IMPROVEMENTS IN DRESSING MILLSTONES AND IN APPARATUS TO BE USED THEREFOR
Year: 1869

page_text: LETTERS PATENT to William. Huggins, of Halstead, in the County
of Essex, and Henry Horanaill, of Bulford Mills, near Witham,
in the said County, for the Invention of "IMPROVEMENTS IN DRESSING
MILLSTONES AND IN APPARATUS TO BE USED THEREFOR."
Scaled the 16th July 1860, and dated the 23rd January 1809.
PROVISIONAL SPECIFICATION left by the said William Huggins and
Henry Horsnaill at the Office of the Commissioners of Patents, with
their Petition, on tho 25rd January 1869.
We, WILLIAM HUGGINS, of Halstead, in the County of Essex, and
HENRY HORSNAILL, of Bulford Mills, near Witham, in the said County,
do hereby declaro the nature of the said Invention for "IMPROVEMENTS
IN DRESSING MILLSTONES AND IN APPARATUS TO BE USED THEREFOR," to be as
follows:-
This Invention consists in certain improvements which are especially
applicable to the use of diamonds or other hard stones for dressing
millstones.
An important feature in this Invention consists in making the
"cracks" or "dress" of the stones in segments of a circle instead of in

page_text: the usual rectilinear direction up or down the lands or grinding surfaces
of the millstones. The "cracks" or "dress" may consist of a series of
continuous segmental curves from the eye or centre of the stone to the
periphery, which method is by preference adopted, or may consist of two
several concentric series of such curves.
The machinery employed for the purposes of this Invention is as
follows: A central upright shaft the foot of which works in a step
bearing, placed by preference in or near to the centre of the millstone, is
arranged so as to work at the top on a fixed centro point. To the lower
part of the upright shaft is fixed a double arm in the form of a triangle,
the same being adjusted by set screws. A driving pulley is attached to
a spur wheel by a sleeve or socket fitted to revolve on the upright shaft.
A second spur wheel works in the last-mentioned wheel, and the spindle
of the former passing through one end of the double arm or triangle
gives motion to a crank below the same. The diamond or other tool is
carried by an arm and lever, the same having a centre spindle which is
fitted into a proper bearing in the opposite end of the double arm or
triangle and is connected by a connecting rod with the before-mentioned
crank and receives from it a reciprocating motion. A worm wheel is
fitted and fixed into a step bearing, a screw fixed in bearings on the
under side of the double arm working into the same, one end of such
screw having a ratchet wheel to which motion is given by a click worked
by a stud on the boss of the crank. The diamond or other tool is made
of a triangular form, and works in a slot fitted for the same in the tool
holder in the manner of a slide rest on the end of the reciprocating arm
or lever, the top of the diamond or other tool being screwed. The depth
of cut is adjusted by a socket nut fitted in the top of the tool holder. If
preferred the tool holder is fixed on a centre in the manner of a planing
machine, so that by an adjusting set screw the diamond or other cutting
stone may be made to cut lightly in going in or out, and deeper in the
return cut when the machine is set to cut both ways in the same
"crack."
The mode of working the machine is as follows:-Motion is given
by means of a cord or band to the pulley and spur wheel on the
upright shaft, causing the crank to revolve. The diamond or other
cutting stone is set down to the required depth of cut, and cuts in and
out of the same "crack," the stud on the boss of the crank giving
one notch motion to the ratchet wheel and screw, thus making the
inachine revolve the distance of one "crack," or by an additional stud

page_text: or crank boss the machine may be made so as to enable it to cut two
"cracks" on each revolution of the crank. Any suitable motive power
may be employed.
SPECIFICATION in pursuance of the conditions of the Letters Patont,
filed by the said William Huggins and Henry Horsnaill in the Great
Seal Patent Office on the 23rd July 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, WILLIAN
IIUGGINS, of Halstrad, in the County of Essex, and HENRY HORSNAILL,
of Bulford Mills, near Witham, in the said County, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of January, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Huggins and Henry Horsnaill,
Her special licence that we, the said William Huggins and Henry
Horsnaill, our executors, administrators, and assigns, or such others as
we, the said William Huggins and Henry Horanaill, our executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN DAROWING
MILLSTONES AND IN APPARATES TO BE USED TREKKPOR," upon the condition
(amongst others) that we, the said William Huggins and Henry Horanaill,
our executors or administrators, by an instrument in writing under
us, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the
Great Seal Patout Office within six calendar months next and imme-
diately after the date of the said Letters l'atent.
NOW KNOW YE, that we, the said William Huggins and Heury
Horanaill, do hereby declare the nature of our said Invention, and in
Awhat manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
Our said Invention has special reference to dressing millstones by

