Lancets - a longstanding device now perfected

Before lancets were introduced on face-to-face looms they had been used on loop-pile looms (Brussels carpets). On loop-pile looms, pile loops are formed over a dummy weft resting on the lancet. Usually the dummy weft is removed afterwards.

When steel quality improved, lancets became suitable for use on face-to-face carpet looms. Using lancets on such looms ensures constant pile height. Without the use of lancets, the pile yarn tends to pull the carpet top and bottom together, giving an uneven pile height. On 3-rapier looms, where lancets cannot be used (the lancet would be in the path of the middle rapier), this is a common problem. It can be worked around by shearing the surface of the carpet, but this leads to a loss of pile height of up to 10%, depending on how much shearing is required. The earliest patent showing the use of lancets on a face-to-face carpet loom is that of Émile Parmentier or Tourcoing in 1904. In practice, this technique did not become common until about 1930.

Lancets made of thin flat steel strips only became common after the First World War. This kind of lancet is used till today. They were used for example by Erkes & Krehbiel of New York in 1932.

This solution – low lancets with the heddles positioned below and above them – is used on the Stäubli ALPHA 500 weaving systems for low pile. With the LX2493 Jacquard machine, weavers can level the pile-yarn heddles in the middle position so that they are above or below the unique Schönherr low lancets. The pile-yarn heddles, except the one in patterning action, are not hindered by the lancets. This solution offers constant pile height plus maximum freedom in weaving (as if without lancets) – for minimum shearing loss and perfectly even surfaces.