A New or Improved Instrument for Drawing Broken or Dotted Lines.
Year: 1895

page_text: Date of Application, 25th June, 1895
Complete Specification Left, 25th Mar., 1896-Accepted, 25th Apr., 1896
PROVISIONAL SPECIFICATION.
A New or Improved Instrument for Drawing Broken or
Dotted Lines.
I, JAMES HARMER KNIGHT, of 28 Westview Avenue, Germantown, Phila-
delphia, in the United States of America, Engineer and Draughtsman, 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:-
My invention relates to improvements in that class of drawing instruments
employed for making broken lines in which the motion of the instrument, acting
through suitable mechanism raises and drops the pen, pencil, or other marking
device, causing it to form dots, dots and dashes or any other desired form of broken
line, according to the mechanism used. By my invention I am enabled to produce
an instrument having a continuous rolling surface in contact with the paper or other
material, thus giving greater smoothness of action and rendering the motion of the
instrument more uniform and free from jar. Such an instrument produces a more
gentle contact between the pen, pencil, or other marking instrument and the paper;
obviates any snapping or throwing action of the marking device which might
cause blots or blurs upon the drawing and is adapted to more closely and smoothly
follow the edge of French curves and is capable of being used for smaller curves,
(or rather curves of much smaller radius) than is practicable with any other
kind of broken-line instrument with which I am acquainted. Moreover, under my
invention, the broken-line mechanism may form an attachment which may be
clamped to or removed from the pen, pencil, or other marking device of compasses,
beam compasses, ruling instruments and other forms of drawing instruments, without
in any way interfering with the ordinary adjustments of the instrument, or
disturbing its operation.
Under my invention, I provide a sliding piece which may be clamped directly to
the drawing instrument or instruments for which it is intended.
This sliding
piece or carrier is mounted upon or within a handle or frame, but is free to travel
up and down relatively to it. To the frame I secure a contact roller preferably
milled at its edge, to give better grasp upon the paper; and concentrically with
this contact roller or wheel I secure toothed or serrated tripping or actuating
wheels, having peripheries designed to produce the required movement of a tongue
or dog upon the sliding piece or carrier secured to the marking instrument. The
actuating or tripping wheel is of somewhat smaller diameter than the contact
wheel, so that it does not touch the paper; and the frame or handle may be short
enough at its lower end to permit a straight-edge or curve to bear against the
contact wheel or may be long enough to itself form the guide which rests against
the straight-edge or French curve. Preferably, the point of the drawing device
comes as close as possible to the face of the contact wheel where it touches the
paper, thus enabling the draughtsman to guide the instrument against the straight-
edge or curve with much greater ease and precision than is possible where the
marking point trails behind at the end of a vibrating lever, as is common in some
forms of broken-line instruments.
The actuating or tripping wheel is detachable from the contact wheel or roller
so that it may readily be removed and others of a different design substituted.
A pin or a square stud upon the shaft or arbor of the contact roller, interlocking
with the interchangeable actuating wheels, insures the rotation of the latter.

page_text: Such, briefly, is a description of my invention in its broader aspects. Its details
will be better understood by reference to the accompanying drawings which show
two forms of it.
Fig. 1 is a front elevation of an ordinary drawing pen provided with my
attachment.
Fig. 2 is a side elevation of the same.
Fig. 3 is a plan or top view of my attachment showing the clamp by which it is
secured.
Fig. 4 is a view of the frame or handle.
Fig. 5 is a detail view of the tripping or actuating wheel and the clamp with its
.dog or tongue co-operating with the wheel.
Figs. 6 and 7 are respectively edge and face views of the contact roller or
wheel.
my
Fig. 8 shows a sliding cover which forms part of the handle of device.
Fig. 9 shows in side elevation a modification of my device.
Figs. 10 to 13 inclusive are detail views of this modification. And
Fig. 14 shows three designs of tripping or actuating wheels with samples of the
.broken-lines produced by them.
