Improvements in Flexible Curves for the Use of Draughtsmen and the like.
Year: 1898

page_text: Date of Application, 11th Oct., 1898
Complete Specification Left, 11th July, 1899-Accepted, 19th Aug., 1899
Improvements in Flexible Curves for the Use of Draughtsmen
and the like.
I, WILLIAM JOHN BROOKS, of 5, Compton Street, Regent Square, London, W.C.,
Scientific Instrument Maker, do hereby declare the nature of this invention to
be as follows:
_
The invention is an appliance for drawing curves for the use of draughtsmen
and others. It consists essentially of a flexible strip of any suitable material,
on one side of which are tags of any suitable shape placed at any convenient
distances apart and attached in any suitable manner to the said strip or fashioned
of one piece with it. The instrument is used by bending the strip to the required
curve and holding it down on the paper by placing the fingers of one hand on the
tags while with the other hand the pen or pencil is drawn along the outside.
It can also be used by employing weights or drawing pins to hold down the tags.
The invention is conveniently made of celluloid, all of one piece. The tags,
which may be circular, and have a perforation at their centre to afford a better
grip to the finger tips, are joined to one edge of the strip by a narow neck and are
bent away from it at right angles so that if the tags are flat on the paper the strip
stands up on it edgewise. The tags are fashioned by cutting or stamping in any
convenient manner. It is advantageous to first bend the piece of celluloid at
right angles along a line down its length so that on one side of the bend there
is a strip of the requisite width to form the flexible part of the appliance and on
the other a strip from which certain parts are cut away so as to leave suitable
tags attached at the bend by narrow necks to the flexible strip at suitable
distances apart. To compensate for the inevitable stiffening of the strip where
the tags are joined to it the material of the strip is filed or cut away slightly or
otherwise weakened on both sides of the neck of each tag so that the effective
flexibility of the strip at the tags is the same as elsewhere. The lower edge of
the strip being at the bend aforesaid the said lower edge will have a slight bevel
or curvature which is intended to prevent the ink running on the paper. The
instrument may also be fashioned out of a flat piece of celluloid; the tags being
afterwards bent at right-angles to the strip. Instead of making the instrument
all of one piece, a flexible strip of celluloid, steel, wood or the like, may have
screwed or otherwise fastened to it several cylinders or the like of wood, celluloid,
lead, iron, brass, ebonite or other suitable material. The cylinders have their
axes at right-angles to the length of the strip, and are in contact with the latter
along a generating line. The upper edge of the strip being flush with the tops
of the cylinders, and the cylinders being slightly taller than the width of the
strip, the lower edge of the strip is lifted off the paper and so ink cannot run
thereon. Pieces of pipe of any material may be used instead of cylinders. The
cylinders, or the like, take the place of the tags beforementioned. To, com-
pensate for the weakening of the strip where the holes are drilled for the
reception of screws or the like to fasten it to the cylindrical or other blocks,

page_text: the said blocks may be flattened more or less where they are in contact with the
strip. The cylinders may be replaced by blocks of any suitable shape and material,
and tags may be formed on the strip in any other suitable way. The said
cylindrical blocks, or the like, may be fashioned of one piece with the strip by
suitably casting, moulding, cutting or otherwise shaping the material: to com-
pensate for the stiffening at the points where the tags are attached, the strip is
slightly thinned behind on each side of every tag. The tags or the equivalent
blocks may be made so heavy, of cast iron, lead, or the like, that they retain the
flexible strip in the required curve without their being held by the fingers. The
blocks may have baize or the like on their under surfaces to prevent them
damaging the paper.
Dated this 11th day of October 1898.
Improvements in Flexible Curves for the Use of Draughtsmen
and the like.
I, WILLIAM JOHN BROOKS, of 5, Compton Street, Regent Square, London, W.C.,
Scientific Instrument Maker, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:
The invention is an appliance for drawing curves for the use of draughtsmen
and others. It consists essentially of a flexible strip of any suitable material
and cross-section, on one side of which are tags of any suitable shape, placed at
any convenient distances apart, and attached in any suitable manner at intervals
along one side of the said strip, or fashioned of one piece with it. The instru-
ment is used by bending the strip to the required curve and holding it down on
the paper by placing the fingers of one hand on the tags while with the other
hand the pen or pencil is drawn along the outside. It can also be used by employ-
ing weights or drawing pins to hold down the tags when the strip is bent to the
required curve, or the strip may be maintained in the required curve by any
suitable clamping device which acts by holding adjacent tags near together or far
apart as the case may be. The flexible curve may be made in any size and have
any number of tags upon it: the larger sizes, such as cannot be controlled by the
fingers of one hand, being maintained in the required shape by weights, drawing
pins, or a suitable form of clamping device. The curve may be held in position
by any of the methods herein mentioned, whatever its size may be. The object
of providing the flexible strip with adjusting tags at intervals along its length
is that it may be used to draw a curve of sinuous character, (i.c. one which
bends backward and forward somewhat after the manner of the letter S) an object
which is unattainable if, as is commonly done, the ends only of the strip are
provided with attachments to facilitate the pulling together of the said ends.
Figures 1, 2, and 3 give in front-elevation, side-elevation, and plan respectively
one form of the flexible curve. S is the flexible strip, and T, T are the tags;
the holes in the latter being designed to give a better grip to the fingers.
As hereinbefore mentioned I do not restrict myself to any one method of
holding the curve in position, and may employ the fingers, weights, heavy tags
acting as weights, drawing pins, or any suitable clamping device. The essential
and peculiar feature of the invention consists in the provision of tags or attach-
ments of any suitable shape, size and weight at intervals along the whole length
of the flexible strip so as to enable the said strip to be bent into complex shapes

