Improvements in the Construction of Ellipsographs.
Year: 1894

page_text: Date of Application, 8th Nov., 1894
Complete Specification Left, 9th Sept.. 1895-Accepted, 8th Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Ellipsographs.
I, THOMAS MOY, of 8 Quality Court, London W.C., Engineer, do hereby
declare the nature of my said invention to be as follows:-
If a cone, or a frustum of a cone, or two or more cylinders united endwise, is or
are caused to receive angular reciprocating motion about a central longitudinal
axis, and, simultaneously therewith, a longitudinal reciprocating motion upon or
along the same axis, by means of a rotating crank pin (or equivalent device) of
smaller radius than the radius of the point operated upon; then the paths travelled
by any other points of larger or smaller radius than that of the crank, will be such
as would project elliptical lines upon tangential planes, the respective diameters of
which will correspond in one direction with the diameter of the transmitting circle
described by the crank pin, and in the other direction with the diameters of those
parts of the cylinder or cone in which the operating points are situate.
The object of my invention is to construct ellipsographs in such a manner as to
utilise the aforesaid transmitting motions.
The cylinders, cones, and frustums of cones may be mutilated or modified and
reduced to a mere skeleton frame, or radial arms, and the like.
One form of my invention consists in mounting upon a suitable frame a slotted
bent bar, or a plate, fitted with pins or rods in line with each other. The pins or
rods slide and rotate freely in bearings. The bent bar or plate is fitted with a flat
bar, which is made capable of receiving reciprocating angular and longitudinal
motions by means of one or more crank pin or pins radially adjustable. Guide
plates are fitted to the bent bar or plate and to a sliding guide plate respectively,
so as to carry and support a pencil, pen, or other instrument.
In using a drawing pen an additional link or guide is used so as to hold the pen
at a tangent to the ellipse at all points.
By adjusting the crank pin or pins, the diameter of the ellipse in one direction is
determined; and by adjusting the position of the pen or pencil holders, the diameter
of the ellipse in the other direction is determined.
The instrument is preferably made so that it is capable of describing a given
circle and a given straight line, and any ellipse between those extremes.
Dated 8th November 1894.
J, THOMAS MOY, of 8 Quality Court, London W.C, Engineer, do hereby
declare the nature of my said invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of my invention is to effect improvements in the construction of

page_text: And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which similar
figures of reference indicate corresponding parts.
Fig. 1 is an elementary diagram, illustrating the principle upon which my
invention is founded.
Fig. 2 is an elevation and Fig. 3 a plan, illustrating one method of constructing
an instrument according to my invention.
Figs. 4 to 7 show details of parts of Figs. 2 and 3, and variations in the
construction of some of those parts.
Fig. 8 is an elevation and Fig. a plan on the line a b of Fig. 8, illustrating a
simple and cheap modification of the instrument.
Figs. 10 to 13 are detail views.
Referring to Fig. 1. If a cone 14, or a frustum of a cone, is caused to receive
angular reciprocating motions about a central longitudinal axis 15, and, simul-
taneously therewith, longitudinal reciprocating motions upon or along the same
axis, by means of a driven crank pin (or equivalent device) rotating in a circle,
located, for instance, at 16; then the paths travelled by any other points on the
surface of the cone of larger or smaller diameter than that occupied by the crank,
and located, for instance, at 17 and 18, will be such as would project elliptical lines
upon tangential planes, the respective diameters of which will correspond in one
direction with the diameter of the transmitting circle described by the crank pin 16,
and in the other direction with the radii of those parts of the cone in which the
operating points (such as 17 and 18) are situate.
Referring to Figs. 2 to 7-19 is the lower frame of the instrument, 20 is the
front A frame and 21 the back A frame. 22 is a slotted bent bar fitted with pins
or rods 23, 23, in line with each other. The bars 23 sli le freely in holes 24 formed
in the front and back frames 20 and 21. Separate face views of these frames 20
and 21 are shown in Figs. 6 and 7. The bent bar 22 is fitted with a flat bar 25.
26 is a frame pivoted at 27, carrying an adjustable sliding block fitted with a
vertical pin 30 passing through a hole or bearing in the bar 25. By means of the
regulating screw in the frame 26 the pin 30 can be adjusted to any position from
the centre to the end of the frame 26. On the frame 26 being turned upon its
centre 27, by means of the pin 30, such motion causes the bar 22 to receive angular
and longitudinal reciprocating motions, as before described.
28 is a flat plate, having a longitudinal slot 39 sliding upon a pin 40. This
plate 28 also slides freely in the slot 29 (see Fig. 7) formed in the frame 21. The
plate 28 carries a tube 31, rigidly attached thereto, which retains its vertical
position at all times. The tube 31 carries a stylographic pen, graver, or pencil,
for delineating the required ellipse. 33 is a sliding plate fitted to the bar 22 and
perforated to receive the tube 31. The plate 33 is capable of being fixed at any
part of the slot in the bar 22.
By adjusting the position of the pin 30, the major diameter of the required
ellipse is determined, and the position of the slide 33 upon the bar 22 determines
the minor diameter, as shown in Fig. 3.
Fig. 4 is an elevation and Fig. 5 a plan showing another method of forming the
bar or plate 22. 34 is a flat plate, bent at right angles at each end to form
flanges 35 and 36. To these flanges the rods 23, 23, and bar 25 are fixed.
37 is a
slot by which the guide plate 33 is clamped in any position by the set screw 38;
the scale being adapted so that the apparatus may be used to describe a given
circle and a straight line, and any ellipse between those extremities. A similar
scale is delineated upon the slotted bar 22 (not shown on the drawing).
Referring to Figs. 8 and 9:-19 is a plate, to which forked guides 41, 42, are
attached, either permanently in position, as shown, or hinged so as to fold down
upon the plate 19. 43 is a bar having one limb 44 fitted with a ball 45 at its lower
end. The other end of the bar 43 is fitted with a bracket 46, of any suitable kind,
carrying the pen or pencil tube holder 47 and tube 31. The pen or pencil 48 fits
the tube 31 with sufficient friction to prevent slipping, or it may be made to screw

