IMPROVEMENTS IN MACHINERY FOR GRINDING AND POLISHING LITHOGRAPHIC AND OTHER STONES
Year: 1875

page_text: LETTERS PATENT to James Salmon, of Manchester, in the County of
Lancaster, Printers' Engineer, and William Crosland, of the same
Place, Machine Maker, for the Invention of "IMPROVEMENTS IN
MACHINERY FOR GRINDING AND POLISHING LITHOGRAPHIC AND OTHER
STONES."
PROVISIONAL SPECIFICATION left by the said James Salmon and
William Crosland at the Office of the Commissioners of Patents,
with their Petition, on the 17th February 1875.
We, JAMES SALMON, of Manchester, in the County of Lancaster,
Printers' Engineer, and WILLIAM CROSLAND, of the same Place, Machine
Maker, do hereby declare the nature of the said Invention for “Improve-
MENTS IN MACHINERY FOR GRINDING AND POLISHING LITHOGRAPHIC AND OTHER
STONES," to be as follows:-
-;

page_text: rapidly on a vertical spindle, and of a frame with movable jaws, by
which the stone to be ground and polished is moved; this frame is
supported on levers to which a vibrating motion is given by a crank on
the second motion shaft or otherwise.
When the machine is at work the stone rests upon the disc, and sand t
and water or other equivalents are supplied to the disc to grind the
whole surface of the stone at once. After the grinding is complete the
surface is polished by continuing the operation without sand. A circular
trough is placed round the disc to collect the sand and water.
In some cases a lateral to-and-fro motion is given to the stone by 1
means of a crank in lieu of the oscillating motion above described.
The above machinery is particularly applicable for effacing the marks
on lithographic stones, and to prepare the surface for being used over
again, but it may be used for grinding and polishing marble and other
stone.
1
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Salmon and William Crosland in the Great
Seal Patent Office on the 14th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
SALMON, of Manchester, in the County of Lancaster, Printers' Engineer,
and WILLIAM CROSLAND, of the same Place, Machine Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of February, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said James Salmon and William Crosland,
Her special licence that we, the said James Salmon and William Crosland,
our executors, administrators, and assigns, or such others as we, the
said James Salmon and William Crosland, 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,

page_text: Sheet of Drawings, reference being had to the figures and letters marked
thereon.
Fig. 1 is an elevation; Fig. 2, a plan; and Fig. 3, an end view of
our improved machinery for grinding and polishing..
a is the grinding disc, made by preference of cast iron which is keyed
on the vertical spindle 6 revolving rapidly in a footstep below and
above in a bearing, both the footstep and bearing are made in cross
frames by which the two main frames c are connected. Above the
grinding disc a is a frame consisting of the cross bars d and e supporting
the movable jaws d' and e', all of which can be set according to the size
of the stone to be ground and polished, or according to the position in
which it is held on the ginding disc, one end of the cross bar d is
supported on a roller in the stay c¹, and the other end is hinged to the
lever f fixed on the upright shaft f¹, to which is also fixed the slotted
lever. To the vertical spindle is keyed the spur pinion 6' which
gears into the wheel g mounted on a stud fixed in the lower cross frame,
and in the wheel g is a crank pin g' which in revolving communicates a
vibrating motion to the slotted lever f³ and cross bars d and e by means
of the connecting link j. The requisite rotary motion is given to the
disc a by the pulley ½ on the driving shaft h', on which is keyed the
bevel pinion h² gearing into the wheel 63 on the vertical spindle b. The
disc may however be driven in any other convenient manner, and the
lateral to-and-fro or oscillating motion may be given to the stone by
other means.
When the machine is at work sand and water are supplied to the
surface of the disc a to act on the surface of the stone resting upon the
disc, and when this grinding operation has been continued for a sufficient
time to efface the marks on the stone, the supply of sand is stopped and
the polishing is produced by the action of the pulverised sand remaining
on the disc, and the water or other grinding or polishing materials may
be used.
The sand and water thrown off the disc are collected in the annular
trough i fixed on the frames c.
Having thus stated the nature of our Invention and described a
convenient manner of performing the same, we declare that we claim

page_text: the improved machinery shewn and described for grinding and polishing
lithographic and other stones by the combined action of a revolving disc
and a movable frame for giving motion to the stone.
In witness whereof, we, the said James Salmon and William
Crosland, have hereto set our hands and seals, this Eleventh
day of August, One thousand eight hundred and seventy-five.
JAMES SALMON.
(L.S.)
WILLIAM CROSLAND. (L.S.)