Improvements in or relating to School-desks and Seats.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in or relating to School-desks and Seats.
A communication by the HYGIENIC SCHOOL FURNITURE Co., of 150, Nassau
Street, New York, in the County and State of New York, United States of
America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6, Bank Street, Manchester,
both in the County of Lancaster and 323 High Holborn, in the County of Middlesex,
Civil Engineer, 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:-
This invention relates to school furniture, and has for its object to simplify,
strengthen, and cheapen the construction of the mechanism for effecting the vertical
adjustment of the desk-top or chair-seat (as the case may be) and keeping the same
in its adjusted position. To this end, the improvement consists in the detailed
construction and combination of parts of the mechanism, as will be hereinafter more
fully described and claimed.
Figure 1, is a sectional view on a vertical plane of a school desk of this improved
construction.
Figure 2 is a similar view of the improvement as applied to a chair, but
showing certain modifications in the constructions and arrangement of the operating
parts.
Figure 3 is a cross section through the stationary tubular standard and movable
support, on line y-y in Figure 2.
Figure 4 shows the improved construction in a modified form, and is a sectional
view, on a vertical plane, of a school desk.
Figure 5 is a transverse sectional view on line x- in Figure 4.
Like letters of reference denote corresponding parts in all the figures.
Referring to the drawings, the letter A designates the desk-top, A¹ the chair-seat,
and B the stationary tubular upright or standard used with both, which is screwed
or bolted to the floor in the usual manner. To the under side of the desk or seat is
fastened the adjustable bearing or support C, which slides loosely in the socket
of the tubular fixed standard B.
This adjustable support or bar has on one side a longitudinal groove or channel D,
adapted to receive the inner ends of the binding screws I and I', said screws working
in the bearings i and i, in the upper part of the tubular standard B. These
binding-screws have squared heads, so that they may be turned with a key or
wrench when it is desired either to release the sliding standard C, or, by turning
the screws in the opposite direction, to fasten the same at its proper elevation
relatively to the standard.
In order to hold or maintain the standard C in its adjusted position within the
tubular standard B, during the operation of tightening down the binding-screws, I
and I, various means are employed, all of which have for their object to produce a
strong friction.
In the form Figures 1 and 2, there are cut or cast on the side opposite the
groove Da vertical row of notches forming small teeth, E, which do not project.
beyond the solid parts of the bar. Fastened in the upper open end of the standard B
is a catch F, the inner end of which projects into the hollow interior of the
standard, so as to engage, under certain conditions, with the teeth of the vertically
movable bar or support C. This catch or retaining pawl F may be constructed
and applied in various ways: for example, it may be simply a short flat piece of
tempered steel fastened in the open mouth or top of the tubular standard by a

page_text: screw G, as illustrated in Figure 1 ; or it may be a steel screw screwed into a
threaded hole in the standard and furnished with a small nut-lock, or washer g, to
hold it firmly in place as shown in Figures 2 and 3. This last named construction
affords an easy means for "taking up wear on the inner end of the retaining pawl
by permitting of its adjustment as occasion may require.
"
Within the tubular standard, some distance below this retaining pawl and
on the opposite side thereof, a spring, or a spring bearing H may be placed,
which bears or presses with its free end against the slotted side of the movable
support C.
This device may be either in the nature of a simple leaf-spring, as shown in
Figure 1, with one end fastened, by a screw h, in the standard, and its free end
pressing against the sliding bar; or it may be a block or bearing, as illustrated in
Figure 2, having a coiled spring around its stem which presses it against bar C on
the side opposite to its toothed part. But this spring, in any of its forms, is not a
necessary adjunct of, or condition to, the successful operation of this invention, and
may be dispensed with, if desired. Moreover, this spring device may be used
independent of a notched bar C and retaining pawl F, and can be used in
combination with a vertically adjustable smooth bar C, (i.e. a bar without notches).
