Improvements in Drawing Instruments.
Year: 1894

page_text: Date of Application, 24th Jan., 1894
Complet Specification Left, 24th Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Drawing Instruments..
1, GEORGE WRIGHT, of 2 Long Lane, Aldersgate Street, in the City of
London, Stationers Sundriesman, do hereby declare the nature of this invention.
to be as follows:-
This invention has for its object to construct a combination drawing instrument
specially applicable for executing drawings on a blackboard or on paper in the
absence of compasses and other instruments, and consists of a combination of an
ordinary measuring or setting off scale, a protractor, and of means for describing
circles of various diameters without the use of compasses.
At
In-an-instrument-constructed according to this invention a scale is divided along
one edge as an ordinary measuring or setting off scale, in any proportions, while
the other edge is divided with angles by lines radiating either, from a centre mark
or point in the opposite edge, or from a point in the centre of the scale.
this latter point is secured a knob or handle through which passes a pointed pin
or needle capable of adjustment by means of a screw so as to project the point
beyond the under surface of the scale or withdraw it at pleasure. Down the centre
of the scale are bored holes at any predetermined distance apart for the reception
of crayon or pencil points, as the case may be.
When using the scale for describing circles the central point is projected
through the scale and the crayon or pencil point passed through one of the holes
on either side of the centre, the middle point being then placed on the required
centre and the scale rotated when the necessary circle is described.
When using the instrument as a setting off scale, as a straight edge, or as a
protractor the middle point is withdrawn by means of the attached screw to prevent
scratching.
Dated this 24th day of January 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Drawing Instruments.
I GEORGE WRIGHT, of 2 Long Lane, Aldersgate Street, in the City of
London, Stationers Sundriesman, 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 has for its object to construct a combination drawing instrument
specially applicable for executing drawings on a blackboard or on paper in the
absence of compasses and other instruments; and consists of a combination of an
ordinary measuring or setting off scale, a protractor, and of means for describing
circles of various diameters without the use of compasses.
In the accompanying sheet of illustrative drawings:
:-
Fig. 1 represents a longitudinal section of an instrument constructed according
to this invention, and Fig. 2 is a plan of the same.
A scale or ruler a is divided along one edge as an ordinary measuring or
setting off scale, in any proportions, while the other edge c is divided with angles

page_text: to form a protractor by lines radiating from a point d in the edge In the centre
of the scale a is secured a knob or handle e through which passes a pointed pin or
needle secured to the milled-headed screw, g working in the screw threaded
plate secured in the knob e. By means of the said screw the pin f may be readily
adjusted so as to project its point beyond the under surface of the scale or withdraw
it at pleasure. Down the centre of the scale a are bored holes i at any predeter-
mined distance apart for the reception of crayons, pencil points, or other marking
substance as the case may be.
When using the scale for describing circles the central point is projected through
the scale, and the crayon or pencil point passed through one of the holes on either
side of the centre, the needle point being then placed on the required centre and
the scale rotated when the necessary circle is described.
When using the instrument as a setting off scale, as a straight edge, or as a
protractor the needle point is withdrawn by means of the attached screw to prevent
scratching.
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 :-
1. A scale or ruler perforated with holes and having an adjustable point, the
whole substantially as described and for the purpose set forth.
2. A scale or ruler a with holes i in combination with a needle secured to an
adjusting screw 9 working in the handle e substantially as described.
3. The combination of parts constituting my improved drawing instrument, the
whole arranged and constructed substantially as described in the foregoing
Specification and illustrated in the drawings hereunto annexed.
Dated this 24th day of October 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.