Flexible tube with mutually parallel, ring-shaped flutes and axi

Details Flexible tube with mutually parallel, ring-shaped flutes and axi Flexible tube with mutually parallel, ring-shaped flutes and axi

1986-07-15

1988-12-20

Bryant, III, James E.

Pipes and tubular conduits

Combined

With hose protector

138106, 138121, 138172, 138178, 285114, 285226, F16L 2710, F16L 5102

Patent

active

047919639

DESCRIPTION:

BRIEF SUMMARY
The invention relates to a flexible tube with mutually parallel, ring-shaped flutes, end connectors and longitudinal support means which hold said connectors against changes in axial spacing and which are rigidly joined to the connectors in the direction of pull and/or pressure, and against which the tube is at least indirectly braced.
When the term "ring-shaped" is used in this context, it means not necessarily a circular design, but may also refer, for example, to a tube of oval or similar cross-section. As far as the term "holding against a change in axial distance" is concerned, this is not to be understood in the absolute sense, but it allows for unavoidable elasticity, etc., while the longitudinal support means are an attempt to prevent a change in axial spacing as much as possible.


BACKGROUND

Tubes of this type, also referred to as accordion-tubes, are usually made of metal. But depending on the application, other materials, particularly plastic, are possible as well. The tubes normally serve the purpose of providing a flexible link between two medium-carrying parts to which they are connected. When the medium has more than atmospheric pressure, the tube is forced to expand in length, so that it is necessary to use additional means to keep the axial longitudinal spacing of the tube connectors and to brace the tube against buckling or lateral breakout.
For this purpose the tube is provided with steel wire braiding that is rigidly joined to the connectors. Such an external braiding reduces the tube's diameter as it expands longitudinally, but it is unable to do so when it lies closely adjacent to the corrugated tube, and thus it braces the tube connectors against a change in spacing.
However, contact between corrugated tube and braiding leads to considerable friction resulting in tribological stress for both parts, thus significantly reducing the achievable stress reversals under bending load. Essentially this results in wear causing a reduction of the tube's wall thickness, the formation of notches at the tube's outer rims, and a reduction in the braiding wire's diameter; it also results in friction causing a change in the elastic line and the neutral flexural fiber, leading to local overloading.
To limit the above described disadvantages of corrugated tubes with external braiding, numerous attempts have been made to reduce frictional stress effects resulting from interaction between the corrugated tube and braiding. These attempts consisted mainly in using lubricants, in selecting suitable materials with low friction properties, in designing appropriate surfaces in the interaction areas, and in interspersing materials that could be consumed by wear. All these efforts lead to considerable improvements, but they do not provide a life expectancy that under reversed bending stress would even remotely approach the life expectancy of, for example, a corrugated tube without a mantle of braiding.


INVENTION

It is therefore the object of the invention to design a tube of the type mentioned above such that the tribological stress of all component parts is virtually eliminated, i.e. that each part can reach its own full life expectancy without impairment by friction and thus by wear caused by other parts in terms of the stress it has to absorb, especially in terms of reversed bending stress. The means for achieving this goal must not increase the production costs of the tube, on the contrary, they should reduce costs, since additional means previously required to combat wear, such as extra components, material, etc. can be eliminated.
Briefly according to the invention this can be achieved by the longitudinal support being designed as at least one flexible cable that runs largely parallel to the tube. The radial relative position between tube and cable is determined by spacers holding the cable at distances along the length of the tube. The tube is guided in radial direction by the cable.
The term "flexible cable" has been chosen for the sake of simplicity to represent any type of component that would fac

REFERENCES:
patent: 1971928 (1934-08-01), Zallea
patent: 2707117 (1955-04-01), Fentress et al.
patent: 2748803 (1956-06-01), Guarnaschelli
patent: 2894535 (1959-07-01), Hansen
patent: 3006662 (1961-10-01), Katsuhara
patent: 3060972 (1962-10-01), Sheldon
patent: 3162214 (1964-12-01), Bazinet
patent: 3842865 (1974-10-01), Torricelli
patent: 4470433 (1984-09-01), Vipond et al.
patent: 4497342 (1985-02-01), Wenzel et al.
patent: 4686963 (1987-08-01), Cohen et al.

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