An Improved Sectioning Set Square, for Drawing Equidistant Parallel Lines in any Direction, of Variable Pitch
Year: 1888

page_text: Date of Application, 19th July, 1888
Complete Specification Left, 18th Oct., 1888
Complete Specification Accepted, 7th Dec, 1888
RESERVE C
An Improved Sectioning Set Square, for Drawing Equidistant Parallel
Lines in any Direction, of Variable Pitch
We WILLIAM PARKES of 84 Grt. Tindal Street Ladywood, Birmingham in the
County of Warwick Engineer and Machinist and CHARLES WAKEMAN (Manager) of
"Carisbrooke" Cambridge Road, Moseley, Birmingham in the County of Warwick
do hereby declare the nature of this invention to be as follows
:―
The principle upon which our improvement is based is that of "direct frictional
contact of a flat end or point, say of a stud or pin, with the surface of the paper, or
other material upon which the lines are to be drawn, by pressure exerted upon it by
hand, which said contact resists, by suitable combinations hereafter described, the
further advance of the set square or slide, to which the said stud is attached, as it is
moved along by the finger or pencil point.
By this said "frictional contact" directly with the surface of the paper, the chances
of slipping are reduced to a minimum, and by virtue of its flat end or point, the paper
is not marked in the slightest degree.
The movements of this said stud end or point, by which the spacing is obtained for
drawing these equidistant lines, are as follows:-
The stud with its frictional end or point is connected to a horizontal slide, which is
free to move in either direction, and is attached to the set square. The stud therefore
partakes of exactly the same movement.
The "travel" of this said slide is regulated by a second slide-which is adjustable,
and connected with the former.
In proportion as the second or adjustable slide is moved along the surface of the
former, and there secured, either by the friction of itself due to its shape, or by an
additional screw or screws; in the same proportion will it limit the travel of the stud
end or point, which said travel will always be the distance or pitch between each
line.
A Vernier may be marked either on the first mentioned slide or the second adjustable
slide, for convenience in setting the pitch.

page_text: The said stud with its frictional end or point besides having this transverse
measuring movement, is capable of an additional movement in a vertical direction,--
and the mechanical combinations are so arranged, that this movement is quite
independent of the former, that is to say, when pressure is put upon the head of the
stud, the frictional end or point tightly engages the paper by slightly descending, it
does not at all influence the movements of the slide to which it is attached, nor, during
such pressure will it tighten the set square upon the paper, but it remains free to be
moved with the finger or pencil point.
A Hole is made in the set square in a convenient position, and through this hole,
the said stud end or point engages directly with the surface of the paper &c. The
spacing in the sectioning set square as hitherto constructed has been accomplished in
various ways usually by means of rackwork attached either to the face or edge of the
T-square and sometimes to the set square itself; and in other arrangements a point
or knife edge is caused to engage with the blade of the T square or vice versa ; and,
by this means the required lifts are taken for the advancement of the set square for
every successive line drawn.
;
In our invention the T square is not damaged in the least degree by the fixing of
rackwork, nor is its edge or surface cut or pierced by the repeated "bite:" of the
instrument upon it.
The square is quite independant, and it forms no part of the sectioning arrange-
ment, nor is it used except as in the ordinary way, viz: as a medium upon which the
set square slides as it is stepped along.

page_text: Fig. 6 End sectional elevation of ditto.
Fig. 7 The stud with its frictional end in contact with the paper.
Fig. 8 Shows the method of using the set square, by means of the ordinary
T square and drawing board, for drawing lines from left to right, and vertical
lines.
Fig. 9 Ditto, but for drawing lines from right to left, and horizontal lines.
Fig. 10 Shows method of drawing lines in any direction, by using the blade of the
T square as a straight edge.
A set square. B loose horizontal slide attached to set square, for the horizontal
movement of the stud or frictional point. C second adjustable slide, limiting the travel
of the stud point attached to the former slide. D stud connected to the horizontal loose
slide. E the Vernier for convenience in setting. F vertical movement of stud, by
pressure in the direction of the arrow. G screws or pins, by which the horizontal
slide is attached to the set square. H the hole in the set square, through which the
stud point operates. I the frictional point which engages the paper. J the
paper.
The mode of working the instrument is as follows:-
Place the square against the edge of the drawing board, and the set square
against it, as in the ordinary way, and draw the first line; while thus held, push
forward the horizontal loose slide B, (or the stul which will carry the said slide with
it) with the finger or pencil point, until it comes to the extremity of its travel, then
press with the first finger of the left hand upon the head of the stud D, releasing the

page_text: others from the set square. The stud mounted as it is upon the slide B slightly
descends, and the point I engages the paper, represented by the lines J, through the
hole H in the set square. All that is now necessary is to advance the set square, in
the same manner as the slide; viz., by the finger or pencil point, until it is stopped in
its advance, then, by bringing down the fingers upon the set square as at first, the stud
may be released and the second line drawn.
Or briefly stated (a) draw the first line. (b) push the slide to the extremity of its
travel. (c) press upon the stud. (d) advance the set square to the extremity of its
travel. (e) draw the second line &c. We have now described the nature of our
improvement, and the manner in which it is performed, but we do not limit ourselves
to the precise detail hore given, it may be varied, without departing from the nature
of our improvement, namely, that of direct frictional contact of a point, say of a stud,
with the paper by pressure exerted upon it by hand, through a hole in the set square;
for instance, the frictional point I need not necessarily be the point of a stud, it may
take any other shape and the point itself marked I on the drawings need not be the
same material as the body of the shank, nor need the sectioning principle or
arrangement here described be confined to the 45° degree set square but it
may be fitted to any other angle to curved surfaces, or to the T square itself.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is;
1st. The frictional point or end I which engages directly with the paper by pressure
exerted upon it by hand through the hole H in the set square.
2. The horizontal loose slide B.
3. A second adjustable slide C connected to the former.
4. The Vernier E.
5. The hole H in the set square, the whole used in combination being constructed
arranged and worked substantially as described and illustrated for the purposes set
forth.