IMPROVEMENTS IN DRAWING INSTRUMENTS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Simon. Hart Scott at the Office: of
the Commissioners of Patents, with his Petition, on the 20th March
1861.
I, SIMON HART SCOTT, of Rouen, France, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN DRAWING INSTRUMENTS," to be as
follows:
This Invention relates to certain improvements in the construction of instru-
ments or apparatus to be used or employed alone or in conjunction with other
instruments for producing linear drawings; or, as an addition to drawing
instruments of various forms, to be employed for the same or similar purposes.
The object of this Invention being to give motion to such instruments at
regular intervals, and to such a guage or distance apart as may be desired;
the chief purposes for which the said Invention is to be employed, is the
production of a series of section lines or rulings for heightening the effect
of linear drawings, and for other purposes for which such effects may be
required.
For the purpose of giving motion to a "set square," or other similar instru-
ment, I prefer to apply my said 'Invention in the following manner: I mount
a horizontal lever, beam, or arm upon a fulcrum, which may either be at or
near one end thereof, or at about the centre of its length, and so mount it in the
standard or carriage forming the fulcrum that it is free to vibrate therein
within the limits assigned to its action, by the projection or withdrawal of a

page_text: regulating screw or screws at the end or ends of the horizontal lever, beam, or
arm. Between the fulcrum and the set screw at the longer end of the lever,
I mount a "tumbler lever" or "foot piece" which hangs pendant below the
horizontal lever, beam, or arm, and of such a length as to come in contact with
the paper, T-square, or other fixed surface against which it is made to come in
contact upon the longer end of the lever being depressed.
This pendant "tumbler lever" or "foot piece" being set to the right or to the
left of a right angle line with the beam determines the direction of motion
either forward or backward of the instrument to which it is attached, and
as the horizontal lever, beam, or arm at its longer end is depressed, the toe
of the pendant tumbler or foot piece remains firm, and the direction of the
force applied being resolved, the whole instrument is moved forward or back-
ward, as the case may be, to the extent due to the arc traversed by the lever,
subject to the regulation of the set screw. I apply a reacting spring to return
the longer end of the beam or arm upward, to prepare it for the next
stroke or depression, and I also apply a spring to the shorter end of the
tumbler lever or foot piece so as to enable it to be returned to its normal
position.
The standard or fulcrum supporting the horizontal lever, beam, or arm may
either be mounted upon a plate having a slot or groove therein to admit of
the motor passing through it and the instrument to which it is affixed, that
it may come in contact with the paper; or, by means of an arm projecting
from the standard, the horizontal lever, beam, or arm with its fittings may be
made to overhang the instrument to which it is affixed, and so that the motor
may
ay act upon the face of a T-square or other fixed object projecting above
the surface or beyond the edge of the paper upon which the drawing is being
made; the lines may either be ruled in by hand, the pencil, pen, or other instru-
ment, being guided by the edge of the set square or other instrument or appa
ratus, or the ordinary "traverse motion" as employed in ruling machines
may be applied in conjunction with the apparatus constructed according to my
present Invention.