Elastomer scale

Development of scales for grape harvesting machines

Many wine-growing vineyards don’t use manually operated grape harvest anymore ; it doesn’t respond to quality and production imperatives. The volumes are so sizable that many diversified solutions were imagined, including different  vineyard configurations : high in Italy, low and narrow in Le Mâconnais. Grape harvesting machines have been adapted to all these aeras.

A harvesting machine looks like an unusual tractor : grapevine are shaken thanks to a harvesting head and fruits are gathered in a collecting tray through a conveyor. Articulated arms shake the vines, oscillating hundreds times per minute. Grapes, unhooked by the tremor, fall onto a scales bed connected to the tractor and arranged like a carpet at the level of the vine plant. Thanks to these scales, fruits don’t fall on the ground : they are collected and led to the conveyor. Scales step aside as the vine stock passes and close in a continuous movement despite the repeated shocks, the wear, the friction and mechanical  agressions of such an environment.

The product is reliable and resists to mechanical and dynamic loads, which is essential.

Our customer is specialized in harvesting machines conception and construction  for narrow vines. He gave to Exventys the conception and the realisation of a scale adapted to this configuration. The problem was to realize a flexible articulation and a rigid tray with only one material to avoid the multiplication of the components and assembly stress. Actually, scales are usually made from a rubber articulation fixed to a rigid tray.

A thermoplastic elastomer material was chosen and tested. This kind of material has the particularity to be at once flexible and at the same time to rigidify when its thickness is higher than a certain threshold. The geometry was optimized with a CAD program and some pieces were made directly to be validated with a set of tools used then for the series production. Thanks to the extraordinary resistance of the material and to the expertise of the partner taken for the fabrication, the scales did their job.

Exventys, by bringing expertise and innovation, contributed to the success of its customer who increased the value of its products.