BASE ASSEMBLY FOR OFFICE CHAIR

Abstract

A base assembly of an office chair includes a mounting member, multiple extensions and a bottom disk. The mounting member has multiple installation slots located evenly along the periphery of the mounting member. Each extension has a connection member at the first end thereof so as to be engaged with the installation slot corresponding thereto. The bottom disk is located at the underside of the first end of each of the extensions and has multiple holes and a central hole. Bolts extend through the holes and are connected to the underside of the mounting member to position the first ends of the extensions.

Description

BACKGROUND OF THE INVENTION

(1) Fields of the Invention

The present invention relates to a base assembly for an office chair, and more particularly, to a base assembly composed of two or three parts.

(2) Descriptions of Related Art

There is a need for most of the users work in the offices to get an office chair which provides proper support to the user and makes the user to be comfortable after being sitting in the chair for whole day. A chair that has poor design and support will cause the user to have muscles sore and pain due to bad blood circulation. A base assembly is a key part for a chair and the star base is commonly used for the chairs. The star base has a larger contact area with the floor and provides better support and balance.

FIG. 1 discloses a conventional base assembly of an office chair and comprises a base 10 with five extensions 11 extending radially from the base 10. The five extensions 11 are evenly separated from each other and each extension 11 has a caster connected thereto. The base 10 has a positioning hole 12 in the center thereof and a support shaft is inserted into the positioning hole 12. The base 10 is integrally formed so as to provide a stable support to the weight of the user. However, the integral base 10 is bulky and occupies a lot of space when packing, storage and transportation.

FIGS. 2 and 3 show the base 20 which is composed of a fixing member 21, a first tube 22 and a second tube 23, wherein the fixing member 21 is a flat board and a connection portion 211 extends centrally from the fixing member 21 so that a support shaft 25 is connected with the connection portion 211. The fixing member 21 has multiple contact portions 212. The first tube 22 is removably connected to the contact portions 212 and the two ends of the first tube 22 contact the floor. The first tube 22 has a first notch 221 defined in the middle portion thereof, and the second tube 23 has a second notch 231 defined in the middle portion thereof. The first and second notches 221, 231 are engaged with each other, and the two ends of the second tube 23 contact the floor. The weight of the user is supported by the fixing member 21 and the first and second tubes 22, 23. The first and second notches 221, 231 weaken the structural strength of the first and second tubes 22, 23, the first and second tubes 22, 23 are easily deformed or broken at the positions wherein the first and second notches 221, 231 are located. The contact portions 212 are connected to the board-like fixing member 21 by bolts 24 so that the contact portions 212 are easily deformed and the bolts 24 can be loosened.

The conventional base of the office chair is a one-piece structure which is solid and strong, but it is also bulky and occupies a lot of space when packing, storage and transportation. Although some of the conventional base assembly is composed of individual parts, the connection is not reliable and is easily broken and deformed, which is not safe.

The present invention intends to provide a base assembly of an office chair which improves the shortcomings mentioned above.

SUMMARY OF THE INVENTION

The present invention relates to a base assembly of an office chair and is composed of two or three parts. The parts occupy not too much space and are easily packed, stored and transported.

The base assembly has a mounting member which is a solid member with threaded holes so that the five extensions are securely connected to the mounting member and are not skew due to weakness of the mounting member.

The openings of the mounting member each are defined by two solid walls which can bear lateral force from the extensions connected to the mounting member. The openings also make the assembling and dis-assembling steps for the base assembly to be simplified.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view to show the conventional integral base assembly;

FIG. 2 is an exploded view of another conventional base assembly;

FIG. 3 is a cross sectional view showing the conventional base assembly in FIG. 2;

FIG. 4 is an exploded view of the first embodiment of the base assembly of the present invention;

FIG. 5 is a perspective view of the first embodiment of the base assembly of the present invention;

FIG. 6 is a cross sectional view of the first embodiment of the base assembly of the present invention;

FIG. 7 is a plan view to show the mounting member of the first embodiment of the base assembly of the present invention;

FIG. 8 is a plan view to show the first embodiment of the base assembly of the present invention;

FIG. 9 is an exploded view of the second embodiment of the base assembly of the present invention;

FIG. 10 is a perspective view of the second embodiment of the base assembly of the present invention;

FIG. 11 is a cross sectional view of the second embodiment of the base assembly of the present invention, and

FIG. 12 is a plan view to show the second embodiment of the base assembly of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 4 to 6, the first embodiment of the base assembly of an office chair of the present invention comprises a mounting member 30, multiple extensions 40 and a bottom disk 50. The mounting member 30 is a cylindrical member and has a positioning hole 31 defined centrally therein, and a shaft 60, such as a gas lift, is inserted in the positioning hole 31. The shaft 60 supports the seat. Multiple installation slots 32 are located evenly along the periphery of the mounting member 30. The installation slots 32 each are a T-shaped hole which has an opening 321 and a curved recess 322. Two sides of each opening 321 are solid walls 323. The underside of the mounting member 10 has multiple threaded holes 324 which are located alternatively relative to the installation slots 32 and defined in the solid material of the mounting member 10. Metal threaded tubes may be inserted into the threaded holes 324.

