Improvements relating to Drawing Boards and in Ruling Attachments therefor.
Year: 1897

page_text: Date of Application, 16th Aug., 1897-Accepted, 26th Mar.,
1898
COMPLETE SPECIFICATION.
Improvements relating to Drawing Boards and in Ruling
Attachments therefor.
I, ALEXANDER V. AIGNER, Architect, of Józsefkörut 55, Budapest VIII, in the
Kingdom of Hungary, 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 a device for the parallel guiding of a ruler on a drawing
board, which can be arranged on any drawing board. The purpose of the invention
is to avoid the inexactitude of drawing on any drawing board of any size and
thickness and of rectangular shape resulting both from the unevenness of the draw-
ing board sides, as also from the ledge of the square, by arranging a simple
mechanism easy of manipulation without however injuring the independent use
and the transportability of the drawing board, or its being used longways or
sideways.
This device enables drawing to be done more quickly and securely and thus saves
work and time.
The device consists of a system of pulleys with an endless cord and of two
fastening devices for the square.
In the annexed drawing an example of this invention is represented.
Fig. 1 is a drawing board provided with the new device seen from below;
Fig. 2 shows the fastening devices.
Fig. 3 is a side view of the pulleys to be provided on three corners of the drawing
board.
Fig. 4 is a side view of the adjustable pulleys arranged on the fourth corner of
the drawing board.
Fig. 5 is a section through the drawing board for representing the outline of
the protecting bar for the endless cord.
Fig. 6 shows the use of a prolongation bar for drawing lines standing obliquely
to the edges of the drawing board.
Fig. 7 shows another form of construction of the fastener for the square, and
Fig. 8 shows one for the pulleys.
Fig. 9 is again another form of construction of the fasteners.
1. THE PULLEY SYSTEM.
As shown in Fig. 1 the pulley system consists of four corner pieces I, II, III, IV
which are fixed on the four corners of the back of the drawing board R. Of these
four corner pieces those indicated by I, II, and III are similar and consist, as also
shown in the side view, Fig. 3, of a plate a on which two cord pulleys b are pivoted.
The corner pieces I and III are fixed so that they bisect the right angles of the
corners of the frame whilst the corner piece II is fixed across the angle. The corner
piece IV which serves for stretching the cord and simultaneously for exactly
adjusting the ruler; consists, as also shown in the side view Fig. 4 of an angular
plate a in the two legs of which the two cord pulleys b are displaceable in guides.
These cord pulleys can be guided backwards and forwards by means of the tension

