IMPROVE- MENTS IN APPARATUS FOR DRESSING MILLSTONES
Year: 1868

page_text: LETTERS PATENT to John Norman, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR DRESSING MILLSTONES."
PROVISIONAL SPECIFICATION left by the said John Norman at
the Office of the Commissioners of Patents, with his Petition, on
the 16th March 1868.
I, JOHN NORMAN, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR DRESSING MILLSTONES," to be as follows,
that is to say:-
This Invention has for its object the construction and application
of simple, convenient, and inexpensive apparatus designed more par-
ticularly to facilitate the use of rapidly revolving diamonds in the
millstone dressing operation, but also applicable with other kinds of
dressing tools.

page_text: The improved apparatus comprises a horizontal guide rest, which is
truly planed on its under side to lie upon the stone, and has fitted
to it a slide carrying a short horizontal arm, which has on it a boss
with brackets carrying one or more revolving diamond carrying spindles.
The boss is moved on the arm between each stroke by a feed screw,
and the stroke is performed by hand by means of a handle on the slide
and by moving the slide along the main guide; or it may be made
to reciprocate by power in any convenient way. For guiding the
driving cord from a pulley on a central vertical spindle two pulleys
are carried by an adjustable arm on a rocking shaft held in a bracket
fixed to the main guide, and a spring is applied to an arm on the
rocking shaft to keep the cord in a state of tension. A small conical
friction clutch is applied to the driving pulley on the vertical spindle
for putting that pulley into or out of gear, instead of putting the
cord on or off as hitherto practised. To provide a footstep for the central
vertical driving spindle in the case of the running stone a disc is used
fitted with three radial screws, by which it can be fixed and centred in
the cyc of the stone; this disc is also formed with a boss to receive
washers of different sizes, up against which the guide rest is to be set,
and whereby its proper position can be determined. An adjustable
guide slip is provided, which can be set at any required angle on the
main guide for dressing the more central parts of the stone. The arm
carrying the tool boss may also be made adjustable, so that it can be
set at an angle for dressing the roads or portions of them, being in that
case hinged to the slide and fitted with an adjusting screw.
In another arrangement for. leading the driving cord to the tool
spindles the central vertical spindle is dispensed with, and the cord from
a horizontal shaft overhead is carried round a guide pulley near the
middle of the guide rest, thence horizontally to and round a guide pulley
at the outer, end of the rest, whence it returns, horizontally towards a
guide pulley at, the middle, which leads. it up to the. overhead shaft
again. In its horizontal course the cord is. carried round a guide
pulley on the slide, and then round the tool spindle or spindles,
returning round the guide pulley into its horizontal course again. As
the horizontal course of the cord is parallel to the motion of the slide
this motion does not vary the, tension of the cord.
fitted to, receive the slide at either. end, so as to serve either for stones
with right-handed roads or for those with left-handed ones; and a
The guide rest is

page_text: Patent, and of an Order of the Lord Chancellor, by the said
John Norman in the Great Scal Patent Office on the 18th September
1808..
TO ALL TO WHOM THESE PRESENTS SHALL COME; I, JOHN
NORMAN, of Glasgow, in the County of Lanark, North Britain,
Engineer,, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of March, in the year of
our Lord One thousand cight hundred and sixty-cight,, in the thirty-
first year of Her reign, did;. för Herself, Her hairs and successors,
give and grant unto me, the said John Norman, Her special licence
that I, the said John Norman, my executors, administrators, and
assigns, or such others as I, the said John Norman, my 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; tho
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
APPARATUS FOR DRESSING MILLSTONES," upon the condition (amongst others)
that I, the said John Norman, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, 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 Patent Office on or before
the Eighteenth day of September, One thousand eight hundred and
sixty-cight.
NOW KNOW YE, that I, the said John Norman, do hereby declaro
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement in writing, reference being had to the accom
panying Drawings, that is to say: -

