Improvements in Drawing Compasses.
Year: 1895

page_text: Improvements in Drawing Compasses.
We, ALFRED HAVILAH WOODWARD of Legge Lane, in the City of
Birmingham, Manufacturer, and FREDERICK ADDISON WILLMOTT of 186 Wind-
mill Lane, Smethwick, near Birmingham aforesaid, Tool Maker, do hereby declare
the nature of this invention to be as follows:-
:-
This invention relates to drawing compasses, principally used by children in
school, but which are applicable to ordinary compasses, and has for its object a
simple and efficient means for both holding and adjusting the pencil within the
holder, which may consist of a barrel or frame carried at the end of the short leg
of a compass.
Our invention consists in providing the inside bore of the holder with a quick
running and inwardly projecting helix or part helix, so formed as to impress itself
into the wood or material of the pencil to be held, which said pencil is rotated for
adjustment.
In carrying out one form of our improvements, we take an ordinary compass
with the short leg fitted at its end with a barrel or holder preferably directed at an
angle to the said short leg and with its bore or inside surface provided with a
quick threaded helix or part of a helix projecting inwardly and adapted to impress
itself into the wood or material of a lead pencil.
The inside bore of the holder or barrel is of the same size and diameter as the
pencil, so that when a pencil is introduced into the holder and then rotated, the
worm imbeds itself into the wood and forms therein a corresponding and helical
impressed channel or groove and the pencil is adjusted by the propelling and
repelling action of the worm on the said pencil being turned one way or the other.
The pencil is kept perfectly rigid and can only advance or retire by its being
rotated.
We wish it to be understood that we do not confine ourselves to the pitch of the
helix, worm or equivalent, as the slower the pitch of the helix the slower and finer
is the adjustment.
We prefer to inwardly impress or crease the metal of the holder to form the
helix, but to this we do not confine ourselves as the said helix may be cut or formed
from the inside walls of the bore of the holder.
As a modification, the helix or part helix may be made by cutting the barrel
oblique and pressing the pierced bit inwards, thereby forming a part cutting helix,
which cuts its way into the wood helically as the pencil is rotated.
In practice we find sufficient binding and impressing power is attained by a part
helix.
As a further form of our improvements we may apply to the inside of an
ordinary barrel, an attached or fitted worm or helix or cutting worm, rib or other
helical formation.
We prefer to make the holder from thin sheet metal with the helix indented
inwards by outwardly applied pressure run worm or screw-wise around the barrel,

page_text: but we may if necessary make the same from a coil of wire, with the inside of the
wire formed with impressing edges.
Dated this 19th day of November 1895.
WIES Cpasses.
We, ALFRED HAVILAH WOODWARD of Legge Lane, in the City of
Birmingham, Manufacturer, and FREDERICK ADDISON WILLMOTT of 186 Wind-
mill Lane, Smethwick, near Birmingham aforesaid, Tool 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 :-
This invention relates to drawing compasses, principally used by children in
school, but which are applicable to ordinary compasses, and has for its object a
simple and efficient means for both holding and adjusting the pencil within the
holder, which may consist of a barrel or frame carried at the end of the short leg
of a compass.
Our invention consists in providing the inside bore of the holder with a quick
running and inwardly projecting helix or part helix, so formed as to impress itself
into the wood or material of the pencil to be held, which said pencil is rotated for
adjustment.
In carrying out one form of our improvements, we take an ordinary compass
with the short leg fitted at its end with a barrel or holder preferably directed at
an angle to the said short leg and with its bore or inside surface provided with a
quick threaded helix or part of a helix projecting inwardly and adapted to impress
itself into the wood or material of a lead pencil when the said pencil is rotated.
The inside bore of the holder or barrel is of about the same size and diameter
as the pencil, so that when a pencil is introduced into the holder and then rotated,
the worm imbeds itself into the wood and forins therein a corresponding and helical
impressed channel or groove and the pencil is adjusted by the propelling and
repelling action of the worm on the said pencil being turned one way or the other.
The pencil is kept perfectly rigid and can only advance or retire by its being
rotated.
We wish it to be understood that we do not confine ourselves to the pitch of the
helix, worm or equivalent as the slower the pitch of the helix the slower and finer
is the adjustment and in order to accommodate different sized pencils, the barrel
may be longitudinally split and if necessary, the split barrel may be reinforced by
a split sheath.
Figure 1 of the accompanying drawing represents a pencil compass with the
pencil holder or barrel made according to one form of my invention.
Figure 2 represents a front elevation of the compass.
Figure 3 represents, upon an enlarged scale, the barrel with pencil therein and a
part of the short leg of the compass.
Figure 4 is a vertical section of Figure 3 and Figure 5 a cross section of the
same upon the dotted line x.
The same letters of reference indicate corresponding parts in Figures 1 to 5.
a is the compass, having a long leg a', and a short leg a², to which is fixedly
attached the barrel b, having an inwardly projecting impressed helix or worm b¹,

