OH&S Press Setting

The following documents are historical in nature and do not purport to comply with current safety or other legislation.  They are supplied for general information only and may be used as a guide in preparing your own information and assessments that should be specifically tailored for each machine installation.

General Press Maintenance
Key or Friction Clutch

 

Daily Monthly Yearly
Check condition and operation of all guards (and record) 1a *
Check lubrication system and top up reservoir 2 *
Drain air filter and top up air lubricator *
Check brake for correct stopping point 3 *
Check brake interlock mechanism *
Check air lines and tanks for leaks *
Check all screws and bolts for tightness *
Check electrical controls for correct operation *
Check limit switches for correct position and operation *
Periodical examination of machine and attachments 1b *
Check oil lines for flow *
Check air pressure relief valves for operation *
Check clutch and brake parts for wear and condition 4 *
Check dual solenoid valve and clean and replace seals *
Check crank and flywheel bearings for wear and lubrication 5 *
Check ball seat clearances 5 *
Check die cap for seating and bolts for condition *
Check crankshaft and frame for cracking *
Check clearances on slide gibs or V strips *
Check tracking of slide perpendicular to bedplate 6 *
Check slide face and bedplate for parallelism 6 *
Check die cushion seals (where fitted) *
Check flywheel brake (where fitted) *
Check tie bar tension (where fitted) *

 

 

1   The Aust Standard (AS1219 Power Presses – Safety Requirements) requires certain checks for power presses.
(a) a sheet must be attached to the press and the condition of the guard must be checked after each die change, and at the beginning of each shift.  Information must be recorded on a sheet attached to the press, including the name of the inspector and his function.
(b) the press and guards must be examined by a competent person at regular intervals not exceeding 12 months.  The records of the examination must list the items examined and be signed and retained.
2   On manual systems, give one shot every 2 hours – use heavy 220 centistoke oil with “tackiness” additive.  On air lubricators use a light 30 to 40 centistoke oil (sewing machine).
3   The brake should be stopping at top dead centre plus or minus 15 degrees.
4   Friction clutch and brake linings should be replaced at 1.5 mm thickness for bonded plates or 6 mm for non-bonded plates.  Clutch keys and splined bushes should be replaced when the wear faces are pitted, or the edges start to radius.  The spring should be replaced when the key is replaced.  The brake band or shoe lining should be replaced at 3 mm.
5   Clearances over 0.2 mm should be referred to John Heine staff.
6   Out of tolerance of more than 0.1 mm per 300 mm should be referred to John Heine staff.

Note: When in doubt, contact the John Heine Service Department on (02) 9772 5013

General Guillotine Maintenance

 

Daily Monthly Yearly
Lubricate all oiling points (or actuate pump if fitted) 1 *
Check brake for correct stopping point 2 *
Check condition of blades *
Check height of clamp beam from table 3 *
Check condition of all guards *
Check all screws and bolts for tightness *
Check electrical controls for correct operation *
Check gearwheel bearing is being lubricated *
Check oil lines for flow *
Check clearances on shear beam gibs *
Check eccentric to strap clearance 4 *
Check all bearings for wear and lubrication 5 *
Check clutch and brake parts for wear and condition 6 *
Check legs, shear beam and table for cracking *

 

1   Use heavy 220 centistoke oil (preferably with “tackiness” additive).
2   The brake should be stopping the beam at top dead centre plus or minus 5 degrees.
3   Height should be no more than 6 mm to prevent fingers from entering clamp or cutting areas
4   Clearances over 0.5 mm should be referred to John Heine staff.
5   Clearances over 0.3 mm should be referred to John Heine staff.
6   Clutch keys and splined bushes should be replaced when the wear faces are pitted, or the edges start to radius.  The spring should be replaced when the key is replaced.  The brake band or shoe lining should be replaced at 2.5 mm.

Note: When in doubt, contact the John Heine Service Department on (02) 9772 5013

Risk Items Typical of Power Presses

 

Hazard Risk Control Measures
Trapping of fingers in die area Possible amputation of operator’s fingers in die Should only use press when an interlocked die guard is fitted.  Daily inspection of condition of safety items is required.
Rotation of crankshaft when brake not adjusted correctly Possible amputation of operator’s fingers in die Brake interlock is provided to arrest motion
Brake interlock Possible amputation of operator’s fingers in die Daily inspection to check for correct operation
Clutch key jammed in engaged position Possible amputation of operator’s fingers in die Regular inspection by competent person of clutch components to detect wear or “bell-mouthing” of pocket
Flywheel bush seizing Possible amputation of operator’s fingers in die Regular lubrication of plain bush (or upgrade to ball races where possible)
Noise from press and work piece Long term hearing damage to operator and others in the vicinity Ear protection should be worn or the machine should be isolated in an enclosure
Repetitive movements in actuating guard, treadle and in moving products Risk to operator Ergonomic layout for parts (consideration of air operated die guard)
Tommy bar left in crankshaft Injury due to bar being thrown out when press is stroked Should not be used unless self ejecting type
Trapping of fingers in rotating parts Risk of partial amputation or spraining of fingers. Machine must be switched off and isolated before removing flywheel and gearwheel guards.
Machine tipping over in transport Potential risk to anyone nearby Always lift from top of machine, never under legs
Electrical circuit Risk of electrocution Only trained personnel to work on power circuits

