CHAIR CHASSIS

• US 20110193384A1
• Filed: 02/01/2011
• Published: 08/11/2011
• Est. Priority Date: 02/08/2010
• Status: Active Grant

• Current Assignee: Hangzhou Zhongtai Industrial Company Limited
• Original Assignee: Hangzhou Zhongtai Industrial Company Limited
• Inventors: NI, Yong-Xing
• Granted Patent: US 8,613,482 B2
• Time in Patent Office: Days
• US Class Current: 297/311
• CPC Class Codes: A47C 1/026 by means of peg-and-notch or pawl-and-ratchet mechanism

Abstract

A chair chassis is revealed. The chair chassis includes a seat base, a middle base and an adjustment member. A sliding plate is connected to each side of the seat base. A sliding slot is arranged at a front and a rear end of each sliding plate and a pulley is arranged transversely between two sliding slots. The two pulleys connect to a tilting board. The middle base between the two sliding plates connects to the tilting board and the two sliding plates by the pulley on the front end. A third pulley slides over a slant part of the middle base. The adjustment member includes a rack, a locking piece and a lock adjustment rod for control of movement of the locking piece to be engaged with and separated from the rack. Thus users with various weights can use the same chair chassis and operate the chair chassis easier.

Claims

1. A chair chassis comprising:

a seat base whose left and right sides are respectively connected to a sliding plate;

a first sliding slot and a second sliding slot respectively arranged symmetrically at a front end and a rear end of each sliding plate;

a first pulley disposed between and sliding within the two first sliding slots;

a second pulley arranged between and sliding within the two second sliding slots;

the first pulley and the second pulley respectively passed by a tiling board; and

a slant arranged at an edge of the rear end of each sliding plate;

a middle base set between the two sliding plates of the seat base and connected to the tilting board and the two sliding plates by the first pulley;

a slant part on the rear end of the middle base disposed above the slant on the rear end of each sliding plate transversely and a third pulley arranged over the slant part;

two ends of the third pulley respectively fixed on the left and right sides of the seat base and the movable third pulley against the slant part; and

an adjustment member having

a rack set around a middle part of the middle pulley and disposed with a torsion spring on each of two sides thereof;

a locking piece locked with the rack; and

a lock adjustment rod connected to the locking piece for control of forward/backward movement of the locking piece;

wherein when the tilting board moves, the middle base remains still while the first pulley and the second pulley are driven by the pressed tilting board to slide within the first sliding slots and the second sliding slots of the two sliding plates respectively, and the third pulley slides over the slant part of the middle base;

wherein the lock adjustment rod is pulled to drive the locking piece moving forward and backward;

the tilting board is then pressed to drive the rack that moves vertically around the first pulley;

if the locking piece is moved forward, the locking piece is locked with the rack to be in a lock status;

once the locking piece is moved backward, the locking piece is separated from the rack to be in a unlock status.

2. The device as claimed in claim 1, wherein the first pulley includes a shaft and two wheels that are respectively arranged at each of two ends of the shaft.

3. The device as claimed in claim 1, wherein the second pulley includes a shaft and two wheels that are respectively disposed on each of two ends of the shaft.

4. The device as claimed in claim 1, wherein the third pulley includes a shaft and two wheels that are respectively set on each of two ends of the shaft.

5. The device as claimed in claim 1, wherein the first sliding slot on the sliding board is inclined while the second sliding slot is declined.

6. The device as claimed in claim 1, wherein an angle between the slant arranged at the edge of the rear end of the sliding plate and a horizontal plane ranges from 30 degrees to 40 degrees.

7. The device as claimed in claim 1, wherein a diameter of the wheel of the first pulley, a diameter of the wheel of the second pulley and a diameter of the wheel of the third pulley all range from 25 mm to 35 mm.

8. The device as claimed in claim 1, wherein the adjustment member further includes an elastic part;

one end of the elastic part is connected to the lock adjustment rod while the other end thereof is connected to the locking piece.

9. The device as claimed in claim 1, wherein the elastic part is a two-arm torsion spring and an angle between two arms of the two-arm torsion spring ranges from 80 degrees to 120 degrees.

10. The device as claimed in claim 1, wherein an inner side of the slant part of the middle base is further disposed with a partition, a cover plate and a block;

a through hole for the locking piece moving forward/backward therein is mounted on the partition;

the cover plate and the block are respectively arranged above and under the locking piece for receiving the locking piece;

the partition is further fixed with an elastic pad having a concave-convex surface and the lock adjustment rod leans against the concave-convex surface.