Improvements in Convertible Desks for School and other Uses.
Year: 1892

page_text: Date of Application, 14th Apr., 1892
Complete Specification Left, 27th Dec., 1892-Accepted, 4th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Convertible Desks for School and other Uses.
I, JOSIAH JAMES LYNAM, a Director of the Midland Educational Company
imited, of Corporation Street, in the City of Birmingham, School Master, do
ereby declare the nature of this invention to be as follows:-
This invention relates to convertible desks for school and other uses, and has
or its object, securing perfect rigidity, with simplicity of construction.
The locking or securing of the top or slope in three or other number of
positions, is performed by top and bottom locking means, connected with the
bracket fittings, and is so arranged that on the simple lifting of the top or
lope, and the rotation of the same to the desired position about its centre of
notion, and then releasing it, the same falls, and is locked at top and bottom,
hence perfect rigidity.
Ordinary convertible desks have their fittings so arranged that however true
the same may be made, there is always a slight rocking, and want of stability
about them, which is undesirable, whilst in ny invention consequent upon taper
teeth or projections upon one part, fitting into like taper recesses or she-teeth
on the other part, perfect rigidity is attained, besides a locking at two points.
In carrying out my invention in connection with a school desk,
follows:
proceed as
Fitted crosswise upon the top side, and upon the two opposite ends of a shelf
rest, surmounting end standards, which are connected together at their bases,
and to form or seat standards, standing a short distance from the former, by
framings, are upright bearing brackets, cleft or forked in the wider directions at
their upper parts, and in manner that the said branches or sides form cheeks,
between which plate carrying brackets, fitted to the underside ends of the top or
slope, take and turn upon pin centres, taking through the middles of the said
bearing brackets. The lower portions of these said bearing brackets are open,
and each have directed upwardly from the middle of their base parts, a centrally
disposed wedge-shaped tooth whilst the inside top parts of the both sides have
four or other number of teeth or tooth recesses, wherein he- or standing-out teeth,
on the upper part of the carrying bracket, take, as hereinafter described.
The top or slope, which is mounted above the bearing brackets and shelf rest,
has fitted to near the ends of its underside, depending carrying brackets, which
are adapted to work between the checks or sides of the bearing brackets, and
upon the cross pins or centres of them.
Each of these carrying brackets are longitudinally slotted, or are provided with
elongated holes, wherethrough the cross pins, fixed through the bearing brackets,
take, and which elongated holes admit of the top or slope being lifted, and
the teeth of its fittings removed from, or passed into, or between the teeth or
recesses of the fixed and standing brackets of the other part of the desk.
Disposed above and at the two opposite sides of the said carrying bracket,
are three or other number of outstanding and wedge shaped teeth, with the
inwards taper parts directed downwards, and which are adapted to fit within the
she-teeth or recesses formed within the tops of the insides of the cheeks of
the bearing brackets.
Situated upon the lower part of the periphery of these said carrying brackets is
a tooth, or teeth with corresponding spaces between them, which latter are adapted
to take upon the fixed and lower tooth of the said bearing brackets.
Thus we have a convertible desk, composed of a lower fixed portion, with bracket
bearings, having dual locking teeth or tooth recesses, and a top or slope having

