AN IMPROVED INSTRUMENT TO BE USED AS AN ELLIPSOGRAPH AND FOR SIMILAR PURPOSES to be
Year: 1884

page_text: I, WILLIAM ROBERT LAKE of the firm of Haseltine Lake & Co Patent
Agents, Southampton Buildings in the County of Middlesex do hereby declare
the nature of said invention for "AN IMPROVED INSTRUMENT TO BE USED AS AN
ELLIPSOGRAPH AND FOR SIMILAR PURPOSES to be as follows:-
This Invention relates to an improved instrument for describing ellipses, curves,
or circles of any desired proportions, and comprises a base or support adapted to
rest on the paper, to be marked, a frame adapted to slide laterally on guides
attached to the said support, a disc adjustably pivotted to the said support and
provided with an adjustable crank pin, and an arın carrying a marker at its outer
end and provided at its inner end with a transverse slotted head in which the said
adjustable crank pin is free to slide the said parts operating in the manner herein-
after described, to produce the desired figure. The invention consists partly in the
provision of parallel guide rods for the transverse slotted head, all of which I will
now describe."
In carrying the said invention into practice I provide a frame or base adapted to
rest on the sheet of paper or other surface to be marked, the said base being
preferably of open work or skeleton form for lightness, and to enable it to be laid
upon a drawing, without entirely covering the portion under it. The said base is
provided with parallel guide rods on which a frame is adapted to slide. The centre
of the base is provided with an upwardly-projecting pivot carrying thereon a disc
which bears against opposite sides of the sliding frame and is free to rotate in the
said frame on the said pivot.
The disc has a radial slot through which the pivot passes the said pivot being
surrounded by an externally threaded sleeve or socket which has a head wider
than the slot and bearing against the under side of the disc. A clamping nut is
screwed upon the threaded sleeve and bears upon a washer resting upon the upper
surface of the disc. The sleeve and nut enable the disc to be adjusted on the pivot,
so as to make the periphery of the disc more or less excentric to the said pivot.
When the pivot is excentric to the centre of the disc, a complete rotation of the

page_text: latter will cause the sliding frame to move first in one direction and then in the
other on the guide rods, the extent of the said movement depending upon the degree
of excentricity of the pivot. To the upper side of the disc is attached an over-
hanging plate in which is formed a radial slot and which is provided with an
adjustable crank pin adapted to be moved along the said slot and secured at any
point at which it may be adjusted, by means of a screw having an enlarged head
bearing against the under side of the overhanging plate and a squared shank
entering the slot in the said plate and prevented by its form from rotating in the
said slot so that the pin may be turned to tighten or loosen its connection with the
slotted plate.
An arm is adapted to slide longitudinally in guides in a bracket on the sliding
frame and is provided at its outer end with a pencil or marker and at its inner
end with a transverse slotted head which receives the crank pin, the said pin being
adapted to slide therein. It will be seen that when the disc is excentric to its
pivot, and is rotated, the sliding frame is reciprocated on its guides while the play
of the crank pin in the slotted head of the arm reciprocates the said arm longi-
tudinally or in a direction at right angles to the movement of the sliding frame.
The two movements thus imparted to the arm viz-the lateral movement caused
by the sliding frame on the guides, and the longitudinal movement caused by the
crank pin, produce a compound or elliptical movement of the marker which
therefore marks an elliptical figure on the paper on which it rests.
The proportions of the ellipse and the relative lengths of its major and minor
axes depend upon the adju-tinent of the disc on its pivot, and the adjustment of
the crank pin relatively to the centre of the disc, hence an ellipse of any desired
-form-and-as-small-as-may-be desired.can-be.produced, the marker being entirely at
one side of the mechanism that operates it, so that it is not prevented thereby
from making very small figures. It is obvious that curves or parts of ellipses may
be made with equal facility.
The disc may have suitable marks or graduations by the side of the slot, and the
overhanging plate may have similar marks to guide the operator in adjusting the
disc on its pivot and the crank pin on the said plate. When the disc is adjusted
so that it is concentric with its pivot the rotation of the disc will not move the
sliding frame, hence the reciprocating movement of the arm will produce a straight
line. An ellipse can thus be readily bisected.
.
Guide rods are provided which are supported by standards affixed to the corners
of the sliding frame and arranged parallel with the marker carrying arm. The
ends of the slotted head are grooved and bear against the inner sides of the said
rods. The arm is thus steadied in its reciprocating movements and prevented from
wobbling. The slotted over-hanging plate may be omitted and the slot in which
the crank pin is adjustably held may be formed directly in the disc either as a
continuation of the slot, or independently thereof. This change would involve the
lengthening of the crank pin.
1 1001
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: I, WILLIAM ROBERT LAKE, of the firm of Hasletine, Lake, & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "AN IMPROVED INSTRUMENT TO BE USED AS AN ELLIPSO-
GRAPH AND FOR SIMILAR PURPOSES" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to an improved instrument for describing ellipses, curves
or circles, of any desired proportions, and comprises a base or support adapted to
rest on the paper to be marked, a frame adapted to slide laterally on guides
attached to the said support, a disc adjustably pivoted to the said support and
provided with an adjustable crank pin, and an arm carrying a marker at its outer
end and provided at its inner end with a transverse slotted head in which the said
adjustable crank pin is free to slide, the said parts operating in the manner
hereinafter set forth to describe the desired figure. The invention consists partly
in the provision of parallel guide rods for the transverse slotted head, all of which
I will now describe.
In the accompanying drawing.
Figure 1 represents a plan view of the improved instrument.
Figure 2 represents a section on the line xx, Figure 1.
Figure 3 represents a section on the line y y Figure 1.
Figures 4 and 5 represent respectively sectional views on the lines z z, and ¹ s¹,
Figure 2, drawn to an enlarged scale.
Similar letters of reference indicate corresponding parts in the several figures.
a indicates a frame or base adapted to rest on the sheet of paper or other surface
to be marked, said base being preferably of open or skeleton form for lightness, and
to enable it to be laid upon a drawing without entirely covering the portion under
it. The base a is provided with parallel guide rods bb, on which a frame c is
adapted to slide. The centre of the base a is provided with an upwardly
projecting pivot f on which is pivotted a disc g, which bears against opposite sides
of the frame c and is free to rotate in the said frame on the pivot f.
The discy has a radial slot i through which the pivot passes, said pivot being
surrounded by an externally threaded sleeve or socket j, which has a head j' wider
than the slot i, and bearing against the under side of the disc g.
A clamping nut is screwed upon the threaded sleeve j and bears upon a
washer resting upon the upper surface of the disc g. The sleeve and nut enablo
the disc to be adjusted on the pivot, so as to make the periphery of the disc more
or less eccentric to the said pivot. When the pivot is eccentric to the centre of the
disc, a complete rotation of the latter will cause the frame c to move first in one
direction and then in the other on the guide rods bb, the extent of the said
movement depending upon the degree of eccentricity of the pivot. To the upper
side of the disc g is attached an overhanging arm or plate m, in which is formed a
radial slot n, and which is provided with an adjustable crank pin 8, adapted to be
moved along the said slot and secured at any point at which it may be adjusted,
by means of a screw t having an enlarged head bearing against the under side of
the arm m and a squared shank entering the slot in the said arin and prevented,
by its form, from rotating in said slot, so that the pin may be turned to tighten or
loosen its connection with the slotted arm.
o indicates an arm adapted to slide longitudinally in guides in a bracket p on
the frame c, and provided at its outer end with a pencil or marker q, and at its
inner end with a transversely slotted head o' which receives the crank pin 8, the
said pin being adapted to slide therein.

