IMPROVEMENTS IN ADJUST- ABLE CHAIRS
Year: 1878

page_text: LETTERS PATENT to George Wilson, junior, of 12, Wilson Street, Finsbury, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN ADJUST-
ABLE CHAIRS." A communication from abroad by George Wilson, of Brooklyn,
New York, in the United States of America.
Sealed the 10th September 1878, and dated the 16th March 1878.
PROVISIONAL SPECIFICATION left by the said George Wilson at the Office
of the Commissioners of Patents on the 16th March 1878.
GEORGE WILSON, junior, of 12, Wilson Street, Finsbury, in the County of
Middlesex. "IMPROVEMENTS IN ADJUSTABLE CHAIRS." (A communication from
abroad by George Wilson, of Brooklyn, New York, in the United States of
America.)
•
This Invention has reference principally to chairs destined for surgical purposes
or dentistry, or to be used by invalids, but is also applicable in any or all of its..
features to any easy or reclining chair, and consists principally in mechanism, by
which different changes in the position of the chair can be effected. This is so con-
trived that the person sitting in the chair can, without rising, shorten the seat, so
as to push himself forward, raise or lower the chair seat, cant it and the back to
any angle, and bring the leg supports more or less to a horizontal position, and in
whatever position the respective parts may be set, they will remain without the
necessity of employing any locking device.
The Invention consists,-
Firstly. In the combination of two leg rests pivoted separately to the seat of the
chair, and set at any angle by means of a screwed shaft rotated through gears, and
operating for that purpose through pivoted links.
Secondly. In a scat carried on slides moving vertically on guides, and raised or
lowered by gearing through the intermediation of a screwed rod.
Thirdly. In combining with the seat of an adjustable chair an arc, having formed
on it a rack, in which intermeshes a worm formed on a countershaft, driven by
gears.

page_text: Fourthly. In the back pivoted to slides running on the side rails of the seat,
these slides carrying a shaft, on which are mounted pinions, working in racks on the
under side of the side rails.
Fifthly. In combining with the back of an adjustable chair a link pivoted thereto,
and to a toothed are pivoted to the slide or side rail, and acted upon by a worm on
a countershaft rotated through gearing.
By this means an adjustable chair is formed, which can be made to assume any
desired position, all its movements being accomplished, either separately or in com-
bination, by means of gears, the operating points of which are within the reach of
the occupant of the chair.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Wilson in the Great Seal Patent Office on the 16th
September 1878.
GEORGE WILSON, junior, of 12, Wilson Street, Finsbury, in the County of
Middlesex. "IMPROVEMENTS IN ADJUSTABLE CHAIRS." -(A communication from
abroad by George Wilson, of Brooklyn, New York, in the United States of
America.)
This Invention which has reference principally to chairs destined for surgical
purposes, or in dentistry, or to be used by invalids, but is also applicable in any or
all of its features to an easy or reclining chair, consists principally in the mechanism
whereby the different changes are effected. This is so contrived that the person
sitting in the chair can, without rising, shorten the seat, so as to push himself
forward, raise or lower the chair seat, cant it and the back to any angle, and bring
the leg supports more or less to a horizontal position; and in whatever position
the respective parts may be set, they will remain without the necessity of employing
any locking device.
For full comprehension, however, of the Invention, reference must be had to the
annexed Drawings, in which,-
•
Figure 1 is a side view of the Invention.
Figure 2 is a part plan view, showing arrangement of leg supports.
Figure 3 is a back view of chair, showing arrangement for raising seat.`
Figure 4 is a part side view, broken away to show mechanism for shortening
seat.
Figure 5 is a side view, showing mechanism for altering angle of seat and
back.
Figure 6 is a view showing arrangement for raising leg supports.
Similar letters of reference indicate like parts.
A, A, are arcs which form the stand of the chair, and have their lower ends pre-
ferably mounted on castors a, and connected by bars A¹, these in their turn being
braced by transverse rods A³, and connected with the upper part of the ares by
vertical stays A³ acting as guides in the mechanism now to be described, and shown

