US2893724A

US2893724A - Torsion bar construction

Info

Publication number: US2893724A
Application number: US542982A
Authority: US
Inventors: Kales Josef; Grotewohl Albert
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 1954-10-30
Filing date: 1955-10-26
Publication date: 1959-07-07
Anticipated expiration: 1976-07-07

Description

y 19359 J. KALES EIAL 2,893,724

TORSION BAR CONSTRUCTION Filed Oct. 26. 1955 I z.

u M Ma 1M. k P E m DIPL.-IAIG. ALBEKT cmzz'wouL BY j 5 MITH, 01 suv'd K0 m A TTORNEYS United States Patent TORSION BAR CONSTRUCTION Josef Kales and 'Albert Grotewohl, Wolfsburg, Niedersachsen, Germany, assignors to Volkswagenwerh G.m.b.H., Wolfsburg, Germany Application October 26, 1955, Serial No. 542,982 1 Claim. (Cl. 267-57) This invention concerns torsion bars.

When a group of spring torsion bars consisting of layered spring leaves is twisted, the outer leaves also require bending in addition to twisting. If in this case all the leaves, as is cutomary, are of equal width and are arranged in a receiving member of rectangular crosssection, the outer leaves additionally experience strong local compressions due to the setting up of the twisting moment in the fixed end. Fractures which occur therefore begin exclusively from the point of support of the outer leaves. The loading capacity of the whole group is consequently limited by the danger of overloading the outer leaves at the fixed end, while the inner layers are not fully utilized.

According to the present invention, in a torsion bar assembly consisting of layered spring leaves, particularly for mechanically propelled vehicles, the leaves superimposed upon one another are of varying width, decreasing from the centre of the assembly outwards in such a way that said assembly is adapted to be received in a bush of circular cross-section.

By means of the varying width of the leaves, an approximately uniform utilization of every individual rectangular bar can be achieved. Bearing in mind that in all the bars the individual maximum loads are to be as far as possible approximately equal to one another, it may be found convenient also to vary the thickness of the bars in addition to varying their widths. The most favorable dimensioning of the individual thicknesses will be calculated for each specific case. In general, a variation of thickness decreasing from the inner to the outer bars will be the one employed, although other arrangements are also possible, e.g. that in which the innermost bars are made the thickest, the outermost bars less thick, and the intermediate bars the thinnest.

The possibility also exists of so dimensioning the outermost bars in width and/or thickness that they are loaded to a somewhat lesser degree than the remaining bars situated between them. A fracture then possibly occurring would thus in all likelihood appear only on one of the intermediate bars. The advantage as compared with a group of bars of the same thickness and width throughout, with fractures taking place only in the outside leaves, is that the effective volume of the spring assembly is scarcely reduced, since a broken intermediate leaf is almost completely turned jointly by the two neighboring leaves.

A further advantage of the invention is that, compared with a group of bars of equal width, it gives a better utilization of the circumscribed circle, and thus a receiving member of smaller size may be employed, and, in the case of a mechanically propelled vehicle, a lighter supporting arm. If the receiving member is also toothed internally, then in place of a concentration of the local compressions resulting from the twisting moment in the two outside bars, a distribution of the pressures over several or all of the bars takes place.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

Fig. l is an end elevation of a group of spring bars constructed in accordance with the invention, and

Fig. 2 is an end elevation, partly in section, of a torsion bar and supporting arm assembly constructed in accordance with the invention.

The torsion bar assembly shown in Fig. 1 consists of eight single bars 1 of diflierent width and thickness from one another, and presenting a total cross-section which almost completely occupies the imaginary circumscribed circle 2.

In the embodiment shown in Fig. 2, a supporting arm 3 is formed at one end with an internal toothed bore 6. Bore 6 provides teeth 7 which receive a torsion bar assembly comprising nine bars or leaves 1 varying both in thickness (in the arrow 8 direction) and in width (in the arrow 9 direction). It will be noted that the torsion bar assembly is of generally stepped configuration so as to expose the lateral areas of individual bars, the arrangement being such that the teeth formed by bar 6 engage said lateral areas of the leaves to rigidly anchor the lever arm 3 and individual ones of the leaves together. The bars 1 are retained in the supporting area 3 against axial displacement by means of a screw 4 and locknut 5.

We claim:

A torsion bar assembly comprising a plurality of flat layered spring leaves; adjacent ones of said leaves varying substantially in width from one another, with the leaf width decreasing from the center of the assembly outwardly to provide a stepped configuration; a lever arm having a bore conforming to the stepped configuration of the spring leaves and engaging the exposed lateral areas of the flat leaf surfaces to rigidly anchor the lever arm and adjacent portions of the spring leaves together; the individual leaves being of dilferent thickness, decreasing generally from the inner to the outer leaves.

References Cited in the file of this patent UNITED STATES PATENTS 2,194,964 Willson Mar. 26, 1940 2,778,626 Klepp Jan. 22, 1957 FOREIGN PATENTS 20,027 Austria May 10, 1905 146,568 Great Britain June 18, 1920 632,998 Great Britain Dec. 5, 1949 962,3 82 France Dec. 12, 1949