Rotation mechanism for rotatable seat

• US 4,844,543 A
• Filed: 03/10/1988
• Issued: 07/04/1989
• Est. Priority Date: 03/10/1988
• Status: Expired due to Fees

• Current Assignee: Tachi-S Company Limited
• Original Assignee: Tachi-S Company Limited
• Inventors: Ochiai, Susumu
• Primary Examiner(s): Brown, Peter R.
• Application Number:
  US07/166,534
• Time in Patent Office: 481 Days
• Field of Search: 297/344, 297/346, 297/349, 248/416, 248/425, 296/65 R
• US Class Current: 297/344.26
• CPC Class Codes: A47C 3/18 Chairs or stools with rotatable seat adjustable in height by rotation A47C3/24

Abstract

A rotation mechanism for a rotatable seat, in 5 which four rollers are arranged at the seat such that they are disposed equidistant at 90-degree angle from one another, and a substantially isosceles triangle shaped guide member is provided at the floor side of a vehicle such that its vertex extends towards the window-side wall of the vehicle. One of the four rollers is in a rolling contact with the vertex of the guide member when the seat is set in a normal seating position. Thus, with a small rotative force, the seat can be rotated without contact with the windowside wall of the vehicle so as to orient the seat towards a desired seating direction.

Claims

1. A rotation mechanism for a rotatable seat in which said seat includes a seat cushion, an upper frame fixed to the seat cushion, and a lower frame fixed to a floor of a vehicle, said rotation mechanism comprising a slide frame slidably supported on said lower frame in a manner slidingly movable in a direction transversely of a longitudinal centerline of said vehicle, a rotation member rotatably provided on said slide frame, said rotation member being connected to said upper frame, a guide member provided on said lower frame, and a displacing means connected to an underside of said rotation member, said displacing means being movable along said guide member,

wherein, said displacing means comprises four rollers so arranged that they are disposed equidistant at 90-degree angle from one another;

wherein, said guide member is of a substantially isosceles triangle shape, and provided on a lateral section of said lower frame closest to said longitudinal centerline of said vehicle in such a manner that a vertex of said guide member extends inwardly of said lower frame in a direction transversely from said longitudinal centerline of said vehicle; and

wherein one of said four rollers is in a rollable contact with said vertex of said guide member when said seat is set in a position which is parallel or orthogonal with respect to the longitudinal centerline of said vehicle, with said seat cushion being oriented in a seating direction which is parallel or orthogonal with respect to the longitudinal centerline of the vehicle.

2. The rotation mechanism as defined in claim 1, wherein both oblique sides of said guide member are so formed that they diverge from said vertex in a concavely curved manner.

3. The rotation mechanism as defined in claim 2, wherein said guide member has a gently sloped foot portion in each of said oblique sides.

4. The rotation mechanism as defined in claim 1, wherein said guide member is of an isosceles triangle shape, of which both sides are formed rectilinear.

5. The rotation mechanism as defined in claim 1, wherein said guide member has a vertex whose point is formed sharp and wherein said four rollers are each small in diameter.

6. The rotation mechanism as defined in claim 1 further comprising means for maintaining one of said rollers in contact with said vertex of said guide member when the seat is in a position which is parallel or orthogonal to the longitudinal centerline of the vehicle.

7. A rotation mechanism for a rotatable seat in which the seat includes a seat cushion, an upper frame fixed to the seat cushion, and a lower frame fixed to a floor of a vehicle, said rotation mechanism comprising;

a slide frame slidably supported on the lower frame in a manner slidingly movable in a direction transversely of a longitudinal centerline of the vehicle,

a rotation member rotatably provided on the slide frame and connected to the upper frame,

a guide member provided on the lower frame, and

displacing means connected to an underside of said rotation member, said displacing means being movable along said guide member, and said displacing means comprising four rollers so arranged that they are disposed equidistant at a 90-degree angle from one another,

said guide member having a substantially isosceles triangle shape, and provided on a lateral section of the lower frame closest to the longitudinal centerline of the vehicle, said guide member having a vertex extending inwardly of the lower frame in a direction transverse to the longitudinal centerline of the vehicle and two guide surfaces guiding said rollers,

and means for maintaining one of said four rollers in rollable contact with said vertex of said guide member when the seat is set in a position which is parallel with or orthogonal to the longitudinal centerline of the vehicle.

8. The rotation mechanism as defined in claim 7, wherein both guide surfaces of said guide member are so formed that they diverge from said vertex in a concavely curved manner.

9. The rotation mechanism as defined in claim 8, wherein said guide member has a gently sloped foot portion in each of said guide surfaces.

10. The rotation mechanism as defined in claim 7, wherein said guide member is of an isosceles triangle shape, of which both guide surfaces are formed so as to be rectilinear.

11. The rotation mechanism as defined in claim 7, wherein said guide member has a vertex whose point is formed sharp and wherein said four rollers are each small in diameter.