IMPROVEMENTS IN STRAIGHT-LINE DIVIDING ENGINES AND TOOLS REGULATING DISTANCES
Year: 1865

page_text: LETTERS PATENT to William Ford Stanley, Mathematical Instrument
Maker, of 3, Great Turnstile, Holborn, London, for the Invention of
"IMPROVEMENTS IN STRAIGHT-LINE DIVIDING ENGINES AND TOOLS
REGULATING DISTANCES."
Sealed the 31st October 1865, and dated the 4th May 1865.
COMPLETE SPECIFICATION filed by the said William Ford Stanley at the
Office of the Commissioners of Patents, with his Petition and Decla-
ration, on the 4th May 1865, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
FORD STANLEY, Mathematical Instrument Maker, of 3, Great Turnstile,
Holborn, London, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
STRAIGHT-LINE DIVIDING ENGINES AND TOOLS FOR REGULATING DISTANCES," and
have petitioned Her Majesty to grant unto me, my executors, administrators,
and assigns, Her Royal Letters Patent for the same, and have made solemn
Declaration that I am the true and first Inventor thereof.

page_text: NOW KNOW YE, that I, the said William Ford Stanley, do hereby
declare that the following Complete Specification under my hand and seal
fully describes and ascertains the nature of the said Invention, and in what
nanner the same is to be performed, in and by the following statement:--
My Invention consists of three improvements, which are all applicable to
the straight-line dividing engine; they are applied to different portions of the
engine, and may be used either connectedly or separately. The dividing
engine is used for producing the divisions upon scales, rules, or other pur-
poses which require consecutive lines at equal or proportional spaces.
My first improvement consists in a new system of regulating these distances
or spaces of division. The system will be shown more clearly by first briefly
describing the manner by which it is accomplished by the ordinary straight-
line dividing engine, which consists of a screw of known pitch placed longi-
tudinally and parallel within a bed similar to a lathe bed; the screw carries a
slide along the bed, which slide carries the dividing knife along the scale,
which is clamped to a portion of the bed; the screw is moved the required
revolutions or portion of a revolution by a divided disc or equivalent apparatus
placed at the end of it.
My first improvement consists in placing the screw upon an axis so that
it may work obliquely between the bed instead of working parallel with the
bed, or what would be the same mechanical equivalent, centring the bed to
move to any degree of obliquity or angle to the screw.
In the accompanying Drawing, Fig. 1, I have shewn the screw centred
near one end of it (marked centre) and placed obliquely between the bed
I, I, I. At the opposite end of the screw to the centre or axis I place a
divided are which exactly indicates the degree of obliquity of the screw to the
bed. The carriage or slide F, F, which moves along the bed to carry the
dividing knife takes its motion from the screw by the nut N, which has a
rocking centre C and is fitted to a slide E which moves along the transverse
bed D, D. It will be readily seen by the above that this will admit free
revolution of the screw although working obliquely to the bed. The above
construction merely shows the system, the details of which might be con-
siderably varied with the same equivalent mechanical effect, as, for instance,
instead of the knife being carried along the scale the scale might be carried
on the slide and the knife remain stationary, or other similar variations of
detail. The intention of this improvement is to introduce an oblique acting
instead of a parallel acting screw, the effect of which is, that the value of the
revolution of the screw may be regulated by the obliquity of it; thus, for
instance, if we place the screw at d, which is about parallel with the bed, we