page_text: means of diamonds or other hard substances, and an important feature
in this Invention consists in making the "cracks" or "dress" of the
stones in segments of a circle instead of in the usual rectilinear direction
up or down the lands or grinding surfaces of the millstones. The
"cracks" or "dress may consist of a series of continuous segmental
curves from the eye or centre of the stone to the periphery, which
method is that we prefer to adopt, but two several concentric series of
such curves may be used when thought desirable.
The machinery employed for the purposes of this Invention consists
of a central upright shaft the foot of which works in a step bearing,
placed by preference in or near to the centre of the millstone, arranged
- so as to work at the top on a fixed centre point. To the lower part of
the upright shaft is fixed a double arm in the form of a triangle, the
same being adjusted by set screws. A driving pulley is attached to a
spur wheel by a sleeve or socket fitted to revolve on the upright shaft.
A second spur wheel works in that last-mentioned wheel, and the spindle
of the former passing through one end of the double arm or triangle
gives motion to a crank below the same; or the arrangements shown by
the Drawings and hereafter described may be substituted for those just
described. The diamond or other tool is carried by an arm and lever,
the same having a centre spindle which is fitted into a proper bearing
and receives a reciprocating motion. A worm wheel is fitted and fixed
into a step-bearing, a screw fixed in bearings on the under side of the
double arm working into the same, one end of such screw having a
ratchet wheel to which motion is given by a click worked by a stud on
the boss of the crank. The diamond or other tool is made of a triangular
form by preference, and works in a slot fitted for the same in the tool
holder in the manner of a slide rest on the end of the reciprocating arm
or lever, the top of the diamond or other tool being screwed. The
depth of cut is adjusted by a socket nut fitted in the top of the tool
holder. If preferred the tool holder is fixed on a centre in the manner
of a planing machine, so that by an adjusting set screw the diamond or
other cutting stone may be made to cut lightly in going in or out, and
deeper in the return cut, when the machine is set to cut both ways in
the same crack.
In order to work the machine motion is given by means of a
cord or band to the pulley, causing the crank or eccentric to revolve.
The diamond or other cutting stone is set down to the required depth
of cut and cuts in and out of the same crack, the stud on the boss

page_text: of the cruuk giving one notch motion to the ratchet wheel and screw,
thus making the machine revolve the distance of one "crack," or by an
additional stud or crank boss the machine may be made so as to enable
it to cut two "cracks" on each revolution of the crank or eccentric.
Any suitable motive power may be employed.
DESCRIPTION OF THE DRAWINGS AND OF THE MANNER OF PERFORMING
OR PUTTING IN PRACTICE THE SAID INVENTION.
Fig. 1, elevation; Fig. 2, plan; Fig. 3, view of the mandrill (B) with
worm wheel therein; Fig. 4, view of lower end of spindle; Fig. 5, view
of tool holder; Fig. 6, plan of apparatus showing an arrangemont for
cutting double curves.
A denotes a hollow bridging box or carriage for the machine fitted
with set screws a, u, n, a. A mandrill B, Fig. 3, having a toothed or
cog wheel b cast on, and a round or other shaped nut and collar fitted to
top end. This mandrill is preferred cast hollow (sec dotted lines) for
lightness and to allow the stone spindle to stand up inside same when
dressing the bed stone. A main arm C, bored, turned, and fitted to
rovolve on the upper part of the mandrill B, resting at the same time on
the upper surface of the cog wheel b, the nut and collar D, D, being
screwed down sufficiently to give steadiness. A carriage E either cast or
bolted on to the main arm C, and fitted with set screws c, d, e, e, for
adjusting the socket N. N, in which the tool arm spindle revolves (or
turns with a reciprocating motion). The tool arm F keyed or tightly
fixed to a spindle turned and fitted into socket N, N, the crank being
also keyed or otherwise fixed to top end of same spindle. The tool
holder G, fixed by screws to end of tool arm. The tool II, bored and
fitted to rise or fall in same, and adjusted by the screw h, h, which is
tapped onto upper end of tool; for great nicety when at work screw h, h,
is worked by a worm wheel and scrow ✗. The bottom end of tool being
formed into a round or square box has four set screws for securely hold-
ing the diamond previously set in copper or other suitable metal, as
described below. A ratchet wheel or worm screw K, K, is fitted to
revolve in carriages bolted on back end of main arm, the worm screw
being fitted to work in the toothed wheel b. A click and spindle L, with
autifriction roll at the top end, is also fitted on main arm for communi-
cating motion to the ratchet wheel K. A spindle I, of any required
length, and having a gut pulley or other kind of wheel for receiving
motion fixed to the upper end or at any convenient part, gives a

