SPRING-LOADED LEG BASE

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

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.

2. 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.

3. 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.

4. 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.

5. 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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a perspective view of the spring-loaded leg base.

[0021] FIG. 2 is a cross-sectional view of the spring-loaded leg base.

[0022] FIG. 3 is a decomposition (exploded) view of the spring-loaded leg base.

[0023] FIG. 4 is a perspective view of an alternate embodiment of the spring-loaded leg base.

[0024] FIG. 5 is a perspective view of the chair frame.

[0025] FIG. 6 is a side-view of the chair frame.

[0026] Similar reference characters denote corresponding features consistently throughout the attached drawings. Namely, in the drawings the following reference numbers refer to the following part: [0027] 1Base [0028] 11Base bottom [0029] 111Enclosing sleeve [0030] 112Protruding console [0031] 12Cylindrical housing [0032] 121Chamber [0033] 122Grooved track [0034] 123Guiding lips [0035] 2Spring [0036] 3Connecting component [0037] 31Leg sleeve [0038] 32Connecting bar [0039] 33Spring cap [0040] 331Inverted concave cavity [0041] 4Screw [0042] 5Chair frame [0043] 51Horizontal connecting bar [0044] 52Pivot point

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0045] Referring to FIGS. 1-3, a type of spring-loaded leg base is shown including a base 1, a spring 2, and a connecting component 3.

[0046] Base 1 has a chamber with a hollow structure. Specifically, base 1 is a separate structure which includes two parts: a base bottom 11 and a cylindrical housing 12. The perimeter of the base bottom 11 is molded with an enclosing sleeve 111. The center is molded with a protruding console 112. The cylindrical housing 12 is molded with a chamber 121 that has an opening and a grooved track 122. The grooved track 122 is parallel to the central axis of the chamber 121. On the two sides of the grooved track 122, there are guiding lips 123 that protrude outwardly. The lower part of the cylindrical housing 12 is mounted inside the enclosing sleeve 111 of the base bottom 11 and secured by a screw 4 or other fastener. Of course, an alternative option is for the base 11 to be on top, the cylindrical housing 12 at the bottom, and the cylindrical housing 12 to contact the ground. The top is covered with base 11. However, this configuration makes it difficult to produce a conical chamber.

[0047] The spring 2 is placed inside the chamber 121 of the base 1. It can be compressed and expanded along the central axis of the chamber.

[0048] The connecting component 3 has a leg sleeve 31, a connecting bar 32, and a spring cap 33. These three parts together form a one-piece structure. The spring cap 33 is placed inside the chamber of the base 11 and on the top of the spring 2. The connecting bar 32 passes through the grooved track 122. The leg sleeve 31 can be locked in position on the chair frame to create flexible support. With this design, two leg sleeves 31 can be set at an approximately horizontal position and an approximately vertical position, so that they connect with the horizontal end or vertical end of the component at the lower part of the chair frame.

[0049] During installation, the lower part of the spring 2 is set on the protruding console 112 of the base to maintain a centralized structure. After the connecting bar 32 of the connecting component 3 is placed in the grooved track 122 of the cylindrical housing, the cylindrical housing 12 is inverted and tied to the top of the spring 2. The lower part of the cylindrical housing 12 is mounted inside the enclosing sleeve 111 of the base bottom and secured by a screw 4. This forms the spring-loaded leg base unit.

[0050] Furthermore, the aforementioned spring 2 is a conical spring. The chamber of the cylindrical housing 12 is in a corresponding conical structure. Between the mid-upper part of the chamber 121 and the spring 2, there is at least some gap that allows swinging movements of the spring 2. In addition, the spring cap 33 of the connecting bar is molded with an inverted concave cavity 331. This inverted concave cavity 331 is used for buckling onto the top of the spring 2, forming an installation structure. The inherent tension of the spring 2 keeps the spring cap 33 in contact with the top of the chamber 121 and bears the weight of the chair. Another benefit of using a conical spring is that it can create a nested form of compression so that the height after compression can be further lowered, allowing a bigger rocking magnitude under the same condition. The aforementioned spring cap 33 and the chamber 121 maintains a gap that allows reasonable movements of the spring cap 33 without being locked in a fixed position.

[0051] As shown in FIG. 4, the two leg sleeves 31 of the connecting component in this illustration are in an approximately orthogonal position. This is particularly suitable for mounting onto the connecting bar on the rear side of the chair frame.

[0052] Referring to FIG. 5 and FIG. 6, illustrations of the spring-loaded leg base in use. The chair frame 5 has a connecting bar 51 on its rear side. Each of the two spring-loaded leg bases is locked in place on the connecting cross bar 51 by means of a leg sleeve 31. By setting a pivot point 52 at the mid-front area of both sides of the chair frame, the chair can rock back and forth along that pivot point 52. When rocking backward, the spring inside the spring-loaded leg base will be compressed, creating flexible support. Combining the human center of gravity factor and the rebounding force of the spring, the chair can be easily rocked forward. With this, a regular chair may be used to perform rocking function.