Similar letters of reference throughout the drawings refer to similar parts.
The bar, frame or handle of that form of my device shown in Figs. 1 to 8 is
indicated by A. This is provided with a slot a and a circular perforation for the
stud or shaft that carries the contact roller B. The contact roller or wheel B is
provided with two pins c which fit into and hold the actuating or tripping wheel C.
When the wheel C has been placed in position upon the face of the contact roller B,
a shouldered pin D with a milled nut E may be employed to secure it and the
contact wheel to the frame or handle A.
To the upper part of the frame or bar A is attached a sliding carrier or piece F
(see Figure 3) formed with a tongue e at its lower end for engaging the pro-
jections or teeth of the tripping or actuating wheel C, and provided with a
suitable clamp by which it may be attached to the pen, pencil or other drawing
device with which it is to be used. The piece or carrier F is also provided with
two screws g extending through the slot a of the bar A, and securing it to the bar,
while leaving it free to travel up and down the slot. The lower end of the bar A
may project well below the centre of the roller or contact wheel B to rest against
the edge of the set-square, straight-edge, or French curve used to guide the
instrument; but, of course should not be long enough to touch the paper.
Preferably, however, I form the parts of such shape that the straight-edge or
other guide may rest directly against the contact wheel or roller B as in the
modification hereafter described.
The upper end of the bar A may be formed to fit interchangeably into a longer
handle, or into dividers, beam-compasses, or other instruments, in place of the
usual pen or pencil points; and the lower part may be widened out as shown in dotted
lines in Figure 4 to protect the tripping or actuating wheel C from the fingers. The
roller or contact wheel B is preferably milled on its periphery, to prevent slipping,
and provided with a central Hange around which the wheels C fit.
The projections or teeth on the edge of the tripping or actuating wheel C may
be symmetrically or unsymmetrically shaped. If symmetrical, the instrument may
be run either forward or backward with equal ease; while if unsymmetrical, the
incline upon one side of each tooth being less, the friction between the projections
or teeth and the tongue or dog e will be reduced, but the motion preferably
limited to one direction. The form of wheel shown in Fig. 5 would give a series
of dots equally spaced; other forms will give other lines as clearly shown in Fig. 14.
Any variety of broken lines may therefore be produced by varying the number
shape and size of the teeth and spaces.
The action of the tripping wheel and the tongue or dog e will be readily
understood by those skilled in the art; and the advantages of my sliding action in
place of a vibratory lever will be clearly apparent. When a tooth has raised the

page_text: pen or other marking device from the paper and has passed from beneath the
tongue e, gravity will cause the pen to fall quickly and gently back upon the paper
with a directness and smoothness of action not heretofore attained in any instrument
with which I am acquainted.
In the drawings I have shown my attachment as clamped to an ordinary ruling
pen. The clamp shown is of square form slotted in front to allow the passage of
the adjusting screw of the pen. Against the jaws thus formed the set-screw h
securely clamps the under blade of the pen. To admit placing the pen, pencil or
other marking device at various angles with the plane of the instrument, the
clamp may be made of one or more separate parts and secured to the sliding
carrier F by a spring hinge or universal joint. It will be clearly seen that in any
case the usual adjustments of the pen or other instrument are not in any way
interfered with by the addition of my broken line instrument.
To afford protection to the set screw h and the carrier screws g a sliding cover or
case, as shown in Figs. 3 and 8, may be provided, which, when in place, covers the
screws as shown in Fig. 2.