The upper part of the stationary standard B is reinforced so as to form bearings, i,
of sufficient thickness and strength for the binding-screws I and I¹, the inner ends of
which project into and can be made to bear or bind against the bottom of the
longitudinal groove D. These screws form the essential means by which the desk-top
or chair-seat (as the case may be) is permanently fasteued, in its adjusted position,
upon the fixed standard B; the notches and teeth in bar C forming, in conjunction
with the retaining-pawl F, merely a temporary hold or fastening, (contributing,
however, also to the permanent fastening) for the desk-top and its depending bar
while these are being adjusted for a permanent position, vertically.
In the modified form, Figures 4 and 5, a spring is employed, so constructed and
arranged that it will clamp or press against the sliding bar or standard, C, so as
to hold the same in position by friction. The bar C may be notched as in
Figures 1 and 2, or may be smooth as shown in Figure 4, then this spring is to
hold the desk-top, by friction alone, in its properly adjusted position until the
binding-screws have been turned down so as to bind against the sliding standard
and thereby permanently fasten the same in its socket. This ring consists of a
steel collar E', located in an annular recess F¹ in the upper part of the tubular
standard B; and is open on one side clamping the cylindrical stem C with sufficient
friction to support it and the superimposed desk body. This spring will abut
against the upper and lower walls of said recess as the stem is raised and lowered, so
that its movement will be checked.
By this means the ring will hold the stem in any position to which it is adjusted
until it is permanently secured in place by means of the set screws.
The construction of this device, having been described, the method or manner of
operating it will now be described, which is briefly as follows:
In this
If it is desired to raise the desk-top or chair-seat (as the case may be), the binding
screws I and I are first loosened, by a wrench or key applied to their squared heads,
so that the grooved bar C will have some play or lateral motion in its socket. By
now taking hold of the desk at or near its inner end (i.e. the end next to the seat)
it will be tilted slightly forward, as indicated in dotted lines in Figure 1, so as to
disengage or release the series of teeth E from the inner end of pawl F.
position, the desk-top (or chair-seat) may be easily lifted and raised to its desired
elevation, and, by now letting go of the same, it will, owing to the preponderance
of weight on the lifted side, tip or tilt back into the position shown in full lines, in
which position the teeth E will act somewhat like a file, and will produce a very
strong friction by engaging and interlocking with the projecting inner end of the
catch or retaining-pawl F, or with the upper edge of the bore in the socket, or with
the edge of the clamping ring E' when the same is used in combination with a
notched bar or standard C.

page_text: When the clamping spring E' is used in combination with a smooth bar, as repre-
sented in Figures 4 and 5, the grooved bar C may easily be moved up and down,
after having loosened the set screws I and I'. After it has been properly adjusted,
as regards elevation, the friction of the spring within the socket will be sufficient to
maintain it in its adjusted position.
By then tightening-up the binding screws I and I', the movable supporting bar C,
and with it the desk-top or chair-seat, will be fastened permanently (for the time
being) in its adjusted position.
To lower the desk-top or chair-seat, this operation is simply reversed. It will be
seen that, after the binding screws have been loosened, the movable stem or support C
has sufficient play to permit of its being lowered.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is:
1) The combination of the tubular standard, the vertically movable support having
loose lateral play therein and provided with a row of teeth on one side, the retaining
pawl adapted to engage with said teeth, and the binding screws in vertical alignment
with each other, and their inner ends bearing against said support, substantially as
and for the purpose specified.
2) The combination of the stationary tubular standard, the vertically movable
support having loose lateral play therein and provided with a row of teeth on one
side, and a longitudinal groove on the side opposite, the retaining pawl adapted to
engage said teeth, the spring secured to the standard and bearing against the
support, and the binding screws in vertical alignment with each other, their inner
ends bearing against said support and the lower screw substantially as and for the
purpose specified.
3) The combination of the stationary standard, formed with an annular recess in
its interior, the vertically movable support sliding loosely in said standard; a friction
or clamping spring consisting of a split ring located within the annular recess in the
standard and adapted to press or bear against the movable support; and the binding
screws substantially as set forth.
Dated this 20th day of Ma. 1002
WM. P. THOMPSON & Co.,
Agents for the Applicant.