GB2291341A

GB2291341A - Self-lubricating system for adjustable chair

Info

Publication number: GB2291341A
Application number: GB9414850A
Authority: GB
Inventors: Harry Hung Song Teo
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-07-22
Filing date: 1994-07-22
Publication date: 1996-01-24
Anticipated expiration: 2014-07-22
Also published as: GB9414850D0; GB2291341B

Abstract

Apparatus for supporting an adjustable chair between upright and reclining positions comprises an angular bar 20 beneath the seat portion 10 is coupled to the side edges 16 of the seat portion. One end of a cylinder 26 is coupled to the bar 22 the other end of the cylinder having an opening for a concentric shaft 30 so that the remote end of the shaft can be coupled to the underside of the seat portion for guiding the seat. At least a pair of concentric guides are disposed in the interior of said cylinder for guiding the lateral movement of the shaft. Disposed in the cylinder and around the shaft is an absorbent cylinder of oil obsorbing felt for lubricating the shaft as the chair is adjusted. A base plate vertical column is coupled to the intersection of the angular bar and the cylinder for supporting the adjustable chair. <IMAGE>

Description

SELF-LUSICRIN SYSIIEM R AWUSTABLE CHAIR The present invention relates to adjustable furniture, and in particular to a self-lubricating system for changing the angle of recline and balancing the weight of an adjustable chair.

Ajustable chairs are well known in the furniture industry. However, a majority of the prior art adjustable chairs require extra levers to maintain in a particular reclining position. Moreover, few adjustable chairs allow an user to recline in a natural position without expensive and complicated accessories.

U.S. Patent No. 4,984,846 disclosed an adjustable chair having an articulation means between a seat member and a back rest member and permitting the seat member to be displaced along a sliding path. The sliding path is made of one or more curved sliding means between the seat member and seat support. Although the '846 claimed to experienced smaller friction than prior art models, the construction of the articulations means and the sliding means is costly and complicated.

U.S. Patent No. 3,876,248 taught an extendible and contractable connecting link assembly connecting a stationary horizonatally disposed seat bench member and a pivotally mounted seat bench member. The '248 prior art is more suitable for automotive and aviation seats where a horizontally disposed seat is given. The link assembly is however featured with a fulcrum means for maintaining adjustable position of the back seat.

The present invention discloses an apparatus for supporting and lubricating an adjustable chair as the user manoeuvres the chair from an upright position to an reclining position or vice versa. The apparatus comprises an angular bar beneath the underside of the seat portion of the adjustable chair. The angular bar is coupled to the side edges of the seat portion. One end of a cylinder is coupled to the middle section of the angular bar in a "T" configuration. The other end of the cylinder has an opening for accommodating a concentric shaft so that the exposed end of the shaft is coupled to the underside of the seat portion for guiding the lateral movement of the seat relative to the longitudinal axis of the cylinder. At least a pair of concentric stopper are disposed in the interior of said cylinder for guiding the lateral movement of the shaft.Preferably, the stoppers are made of teflon plastic. Disposed in the cylinder and between the pair of concentric stoppers is an absorbent cylinder made of oil obsorbing felt for lubricating the shaft as the user shifts the body weight to adjust the chair. And disposed between the interior surface of the cylinder and the outer surface of the selflubricating sub-assembly comprising of plurality concentric stoppers is a thin concentric tube which fits tightly therebetween so as to prevent any leakage.

The base plate and a vertical column is coupled to the intersection of the angular bar and the cylinder for supporting the adjustable chair.

FIG. 1 illustrates a perspective, bottom right hand elevational view of an adjustable chair in an upright position being retrofitted with a self-lubricating system according to the present invention.

FIG. 2 shows a perspective, bottom right hand elevational view of the same adjustable chair in an reclining position being retrofitted with the self -lubricating system according the preferred embodiment of the present invention.

FIG. 3 is a cross sectional right side elevational view of the self-lubricating system of the present invention being in a fully upright position of the adjustable chair.

FIG. 4 is an exploded perspective bottom right side elevational view of the various components of the self-lubricating system of the present invention.

FIG. 1 illustrates a perspective, bottom, right hand elevational view of an adjustable chair in an upright position being retrofitted with a selflubricating system according to the present invention. An adjusting chair 10 has a back portion 12 which is coupled to a seat portion 14 with a pivot (not shown). The plane parallel to the back portion and the seat portion respectively comprises an angle Q 15. Referring again to FIG. 1, the seat portion 14 has two arm rests 16 on its side edges. The arm rests 16 extends vertically below the underside of the seat portion.

The present invention comprises an angular bar 20, a cylinder 26 and a supporting bracket 32. The angular bar 20 is coupled to the side edges of the seat portion or alternatively the inner surfaces of the arm rests 16 for distributing the weight of the person or object exerting on the seat portion.

Both ends of the angular bar 20 is secured to the arm rests with a bracket 23 and appropriate bolts. There is an angle 6 24 between the side bars 22 of the angular bar 20. Based on experimentai data, the optimum angle is less than 60 degrees. One end of the cylinder 26 is coupled to the middle section of the angular bar 20 over the supporting bracket 32. The supporting bracket has a cavity in the centre for accommodating the vertical column (not shown) from the base plate (not shown). The other end of the cylinder 26 has an opening for receiving a concentric shaft 30. Further details of the cylinder and shaft will be described in FIGS. 3 and 4. The exposed end 28 of the shaft is coupled to a fitting on the underside of the seat portion 14.

