Training notes for LIFTMAN^™ pneumatic work platforms (Issue 11, March 2019)

DESIGN PRINCIPLES

The LIFTMAN platform is powered only by compressed air.

This is because:

• compressed air is available in almost all spray booths and prep. areas
• there are no fire, explosion or ignition risks
• by using dry, unlubricated air there is no danger of oil mist contamination.
• components are simple to maintain and to replace if necessary.

The use of compressed air means that the platform is driven by a compressible fluid, and will not have the same positive action as a hydraulic system, however with very little practice you will find that it can be manoeuvred and positioned with great accuracy.

The platform moves on the ground powered by a single drive wheel under the base. It is steered using two wheels and has two further non-steering wheels. The cage also moves vertically up and down the mast to a maximum platform floor height of 2.75 m above ground level. This means a roof of a typical double decker bus can be reached with an average height operator. Driving and steering can be controlled from any platform height but it is not possible to operate lifting and driving at the same time for safety reasons. All controls return to the "off" position when released.

LIFTMAN platforms are ballasted with almost 330 kg of steel in their base unit to make them very stable. It is impossible to overturn them in normal use on level ground. Even by positioning a LIFTMAN close to a solid object, standing in the cage and pushing against the solid object it is only possible to tip them onto two wheels; a normal person’s arms are not long enough to push the platform as far as its point of balance. However there is a two-axis spirit level fixed on the platform base which indicates when the ground surface is not level.

If the cage should be lowered onto an obstacle, the chain could get slack. To avoid this, there is an integrated safety device, which lifts the cage until all chains are taut again.

While this happens, the raising control in the cage is disabled. The same device also prevents further lifting in case of a chain break. Up movement is not possible until the chain is repaired.

LIFTMAN platforms are designed for one operator and his/her equipment only. The safe working load is 140 kg (which is 308 lb or 22 stone) so there are not many operators who would exceed this limit. There is an overload protection device which stops the cage lifting if the rated working load is exceeded by 10%.

The LIFTMAN is supplied by compressed air via a hose reel mounted on the base unit which contains 10 m of hose. This can be supplemented by connecting the hose to the end of a similar hose on a reel mounted on the wall of the booth or work area thereby giving a working radius of the combined lengths of the two hoses.

This air is used for the power supply to the LIFTMAN and also for the operator’s spraygun or other tools. If toxic paints are being used the same air can be filtered locally and used for breathing air. A regulator and pressure gauge is fitted to the platform.

2. CONTROLS

2.1. Up/Down Main Controls

The Up/Down movement of the platform is controlled using the lever positioned on the control panel on the left side of the cage.

Pull the lever up to rise

Push the lever down to descend

For small and accurate movements, operate and release the lever in a series of short actions.

2.2. Left Right Controls

The Left/Right drive is controlled by the foot pedal. Press the right hand side to move right and the left hand side to move left.

It is best practice to press and hold the pedal down rather than “dabbing” at it. The speed is not too fast and positive movements of the pedal will avoid lurching.

The drive is via an air motor mounted in the base of the unit driving the central wheel.

2.3 Steering Control

Steering is controlled by the second lever on the control panel.

Move the lever left to turn left

Move the lever right to turn right

The control moves the steering mechanism and when the lever is released the steering wheels will automatically self-centre.

Remember that the steering wheels are at one end of the LIFTMAN and this may be the “front” or the “back” depending in which direction you are moving at the time.

2.3 Emergency Lowering Valve

There is an Emergency Lowering Valve fitted on the top of the main raising cylinder which can be operated by someone at ground level. This is fitted so that if the operator is incapacitated the cage can be lowered to rescue him/her. This valve will function whether or not the air supply is connected.

2.4 Horn

There is an audible warning device (an air horn) fitted with an operating button on the control panel.

3. SAFETY

The LIFTMAN is designed to be safe, but in common with any mechanical lifting equipment there is the potential for danger if the equipment is misused or used without due care and attention.

