TELESCOPIC RAIL

Abstract

The invention concerns a telescopic rail comprising a first rail element with two running surfaces, a second rail element with two running surfaces, at least one rolling body cage for positioning a plurality of rolling bodies. Such telescopic rails are found to suffer from the disadvantage that the rail elements and the rolling body cages all have to be designed to be moveable relative to each other. Accordingly the invention proposes providing a telescopic rail in which the rolling body cage is secured to the first rail element so that the rolling bodies perform a sliding movement with respect to the running surfaces of the first rail element and the rolling bodies perform a sliding movement with respect to the running surfaces of the second rail element or roll on the running surfaces of the second rail element.

Claims

1. A telescopic rail (1) comprising a first rail element (5) with two running surfaces (12, 13), a second rail element (14) with two running surfaces (12, 13), at least one rolling body cage (2) for positioning a plurality of rolling bodies, and a plurality of rolling bodies which are received at the rolling body cage (2), wherein portions (9) of the rolling body cage (2) with the rolling bodies are arranged between the running surfaces (12, 13) of the first (5) and second (14) rail elements in such a way that the first rail element (5) and the second rail element (14) are linearly displaceable relative to each other in an extension direction (15), wherein the rolling body cage (2) establishes a position of each rolling body in the extension direction (15) relative to the rolling body cage (2), characterised in that the rolling body cage (2) is secured to the first rail element (5) so that the rolling bodies perform a sliding movement with respect to the running surfaces (12, 13) of the first rail element (5) and the rolling bodies perform a sliding movement with respect to the running surfaces (12, 13) of the second rail element (14) or roll on the running surfaces (12, 13) of the second rail element (14).

2. A telescopic rail (1) according to claim 1 characterised in that the rolling body cage (2) includes a plastic.

3. A telescopic rail (1) according to claim 1 characterised in that the rolling body cage (2) includes a lubricant.

4. A telescopic rail (1) according to claim 1 characterised in that at least one of the rolling bodies (2) has graphite or at least one of the rolling bodies (2) is made from graphite.

5. A telescopic rail (1) according to claim 1 characterised in that arranged between at least one of the running surfaces (12, 13) of the first rail element (5) and at least one of the running surfaces (12, 13) of the second rail element (14) is a brake body (16) which is secured to the rolling body cage (2) and which upon an extension movement of the first rail element (5) with respect to the second rail element (14) performs a sliding movement on the running surface (12, 13) of the second rail element (14).

6. A telescopic rail (1) according to claim 5 characterised in that the brake body (16) is resiliently prestressed against the running surface (12, 13) of the second rail element (14).

7. A telescopic rail (1) according to claim 5 characterised in that the brake body (16) is in one piece with the rolling body cage (2), the brake body (16) being of a resiliently bendable nature.

8. A telescopic rail (1) according to one of claim 5 characterised in that in a direction perpendicular to the extension direction (15) the brake body (16) has an internal cross-section in the form of part of a circular arc.

9. A telescopic rail (1) according to claim 8 characterised in that arranged between the first rail element (5) and the brake body (16) is a spring element which prestresses the brake body (16) in the direction of the running surface (12, 13) of the second rail element (14).

10. A telescopic rail (1) according to claim 9 characterised in that the spring element is a coil spring (17) having a longitudinal axis, the longitudinal axis extending substantially in the extension direction (15).

11. A telescopic rail (1) according to claim 1 characterised in that the rolling body cage (2) has a projection (8) engaging into an opening (10) in the first rail element (5).

12. A telescopic rail (1) according to claim 1 characterised in that the first rail element (5) is an inner rail and the second rail element (14) is an outer rail.

13. A telescopic rail (1) according to claim 1 characterised in that the rolling bodies (3) are balls.

Description

[0035] Further features, advantages and possible uses of the telescopic rail according to the invention will be apparent from the following description of an embodiment thereof and the accompanying Figures.

[0036] FIG. 1 shows a perspective partially transparent and broken-away view of a telescopic rail according to an embodiment of the present invention,

[0037] FIG. 2 shows a broken-away exploded view of the telescopic rail of FIG. 1, and

[0038] FIG. 3 shows a plan view of the ball cage of the telescopic rail of FIGS. 1 and 2.

[0039] In the Figures identical elements are denoted by identical references.

[0040] FIGS. 1 and 2 show an embodiment of the telescopic rail 1 according to the invention, in which the ball cage 2, besides guiding the rolling bodies in the form of balls 3, also provides four brake elements 4. FIG. 3 shows the ball cage 2 of the telescopic rail 1 of FIGS. 1 and 2.

