Year: 1886

page_text: Date of Application, 26th Aug., 1886.
Complete Left, 21st May, 1887.
Complete Accepted, 21st June, 1887.
3
از
I, JOHN GIBB DUNLOP of 13 Fenchurch Avenue in the City of London, Engineer,
do bereby declare the nature of this invention to be as follows:-
In a revolving chair as it is usually arranged, particularly on ship-board, if its
frame be fixed at such a distance from the table that there is clearance for the back
when it is turned towards the table, then, on reversing the position, the seat is too far
away from the table to suit the comfort of the occupant. My invention relates to such
a construction of a revolving chair that the seat can be brought round to a convenient
position towards the table, whilst on reversing the position the back is clear of the
iable, and at the same time the act of turning the chair from the one position to
the other gives convenient room for passage of the occupant's limbs between his chair
and that next it. For this purpose, I connect a pin projecting down from the centre
of the seat by a radius rod to a centre pin on the fixed frame, or I arrange the downwardly
projecting pin to travel in a circular slot formed in the fixed frame. To the underside
of the seat I fix concentric with the pin a toothed pinion which gears with an internally
toothed circular rack of double the diameter fixed on the stationary frame. Thus,
when the seat is turned round the downwardly projecting pin as an axis, it is by the
sun and planet action of the rack and pinion caused at the same time to sweep in a
circular path round the centre of the fixed frame, the scat being thus made to
move in such a path that in any of its positions it suits the convenience of the
occupant.
Dated this 26th d
1000

page_text: I, JOHN GIBB DUNLOP, of 13 Fenchurch Avenue in the City of London, Engineer,
do hereby declare the nature of this invention to be as follows:-
-
In a revolving chair as it is usually arranged, particularly on ship board, if its
frame be fixed at such a distance from the table that there is clearance for the back
when it is turned towards the table, then, on reversing the position, the seat is too far
away from the table to suit the comfort of the occupant. My invention relates to such
a construction of revolving chair that the scat can be brought round to a convenient
position towards the table, whilst, on reversing the position, the back is clear of the
table, and at the same time the act of turning the chair from the one position to
the other gives convenient room for passage of the occupant's limbs between his chair
and that next it.
For this purpose I arrange under the seat of the chair gearing such as is shewn in
section in Fig. 1, (which is a side clevation of the chair), and in plan by Figs. 2 and 3.
1 connect a pin P projecting down from the centre of the scat S by a radius rod to a
centre pin on the fixed frame, or I arrange the downwardly projecting pin to travel in
a circular slot C formed in the fixed frame F underneath. To the underside of the
scat SI fix concentric with the pin P a toothed pinion W which gears with an
internally toothed circular rack R of double the diameter of the pinion, this rack
being fixed on or forming part of the stationary frame F. Thus, when the seat is
turned round the pin Pas an axis, it is by the sun and planet action of the rack R
and pinion W caused at the same time to sweep in a circular path round the centre of
the frame F, the scat being thus made to move in such a path that in any of its
positions it suits the convenience of the occupant. Instead of the rack I being
circular as shewn in Figs. 1 and 2, it may be straight as shewn in Fig. 3, the slot Č
being also straight.
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 combination with a revolving chair a pinion attached thereto and gearing with a
rack on the fixed frame of the chair, substantially as and for the purpose herein set
forth.
ABEL & IMRAY,
Agents for the Applicant.