Year: 1886

page_text: I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Engineer, do hereby declare the nature of the invention (a communication from
William Stahlschmidt manufacturer and Jacob Herbert Mickler, Mechanic both of
Preston, Canada), and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The objects of the invention are first that the weight of the pupil shall not have
any tendency to tilt or move the seat; secondly to so form a stop-hinge that there
shall be no strain on its pivot-bolt; and thirdly to so form the joint of the folding-
desk that it will not warp or get out of truth; and it consists, first in so forming
the frame supporting the seat that when the pupil is seated the centre of gravity
shall fall well within the base of the frame supporting the said seat; secondly in
forming an annular flange on one half of the hinge designed to fit over a
boss formed on the other half and surrounding the pivot-bolt, a projecting lug
being formed on the outside of the annular flange to butt against a shoulder or
shoulders formed within the recess in which the annular flange fits; and thirdly in
forming a tongue and groove on the edges of the hinge and stationary portions of
the desk which tongue and groove will fit into each other when the desk is opened
to write upon.
Figure 1 is a perspective view representing a pupil sitting upon this improved
seat and reading from a book carried in a desk in front of him.
Figure 2 is an enlarged detail representing one half of the hinge.
Figure 3 is a similar view representing the other half of the hinge.
Figure 4 is an enlarged sectional detail, showing the tongue and groove joint
employed between the hinge and stationary portion of the desk.
It will be noticed that the leg A of the frame which supports the seat and desk,
is shaped so as to extend in front of the point which is the centre of gravity when
the pupil is seated as indicated in Figure 1. By thus forming the frame the weight
of the pupil will hold the desk in a steady position so that there will be no strain
upon the screws which secure the desk to the floor, and moreover the seating of the
pupil will not shake the desk to the same extent it would were the centre of
gravity outside of the supporting leg which is the practice in desks as made prior
to this invention.
The stop-hinge illustrated in Figures 2 and 3 is a detail of the hinge employed
in connecting the folding portion B of the desk to the stationary portion C of the

page_text: same but of course the same style of hinge may be used for connecting the seat D
to the frame. This hinge it will be seen consists of an annular flange a formed on
the arm E which supports the desk B. This flange is designed to fit over a hub F
formed round the bolt hole b through which the pivot bolt passes. The flange a is
made an easy fit upon the hub F and it is intended that the entire weight and
strain shall be borne by the hub and flange mentioned, so as to entirely relieve the
pivot-bolt which passes through the holes b made in both the arms E. and G,
consequently all that the said bolt is required to do is to hold the two arms
together.
h is a lug formed in the outside of the annular flange a which lug is designed to
butt against either one or other of the shoulders i made in the recess j which is
formed in the arm G as indicated.
When the desk or seat provided with this improved hinge is extended out the
lugh butts against one of the shoulders ; when folded the said lug butts against
the other shoulder, so that the entire strain is carried by the lug and shoulder
mentioned.
On reference to Figure 4 it will be noticed that a groove d is made on the edge
of the portion of the desk marked C and that a tongue e is formed on the edge of
the portion of the desk marked B which tongue enters the groove when the desk is
extended as represented in the rear desk of Figure 1. By thus providing a tongue
and groove joint as indicated the joint will always remain a perfect one and the
desk will always be perfectly smooth on top.
On the bottom of the desk B a ledge f is formed to support a book. An elastic
band g stretched between and attached to the two arms G is provided for the
purpose of holding the leaves of the book H open, so that the student or pupil has
his hands free while studying.
The ledge f, of course is not claimed nor indeed any single element in the inven-
tion as it is merely the combinations of the particular parts specified which produce
the desired results. It should also be mentioned that in the construction of the
seat it is absolutely necessary that the centre of gravity shall be sufficiently within
the base formed between the legs so that the seating of the pupil shall have no
tendency to tilt the seat which desirable effect would not be attained were the
centre of gravity merely just within the leg A.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated
to me by my foreign correspondents, I declare that what I claim is :—
1. In a school desk the combination of a seat D, hinged to a frame provided
with a leg A extending outwardly so that the centre of gravity when the pupil is
teated shall fall inside of the leg A substantially as and for the purpose specified.
2. A stop hinge composed of an annular flange fitted over the hub f in combina-
tion with the lug h formed on the annular flange a and designed to butt against the
shoulders substantially as and for the purpose specified.
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3. The folding-desk B connected to the arms E which are pivoted on the arms G
provided with a stop hinge as specified, in combination with a tongue e and groove d
arranged substantially as and for the purpose specified.
4. The folding desk B supported on the arms E and provided with a ledge fin
combination with an elastic band g arranged substantially as and for the purpose
specified.