IMPROVEMENTS IN SET SQUARES OR "ANGLES" USED IN ARCHITECTURAL OR MECHANICAL DRAWING OR MEASUREMENT
Year: 1878

page_text: LETTERS PATENT to William Carr Crofts, of Adel, near Leeds, in the County
of York, Architect, for the Invention of "IMPROVEMENTS IN SET SQUARES
OR "ANGLES" USED IN ARCHITECTURAL OR MECHANICAL DRAWING OR
MEASUREMENT
"
Sealed the 29th November 1878, and dated the 4th June 1878.
PROVISIONAL SPECIFICATION left by the said William Carr Crofts at the
Office of the Commissioners of Patents on the 4th June 1878.
WILLIAM CARR CROFTS, of Adel, near Leeds, in the County of York, Architect.
IMPROVEMENTS IN SET SQUARES OR "ANGLES" USED IN ARCHITECTURAL OR
MECHANICAL DRAWING OR MEASUREMENT."
The object of the Invention is to facilitate the operation of architectural or
mechanical drawing or measurement. For this purpose the set squares or angles
employed in architectural or mechanical drawing or measurement are, in carrying
out my improvements, of the ordinary open or skeleton character, but I generally
form them with slightly bevilled internal edges, so as to bring the upper surfaces
towards such internal edges as near as convenient to the surface of the paper or
other material on which the drawing is being produced or measured; and on this
upper surface of the set square or angle I engrave or otherwise form scales by lines
drawn towards the internal edges of such upper surfaces, and at right angles or
inclined to the respective sides of such set squares or angles, and from angle to
angle of the respective internal sides or edges, commencing with an unit of
measure and its subdivisions in each direction. By this arrangement not only will
great economy of time and labor and increase of accuracy and cleanliness in their
application, arising from the combination in function of the two instruments, the
set square or angle and the scale be primarily secured, but, incidentally, con-
siderable economy of space and material and increase of portability will be attained
by their combination in structure.

page_text: There may be only one pair (for vertical and horizontal dimensions respectively),
or in addition a series of scales of any other desired conventional magnitudes, one
or each being drawn or otherwise engraved, as herein-before mentioned, towards
the respective internal sides or edges of the upper surfaces depending on the side of
the set square or angle; and these scales are applied on both the upper and under
surfaces of such set squares or angles, that is to say, scales will appear along the
internal sides or edges of the angles' surfaces, whichever side is for the time
uppermost.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Carr Crofts in the Great Seal Patent Office on the 2nd
December 1878.
WILLIAM. CARR CROFTS, of Adel, near Leeds, in the County of York, Architect.
"IMPROVEMENTS IN SET SQUARES OR "ANGLES" USED IN ARCHITECTURAL OR
MECHANICAL DRAWING OR MEASUREMENT."
The object of the Invention is to facilitate the operation of architectural or
mechanical drawing or measurement. For this purpose the set squares or angles
employed in architectural or mechanical drawing or measurement are, in carrying
out my improvements, of the ordinary open or skeleton character, but I generally
form them with slightly bevilled internal edges, so as to bring the upper surface
towards such internal edges as near as convenient to the surface of the paper or
other material on which the drawing is being produced or measured; and on this
upper surface of the set square or angle I engrave or otherwise form scales by lines
drawn towards and impinging on the internal edges of such upper surfaces, and at
right angles or inclined to the respective sides of such set squares or angles, and
from angle to angle of the respective internal sides or edges, commencing and con-
tinuing with an unit of measure and its subdivisions in each direction. By this
arrangement not only will great economy of time and labor and increase of accuracy
and cleanliness in their application, arising from the combination in function of the
two instruments, the set square or angle and the "scale" be primarily secured, but,
incidently, considerable economy of space and material and increase of portability
will be attained by their combination in structure.
There may be only one pair (for vertical and horizontal dimensions respectively),
or in addition a series of scales of any other desired conventional magnitudes, one
of each being drawn or otherwise engraved, as herein-before mentioned, towards
and impinging on the respective internal sides of edges of the upper surfaces
depending on the side of the set square or angle; and these scales are applied on
both the upper and under surfaces of such set squares or angles, that is to say,
scales will appear along and impinging on the internal sides or edges of the angles'
surfaces, whichever side is for the time uppermost.
But that the Invention may be the better understood I will by the aid of
the accompanying Drawings proceed to describe means pursued by me in carrying
the same into effect.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 represents one face or side of an angle or set square with the indications
thereon arranged according to my Invention; Figure 2 represents the opposite side
or face of the same angle; and Figure 3 represents a section through any one of the
sides a, b, or c, of the angle or set square.
The slighly bevilled edge a¹ corresponds with the inner edge of either of such
sides a, b, or a
The scales e, f, g, h, i, j, may be of any desired proportion, and the angles with
suitable scales applied I call a "scale set square."
The scales e, f, are a pair of ordinary scales fully divided into feet and inches
for horizontal and vertical dimensions respectively.
In use this scale set square
will be placed on the T square in the usual position, so that scale e is horizontal
and scale f vertical, the lines being drawn along their internal edges in accordance
with the required dimensions.
The scale g represents a fully divided protractor for angles of any degree. The
internal angle, where the scales e and ƒ meet, is placed on the line at the point
from which the desired angle is to be drawn, so that some other part of the line
(or the line produced) cuts the protractor at the required angle, as indicated on it,
a line being drawn along the internal edge of either scale, e or f
The scale h is intended for use in dividing for the setting out of joists and rafters.
In use it is placed on the T square horizontally, the lines being drawn along the
internal edge of the scale i, which would then be in a vertical position, as each
division is slid on in succession to the line first drawn (or to a dot in the case of the
quarter-inch joists).
The scale is for risers, and in use the scale set square is placed against another
set square, which is held firmly in position; a dot is marked opposite the top or
bottom division of the chosen series, the lines being drawn along the internal edge
of scale h, which is laid horizontal as each division is slid on in succession to
the dot.
The scale j is intended for use in obtaining the division for treads, and it is
worked in a similar way, the lines being drawn along the internal edge of scale i
which is horizontal.
Having thus described my Invention, and means which I adopt in carrying the
same into effect, I would have it understood that I do not confine myself to the
precise scales indicated, as they are only given by way of illustration; but what I
claim as the essence of my Invention is, the improvements in the manufacture of
set squares or angles used in architectural or mechanical drawing or-measurement,
by engraving or otherwise, forming scales of any desired proportion on the upper
surfaces of skeleton set squares towards and impinging on the internal edges of
such set squares, whereby facility is obtained in setting out such drawings, sub-
stantially as described.
In witness whereof, I, the said William Carr Crofts, have hereunto set my
hand and seal, this Twenty-seventh day of November, in the year of our
Lord One thousand eight hundred and seventy-eight.