The modification of my device shown in Figs. 9 to 14, inclusive, is very much
the same in the function and operation of the parts, the chief difference being in the
design and details of the several features. The usual handle of the pen is omitted
and the frame A¹ provided with a handle H. This is of course preferable, as the
usual handle of the pen secured directly to it would move up and down with the pen,
rendering it necessary to hold the instrument by means of the frame or handle A
as already described. In the modification the carrier F1 takes the form of a loose
spool or plug which travels up and down within the frame A', which in this case
forms an enclosing case provided with a slot a". A projection extends from the
carrier F through the slot and forms the clamp or means for attachment to the
pen. The contact wheel or roller B¹ is provided with a rectangular stud b' and a
projecting arbor, or pins, as clearly seen in Fig. 13. The actuating or tripping
wheels C are provided with corresponding rectangular perforations at their centres,
which fit the stud 6' and take the place of the pins c and perforations heretofore
described. The pins, or arbor, of the contact roller B fit on one side into the
hole in the lower end of the frame or case A. At the other side of the wheel
a spring clamp A secured to the case A¹ and provided with a perforated spring
tongue al forms the bearing for the pin or arbor of the contact roller. With this
construction it is only necessary to raise the tongue al and remove together the
wheels B' C; when the actuating wheel may be changed and the parts returned to
their place in order to give any desired form of broken line. In Fig. 9 one of the
great advantages of my invention is especially apparent. The parts are so formed
that the straight-edge rests directly against the contact wheel or roller B¹, and
the point of the pen is immediately beyond it, in the axial plane of the instrument
perpendicular to the line of motion, which is to say, directly at the side of the
wheel B. This enables the draughtsman to employ the instrument with much
greater ease and precision than would otherwise be possible. Indeed many forms
of broken-line instruments with which I am acquainted, are usually employed
only for straight lines, because the manipulation is too difficult or too inaccurate in
curve work.
I have now set forth two modifications of my device. I have purposely omitted
all mention of many other modifications and variations which may be made, both
in the arrangement and in the details of the several parts, because to enumerate
them all would obscure rather than make clear the more essential features of my
invention.

page_text: A New or Improved Instrument for Drawing Broken or
Dotted Lines.
I, JAMES HARMER KNIGHT, of 28 Westview Avenue, Germantown, Phila-
delphia, in the United States of America, Engineer and Draughtsman, 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:
My invention relates to improvements in that class of drawing instruments
employed for making broken lines in which the motion of the instrument, acting
through suitable mechanism raises and drops the pen, pencil, or other marking
device, causing it to form dots, dots and dashes or any other desired form of broken
line, according to the mechanism used. By my invention I am enabled to produce
an instrument having a continuous rolling surface in contact with the paper or
other material, thus giving greater smoothness of action and rendering the motion
of the instrument more uniform and free from jar. Such an instrument produces
a more gentle contact between the pen, pencil, or other marking instrument and
the paper; obviates any snapping or throwing action of the marking device which
might cause blots or blurs upon the drawing and is adapted to more closely and
smoothly follow the edge of French curves and is capable of being used for smaller
curves, (or rather curves of much smaller radius) than is practicable with any
other kind of broken-line instrument with which I am acquainted. Moreover,
under my invention, the broken-line mechanism may form an attachment which
may be clamped to or removed from the pen, pencil, or other marking device of
compasses, beam compasses, ruling instruments and other forms of drawing
instruments, without in any way interfering with the ordinary adjustments of the
instrument, or disturbing its operation.
Under my invention, 1 provide a sliding piece which may be clamped directly to
the drawing instrument or instruments for which it is intended. This sliding piece
or carrier is mounted upon or within a handle or frame, but is free to travel up
and down relatively to it. To the frame I secure a contact roller preferably milled
at its edges, to give better grasp upon the paper; and concentrically with this
contact roller or wheel I secure toothed or serrated tripping or actuating wheels,
having peripheries designed to produce the required movement of a tongue or dog
upon the sliding piece or carrier secured to the marking instrument. The actuating
or tripping wheel is of somewhat smaller diameter than the contact wheel, so that
it does not touch the paper; and the frame or handle may be short enough at its
lower end to permit a straight-edge or curve to bear against the contact wheel or
may be long enough to itself form the guide which rests against the straight-edge
or French curve. Preferably, the point of the drawing device comes as close as
possible to the face of the contact wheel where it touches the paper, thus enabling
the draughtsman to guide the instrument against the straight-edge or curve with
much greater ease and precision than is possible where the marking point trails
behind at the end of a vibrating lever, as is common in some forms of broken-line
instruments.
