Improvements in the Locking and Unlocking of Drawing Compasses.
Year: 1899

page_text: Date of Application, 22nd July, 1899
Comptata On
PROVISIONAL SPECIFICATION.
Improvements in the Locking and Unlocking of Drawing Compasses.
We, GEORGE TUCKER, of Dartmouth Street Works, Birmingham, Warwick-
shire, General Stamper, Eyelet and Paper Fastener Manufacturer, and GEORGE
Daws, of 252, Nechells Park Road, Birmingham, in the County of Warwick-
shire, Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to that kind of drawing compasses formed by an ordinary
compass leg formed of steel or any other suitable material to a barrel shaped clip
formed to receive an ordinary cedar or other kind of pencil and which at the
same time that it grips the pencil firmly, allows it to be moved upwards or down-
wards in it; the pencil thus forming one leg of the compasses.
The invention relates however more particularly to the improved method of
clamping or locking the legs of the compasses in any required position, the
simplicity of construction enabling it to be placed on the market at a much
cheaper rate than hitherto,
In manufacturing this invention we make the pencil clip in the following
way: Taking a sheet of metal blank we turn it into a barrel shaped socket so as
to grasp the pencil: from this socket two semicircular pieces are cut and on
being turned back, form the cheeks in which the metal leg moves.
these cheeks a small rib is formed rising slightly above the ordinary surface
On one of
and extending for about a quarter of a circle at the bottom portion.
A small stud moves close over the ordinary surface of the check, the shank
of which passes through the two cheeks and leg thus forming the pivot upon
which the legs move: the shank after passing through a small spring is rivetted
ufficiently tight to allow the stud to be turned. By turning the stud so that
t is in a parallel position to the pencil one of the projections will have passed
nto the rib, thereby causing the cheeks to be clamped closely together thereby
ocking the legs in position.
Sometimes however we make the barrel clip and checks in two portions; half
he barrel and one cheek in each piece (and in this case the barrel is not
ut to supply the cheek pieces): the two halves are then laid together, and two
oles punched through, the burr on the other side then being clinched and
vetted down. The raised rib is formed as before mentioned, and the stud fixed
the same way:
Dated this 5th day of I…]..
1000

page_text: Improvements in the Locking and Unlocking of Drawing Compasses.
We, GEORGE TUCKER, of Dartmouth Street Works, Birmingham, Warwick-
shire, General Stamper, Eyelet and Paper Fastener Manufacturer, and GEORGE
Daws, of 252, Nechells Park Road, Birmingham, in the County of Warwick-
shire, Civil Engineer, 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 that kind of drawing compasses formed by an ordinary
compasses leg of steel or other suitable material jointed to a barrel shaped clip
formed to receive and grip an ordinary cedar or other kind of pencil movable
along the clip and thus forming one leg of the compasses. This invention
consists of the herein described improved means for clamping or locking the
legs of the compasses in any required position. the simplicity of construction
enabling it to be manufactured very cheaply.
We will describe this invention by referring to the accompanying drawings on
which Fig. 1 is a side elevation of drawing compasses with our invention applied;
Fig. 2 is a plan of the same; (Figs. 1 and 2 shew the compasses legs unlocked)
Fig. 3 is a front elevation and Fig. 4 is a side elevation of the same compasses
the legs being represented as locked; Fig. 5 shews the clip part of the com-
passes separately; Fig. 6 represents a sheet metal blank from which the clip
is formed; Fig. 7 is a separate view of the locking stud part of the said com-
passes; Fig. 8 shews the top portion of the ordinary leg of the compasses; Fig. 9
is a side elevation of a modified form of the clip; Fig. 10 is a plan of the clip
shewn in Fig. 9; and Fig. 11 shews the sheet metal blank from which the clip
represented in Figs. 9 and 10 is formed.
The same letters of reference indicate the same or corresponding parts in all
the figures.
In carrying out this invention we take a sheet metal blank preferably of the
shape shewn by Fig. 6 and we bend the portions a² around to form the necessary
barrel shaped socket to grip the pencil B. From this socket two almost circular
pieces are cut and bent back to form the two cheeks between which the
metal leg C moves. On the check at a small rib is raised slightly above the
surface and at a certain distance from the central hole a and extends for about
a quarter of the circle more or less. This rib is as shewn in Fig. 2 slightly
inclined that is to say it rises gradually to the wider end a. 1) is the joint stud
which passes through the hole a in the two cheeks and through the hole ¹ in the
leg and this stud has two side projections marked respectively and this
stud 1 has a flanged head which is gripped between the thumb and finger.
The said stud has two side projections marked respectively one of which
namely bears upon the check at and the other side projection rides upon
the outwardly projecting riba. After the stud 1) has passed through the hole a
in the cheeks in the leg it also passes through a washer E and the end d
is rivetted over sufficiently to allow the stud D to turn.
By turning the stud D so that it is in a position about parallel with the pencil
as shewn in Fig. 3 the projection will have passed on to the rib whilst the
other projection bears upon the check at thus causing the cheeks at a to be
closely clamped against the sides of the leg C thereby firmly locking the leg to
the clip. To unlock the leg so that it can be set with its end at any required
distance from the end of the pencil B the stud D has to be turned to such a
position as represented by Fig. 1, so that it does not ride upon the inclined rib a³

page_text: thus releasing the pressure of the cheeks a³ at on the leg C and allowing of the
same to be turned and set as required.
Instead of making the clip barrel part a¹ a² in a piece with the cheeks a³ at as
above described and represented by Figs. 1, 2, 3, 4, 5 and 6, we may make the
said combined barrel and cheeks in two pieces as shewn for instance by Figs. 9, 10
and 11 where it will be seen that one half, in this case marked a", of the barrel
and one cheek at are made of one piece of metal and the other half of the
barrel and the other cheek are made of another piece of metal such for
instance as represented by Fig. 10 and after the two parts have been raised so
that they meet together at a between the barrel and the hole for the stud
the two parts are there fixed together as by the rivets ff passing through the
two blanks as shewn in Figs. 9 and 10. It will be seen that in this arrange-
ment as in the first above described the cheek a has the raised rib and the
leg is similarly clamped between the cheeks by the stud D) which is fixed to
the clip in the same manner as above described with reference to Figs. 1 to 8
both inclusive.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is:
-
In combination in drawing compasses, the barrel adapted to grip a pencil,
the cheeks a secured to the said barrel one of said checks having an inclined
rib on the outer side, the compasses leg fitting between the said cheeks and
a stud I passing through the checks and leg and made with side projections to
bear on the rib and on the cheek and so arranged that when the stud is turned
in one direction it bears upon the inclined rib and clamps the cheeks and the
leg together and when the stud is turned in the opposite direction the leg is
free, all substantially as described.
Dated this 21st day of April 1900.
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.