Deceleration device

Patent metadata

Field	Value
Publication number	US-2018149259-A1
Application number	US-201715816358-A
Country	US
Kind code	A1
Filing date	Nov 17, 2017
Priority date	Nov 25, 2016
Publication date	May 31, 2018
Grant date	—

Abstract

A deceleration device for a vehicle seat comprises an external gear comprising teeth with tops projecting radially outward. A tooth of the external gear comprises a straight portion and a critical cross-section located in a dedendum flank of the tooth of the external gear. The straight portion is provided in a vicinity of the critical cross-section and a thickness of the straight portion becomes linearly larger toward a root of the tooth.

First claim

What is claimed is:

1 . A deceleration device for a vehicle seat comprising an external gear comprising teeth with tops projecting radially outward,
wherein a tooth of the external gear comprises:
a straight portion; and
a critical cross-section located in a dedendum flank of the tooth of the external gear,
wherein the straight portion is provided in a vicinity of the critical cross-section, and wherein a thickness of the straight portion becomes linearly larger toward a root of the tooth.

2 . The deceleration device according to claim 1 ,
wherein a centerline of a shape of the tooth that is an imaginary line connects a center point of a top of the tooth and a rotation center of the external gear, and wherein an angle formed by the straight portion and the centerline of the shape of the tooth is smaller than 30 degrees.

3 . The deceleration device according to claim 2 , wherein the angle formed by the straight portion and the centerline of the shape of the tooth is 20 degrees or larger.

4 . The deceleration device according to claim 2 , wherein the angle formed by the straight portion and the centerline of the shape of the tooth is approximately 25 degrees.

5 . A deceleration device for a vehicle seat comprising an external gear comprising teeth with tops projecting radially outward,
wherein a circumference of an imaginary circle overlapping with a surface of a tooth of the external gear and a surface of an adjacent tooth and contacting a bottom land extending between the tooth and the adjacent tooth as a circumference of an osculating circle, and wherein each of the teeth of the external gear comprises a first portion provided in a vicinity of the bottom land and in a dedendum flank of the tooth, the first portion being located toward a top of the tooth relative to the circumference of the osculating circle.

6 . The deceleration device according to claim 1 wherein a surface of the tooth of the external gear is a trochoidal surface.

7 . The deceleration device according to claim 5 wherein a surface of the tooth of the external gear is a trochoidal surface.

8 . A deceleration device for a vehicle seat comprising an external gear comprising teeth with tops projecting radially outward,
wherein a tooth of the external gear comprises a linear surface in a portion of a dedendum flank of the tooth where a thickness of the portion becomes linearly larger toward a root of the tooth, and wherein the linear surface intersects with a critical cross-section of the tooth.

Assignees

• Toyota Boshoku Kk

Inventors

• Ito Sadao

Classifications

• F16H1/32

  in which the central axis of the gearing lies inside the periphery of an orbital gear · CPC title

• B60N2/2252

  in which the central axis of the gearing lies inside the periphery of an orbital gear, e.g. one gear without sun gear · CPC title

• F16H57/08

  of gearings with members having orbital motion · CPC title

• F16H55/0806 Primary

  Involute profile · CPC title

• B60N2/2213

  Gear wheel driven mechanism (B60N2/2231, B60N2/225 take precedence) · CPC title