# US 2019/0313797 A1 · Spring-loaded leg base

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- Number: US 2019/0313797 A1
- Document ID: US20190313797A1
- Status: Published application
- Kind: A1
- Application number: 15/950,219
- Filed: 2018-04-11
- Published: 2019-10-17
- Earliest claimed: 2018-04-11
- Assignees: Zenithen USA LLC d/b/a Z Company
- Applicants: Zenithen USA LLC d/b/a Z Company
- Inventors: Andrew David Frankel; Shi-Ping Zheng; Tian-Xia Zheng
- Web page: https://patentgrep.com/patent/US20190313797A1

## CPC

- A47C 3/02: Rocking chairs
- A47C 7/002: {Chair or stool bases (A47C3/20 takes precedence)}
- A47C: CHAIRS; SOFAS; BEDS

## Abstract

A type of spring-loaded leg base includes a base, a spring, and a connecting component. The base has a hollow chamber. The spring is placed inside the chamber. The connecting component is a unified component of a leg sleeve, a connecting bar and a spring cap. By passing the connecting bar through the grooved track and placing the spring cap on the top of the spring, the leg sleeve can be locked in position on the chair frame to create flexible support. This mechanism creates the rocking function for a regular chair.

## Claims

### Claim 1

A spring-loaded leg base comprising:
A base having a hollow chamber inside;
A grooved track installed on the wall of the chamber, wherein the grooved track is parallel to the central axis of the inner chamber;
The spring placed inside the chamber of the base;
A connecting component having a leg sleeve, a connecting bar, and a spring cap forming a one-piece structure, wherein said spring cap is placed inside the chamber of the base and on top of the spring and the connecting bar passes through the grooved track and the leg sleeve can be locked in position on the chair frame to create flexible support.

### Claim 2 (depends on 1)

The spring-loaded leg base of claim 1, wherein the base is a separate structure including a base and a cylindrical housing;
The perimeter of the base bottom is molded with an enclosing sleeve;
The center is molded with a protruding console;
The cylindrical housing is molded with a chamber that has an opening and a grooved track;
The lower part of the spring cap is set on the protruding console to maintain a centralized structure;
After the connecting bar of the connecting component is placed in the grooved track of the cylindrical housing, the cylindrical housing is inverted and tied to the top of the spring; and
The lower part of the cylindrical housing is mounted inside the enclosing sleeve of the base bottom and secured by a screw.

### Claim 3 (depends on 2)

The spring-loaded leg base of claim 2, wherein the spring is a conical spring;
The chamber of the cylindrical housing is in a corresponding conical structure; and
There is a gap between the mid-upper part of the chamber and the spring that allows spring movements.

### Claim 4 (depends on 2)

The spring-loaded leg base of claim 2, wherein the spring cap of the connecting bar is molded with an inverted concave cavity, which is used for buckling at the top of the spring.

### Claim 5 (depends on 2)

The spring-loaded leg base of claim 2, wherein on the cylindrical housing, both sides of the grooved track are equipped with guiding lips that protrude outwardly.