IMPROVEMENTS IN ADJUST- ABLE SCHOOL DESKS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER ARTICLES OF FURNITURE
Year: 1877

page_text: LETTERS PATENT to William Cowper Pellatt, of Aylesbury Street, Clerkenwell,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN ADJUST-
ABLE SCHOOL DESKS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER
ARTICLES OF FURNITURE."
Sealed the 23rd November 1877, and dated the 5th June 1877.
PROVISIONAL SPECIFICATION left by the said William Cowper Pellatt
at the Office of the Commissioners of Patents on the 5th June 1877.
66
WILLIAM COWPEr Pellatt, of Aylesbury Street, Clerkenwell, in the County
of Middlesex. IMPROVEMENTS IN ADJUSTABLE SCHOOL DESKS, WHICH IMPROVE-
MENTS ARE ALSO APPLICABLE TO OTHER ARTICLES OF FURNITURE."
The Invention has for its object improvements in adjustable school desks, which
improvements are also applicable to other articles of furniture.
În adjustable school desks the standard or frame is formed of two principal parts,
namely, the main upright and the plate upon which the top or desk is fixed.
According to my Invention the main upright at its top is of curved or circular
form, of convenient diameter and thickness, having an inclined or bevilled edge, and
a central point of axis from which the curve or circle is struck. The top plate has
two arins projecting downwards at right angles thereto, one of which is cast upon
the plate, and the other of which takes into or hinges in a socket or slot cast or
formed in the top plate, or it may be otherwise adjustably connected with the top
plate. These arms pass on either side of the curved or circular top of the main
upright and have a bolt passed through their extremities and the point of axis on
the main upright, thus allowing the top plate to revolve round such bolt when
desired within the limits of the curve or circle. This bolt is threaded at one end to.
receive a hand nut. ·
:
The rigid arm has its upper inner part, near its junction with the top plate,
bevilled or inclined to the same angle as the bevilled edge of the main upright, and
the loose arm has a flat-headed projection or stud formed at its upper inner part,
which, when the hand nut is operated to force the moveable arm towards the fixed
ärm, presses against the main upright to keep it square with the top plate, and

page_text: thereby prevent the parts being unduly strained or twisted. It will thus be seen
that the leverage exerted on the main upright through the hand nut and the move-
able arm and stud is so great that the desk top may be fixed at any desired angle
within the limits of the curve or circle at the top of the main upright, even by the
force of a child's fingers applied to the hand nut; and by reason of the tendency
which the bevilled surface of the fixed arm has to ride up upon the bevilled edge of
the main upright when the hand nut is screwed up, not only is the desk top firmly
fixed in any desired position, but the bolt is drawn to the upper surface of the hole
- or central point of axis in the main upright through which it passes, and thus binds
all the parts together so firmly that the shake or vibration which is common to all
other adjustable desks is obviated.
It will be understood from the foregoing description of my Invention, that with
slight modifications it can be easily adapted to many articles of furniture other than
school desks, and such as folding or chair bedsteads, lounge chairs with adjustable
backs, and reading desks, and other articles of a like description.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Cowper Pellatt in the Great Seal Patent Office on the
5th December 1877.
WILLIAM COWPER PELLATT, of Aylesbury Street, Clerkenwell, in the County
of Middlesex. 'IMPROVEMENTS IN ADJUSTABLE SCHOOL DESKS, WHICH IMPROVE-
MENTS ARE ALSO APPLICABLE TO OTHER ARTICLES OF FURNITURE."
The Invention has for its object improvements in adjustable school desks, which
improvements are also applicable to other articles of furniture.
In adjustable school desks the standard or frame is formed of two principal parts,
namely, the main upright and the plate upon which the top or desk is fixed.
According to my Invention, the main upright at its top is of curved or circular
form, of convenient diameter and thickness, having an inclined or bevilled edge and
a central point of axis from which the curve or circle is struck. The top plate has two
arms projecting downwards, at right angles thereto, one of which is cast upon the
plate, and the other of which takes into or hinges in a socket or slot cast or formed
in the top plate; or it may be otherwise adjustably connected with the top plate.
These arms pass on either side of the curved or circular top of the main upright,
and have a bolt passed through their extremities, and the point of axis on the main
upright thus allowing the top plate to revolve round such bolt when desired within
the limits of the curve or circle. This bolt is threaded at one end to receive a
hand nut.
The rigid arm has its upper inner part, near its junction with the top plate,
bevilled or inclined to the same angle as the bevilled edge of the main upright, and
the loose arm has a flat-headed projection or stud formed at its upper inner part
which, when the hand nut is operated to force the moveable arm towards the fixed
arm, presses against the main upright to keep it square with the top plate, and
thereby prevent the parts being unduly strained or twisted. It will thus be seen
that the leverage exerted on the main upright through the hand nut and the move-
able arm and stud is so great that the desk top may be fixed at any desired anglé

