Improvements in and relating to Swivelling Chairs.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Swivelling Chairs.
We, JAMES KIRKWOOD SHANKS, Engineer, of Beechfield House, and GEORGE
HEGGIE, Foreman Patternmaker, of Burnside Cottage, both in Denny, Stirling-
shire, do hereby declare the nature of our invention to be as follows:-
This invention has reference to improvements in and relating to swivelling,
eccentric or elliptical actions on chairs, suitable for ships' cabins, dining saloons
and other places, for giving convenient ingress and egress between the chairs of
a row, and for giving varied regulated distances of the front of the chair to or
from the table.
Two disc plates are used, the upper one being secured to the seat or revolving
part of chair, and the lower one to the bottom or fixed stand part of chair. Ac-
cording to our improvements the lower disc is formed with a pin or cam groove
part or about half of its length being cast or formed in one with the outer part
of disc, and the other part is made moveable, being fulcrumed on a pin at its
end adjacent to fixed part, and having its other or free end made adjustable in
towards the centre of disc, by having a thumb screw or like device working from
below through a slot in disc and engaging in cam slot formed in moveable rail.
The upper dise to which seat part of chair is fixed is formed with a slot through
which works a screw threaded bolt passed through a fixed eye at centre of lower
disc and round which the upper disc moves, while a pin in upper disc travels
in the fixed and moveable parts of channel groove in lower disc.
With this arrangement when the moveable rail is set and secured at its outer
extremity nearest edge of disc, the upper disc and seat will get its least travel
in towards the front of table that is, it has here its maximum back throw with
the top disc uncovering part of lower disc at front of table; while when the rail
is moved with its free end nearest the centre pin of disc the top disc will receive
its maximum throw in towards front of table overlapping the lower disc, and it
can be set and secured in any intermediate position between these by the thumb
screw working up into groove in rail through slot in lower disc. In moving
to give any of these positions the side throw of upper disc will always be the
same for clearing the neighbouring chair in approaching to or receding from tabl
By a modified arrangement the moveable rail part of groove would be fixed or
cast in one with the lower disc at any position between outer edge and centre
bolt and the whole groove would here assume much the shape of the two sides
of a heart shaped cam, but only one throw of upper disc would be here obtained
for giving one fixed distance in towards front of table.
Dated the 11 low of boy 1900

page_text: Improvements in and relating to Swivelling Chairs.
We, JAMES KIRKWOOD SHANKS, Engineer, of Beechfield House, and GEORGE
HEGGIE, Foreman Patternmaker, of Burnside Cottage, both in Denny, Stirling-
shire, do hereby declare the nature of our invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the followng statement reference being made to the accompanying drawings,
that is to say-
This invention has reference to improvements in and relating to swivelling
eccentric or elliptical actions on chairs, suitable for ships' cabins, dining saloons
and other places, for giving convenient ingress and egress between the chairs
of a row, and for giving varied regulated distances of the front of the chair to or
trom the table or passage and adjacent chairs.
Two disc plates are used, the upper one being secured to the seat or revolving
part of chair, and the lower one to the bottom or fixed stand part of chair.
And in order that our said invention and the manner of carrying same into
practice may be properly understood, we have hereunto appended.two sheets of ex-
planatory drawings in which Figure 1 is a plan of the top or movable plate.
Figure 2 is a sectional elevation through the centre line of top plate. Figure 3
is a plan of the lower or fixed plate. Figure 4 is a sectional elevation taken on
the line Y, Y³, and Figure is a sectional elevation taken on the line X1, X2,
of Figure 3. Figure 6, is a detached elevation of the moveable slot or rail.
Figure 7 is an elevation of both plates in their central position showing seat;
while Figure 8 is a plan view corresponding to Figure 7.
Referring to these drawings; -
According to our improvements the lower disc A Figure 3, is formed with a
pin or cam groove a, a, part or about half of its length being cast or formed
in one with the outer part of disc A, and the other part a' is made moveable, being
fulcrumed by a pin at its end adjacent working in a hole in a pap formed in
fixed part, and having its other or free end made adjustable in towards the centre
of disc, by having a thumb screw or like device 6 working from below through
a slot in disc and engaging in cam slot as formed in moveable rail a'. Instead
of the slot being of a straight formation as shown in Figure 3, it may be
formed of a suitable curved shape, and not require the slot in moveable part a
and the cam groove would not extend quite to the end of the latter; but this
arrangement would be defective in respect that the chair top would go past
centre line or at an acute angle, instead of being at right angles with table.
The upper disc B, Figure 1, to which seat part of chair is fixed is formed with
a slot Bi through which works a screw threaded bolt C, passed through a fixed
eye C¹, at centre of lower disc A and round which the upper disc B moves, while a
pin B2 in upper disc travels in the fixed and moveable parts a, a¹, of channel
groove in lower disc A.
With this arrangement when the moveable rail a¹, is set and secured at its
outer extremity nearest edge of disc, the upper disc B, and seat will get its least
travel in towards the front of table that is, it has here its maximum back throw
with the top disc B, uncovering part of lower disc at front of table; while when
the rail ¹ is moved with its free end nearest the centre pin of disc the top disc B,
will receive its maximum throw in towards front of table over-lapping the lower
disc A, and it can be set and secured in any intermediate position between these
by the thumb screw working up into groove in rail through slot in lower
dise A. In moving to give any of these positions the side throw of upper disc B,

page_text: will always be the same for clearing the neighbouring chair in approaching to
or receding from table.
Having now particularly described and ascertained the nature of cur said in-
vention and in what manner the same is to be performed, we wish it to be under-
stood that we are aware that in a specification on an application concurrent with
our present application for a patent, it has been proposed in eccentric swivelling
chairs for ships' saloons to combine an eccentrically grooved plate and a switch
or switches pivoted on such plate, the switch being adapted to direct a pin upon
the adjoining plate along a path having a greater or less degree of eccentricity in
order to adjust the seat in relation to a table and we make no general claim to
such an arrangement, but we declare that what we claim is :-
First. In swivelling chairs the forming of the lower or fixed disc plate with
a cam groove or rail, in which part made moveable so that its free end is ad-
justable towards the centre of disc, substantially as herein described in reference
to and shown in the accompanying drawings.
Second. The arrangement in combination of the parts of swivelling chairs for
giving varied regulated distances of the front of chair to or from the table or
adjacent chairs, substantially as herein described in reference to and shown in
the accompanying drawings.
Dated the 19th Nawal 1900