There are five extensions 40 each have a connection member 41 connected to the first end thereof. The connection member 41 is engaged with the installation slot 32 corresponding thereto. The connection member 41 of each of the extensions 40 is a T-shaped member and has a narrowed neck 411 and a plate 412 extending from two sides of the neck 411. The neck 411 is located corresponding to the opening 321 of the installation slot 32 corresponding thereto. The plate 412 is engaged with the curved recess 322 of the installation slot 32 so as to engage the connection member 41 with the installation slot 32. The second end of each extension 40 is connected with a caster. The five extensions 40 may have different colors.

The bottom disk 50 is a ring-shaped disk and has multiple holes 52 and a central hole 51. Multiple protrusions 53 extend from the bottom disk 50 and are evenly separated from each other, the protrusions 53 are located alternatively relative to the holes 52. Bolts 54 extend through the holes 52 and are connected to the threaded holes 324 in the underside of the mounting member 30 to position the first ends of the extensions 40 as shown in FIG. 6.

When in assembling, the connection members 41 of the extensions 40 are engaged with the installation slots 32 of the mounting member 30, and the necks 411 of the connection members 41 are engaged with the openings 321 of the installation slots 32 and the plates 412 are engaged with the curved recesses 322 of the installation slots 32 to connect the connection members 41 to the installation slots 32. The bottom disk 50 is then positioned at the underside of the first ends of the extensions 40. The protrusions 53 of the bottom disk 50 are engaged with the lower portion of the openings 321 of the installation slots 32. The bolts 54 extend through the holes 52 of the bottom disk 50 and are connected to the threaded holes 324 of the mounting member 30 to secure the bottom disk 50 to the underside of the mounting member 30, and the first ends of the extensions 40 are therefore positioned.

The base assembly are composed of multiple parts, but the threaded holes 324 are located at the solid material of the mounting member 30, and the two sides of each opening 321 are two solid walls 323, so that when the connection members 41 of the extensions 40 are engaged with the installation slots 32 of the mounting member 30, the mounting member 30 bears the upward force from the connection members 41, and the two solid walls 323 of the opening 321 bear the lateral forces from the extensions 40. The five extensions 40 are well balanced and positioned. The bolts 54 are connected to the threaded holes 324 in the solid material can also bear larger forces to prevent the extensions 40 from being loosened or tilt.

There are advantages for the first embodiment described above, the base assembly of the present invention is not a one-piece structure, and composed of multiple small parts which are easily stored, packed and transported, a lot of space is saved. The base assembly is composed of multiple parts but the structural strength is reinforced so that the base assembly does not break. The threaded holes 324 are located in the solid material of the mounting member 30 can bear larger forces from the extensions 40, not any one of the extensions will be tilt and the bolts 54 in the threaded holes 324 do not loose. The two solid walls 323 of the opening 321 bear the lateral forces from the extensions 40. The base assembly is easily assembled and dis-assembled.

FIGS. 9 to 12 show the second embodiment of the present invention, wherein the base assembly of the present invention comprises a mounting member 70, multiple extensions 80, a bottom disk 90 and a cap 100. The mounting member 70 is a cylindrical member and has a positioning hole 71 defined centrally therein, and a shaft 60, such as a gas lift, is inserted in the positioning hole 71. Multiple installation slots 72 are U-shaped slots and located evenly along the periphery of the mounting member 70 as shown in FIG. 12. The installation slots 72 each have an opening 721 and a curved recess 722. Two sides of each opening 721 are solid walls 723. The mounting member 70 has recesses 724 and blocks 725 formed in the inner periphery thereof. Multiple threaded holes 726 are defined in the underside of the mounting member 70 and metal threaded tubes may be installed in the threaded holes 726. The threaded holes 726 of the mounting member 70 are located alternatively relative to the installation slots 72. There are five extensions 80 and each have a connection member 81 connected to the first end thereof, a caster is connected to the second end of each extension 80. The five extensions 80 may have different colors.

A cap 100 is connected to the top of the mounting member 70 and has multiple concavities 101 and insertions 102 on the underside thereof. The blocks 725 are engaged with the concavities 101, and the insertions 102 are engaged with the recesses 724. The connection members 81 of the extensions 80 each have a narrowed neck 811 and a plate 812 extends from two sides of the neck 811. The plates 812 are slightly larger than the connection members 81 and are engaged with the curved recesses 722 of the installation slots 72.

