IMPROVEMENTS IN ADJUSTABLE CHAIRS, CHIEFLY DESIGNED FOR THE USE OF DENTISTS AND HAIR DRESSERS
Year: 1879

page_text: 16
LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, &
Co., Patent Agents, Southampton Buildings, London, for the Invention of
IMPROVEMENTS IN ADJUSTABLE CHAIRS, CHIEFLY DESIGNED FOR THE USE OF
DENTISTS AND HAIR DRESSERS." A communication from abroad by George
Washington Archer, of Rochester, New York, United States of America,
Manufacturer.
Sealed the 22nd August 1879, and dated the 3rd March 1879.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 3rd March 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN ADJUSTABLE CHAIRS, CHIEFLY
DESIGNED FOR THE USE OF DENTISTS AND HAIR-DRESSERS." [A communication
from abroad by George Washington Archer, of Rochester, New York, United
States of America, Manufacturer.]
This Invention relates to improvements in adjustable chairs, chiefly designed for
the use of dentists and hair-dressers, and comprises a novel construction and
arrangement of parts for supporting and adjusting the same.
In carrying the said Invention into practice, I construct the base or supporting
frame of the chair of cast iron, and in two pieces, which are counter parts. The
central portions fit together face to face and are united by screws. The lower ends
branch outward and form four legs, and the upper ends branch outward and form
two bearings, provided with inwardly projecting pivots, which receive and support
the chair-body and allow it to turn.
In the central portion of the frame is a cavity in which rests a segment attached
to the foot-rest frame of the chair, and also a pivoted pawl which engages with
notches in the said segment. The end of the said pawl extends out through the
rear of the frame in position to be acted upon by the foot. The said segment is
pressed down in the said cavity to hold it in engagement with the pawl by a coiled
spring. At the outer end outside of the frame this segment has a cross-head which

page_text: extends from side to side of the foot-rest frame, and is pivoted thereto so that the
said segment can turn to adjust itself to position.
The chair body consists of a seat and back. The seat is attached to the top of
the foot-rest frame by screws. The said foot-rest frame consists of two arms
extending downward (to which the aforesaid segment is pivoted, as hereinbefore
described) and a foot rest proper at the lower end, at the extremity of which is an
upright bracket or frame. These are all cast or formed in one piece, and being
attached to the chair body they adjust with it.
The back is attached to the seat by a cast iron frame on each side. The frames
are attached to the seat by lugs, and at the top they have horizontal flanges to
which the arms are screwed. At the rear they have right angled flanges which
embrace the edges of the back, being screwed thereto.
Figure 1 is a side elevation of my improved chair.
Figure 2 is a perspective view of the fixtures, the chair being removed from the
same, and
Figures 3 and 4 shew portions of the same detached.
Like letters indicate the same parts throughout the Drawing.
A represents the base or supporting part of the chair, the said base being made of
cast-iron in two parts. The central portions a, a, fit together, forming a solid body
in the middle, and are united by screws b, b, b, as shewn. The lower ends form
the legs c, c, c, c, while the upper ends branch outward laterally and form the
bearings d, d, to which the chair-frame is attached by pivots f, f, cast solid on the
parts a, a. h, h, are cavities or slots on the inner faces of the central parts a, a, in
which the segment and cam fit, as will be hereinafter more fully described. When
.1

