Description:
FORM 2
THE PATENTS ACT 1970 (39 of 1970)
&
THE PATENTS RULES, 2003 COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION

NEW TECHNOLOGY SEATING STEEL CHAIR

2. APPLICANT

(i) NAME : The Principal.
(ii) NATIONALITY : INDIAN
(iii) ADDRESS : St.Mother Theresa Engineering College,
Vagaikulam, Thoothukudi-628102, Tamilnadu,
India.

2. PREAMBLE TO THE DESCRIPTION

The following specification particularly describes the invention and the manner in which it is to be performed.

Title: New technology seating steel chair.

Description:
FIELD OF THE INVENTION

This invention relates to a new technology steel chair for the industrial and office environment.

BACKGROUND OF THE INVENTION

Seated workers in the industrial and office environment often experience back pain and other physiological difficulties as a result of prolonged sitting in a fixed posture. Much research and analysis has been conducted into so-called ergonomic chair design to provide solutions to these difficulties.

It has been suggested, therefore, that a suitable chair, in order to fit into its working environment, should be adjustable in the following ways: (1) the seat height should be adjustable; (2) seat depth should be adequate for large people without being too large for smaller workers; (3) seat padding should be adequate to allow pressure to be distributed but not so soft that the seat bones of the pelvis (the ischial tuberosities) bottom out; (4) the seat pan should be capable of tilting forward and backward; (5) the back should be alternately positionable both upright and with a backward tilt; (6) the backrest should be padded and have a lumbar support; (7) the chair should have both a dynamic range of posture movements without the worker making adjustments, and multiple static posture settings which can be engaged to lock the chair into any position set by the worker.

SUMMARY OF THE INVENTION

A major object of the present invention is to provide an steel chair that maximizes the objectives of the above-suggested adjustabilities. A further major object is to provide a steel chair that provides the aforementioned postural options, each with a dynamic range of posture movements. Another object of this invention is to provide such a steel chair that is capable of being set to provide the five aforementioned postural options; upright (the upright chair), backward-tilted backrest (the "Grandjean" chair design), forward tilted seat pan (the "Mandal" chair design); knee-supported (the "Balans" chair design); and the "standing" chair. A further object of this invention is to provide such a steel chair that may permit a worker to assume other postures as might be desired for working, resting or lounging. Still another object of this invention is to provide such a steel chair that might be used in environments other than in the workplace and at a work station.

DETAILED DESCRIPTION OF THE INVENTION

The steel chair of this invention comprises a front seat assembly 10, a rear seat assembly 12, and a base assembly 14. The base assembly supports the front and rear seat assemblies and spaces them apart. The front seat assembly is mounted to the base assembly and provides a front seat 20 capable of pivotal movement about a horizontal axis 16. The rear seat assembly is mounted to the base assembly and provides a rear seat 22 capable of pivotal movement about a horizontal axis 18. The base assembly mounts the front seat assembly by means of a telescopically adjustable upright front mounting assembly 24. The base assembly mounts the rear seat assembly by means of a telescopically adjustable upright rear mounting assembly 26. Thus, the heights of the front and rear seat assemblies are independently adjustable. The front and rear mounting assemblies may be manually adjustable, as shown with reference to FIGS. 2 and 4, or they may be pneumatically adjustable, as shown with reference to FIGS. 1 and 3.
The base assembly comprises a main horizontal steel member, which may be a steel bar 30 as shown in FIG. 1 or a steel tube 130 as shown in FIG. 2; front and rear upright steel extension lift sleeves, which may be steel cylinders 32-34 as shown in FIG. 1 or steel tubes 132-134 as shown in FIG. 2, welded to and extended upwardly from the main horizontal member 30, or 130; and front and rear floor support frames 36-38 which may be steel tubes welded into a rectangular framework with depending front and rear pairs of legs 40-42. The legs may mount floor castors 43 which elevate the front and rear floor support frames so that main horizontal member 30, or 130, will just clear the floor on the order of about 3/4 inch (providing just enough clearance to clear the loft of any carpeting on which the steel chair is placed). The front floor support frame is welded to the front side of the extension lift sleeves 32 or 132, and extends forward, ahead of the front seat mounting assembly 24 as shown in FIGS. 1 and 2. The rear floor support frame is welded to the front side of the extension lift sleeves 34 or 134, and extends rearward, behind the rear seat mounting assembly 26 as shown in FIGS. 1 and 2. The width of the support frame rectangles is sufficient to provide lateral stability for the steel chair against tipping over; about 15 inches being adequate. The front floor support frame provides a front cross-rail 36a that may double as a foot rest, at an elevation of about 5-6 inches for example. Likewise, the rear floor support frame provides a forward cross-rail 38a that may double as a heel rest, at an elevation of about 5-6 inches for example. The main horizontal member 30, or 130, is a structural beam that locates the front and rear mounting assemblies, front to rear, at a desired distance apart; about 17 inches being adequate. It is preferable that the base assembly 14 include structure providing an elevated foot support cross-rail such as rail 36a, but neither it nor heel cross-rail 38a are necessary. The elevated front and rear floor support frames enable the use of the four depending legs 42 which provide for stable 4-point floor support; the small degree of elevation of the main horizontal member 30, or 130, preventing "high centering" of the steel chair.
, Claims: CLAIMS

We claim:

1. An steel chair comprising front seat assembly means, rear seat assembly means, and base assembly means, the base assembly means supporting the front and rear seat assembly means independently of one another; said front seat assembly means having a front seat pivotally mounted for rotation about a horizontal axis, said axis defining a front seat fulcrum; and said rear seat assembly means having a rear seat pivotally mounted for rotation about a horizontal axis, said axis defining a rear seat fulcrum; the two rotation axes being separated from one another a sufficient distance that a person may sit on the front seat and position his or her back against the rear seat; said front seat having a configuration adapted to support a sitting person and being so configured and positioned with respect to said rear seat whereby a sitting person may be supported by the front and rear seats with his or her sacrum, coccyx and ischial tuberosities clear of bearing contact with said front seat; said rear seat being provided with a rear seat cushion having a length sufficient below its horizontal axis of rotation to support the spinal dorsal region of a person sitting in the chair and a length sufficient above its horizontal axis of rotation to support the spinal dorsal region of a person sitting in the chair whereby a sitting person's spinal sacrum region will be supported as a result of a sitting person's upper back levering said rear seat into contact with the sitting person's sacrum region; said rear seat cushion being configured to provide an elongated narrow portion extending above its horizontal axis of rotation and to provide a wider mid portion adjacent the region of its horizontal axis of rotation, whereby said rear seat cushion may support a sitting person's upper and lower back regions without contacting his or her shoulders.