page_text: and to be better retained in those shapes, and also that the strip may be better
supported and prevented from yielding when the pen is drawn along it.
Figures 4 to 10 illustrate three methods by which the tags may be drawn
together or held apart so as to retain the strip in any required shape. Fig. 4
shows the flexible curve in plan, S being the strip; T, T, the tags; W, W, wires
hooking into the tags, and provided; one with a left handed and the other with
a right-handed screw-thread; N is a sleeve which has a right-hand and a left-
hand internal screw thread running from each end to the middle respectively,
and intended to receive the screws W, W, so that if N be turned one way both
screws enter and if turned the opposite way both screws emerge. If this com-
bination be attached to two adjacent tags as shown in Fig. 4, it will be seen that
the said tags may be held apart or drawn together at will. Any equivalent
screw-adjustment may be employed. Fig. 5, represents a section of the curve
through A B, and Fig. 6 a section through CD. The tags in Figs. 4, 5 and 6
are shown as bent pieces of metal attached to the strip by a pair of pins. Any
other suitable means of attachment may be employed. The tags may be of any
other suitable shape and may be made to form a friction-hinge or joint with the
ends of the screws W, W, which may be suitably flattened for the purpose.
In Figures 7 and 8 is shown another method of controlling the curve and
retaining it in any given shape. Fig. 7 shows the curve in plan and Fig. 8
represents a section at E F. The same letters refer to the same parts in both
figures. Short flat pieces M, M, are jointed together at J, J, and at the tags T, T,
so as to form friction-hinges thereat. It is obvious that if the strip S be bent
to any given shape it will be retained therein by reason of the stiffness of the
friction hinges. The friction hinges may be made with rivets, (R, R,), screws
(adjustable or set), eyelets, or other convenient device, and may be provided with
hollow washers or the like to insure uniform and permanent stiffness.
Figure 9 shows a third method of controlling the flexible strip. The tags T,
which are hinged to the strip by pins l' or otherwise fastened thereto, have slotted
prolongations which enable them to be clamped at any point to the slotted cross-
bar Q by means of the screws L. The slotted bars may be replaced by unslotted
bars or tubes of any section together with suitable clamps. Figs. 10 and 11
represent a section at GH: in Fig. 10 the tag is shown fashioned out of a double
strip, and in Fig. 11 it is shown as a single strip. L may be a screw-clamp of
any suitable form or any equivalent fastening. In using the form represented
in Figs. 9 to 11 the clamps L are loosened while the strip is bent to the required
shape and are then clamped tightly so as to hold the strip in the shape given
to it.
I do not confine myself to the forms of clamping arrangement shown in the
drawings, such methods of clamping being subsidiary to the main feature of the
invention but may employ any convenient adjusting and retaining device for
holding the tags (which are placed at intervals along the strip), at the required
distances from one another, thereby causing the flexible strip to acquire and
retain any desired shape.
I do not claim to have invented a new method of drawing the two ends of a
flexible strip together by means of attachments situated at or near the said ends,
as is variously done, in existing inventions, the distinctive feature of my inven-
tion being the provision of tags or the like at intervals along the whole length
of the flexible strip, thereby achieving a wide range of usefulness and applica-
bility as herein before described.
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:―
(1) A flexible curve for the use of draughtsmen and the like, substantially as
above described, in which a flexible strip of any suitable material is provided with

page_text: tags or the like at intervals along its whole length, for the purpose of holding
the said flexible curve in the desired shape and for giving support thereto.
(2) A flexible curve provided with tags or the like at intervals aiong its length
and means for adjusting the distances between the said tags for the purposes and
in the manner substantially described above.
(3) A flexible curve for draughtsmen and the like substantially as described and
shown in the drawings.
Dated this 11th day of July 1899.