page_text: thereinto. The position of the tube holder 47 in the bracket 46 can be adjusted
by the set screw 49, so as to increase or diminish the diameter of the ellipse,
transversely to the plate 19, the other diameter being governed by the position of
the ball 45 relatively to the centre 27, upon which the frame 26 revolves, regulated
by the screw. The ball holder 50 is bored to receive the ball, and is tapped so as
to act as a nut to the screw.
When operating with this instrument the ball 45 may rest upon the screw and
the pen, pencil or graver 48 rests upon the paper or other surface while forming
the ellipse.
Instead of employing a ball and screw, as shown in Figs. 8 and 9, I sometimes
employ detachable corrugated or grooved circular plates (of which a few may be
kept with each instrument) the end of the limb 44 being pointed so as to engage in
and travel round one of the grooves, while the limb at the other end describes the
ellipse. Fig. 10 is an end view showing the guide 41, the pointed limb 44 and the
plate 51 in position. Fig. 11 is a plan of the plate 51, and Fig. 12 is an enlarged
section showing one method of forming the grooves or corrugations.
The plates 51 may, if preferred, be stamped out of thin metal and made to
engage on pins or dowels in the plate 19, or they may be formed to fit into a recess
prevent shifting, when in use.
to
sometimes make the limb 44 detachable and adjustable, whereby the radius of
the transmitting and operating limbs of the instrument may both be regulated in a
similar manner.
Although not shown in Figs. 2 to 5, I prefer to fit cylindrical on ball bearings in
the plates 25 and 33, so as to provide for the angular motions of the pin and pencil
or other holders, as indicated in Fig. 13.
The illustrations accompanying this Specification, and therein described, are
intended to be understood and taken as explanatory of the nature of the invention;
as it is obvious that the instrument is capable of being constructed, on the one
hand, in a very simple manner, by means of a slotted cone fitted with adjustable
transmitting and operating points; and, on the other hand, in an elaborate manner,
with micrometrical adjustments at both ends of the instrument.
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. In the construction of ellipsographs, the application and use of a complete or
mutilated cone or frustum of a cone, or its or their equivalents, so arranged and
operating that the same may receive combined reciprocating angular or radial and
longitudinal axial motions simultaneously, substantially as and for the purposes
described and illustrated by the drawings.
2. The improvements in the construction of ellipsographs substantially as
hereinbefore described and illustrated by the drawings.
Dated 7th September 1895.
GEO.
DOWNING,
8 Quality Court, London, W.C., Agent.