Flachfeder

Abstract

Flat spring (1) with a central section (2) arranged between two end sections (3a, 3b); wherein the central section (2) has a wave-like shape extending over or in a plane, and wherein the central section (2) has a flat, planar top (20a) and a flat, planar bottom (20b).

Description

[0001] The present invention relates to a flat spring.

[0002] Various types of springs with different shapes and functions are known on the market.

[0003] Three-dimensional springs are known, such as coil springs, wave springs, leaf springs, clamping springs, band springs, disc springs, and shaped springs. Because these are three-dimensional springs, they obviously present challenges regarding volume, transport, handling, and storage. Furthermore, their three-dimensional shape necessitates a rather complex design when the variables of mechanical strength, elasticity, and elongation need to be modified or adjusted.

[0004] Flat springs with a flat configuration are also known. These are made from a metal rod with a circular cross-section, bent into an essentially sinusoidal wave pattern. This type of flat spring is frequently used in seat cushions.

[0005] Although flat springs can solve the problems related to volume and complexity of your design compared to three-dimensional springs, they have the disadvantage of exerting a low elastic force relative to their volume.

[0006] Springs are also distinguished by their function. Compression springs, extension springs, and torsion springs are well-known. However, these three types of springs differ from one another or, in each case, have different mountings depending on their operating mode.

[0007] In any case, all springs according to the state of the art are affected by design disadvantages resulting from the design and construction of the end sections of the springs or from the fastening methods of the end sections of the springs.

[0008] The object of the present invention is to eliminate the disadvantages of the prior art by providing a flat spring that is compact and easy to store, transport and handle.

[0009] Another task is to provide a flat spring that is versatile and can function under compression, tension or torsion without requiring any changes to its structure.

[0010] Another task is to provide a flat spring that is not limited to the type of end sections and can accommodate all types of attachment to its end sections.

[0011] Another task is to provide such a flat spring that can be easily constructed by modifying its variables in terms of mechanical strength, elasticity, and elongation.

[0012] Another task is to provide a flat spring that is efficient, reliable, and easy to manufacture and assemble.

[0013] This objective is achieved according to the invention by the features of the attached independent claim 1. Advantageous embodiments of the invention are described in the dependent claims.

[0014] Further features of the invention will become clearer from the detailed description below, which refers to a merely exemplary embodiment and therefore does not limit the invention, as illustrated in the accompanying figures. These show: Fig. 1 a top view of a flat spring according to the invention; Fig. 2 an enlarged detail view of Fig. 1, showing a single bend of the flat spring according to the invention; Fig. 3 a cross-sectional view along the section plane III-III of Fig. 2; Fig. 4A-4C three views as in Fig. Figure 1 shows the flat spring according to the invention in tension, compression and torsion operating modes.

[0015] Based on the illustrations, a flat spring according to the invention is described, which is generally designated by reference numeral 1.

[0016] Referring to Fig. 1 The flat spring (1) comprises a middle section (2) which is arranged between two end sections (3a, 3b).

[0017] The middle section (2) has a wave-like shape that extends over or in a plane. The middle section (2) has a flat, planar top (20a) and a flat, planar bottom (20b) ( Fig. 3).

[0018] The middle section includes several bends (20) that are identically designed.

[0019] With reference to the Fig. 2 and Fig. 3 each bend (20) is U-shaped and comprises two straight or rectilinear sections (21) which are connected by a curved section (22) in the form of a semicircle.

[0020] Each straight section (21) has a rectangular cross-section. Similarly, each curved section (22) has a radial rectangular cross-section.

[0021] Each straight section (21) of the bend has a width (W) and a length (L). It should be noted that the width (W) of the straight section extends in the longitudinal direction of the spring, while the length (L) of the straight section extends in the transverse direction of the spring.

[0022] The ratio between the length (L) and the width (W) of the straight or linear section is in the range of 4 to 8.

[0023] The radially measured width (R) of the curved section is constant and corresponds to the width (W) of the straight or linear section.

[0024] Between the two straight or rectilinear sections (21) of a bend there is a distance (D) which corresponds to the width (W) of the straight or rectilinear section.

[0025] Referring to Fig. 1. Each bend (20) has a length (Lo) which is the length of the straight section plus the length (Lr) of any two curved sections. The length (Lr) of each curved section is equal to 1.5 times the width (W) of each curved section, i.e., Lo = L + 3W.

[0026] Each bend (20) has an amplitude or height (A) that is three times the width (W) of each straight or straight section, i.e. A = 3W.

[0027] It should be noted that the length (Lo) of the bend extends in the transverse direction of the spring, while the amplitude or height (A) of the bend extends in the longitudinal direction of the spring.

[0028] The middle section (2), which includes the straight sections (21) and the curved sections (22), has a constant thickness (S).

[0029] The ratio between the width (W) of a straight or straight section and the thickness (S) of the middle section is in the range of 4 to 8.

