CA2186291A1

CA2186291A1 - Office chair base without castors

Info

Publication number: CA2186291A1
Application number: CA002186291A
Authority: CA
Inventors: Peter Gueorgiev Demerdjiev; Penka Dimitrova Demerdjiev
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-10-07
Filing date: 1996-10-07
Publication date: 1998-04-07

Abstract

All office chairs have to ensure fast and smooth horizontal movement in all directions. This problem has so far been resolved with the use of castors as part of the architecture of the chair base. In this invention the castors are eliminated and replaced by a freely rotating, centrally located ball and supporting legs with rotating tips. This is an entirely new approach to resolving the problem and a new aesthetic concept. This invention also secures independent rotation of the top and bottom parts of the chair base.

Description

SPECIFICATION:
The invention relates to an office chair base without castors.
Cull~nlly all bases use castors as a separate structural element. They vary in size and form, but inevitably form part of the office chair architecture. It is the only element that has not been radically redesigned and has become a serious aesthetic handicap. The castors are usually made of plastic, break fairly easily, require a lot of effort for the initial push to put the system into motion, particularly on carpeted surfaces and normally pieces of adhesive matter(letter mail labels, stickers, scotch tape pieces, etc.)get stuck to them and get inside the grooves which eventually blocks the movement. Allen~t~ in this direction have been made in thepast, as we can see in U.S. patents 4,998,699 and 3,528,635, which do not go beyond improving the shape and function of the castors. In another U.S. design patent allempl has been made to create a new type of office chair base with better aesthetics and increased maneuverability by decreasing the number of supporting legs to three, but increasing the number of castors to a total of six, coupled in pairs for each supporting leg.
I found out that by elimin~ting the castors and replacing them with a freely rotating, centrally located ball and rotating tips of the supporting legs, all of the above mentioned problems will be elimin~ted This office chair base will provide designers with new aesthetic possibilities for expression and will result in a smoother and better operation.
BRIEF DESCRIPTION OF THE DRAWINGS:
In drawings, which illustrate embodiments of the invention, Figure l(scale 1:4)isanelevationoftheembodiment.
Figure 2(scale 1 :4)is a top view of the embo-liment Figure 3(scale 1: l)is a detail cross-section of line A-A on Fig.2 Figure 4(scale 1: l)is a detail cross-section of line A-A on Fig.2(contimled) Figure 5(scale 1: l)is a side view of Fig.4 Figure 6(scale 1: l)is a detail cross-section of line B-B on Fig.3.
Figure 7(scale 1: l)is a detail cross- section of line C-C on Fig.3.
Figure 8 is a perspective cross section view.
DEI'AILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
The illustrated office chair base consists of two groups of elements with own independent movement, connected together and forming one integral body.
The first group is formed of central element 4; freely rotating ball 1; roll bearing 2, embedded in central unit 4; supporting legs 5 with rotating tips 15;
magnet 7, fixed into position to central element 4 with a screw 8. The magnet 7 2186~91 keeps ball 1 into position, if the chair is lifted up in the air; protective ring 5, fixed to central element 4; cleaning filter ring 3, glued to protective ring 5; protective cap 12, screwed to central element 4.
The second group consists of top freely rotating part 9; roll bearing 10, embedded in top freely rotating part 9; loose protective ring 11.
The first group, as listed in the above paragraph, enables smooth and fast movement of the whole construction, respectively the office chair in any desiredhorizontal direction. The movement is initiated by the freely rotating ball 1, transmitted to roll bearing 2 and through central element 4 and supporting legs 6 to the rotating tips 15. The movement of freely rotating ball 1 in any direction will cause roll bearing 2 and the supporting leg tips 15 to set into a circular motion around the vertical axis of symmetry the first group, as described above. The circular motion could be clockwise or anticlockwise.
Rotating tip 15 of supporting leg 6, as illustrated in Fig.4, consists of a rollbearing 14, embedded in central axial element 17; ring 16, which keeps rotating tip 15 into position and at the same time allows its free rotation around central axial element 17 and is fixed to rotating tip 15 with screws 13; central axial element 17 is fixed to supporting leg 6 also with screws 13; protective cap 18 prevents dust and other foreign matter from entering the inside of rotating tip 15.
Top freely rotating part 9, to which the vertical supporting column of the office chair will be fixed, as illustrated in Fig.3, Fig.7, at the same time preserves its independent range of movement and could remain still, rotate in the same or opposite direction to the rotation of the first group, as listed above, depending on the wish of the person using the chair. The movement of the top freely rotating part 9 is effectuated by a roll bearing 10, embedded in 9 and ~ ate~l in a groove, formed by central element 4 and top freely rotating part 9; loose protective ring 11, ensures movement without vibrations and keeps top freely rotating part 9 into horizontal position; protective cap 12 is fixed with a screw to central element 4, covers the groove, roll bearing 10, protective ring 11 and keeps top freely rotating part 9 into position if the chair is lifted up in the air.
MATERIALS USED FOR THE ELEMENTS OF THE CHAIR BASE:

freely rotating ball l-hollow stainless steel ball with thin rubber coating;
roll bearing 2-stainless steel; filter ring 3-wad(ling; central element 4-metal or plastic cast, in case of plastic cast, metal anchors have to be secured for the screw of protective cap 12 and for screw 8; protective ring 5-painted stainless steel;

218~91 3 r supporting legs 6-painted stainless steel tube or a plastic cast, in which case is possible supporting legs 6 and central element 4 to be made both of plastic and according to the desire of the manufacturer to form one single cast; magnet 7-metal cast; screw 8-metal; top freely rotating part 9-painted stainless steel; roll bearing 10-stainless steel; loose protective ring 11-durable plastic; protective cap 12-painted stainless steel; screws 13-metal; roll bearing 14-stainless steel;
rotating tips 15-painted stainless steel; ring 16-durable plastic; central axialelement 17-stainless steel; protective ring 18-durable plastic.
The top freely rotating part 9, as illustrated in the drawings, could accommodate vertical supporting columns of office chairs with diameter up to 60 rnillimeters, but if necessaIy larger diameters could be accommodated by increasing the diameter of top freely rotating part 9.

Claims

1. An office chair base without castors, consisting of a freely rotating, centrally located ball, supporting legs with rotating tips and a top freely rotating part.

2. An office chair base as defined in claim 1, the top and bottom part of which have two separate independent of each other movements.

3. An office chair base as defined in claim 1 and claim 2 with a hollow steel ball as a principal carrying element kept into position by a magnet.

4. An office chair base as defined in claim 1, claim 2 and claim 3 in which the only parts to be in contact with the horizontal surface, on which the movement is effectuated are the rotating tips of the supporting legs and the freely rotating, centrally located ball.

5. An office chair base as defined in claims 1, claim 2, claim 3 and claim 4 the horizontal movement of which is effectuated only by the freely rotating, centrally located ball and the rotating tips of the supporting legs.