Year: 1888

page_text: Date of Application, 16th May, 1888
Complete Specification Left, 15th Feb., 1889
Complete Specification Accepted, 6th Apr., 1889
I HENRY DOWN of Sheepcote Street Birmingham in the County of Warwick
Contractor do hereby declare the nature of this invention to be as follows:-
These improvements are an improved method of raising and lowering the seat and
altering the position and angle of the back and also in adjusting the head rest and
consists in fixing the seat of the chair to, rods or bars sliding in grooves or telescopic
slides in the chair frame or support of the seat.
To the underside of the seat is fixed by a hinged joint a rod or bar wormed with a
screw thread upon which works a toothed pinion or bevilled toothed wheel which takes
into another toothed pinion upon a rod which rod projects from the side of the chair
so as to allow of a handle being keyed thereon.
The turning of this handle will then enable the seat to be raised or lowered at will.
The back of the chair being hinged to the seat and resting against a back rail of the
chair will be altered in its angle according to the position of the seat.
Instead of the seat itself being supported in the grooves as before named a frame
acting as a carrier may be so placed and the seat made to slide in grooves upon the
carrier so that the seat may be drawn forward at will, thus still further altering the
relative angle of the back and seat.
The improvement in the head rest consists in forming it as a reel padded all round
and hung out of its centre upon pivots so as to give it an eccentric motion when
turning by which means a great variety of positions are given to it relative to the
positions of the back and seat.
A circular rack with bolt holes therein is fixed at one end of the head rest with a
bolt on the chair back to shoot into the racks and thus fix the head rest in any desired
position.
PAYNE & TALBOT,
7, Cherry Street, Birmingham,
Agents for the Applicant.

page_text: I HENRY DOWN of Sheepcote Street Birmingham in the County of Warwick
Contractor 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, reference being had to the accompanying drawings and to the
letters and figures marked thereon:―
These improvements are an improved method of raising and lowering the seat and
altering the position and angle of the back and also in adjusting the head rest and
consists in fixing the seat of the chair to rods or bars sliding in grooves or telescopic
slides in the chair frame or support of the seat.
To the underside of the seat is fixed by a hinged joint a rod or bar worned with a
screw thread upon which works a toothed pinion or bevilled toothed wheel which takes
into another toothed pinion upon a rod which rod projects, from the side of the chair
so as to allow of a handle being keyed thereon.
The turning of this handle will then enable the seat to be raised or lowered at will.
The back of the chair being binged to the seat and resting against a back rail of the
chair frame will be altered in its angle according to the position of the seat.
Instead of the seat itself being supported in the grooves as before named a frame
acting as a carrier may be so placed and the seat made to slide in grooves upon the
carrier so that the seat may be drawn forward at will thus still further altering the
relative angle of the back and seat.
The improvement in the head rest consists in forming it as a reel padded all round
and hung out of its centre upon pivots so as to give it an eccentric motion when
turning by which means a great variety of positions are given to it relative to the
positions of the back and seat, a circular rack with bolt holes therein is fixed at one end
of the head rest with a bolt on the chair back to shoot into the rack and thus fix the
head rest in any desired position.
Referring to the Drawings, Fig. 1 is a perspective back view of a chair shewing the
various parts to which my invention applies. Fig. 2 is a sectional view of the same
and Fig. 3 a detail of a modification of the screw principle. (a) is the rod or bar
wormed with a screw thread and carrying upon it the toothed pinion (b) which
toothed pinion (b) takes into another toothed pinion (c) upon the rod (d) so that
turning the rod (d) by means of the handle or key (e) will raise or lower the rod (a)
which is fixed to the underside of the seat support or carrier () this seat support ()
has at each end the blocks (g) which travel in the grooves (h) so that the raising
or lowering of the rod (a) as before described will cause it to carry with it the seat
support or carrier (f).
To the seat (i) is hinged the back () which is supported by the back rail (k) of the
framework (1) of the chair. When the seat (i) is raised as before described its slope or
angle is not varied but in consequence of its position relative to the back rail (k) the
angle of the back (j) leaning against the back rail (k) is altered.

page_text: The rod (d) is shewn in Fig. 1 passing between the front and back supports of the
chair (m) and (m) but it may be arranged as shewn in Fig. 3 to work at an angle and
be supported at the back of the chair support (m).
To further vary the angle of the back to the seat (i) scrow threaded bar (n) may be
placed underneath the seat (i) which seat (i) is grooved to travel upon the carrier (f)
so that the turning of the screw threaded bar (2) will vary the position of the seat (i)
upon the carrier (f) and thus alter the position of the back (7) as indicated in dotted
lines Fig. 2.
The height of the back (j) may also be varied by forming the back (1) of two parts
as () and () as shown in Fig. 2 by forming grooves in the lower part from (c) to (a)
and (y) to (y) Fig. 1. So that the upper portion (5) Fig. 2 may be raised leaving the
lower portion (1) Fig. 2 stationary. The raised portion is kept in position by any
suitable form of rack (o) and catch at (t) Fig. 2 by which it may be held or it may
be raised by a screw threaded bar as in the case of the other moveable parts.
(p) is the head rest formed as a padded reel and hung out of its centre at (9) so as
to allow of it being adjusted in a variety of positions (r) is the rack containing a
number of bolt holes so that when the rest is turned to the required position a bolt (s)
which may be a spring or self acting bolt will let into one of the holes and hold it
firmly.
I wish it to be understood that I do not confine myself to the precise form of the
chair itself or of the form of the details of the mechanical parts as illustrated by the
drawings and that although I call it a dental chair I desire to apply it to other purposes
such for instance as for hairdressers use.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
The construction of a chair for dental and other purposes substantially as herein sot
forth and specified whereby the relative angles of the various parts of the chair can
readily be altered and adjusted.
PAYNE & TALBOT,
7, Cherry Street, Birmingham,
Agents for the Applicant.