A tour around the factory
A view of what is involved in making Parabolic Springs
Storage of tons of material ready for production. Because the factory wants to keep this stock low it is clear that this is only a small part of the annual production.
First the metal will be cut to the correct length and heated to enable tapering at the right temperature.
This furnace is used to heat the material, one side of each leaf, prior to tapering. A conveyor belt moves the material slowly under the heat source of the furnace to unsure even heating and correct end temperature.
Directly after the leaves come out the furnace they will be tapered, one side each time. This is done by a laminator which will press (while rolling) the tapered thickness, to the parabolic sequence we calculated. It's being extracted from the laminator, center to edge, in two stages.
2 stage tapering sequence
The rolling of the eye will be done after heating the leaf ends in a similar furnace. The end of the leaf will be wrapped around a mandrill which gives the eye the correct diameter, within the specified tolerances.
This is the main furnace to heat the material for final heat treatment. Unlike the other furnaces this furnace will heat the complete leaf, however also in a constant and controlled way, to ensure all stresses will be taken out.
After the heating, the leaf will be placed in the setting and quenching machine, by a robot, where it is clamped into the right camber. Then it is moved slowly into the temperature controlled oil to cool down the leaf and to give it it's spring ability. This part of the production is crucial for a top quality spring. Therefore it is controlled by computer according the ISO 9002 standards, on which the whole production is based.
After cooling down to room temperature, in several carefully controlled stages, the leaves will be stress shot-peened to prolong the life of the spring. The micro cracks, that could be present, will be closed by shooting small particles at high velocity onto the stress surface of the leaf.
Individual leaves are ready for shot peening
The Final assembly of the spring prior to load testing
Load testing sequence is operated by a computer. It will measure camber, force and rate while compressing the spring and letting it rebound, in one dynamic movement, on a special rig. All springs that are conform our specifications will pass this test. The springs that are not conform are rejected and disposed off.
All springs are coated (sprayed) in the well know 'HST Blue' which can be considered a trade mark for top quality parabolic springs.
Although all springs are 'hot stamped' with their part number we still spray this number on the main leaf for identification.
This is only one of the many batches we make and sell during one year.
Efficient production and handling ensure quick and effective dispatch to our customers all over the world.