Year: 1886

page_text: Date of Application, 3rd July, 1886.
Complete Left, 4th Apr., 1887.
Complete Accepted, 6th May, 1887.
I, JAMES MOSS BENNETT of Ruchill, in the County of Lanark, Metallurgist, do
hereby declare the nature of this invention to be as follows:-
In the manufacture of pigments from sulphate of lead or barytes or similar salts
and zinc oxide or other oxides which owing to their crystalline and translucent
character are deficient in "body" or covering powers as pigments or the bases of
paints the practise has heretofore obtained of crushing or grinding the substance in
pan mills or edge runners in order to reduce and pulverise the particles and thereby
impart to the pigments greater density and opacity. This method of treatment is not
uniformly successful and it cannot be carried out by grinding the substances in the
dry state owing to the liability to discolouration by overheating while the operation is
necessarily an intermittent one involving great attention and expenditure of time in
periodically removing the pulverised mass and replacing it by the raw or uncrushed
material.
The object of my invention is to overcome these difficulties in the manufacture of
pigments of the kinds referred to by the adoption of a process which consists in
breaking disintegrating, or compacting the particles in lieu of subjecting them
to frictional grinding and is continuous as regards the pulverisation and increasing of
the density of the materials while it results in the production of superior pigment at
less than the usual cost.
I employ for this purpose a disintegrator of any well known form, or a series of
disintegrators through which I lead in a continuous stream the sulphates, oxides or
other substances to be acted on. The disintegrating apparatus is preferably enclosed
to prevent the escape of noxious dust and to permit of directing currents of dried or
heated air through the material under treatment, dust collectors being also fitted in
connection with the apparatus when occasion requires. The velocity of rotation
of the disintegrators when there are several may be graduated so that a gradual
reduction of the particles may be brought about as they descend through the
apparatus. I also apply this my invention in the manner above described for the
treatment of carbonate of lead; lamp black and all other substances adapted for use as
pigments.
Dated this Second dave of T.1 1000
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Pigments.
I, JAMES Moss BENNETT of Ruchill in the County of Lanark Metallurgist, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
In the manufacture of pigments from materials which, owing to their crystalline
and translucent character, are deficient in body or covering powers as the basis of
paints, the practice has heretofore obtained of crushing or grinding the substance or
material in pan mills or edge runners burr mills or like apparatus in order to reduce
the particles to a pulverulent state and thereby to impart to the pigments greater
density and opacity. This method of treatment is not uniformly successful and when
burr or other grinding mills are used overheating and decolourization takes place in
grinding the materials or substances in a dry state whilst with pan mills the operation
has the objection of being necessarily an intermittent one involving great attention
and expenditure of time in periodically removing the pulverised mass and replacing it
by raw or uncrushed material.
•
The object of my invention is to overcome these difficulties by the adoption of a
process which consists in breaking, disintegrating or compacting the particles of the
substances being treated by a series of sudden impacts or shocks in lieu of subjecting
the materials to frictional grinding the said process and the apparatus employed in
carrying it out being continuous as regards their action and resulting in the
production of superior pigments or bases for paints at less than the usual cost.
Each
In carrying out the invention a disintegrator or series of disintegrators of any well
known kind may be employed but I prefer to use apparatus of the construction
illustrated in longitudinal section at figure 1 and in cross section at figure 2 of the
annexed drawings which apparatus I have found to be very suitable for the purpose.
The said apparatus consists of two discs a, a', each formed or mounted on a separate
spindle b, the spindles being carried in bearings c, and rotated in opposite directions
by belts or bands passed round pulleys d, or by gearing or equivalent means.
disc has a series of pins e, cast on or fixed in its inner side the pins being, as seen at
figure 2, arranged so that in rotating the discs a series or circle of pins on one disc
passes between two series or circles of pins on the other. The disc a is attached to its
spindle by a second disc f, which is connected to the disc by its inner series or circle
of pins e the said disc fentering a similarly shaped recess in the other disc a'. The
crystalline material to be treated is fed in from a hopper or shoot g, through the
disc a, into the space between it and the disc f and from thence it is by centrifugal
action thrown out between the discs a, a¹. In so passing out between the discs
the material is subjected to a series of sudden impacts or shocks from the pins e,
a¹,
whereby it is reduced or compacted to a finer and more opaque condition than when
acted upon by the class of apparatus herein before mentioned. From the compacting
or disintegrating discs the material, in a state of fine dust, is delivered into the
a,

page_text: chamber and is thence drawn off through the passage i into a dust chamber ; wherein
it is collected the action being obtained by exhaust fans one of which may be arranged
in communication with several dust chambers ; or each dust chamber may have a
separate exhauster or exhausters.
During the process of compacting or disintegrating, currents of heated or dried air
may be passed into or through the chamber h and where there are a series of
disintegrators in communication with each other the velocity of rotation of the several
pairs of discs may be graduated so that a gradual reduction of the particles may be
brought about as they descend or pass through the apparatus.
The invention may be applied in the manner above described to the treatment of
sulphate of lead or barytes, carbonate of lead or similar salts, zinc oxide or other
oxides, lamp black and all other substances adapted for use as pigments.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is :-
In the manufacture of pigments as bases of paints treating the materials or
substances in a dry state in one or a series of breakers, disintegrators or compacters
enclosed within a chamber or chambers through which currents of dried or heated air
are or may be passed, substantially as herein before described.
Dated this Second day of April 1887.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow,
Agents.