IMPROVEMENTS IN ADJUSTABLE STOOLS FOR DENTAL OR OTHER USES
Year: 1884

page_text: I HARRY WILLIAM GREENFIELD of 66 Mortimer Street Cavendish Square in
the County of Middlesex Dentist do hereby declare the nature of my said invention
for IMPROVEMENTS IN ADJUSTABLE STOOLS FOR DENTAL OR OTHER USES to be as
follows:-
My Invention relates to the class of stools or supports adapted for the use of
dentists or others during operations requiring any length of time and slight
movement or change of position by the operator.
The stool or support is formed in the following manner The base plate is
provided with a ball socket joint to which is attached a hollow supporting shaft,
within which is a vertically adjustable spindle which carries the seat or support
The vertical adjustment may be governed by a pawl, a thumb screw, or other
suitable device preferably so arranged as not to interfere with any rotary
movement of the seat.
Lateral movement is permitted by means of the ball socket joint, and such
movement may be governed by a regulated pressure applied at such joint and
further if desired by rubber or other elastic packing surrounding the supporting
shaft and bearing against the upper or adjustable portion of the socket joint or
directly against the base plate as the case may be Or in lieu of the rubber
packing, elastic bands may be attached to the supporting shaft and base plate
respectively.
It will be apparent that should the operator desire to move to the right or to
the left, or backwards or forwards, he will be enabled to do so without any further
effort on his part than that of mere pressure in the desired direction.

page_text: I HARRY WILLIAM GREENFIELD of 66 Mortimer Street Cavendish Square in
the County of Middlesex Dentist do hereby declare the nature of my said invention
for IMPROVEMENTS IN ADJUSTABLE STOOLS FOR DENTAL OR OTHER USES and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My Invention relates to the class of stools or supports adapted for the use of
dentists or others during operations requiring any length of time, and slight
movement or change of position by the operator. The stool or support is formed
in the following manner, reference being made to the accompanying drawing which
forms part of this specification and in which the adjustable stool is represented
almost entirely in sectional elevation.
The base plate A is provided with a socket or cup A¹ in which rests a ball B
which is attached to a hollow supporting shaft C within which is a vertically
adjustable spindle D which carries the seat or support E.
The vertical adjustment is shown as being regulated by a pawl F (kept in
position by spring f) the end of which passes through a slot in shaft C aud
engages with the notches on spindle D, said spindle being kept from revolving by
means of a screw pin g which passes into a vertical slot g¹ in said spindle, which it
prevents from leaving supporting shaft C. Instead of the pawl as described, the
adjustment may be governed by a thumb screw, or other suitable device preferably
so arranged as not to interfere with any rotary movement of the scat.
Lateral movement is permitted by means of the ball socket joint A' B, and such
movement may be governed by a regulated pressure applied at such joint, by
means of screw bearing H which when screwed down, bears upon the ball B and
tends to keep the seat in whatever position it may be placed, and further if desired
by means of a rubber or other elastic packing I surrounding the supporting
shaft C, and bearing against the upper or adjustable screw portion H of the socket
joint, or directly against the base plate A, if part H passes below the level or in
lieu of the rubber packing, elastic bands may be attached to the supporting shaft C
and base plate A respectively.
The seat E is secured to the spindle D by means of a plate K provided with a
boss which rests upon a ring or shoulder L on spindle D, the upper end of said
spindle passes through the boss and is secured by a nut while beneath the ring or
shoulder L, or upon the top of hollow shaft C is placed a rubber ring or other
packing M which will prevent a noisy concussion should the seat be allowed to
drop down on to shaft C. It will be apparent that should the operator desire to
move to the right or to the left, or backwards or forwards, he will be enabled to do
so without any further. effort on his part than that of mere pressure in the desired
direction while seat E may be raised or lowered as desired.

page_text: 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
1. In adjustable stools, the combination with the supporting shaft and spindle, of
a ball socket joint adapted to operate substantially as set forth.
2. The general combination of parts forming an adjustable stool, the seat of
which is capable of being raised, lowered and revolved, while the carrying shaft
attached to a ball socket joint is capable of side inclination, substantially as
described and as illustrated in the accompanying drawing.
PHILIP M. JUSTICE,
Applicant's Agent