Year: 1896

page_text: Date of Application, 8th May, 1896-Accepted, 15th Aug., 1896
Figs. 4 to 18 are different details of the mechanism.
On three corners of the drawing-board A are fixed bearings B for the two
rods C, of which one lies on the longitudinal edge and the other on the side edge
of the board. Upon these rods C is guided the apparatus with its guide-
bearings D.
The guide-bearings D are fixed on the plate E carrying the semi-circular
disk G, with divisions of degrees, in which is provided a slit G¹ for the guiding of
a pointer F. The pointer F turns round the pin H, which latter forms also the
pivot for the bevelled toothed wheel K connected solidly with the rule J. The
scales Larranged along two sides of the drawing-board are formed on the under
side as toothed racks, in which gears the wheel N keyed on the axle M provided
with different projections. The wheel N, by moving the axle M endwise in the
bearings O and O, is brought into or out of gear with the toothed rack and the
respective positions are fixed by means of the lever P and the corresponding
hollows p and pl in the axle M. Upon the axle M is also loosely fixed a bevelled
toothed wheel K which by means of the lever Q can be moved in a groove k
provided in the axle-piece m' and hereby a gearing with the corresponding wheel K
can be effected or prevented. The lever Q is fixed in one of its two limiting
positions by the spring g', springing in the corresponding hollow q. As may be
seen from Fig. 1 also the rule J is provided with a scale, the use of which is
described hereinafter.
As herein before mentioned, the apparatus can be used for drawing horizontal
and vertical lines, parallels, any angles and arcs and is a convenient instrument for
the construction of perspective drawings.
The horizontal lines are drawn in such a manner, that the pointer F is placed
at 90° and then fixed by screwing up the nut h. The rule J is thus fixed and can
be used like a T square. The up and down movement of the rule at the side of
the drawing-board can be effected by turning the wheel S, if previously by moving
the axle M in the bearings O and O' the spur-wheel N gears with the toothed
rack 1, which position is secured by the lever P engaging in the groove p.
In order to prevent oscillation of the rule, the pressing screws d of the
guide-bearings D are screwed up and the bearings D are thus pressed on the
guiding-rods C, without however too great friction."

page_text: Vertical lines can be drawn in two ways. By putting the apparatus upon the
guiding rod C of the longitudinal side and repeating the aforesaid process as above
mentioned for drawing the horizontal lines; or also by using the holes bored into
the rule J, if the vertical lines to be drawn are at such distance from one another,
as are indicated by the position of such holes. As may be seen from the drawing
(Fig. 1) the rule J is provided with holes indicated in two ways, through which
holes either a pencil or a drawing pen can be put for drawing the lines possible by
their means. The rule is divided by means of a middle line into an upper and an
under half. The edge of the upper half of the rule is divided according to a
millemeter or other scales, lines being made perpendicular to the edge to represent
the millemetres or other unit division. Every tenth line is prolonged to the centre
line of the rule and from the point where it intersects the said centre line an
oblique line is drawn to the base of the previous tenth line. The lines intermediate
between these tenth lines are prolonged perpendicularly to the edge to intersect
the said oblique lines, and at each point of intersection (except for the fifth line)
a hole is made through the rule. The fifth line is produced to intersect the middle
line of the rule and at this place a hole is made. The holes of the under half of
the rule serve for drawing arcs, which have their centre in the pivot of the rule, at
pin H and which have the measures indicated upon the rule by numbers, as their
radius. They all lie upon ares round the centre H and upon corresponding
horizontal lines at the distance of of the halfrule-breadth. In order to draw the
arcs, the spur-wheel N is taken out of gear with the toothed rod by moving the
axle M and the bevelled wheel K' is moved by means of the lever Q in the groove k
and brought into gear with the bevelled wheel K, whereby it is then possible to
turn the rule round the pin H by turning the wheel S.
Parallel lines, not horizontal or vertical, are drawn by correspondingly displacing,
the pointer F and the necessary inclination is. thus given to the rule. Angles are
also found by placing the pointer F upon the corresponding number arranged on
the semi-circle G and by drawing in the direction indicated by the rule.
Perspective drawing is considerably facilitated by using the pivot H of the
rule J as vanishing point.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
An adjustable drawing-rule for straight lines, angles and arcs, having a pin H
lying in the head of the rule and round which the latter can be turned by means of
bevelled wheels K and K', whereby the corresponding angle to the edge of the
board is found from a divided are G, circles of any diameter can be drawn by
placing the drawing-pen or the like in holes provided on the rule; or after having
fixed the movable head on the pin H and put the driver-wheel N into the
corresponding toothed rack arranged on the board and provided with a measure-
scale, said rule can be moved parallely for distances to be read on this scale.
Dated this 8th day of May 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C.,
Agents to Applicant.