A loading mechanism for transferring sling/stillage onto a slow moving buffered area.
We assessed the existing arrangement, hazards and safety. The manufacturer of the new loading mechanism needed to have their design assessed to identify how the hazards may have changed and whether the existing equipment safety checks were adequate in the first place.
The detailed hazard and risk assessment produced included the MRA (Machinery Risk Assessment), RRA (Residual Risk Assessment) all part of the new harmonised risk/safety standard BS EN ISO 12100 (This replaces BS EN 14121-1).
This standard details not only the hazards, but type of risk assessment, as well as the equipment and occupational safety checks.
We apply the same techniques to the new design where the pneumatic transfer method has been replaced by an motorised version.
The system process can now be classified with a new Performance level and measures stated for risk reduction, by means of reduced exposure, additional guarding, zone monitoring, etc.
The main hazards identified in this assessment identified the need for audible warnings due to automatic start-up operations, and the hazards of automatic sling movements in and around the loading area. The need for additional hazard warning signage, floor safety monitoring with the use of floor scanners and more localised emergency stop points. All the hazards were defined and detailed so that the overall performance could be assigned.
S – Severity of injury
S1 Slight (normally reversible) injury
S2 Serious (normally irreversible injury including death)
F – Frequency and/or exposure time to the hazard
F1 Seldom to less often and/or the exposure time is short
F2 Frequent to continuous and/or the exposure time is long
P – Possibility of avoiding the hazard
P1 Possible under specific conditions
P2 Scarcely possible
With a final assessment of all the hazards and risks then the process can be classified using the above table. At ESA we use the popular tool SISTEMA to make sure that all safety related parts of an control system are adequate for the machine/process classification and the MTBF calculations will guarantee correct their safe operation for life cycle of 20 years.
Upgrades, Diagnostics and Process Improvements
Every machine or process at some point in its life cycle will require a change, a modification to suit new tooling or the chemical combination or a change to the method of attaching a sub-assembly and finally, even to speed up the process.
We are able to identify an appropiate solution method and produce an FDS (functional design specification) for any of our projects that require some level of control. In doing so we can apply good manufacturing practices and always ensure quality to our designs and end product.
This upgrade of manual process actioned in nearby station with a Robotic Solution
The client issued an RFQ detailing the requirements for the changes to the station. These included making the station fully automatic with automatic bearing loading, gear meshing and synchro assembly clamp removal.
All these new functions would mean that the automation could be increase the station operation cycle more than 31 seconds.
To achieve all these functions a robot from ABB IRB1600 Robot was selected for the required function with a unique multi-purpose gripper to operate on the following:
- The synchro assembly clamp was required to be removed automatically from the Input shaft assembly and located onto pallet park position.
- The 6th speed gear also was required to be picked up automatically and loaded onto the Input shaft assembly. The gear splines must be mated to the clutch ring splines to ensure the part is located in the home position.
- Automatically pick and load the bearings into the stations press tooling.
- The assembly lines pallet were altered to allow for the placing of the bearing stack for automatic pickup by the robot at this station
- The ability to override the automatic process and return to the manual operation of station was included with the solution as a backup option.
As in every automation project, we were altering the hazards to the existing station, the station had guarding around three side and light guarded access to the front for the operator to load parts and remove unwanted clamps. By adding a robotic solution shown below the whole process had to be risk assessed and new perimeter guarding devised. The new hazard also meant the existing light guard had to be repositioned.
In allowing station to be returned to manual for operator loading, the robot had to be made safe and have its position constantly monitored (parked) by using a series of toothed access point switches.
The automation techniques adopted for this project meant we were able to considerably reduce the cycle time for the station. Through a series of process improvement checks and FMEA studies we devised that a multi-purpose gripper could minimise the need additional tooling and make the process run smoother by reducing the amount of robotic arm movement which in turn kept cycle time to minimum.
Due to profiled guarded area the robot transferred the bearings stack onto separate receptacles on a presenting arm which placed the bearings into magnetic holders for pressing onto the gearing shafts.
Our engineering team has years of experience in tackling varying project sizes covering many different industries. We are able to diagnose faults, suggest improvements for key bottle-neck areas in the production process, as we talk lean manufacturing and are experts in implementing Kaizen and 5S techniques for all types of industry.
…. Ask us on how we can improve or upgrade your machine or process