page_text: My said Invention has for its object the construction and application
of simple, convenient, and inexpensive apparatus designed more par-
ticularly to facilitate the use of rapidly revolving diamonds in the
millstone dressing operation, but also applicable with other kinds of
dressing tools.
And in order that my said Invention, and the manner of performing
the same, may be properly understood I have hereunto appended a Sheet
of explanatory Drawings, to be herein-after referred to, and representing
a practically successful modification of my improved apparatus.
Figure 1 is a plan of the apparatus as applied upon a millstone ;
Figure 2 is a front elevation; and Figure 3 is an end clevation.
My improved apparatus comprises a horizontal guide rest 1, which
is truly planed on its under side to lie upon the surface of the mill-
stone 2, and has fitted to it upon v guides 3 on its vertical face a slide 4
carrying a short horizontal arm 5, which has on it a boss 6 with
'brackets 7 carrying one or more revolving diamond carrying spindles 8.
The arm 5 is hollow, and may be square, cylindrical, or of other
convenient form, the boss 6 being fitted upon it so as to move along it
between each stroke by the action of the feed screw 9 held in the
centre of the arm, and which acts on a nut connected to the boss G
through a slot formed along the under side of the arm. The screw 9 has
a toothed feed wheel on the front end of it, and this wheel is acted on
by a catch on a hand lever 10, the stroke of which is measured by means
of adjustable stop pins upon a sector disc 11. A small handle 12 is
adapted to the end of the feed screw 9 for turning it quickly when
required. The slide 4 with the arm 5 and parts thereon is moved back-
wards and forwards along the guide rest 1 by means of a handle 13 fixed
on it, and the revolving diamond is thereby made to cut on the lands of
the stone a series of fine grooves parallel to each other and at distances
apart depending on the feed motion, such being the kind of "dressing i
that it is the object of the apparatus to impart. If preferred the slide 4
may be moved along the guide rest 1 by means of a hand lever 14 on a
horizontal spindle carried by a standard 15 on the main guide 1, the
spindle having on its other end a lever 16 connected by a link 17 to
the slide 4. The slide 4 may also be made to reciprocate by power in
any convenient way. For guiding the driving cord 18 from a pulley 19
on a central vertical spindlo 20, two pulleys 21 are carried by an
adjustable arm 22 on a rocking shaft 23 carried by the standard or
دو

page_text: bracket 15, and a rubber or other spring 24 is applied to an arm 25 on
the rocking shaft to keep the cord in a state of tension, or a weight may
be applied to the arm 25 in the ordinary way. A small conical friction
clutch 26 is applied to the driving pulley 19 on the vertical spindle 20
for putting that pulley into or out of gear, instead of putting the cord
on or off as hitherto practised. The pulley 19 is carried loosely on a
collar on the spindle 20, and is formed with a conical boss on its upper
side down on which the clutch 26 fits. This clutch is geared to the
spindle by a key and groove, and when pushed up out of gear is kept up
by a friction spring. To provide a footstep for the central vertical
driving spindle 20 in the case of the running stone a disc 27 is used
fitted with three radial screws 28, by which it can be fixed and
centered in the cyc of the stone 2; this disc 27 is formed with a boss
projecting up centrally with the footstep bearing in it for the spindle,
and it may receive washers 29 of different sizes, up against which the
guide rest is to be set when made straight continuously across. It is
however found to be better to indent the middle part of the guide rest 1,
as shown in the Drawings, in order not to interfere with parts at the
eyes of some stones, and in that case an adjustable plate 30 is fixed to
the under side of the middle of the guide rest, and is brought up against
the washer 29 or against the boss itself. Washers of different sizes may
bc. provided or the plate 30 may be adjusted to set the guide rest nearer
to or further from the centre. The V guides 3 are formed by preference
on separate slips or plates, which are bolted to the main rest 1, each by
three bolts, and these plates can be slightly inclined from the horizontal
for dressing the more central parts of the stone. The end bolt holes
in the main rest are slightly clongated vertically to allow the plate to
turn a little on the middle bolt, and screws 31 are tapped through the
top of the rest, and are formed with collars to bear on the top edge of
and adjust the plate. The arm 5 carrying the tool boss 6 may also be
made adjustable, so that it can be set at an angle for dressing the roads
or portions of them, being in that case hinged to the slide and fitted
with an adjusting screw. It is, however, most convenient to provide an
extra V guide plate 3 shaped to hold the slide 4 and arm 5 at the
required angle.

page_text: the middle of the guide rest, thence horizontally to and round a guide
pulley at the outer end of the rest, whence it returns horizontally
towards a guide pulley at the middle, which leads it up to the over-
head shaft again. In its horizontal course the cord is carried round a
guide pulley on the slide, and then round the tool spindle or spindles,
returning round the guide pulley into its horizontal course again. As
the horizontal course of the cord is parallel to the motion of the slide,
this motion does not vary the tension of the cord. The guide rest is
fitted to receive the slide at either end, so as to serve either for
stones with right-handed roads or for those with left-handed ones.
Having thus particularly described my said Invention, and the
manner in which the same is to be performed, I have to state that
I do not restrict myself to the precise details herein described or
delineated; but that what I believe to be novel and original, and claim
as the Invention secured to me by the herein-before in part recited
Letters Patent is, the arranging and combining together of the parts
of apparatus for dressing millstones, substantially in the improved
manner hercin-before described.
In witness whereof, I, the said John Norman, have hereunto set
my hand and scal, this Twelfth day of September, in the year
of our Lord One thousand eight hundred and sixty-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JOHN NORMAN. (L.S.)