The combination of the cylinder with the pivoting back and seat portions of the adjusting chair enables a person to adjust the chair by merely shifting the body weight.

FIG. 2 shows a perspective, bottom right hand elevational view of the same adjustable chair in an reclining position being retrofitted with the self -lubricating system according to the preferred embodiment of the present invention. The adjusting chair in FIG. 2 is substantially similar to that in FIG.

1 with the exception of the angle Q' 17 and the extension of the shaft 30.

The angle Q' 17 is wider than the angle Q 15 because the former is in a reclining position. Similarly, the shaft 30 is fully extended outside of the cylinder 26.

FIG. 3 is a cross sectional right side elevational view of the selflubricating system of the present invention being in a fully upright position of the adjustable chair. The angular bar 20 is shown being coupled to the supporting bracket 32. In the preferred embodiment of the present invention, the supporting bracket is welded onto the angular bar. In the same way, one end 31 of the cylinder 26 is also welded onto the the supporting bracket 32 such that the longitudinal axis of the cylinder and that of the supporting bracket forms an angle a 33 therebetween.

Referring again to FIG. 3, the other end 29 of the cylinder is open ended for receiving a concentric shaft 30. It should be understood by one skilled in the art that the shaft has a diameter smaller than the inner diameter of the cylinder. The shaft has two ends 28 and 38. The shaft end 28 is exposed and has a pin for coupling with a bracket and bolt (not shown) that is secured to the underside of the seat portion. The unexposed end 38 terminates in a small bore for receiving a stopper pin 40. Disposed in a concentric fashion with the shaft 30 are a plurality of stoppers for guiding the shaft as it moves back and forth the cylinder. A stopper 42 having a cylindrical shape is secured within the interior of the cylinder for limiting the extent the shaft may move forward. The stopper pin 40 stops the forward progress of the shaft 30 when the pin stops at the end part 35a of cylinder 35 nearest to stopper 42. Preferably, the stopper is made of steel. Similarly, at the end 29, when the shaft moves backward, the rubber stopper 36 will be stopped by a seal 34 as the chair is moving to an upright position. Disposed further within the interior of the clyinder are at least a pair of stoppers 44 and 46 respectively for guiding the shaft 30 Within. the cylinder. Preferably, the

stoppers 44 and 46 comprise TEFLON < plastic. Disposed between the stoppers 44 and 46 is also a stopper 48 for centering the shaft 30.Between the stopper 48 and the stopper 46 is an absorbent cylinder 50 for retaining certain amount of lubricant and lubricating the shaft 30 within the cylinder 26. Preferably, the absorbent cylinder is made of oil obsorbing felt or any similar absorbent material. To prevent oil from leaking within the cylinder as the shaft moves back and forth, another smaller cylinder 35 is disposed therebetween the inner surface of cylinder 26 and the surface of a selflubricating subassembly which comprises of the plurality of stoppers and oil obsorbing felt.

FIG. 4 is an exploded perspective bottom right side elevational view of the various components of the self-lubricating system of the present invention. It should be understood by one skilled in the art that the outer diameter of the encasing cylinder 35 is slightly smaller that of the clylinder 26 and slightly larger than the self-lubricating sub-assembly such that said self-lubricating sub-assembly can be fitted snuggly therein. It follows that a simple self-lubricating clylinder for balancing and supporting a person in an adjusting chair has been described. By merely shifting the body weight, the user may recline into a comfortable angle without using any levers or balancing assessory. Furthermore, the user in a recline position can return to a upright or intermediate position by simply shifting the weight of one's body forward. The present invention may be retrofited on any pivotally mounted adjustable chair.

While the present invention has been described particularly with reference to FIGS. 1 to 4 with emphasis on a self-lubricating system for adjustable chair, it should be understood that the figures are for illustration only and should not be taken a limitation on the invention. In addition, it is clear that the method and apparatus of the present invention has utility in many applications where balancing and improved lubrication of adjustable furniture are required. It is contemplated that many changes and modifications may be made by one of ordinary skill in the art without departing from the spirit and the scope of the invention as described.

Claims

1. A self-lubricating system for adjustable chair1 said chair having at least a back portion and at least a seat portion, said back and seat portions being coupled with a pivot for adjusting an angle fl between said back and seat portions, said seat portion further having two side edges, the underside of said seat portion being further supported in an upright position with a base plate and column, said self-lubricating system comprising:: an angular bar beneath said seat portion and between said underside of said seat portion and said base column for distributing the weight of a person seating on said adjustable chair, said bar having an angle ss between the cross sectional axis thereof; a cylinder beneath said seat portion and coupled at one end to the middle section of said angular bar for enhancing the pivoting movement of the adjustable chair as the user adjusts the chair through the angle Q between said back and seat portions, the other end of said cylinder having an opening for accommodating a concentric shaft, the exposed end of said shaft being coupled to the underside of said seat portion for sliding said seat portion in a lateral motion relative to the axis of said cylinder; ; at least a pair of stoppers disposed in the interior of said cylinder for guiding said shaft as it moves back and forth within said cylinder; and at least one absorbent cylinder disposed within said cylinder and between said pair of stoppers for lubricating said shaft whereby said chair may be adjusted by the user without effort.

2. The system as defined in claim 1, wherein said angle ss is no more than 160 degrees.

3. The - svstem as defined in claim 1, wherein said stoppers

comprise TEFLONlplastic.

4. The system as defined in claim 1, wherein said absorbent cylinder comprises felt.