3.1 Routine Checks:

Before using the equipment:

• Defects: Check that there are no apparent defects - if there are report them at once.
• Obstructions: Check that there is nothing which will obstruct the movement of the platform, and that the floor area where you intend to operate is reasonably flat and smooth.
• Gate: Check that the gate closes properly - and is closed.
• Air: Check that at least 6 bar of air pressure is available.
• Breathing Air: If you need to use an air fed mask, check breathing air supplies are available.
• Leaks: Check for air leaks. (Listen)
• Controls: Operate the platform in all directions to prove control functions.

3.2 General Safety Instructions:

The Access System is only to be used by authorised personnel who have received the appropriate training.

Do not overload. The safe working load for the platforms is 140 kg (308 lb or 22 stone). This comprises one person plus their equipment. When disconnecting the inlet hose, do not let it retract freely, feed it back into the cassette restraining the spring tension by hand.

Do not use on sloping ground. Use on sloping ground will reduce the stability of the LIFTMAN and could, in extreme circumstances, lead to OVERTURNING! The LIFTMAN should not be used on slopes in excess of 2^O (1 in 30) with anyone in the cage. It is safe to move the LIFTMAN on steeper slopes but only with the cage fully lowered and un-occupied. There is a level (bubble) indicator to determine this.

Do not use on uneven ground. The LIFTMAN will tolerate some unevenness but excessive irregularities may cause it to ground, or the drive wheel to loose traction.

Avoid use with trailing hoses or cables if possible. Compressed air for powering hand tools is provided on the platforms. Using the platforms with hoses or cables trailing from the cage may lead to the platform's movement being restricted, the hoses or cables being run over or subjected to excessive force.

Make sure the LIFTMAN mechanisms are free from any foreign bodies or debris (masking tape, etc.)

Check all around before operating controls. Make sure that the platform is free to move in the desired direction. Check that the cage, the support mast and the platform wheels are all clear of obstruction. Ensure that you know the whereabouts of all other persons working in the area. Beware of people entering the area via personnel doors.

Avoid contact with the vehicle.

Ensure that routine checks are made and that any defects are reported immediately.

3.3. Compressed Air Failure

In the event of air failure (e.g. compressor failure, accidental interruption of supplies or hose damage) the LIFTMAN will not descend in an uncontrolled manner.

If the main air supply fails:

• the cage will stay in its current position
• the steering, driving and up controls will be ineffective
• the down control will function but will provide a reduced rate of descent
• the emergency lowering valve will continue to operate as normal.

The worst case scenario is that if one of the hoses to the main vertical cylinder was ruptured. To our knowledge this has never happened on any of the platforms built. If it did occur the platform would descend at a controlled rate similar to that achieved in normal operation.

4. MOVING THE LIFTMAN WITHOUT AIR CONNECTED

If it is required to move the LIFTMAN when compressed air is not available or beyond the range of the supply hoses, the platform can be easily pushed and steered from the ground using the following procedure:

The driving wheel automatically rises clear of the ground when the air supply is disconnected.

Take the steering tiller from its stowage on the mast and engage it on the square bar projecting from either of the steering wheels.

Lift the brake off the rear wheel using the hand lever

Push or pull the LIFTMAN steering with the tiller.

On completion of the move, reconnect the air supply (which lowers the drive wheel) and replace the tiller in its stowage position. Failure to replace the steering tiller in its correct stowage will inevitably lead to its loss and consequent frustration when you next want to use it!

5. PRACTICAL EXERCISE

5.1 Select a platform and identify the following items:

• Shut-off valve
• Up/Down and Steering Control Levers
• Left/Right Drive Pedal
• Emergency Lowering Valve
• Steering Tiller
• Tool Air Supply, Regulator and Gauge
• Operator Instructions Notice

5.2 Board the platform and go through the safety checks detailed in Sections 3.1 and

3.2 above.

