MACHINE GUARDING
PRESS BRAKE/ FOLDINGMACHINE
SAFE DISTANCE / SAFE SPEED SAFEGUARD PROGRAM
Machine Guarding
Press Brake / FoldingMachine - Safe Distance / Safe Speed
Safeguard Program
NOTE:OSHA standards provide some specific requirement for various pieces of equipment, but not all. Whether or not a piece of machinery or equipment is specified in the standard, keep in mind --- if there are movements or actions that can affect you when operating the equipment or machine, then it must be guarded in some way.
CLASSIFICATIONS OF SAFE GUARDS
There are many ways to safeguard equipment or machinery. The type of operation, the size or the shape of the stock, the method of handling, the physical layout of the work area, the type of material and the production requirement or limitations will help determine the appropriate safeguarding methods for the individual machine or equipment. Basic classes of safeguards are:
Physical Barrier Guards
Machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, in-running pinch points, rotating parts, flying chips and sparks. There are several different types of physical barrier guards, including:
- Fixed Barrier – provides protection by not permitting access to the point of operation.
- Adjustable Barrier – identical to fixed barrier guards with added adjustability characteristics.
- Interlocked – gates or guards attached to the press frame or bolster are are connected with the press clutch control so that the clutch cannot be activated unless gate is in position to conform to standards.
Guarding Devices
Guarding devices protect operators and other employees, in the machine area, from hazards such as those created by point of operation and in-running pinch points. These devices will disable the equipment or machine if disturbed. They include:
- Presence sensing --- Photoelectrical or radio devices that detect the presence of an operator.
- Safety control --- devices that rely on the operator applying force against them to trip a microswitch that will shut down the equipment, eliminating the hazard.
- Gates --- interlocking devices that will shut down the equipment or machine if they are opened.
Administrative Controls
Administrative controls establish rules and regulations for working around a point of operation and should only be used when all other types of guarding cannot ensure safeguarding. They include establishing safe working rules, such as safe distance or safe speed,and enforcement of these rules. Administrative controls are commonly used when working with press brake / folding equipment (See Distant Safeguarding / / Safe Speed Program located within this section).
SAFEGUARDING POINT OF OPERATION
The point of operation is where the work is actually performed on the material. This includes all components of the mechanical system that transmit energy to the part of the equipment or machine performing the work. A wide variety of these mechanical motions can present hazards. These motions typically create in-running pinch points that must be guarded. These components include:
- flywheels
- belts
- connecting rods
- couplings
- cams
- collars
- chains
- cranks
- gears
- pulleys
- spindles
- shaft ends
Every point of operation less than eight feet from a working surface, which exposes an employee to injury, shall be guarded and meet the following design, construction, application and adjustment requirements. All guards shall:
- Be used to protect all areas of entry to the point of operation not protected by other means or devices.
- Prevent entry of hands or fingers into the point of operation by reaching through, over, under or around the guard.
- In itself, create no hazard or pinch point between the guard and the moving machine part.
- Use fasteners not readily removable by the operator, so as to minimize the possibility of misuse or removal of essential parts.
- Be inspected regularly for damage and integrity.
- Conform to other requirements.
- Attach enclosure die guards to the die shoe or stripper in a fixed position.
- Attach fixed and adjustable barrier guard securely to the frame of the press or to the bolster plate.
- Not be used for manual feeding of materials.
- Conform to the maximum permissible openings listed below.
Distaqnce of opening from point of operation hazard / Maximum width of opening (in inches)
1/2 to 1 1/2 inches / 1/4 inch
1 1/2 to 2 1/2 inches / 3/8 inch
2 1/2 to 3 1/2 inches / 1/2 inch
3 1/2 to 5 1/2 inches / 5/8 inch
5 1/2 to 6 1/2 inches / 3/4 inch
6 1/2 to 7 1/2 inches / 7/8 inch
7 1/2 to 12 1/2 inches / 1 1/4 inch
12 1/2 to 15 1/2 inches / 1 1/2 inch
15 1/2 to 17 1/2 inches / 1 7/8 inch
17 1/2 to 31 1/2 inches / 2 1/8 inch
All devices and gates shall protect the operator by:
- Preventing or stopping normal stroking of the press if the operator’s hands or other body parts are inadvertently placed in the point of operation.
- Requiring the operators to position their hands to machine operating controls and locating such controls at a safe distance from the point of operation that the downward cycle can be completed.
- Enclosing the point of operation before a press stroke can be initiated
Machine Set-up
Prior to operating the power press brake / folding machine, an inspection of the machine should be conducted to insure that the proper die is in place. At all times when the press brake / folding machine is not in operation:
- The controls should be turned off.
- The foot treadle should be removed or placed as near as possible to the unit.
- When the foot pedals are used, they must be properly guarded.
Press Brake Safe Distance / Safe Speed Safeguard Program
Press Brakes /Folding Machinesare excluded from the machine guarding requirement of CFR 1910.217 by Compliance Directive CPL 02-01-025, when guarding and other safe guard devices cannot ensure safeguarding. This directive allows work to be completed by the establishment of a Safe Distance Safeguard Program.
Safeguarding by maintaining a safe distance / safe speed is acceptable if:
- It can be demonstrated that guarding and devices cannot ensure safeguarding.
