Herringbone pattern

Fish skeleton with bones

natural herringbone pattern

The herringbone pattern (also herringbone pattern or herringbone pattern ) or ear pattern is a pattern or ornament that is based on the arrangement of bones (or backbone with bones) or fruit heads of an ear . It has been known since prehistoric times.

Geometric basics

Its periodically arranged elements usually have a translation symmetry at right angles or 45 ° to the right angle. Topologically , the herringbone pattern is identical to the hexagonal tiling . As a symmetry group it corresponds to the planar crystallographic group pgg .

use

Martin Guitar (HD-28) with herringbone surround of the top

As a woven textile pattern, the herringbone pattern belongs to the twill weave , it is robust but nevertheless with a certain elasticity. In architecture it can be used to connect rectangular individual parts (also parallelograms ), such as paving stones, bricks, tiles, parquet strips - for example, it is used for parquet (see the laying pattern ) or as a masonry bond (see opus spicatum ). The technology is also used in instrument construction, for example for framing the top of high-quality acoustic guitars .

Herringbone pattern in a house wall in Igherm n'Ougdal in the High Atlas

meaning

Herringbone patterns belong in the broadest sense to the net, lattice or zigzag shapes , which have often been assigned a disastrous ( apotropaic ) meaning.

technology

In addition to the pure ornamentation, the pattern also has technical reasons. In all cases, the changing direction of the stroke balances the forces, in the former for elongation, in the latter in the event of shrinkage and swelling of the wood, in the latter for the static load. The forces can be distributed within the association by turning the ridged elements slightly without weakening the association.

There is also the herringbone structure in mechanical use as a herringbone gear pair, for example in gears on steam engines. Similar to a dovetail , the driving force is based on two oppositely inclined gear wheel flanks , thus binding the gear wheel pair to one another without play during the power transmission and avoiding the axial thrust that otherwise occurs with helical gearing. The production is relatively complex and can in principle be made in one or two parts.

The herringbone tread pattern allows climbing in certain circumstances.