Step-by-step mechanism

Abstract

A step-by-step mechanism with a housing (2) in which an outer ring (3) and an output element (4) are disposed, the outer ring (3) including double-clamp ramps (6) and the output element (4) including an inner clamping track (7), and, in an annular space (8) formed between the outer ring (3) and the output element (4), clamping bodies (9) being disposed which cooperate with the double-clamp ramps (6), the clamping bodies (8) being spring-loaded. Provided in the housing (2) is a housing-fixed sleeve (10) and spring elements (13) that spring-load the clamping bodies (9) are supported on the sleeve (10).

Claims

1. A step-by-step mechanism comprising a housing, an outer ring and a driven element arranged in the housing, the outer ring has clamp ramps forming a left clamping gap and a right clamping gap, and the driven element has an inner clamping track, clamping bodies arranged in a ring space formed between the outer ring and the driven element, said clamping bodies interact with the clamp ramps and are spring-loaded, a housing-fixed sleeve in the housing, the sleeve including: (a) a base that is elastic in an axial direction, (b) a radially outer portion including a first axial protrusion that surrounds the outer ring, and (c) axial cams positioned radially inwardly from the first axial protrusion that axially project into the ring space, the base extends cantilevered radially inwardly from the axial cams and provides an axial support surface for the driven element, and spring elements that spring-load the clamping bodies are supported against the axial cams.

2. The step-by-step mechanism according to claim 1, wherein the clamping bodies are spring-loaded in a circumferential direction on two sides.

3. The step-by-step mechanism according to claim 1, wherein the driven element is constructed as an inner ring.

4. The step-by-step mechanism according to claim 1, wherein the sleeve is constructed from a plastic.

5. The step-by-step mechanism according to claim 1, wherein the spring elements are compression springs.

6. A seat adjustment device with a step-by-step mechanism according to claim 1, wherein the outer ring is connected to a drive element of a seat adjustment device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment of the invention is described below with reference to three figures. Shown are:

(2) FIG. 1 a longitudinal section through a step-by-step mechanism according to the invention in its rest position,

(3) FIG. 2 a side view of the step-by-step mechanism according to the invention, and

(4) FIG. 3 a longitudinal section through a step-by-step mechanism according to the invention in the adjustment mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) FIGS. 1 to 3 show the step-by-step mechanism 1 according to the invention. The step-by-step mechanism 1 comprises a housing 2 in which an outer ring 3 and a driven element 4 that is formed as an inner ring 5 are arranged.

(6) The outer ring 3 has double clamp ramps 6 that form a left clamping gap 6a and a right clamping gap 6b. The driven element 4 has an inner clamping track 7 and is supported on a bearing pin 11. The outer ring 3 and the driven element 4 form a ring space 8 in which clamping bodies 9 are provided. The clamping bodies 9 interact with the double clamp ramps 6.

(7) In the housing 2 there is a housing-fixed sleeve 10 that is formed from a plastic. The sleeve 10 has cams 12 formed in the axial direction. The cams 12 engage in the ring space 8. Spring elements 13 that spring-load the clamping bodies 9 against the double clamp ramps 6 are supported on the cams. On the cams 12, in the circumferential direction, a spring element 13 is supported in the clockwise direction and a spring element is supported in the counterclockwise direction. This means that the clamping bodies 9 are spring-loaded in the circumferential direction from two sides. The spring elements 13 are formed as compression springs.

(8) In addition, the sleeve 10 has a base 14. The base 14 is elastic in the axial direction and acts on the driven element 4. The base 14 of the sleeve 10 is constructed according to the principle of a plate spring.

(9) Below, the function of the step-by-step mechanism 1 according to the invention is explained with reference to FIGS. 1 and 3.

(10) FIG. 1 shows the step-by-step mechanism 1 in a home position, i.e., the outer ring 3 is not rotating. As can be seen, the clamping bodies 9 are spring-loaded by means of the spring elements 13 against the double clamping ramps 6 such that these are not in contact with the inner clamping track 7. Each spring element 13 acts with the same force on the clamping bodies 9.

(11) FIG. 3 shows the step-by-step mechanism 1 in an adjustment position, i.e., the outer ring 3 is rotating. In the shown embodiment, the outer ring 3 is rotated in the clockwise direction. Consequently, the clamping bodies 9 are pressed by means of the corresponding spring element 13 into the left clamping gap 6a. The clamping bodies 9 are in contact with the outer ring 3 and with the inner clamping track 7 of the driven element 4, wherein the driven element 4 can be carried along. If the outer ring 3 does not rotate, the clamping bodies 9 are moved back into the home position corresponding to FIG. 1.

(12) As an alternative, the outer ring 3 can also rotate in the counterclockwise direction. The clamping bodies 9 are pressed accordingly into the right clamping gap 6b.

(13) Because the base 14 is pressed elastically on the driven element, forward creep of the driven element 4 is prevented.

LIST OF REFERENCE NUMBERS

(14) 1 Step-by-step mechanism 2 Housing 3 Outer ring 4 Driven element 5 Inner ring 6 Double clamp ramps 6a Left clamping gap 6b Right clamping gap 7 Inner clamping track 8 Ring space 9 Clamping bodies 10 Sleeve 11 Bearing pin 12 Cam 13 Spring element 14 Base