5.3 Having completed the safety checks, operate the controls in turn:

• Raise to full height
• Lower
• Drive Left and Right
• Practice steering while driving in each direction

5.4 Witness demonstration of air failure by training personnel.

6. PERIODIC MAINTENANCE CHECKS AND PROCEDURES

6.1. Daily Procedures

See Section 3.1 above.

6.2 Weekly Procedures

6.2.1 The main lift cylinder piston rod maybe fitted with a fabric protective sleeve. This is to minimise paint spray dust which otherwise may accumulate on the main pneumatic cylinder piston rod. Latest models have special scraper seals which remove the overspray.

6.2.2 Routine inspection and operational checks.

Action:

• Check for air leaks. (Listen)
• Visual check of air hoses for wear and general condition.
• Check access gate operates correctly and the latch engages.
• Check operation of all controls including mast controls.
• Check operation of the brake

6.3. Monthly Procedures

6.3.1 Check all screws, bolts and other fastenings for tightness.

6.3.2 Check support chains for condition and security.

Clean the support chains as necessary and lubricate sparingly.

6.3.3 Check the main lift cylinder piston rod for cleanliness. Raise the platform, disconnect the bottom of the protective sleeve (if fitted) and inspect the piston rod for accumulation of paint residues. Unless removed regularly these may build to sufficient thickness to damage the seals.

If necessary clean the piston rod as follows:

Actions:

• Raise the platform to full height.
• Clean the piston rod with thinners.
• Do not use any abrasive material.
• Lubricate the piston rod sparingly using 10-30 Grade Motor Oil (or equivalent).
• Replace the protective sleeve using a new sleeve if necessary. (Replacing the sleeve requires further dismantling and should only be done in accordance with instructions.)

6.3.4 Main Cylinder Lubrication.

NOTE: Normal operation uses unlubricated air but periodic lubrication is required. Avoid excessive lubrication as this can lead to the release of oil mist into the atmosphere and to damage to the applied paint film.

Action:

• Shut off air supplies.
• Vent the system by operating all control levers in alternate directions. (Finish with platform at bottom position.)
• Remove the air hose at the upper end of the main cylinder and insert two small squirts of oil. Use 10-30 Grade Motor Oil or equivalent. Do not over-lubricate. Replace air hose and check it is secure.
• Turn on the air supply slowly and check for leaks.

6.3.5 Base Unit Procedures:

Raise the platform, remove the base unit cover and fit the steering tiller arm to the square bar projecting from the base of the mast (This acts as a safety stop in case the cage should start to descend).

Remove one air hose from the drive motor (do not operate the Left - Right Control while the hose is disconnected) and insert a couple of drops of oil into the motor connection. Use Pneumatic Tool Oil, 10-30 Grade Motor Oil or equivalent.

Reconnect the air hose and check security.

While the base unit is open, check the tightness of the drive chain (2 - 3 mm movement at the middle of the chain) and adjust as necessary, lubricate the chain sparingly.

Also check the drive wheel tyre pressure (2.0 - 2.5 bar or 29 - 36 psi) and adjust as necessary.

Check and clean the drive motor exhaust as necessary.

Operate the Left - Right Control briefly in each direction and check operation.

Check the Allen Screws which secure the drive motor in its housing.

Check that the steering brake is operating correctly.

Remove the steering tiller, refit the base cover and lower the cage.

6.3.6 Operate all controls to ensure the oil is properly distributed.

6.3.7 If the platform movement is hesitant in the Vertical direction lubricate the vertical mast sparingly with Vaseline or other non-silicone grease.

6.3.8 Pull out the air supply hose from the hose reel and check hose condition with particular attention to the end fixings. If the hose does not retract smoothly apply talc or French chalk to ensure that it is smooth and beds down well on the reel. Adjust the reel tension if necessary. (See hose reel details in Documentation Manual.)

6.3.9 It is recommended that LIFTMAN platforms are inspected and load tested by a competent person at 12 monthly intervals – or more frequently if its use or environment dictates (in accordance with LOLER). Guidance notes for this inspection and a format for a report are included in the Documentation Manual.

7. TROUBLE SHOOTING