page_text: may suppose ten revolutions of the screw will carry the slide F one inch;
then, if the screw. be moved obliquely to e, it will take about fourteen revo-
lutions to carry the slide F, and consequently the dividing knife, one inch;
or, for instance, letione revolution of the screw at S be the tenth of an English
inch, then one revolution of the screw at B will be the tenth of a Baden inch,
which is shorter than the English inch; or one revolution of the screw fixed
at A will be the tenth of an Austrian inch, which is longer than the English
inch. The system of this improvement: admits of dividing any scale to perfect
standard of any country, although the pitch of the screw bears no simple
fractional proportion to the scalo.
I also claim this improvement if employed to dividing or regulating me-
chanical spaces, as, for instance, applied to lathes for cutting the threads of
screws or similar purposes.
My second improvement consists in the means. I employ to render the
action of dividing engines continuous or self-acting. This I accomplish by
the employment of a ratchet wheel to give motion to the screw, the teeth of
which being equally divided and cut, take the place of a divided disc or its
equivalent in the ordinary engine. The principle of the action of the ratchet
is shown in the accompanying Drawing at Fig. 2. The ratchet wheel R is
moved by the paw! P. The pawl is carried by a lever Q, one end of which
has an axis upon the same centre as the ratchet wheel. The lever Q takes
its motion from a moveable eccentric centre U, the true centre of which is
at f; by the setting of the eccentric centre U upon the slide T any required
number of teeth may be taken by the lever and pawl. By the number of
teeth that the pawl takes the screw of the engine is moved some required.
proportion of its revolution. Motion may be given to the eccentric by any
simple mechanical means, and by this motion the screw will carry a slide
continuously, stopping at calculated distances to represent spaces of division,
and this it will do with any required velocity.
The third improvement consists in self-acting means of regulating the
lengths of the lines or readings, as they are called, of the divisions upon scales.
This is shewn at Fig. 3 of the accompanying Drawings. In this improvement
the knife, which is shown detached at 9, is caused to pass out given distances
upon the scale according with the sizes of the teeth in the detent wheel V.
This is effected in the following manner :-The lever a, a, is caused to reci-
procate upon its axis h by a crank or other simple mechanical means; the
lever carries with its action a slide b, b, upon which is jointed a falling
catch W; this catch by the reciprocating action of the lever brings forward
with each stroke one tooth of the detent wheel V until it is stopped by the.

page_text: hook detent X (which is colored dark to show its action clearly). To allow
the catch W to bring forward a second tooth the detent X has to be raised
by the back action of the slide b, b; this may be accomplished by a lever, or,
as shown in the Drawing, by an incline and stud; Z, the incline; Y, the stud.
It will be seen by the Drawing that when the lever a brings the incline back
to the stud the stud will commence to slide up the incline, which will draw
With the
the detent X above the tooth of the wheel and allow it to pass.
return action of the lever the detent X will fall in time to detain the next
tooth, which will be brought forward by the catch W. From the above
description it will be seen that if the tooth of the detent wheel be large the
lever will only carry the dividing knife a short distance upon the scale to be
divided, consequently it will make a short division or line. If the tooth taken
be small the knife will pass out a greater distance upon the scale, and con-
sequently make a long line to indicate the tens, twelves, or principal lines
upon the scale according with the number and sizes of the teeth in the detent
wheel.
What
The above description contains the principle of my improvements. I am
quite aware that the detail of construction may be much varied to produce
the same results. Indeed I have shewn the principles in the simplest way
I could conceive to avoid confusion as to the ideas which they represent; for
the same reason I have not shewn the mechanical connections which would
cause these parts to work in unity because they could be readily conceived by
any intelligent mechanic, and would much tend to confuse the illustration of
my improvements. For instance, it is very indifferent whether an engine of
this class be worked by a treddle, a handle, or by steam power; it is also
indifferent whether the action be direct upon the screw or through pulleys
or cog wheels which might be used to vary the multiplying power.
I claim as my Invention is the simple separate principles of action of the
above improvements, either of which may be applied to dividing engines. It
is furthermore the use of these improvements that I particularly claim, as the
value of an engine which unites all these improvements is merely nominal,
except the use of it as a tool to produce scale division. I am quite aware
that some of the details of my improvements have been employed for other
mechanical purposes, particularly the second improvement, which I only claim
as my Invention in relation to dividing engines; some other parts are familiar
mechanical detail. Thus what I particularly claim as my Invention is,―
1st, an oblique-acting screw for regulating distances.
2nd, propelling the screw of straight line dividing engines by means of a
ratchet, pawl, and eccentric.

page_text: 3rd, a detent wheel and detent, the teeth of the wheel to regulate the
lengths of lines in dividing.
In witness whereof, I, the said William Ford Stanley, have hereunto set
my hand and seal, this Fourth day of May, in the year of our Lord
One thousand eight hundred and sixty-five.
W. FORD STANLEY. (L.S.)