page_text: carrying brackets thereunder, which are fitted to, and turn about pins or centres of
the fixed brackets, and have also upper and lower he and she teeth, which lock into
the upper and lower teeth of the fixed framing on the top being released after
being lifted and turned to a desired position.
When a flat table-like top is required, bodily lift the said top, so as to free the
teeth of both parts, then turn the said top, until the same assumes a horizontal
plane, and then when released, the same drops, and is locked in a horizontal
position, when the teeth and spaces of the one part engage within the teeth and
spaces of the other part.
To convert the top into a slope, lift the same as before, and incline it to the
proper angle, when on letting go the teeth or tooth spaces of the one part, fall into
and upon the tooth spaces, and teeth of the other part, hence top and bottom
locking with perfect rigidity.
In a back rest position, the top may be locked, or have stop abutments.
As a modification, teeth may be upon the tops of the bearing brackets instead of
tooth recesses formed within the opposite inside faces of the cheeks.
Dated this 13th day of April 1892.
JOSIAH JAMES LYNAM,
By Hy. Skerrett,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Convertible Desks for School and other Uses.
I, JOSIAH JAMES LYNAM a Director of the Midland Educational Company
Limited of Corporation Street, in the City of Birmingham, School Master, 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 convertible desks for school and other uses, and has for
its object, securing perfect rigidity, with simplicity of construction.
The locking or securing of the top or slope in three or other number of positions,
is performed by top and bottom locking means, connected with the bracket fittings,
and is so arranged that on the simple lifting of the top or slope, and the rotation of
the same to the desired position about its centre of motion, and then releasing it,
the same falls, and is locked at top and bottom, hence perfect rigidity.
Ordinary convertible desks have their fittings so arranged that however true the
same may be made, there is always a slight rocking, and want of stability about
them, which is undesirable; whilst in my invention, consequent upon taper teeth or
projections upon one part, fitting into like taper recesses or she-teeth on the other
part, perfect rigidity is obtained, besides a locking at two points.
In carrying out my invention in connection with a school desk, I proceed as
follows:-
Fitted crosswise upon the top side, and upon the two opposite ends of a shelf rest,
surmounting end standards, which are connected together at their bases, to form
seat standards, standing a short distance from the former, by framings, are upright
bearing brackets, cleft or forked in the wider directions at their upper parts, and
in manner that the said branches or sides form cheeks, between which plate
carrying brackets, fitted to the underside ends of the top or slope take and turn
upon pin centres, taking through the middle of the said bearing brackets.
The lower portions of these said bearing brackets are open, and each have
directed upwardly from the middle of their base parts, a centrally disposed wedge-
shaped tooth, whilst the inside top parts of the both sides have four or other
number of teeth or tooth recesses, wherein he- or standing out teeth on the upper
part of the carrying bracket, take, as hereinafter described.

page_text: The top or slope, which is mounted above the bearing brackets and shelf rest,
has fitted to near the ends of its underside, depending carrying brackets, which are
adapted to work between the cliceks or sides of the bearing brackets, and upon the
cross pins or centres of them.
Each of these carrying brackets are longitudinally slotted or are provided with
elongated boles, wherethrough the cross pins, fixed through the bearing brackets,
take, and which elongated holes admit of the top or slope being lifted, and the
teeth of its fittings removed from, or passed into, or between the teeth or recesses
of the fixed and standing brackets of the other part of the desk.
Disposed above and at the two opposite sides of the said carrying bracket, are
three or other number of outstanding and wedge shaped teeth, with the inward
taper parts directed downwards, and which are adapted to fit within the she-teeth
or recesses formed within the top of the insides of the checks of the bearing
brackets.
Situated upon the lower part of the periphery of these said carrying brackets is
a tooth, or teeth with corresponding spaces between them, which latter are adapted
to take upon the fixed and lower tooth of the said bearing brackets.
Thus we have a convertible desk, composed of a lower fixed portion, with
bracket bearings having dual locking teeth or tooth recesses, and a top or slope
having carrying brackets thereunder, which are fitted-to, and turn about pins or
centres of the fixed brackets, and have also upper and lower he and she teeth,
which lock into the upper and lower teeth of the fixed framing, on the top being
released after being lifted and turned to a desired position.
When a flat table-like' top is required, bodily lift the said top, so as to free the
teeth of both parts, then turn the said top, until the same assumes a horizontal
plane, and then, when released, the same drops, and is locked in a horizontal
position, when the teeth and spaces of the one part engage within the teeth and
spaces of the other part.
To convert the top into a slope, lift the same as before, and incline it to the
proper angle, when ou letting-go, the teeth or tooth spaces of the one part, fall into
and upon the tooth spaces, and teeth of the other part, hence top and bottom
docking with perfect rigidity.
In a back rest position, the top may be locked, or have stop abutments.
As a modification, teeth may be upon the top of the bearing brackets, instead of
tooth recesses formed within the opposite inside faces of the cheeks.
Figure 1 of the accompanying drawings represents in transverse vertical section,
a convertible double-lock school desk, constructed, arranged and provided with
improvements made according to my invention.
The slope, which is a duplex lock, or is locked at top and bottom, or otherwise
at two points removed from each other is shown in the position which it assumes
when in use for writing purposes, whilst the dotted lines represent the position
which the said slope takes when employed as a back-rest.
Figure 2 represents, upon an enlarged scale, the upper part of the said desk and
with the teeth and spaces respectively of the movable part engaging with and
between spaces of the other and fixed part at two positions, viz., top and bottom.
Figure 3 represents a front elevation of the said desk looking rearward by or
from the back.
Figure 4 represents a like section as Figure 2, but with the slope directed
horizontally.
Figure 5 is a vertical section of Figure 4 on the dotted lines A B.
Figure 6 is a like section as Figure 4, but with the teeth and spaces respectively
of the one part, disengaged from the teeth and spaces respectively of the other part
by the lifting of the slope vertically.
The same letters of reference indicate corresponding parts in the several figures
of the drawings.
Supported by standards a, are upright bearing brackets b, carried by a horizontal
shelf bracket c, running the full length of the desk, each of which said bearing

