Hairpin Bend

Click on a picture to see a larger version.

The 90-degree bend

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Detail shot showing 'overlap' of rollers

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Side-angle, revealing chain drive mechanism

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Smoothed sprocket teeth and side-flex chain.

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A tight squeeze

The requirement was to transfer products through a 90-degree bend. The problem was that the bend was extremely tight.

The available space was so small that even slat conveyors and Plastic Modular conveyors could not be made to produce a tight enough bend.

The application best suited roller conveyors, but we couldn't use these, as the bend was so tight that the rollers would have to physically overlap each other, which is impossible.... or is it ?

The eventual solution was simple, though fiddly to manufacture.

By splitting the roller into disks, with spaces between the disks, then the rollers could - in effect - actually overlap and occupy the same space, whilst still presenting a smooth carrying surface for the product to ride over.

This required considerable precision in the forming of the disks, and of the spacing between them, but the end result was an economical and effective solution.

In most other respects the unit is a straitforwards Chain Driven roller conveyor.

Even here the small radius required some diversions from standard design.

With such a tight bend, the sprockets are noticably out of alignement with their neighbours, and rotated out of true. Under normal circumstances this would cause the chain to distort and possibly spring off the sprocket.

At the same time, the sprocket teeth may 'miss' the chain links on take-up, once more de-railing the chain.

To overcome this the sprocket teeth where individually re-shaped and smoothed to allow the chain to enter them at an angle, whillst still ensuring full take-up. It also required the use of side-flexing chain.