Improvements in Stop-joints or Hinges for School-desks and other Furniture.
Year: 1896

page_text: Improvements in Stop-joints or Hinges for School-desks and other
Furniture.
I, JOSIAH JAMES LYNAM, of 46 Lee Crescent in the City of Birmingham, School
Master, do hereby declare the nature of this invention to be as follows:-
This invention relates to stop-joints or hinges for desks, seats and other articles
of furniture convertible to various uses and employed in schools, churches or the
like, such for instance as school desks, which admit of being converted into seats
with back rests by turning the desk parts upon hinges or joints into approximately
a vertical plane, and has for its object, a concealed joint or hinge so constructed as
to obviate any liability of the same to pinch the fingers of children or others when
changing a desk or the like from one position to another.
One form of the improved joint consists of two halves or cheeks one of which is
carried by a fixed arm or standard of the desk, and the other by the movable arm
said cheeks working face to face and being connected together by a cross pin or
pivot. The face of each of these cheeks is formed with a concentric groove, cut at
any desired distance from the centre and extending more or less around the cheek
according as to the amount of tip or turn which the joint is to admit of, such, for
example, as through three quarters of a circle. The part of the cheek between the
ends of the groove carries a concentric block, projection or tongue, curved to the
same radius as the groove, and comprehending together with the groove a complete
circle. Thus, when the cheeks are placed face to face, in their position of use, the
tongues or projections of each cheek respectively take into the opposed grooves of
the opposite cheeks, and the extent of the turning motion of the one cheek within
the other is limited by the ends of the tongues abutting against one another.
According to another form of these improvements, the cheeks or halves of the
joint are mounted respectively upon a fixed and a movable member and connected
together by a pivot pin as before, with a hub or boss on the face of the one having
a dovetail or other shaped stop projecting from its periphery and with the boss
and stop taking respectively into a circular and a fan-shaped combined sinking
made in the opposed face of the other half or cheek of the joint. Thus the circular
boss works in the circular part of the sinking whilst the wedge-shaped stop works
and describes a radius of about 45 degrees in the quadrant-shaped part of the
recess, whose ends form abutments for limiting the movement of the joint.
In both of the aforesaid forms of joint, the edges of the cheeks are overhung by
deep flanges or outstanding parts recessed to a curve whose radius is struck from
the same centre as the cheeks and respectively cast or forged all in a piece with the
fixed standard and its cheek and the movable arm and its cheek.
In operation, these overhanging edges are prevented from coming together by
the internal ston.

page_text: The circular boss on the one cheek, as described in the second form of joint,
is slightly coned so as to fit truly into the corresponding sinking in the other cheek.
Dated this 11th day of November 1896.
JOSIAH JAMES LYNAM.
By Henry Skerrett,
Agent for Applicant.
Improvements in Stop-joints or Hinges for School-desks and other
Furniture.
I, JOSIAH JAMES LYNAM, of 46 Lee Crescent 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 stop-joints or hinges for desks, seats and other articles
of furniture convertible to various uses and employed in schools, churches or the
like, such for instance as school desks, which admit of being converted into seats
with back rests by turning the desk parts upon hinges or joints into approximately
a vertical plane, and has for its object, a concealed joint or hinge so constructed as
to obviate any liability of the same to pinch the fingers of children or others when
changing desk or the like from one position to another.
Figure 1 of the accompanying drawing represents my improvements applied to
a turn-up school desk and turn-up seat, with back rest.
Figure 2 represents an elevation of the inside face of the movable half or cheek
of the joint.
Figure 3 is a like view of the fixed movable half of the same carried by the
standard.
Figure 4 is a back elevation of the joint and
Figure 5 a vertical section thereof upon the dotted line, Figure 4.
Figure is a vertical section upon the dotted line, Figure 5.
Figure 7 is a vertical section upon the dotted line 3, Figure 2, and
Figure 8 is a vertical section upon the dotted line, Figure 3.
The same letters of reference indicate corresponding parts in the several figures
of the drawing.
The improved joint, as illustrated in the drawing consists of two halves or
cheeks a and b, the former of which is carried by a fixed arm or standard c, of the
seat or desk, and the other by the movable arin d, thereof, said cheeks working
face to face and being connected together by a cross pin or pivot e.
The face a¹,
of the cheek a, is formed with a concentric groove a, cut at a distance from the
centre and extending more or less around the cheek according as to the amount of
tip or turn which the joint is to admit of, such, for example, and as shown in the
drawings, through about two thirds of a circle. The part of the cheek between
the ends a³, of the groove carries a concentric block, projection or tongue a, curved
to the same radius as the groove, and comprehending together with it, a complete
circle. The opposed face b1, of the other cheek b, is similarly formed with a
groove, and projecting block, tongue or rib 64, so that when the said cheeks are
placed face to face, in their position of use, the tongues or projections a, b, of
cach cheek respectively take into the opposed grooves a, b, of the opposite cheeks,
and the extent of the turning motion of one cheek upon the other is limited by
the ends a, b, of the tongues respectively abutting against the ends a³, 63, of the
grooves, which are continuous with the said ends of the tongues.

page_text: The desk f, and seat g, shown in Figure 1, are coupled together by a bed-
board h.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
First. A stop joint or hinge for school desks and seats and other turn-up, turn-
down and convertible furniture, consisting of two checks or halves preferably con-
nected by a cross pin or pivot, and with the opposed or presented faces of the same
each having a channel, groove, clearance, or sinking, and a tongue, so arranged
that the tongue of each cheek takes into the groove, sinking or clearance of the
other cheek, thereby forming a concealed joint having no naked shoulders or
parts liable to pinch the fingers, substantially as described and set forth.
Secondly. The general construction, arrangement and combination of the parts
of stop-joints or hinges for school desks, seats and the like, substantially as
described and set forth.
Dated this 27th day of July 1897
JOSIAH JAMES LYNAM.
By Henry Skerrett,
24 Temple Row, Birmingham, Agent for Applicant.