Electrically driven device

Patent metadata

Field	Value
Publication number	US-10840767-B2
Application number	US-201715715115-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 28, 2016
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

An electrically driven device includes an electric motor with a drive shaft having a first rotary axis and a drive pin eccentrically thereto, and a driven shaft having a second rotary axis and mounted for pivoting motion. The driven shaft is coupled to the drive shaft by a scotch yoke mechanism, converting a rotary motion of the drive shaft into a reciprocating pivoting motion of the driven shaft. The scotch yoke mechanism includes a cross slider having a sliding support extending perpendicular to the first rotary axis and receiving the drive pin either directly or by a sliding block having a bearing receiving the pin. The cross slider is axially guided to move in an axial direction perpendicular to the first rotary axis and to the extension of the sliding support. The driven shaft is coupled to the cross slider by a pivotable crank arm, thereby converting a rotary motion of the drive shaft into a reciprocating motion of the driven shaft.

First claim

What is claimed is:

1. An electrically driven device comprising
a housing ( 4 ),
an electric motor ( 1 ) mounted in the housing ( 4 ) and comprising a drive shaft ( 2 ) having a first rotary axis (I),
a driven shaft ( 12 ) having a second axis (II) and mounted in the housing ( 4 ) for performing a movement relative to the housing ( 4 ),
wherein the driven shaft ( 12 ) is indirectly coupled to the drive shaft ( 2 ) by a gear mechanism comprising a scotch yoke mechanism ( 5 , 7 ) converting a rotary motion of the drive shaft ( 2 ) into a reciprocating motion of the driven shaft ( 12 ), wherein
a drive pin ( 3 ) is connected to the drive shaft ( 2 ) eccentrically with respect to the rotary axis (I), the scotch yoke mechanism comprises a cross slider ( 7 ) having a sliding support ( 6 ) which extends perpendicular to the first rotary axis (I) and which receives the drive pin ( 3 ) either directly or by a sliding block ( 5 ) having a bearing receiving the drive pin ( 3 ), wherein the cross slider ( 7 ) is axially guided in the housing ( 4 ) to be movable in an axial direction perpendicular to the first rotary axis (I) and perpendicular to the extension (III) of the sliding support ( 6 ), and
the driven shaft ( 12 ) is coupled to the cross slider ( 7 ) by a pivotable crank arm ( 13 ), thereby converting a rotary motion of the drive shaft ( 2 ) into a reciprocating pivoting of the driven shaft ( 12 ),
wherein the cross slider ( 7 ) is displaceably mounted in the housing ( 4 ) by at least two stationary bars ( 8 ) extending perpendicular to the first rotary axis (I) and perpendicular to the extension (III) of the sliding support ( 6 ).

2. The electrically driven device according to claim 1 , wherein the housing ( 4 ) comprises an outer shell ( 10 ) and a chassis ( 9 ) mounted within the outer shell ( 10 ), wherein the at least two stationary bars ( 8 ) are fixed within the chassis ( 9 ).

3. The electrically driven device according to claim 1 , wherein the pivotable crank arm ( 13 ) is pivotably hinged to a bearing point ( 15 ) of the cross slider ( 7 ) and rotationally constrained to an anchorage point of the driven shaft ( 12 ).

4. The electrically driven device according to claim 3 , wherein the crank arm ( 13 ) comprises a bracket with two legs partly receiving the cross slider ( 7 ), wherein the crank arm ( 13 ) is pivotably hinged to the cross slider ( 7 ) by a pin ( 15 ) extending through the cross slider ( 7 ) and at least partly through the legs.

5. The electrically driven device according to claim 3 , wherein the crank arm ( 13 ) comprises a spring flap engaging the housing ( 4 ) or a component part ( 18 ) fixed to the housing ( 4 ).

6. The electrically driven device according to claim 1 , wherein a bar ( 18 ) is provided constrained to the housing ( 4 ) and located at the end of the driven shaft ( 12 ) facing towards the motor ( 1 ).

7. The electrically driven device according to claim 1 , wherein the driven shaft ( 12 ) is pivotably mounted in the housing ( 4 ) by a rocker frame ( 14 ) which is pivotable with respect to the housing ( 4 ) about a pivoting axis (IV) which is perpendicular to the first rotary axis (I) and perpendicular to the extension (III) of the sliding support ( 6 ).

8. The electrically driven device according to claim 7 , wherein an elastically deformable element ( 17 ) is provided between the housing ( 4 ) and the rocker frame ( 14 ) biasing the rocker frame ( 14 ) into a rest position with respect to the housing ( 4 ).

9. The electrically driven device according to claim 7 , wherein a switch or sensor is arranged in the housing ( 4 ) such that the switch or sensor detects movement of the rocker frame ( 14 ) with respect to the housing ( 4 ).

10. The electrically driven device according to claim 7 , wherein the rocker frame ( 14 ) is further guided with respect to the housing ( 4 ) by at least one additional bar ( 15 ) extending parallel to the pivoting axis (IV).

11. The electrically driven device according to claim 7 , wherein movement of the cross slider ( 7 ) generates an intermittent force (F X ) in a direction perpendicular to the axial movement of the cross slider ( 7 ) which intermittent force (F X ) is transmitted to the rocker frame ( 14 ) via the crank arm ( 13 ) and the driven shaft ( 12 ), with the intermittent force (F X ) biasing the rocker frame ( 14 ) away from the rest position.

12. The electrically driven device according to claim 11 , wherein the intermittent force (F X ) generated by the motion of the cross slider ( 7 ) exceeds the biasing force (F V ) of the elastically deformable element ( 17 ).

13. The electrically driven device according to claim 12 , wherein if the rocker frame ( 14 ) is in its rest position with respect to the housing ( 4 ) with the elastically deformable element ( 17 ) being unstressed, a user force exerted on the driven shaft ( 12 ) is directed opposite to the intermittent force (F X ) generated by the motion of the cross slider ( 7 ).

14. The electrically driven device according to claim 1 , wherein the gear mechanism converts a continuous rotary motion of the drive shaft ( 2 ) into a sinusoidal reciprocating displacement of the cross slider ( 7 ).

Assignees

• Braun Gmbh

Inventors

• Fritsch Thomas
• Kramp Andreas
• Schaefer Norbert

Classifications

• A61C17/3472 Primary

  with combined movements of the brush body · CPC title

• A61C17/3418

  Rotation around the axis of the toothbrush handle · CPC title

• A45D2026/008

  Details of apparatus for removing superfluous hair · CPC title

• A61C17/3454

  Translation along the axis perpendicular of the axis of toothbrush handle and in the plane defined by the bristle holder · CPC title

• A61C17/3436

  Rotation around the axis perpendicular to the plane defined by the bristle holder · CPC title