page_text: screws c. A thin supple cord E is stretched round the eight rollers of these four
corner pieces in the succession indicated by the numbers of the single rollers and
the two ends are connected with one another. The tension screws c are then turned
until the cord can easily slide over the pulleys. The beforedescribed method of
passing the cord round the pulleys allows the corresponding exterior and interior
cords of the corresponding parallel sides of the board to be moved in the same
direction as shown by the arrows in Fig. 1. By this means it is possible to use at
pleasure the square on the height or width of the board by means of the hereafter
described fasteners. A bar F (Figs. 1 and 5) is provided on the four sides of the
drawing board for protecting the stretched cord. This bar extends to the corner-
pieces leaving these latter free, in order that the cord when renewed can be easily
fitted.
2. THE FASTENERS.
Whilst for the use of the new device each drawing board must be provided with
the string rollers and the endless cord, only two fasteners are required, which in
consequence of their construction can be used on several drawing boards. These
fasteners serve for the temporary fastening of the ruler to the cord stretched on
each drawing board. The fastener shown in Figs. 2, A, B and C consists of a
hook d in which the ruler or square T lying on the drawing board R is fastened
by means of the screw e. On the hook d there is fixed a smooth, square pin f
directed downwards, on which a clamp piece 7 serving for fastening on the cord
can slide up and down. This piece is so formed that by turning the screw h
it seizes the cord E and is fixed in its position on the square pin f and in conse-
quence of its adjustability it fits to a drawing board of any thickness. When this
new device is used, the drawing board, used either broadways or sideways lies in
such a manner that the cord stretching screws are near the draughtsman, the
ruler is so laid on the drawing board that its two ends project over the drawing
board. Hereupon the cord fasteners g being opened and slid down, the one fastener
is slid along the edge of the drawing board and engages the ruler and is screwed
up; then the cord fastener is slid along the under edge of the drawing board and
fastened in position. The cord will then lie in the slot of the cord fastener g
and thus the ruler is connected with the cord. The same is then done with the
second fastener on the other end of the ruler, but for the purpose of easy movability,
there must remain a small free space of about 1mm. width between the two
fasteners and the drawing board edges. When the ruler is to be adjusted to an
already drawn line, one can adjust the same exactly by means of the cord stretching
screws, as a pulling or an easing of the same effects also a displacement of the ruler
fixed on the cord. In order to be able to move the ruler into successive parallel
positions while it lies obliquely across the drawing board, a prolongation rod i
(Fig. 6) can be used, the one end of which is fixed in the fastener k, in place of the
ruler so that this rod i lies along the edge of the board. The ruler is connected
firmly at any point by a special small clamp 7 to this rod i while the other end of
the ruler is held in its fastener as before described. This device is simplified
considerably for use in schools, as for stretching the cord there is only arranged
one screw or a tension spring. The fasteners are also of more simple construction
since the thickness of the drawing board is not so great. These fasteners (Fig. 7,
A, B, C) consist of the clamp m with the fastening screw n which serves for
fastening the ruler T lying on the drawing board R. Differing from the previously
described fastener, instead of the smooth pin there is fixed on the clamp m a square
screw o on which, between two screw nuts p and r, there is slid a fastening spring s
of bent plate and provided with a square hole. The upper screw nut p serves for
adjusting the spring s for a certain thickness of board to such a height that the
cord E lies between the opened legs of the spring. By the under screw nut r the
two legs of the spring are pressed to one another to grip the cord.
can be further simplified for use in schools as they are only bent in one piece and
The fasteners
arranged for a uniform thickness of drawing-board and ruler; in Fig. 9 d is the

page_text: spring like clamp, e is the screw for fastening the ruler, f is an angle, on the under
arm 9 of which there is arranged a small plate h round a screw i for fastening
the cord between the arm g and the plate h. The string rollers for this device are,
as shown in Fig. 8, punched out of two round plates t which are connected with
one another by means of punched out tongues u. The fastener shown in Fig. 9
consists of the clamp d, into which the screw e is screwed from above for fastening
the ruler.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :-
1. An improved device for guiding the ruler parallelly on the drawing board
having the pulley system I, II, III, and IV arranged on the back of the drawing
board, the endless cord E guided over the pulleys and fasteners for connecting
the ruler with the cord.
2. An improved device as in Claim 1 in which the endless cord E, for obtaining
similar direction of movement of the outer and inner parallel cord parts is guided
over the pulleys in the succession indicated in Fig. 1 by the numbers 1-8.
3. A device as in Claim 1 in which on one corner of the drawing board (for
instance IV) the cord pulleys b are arranged to be displaceable in guides and adjust-
able by stretching screws c.
4. A device as in Claim 1 in which the fasteners consist of a clamp d with
screws e on which the fastening pieces are displaceably attached to a rod f.
5. A device as in Claim 1 having a prolongation rod i which can be secured in
the fastener k and connected with the ruler by means of a clamp 7.
6. A device as in Claim 1 in which the fasteners consist of a clamp m on which
a square screw pin is fixed, on which by means of the two screw nuts r and pa
fastening spring s is arranged adjustably.
7. A device as in Claim 1 having a fastener bent out of one piece, consisting of
a spring like clamp d (with screw e) an angle f bent away on the under arm g of
which there are arranged a plate h and a fastening screw i.
8. A device as in Claim 1 having cord pulleys consisting of two plates t rivetted
together.
9. A device as in Claim 1 having a T shaped bar F, for protecting the cord.
1011
1
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· 100%
HERBERT HADDAN & Co.,
Agents to Applicant.