Improvements in Drawing Boards.
Year: 1889

page_text: Date of Application, 6th Apr., 1889
Complete Specification Left, 6th Jan., 1890-Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Drawing Boards.
CHARLES TINDAL ATKINSON Engineer 7 Westminster Chambers Victoria Street
London S.W. do hereby declare the nature of this invention to be as follows:-
This invention represents a means by which paper tracing cloth or other similar
material, can be stretched tightly, over the surface of a board, and it is accomplished
in the following manner.
Letter A in Fig. 1 is a drawing board, around the outside edges of which, are
arranged 4 hinge pieces marked B in Fig. upon the inside edges of which 'and
running the whole length, is a recess marked B₁ Fig. 3 into which, the tongues C
and can be forced, these tongues are actuated by means of a rigth and left handed
screw marked D in Fig. 4, by means of which the 4 tongues, are made to move at
the same time. In Fig. 4 it will be seen, that the 4 tongues are made to move to and
fro in the following manner. Upon motion being given to the 2 tongues marked C,
by means of the right and left handed screw marked D the movement is transmitted
to the two other tongues marked C', by means of the formation of the plates F¹ which
have two projections shewn in Figs. 4 and 6, these projections work into corre-
sponding slots as shewn at F. Figs. 4 and 6. These projections and slots are placed at
an angle of 45° or thereabouts to the right and left handed screw marked D. A
similar motion can be obtained by having projections at each end of the tongues,
these projections are marked H in Fig. 7 and are placed at an angle of 45° or there-
abouts to the right and left handed screw. These projections work into corresponding
notches or slots in the tongues marked C, so that when a to and fro motion is given
to the tongues marked C it imparts a corresponding motion to the other tongues C¹.
This motion can also be obtained, as shown in Fig. 9 by means of links marked I.
Letter K represents plates for holding the nuts E in their proper place, and are
attached to the tongues C and guided between the guides marked J, in Figs. 7
and 9.
Fig. 2 represents end view of board.
Fig. 8 represents section through Figs. 7 and 9. on line A. B.
Fig. 5 represents section through Fig. 4 on line B, C.
When stretching the paper, the hinge pieces are first turned up, the paper being
then laid over the surface of the board leaving a margin of about 1 inch all round the
edges. The hinge pieces are then turned down. The handle L being turned forces
the tongues and C³ into the recesses and thus tightens the paper.
6th A 1080
CHARLES T. ATKINSON.
COMPLETE
SPECIFICATION.
Improvements in Drawing Boards.
CHARLES TINDAL ATKINSON Westminster Chambers 13 Victoria Street London S.W.
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 consists of a mechanical combination by which paper cloth or other
similar material can be tightened over the surface of a board without damping the
paper etc. and held firmly in its place without using adhesive materials for fastening
the edges of the paper.
Letter A Fig. 1. 2 & 4 is a board around the edges of which are arranged
4 grooved pieces marked B in Fig. 1. 2 3. 4. and 8. These can be either fixed

page_text: or hinged. Figs. 1. 3. 4. 7 and 8 shews them binged and Figs. 8 shews them fixed.
These pieces marked B are grooved upon the inside surface as shewn in accordance
with the Figs. 4 and 8 and marked J but these forms may be varied according to
. circumstances. Into these grooves 4 moveable tongues marked D in Figs. 1 3. 4. 5.
and 8. can be forced. These tongues are actuated by means of a spindle screwed with
a right and left handed thread or with a right or left handed thread only, in which
case a collar can be fixed upon the spindle instead of one of the nuts. The mode by
which the screwed spindle acts upon these tongues is as follows-attached at right
angles to these tongues marked D are + sliding pieces marked D' Figs. 3. 4. 5 and 6.
Upon either of the opposite, pairs of sliding pieces D' are affixed diagonal projections,
the position of which are shown by the dotted lines, letter H. Fig. 3 and also in
section Fig. 3º. A nut marked O in Fig. 3 is let into each of the opposite sliding
pieces into these nuts the right & left handed screwed spindle works, the effect of
which (when the spindle is turned) is either to seperate or bring together the opposite
sliding pieces, to which the nuts are attached, and by means of the diagonal pieces;
the other two opposite sliding pieces are forced out & in, at the same or varying
speed, according to the angle at which the diagonal pieces are placed.
Fig. 6. shows a plan by which the opposite pair of sliding pieces can be worked
seperately by means of a seperate spindle to each pair of sliding pieces. Fig. 5 shows
how the 4 sliding pieces can be actuated by means of 2 nuts marked L working in
opposite directions, having projections fixed to the nuts at right angles or thereabouts
and acting in the sliding pieces marked D' Fig. 5. These nuts are seperated and
drawn together by means of a spindle, screwed with a right and left handed thread.
The spindle revolves in a diagonal line as regards the sliding pieces, and arranged at
such an angle that the two opposite sliding pieces can work at varying speed. Letter E
Figs. 1. 3. 4 and 8. is a frame to which the groove pieces B. are attached. Letters G
Figs. 5. 6 and 7 are handles or keys for actuating the screwed spindles, these could
be either made a fixture or moveable. Letters I Figs. 3. 5 and 6 are guides, guiding
the sliding pieces, so that the edges of the tongues are kept parallel to the board, for
this object all the 4 sliding pieces have to be suitably guided. Letter K Fig. 4 is a
spring to keep the lower side of the groove marked J. firmly pressed upon the tongues,
in order to hold the paper tightly between the two surfaces. This may be substituted
by a stop to keep the grooved piece B in its place.
Letter M Figs. 5 and 6 are collars fixed on the spindle, these prevent the spindles
from moving in a lateral direction. Metal may be substituted for wood when found
desirable.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A mechanical combination, as set forth in the foregoing description; and
drawings, by which paper or other similar material can be stretched tightly over the
surface of a board.
2. A combination of a screwed spindle or spindles with sliding pieces, which spindle
or spindles work in the same plane, with regard to the face of the board.
3. Four grooved pieces marked B either hingedor fixed & arranged around the edges
of the board, or outside it.
CHARLES TINDAL ATKINSON.