Three-sensor fifth wheels

The technology was pioneered by JOST UK 14 years ago. JOST’s Sensoric fifth wheel is based on its market leading lightweight JSK 36D. All the sensors are incorporated within the structure of the fifth wheel, to create a robust and damage resistant unit.

Paul Clayton, JOST’s UK and regional and technical sales and support manager, said: “Safety has to be paramount with fifth wheel couplings. Special features within the standard JSK36D, include a recessed lock jaw to assist safe coupling, guide bars to ensure the king pin is directed squarely into the mechanism, while a fully supported locking bar gives complete security to the king pin when the mechanism is closed. Once the tractor unit and trailer are coupled, an automatic locking catch ensures overall security.

“Thus coupling is quite a straightforward operation and there is even a spring hook and chain to provide extra security. In addition there is also an option of a Fleetmaster handle.”

Uncoupling is equally simple, using the JSK36D’s pull cable.

JOST’s Sensoric fifth wheel brings additional operational safety and driver confidence by detecting three separate functions. The first sensor indicates that the skid plate of the trailer has made contact with the main plate of the fifth wheel; the second one shows that the king pin has entered the mechanism correctly; the third sensor, located on the locking catch, provides a final double check.

When all three sensors have been activated a green ‘coupled’ light is automatically illuminated on the sensor console mounted in the driver’s cab. This confirms to the driver that every step of the coupling process has been safely completed. 

Once driving has commenced the green light gradually fades away until it is completely out. However, the sensors constantly monitor the fifth wheel during travel, giving the driver confidence that the vehicle remains safe.