tools
Jacks
Air receivers
Mechanical power-transmission apparatus