page_text: the parts are fitted together these cavities are enclosed, with the exception of an
opening at the front and rear for the admission of the segment and cam.
D is the supporting frame for the chair E, and D¹ is the foot-rest which forms a
part of the said supporting frame. These parts are also made of cast-iron and in
one solid piece. The frame has two horizontal plates i, i, at the top, the said plates
being bolted or screwed to the bottom of the chair. From these plates extend
angular arms or brackets k, k, which are provided with holes which fit upon the
pivots ff, above described. At the bottom of these arms is the horizontal foot-
rest platform, and outside of this the ornamental bracket m. The frame and
foot-rest being formed in one piece and attached firmly to the bottom of the chair,
the whole forms one adjustable structure, and the foot-rest therefore requires no
separate adjustment as in other chairs of the kind.
G is the segment which works through the sloth and consists of a curved arm n
and a right angled cross-head o, which has lugs o¹ pivoted to corresponding lugs
of the arms k, k, near their bottom. The jointing or pivoting of the crosshead
allows the segment to follow the slot without binding as the chair is adjusted to
different heights. The segment has a notch p which catches over the edge q of the
part a when the chair is thrown back in the position shewn in Figure 1. The
segment is pressed down to form this engagement by a coiled spring in the part a.
At the rear end the segment has a hook shaped head 8, which strikes the stop t and
prevents the segment from being drawn out of the slot.
H is the lever forming the cam; it is pivoted centrally by one of the screws
which unite the halves of the base or by other suitable means. One arm rests
under the segment G while the other extends out through the slot and forms the
treadle for the foot of the operator. By pressing on this lever he can raise the
segment to allow the chain to fall.
The cast iron base made in halves is cheap and simple, and avoids the necessity
of legs attached directly to the body of the chair. Its peculiar construction is such
that it serves as legs, as a central support to the segment and cam, and as the
bearings for the pivoting of the body. The supporting frame and foot-stool cast in
one piece avoids a complicated arrangement for producing a separate adjustment of
the said foot-stool, and makes the latter an attachment to the chair. The segment
differs from those heretofore employed in being pivoted near the bottom of the chair
and working through the base, and adapting itself freely to every adjustment.
At
I is a cast iron frame on each side of the chair, which serves as the attachment
for the back and arms to the body of the said chair. At the bottom it has two
projections or flanges u, u, which are screwed to the edge of the square seat.
the top the said frame has a horizontal flange v to which the arm w is screwed, and
at the rear it has a right angled flange x which embraces the edges of the chair-
back and to which it is firmly screwed. The web constituting the body of the
casting may be made in any ornamental form.
This casting forms a convenient and ornamental side to the chair and secures
the seat, the back, and the arm together, avoiding the expensive construction of
ordinary chairs.
One object of this Invention is to enable the parts composing the chair to be
easily separated for storage or shipped for transportation. By removing the screws
b, b, b, the parts composing the base can be separated and removed, and by removing
the screws from the frame D and the side frames I the said parts can also be
removed from the chair. The segment and cam are also easily separated.
If desired, more than one of the notches p may be used on the segment to give
a greater number of adjustments, but in such case the can must be connected to
lock at each adjustment to prevent disconnection.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. In a chair for the use of dentists or hair-dressers, the supporting base or
standard made in two parts fitting together at the centre and united by screws, the

page_text: lower extremities branching outward to form the legs and the upper ends expanding
laterally and provided with solid pivots to form the bearings for the chair-body,
as above set forth and for the purpose specified.
Second. In a chair for the use of dentists or hair-dressers, the frame D with the
footstool D' formed in one piece, and provided with sockets in its upper ends in
combination with the standard A formed in two pieces, and provided with corre-
sponding pivots f, f, the whole arranged as herein described, so that the upper ends
of the divided standard may be inserted between the arms k, k, of the frame and
the pivots may be inserted in the sockets, as and for the purpose specified.
Third. In a chair for the use of dentists or hair-dressers, the combination with
the slotted base A. of the notched and hooked segment, the spring, and the pivoted
lever or cam, as shewn and described and for the purpose specified.
Fourth. In a chair for the use of dentists or hair-dressers, the side frame I con-
structed with the lugs u, u, the flange v, and the right-angled flange x, whereby
the same is adapted to secure the seat, the back, and the arm of the chair together
and to form the side of the chair, as herein shewn and specified.
Fifth. An adjustable chair consisting of the parts constructed and combined as
shown in the accompanying Drawing, and operating as set forth for the purposes
specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Second day of September, in the year of our Lord One
thousand eight hundred and seventy nine.