Iμ- PROVEMENTS IN MACHINERY FOR PULVERIZING AND LEVIGATING BY MEANS OF PESTLE AND MORTAR
Year: 1855

page_text: Sealed the 8th February 1856, and dated the 11th August 1855.
PROVISIONAL SPECIFICATION left by the said Thomas Hewitt at the
Office of the Commissioners of Patents, with his Petition, on the 11th
August 1855.
I, THOMAS HEWITT, of Lorn Street, Chester Road, in the City of Manchester,
Pattern Maker, do hereby declare the nature of the said Invention for :* Iμ-
PROVEMENTS IN MACHINERY FOR PULVERIZING AND LEVIGATING BY MEANS OF PESTLE
AND MORTAR" to be as follows:-
My Invention consists in improved modes of working a pestle in a mortar.
The handle of the pestle is supported in a swivel bearing, and the upper end of
the handle fits in a slot in a pulley, or is connected to a sliding bush.fitting
in the said pulley, to which rotary motion is given in any convenient manner;
by this means a rotary motion is given to the pestle within the mortar, but an
excentric motion may occasionally be given to the pestle, if required, by means
of a cam acting on the sliding bush in the pulley, or by other means. These
combined rotary and excentric motions of the pestle produce the desired effect
for pulverizing or levigating the substances contained in the mortar.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Hewitt in the Great Seal Patent Office on the
9th February 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HEWITT, of Lorn Street, Chester Road, in the City of Manchester, Pattern
Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of August, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Hewitt, Her special license that I, the said Thomas Hewitt, my
executors, administrators, and assigns, or such others as I, the said Thomas
Hewitt, 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, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MACHINERY FOR
PULVERIZING AND LEVIGATING BY MEANS OF PESTLE AND MORTAB," upon the con-
dition (amongst others) that I, the said Thomas Hewitt, my executors or
administrators, by an instrument in writing under my, 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 Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Hewitt, 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 follow-
ing Specification thereof, reference being had to the accompanying Sheet of
Drawings (that is to say):
The nature of my said Invention of improvements in machinery for pul-
verizing and levigating consists in certain improved combinations of parts for
imparting an excentric or concentric rotary and rolling motion to the pestles
of mortars; and in order that my Invention may be fully understood and
readily carried into effect, I will proceed to describe the means pursued
by me.
Figure 1 is an elevation, and Figure 2 a plan, in section, through the line
A, B, of Figure 1, of my improved machinery for pulverizing and levigating.
a is a mortar, and b a pestle, of the ordinary construction; c is a standard,

page_text: secured to the same table or other article as the mortar a. The standard c
has a projecting arm d, to which the stud e is bolted; this stud supports
the groove pulley f, shewn in section in Figure 1, which is turned round by
the band g passing over the guide pulleys h, h, and under the driving pulley i,
which is attached to or cast with the fly wheel j, revolving on the stud k,
fixed to the standard c. To the upper side of the groove pulley f is fixed a
bracket 1, through which passes the stud m, for the worm wheel n gearing into
a worm o, formed on the lower end of the stud e. A crank pin p projects from
the face of the worn wheel n, for giving a traverse motion to the slide which
moves to and fro in a slot in the groove pulley f; the crank pin p passes
through one end of the link q', the other end of which is jointed to a projection
from the slide 9, and by increasing or diminishing the distance of the crank
pin from the centre of the worm wheel, more or less traverse may be given
to the slide.
The end of the pestle is secured into a socket at the lower end of the pestle
rod r, the upper end of which fits in a hole in the slide 7; the pestle rod passes
at or near the centre of its length through the ball sockets, which fits in a
bearing made in the projection d' of the standard c; the weights fit on the
pestle rod r, and serve to increase the action of the pestle 6 on the material to
be ground or levigated in the mortar a. When motion is given to the fly
wheel j, which may be communicated by hand or other power, the band g
causes the groove pulley f to revolve; the pestle is thus made to rotate in the
mortar, but the diameters of the rotations of the pestle are constantly varying,
owing to the traversing motion of the slide q, the worm wheel g being moved
partly round at every revolution of the pulley f by the action of the teeth of
the worm wheel against the stationary worm 0. The friction of the pestle
against the material in the mortar causes the pestle to roll or revolve around
its own axis, thereby producing the rotary, excentric, and rolling motions
required for effectually and expeditiously grinding or levigating the material in
the mortar. In order to increase the rolling action of the pestle b, a band t,
passing around the pulley u¹ fixed to the pestle rod r, and around the groove
pulley attached to the pulley i, may be used. By varying the relative
diameters of the pulleys and u', the rotary motion of the pestle may be
increased or diminished with facility. The pestle rod, being loose in the bear-
ings and slide q, is at liberty to rise or fall, according to the shape of the
mortar or the inequalities of the material within it, the weights, being
increased or diminished to suit the material; and when the materials are suffi-
ciently ground or levigated, the attendant by raising the pestle rod can remove
the mortar for the purpose of emptying its contents.

page_text: In Figures 3 and 4 I have shewn another modification of my Invention. In
this instance the traverse motion of the slide q is imparted by means of the
spur pinion t, which is formed on the stud e; this pinion, when the pulley f
revolves, causes the wheel u to rotate on its axis, which axis passes through a
projecting boss on the pulley f; to the lower extremity of the axis of the
wheel is fixed the excentric u, which fits between the projecting shoulders
on the under side of the slide 9. The amount of traverse may be increased or
diminished by varying the distance of the centre of the excentric from the
centre of the axis. In other respects this machine is similar to that above
described in reference to Figures 1 and 2. In some cases the machinery for
giving the traverse. motion to the slide 9 may be dispensed with, and the
end of the pestle rod is then made to pass through a hole in the disc plate
of the pulley f.
Having thus stated the nature of my Invention, and described the manner
of performing the same, I wish it to be understood that I do not limit myself
to the details herein set forth, as the same may be varied without departing
from the peculiar character of my Invention; but what I do claim is, the
improved combinations of machinery for imparting an excentric or concentric
rotary and rolling motion to the pestles of mortars, as shewn and described.
In witness whereof, I, the said Thomas Hewitt, have hereunto set my
hand and seal, this Seventh day of February, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
H. B. BARLOW,
Manchester.
THOMAS HEWITT. (L.S.)