The motorized roller conveyor: in-line weight checking system

The system consists of:

• 4 FTP 2000 kg shear beam load cells, located under the feet of the roller conveyor;
• 4 PV mounting kits with balls inside the feet and an anti-tilt system;
• 1 TLM8 Profinet IO weight transmitter in an IP69K stainless steel box;
• 4 threaded rods of approximately 50 cm, constrained to the floor and with the two ends constrained to the weighed structure

A motor and a photocell are also mounted on the structure.

A forklift truck rests the pallet on the motorized roller conveyor, which allows the pallet to slide to the point where the photocell is located.

When the pallet passes, the photocell is obscured and stops the system. 
The pallet is thus located in the middle of the structure, right at the exact point where it is going to be weighed.
This is the moment when static weighing takes place and the measured weight is transmitted to the PLC via the Profinet fieldbus.

Once the weight has been recorded, the PLC instructs the system to restart.

With this solution and a few small precautions, the pallet is weighed in complete safety, avoiding potential damage to the weighing system caused by overloading or accidental knocks.

What makes the weighing system so safe and functional?

• The threaded rods, placed horizontally one on each side, which act as a constraint to the structure in all 4 directions and thus protect the load cells from accidental knocks and overloads;
• The TLM8 in a box, which avoids using the junction box for a connection in parallel of the load cells, providing advanced diagnostics
  Installed “in the field”, close to the weighing system, it receives the electrical signal from the load cells and transforms it into the more robust Profinet signal, with which it safely reaches the PLC, even if it is located remotely.
• PV is the safest mounting kit for this type of application: it is equipped with an anti-tilt constraint and its self-centering ball-based system transmits the weight vertically with no lateral friction.
  By always bringing the force back to the middle, it helps the load cell remain constantly accurate and repeatable;
• The PV feet, which make it possible to adjust the height of the accessory so that the structure rests perfectly on all 4 feet with no need to add any other stabilizing elements;
• The pre-sales consulting service for the customer, which is essential so as not to experience any issues in the future.
  Our tips on how to correctly position the constraints against lateral forces to avoid mechanical friction ensure savings in terms of the time and cost of future assistance