page_text: in Figure 3, for raising the seat B. This sent B has on its under side two lugs b, b,
through which and the slides B', B¹, passes the_rod C, having a square end c, so as
to be turned by any suitable crank handle. Upon this rod C are mounted bevel
gear wheels C, C₁, intermeshing with like gears D', D', on the upper end of the
screwed rods D, D, carried in brackets d, d, secured to the slides B', which clip
guides As, and working in suitably threaded eyes D³, D³, formed in brackets d', di,
secured to the stand A or bar A¹.
It will easily be seen that the rotation of the rod C will through the gears C', D¹,
raise and lower the screwed shafts D, and with them the above mechanism and the
seat B, as shown in the dotted lines, Figure 1. The slides B¹ working up and down
on the guide A³ ensuring perfect vertical movement.
The supports for the legs and the mechanism for altering their position are shown
more particularly in Figures 1, 2, and 6, and may be thus described.
E, E, are forked pieces pivotted at e, c', to a cross bar of the seat B, and having
attached to them by suitable pivot pins, leg rests F, F'. These rests F, F', have,
as shown, pivotted to them links ff, provided at their ends with hooks to hold on
to corresponding bars secured to the transverse bar g, carried at and connecting the
free ends of the loose arms G, pivotted, as shown, to the front bar of the seat
H, H', are links pivotted, as shown, to the arms G, and having secured
to their inner ends screwed eyes h, h¹, in which work the screwed shafts I, rotated
by means of bevil gear wheels I' mounted thereon, and intermeshing with other
gears K¹, carried on the ends of a rod K. (all supported in suitable bearings carried
by the side rails of the seat B and arcs B² attached thereto) provided with a square
end, by which it can be turned.
As will be easily seen, the rotation of the shaft K will, through the screwed shaft I
move back and forth as may be desired, the eyes h, h¹, drawing with them the
links H, H¹, connected with the loose arms G, thus through the links f tilting up
or lowering the leg rests F, F', to which are respectively pivotted the feet stands
L, L', secured at any angle desired by set screws.
The arrangements by which the leg rests are kept independent of each other will
be found of great use where it is desired to rest, dress, or operate upon one only,
and stirrups,, which may at pleasure be attached thereto, will be of great assist-
anco in many instances as rests for the feet.
Along a portion of the arcs B2, secured as before mentioned to the seat B, and
preferably at their lowest points, are attached, as at B³, racks, in which work worms
m, formed on the countershafts M, rotated by means of the gear wheels M'; which
intermesh with the gears N¹ on the shaft N, having, as before described, a square
end to be more easily rotated.
The above described mechanism, shown more particularly in Figure 5, serves to
tilt the seat B either forward or backward, the turning of the rod N causing the
worm m to act upon the rack B³, formed on the arc B³, raising and lowering its ends,
and thus altering the angle of the seat. The whole of these parts are carried in
brackets secured to the slides B', so as to be connected with and form part of the
mechanism for raising the seat.
O, O, are the side rails of the chair back connected together by any desired
arrangement of transverse bars, and pivotted to slides P, moving on the seat B; to
these slides P are also pivotted toothed arcs Q connected by links O¹ with the
rails O, and operated upon by a worm r on the countershaft R, rotated through
gears R, S, by the shaft S, these last being carried in bearings T, hung on the
pivot pin p. To these slides P are attached projections P¹, held close up to the
seat rails by clips P2, and forming bearings for a shaft U, on which are mounted
pinions U¹, intermeshing with racks V forined, as shown in Figure 4, on the under
side of the seat rails. These devices act upon the back of the chair, the rotation of
the pinion U', in the rack V, drawing the slide P, and with it the back rails O and
dependent parts towards the front of the chair.
Again, by turning the shaft S, the action of the worms 7 thus rotated will through
the toothed arcs Q and links O' operate to alter the angle of the chair back; W, W,

page_text: are the chair arms, which may be set at any angle by the curved braces X, X, locked
by any desired fastening.
It will thus be seen that the above-described mechanism can be operated by the
occupant of the chair, all the motive parts being within reach of bis hands, and also
that all the movements being made by worms or gears, no locking device is needed
to retain the several parts in their relative positions.
In addition to these features the parts have been so arranged that by any com-
bination two or more of the several adjustments can be formed.
And having now described the nature of the said Invention, and in what manner
the same is to be performed, I declaro that I claim,-
First. In any adjustable chair the combination therewith of the leg rests E, E¹,
pivotted separately to the seat, and set at any angle by means of the screwed shaft I,
rotated through gears, and operating for that purpose through pivotted links, all
substantially as heroin set forth.
Secondly. The seat B carried on slides B¹, moving vertically on guide A³,
and raised or lowered by gears operating the screwed rod D, all as herein set
forth.
Thirdly. In combination with the seat B of an adjustable chair an arc B², having
formed on it a rack, in which intermeshes a worm formed on a counter shaft, driven
by gears, all as and for the purposes herein set forth.
Fourthly. In adjustable chairs, the back pivotted to slides running on the side
rails of the seat, these slides carrying a shaft, on which are mounted pinions
working in racks on the under side of the side rails, all as and for the purposes
herein set forth.
Fifthly. In combination with the back of an adjustable chair, a link pivotted
thereto, and to a toothed are pivotted to the slide or side rail, and operated
upon by a worm on a countershaft, rotated through gears, all as and for the purposes
herein set forth.
Sixthly. An adjustable chair, in which the separate leg rests may be set to any
angle, the seat raised or tilted either forward or backward, and the back set at any
angle, or brought forward, all these movements being accomplished, either separately
or in any combination, by means of gears, the operating points of which are within
the reach of the occupant of the chair, all as herein set forth.
In witness whereof, I, the said George Wilson, junior, have herounto set my
hand and seal, this Twelfth day of September, One thousand eight hundred
and seventy-eight.