page_text: with an inside diameter less than that of the bore of the barrel, so as to form as it
were a quick-running screw which impresses itself into the external surface c', of
the soft wood of a pencil c, when the said pencil has imparted to it a rotatory
motion.
Thus, by putting the tip end of a lead pencil into the barrel, and pressing forward
and rotating the same, the thread leads and draws the same forward, whereby the
lead is held rigid when not rotated and is adjusted when rotated.
We prefer to inwardly impress or crease the metal of the holder to form the
helix, but to this we do not confine ourselves as the said helix may be cut or formed
from the inside walls of the bore of the holder.
As a modification, the helix or part helix may be made by cutting the barrel
oblique and pressing the pierced bit inwards, thereby forming a part cutting helix,
which cuts its way into the wood helically as the pencil is rotated.
In practice we find that sufficient binding and impressing power is attained by
such a part helix.
and
Figure 6 represents a pencil compass constructed according to this modification
Figure 7 is a cross section of Figure 6 upon the dotted line x¹.
a² is the short leg of the compass and 6 is the barrel made fast to it and b' is a
part helical rib or part helix impressed or cut out from the metal of the holder and
with the said impressed or cut out part projecting inwards or standing away from
the inside bore of the barrel.
c is the pencil, which is held in the holder by the said rib, and when rotated is
propelled and repelled for adjustment within the same.
As a further form of our improvements we may apply to the inside of an
ordinary barrel, an attached or fitted worm or helix or cutting worm, rib or other
helical formation.
We prefer to make the holder from thin sheet metal with the helix indented
inwards by outwardly applied pressure run worm or screw-wise around the barrel.
Figure 8 is another modification of our improvements in which the helically
inside ribbed barrel or holder is split or reinforced by a sheath, so that the said
holder is laterally adjustable in order to be capable of taking varying sized pencils
within certain limits.
Figure 9 is a cross section of Figure 8 upon the dotted lines r² showing the
component parts forming the barrel.
Figure 10 represents the split holder without the sheath.
Figure 11 is an elevation of the sheath separately and Figure 12 a section of
the same.
Figure 13 is a front elevation of Figure 10 and Figure 14 is a section upon the
dotted lines, Figure 13.
Figure 15 is a vertical section of Figure 8, with the pencil removed.
In Figures 8 to 15, a' is the short leg of a compass, having attached to it a
longitudinally split barrel b, whose inside bore is helically ribbed at 6', for the
purpose of holding and adjusting the pencil c, but being split, it is capable of taking
various sized pencils within certain limits. d is a split and plain sheath which
springs over the split helical barrel and reinforces its sides or walls and contracts
and keeps the same tight home upon the surface of the lead pencil with sufficient
force to cause the helical rib to impress itself into the wood.
When the split barrel is made from sheet steel or other stout metal, the
reinforcing sheath may be dispensed with.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
--
First. In pencil drawing compasses, the combination with the leg of a compass,
of a barrel or pencil holder, whose bore is helically ribbed or partly helically
ribbed, substantially as and for the purpose as described and set forth.

page_text: Secondly. In pencil drawing compasses, the combination with the leg of a
compass, of a split barrel or pencil holder whose bore is helically ribbed or partly
helically ribbed, substantially as and for the purpose described and set forth.
Thirdly. In pencil drawing compasses, the combination with the leg of a
compass having a split and helically-ribbed pencil holder, of a plain and split
sheath, substantially as and for the purpose described and set forth in Figures 8
to 15.
Dated this 22nd day of June 1896.
ALFRED HAVILAH WOODWARD,
FREDERICK ADDISON WILLMOTT,
By Henry Skerrett,
24 Temple Row, Birmingham, Agent for Applicants.