Vehicle seat

Patent metadata

Field	Value
Publication number	US-9676299-B2
Application number	US-201414334083-A
Country	US
Kind code	B2
Filing date	Jul 17, 2014
Priority date	Jul 19, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Vehicle seat including: a seat back pivoted to a side of floor; a seat cushion pivoted to the seat back; and a front leg element having an upper end pivoted to the seat cushion and a lower end pivotally locked to the side of floor in a releasable manner, thus normally providing a four-pivotal-point linkage in the seat. Maintaining the four-pivotal-point linkage adversely restricts design and actions of the seat. Inequality conditions are therefore set in that four-pivotal-point linkage, such that folding down the seat back by an angle exceeding a predetermined angle results in unlocking of the lower end of the front leg element from the side of floor, thereby destroying the four-pivotal-point linkage. Hence, a freedom of design is increased for the seat and floor. Further, leverage mechanism(s) may be provided to facilitate the ease of unlocking the front leg element from the side of floor.

First claim

What is claimed is:

1. A seat for use with a vehicle having a floor therein, wherein said seat comprises: a seat cushion; and a seat back foldable forwardly and downwardly onto said seat cushion, comprising:
a seat slide device operable for adjustment in position of said seat in forward and rearward directions of the seat, said seat slide device including: a lower rail element fixedly mounted on said floor; and an upper rail element slidably engaged with said lower rail element;
a seat back frame provided in said seat back, said seat back frame being at a lower end thereof pivotally connected to said upper rail element of said seat slide device, thus defining a first pivotal point between said seat back frame and said upper rail element;
a seat cushion frame provided in said seat cushion, said seat cushion frame being at a rearwardly-facing end thereof pivotally connected to said seat back frame, thus defining a second pivotal point between said seat cushion frame and said seat back frame;
a leg element having an upper end pivotally connected to said seat cushion frame, thus defining a third pivotal point between said upper end of said leg element and said seat cushion frame; and
a lock device fixedly disposed at a location substantially corresponding to said upper rail element;
wherein a lower end of said leg element is releasably engaged in said lock device, thereby being normally in a locked relation with said upper rail element of said seat slide device, thus defining a fourth pivotal point between said lower end of said leg element and said upper rail element; and
wherein said first, second, third and fourth pivotal points establish a four-pivotal-point linkage among said seat back frame, said seat cushion frame, said front leg element and said floor,
wherein said four-pivotal-point linkage is normally maintained, and
wherein, when said seat back frame is rotated forwardly and downwardly by a first angle relative to said first pivotal point, a forwardly-facing end portion of said seat cushion frame is brought into contact with said floor, with said lower end portion of said leg element being engaged in said lock device, after which, when said seat back frame is further rotated forwardly and downwardly relative to said first pivotal point by a second angle exceeding a predetermined angle with reference to said first angle, said lower end of said leg element is disengaged from said lock device, thereby destroying said four-pivotal-point linkage.

2. The seat as claimed in claim 1 , wherein said lock device includes an engagement portion defined inside thereof and a resiliently biasing portion, wherein said lower end portion of said front leg element is normally engaged in said engagement portion of said lock device and prevented by said resiliently biasing portion from being removed from said engagement portion, and wherein said lock device is configured such that, when said seat back frame is further rotated forwardly and downwardly relative to said first pivotal point by said second angle exceeding said predetermined angle, the lock device permits said lower end portion of said front leg element to be drawn and disengaged from said engagement portion thereof against a biasing force of said resiliently biasing portion, while permitting said lower end portion to be inserted and engaged in said engagement portion thereof against the biasing force of said resiliently biasing portion.

3. The seat as claimed in claim 1 , which further includes an element with which a lower part of said front leg element near to said fourth pivotal point is to be contacted, thereby limiting movement of said front leg element at said element, wherein said element is provided at or adjacent to said upper rail element of said seat slide device, said element forming a fulcrum, wherein said third pivotal point forms a point of force application, to which a force is to be applied from said seat back frame, wherein said lower end portion of said front leg element forms a point of action against said lock device, whereupon a leverage is provided to said front leg element, and wherein, when said seat back frame is rotated forwardly and downwardly relative to said first pivotal point by said second angle exceeding said predetermined angle, said lower part of said front leg element comes into contact with said element, whereby said force applied from said seat back frame is amplified under said leverage to facilitate disengagement of said lower end portion of said front leg element from said lock device.

4. The seat as claimed in claim 1 , wherein a first distance is set between said first and second pivotal points, wherein a second distance is set between said second and third pivotal points, wherein a third distance is set between said third and fourth pivotal points, wherein a fourth distance is set between said fourth and first pivotal points, and wherein a sum of said first and second distances is not equal to a sum of said third and fourth distances.

5. A seat for use with a vehicle having a floor therein, wherein said seat comprises: a seat cushion; and a seat back foldable forwardly and downwardly onto said seat cushion, comprising:
a seat back frame provided in said seat back, said seat back frame being at a lower end thereof pivotally connected to said floor, thus defining a first pivotal point between said seat back frame and said floor;
a seat cushion frame provided in said seat cushion, said seat cushion frame being at a rearwardly-facing end thereof pivotally connected to said seat back frame, thus defining a second pivotal point between said seat cushion frame and said seat back frame;
a leg element having an upper end pivotally connected to said seat cushion frame, thus defining a third pivotal point between said upper end of said leg element and said seat cushion frame; and
a lock device fixedly disposed at said floor,
wherein a lower end portion of said leg element is releasably engaged in said lock device, thereby being normally in a locked relation with said floor, thus defining a fourth pivotal point between said lower end portion of said leg element and said side of the floor,
wherein said first, second, third and fourth pivotal points establish a four-pivotal-point linkage among said seat back frame, said seat cushion frame, said front leg element and said floor,
wherein said four-pivotal-point linkage is normally maintained, and
wherein, when said seat back frame is rotated forwardly and downwardly by a first angle relative to said first pivotal point, a forwardly-facing end portion of said seat cushion frame is brought into contact with said floor, with said lower end portion of said leg element being engaged in said lock device, after which, when said seat back frame is further rotated forwardly and downwardly relative to said first pivotal point by a second angle exceeding a predetermined angle with reference to said first angle, said lower end of said leg element is disengaged from said lock device, thereby destroying said four-pivotal-point linkage.

6. The seat as claimed in claim 5 , which includes an adjustment device for adjustably positioning said seat in forward and rearward directions of the seat, wherein said adjustment device comprises: a lower rail element fixedly mounted on said floor; and an upper rail element slidably engaged with said lower rail element, wherein said lower end of said seat back frame is pivotally connected to said upper rail element, so that said first pivotal point is defined between said lower end of said seat back frame and said upper rail element.

7. The seat as claimed in claim 5 , wherein said lock device includes an engagement portion defined inside thereof and a resiliently biasing portion, wherein said lower end portion of said front leg el

Assignees

• Tachi S Co

Inventors

• Fukutani Minoru
• Akimoto Norito

Classifications

• B60N2/06 Primary

  slidable (B60N2/12 {, B60N2/2209} take precedence) · CPC title

• B60N2/12 Primary

  slidable and tiltable · CPC title

• B60N2/07

  Slide construction · CPC title

• B60N2/3047

  the cushion being hinged at the back-rest · CPC title

• A47C4/04

  Folding chairs with inflexible seats · CPC title