The actuating or tripping wheel is detachable from the contact wheel or roller
so that it may readily be removed and others of a different design substituted.
A pin or a square stud upon the shaft or arbor of the contact roller, interlocking
with the interchangeable actuating wheels, insures the rotation of the latter.
Such, briefly, is a description of my invention in its broader aspects. Its details
will be better understood by reference to the drawings left with the Provisional
Specification which show two forms of it.

page_text: Fig. 1 is a front elevation of an ordinary drawing pen provided with my
attachment.
Fig. 2 is a side elevation of the same.
Fig. 3 is a plan or top view of my attachment showing the clamp by which it is
secured.
Fig. 4 is a view of the frame or handle.
Fig. 5 is a detail view of the tripping or actuating wheel and the clamp with its
dog or tongue co-operating with the wheel.
Figs. 6 and 7 are respectively edge and face views of the contact roller or wheel..
Fig. 8 shows a sliding cover which forms part of the handle of my device.
Fig. 9 shows in side elevation a modification of my device.
Figs. 10 to 13 inclusive are detail views of this modification. And
Fig. 14 shows three designs of tripping or actuating wheels with samples of the
broken-lines produced by them.
Similar letters of reference throughout the drawings refer to similar parts.
The bar, frame or handle of that form of my device shown in Figs. 1 to 8 is.
indicated by A. This is provided with a slot a and a circular perforation for the
stud or shaft that carries the contact roller B. The contact roller or wheel B.
is provided with two pins c which fit into and hold the actuating or tripping wheel C.
When the wheel C has been placed in position upon the face of the contact roller B,
a shouldered pin D with a milled nut E may be employed to secure it and the
contact wheel to the frame or handle A.
To the upper part of the frame or bar A is attached a sliding carrier or piece F
(see Figure 3) formed with a tongue e at its lower end for engaging the projections.
or teeth of the tripping or actuating wheel C, and provided with a suitable clamp f
by which it may be attached to the pen, pencil or other drawing device with which it.
is to be used. The piece or carrier F is also provided with two screws g extending
through the slot a of the bar A, and securing it to the bar, while leaving it free to
travel up and down the slot. The lower end of the bar A may project well below
the centre of the roller or contact wheel B to rest against the edge of the set-square,.
straight-edge, or French curve used to guide the instrument; but, of course it
should not be long enough to touch the paper. Preferably, however I form the
parts of such shape that the straight-edge or other guide may rest directly against
the contact wheel or roller B as in the modification hereafter described.
The upper end of the bar A may be formed to fit interchangeably into a longer
handle, or into dividers, beam-compasses, or other instruments, in place of the usual
pen or pencil points; and the lower part may be widened out as shown in dotted
lines in Figure 4 to protect the tripping or actuating wheel C from the fingers.
The roller or contact wheel B is preferably milled on its periphery, to prevent
slipping, and provided with a central flange around which the wheels C fit.
The projections or teeth on the edge of the tripping or actuating wheel C may
be symmetrically or unsymmetrically shaped. If symmetrical, the instrument may
be run either forward or backward with equal ease; while if unsymmetrical, the
incline upon one side of each tooth being less, the friction between the projections
or teeth and the tongue or dog e will be reduced, but the motion preferably limited
to one direction. The form of wheel shown in Fig. 5 would give a series of dots.
equally spaced; other forms will give other lines as clearly shown in Fig. 14. Any
variety of broken lines may therefore be produced by varying the number, shape
and size of the teeth and spaces.
The action of the tripping wheel and the tongue or dog e will be readily under-
stood by those skilled in the art, and the advantages of my sliding action in place
of a vibratory lever will be clearly apparent. When a tooth has raised the pen or
other marking device from the paper and has passed from beneath the tongue e,
gravity will cause the pen to fall quickly and gently back upon the paper with a
directness and smoothness of action not heretofore attained in any instrument with
which I am acquainted.