page_text: It will be seen that when the disc y is eccentric to its pivot and is rotated, the
frame c is reciprocated on its guides b b, while the play of the crank-pin 8 in the
slotted head of the arm o reciprocates the said arm longitudinally or in a direction
at right angles to the movement of the frame c. The two movements thus
imparted to the arm, viz-the lateral movement caused by the frame c on the
guides bb, and the longitudinal movement caused by the crank pin 8, produce a
compound or elliptical movement of the marker q, which therefore marks an
elliptical figure on the paper on which it rests.
The proportions of the ellipse and the relative lengths of its major and minor
axes depend upon the adjustment of the disc g on its pivot, and the adjustment of
the crank-pins relatively to the centre of the disc, hence an ellipse of any desired
form, and as small as may be desired, can be produced, the marker being entirely
at one side of the mechanism that operates it, so that it is not prevented thereby
from making very small figures. It is obvious that curves or parts of ellipses may
be made with equal facility.
The disc g may have suitable marks or graduations by the side of the slot i, and
the arm m may have similar marks to guide the operator in adjusting the disc on
its pivot and the crank pin on the slotted arm. When the disc g is adjusted so
that it is concentric with its pivot, the rotation of the disc will not move the
frame c, hence the reciprocating movement of the arm o will produce a straight
line. An ellipse can thus be readily bisected.
indicate guide rods supported by standards affixed to the corners of the
frame o and arranged parallel with the marker carrying arm o. The ends of the
slotted head o¹ are grooved and bear against the inner sides of the said rods, as
shown in Figures and 3. The arm o is thus steadied in its reciprocating
movements and prevented from shaking. The slotted overhanging arm m may be
omitted and the slot n in which the crank-pin 8 is adjustably held may be formed
directly in the disc y, either as a continuation of the slot i or independently
thereof. This change would involve the lengthening of the crank-pin.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
First. The improved ellipsograph composed of a base or support, a disc adjustably
pivoted thereto, a frame, c adapted to slide on guides on the base and enclosing the
disc g, a marker-carrying arın adapted to slide in a guide formed on the frame c and
provided with a 'transverse slotted head, and an adjustable crank-pin connecting the
said head with the disc or with an attachment thereof, as set forth.
Second. The combination of the base or support a having a fixed pivot pin f, the
threaded socket on said pivot, the slotted disc adjustable on said socket, means for
positively securing the said disc to the socket in any position to which the disc
may be adjusted, the slotted arm secured to said disc, the sliding frame c sur-
rounding said disc, the marker carrying arm having the slotted transverse head,
and the adjustable crank-pin, all arranged and operating substantially as described.
Third. The combination of the frame c having the guide rods uu, the marker
carrying arm o adapted to slide in guides formed on said frame, and provided with
the slotted transverse head supported and guided by said rods, and means sub-
stantially as described for reciprocating said frame and arm each in a direction at
right angles to the reciprocating movement of the other, as set forth.
1100.
HASELTINE, LAKE & Co.,
For the Applicant.