Vehicle chair having a resiliently supported seat

• US 3,897,036 A
• Filed: 02/05/1973
• Issued: 07/29/1975
• Est. Priority Date: 10/31/1969
• Status: Expired due to Term

• Current Assignee: Karl Gosta Nystrom
• Original Assignee: Karl Gosta Nystrom
• Inventors: Nystrom, Karl Gosta
• Primary Examiner(s): Parsons, Jr., Marion
• Application Number:
  US05/329,951
• Time in Patent Office: 904 Days
• Field of Search: 248/399,400,401,430,421 81/63
• US Class Current: 248/564
• CPC Class Codes: B60N 2/181 Rods
• CPC Class Codes: B60N 2/1842 pivoting about an axis located in the rear
• CPC Class Codes: B60N 2/1885 with weight compensating means
• CPC Class Codes: B60N 2/1892 characterised by a lock
• CPC Class Codes: B60N 2/1896 Stepwise movement mechanisms, e.g. ratchets B60N2/1882 takes precedence
• CPC Class Codes: B60N 2/502 attached to the base of the seat B60N2/504 takes precedence
• CPC Class Codes: B60N 2/505 Adjustable suspension including height adjustment
• CPC Class Codes: B60N 2/507 Parallelogram-like structure
• CPC Class Codes: B60N 2/544 Compression or tension springs B60N2/542 takes precedence

Abstract

A support for a vehicle seat comprising a spring biased linrage pivotally attached to upper and lower structure. The spring biasing means has winding pitch varying along the length of the spring and is adjustable by a ratchet in conjunction with a nut and threaded rod.

Claims

1. A vehicle air comprising in combination:

a. a seat, b. a support structure for the seat, c. at least one pair of parallel supporting arms pivotally connected at one end to the seat and at the other end to the support structure, said arms forming opposite parallelogram links, d. a pivot arm rigidly secured to one of said supporting arms to move in unison therewith, e. spring means interconnecting said pivot arm and said support structure to counteract downward movement of the seat, f. means for varying the attack point of said spring means on the pivot arm to permit an adjustment of the effective length of said arm and, hence, an adjustment of the resultant spring forces acting on the seat, g. said spring means including at least one helical spring having a winding pitch varying along the length thereof so that said spring means will have a progressive spring coefficient, h. said spring means being connected to said pivot arm by a nonrotatable nut mounted on a threaded bolt extending lengthwise of the pivot arm and arranged upon rotation thereof to cause an axial displacement of the nut.

2. A vehicle chair according to claim 1 wherein a toothed wheel is mounted on said bolt and operable for rotation of the bolt in desired direction by means of a cooperating ratchet wrench.

3. A vehicle chair comprising:

a. a support structure, b. a chair seat, c. support arms pivotally connected to said support structure and chair and arranged in a parallelogram mechanism mounting said chair on said support structure, d. a lever arm coupled to the seat so that the angular position thereof will vary in dependence of the vertical movement of the chair seat, e. spring means having a resultant progressively increasing spring coefficient counteracting downward movement of the seat, said spring means comprising a single helical spring having a winding pitch varying continuously along the length thereof, whereby the spring coefficient of said spring will vary continuously in response to changes in the length of the spring, said spring being anchored at one end to said support structure; and

f. means connecting the opposite end of said spring to said lever arm adjustably along said lever arm to permit an adjustment of the resultant spring forces transmitted to the seat, g. said spring means being connected to said lever arm by means of a non-rotatable nut mounted on a threaded bolt extending lengthwise of the lever arm and arranged upon rotation of the bolt to cause an axial displacement of the nut, a toothed wheel mounted on said bolt and ratchet means cooperating with said toothed wheel for rotating the same in a desired direction.