page_text: rovolving motion to the eccentric J, and by the connecting rod i gives a
reciprocating motion to the crank J. The eccentric J has a cam You the
under side for giving motion to the click L. The diamond huldor we make
of copper in two pieces and of suitable length for the box in bottom end
of tool.
The mode of setting is as follows:-A recess being made in corre-
sponding parts of each half the diamond is placed between them, and
the screw P, Fig. 5, being put in and set tight the holder is then placed
in the tool, and the set screws tightened sufficiently to keep it firm and
steady.
The mode of using the machine is as follows:-The bridging box A
being firmly bolted on the stone by the bolts o, o, passing through the
eye (if the rnnner) or through holes drilled through the neck box (if the
bed stone) to the plate O. The mandrill B is set in the bridging box A,
the main arm C is placed on the same and screwed down sufficiently by
nut and collar D, D, to keep it steady. The main arm is now adjusted
to travel true with the face of the stone by the set screws a, a, a, a, in
bridging box, the screw M at the back end of main arm being intended
for use for this purpose in the process called tracing. The tool arm is
now by a similar process also brought to travel true over the face of the
stone, the studs r, r, on tool. holder being also afterwards adjusted so as
just to touch lightly up against the friction quadrant S, S, to keep the
diamond from rising up when in work. The spindle and cccentric I, J,
being now set on the machine, and the top end entered in a bearing pre-
viously fixed for it over the stone, on motion being given by gut from a
driving shaft the eccentric gives a reciprocating motion to the tool
arm F, the diamond passing in from the skirt of the stone towards the
centre and out again cuts one crank in a curved line, boing a segment of
a circle. The diamond being now off the stone and the eccentric at full
throw, the cam on the under side of eccentric give motion to the click and
ratchet wheel, and moves the main arm forward one crack, the distance of
the cracks apart being determined by the number of teeth in the ratchet
wheel. The machine, if kept going about an hour, will complete dressing
the stone all over.
We also make à modification of the machine, see Fig. 6, having two
tool arms, one nearer to the centre of the stone than the other, and
which may be placed, as shown, both on one end of main arm, or one on
the one end and the other the opposite. This machine is worked in a

page_text: similar way and is adapted for putting either a greater or less number of
cracks in the breast or near the eye of the stone than at the skirt.
These machines can also by a pair of bevil wheels or other convenient
plan be worked by hand if preferred. The machine may also be made to
make two cracks to each revolution of the driving spindle by having two
cams instead of one on the eccentric.
Having now described the nature of the said Invention, and in what
manner the same is to be performed or put in practice, we hereby declare
that we claim, the "Improvements in Dressing Millstones and in Appa-
ratus to be usod therefor " herein-beforo described and illustrated by
the Drawings, an important feature whereof is the adoption of a recipro-
cating motion operating for dressing stones with diamond or other hard
substance in the manner horein-before stated, it being understood that
we do not claim the mere details of construction herein-before described
and illustrated by the Drawings except when combined -and used as
herein-before stated.
In witness whereof, we, the said William Huggins and Henry
Horsnaill, have hereunto set our hands and seals, this Nineteenth
.. day of July, in the year of our Lord One thousand eight hundrod
and sixty-nine.
5
Witnesses to the signature of
William Huggins,
H. E. COTMAN,
Halstead.
W. H., BECKETT,
Of Chelmsford.
Witnesses to the signature of
0 Henry Horsnaill,
5
WILLIAM PANNELL,
Bullford' Mill,
Cressing.
WILLIAN JOHN HUGGINS,
Halstead.
WILLIAM HUGGINS. (L.B.)
'HENRY HORSNAILL. (L.s.)