In the drawings I have shown my attachment as clamped to an ordinary ruling

page_text: .
pen. The clamp shown is of square form slotted in front to allow the passage of
the adjusting screw of the pen. Against the jaws thus formed the set-screw h
securely clamps the under blade of the pen. To admit placing the pen, pencil or
other marking device at various angles with the plane of the instrument, the clamp f
may be made of one or more separate parts and secured to the sliding carrier F by
a spring hinge or universal joint. It will be clearly seen that in any case the
usual adjustments of the pen or other instrument are not in any way interfered
with by the addition of my broken-line instrument.
To afford protection to the set-screw h and the carrier screws g a sliding cover or
case, as shown in Figs. 3 and 8, may be provided, which, when in place, covers the
screws as shown in Fig. 2.
The modification of my device shown in Figs. 9 to 14, inclusive, is very much
the same in the function and operation of the parts, the chief difference being in the
design and details of the several features. The usual handle of the pen is omitted
and the frame A¹ provided with a handle H. This is of course preferable, as the
usual handle of the pen secured directly to it would move up and down with the
pen, rendering it necessary to hold the instrument by means of the frame or
handle A as already described. In the modification the carrier F¹ takes the form
of a loose spool or plug which travels up and down within the frame A', which in
this case forms an enclosing case provided with a slot a". A projection f¹ extends
from the carrier F1 through the slot and forms the alama or
www pett.
The contact wheel or roller B is provided with a rectangular stud bl
and a projection arbor, or pins, as clearly seen in Fig. 13. The actuating or
tripping wheels C are provided with corresponding rectangular perforations at their
centres, which fit the stud and take the place of the pins c and perforations
heretofore described. The pins, or arbor, of the contact roller B¹ fit on one side
into the hole in the lower end of the frame or case A¹. At the other side of
the wheel a spring clamp A" secured to the case A¹ and provided with a perforated
spring tongue a forms the bearing for the pin or arbor of the contact roller. With
this construction it is only necessary to raise the tongue al and remove together
the wheels B, C, when the actuating wheel may be changed and the parts returned
to their place in order to give any desired form of broken line. In Fig. 9 one of
the great advantages of my invention is especially apparent. The parts are so
formed that the straight-edge rests directly against the contact wheel or roller B¹,
and the point of the pen is immediately beyond it, in the axial plane of the
instrument perpendicular to the line of motion, which is to say, directly at the side
of the wheel B. This enables the draughtsman to employ the instrument with
much greater ease and precision than would otherwise be possible. Indeed many
forms of broken-line instruments with which I am acquainted, are usually employed
only for straight lines, because the manipulation is too difficult or too inaccurate in
curve work.
I have now set forth two modifications of my device. I have purposely omitted
all mention of many other modifications and variations which may be made, both in
the arrangement and in the details of the several parts, because to enumerate them
all would obscure rather than make clear the more essential features of my
invention.
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. The new or improved instrument for drawing broken or dotted lines
substantially as set forth.
2. In an instrument for drawing broken or dotted lines, the combination of a
roller or contact wheel, a suitably formed and removable actuating wheel, a pen,
pencil or other marking device, and a mechanical transmitting mechanism by which
the rotary motion of the said removable actuating wheel produces a reciprocating
motion of the said marking device substantially as set forth.

page_text: 3. In an instrument for drawing broken or dotted lines, the employment of a
tripping or actuating wheel and a sliding carrier substantially as and for the
purpose set forth.
4. The arrangement and combination of parts substantially as set forth with
reference to Figures 1 to 8 inclusive.
5. The arrangement and combination of parts substantially as set forth with
reference to Figures 9 to 13 inclusive.
Dated this 25th day of March 1896.
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Chartered Patent Agent.