The cap 100 has a passage 104 defined centrally therethrough. The cap 100 has a bottom ring 103 extending from the underside thereof. The bottom disk 90 has a top ring 93 extending from the top thereof, the bottom ring 103 is engaged with notches in respective tops of the necks 811 of the connection members 81 of the extensions 80. The top ring 93 is engaged with notches in respective bottoms of the necks 811 of the connection members 81 of the extensions 80.

The bottom disk 90 is a ring-shaped disk and positioned at the underside of the first ends of the extensions 80. The bottom disk 90 has a central hole 91 and multiple holes 92 in the periphery thereof. Bolts 84 extend through the holes 92 of the bottom disk 90 and are connected to the threaded holes 726 of the mounting member 70 to secure the bottom disk 90 and the extensions 80 to the underside of the mounting member 70.

When in assembling, the connection members 81 of the extensions 80 are engaged with the installation slots 72 of the mounting member 70, and the plates 812 are engaged with the curved recesses 722 of the installation slots 72. The blocks 725 of the mounting member 70 are engaged with the concavities 101 of the cap 100. The insertions 102 are engaged with the recesses 724. The bottom ring 103 is engaged with notches in respective tops of the necks 811 of the connection members 81 of the extensions 80 to position the cap 100 to the top of the mounting member 80, and the bottom disk 90 is connected to the undersides of the connection members 81. The top ring 93 is engaged with notches in respective bottoms of the necks 811 of the connection members 81 of the extensions 80. Bolts 84 extend through the holes 92 of the bottom disk 90 and the threaded holes 726 of the mounting member 70, to secure the bottom disk 90 to the underside of the mounting member 70 and the first ends of the extensions 80.

The base assembly of the second embodiment has five extensions 80 and the five extensions 80 are well balanced and positioned. The bolts 84 are connected to the threaded holes 726 in the solid material can also bear larger forces to prevent the extensions 80 from being loosened or tilt. The bolts 84 do not loose. The use of the cap 100 reinforces the connection of the extensions 80.

There are advantages for the second embodiment described above, the base assembly of the present invention is not a one-piece structure, and composed of multiple small parts which are easily stored, packed and transported, a lot of space is saved. The base assembly is composed of multiple parts but the structural strength is reinforced so that the base assembly does not break. The threaded holes 726 are located in the solid material of the mounting member 70 can bear larger forces from the extensions 80, not any one of the extensions will be tilt and the bolts 84 in the threaded holes 726 do not loose. The two solid walls of the opening 721 bear the lateral forces from the extensions 80. The base assembly is easily assembled and dis-assembled.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.

Claims

1. A base assembly comprising:

a mounting member having multiple installation slots which are located evenly along a periphery of the mounting member, a positioning hole defined centrally in the mounting member and a shaft inserted in the positioning hole;

multiple extensions each having a connection member connected to a first end thereof, the connection member being engaged with the installation slot corresponding thereto, and

a bottom disk located at an underside of the first end of each of the extensions and having multiple holes, bolts extending through the holes and being connected to an underside of the mounting member to position the first ends of the extensions.

2. The base assembly as claimed in claim 1, wherein the underside of the mounting member has multiple threaded holes which are located alternatively relative to the installation slots and defined in a solid material of the mounting member, the installation slots each are a T-shaped hole which has an opening and a curved recess, two sides of each opening are solid walls, the connection member of each of the extensions is a T-shaped member and has a narrowed neck and a plate extending from two sides of the neck, the bottom disk has multiple protrusions which are located alternatively relative to the holes.

3. The base assembly as claimed in claim 1, wherein a cap is connected to a top of the mounting member and has a passage defined centrally therethrough, the cap has multiple concavities and insertions on an underside thereof, the mounting member has multiple threaded holes defined in an underside thereof and the threaded holes of the mounting member are located alternatively relative to the installation slots, each installation slot has an opening and a curved recess, two sides of the opening are solid walls, the mounting member has recesses and blocks formed in an inner periphery thereof, the blocks are engaged with the concavities, the insertions are engaged with the recesses, the connection members of the extensions each have a narrowed neck and a plate extends from two sides of the neck, the plates are larger than the connection members and are engaged with the curved recesses of the installation slots.

4. The base assembly as claimed in claim 3, wherein the cap has a bottom ring extending from the underside thereof, the bottom disk has a top ring extending from a top thereof, the bottom ring is engaged with notches in respective tops of the necks of the connection members of the extensions, the top ring is engaged with notches in respective bottoms of the necks of the connection members of the extensions.