A composite coil spring includes a coil body that has a core and fiber layers impregnated with a polymer material. The fiber layers are wound around the core. The fiber layers extend around the coiled axis at oblique fiber angles. Each of the fiber layers includes a number of fibers that is a product of a common base number of fibers multiplied by a positive non-zero integer from a set of positive non-zero integers from 1 to 20. The positive non-zero integer of at least one of the fiber layers is different from the positive non-zero integer of at least one other of the fiber layers. At least one of the fibers layers is glass fibers and another of the fiber layers is carbon fibers, and each of an innermost fiber layer and an outmost fiber layer of the fiber layers is independently selected from glass fibers and carbon fibers.

A composite coil spring (20) includes a coil body (2) that extends along a coiled axis (24). The coil body includes a core (38) and a plurality of fiber layers (32) impregnated with a polymer material. The plurality of fiber layers are arranged around the core at different radial distances from the coiled axis. Each of the plurality of fiber layers extends around the coiled axis at an oblique fiber angle to the coiled axis. Each of the plurality of fiber layers includes a number of fibers that is a product of a common base number of fibers multiplied by a positive non-zero integer from a set of positive non-zero integers. The positive non-zero integer of at least one of the plurality of fiber layers is different from the positive non-zero integer of at least one other of the plurality of fiber layers.

A torsion spring may be configured as a torsion bar or a helical spring made of a spring wire made of fiber-composite material. The torsion spring may have a plurality of layers of fiber reinforcement that have been saturated with a matrix material, wherein the layers may have fibers that are tension-loaded and fibers that are compression-loaded. The at least one compression-loaded group may have a lower group stiffness than the tension-loaded group with the highest group stiffness. Methods for designing or making torsion springs made of fiber-composite material are also disclosed.

A spring made of a fiber composite includes a metal thread which is connected to the spring and has an electrical resistance which changes in dependence on a deformation of the spring. The metal thread can be integrated inside the spring or may also be arranged on an outer side of the spring.

A compression spring is disclosed, which is configured to be used for various applications, and in particular for operate accessory linkages. Furthermore, a compression spring retention system is disclosed including a compression spring and a housing in which the compression spring is fixable. The compression spring includes a length of coiled wire having substantially a circular cross-sectional area, wherein at least a first end of the compression spring is formed as a retainer device that is configured to be compressed while being mounted into a recessed chamber of the housing and to expand when inserted into the recessed chamber in a way that the compression spring is fixed at the recessed chamber.

A torsion spring may be formed as a bar spring or helical spring comprising a spring wire of fiber composite material. In some examples, the torsion spring comprises a number of layers of fiber reinforcement, which are impregnated with a matrix material. The layers may comprise tensile-loaded fibers and compression-loaded fibers. Groups of layers of the same loading direction may exist and, seen from an inside to an outside, the group stiffness of at least two groups may differ. Likewise, methods for making such torsion springs of fiber composite material are disclosed.

The invention relates to a torsion carrier, particularly a torsion spring, helical spring, drive shaft or balance shaft, which enables significant material and installation space savings compared to the prior art. The torsion carrier consists of a plurality of, but at least two supporting layers lying radially one above the other, each of which consists of at least one spiral coil (1, 3), but preferably of a plurality of spiral coils made of predominantly unidirectional composite fiber material, wherein at least two of the supporting layers have a counterrotating spiral coil orientation relative to one other. An elastic intermediate spacer layer (2) is arranged between adjacent spiral coil layers, by means of which a decoupling of the spiral coil expansions of adjacent spiral coil layers is achieved. This achieves particularly favorable, predominantly single-axis states of stress which allow for a high level of material utilization.

A composite coil spring includes a coil body that extends along a coiled axis. The coil body includes a polymer matrix and, disposed in the polymer matrix, a carbon fiber core and a plurality of fiber layers wrapped around the carbon fiber core in alternating oblique fiber angles to the coiled axis. The fiber layers include, from inside-out starting from the carbon fiber core, at least two consecutive carbon fiber intermediate fiber layers of alternating oblique fiber angles to the coiled axis, immediately followed by at least two consecutive glass fiber intermediate fiber layers of alternating oblique fiber angles to the coiled axis, and immediately followed by a carbon fiber outermost fiber layer.