An Improved Method and Means of Mounting the Sitting or Supporting Parts of Chairs, Tables, and other Artioles of Furniture and the like.
Year: 1894

page_text: Date of Application, 12th May, 1894-Accepted, 16th June, 1894
COMPLETE SPECIFICATION.
An Improved Method and Means of Mounting the Sitting or
Supporting Parts of Chairs, Tables, and other Artioles of
Furniture and the like.
I, WILHELM DROESER, of Earls Court Square, London, Manufacturers' Agent,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to an improved method and means of mounting the sitting
or supporting parts of chairs, tables and other articles of furniture and the like,
with the object of causing the horizontal or approximately horizontal position of such
parts (hereinafter intended to be comprehended where the words "chair bottom"
alone occur) to be maintained, irrespective, within any required limit, of the position of
the legs or supporting frame thereof, so that whether the latter be standing on an
inclined floor or on a floor subject to alteration of position, such as the deck of a
vessel at sea, the chair bottom will, nevertheless, maintain its horizontality.
To this end, the invention consists in supporting the chair bottom in the line of
its centre of gravity, by a spherical or parti-spherical ball, which, in turn, is
supported in a normally horizontal plane below and adjacent to its central horizontal
plane of greatest area, by ball-bearings contained in a rigid frame, supported by
legs or a suitable framing, and, also, in causing the chair bottom to be maintained
in stable equilibrium by the application of its own weight to the ball or to a
depending extension thereof, at a point as much below its plane of support as is
conveniently obtainable, or by the application of a gravity device suspended in the
line of the centre of gravity of the chair bottom, or by such means operating
conjointly, with the object of bringing said centre of gravity as much below the
plane of support of the ball as is necessary to obtain a sufficient stability of the
chair bottom.
With such an arrangement; however, within the arranged limit, the normally
horizontal plane of support afforded by the ball-bearings may oscillate or assume
various inclined positions, such, for example, as would be caused by the pitching
and rolling of a vessel at sea; still, as such plane of support or its major part will
always be below and on the opposite side of the parallel plane of greatest area of the
ball to that on which the chair bottom is situated, both the ball and the attached
chair bottom will be supported in stable equilibrium, by reason of the application
of its weight to the ball at a point below its plane of support, or of the gravity
attachment applied to the ball, or of such forces operating conjointly, and the
horizontality of the chair bottom will, consequently, be maintained.
On the accompanying drawings-
Fig. 1 represents an elevation, partly in section on the line 1-1, Fig. 3, of a
chair bottom mounted in accordance with the invention.
Fig. 2, represents an elevation showing the position on an inclined floor,
Fig. 3, represents a plan, the chair bottom having been removed.
a, represents the chair bottom, table top or other sitting or supporting part of the
article, the horizontality of which it is wished to maintain, and b, represents the
said spherical or parti-spherical ball upon which the chair bottom is mounted and
which constitutes its centre of adjustment.
It is only necessary that a central zone of the ball, sufficient to provide (say)
for usual inclinations of the deck of a vessel at sea, should be spherical. Its top
may be truncated, as at b, and its upper part may also be hollowed, as at 6², to
reduce the weight above its plane of support afforded by the ball-bearings c; it is

page_text: preferably solid below such plane to assist in the desired gravitating action, but is
made hollow in the line of its axis, as at 3, to enable the chair bottom to be connected
to and its weight applied to the ball or to a depending extension thereof at a point
below its plane of support for the purpose aforesaid.
In Fig. 1, the ball is represented as formed with an axially hollowed depending
extension, 6, and the weight of the chair bottom is represented as applied to said
extension, well below the plane of support of the ball afforded by the ball-
bearings, by means of a standard a', which is screwed to the underside of the
chair bottom, is centred in the upper part of the recess, 63, by a loosely fitting
collar, a, and is screwed into the bottom of the recess, as at a. The chair bottom
may, however, be applied to the ball in any other suitable manner which will
enable it to depend upon the ball for its horizontality.
In Fig. 2, the ball is represented as also formed or provided with a depending
gravity device, 64, which may be of any suitable ornamental formation, and may
be formed integral with the ball, or may be adjustably applied thereto in any
. Buitable manner.
c, represents the ball-bearings, which are applied to a rigid, normally horizontal,
annular frame, c', in a plane below that of the greatest area of the ball, b, either
singly and equidistant in pockets, c³, as represented, or in adjacent series in a
grooved annular frame.
The frame, c', is supported by legs, c³, which, at a lower part, may be braced
together by an annular guard, e, or it may be otherwise supported in any
convenient manner.
The balls, c, are located in position by a removable cover-ring d, secured by
screws, d', and they may be set up or adjusted to the ball, b, by set-nuts, c³.
The cover-ring, d, serves also to connect the ball, b, with the supporting
frame, c, e, in such a manner as to enable the whole article to be lifted, and readily
removed from place to place.
The chair bottom may be tilted in any direction by the inclination of the body
of the user, within limits defined by an annular stop, 6, formed on the lower part
of the ball, b, and adapted to co-act with an annular stop, c, formed on the under
side of the frame, e. Such stops may also serve to define the limit of inclination
of the floor, within which the ball and gravity device will maintain the desired
stable equilibrium of the chair bottom or other article supported by the ball.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
In means for mounting the sitting or supporting parts of chairs, tables, and other
articles of turniture and the like:-
1. Causing the horizontal or approximately horizontal position of such part to be
maintained, irrespective, within the required limits, of the inclination of the floor
on which the leg supporting frame of the article rests, by supporting such part, in
the line of its centre of gravity, by a spherical bearing, which is supported, in a
plane adjacent to its horizontal plane of greatest area, by ball-bearings contained
in a rigid annular frame supported by the leg framing, and by causing the stable
equilibrium of such part so supported to be maintained by the application of its
own weight to the spherical bearing, or to a depending extension thereof, at a point
below its plane of support, both with and without the application to such bearing
of a depending gravity device, as set forth.
2. In combination; a chair bottom, table-top or other sitting or supporting part
of an article of furniture or the like; a spherical bearing truncated at its top,
hollowed at its upper part, formed or provided with a depending extension or
gravity device, and recessed in the line of its centre of gravity to a point below its
plane of support; means for connecting the chair bottom, table-top or other part
to be supported with the spherical bearing or depending extension thereof in the
line of its centre of gravity and below its plane of support; ball-bearings for

page_text: supporting the spherical bearing in a plane adjacent to its horizontal plane of
greatest area; a rigid annular frame supporting the ball-bearings; a depending
leg-framing supporting the annular frame; and a cover-ring locating the ball-
bearings in the annular frame, and connecting the spherical bearing to the supporting
framing so as to permit of the lifting and removal of the whole upon lifting the top
supported part, as set forth.
Dated this 10th day of Mov 1804
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.