Articulated arm chain hoist: maintenance and inspection
An articulated arm chain hoist combines two assemblies with quite different wear behaviour: a serial hoist that ages by operating hours, and an arm structure that ages by load cycles and moment. Service only the hoist and you miss half of it.
- Rule
- DGUV rule 54 (winches, hoisting and traction equipment)
- Interval
- at least annually
- Makes
- any make
Two joints, one chain hoist, one column – three things that age.
Which rule applies – and at what interval
The chain hoist is hoisting and traction equipment; DGUV rule 54 applies, with inspection by a competent person at least once a year. The actual interval follows from your risk assessment under section 3 of the German Industrial Safety Regulation – with multi-shift operation or a dusty environment it is often shorter. Electrical equipment is inspected additionally under DGUV rule 3. Where the manipulator hangs from a runway, DGUV rule 52 applies to the runway – two rules on one installation, and that is exactly where inspections tend to stay incomplete.
- Rule
- DGUV rule 54 (winches, hoisting and traction equipment)
- Minimum interval
- at least annually
- Inspector
- competent person
What we look at on this unit
| Component | Finding | Discard limit |
|---|---|---|
| Load chain | Pitch elongation, loss of nominal diameter, cracks, corrosion | around 10 % diameter or 5 % elongation – manufacturer data prevails |
| Load hook | Throat opening, deformation, safety latch | 10 % opening against new dimension (DIN 15400) |
| Sprocket & guide | Worn pockets, chain jumping under load | chain jumping always means discard |
| Brake | Lining thickness, holding torque, overtravel | load must hold without creeping |
| Arm joints | Bearing play, worn pins and bushes | noticeable play at the load attachment |
| Column | Anchor bolts, welds, slew ring, cracks in the foundation | any crack, any loose anchor |
The limits come from the applicable rules. Where manufacturer data exists for the specific unit, it prevails.
What actually gets done
Measure the chain, do not look at it
A load chain still looks fine when it is ready for discard. We measure the pitch over several links and the nominal diameter at the most heavily loaded point – usually where the chain runs over the sprocket. Both are recorded so the next visit sees a trend, not just a condition.
Joints and pins
Play in the knuckle joint grows slowly and reaches the operator first as wobble at the load. We check it at the load attachment, not at the joint – that is where the lever acts, and where a tenth of a millimetre of bearing play becomes a centimetre of unsteadiness.
Brake under load
A brake that holds unloaded says little. We test with a load attached: does it hold, does it hold without creeping, and how far does the hoist overtravel when switched off.
Column and anchorage
The most frequently overlooked point of the whole installation. Anchor bolts in the floor are retightened and checked for pull-out, welds at the column base inspected. A manipulator does not tip at the arm, it tips at the foundation.
When the task has changed
Different load attachment
The most common modification and usually the sufficient one: a new gripper, a new beam, a quick-change system for two workpiece families. The unit stays, the task changes.
Renew the control
A contactor control can be replaced by a regulated drive: smooth starting, intermediate positions, usable error messages – without operators having to learn a new machine.
Change the reach
A longer arm is possible but not free: the moment grows, and the limit usually sits in column and foundation. We recalculate the modified condition – and say so when it does not carry.
What we offer for it
Lifting Equipment Maintenance
Planned maintenance of chain hoists, wire rope hoists, balancers and manipulators – any make.
Lifting Equipment Inspection
Recurring inspection under German BetrSichV and DGUV rules – chain hoists, rope hoists, balancers, manipulators and jib cranes.
Repair & Overhaul
Repair of lifting equipment and manipulators of any make – from a brake change to a full overhaul.
Upgrades & Modification
Adapting existing lifting equipment to a new task – gripper, control, reach, capacity.
Questions on maintenance and inspection
Do you service chain hoists that are not yours?
Yes, that is the normal case. A shop that has grown over time holds equipment from several decades and several manufacturers. Where manufacturer documentation exists we work to it; where it is missing we derive the scope from the design and the applicable rules, and write down what it is based on.
How often must an articulated arm chain hoist be inspected?
At least once a year by a competent person. The binding interval is set by you as the operator in the risk assessment – with heavy duty, dust, moisture or a safety-critical task it is shorter. We set it together with you instead of entering a blanket twelve months.
The chain sometimes jumps over the sprocket. Is that serious?
Yes. Chain jumping means chain and sprocket no longer match – usually the chain has elongated, often the sprocket is worn as well. The unit must not be used until repaired; as a rule both parts are replaced, because a new chain on a worn sprocket suffers again immediately.
The unit is over twenty years old. Is it still worth it?
Usually yes. The arm structure and column are long-lived; what ages is the serial hoist. Once its theoretical service life under FEM 9.755 is reached it is overhauled or replaced – the installation as a whole stays. A new unit, by contrast, almost always brings changes to the workstation with it.
Let’s talk about your equipment.
Tell us which units you have – including ones from different manufacturers. We will come back with a proposal for scope and interval.