page_text: brackets b, are cleft or forked in their construction, or are respectively composed of
sides, and united by a common base 3, and with the divisional space b,
between the sides 1, 2, of the thickness of the plate of the hanging or depending
slope bracket d, which is mounted and turns upon a pivot e, as a centre, whilst the
extreme lower part of the edge of the said bracket d, has spaces or gaps d', which
engage with a tooth or teeth 6, lignable or in the same vertical plane as the plate
of the bracket d, so that as the slope, which carries brackets d, at its two opposite
ends, is dropped, the gaps d', of the brackets d, take over or upon the teeth, of
the upright brackets b, and as the brackets d, also carry taper and projecting
teeth, upon the two opposite sides of each bracket, and the brackets b, also have
teeth or tooth spaces 66, made within or formed upon the top parts of the inside
presented faces of the sides or cheeks 6, 62, the dropping of the slope with the
teeth and spaces or recesses of the one and movable part coincident with, or in
front of the teeth or spaces of the other and freed part, the said slope becomes
locked at two points, as set forth in Figures 1, 2, 3, 4 and 5.
To admit of the lifting of the slope so that its position can be changed, and the
teeth and gaps or recesses of the one part made to clear, or be removed from the
path of, the teeth and spaces of the other part, the movable brackets d, have long
slots d', within their middle parts, and when the slope is pulled up or lifted, the
ends de come against the fixed pivots or joint centres e, and turn about the same as
bearings.
When the slope is in the position Figure 1, and employed as a back-rest, then
the teeth and spaces respectively do not intergear, whilst the teeth d², lie upon the
peripheries or curved edges of the separated bearer brackets or sides b.
Thus, when the slope is to take an inclined position, as represented in dotted
lines in Figure 1, and assuming that the desk is in the position as shewn in the full
lines; then the lifting or pulling up of the slope f, causes the brackets d, to travel
on the fixed pivots or spindle centres e, and with the teeth d² out of the range of
the gaps or spaces 66, when the said slope can be turned upon the pivot e, and
brought forward to the position, as represented in dotted lines, when the same is
blocked or stopped by the movable and mounted bracket parts carrying the slope
coming against parts of the fixed brackets.
When the slope is required to take a position as in Figure 2, turn the slope
from front to back, when on the teeth d², coming opposite the first three of the
spaces of the gaps 6, and the teeth 6, coming opposite the nearside space of the
gaps d the teeth fall into the said gaps or spaces, and the slope becomes locked at
two points.
The affixing and locking of the slope in a horizontal position is performed alike
unto the locking of the slope in an inclined one, as aforesaid.
Both the fixed and movable brackets are attached in their respective positions to
the woodwork by nuts, pins, bolts or other means.
The standards a, are supported by base framings g, having seat standards h,
surmounted by a seat i.
I wish it to be understood that the slope, may be adjustable in any position as
may be required, by changing the relative positions of the teeth and gaps or spaces
wherein the said teeth take.
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 :-
First In a school desk or other convertible desk, affixing or securing the
slope, or the carrying brackets of the slope in position by a double lock or by top
and bottom locks, or by top and bottom double locks, as set forth.
Secondly-A double-lock slope school or other convertible desk, having fixed
and movable parts, which are secured and affixed in position by teeth and tooth
recesses carried by the movable part or parts engaging within and upon tooth
recesses and both respectively of a fixed or rigid part or parts, as set forth.

page_text: Thirdly-In a school or other convertible desk, mounting the slope upon plate
brackets turning about pivot centres, and working between the branches of
bifurcated brackets, which have tooth recesses and teeth, wherein and wherewith.
teeth and tooth recesses take upon and take into, as described and set forth.
Dated this 23rd day of December 1892.
JOSIAH JAMES LYNAM,
By Henry Skerrett,
6, Livery Street, Birmingham, Agent for Applicant.