Improvements in Grinding or Pulverising Sugar, Salt, and other like Material, and in Apparatus or Machinery therefor.
Year: 1887

page_text: Date of Application, 25th Oct., 1887
Complete Specification Left, 25th July, 1888
Complete Specification Accepted, 31st Aug., 1888
Improvements in Grinding or Pulverising Sugar, Salt, and other
like Material, and in Apparatus or Machinery therefor.
I, ANTHONY STEVENSON of 10, Grosvenor Park Road, Chestor in the County.of
Chester, Millwright and Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object a method of grinding or pulverising salt, sugar and
other granular or other like brittle material so as to make a powder of even granulation
or fineness throughout without the necessity of sifting.
To effect this object 1 use a roll preferably of phosphor bronze as being at
once hard, tough and not much affected by salt and therefore not liable to discolor
the latter.
This roll has a series of sharp-edged grooves, preferably about twenty to the inch
when fine salt is required, cut on its surface from one side to the other with a slight
spiral advance.
Above the roll is placed a hopper into which the salt or sugar is thrown. The roll
revolving, each of its sharp edges cuts off a small string or filament of granules from
the mass, and the mass itself being exceedingly brittle this string or filament, in
forming, breaks up into granules and falls from the roll into a hopper or other
receptacle below.
In case of slightly sticky material a stationary, reciprocating or revolving brush
can be placed below to detach the granules from the roller; but in the case of
salt and most varieties of sugar when free from moisture, this is not required.
The object of giving the grooves a slight spiral direction on the face of the roller is
to enable them to cut better and with less shocks, as no edge can strike a piece
of sugar or salt parallel with the side of the hopper throughout its length at once.
Dated this 24th October 1887.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
. Agents for the Applicant.

page_text: Improvements in Grinding or Pulverising Sugar, Salt, and other
like Material, and in Apparatus or Machinery therefor.
I, ANTHONY STEVENSON, of 10 Grosvenor Park Road, Chester, in the County of
Chester, Millwright and Engineer, 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:-
This invention has for its object a method of grinding or pulverising salt, sugar,
or other granular or brittle material, so as to make a powder of an even granulation
or fineness throughout, without the necessity of sifting.
For grinding or pulverising materials in accordance with my invention, variously
constructed machines may be employed. One convenient form of machine is shown
in the accompanying drawings, in which,
Figure 1 is an end elevation of the machine.
Figure 2 a longitudinal section of the same, and
Figure 3 an enlarged transverse section of a portion of the grinding roll.
The essential portion of the machine is a roll, such as A, which is preferably of
phosphor bronze, this metal being hard, tough, and not much affected by salt, and
therefore not liable to discolor the latter. The rollers may, however, be made of chilled
iron or any suitable material.
The roll A has a series of sharp-edged grooves a the pitch of which varies according
to circumstances, but it is preferably about twenty to the inch, when fine salt is
required. The grooves are cut on its surface from one end, to the other, with a
slight spiral advance. The exact contour of the grooves may be varied, but the saw
tooth form shown in Figure 3 answers very well.
Above, or in front of, the roll is placed a hopper B or its equivalent, into or upon
which the lumps of salt or sugar are fed. As the roll revolves, each of its sharp
edges a cuts off a small string or filament of granules from the mass, and the mass
itself being exceedingly brittle, this string or filament, in forming, breaks up into
granules and falls from the roll into a hopper or other receptacle below. The roll
is supported upon a suitable framing D, and is driven by a pulley E or other con-
venient mechanism.
In the case of slightly sticky material, a stationary, reciprocating or revolving brush
can be placed below the roller to detach the granules therefrom; but in the case of salt
and most varieties of sugar when free from moisture, this is not required.
The object of giving the grooves a slight spiral direction on the face of the roller
is to enable them to cut better and with less shock, as no cutting edge can strike a
piece of sugar or salt at the same time throughout its length, and in a plane parallel to
the axis of the roller.
The roller. A may be placed vertically or obliquely in the hopper, if desired, instead
of horizontally as shown.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The method, substantially as described, of grinding or pulverising salt, sugar,
or the like, by cutting from a mass of the material under operation, a succession of
small strings or filaments of granules by means of a rotating roller having sharp
edged grooves on its periphery, whereby all necessity for subsequent sieving is
avoided.
2nd. A machine for grinding or pulverising salt, sugar, or the liko, consisting of
a revolving roller provided on its periphery with a series of sharp edged grooves such
as a, extending from end to end thereof, and having a slight spiral advance, and of a
hopper or its equivalent for feeding the material against the said roller, substantially
as described.
3rd. The grinding or pulverising machine, constructed as a whole, substantially as
shown and described.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicant.