Carpet weaving technologies

Lancets - a longstanding device now perfected

Lancets, or gauges, are thin metal strips used on face-to-face carpet weaving looms to ensure constant pile height. They are a longstanding device now perfected on ALPHA 500 carpet weaving systems. In combination with the latest Stäubli LX 2493 real three- position Jacquard machine operating on a two rapier loom, especially the unique extra low pile Stäubli lancets, bring important advantages to the carpet weavers.

Readers interested in weaving history will appreciate the following details about the constant evolution of this device.

Lancet on loop-pile loom
Lancets are used on loop pile looms

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.

Lancet compilation FR425646-DE175757
Different ‘lancet’ materials are in use

Before steel that could be rolled into thin metal strips was invented early in the twentieth century, thin metal (piano) wire was used. Other materials, such as cat gut (which continued to be used to string tennis rackets many decades later), were also used. This is mentioned in a patent by Harvey and Harvey of England in 1934. To create higher loops, several wires could be stacked upon each other. A good example of this is shown in the French patent of Paul Girard in 1904. Already in 1904 the use of metal lancets is described in the patent of Wilhelm Förster from Chemnitz, Germany.

Lancet face to face
First lancets in face to face weaving

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 subject to patents in 1928