page_text: within the limits of the curve or circle at the top of the main upright even by the
force of a child's fingers applied to the hand nut; and by reason of the tendency
which the bevilled surface of the fixed arm has to ride up upon the bevilled edge of
the main upright when the hand nut is screwed up, not only is the desk top firmly
fixed in any desired position, but the bolt is drawn to the upper surface of the hole
or central point of axis in the main upright through which it passes, and thus binds
all the parts together so firmly that the shake or vibration which is common to all
other adjustable desks is obviated.
"
It will be understood from the foregoing description of my Invention that with
slight modifications it can be easily adapted to many articles of furniture other than
school desks, and such as folding or chair bedsteads, lounge chairs with adjustable
backs, and reading desks, and other articles of a like description.
"
And in order that my said Invention may be more clearly understood and readily
carried into effect, I will proceed, aided by the accompanying Drawings, more
Figure 1 is an end elevation of an adjustable school desk with my improvements
applied thereto; Figure 2 is a side elevation, and Figure 3 is an end elevation of
parts thereof drawn to an enlarged scale; Figure 4 is a sectional under side view of
the same on the line 1, 1, of Figure 3, and Figure 5 is a sectional under side view
on the line 2, 2, of Figure 3.
A is one of the standards or frames, and B is the adjustable desk top. The
standard A is formed in two principal parts, namely, the main upright a and the
plate a¹, upon which the top or desk B is fixed.
According to my Invention the main upright a at its top a³ is of curved or circular
form, of convenient diameter and thickness, having an inclined or bevilled edge a³
and a central point of axis from which the curve or circle is struck. The top
plate a¹ has two arms a, a, projecting downwards at or about right angles thereto,
one of which (a), is cast upon the plate a', and the other of which (a³) takes into
or hinges in a socket or slot a cast or formed in the top plate a¹, or it may be other-
wise adjustably connected with the top plate a. These arms a, a, pass on either
side of the curved or circular top of the main upright, and have a bolt 6 passed
through holes formed in their extremities and the point of axis on the main
upright a, thus allowing the top plate a¹ to revolve round such bolt b when desired
within the limits of the curve or circle. This bolt b is threaded at one end to
receive a hand nut c.
The rigid arm a has its upper inner part a near its junction with the top plate a¹
bevilled or inclined to the same, or nearly the same angle, as the bevilled edge a³ of
the main upright a, and the loose arm a³ has a flat-headed projection or stud a³
formed at its upper inner part, which, when the hand nut c is operated to force the
moveable arm as towards the fixed arm at, presses against the main upright to
keep it square with the top plate a¹, and thereby prevent the parts being unduly
strained or twisted. It will thus be seen that the leverage exerted on the main
upright a through the hand nut c, and the moveable arm a³ and stud a³ is so great
that the desk top B may be fixed at any desired angle within the limits of the curve
or circle at the top of the main upright a even by the force of a child's fingers applied
to the hand nut c, and by reason of the tendency which the bevilled surface of the
fixed arm at has to ride up upon the bevilled edge as of the main upright a when the
hand nut c is screwed up, not only is the desk top B firmly fixed in any desired
position but the bolt bis drawn to the upper surface of the hole or central point of
axis in the main upright A, through which it passes, and thus binds all the parts
together so firmly that the shake or vibration which is common to all other adjust-
able desks is obviated.
At Figures 6 and 7 I have shown respectively a side elevation and an end eleva-
tion of parts of a chair with an adjustable back provided with my improvements in

page_text: a form somewhat modified from that above described; C is the back of the chair,
and D is the seat. These two parts are connected together adjustably by means of
parts similar to those above described, similar parts being marked with similar
letters of reference to those above employed.
It will be readily understood from the foregoing description of my Invention that
with slight modifications it can be easily adapted to many articles of furniture other
than those above described, and such as folding or chair bedsteads, reading desks,
and other articles of a like description.
Having thus described the nature of my said Invention and the mode in
which I carry the same into effect, I would have it understood that what I'
claim is, the peculiar arrangement and combination of parts applicable to school
desks and other articles of furniture, substantially as and for the purpose herein
shown and described.
In witness whereof, I, the said William Cowper Pellatt, have hereunto
set my hand and seal, this Fifth day of December, in the year of our
Lord One thousand eight hundred and seventy-seven.
W. C. PELLATT
(1.8)