- It can be demonstrated that power press brake /folding machine point of operation guarded by maintaining a safe distance is limited to a one-time only fabrication of made-to-order or custom-made piece parts or a small quantity run of no more than four hours per month.
- A safety program is established that includes safe work procedures, training, and supervision to ensure that work is performed using safe distance alternatives measures.
- A workplace history of operating power press brakes safely by maintaining a safe distance from the point of operation is documented.
Why standards guard and devices cannot ensure safeguarding
Standard guards and devices work well for high volume production. For small or custom production these types of guards would have to be changed or adjusted for each piece of material. This would pose an undue constraint on the productivity and the use of these guards and devices cannot ensure safeguarding.
Fixed guards would have to be changed for each piece part depending on the material and type of bend being performed. Adjustable barriers, as with the fixed barriers will have to be changed for each piece part and may still leave the point of operation unprotected during parts of the cycle.
Safe guarding devices, such as light curtains, laser guarding or two hand controls,cannot be used because of the materials entering the safe guarding device (causing a system shutdown), the machine cannot be lower to the safe working position to complete the work process, or both hands are needed to control the work material.
Safe Distance
The operator of the power press brake / folding machinewill not approach any closer than necessary and in no case, closer than four (4) inches from the point of operation. This distance is measured from the exterior point of contact of the press brake dies or folding machine bending point to an employee.
When possible a warning barrier or guard shall be attached to the brake press to identify the four (4) inch prohibited zone.
At all times, the operator must have two hands on the work material when Administrative Controls, such as safe distance or safe speed is used.
Safe Speed
At all times, the operator will have two hands on the work material and the unit shall not close faster than 10 mm per second.
Operation of a Press Brake using Safe Distance or Safe Speed
There are many hazards associated with the operation of Power Press Brakes without safe guarding. The following procedures will assist you in identifying and controlling some of these hazards.
STEP 1–Obtain the safe device by-pass key for the shop foreman.
STEP 2 – Set up the materials to be fabricated on the retrieve table.
- Hazards
Improper handling could result in the worker receiving cuts or lacerations from contact with the materials or strains from not properly positioning the materials and their body.
- Safe Operating Procedures
- Clear area of any excess debris or materials that are not to be used.
- Check the weight of the material and get help if necessary.
- Be sure to keep area free of debris during operation.
- Stage the materials in a way to make them easily accessible.
- Wear gloves.
STEP 3 - Place the material in the operating area.
- Hazards
Strains, cuts, or getting a hand or finger caught in the machine. The hazard also exists of getting a body part caught in the machine.
- Safe Operating Procedures
- Hold the material with two hands, keeping thumbs up.
- Workers must never reach into the die or folding area.
STEP 4 - Place foot on the treadle/foot pedal.
- Hazards
Tripping or the possibility of getting a foot caught in treadle/foot pedal.
- Safe Operating Procedures
- Be aware of the treadle/foot pedal position
- Be sure that the body is in proper position and that the helper is also in proper position; the helper should be clear and out of the point of operation at all times.
STEP 5 - Operate the press brake.
- Hazards
There is the potential to get a body part caught in the press or have the material torque out of the worker's hands and strike them or the helper.
- Safe Operating Procedures
- Hold the material with two hands, keeping thumbs up. On press brakes the lower fingers shall be at or behind lower WARNING BARRIER at all times.
- Maintain a solid grip.
- Engage food petal.
- Watch for the material to swing when contact is made.
STEP 6 - Remove foot from the treadle.
- Hazards
Tripping or the possibility of getting a foot caught in treadle/foot pedal
- Safe Operating Procedures
- Maintain a stable body position
STEP 7 - Remove or reposition the material.
- Hazards
Cuts, body strains, or getting a body part caught in the machine or between the material and the machine.
- Safe Operating Procedures
- Hold the material with two hands keeping a firm grip on the material.
- Be sure that both you stay out of the die area.
STEP 8 - Place material on the return table.
- Hazards
It is possible to be struck by materials, have a harmful contact with materials, or cause muscle strain.
- Safe Operating Procedures
- Clear the area of unneeded material.
- Get help when it is needed.
- Keep the area free of debris.
STEP 9 – Repeat steps 2-8 till production run is completed.
STEP 10 – When production run is finished turn safe guarding devices off and return key to shop foreman
Training
Operator Training
Operator training should include:
- The type of hazards that may be encountered and safety controls to minimize those hazards.
- Training in safe related work practices that pertain to press brake / folding machine equipment.
- Function and purpose of all controls associated with the operation of the power press brake / folding machine.
- The function and purpose of hand-feeding tools and when they are required.
- Ability to demonstrate safe operating and exposure prevention procedures.
- Personal Protection Equipment Required.
Helper Training
Helper training should include:
- The type of hazards that may be encountered and safety controls to minimize those hazards.
- Training in safe related work practices that pertain to press brake / folding machine equipment.
- The function and purpose of hand-feeding tools and when they are required.
- Personal Protection Equipment Required.
Retraining
Retraining shall be provided when the following are noted:
- When there is reason to believe that an employee, who has already been trained, does not have the understanding and skill required to work safely,
- When workplace changes present a hazard for which employees have not been trained.
Machine Guarding & Press Brank Safe Distance Safeguard Program Page 1