[0041] In the illustrated embodiment the ball cage 2 is secured to the inner rail 5. Accordingly the inner rail 5 forms the first rail element in accordance with the present application. It can be seen from the exploded view in FIG. 2 that the ball cage 2 is clipped into the inner rail 5 so that it extends between the limbs 6 of the inner rail 5, that carry the running surfaces 12 of the inner rail 5. To prevent displacement of the ball cage 2 with respect to the inner rail 5 the ball cage 2 at its connecting portion 9 has two projections 8 engaging into openings 10 in the inner rail 5, that are complementary to the projections 8.

[0042] The illustrated ball cage 2 is produced in the form of an injection moulding from plastic and thus involves a comparatively low level of friction between the ball cage 2 and the balls 3 accommodated in its through openings.

[0043] The ball cage 2 includes a connecting portion 9 connecting the receiving limbs 11 of the ball cage 2. in the installed state shown in FIG. 1 the receiving limbs 11 then extend between the running surfaces 12, 13 of the inner rail 5 and the outer rail 14.

[0044] By virtue of the ball cage 2 being secured to the inner rail 5 in the extension direction the balls 3 perform a sliding or frictional movement upon extension or relative displacement of the two rail elements 5, 14 at least with respect to the running surfaces 12 of the inner rail 5.

[0045] As in the illustrated embodiment the friction of the balls 3 against the receiving limbs 11 of the ball cage 2 is comparatively low the balls roll on the running surfaces 13 of the outer rail 14. Even if however the rolling movement of the balls 3 on the running surfaces 13 of the outer rail 14 were at least partially replaced by a sliding movement the ball cage 2 of the telescopic rail 1 according to the invention would nonetheless ensure a satisfactory reduction in the friction between the two rail elements 5, 14 during an extension movement.

[0046] The structure of the brake elements 4 can be clearly seen in the plan view of FIG. 3. The brake elements 4 each include a respective brake body 16 which in the mounted state is in frictional engagement with and slides on a running surface 13 of the outer rail 14. The brake body 16 is integrally injection moulded on the rolling body cage 2, more precisely the receiving limbs 11 thereof. In that arrangement the brake body 16 is formed by a resiliently bendable material portion.

[0047] The resiliently bendable material portion is of a part-circular internal cross-section in a plane perpendicular to the extension direction 15. To support the resilient action and prestressing of the brake body 16 which is already provided by the initial material itself a coil spring 17 is disposed in the interior of the cross-sectional profile of the brake body 16.

[0048] In that arrangement the coil spring 17 extends with its longitudinal axis substantially parallel to the extension direction 15. The spring action of the coil spring 17 is utilised in the radial direction and not as is otherwise usual with coil springs in an axial direction. In that way it is possible to set a very clearly defined braking action on the part of the brake body 16 by the choice of a coil spring of suitable radius.

[0049] For the purposes of the original disclosure it is pointed out that all features as can be seen by a man skilled in the art from the present description, the drawings and the claims, even if they are described in specific terms only in connection with certain other features, can be combined both individually and also in any combinations with others of the features or groups of features disclosed here insofar as that has not been expressly excluded or technical aspects make such combinations impossible or meaningless. A comprehensive explicit representation of all conceivable combinations of features is dispensed with here only for the sake of brevity and readability of the description.

[0050] While the invention has been illustrated and described in detail in the drawings and the preceding description that illustration and description is only by way of example and is not deemed to be a limitation on the scope of protection as defined by the claims. The invention is not limited to the disclosed embodiments.

[0051] Modifications in the disclosed embodiments are apparent to the man skilled in the art from the drawings, the description and the accompanying claims. In the claims the word have does not exclude other elements or steps and the indefinite article a does not exclude a plurality. The mere fact that certain features are claimed in different claims does not exclude the combination thereof. References in the claims are not deemed to be a limitation on the scope of protection.

LIST OF REFERENCES

[0052] 1 telescopic rail [0053] 2 ball cage [0054] 3 balls [0055] 4 brake elements [0056] 5 inner rail [0057] 6 limbs [0058] 8 projections [0059] 9 connecting portion [0060] 10 openings [0061] 11 receiving limbs [0062] 12, 13 running surface [0063] 14 outer rail [0064] 15 extension direction [0065] 16 brake body [0066] 17 coil spring