IMPROVEMENTS IN MACHINERY OR APPARATUS FOR DRESSING SLATES."
Year: 1861

page_text: LETTERS PATENT to John Whitehead Greaves, of Port Madoc, in the
County of Carnarvon, Esquire, for the Invention of "IMPROVEMENTS IN
MACHINERY OR APPARATUS FOR DRESSING SLATES."
PROVISIONAL SPECIFICATION left by the said John Whitehead, Greaves-
at the Office of the Commissioners of Patents, with his Petition,,onx
the 18th May 1861..
I, JOHN WHITEHEAD GREAVES, of Port Madoc, in the County of Carnarvon,.
Esquire, do hereby declare the nature of the said Invention for "IMPROVEMENTS.
IN MACHINERY OR APPARATUS FOR DRESSING SLATES," to be as follows:-
This Invention relates to an improved construction; arrangement; and
combination of machinery or apparatus for dressing slates, whereby-accomo-
dation is afforded for two workmen at the same machine, thus producing double
the amount of work hitherto accomplished in machines of this description..
According to this Invention the knives or cutters are mounted at a slight.
angle or inclination to the axial centre line of the main shaft of the machine-
upon a pair of holding discs or frames. The cutting edges of the two knives.
are in opposite directions, so that by imparting a circular reciprocating motion.
to the discs the knives will alternately act upon and dress the edges of the

page_text: slates which are presented to them upon stationary cutters or knives at each
side of the machine. The reciprocating motion of the disc and their knives
may be derived from a revolving crank or cranks driven by a pulley and band,
and acting upon a lever arm or arms fast on the main shaft, or by any other
convenient mechanical contrivance. The different sizes of the slates are
guaged by suitable guages on each side of the machine.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Whitehead Greaves in the Great Seal Patent Office on
the 16th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WHITEHEAD GREAVES, of Port Madoc, in the County of Carnarvon, Esquire,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her. heirs and successors, give and grant unto me,
the said John Whitehead Greaves, Her special license that I, the said John
Whitehead Greaves, my executors, administrators, and assigns, or such others
as I, the said John Whitehead Greaves, my executors, administrators, or
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 MACHINERY OR APPARATUS FOR DRESSING SLATES," upon the
condition (amongst others) that I,, the said John Whitehead Greaves, my
executors or administrators, by an instrument in writing under my hand:
and seal, or under the hand and seal of one of them, 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 within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Whitehead Greaves, do hereby
declare 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, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:

page_text: My said, Invention relates to an improved construction, arrangement, and
combination of machinery or apparatus for dressing slates, whereby accomó-
dation is afforded for two workmen at the same machine, thus producing double
the amount of work hitherto accomplished in machines of this description.
According to this Invention the cutter or cutters is or are mounted at a slight
angle or inclination to the axial centre line of the main shaft of the machine
upon a pair of holding discs or frames. The cutting edges of the cutter or
cutters are in opposite directions, so that by imparting a circular reciprocating
motion to the discs they will alternately act upon and dress the edges, of the
slates, which are presented to them upon stationary cutters or knives at each
side of the machine. The reciprocating motion of the discs and their cutter
or cutters may be derived from a revolving crank or cranks driven by a pulley
and band, and acting upon a lever arm or arms fast on the main shaft, or by
any other convenient mechanical contrivance. The different sizes of the slates
are guaged by suitable guages on each side of the machine.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose I
shall refer to the Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts in both Figures.
Figure 1 of the Drawings represents a side elevation of my improved
double-action slate dressing machine; and Figure 2 is a corresponding plan
of the same.
A is the main framing of the machine; and B, B', are two knives or cutters
mounted on the discs C, C, fast on the shaft D, the knives being at an angle
with the shaft in place of being parallel therewith. A reciprocating motion is
imparted to the knives B by a crank or cranks at E on the crank shaft F, to
which a rotatory motion is imparted by a strap and driving pulley G, or by
any other suitable contrivance. H is a connecting rod serving to connect the
rotating crank E with the longer and reciprocating crank I, fast on the cutter
shaft: The rotation of the crank E imparts the desired oscillating or circular
reciprocating motion to the cutters, which have their cutting edges in opposite
directions, and act alternately upon slates laid on the two stationary cutters
K, K. L is a fly wheel fast on the driving shaft F, and M, M', are the
guages for determining the proper dimensions of the slates. It is obvious that
in lieu of two reciprocating cutters one such cutter only might be employed,
each edge acting alternately as a cutting edge.
.Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that what I consider to be novel and

page_text: original, and therefore claim as the Invention secured to me by the herein-
. before in part recited Letters Patent, is,-
First, the general combination of machinery or apparatus for dressing slates,
, as herein-before described and illustrated by my Drawings.
:
Second, the application and use in slate-dressing machines of a reciprocating
. cutter or cutters in combination with stationary knives or cutters, so arranged
as to enable slates to be dressed on opposite sides of the machine simulta-
neously, as herein-before described.
In witness whereof, I, the said John Whitehead. Greaves, have hereunto.
set my hand and seal, this Eleventh day of November, One thousand
eight hundred and sixty-one.
JOHN WHITEHEAD GREAVES. (L.S.)