[0030] As in Fig. As shown in Figure 1, the middle section (2) has the form of a periodic bend with a period (T) that corresponds to four times the width (W) of the straight section, i.e., T = 4W.

[0031] The middle section (2) can include a number of bends (20) in the range of 4 to 14.

[0032] Each end section (3a, 3b) comprises a plate (30) with a central hole (31). The plate (30) has a substantially rectangular or trapezoidal shape with a sloping side (32) that is connected to a curved section (22) of the middle section. In this way, a slot (34a, 34b) is formed between the plate (30) of the end section and the curved section (22) at one end of the middle section.

[0033] As in the Fig. As shown in Figure 1, the slot (34a) in the end section (3a) on the left side is formed between the plate (30) and a maximally curved section (22) of the bend. The slot (34b) in the end section (3a) on the right side, on the other hand, is formed between the plate (30) and a minimally curved section (22) of the bend.

[0034] The plates (30) of the end sections (3a, 3b) have a thickness that corresponds to the thickness (S) of the middle section (2).

[0035] It should be noted that the plate-like shape of the end sections (3a, 3b) makes it possible to easily connect the end sections (3a, 3b) with any type of fastening.

[0036] The spring (1) can be manufactured by cutting a plate from a harmonic or hot-formed spring steel.

[0037] Alternatively, the spring (1) can be made from die-cast harmonic or hot-formed spring steel.

[0038] The plate-like structure of the spring (1) makes it possible to stack the springs on top of each other, with the minimum volume being given by the sum of the thicknesses (S) of the springs.

[0039] Due to the rectangular cross-section of the middle section (2), the new geometry of the spring (1) makes the spring particularly resistant and at the same time elastic.

[0040] With the same dimensions as a conventional flat spring, a flat spring (1) according to the invention has a significantly higher spring force.

[0041] Therefore, if a flat spring (1) with the same spring force as a conventional flat spring is to be manufactured, the flat spring (1) according to the invention will certainly have significantly smaller dimensions.

[0042] There are many variables that affect the strength, elasticity and elongation of the spring (1): - Thickness (S) of the material; - Geometry of the middle section (2) (spring length, spring width, number of bends, amplitude or height of the bend (A), radius of curvature of the curved section (22) etc.); - Type of material; and - Strength of the raw material used.

[0043] In the spring according to the invention, the aforementioned variables can be modified, adapted, or adjusted in various ways.

[0044] Such a flat spring (1) can be used in any way in a tensile, compressive or torsion operation without having to change the structure of the spring.

[0045] Fig. 4A illustrates the use of a flat spring (1) under the influence of a tensile force in the direction of the arrows (F1).

[0046] Fig. Figure 4B illustrates the use of a flat spring (1) under the influence of a compressive force in the direction of the arrows (F2).

[0047] Fig. Figure 4C illustrates the use of a flat spring (1) under the influence of a torsional force in the direction of the arrows (F3).

[0048] In summary, a flat spring (1) comprises a middle section (2) arranged between two end sections (3a, 3b), wherein the middle section (2) has a wave-like shape extending over or in a plane, and the middle section (2) has a flat, planar top (20a) and a flat, planar bottom (20b).

Claims

[1] Flat spring (1) with a central section (2) arranged between two end sections (3a, 3b); wherein the central section (2) has a wave-like shape extending over or in a plane, and wherein the central section (2) has a flat, planar top (20a) and a flat, planar bottom (20b). [2] Flat spring (1) according to claim 1, wherein the middle section (2) of the spring has several bends (20). [3] Flat spring (1) according to claim 2, wherein each bend (20) is U-shaped and comprises two straight or linear sections (21) which are connected to each other by a curved section (22). [4] Flat spring (1) according to claim 3, wherein each straight or linear section (21) of a bend has a rectangular cross-section and each curved section (22) of a bend has a radial rectangular cross-section. [5] Flat spring (1) according to claim 3 or 4, wherein the curved section (22) of each bend is semicircular. [6] Flat spring (1) according to one of claims 2 to 5, wherein the bends (20) are identical. [7] Flat spring (1) according to one of claims 3 to 6, wherein each straight or linear section (21) of a bend has a width (W) and there is a distance (D) between the two straight or linear sections (21) of a bend which corresponds to the width (W) of the straight or linear section. [8] Flat spring (1) according to any one of claims 3 to 6, wherein each straight or rectilinear section (21) of a bend has a width (W), the central section (2) comprising the straight or rectilinear sections (21) and the curved sections (22) has a constant thickness (S) and the ratio between the width (W) of a straight or rectilinear section and the thickness (S) of the central section is in the range of 4 to 8, [9] Flat spring (1) according to any of the preceding claims, wherein each end section (3a, 3b) comprises a plate (30) having the same thickness (S) as the middle section (2). [10] Flat spring (1) according to claim 9, wherein the plate (30) of each end section (3a, 3b) has a hole (31).

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