 

 

Risk Items Typical of Power Guillotines

 

Hazard Risk Control Measures
Danger from blades Amputation of operator’s fingers in blades Should only use machine when the finger guard / clamping beam is correctly fitted and adjusted to prevent access to blades.  Daily inspection of condition of safety items is required.
Danger from back gauge Impact from gauge mechanism when machine is cutting Rear of machine should be guarded to prevent access to the blades and the area below the gauge unit
Dropping of shear beam when brake not adjusted correctly Uninitiated stroke Brake adjustment should be checked daily
Clutch key jammed in engaged position Uninitiated stroke Regular inspection by competent person of clutch components to check for wear
Flywheel bush seizing Uninitiated stroke Regular lubrication of plain bush (or upgrade to ball races where possible)
Noise from clamping and work piece Long term hearing damage to operator and others in the vicinity Ear protection should be worn or the machine should be isolated in an enclosure
Repetitive movements in actuating treadle and in moving products Risk to operator Ergonomic layout for parts (consideration of air operated treadle)
Trapping of fingers in rotating parts Risk of partial amputation or spraining of fingers. Machine must be switched off and isolated before removing flywheel and gearwheel guards.
Machine tipping over in transport Potential risk to anyone nearby Always lift from top of machine, never under legs
Electrical circuit Risk of electrocution Only trained personnel to work on power circuits

 

Frequently Asked Questions

Can I put a light beam on my key clutch machine?
You cannot use a light beam guard on a (full revolution) mechanical clutch. Once the mechanical clutch is engaged the guard can’t stop it as the camplate can’t disengage the clutch until it gets back to the lead-in cam face.  Similarly, you cannot use a mechanical interlock on most friction clutch presses, as there is usually nothing accessible on the clutch that you can interlock with.

What is “category 4”? 
Many customers ask if the mechanical guards we supply on our key clutch presses satisfy “category 4”.  This is not a measure of guarding capability, but relates to a requirement for a system of checking and in-built redundancy that is needed for guard components where their operational status cannot be determined by visual inspection.  These guards are typically used on friction clutch presses where a mechanical interlock is not possible.  An electrically interlocked guard can malfunction in a number of situations, such as:- power failure; power surge; broken control wires; short circuited control wires; heavy vibration; contacts welding closed; spring failure in the switch; and the list goes on.  The same applies to pneumatic and to a lesser extent with hydraulic control circuits.

Since you cannot tell if a switch or valve will be capable of working the next time it is used (because you can’t readily see if the contacts have welded or if the spool is jammed) you need to have a system of cross checking in place.  This is normally done using a “safety relay” which is wired directly in to the clutch solenoid valve.

A mechanically interlocked guard can malfunction if one of the components is badly worn or is missing.  To remedy this, a daily inspection of the parts can ascertain if repairs are required or if the guard is safe to use.

Is it safe to put your hands in the die when the guard is open?
The answer to this question is to never regard it as being safe!  Risks may include: the slide falling due to gravity (hence the need for a brake interlock); the slide over-running at the end of the stroke due to brake failure (hence the need for a brake interlock); un-initiated clutch engagement (hence the need for an anti-click eccentric pin under the camplate and a full ring knockout); seizure of the flywheel bush (hence the need for ball race mounting).  To counter most of these risks, John Heine presses since the 1940’s have been fitted with most of these safety devices, but good machine maintenance will also minimise these risks.  If you need to put your hands in the die, it should only be done when the flywheel is stopped and the slide is held up with a solid die chock/block.  Even with these measures in place, there is often jagged material and sharp punches to contend with.

Do I need to spend $20,000 to make my press safe?
Key clutch – A mechanically interlocked die guard is the cheapest option at around $3,500 for a 203A ser 3.  Friction clutch – To get an existing die guard to comply with category 4 (on a press already fitted with a dual solenoid valve) should cost around $5,000.
Why is a full ring knock-out important?    (see also Workcover Victoria Safety Alert)
The main problem with older style knockout cams is that if the brake is poorly adjusted and there is no brake interlock, the press can stop at a point past the end of the knockout cam.  In this position the camplate only needs to move a few millimetres away from the flywheel for the clutch key to be released and stroke the press.  Often this amount of movement can be done even with a die guard interlock bar in place (ie the press strokes with the guard open).  A full ring knockout has additional metal in the bore requiring the camplate to move around 20 mm before engagement can take place.

The secondary problem occurs when a brake interlock is fitted.  The older style knockout allows the camplate shaft to prematurely start moving back to the disengaged position, allowing the interlock bar to rub on the brake drum inner edge.  Prolonged rubbing can wear away the step entirely, leaving nothing to arrest the crank if the slide falls from top centre due to poor brake adjustment or failure.