Automatically switching clutch for a motor vehicle exterior mirror adjustment means

Patent metadata

Field	Value
Publication number	US-9470273-B2
Application number	US-201114112592-A
Country	US
Kind code	B2
Filing date	Oct 19, 2011
Priority date	Apr 27, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A clutch device transmits rotational energy between a drive input and a drive output, in particular between an electric actuating unit and an actuating element of an adjustable motor vehicle exterior mirror. The clutch device permits a transmission of a load torque M R from the electric actuating unit to the actuating element in both directions, and in the event of an overload torque greater than a predefined threshold torque M K , automatically permits a relative rotation between the electric actuating unit and the actuating element. Furthermore, the clutch device is designed such that, in the event of a torque direction reversal, no load torque is transmitted over a predetermined free-travel angle (φ).

First claim

The invention claimed is:

1. A clutch device for transmission of a rotational energy between an electric actuating unit and an actuating element, wherein
the clutch device comprises a first clutch part driven by the electric actuating unit, and a second clutch part rotationally fixedly connected to the actuating element, wherein the first or second clutch part comprises a number of rolling elements or a number of sliding elements distributed evenly over its periphery and spring-loaded and pressed against the other one of the first or second clutch parts, wherein said other one of the first and second clutch parts comprises a number of evenly distributed raised portions over its periphery, wherein
the clutch device permits a transmission of a load torque (M R ) from the electric actuating unit to the actuating element in both directions, and in an event of an overload torque greater than a predetermined threshold torque (M K ), in which the raised portions push the rolling elements or sliding elements, automatically permits a relative rotation between the electric actuating unit and the actuating element, wherein
the clutch device, in an event of a torque direction reversal without previous exceeding of the threshold torque (M K ), does not transmit the load torque (M R ) over a predetermined free-travel angle (φ), wherein the free-travel angle (φ) is defined by a distance between two adjacent raised portions.

2. The clutch device according to claim 1 , wherein the free-travel angle (φ) is less than 90°.

3. The clutch device according to claim 1 , wherein
the clutch device comprises a clutch bell or clutch ring, driven by the electric actuating unit as the first clutch part, and a carrier rotationally fixedly connected to the actuating element as the second clutch part, wherein the carrier comprises the rolling elements or the sliding elements distributed evenly over a periphery of the carrier, the rolling elements or sliding elements radially outwardly spring-loaded and pressed against an inner wall of the clutch bell or the clutch ring; and
the inner wall of the clutch bell or the clutch ring comprises the evenly distributed raised portions over its periphery, wherein the raised portions push the rolling elements or the sliding elements in the event of an overload torque greater than the predetermined threshold torque (M K ).

4. The clutch device according to claim 3 , wherein the free-travel angle (φ) is defined by a distance between respectively facing flanks of two adjacent raised portions.

5. The clutch device according to claim 3 , wherein the carrier comprises radially running recesses, the radially running recesses being outwardly opening and evenly distributed over a periphery of the carrier and wherein compression springs that press radial outwardly on the rolling elements or sliding elements are arranged in the recesses, and wherein the rolling elements or sliding elements are guided into the recesses.

6. The clutch device according to claim 5 , wherein a spring constant of the compression springs is chosen such that the rolling elements or sliding elements are pushed sufficiently radially inwardly by the raised portions in order to overcome the raised portions only if the overload torque which is larger than the predetermined threshold torque (M K ) is exerted on the clutch device.

7. The clutch device according to claim 3 , wherein, in order to roll the rolling elements or push the sliding elements on the inner wall of the clutch bell between two raised portions in a circumferential direction, a rolling torque (M W ) of the rolling elements or a frictional torque (M W ) of the sliding elements is smaller than the load torque (M R ).

8. The clutch device according to claim 1 , wherein the number of raised portions is higher than the number of rolling elements or sliding elements.

9. An exterior mirror arrangement for motor vehicles comprising:
a holder mounted on a vehicle;
a housing fixed to the holder;
a holding member for a vehicle exterior mirror displaceably accommodated in the housing; and
a clutch device for a transmission of a rotational energy between an electric actuating unit and an actuating element, wherein the clutch device comprises a first clutch part driven by the electric actuating unit and a second clutch part rotationally fixedly connected to the actuating element, wherein the first or second clutch part comprises rolling elements or sliding elements distributed evenly over its periphery and spring-loaded and pressed against the other one of the first or second clutch parts, wherein said other one of the first or second clutch parts comprises evenly distributed raised portions over its periphery, wherein the clutch device permits a transmission of a load torque (M R ) from the electric actuating unit to the actuating element in both directions, and in an event of an overload torque greater than a predetermined threshold torque (M K ), in which the raised portions push the rolling elements or sliding elements, automatically permits a relative rotation between the electric actuating unit and the actuating element, wherein the clutch device, in an event of a torque direction reversal without previous exceeding of the threshold torque (M K ), does not transmit the load torque (M R ) over a predetermined free-travel angle (φ), wherein the free-travel angle (φ) is defined by a distance between two adjacent raised portions,
wherein the holding member is adjustable via the electric actuating unit and a drive spindle directly or indirectly connected to the holding member, and the clutch device is connected between the electric actuating unit and the drive spindle.

10. The exterior mirror arrangement for motor vehicles according to claim 9 , wherein:
the exterior mirror arrangement further comprises a clamping device comprising a clamping piece loadable against an external wall of the holding member via a cam of a clamping lever pivotably arranged at the housing and which prevents, via a force-fit or frictional fit, a relative movement between the holding member and the housing of the exterior mirror arrangement; and
the electric actuating unit can adjust the holding member even when the holding member is fixedly clamped via the clamping device, wherein the load torque (M R ) necessary for adjusting the holding member and transmittable by the clutch device is greater than a frictional torque (M W ) exerted by the clamping device and is smaller than the predetermined threshold torque (M K ) of the clutch device.

Assignees

• Lang Werner
• Popp Albrecht
• Finkenberger Elmar
• Mekra Lang Gmbh & Co Kg

Inventors

• Lang Werner
• Popp Albrecht
• Finkenberger Elmar

Classifications

• B60R1/078 Primary

  easily removable; mounted for bodily outward movement, e.g. when towing · CPC title

• F16D7/10 Primary

  moving radially between engagement and disengagement · CPC title

• F16D7/00 Primary

  Slip couplings, e.g. slipping on overload, for absorbing shock (combined with yielding shaft couplings F16D3/14; fluid slip couplings F16D31/00 - F16D35/00) · CPC title