Sliding connection

Details Sliding connection Sliding connection

1999-12-23

2001-09-25

Dickson, Paul N. (Department: 3618)

Land vehicles

Wheeled

Running gear

C280S779000, C280S124179

Reexamination Certificate

active

06293573

ABSTRACT:

BACKGROUND OF THE INVENTION
The invention relates to a linear sliding connection between two components which can be displaced back and forth relative to one another, having a damping device effective in at least one of the two axial displacement directions.
In such a sliding connection, the resistance occurring in a first displacement direction is independent of the resistance which appears during a displacement in the opposite direction.
Previously known damping devices include elements such as a spring or a gas-filled chamber, for example. In other configurations, a cylinder filled with fluid is provided through which a piston equipped with a recess can be displaced (or vice versa).
SUMMARY OF THE INVENTION
The invention is based on the object of designing a linear sliding connection with a damping device having the advantages of the previously known configurations, the intention being to create a larger field of application for such sliding connections.
In association with the features quoted at the beginning, this object is achieved in accordance with the invention by a mechanical friction damping device, which has a wire basket acting as a friction and/or clamping element, which wire basket concentrically surrounds the first of the two displaceable components over a longitudinal section so that it is in contact with its outer surface, having one of its axial ends (first basket end) fixed to the second component and having its other axial end (second basket end) supported so that it can be axially and longitudinally displaced on this second component, and is acted upon in the axial direction by an elastic clamping element at this second basket end in such a way that the wire basket has its axial length extended somewhat with simultaneous substantially radial contact pressure against the outer surface of the first component surrounded by it.
In this solution, the damping arises from the clamping force with which the wire basket acts on the component surrounded by it. If the ends of the wire basket are pulled apart, there is a reduction in the basket diameter and, therefore, an increased action on the enclosed component. This axial lengthening of the basket occurs during a relative displacement between the two components. The clamping force produced by this is only released again when a relative displacement takes place between the two components in the opposite direction with the application of a force which exceeds the force of the elastic clamping element.
The maximum clamping force of the wire basket depends, inter alia, on the length and the diameter of the wire basket, the friction coefficient between the wire basket and the enclosed component and the winding angle with which the wire material has been wound in order to form the wire basket.
The solution in accordance with the invention permits a sliding connection which builds up a large displacement resistance, i.e. a high level of damping, in a first displacement direction between two components but practically no damping in the opposite displacement direction. The difference in the damping force for opposite displacement directions can, without difficulty, be in the order of value of a factor of
100
.
A further feature of the sliding connection in accordance with the invention is located in the fact that the displacement resistance is independent of the displacement speed. It is, in addition, advantageous that the sliding connection operates practically without wear. In addition, the desired damping characteristic can be modified in a simple manner by modifying the previously quoted parameters, which determine the maximum clamping force, and by modifying the force of the elastic clamping element.
It is expedient for the section, which is surrounded by the wire basket and is displaceably guided longitudinally in the latter, of the first component to have a circular cross section. This second component can then consist essentially of standardized bar or tube material. The wire basket preferably consists of a wire fabric, by which means a high clamping force can be realized with a wire basket which has a relatively short configuration. The manufacture of wire fabrics is relatively simple.
A simple structure is then ensured if the second component has a cylindrical casing which concentrically surrounds the wire basket. The cylindrical casing then accommodates the entire sliding connection and seals the latter off from the surrounding structure. A simple construction is also ensured when the elastic clamping element has at least one compression spring which concentrically surrounds the wire basket and is supported at one of its ends on the basket end which is supported so that it can be longitudinally displaced axially.
In this arrangement, it is advantageous for a guide element parallel to the axis to be provided for the first component in radial arrangement between the first basket end and the section, which is guided so as to be longitudinally displaceable, of the first component. This provides a particularly stable configuration; the clamping between the components is particularly rigid so that the guide element quoted can also accept fairly large forces which are not applied in the axial direction.
In order to modify the damping characteristic, two compression springs can be provided between the second basket end and the first component. A force/displacement damping characteristic depending on the particular length of the sliding connection can also be achieved by this means.
The sliding connection in accordance with the invention can be advantageously employed as a damping device in a prosthesis or orthesis, where reliability and adjustability of the force/displacement damping characteristic is quite particularly important.
The employment of the sliding connection in accordance with the invention is also advantageous as a damping device in a fitness unit for muscle training. In this case, the sliding connection is used instead of a spring device. In conventional equipment, weights are frequently provided for this purpose which, on the one hand, involve a heavy structure and, on the other hand, normally only permit vertical motions. It is also disadvantageous that potential energy is built up in this arrangement by the raising of the weights and this energy can be abruptly rejected at the end of the exercise. The adjustment of the units operating with weights is, furthermore, time-consuming and labor intensive.
A further modified embodiment in accordance with the invention is characterized by two compression springs, which are arranged one behind the other, whose adjacent spring ends are supported on the second component and whose respective other spring ends are respectively in contact with spring supports which can be displaced axially relative to one another. It is then expedient for the axial displacement of the two spring supports relative to one another to take place manually, for example by actuation of a Bowden cable. In such an embodiment, it is for example expedient for the two components to form a steering column which can be telescopically adjusted longitudinally, one component being provided with a steering wheel and it being possible to fix the other component to a vehicle frame. This configuration can also act as a protective device against the transmission of large forces in the case of an accident or a collision. After a shortening of the steering column, which has taken place because of the action of external force, the original shape can be restored in a simple manner. The clamping force can be reduced or canceled by pressing the two spring supports manually toward one another so that a length adjustment of the steering column is possible to suit the requirement. A torsional restraint between the individual components must also be provided, which is possible by means of a groove/key connection, for example.
Further features of the invention are explained in more detail in association with further advantages of the invention using embodiment examples.


REFERENCES:
patent: 3674283 (1972-07-01),

Affiliated with

Also associated with

Rating

Sliding connection does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Sliding connection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sliding connection will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2474366