AN IMPROVED MACHINE FOR HULLING COFFEE AND RICE
Year: 1870

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," Southampton Buildings, London, Consulting
Engineer, for the Invention of "AN IMPROVED MACHINE FOR HULLING
COFFEE AND RICE."-A communication from abroad by Henry Thomas
Pratt and John Carver Alden, both of Bridgewater, Massachusetts,
United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, ou
the 28th June 1870.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
Southampton Buildings, London, Consulting Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED MACHINE FOR
HULLING COFFEE AND RICE," a communication, to be as follows:-
.
This Invention relates to machines for hulling coffee and rice in which
a rotary cylinder and stationary concave plate are employed. The
object of the said Invention is to obtain a machine for the purpose

page_text: specified which will not become choked or clogged while in operation, or
injure the article being operated upon (especially the coffee) by breaking
or grinding the hulls of the same.
The said Invention is more especially designed for hulling coffee for
which many machines have been devised, the most common consisting of
two metallic abrading surfaces between which the coffee is passed. In
some of these machines the abrading surfaces have been equidistant, a
space being left between them just sufficient to allow the decorticated
coffee beans to pass through without injury, but in most of them one or
both of the surfaces are made yielding by means of a spring or otherwise
in order to operate on beans of unequal size.
The devices for giving motion to the surfaces have been various;
discs have been used, one or both of which would revolve. Cylinders
revolving in a concave piece, which is concentric with its axis, have also
been employed. Planes having toothed or corrugated surfaces have also
been used for the purpose of hulling coffee, and arranged so as to have a
progressive or reciprocating motion, the coffee being held against the
planes or corrugated surfaces by springs pads or pressure plates, and
double planes have been used, one having a motion in one direction and
the other a cross motion or reverse to that of the first one, or both planes
being made with yielding surfaces.
It is evident that the cylinder machines have one advantage over all
others mentioned from the fact that the friction is nearly all thrown
upon the bearings of the cylinder, but these machines have hitherto
been less successful than the others, except under extremely complicated
conditions.
The object of this Invention is to improve the cylinder machine, and I
can best describe how this object is effected by alluding briefly to the
difficulties attending the operation of the ordinary cylinder machines.
A cylinder with a fixed or unyielding surface revolving in a concave
piece, which is also fixed and concentric, would of course only operate
on coffee beans of uniform dimensions. To avoid this difficulty the
concave piece has been made yielding in many ways, but all of which
are highly objectionable. The yielding concave piece has been made in
sections or parts; these sections or parts having each a separate yielding
movement one portion or section will recede and increase the distance
between it and the cylinder, either by the passage of a large bean or
berry, or bunch of beans, or a stone, and the tendency of the coffee is to

page_text: pack at that point, particularly if it is at the lower part of the cylinder,
so that the coffee by its own gravity may fall or roll into the cavity
thus created. The consequence of this packing is that the beans
or berries cease to roll for a moment, and being held stationary while
the cylinder is revolving are broken or abraded. Cylinders and cones
made of some yielding substance like india-rubber have also been used.
My machine consists of a cylinder rotating in fixed bearings and a
fixed concave plate or piece, the said concave plate being a half circle
or less, and made in one or more parts secured in a position concentric.
with the cylinder and at such a distance from it that a single bean of
unhulled coffee will be held in place without slipping between them.
It will therefore be seen that when the cylinder is revolved the bean
will also be revolved, and at the same time carried around with it, but
at a speed less than that of the cylinder. This rotary motion is of great
importance as it prevents the packing of the beans and no portion of
the surface of the bean is held in one place long enough to be injured.
It is of little consequence whether the body of the cylinder be
smooth or roughened; either surface will operate well. The cylinder is
made with openings extending the whole length of its milling surface.
There may be ten of them in a cylinder of fifteen inches in diameter,
that is to say, ten rows of openings. These openings are filled by
roughened pressure plates, which have the same curvature as the
cylinder, as will be hereafter more fully described. The effect is, to
subject the coffee to a constant rolling motion under pressure and not
to grind or cut it.
The hull soon yields to this treatment, and when sufficiently crushed
the bean will slip out of it. When hulled some of the beans are carried
along upon the solid portion of the cylinder and some continue to be
revolved, but are not injured. The number of rows of pressure plates
depends on the diameter of the cylinder, one inch space being allowed'
between the rows. The number of plates in cach row depends on the
length of the cylinder, the plates being placed as closely together in the
rows as practicable.
The hollow cylinder is fitted on a shaft, which is allowed to turn freely
in its bearings. The periphery of this cylinder is pierced or cast with
the series of holes in which the corrugated or toothed plates are fitted.
.
One plate is attached to a rod, which is allowed to slide freely in a
bearing. This rod has a spiral spring upon it, which has a tendency to

page_text: keep the plate thrust outward to its fullest extent. The other pressure
plate operates substantially in the same way, but the latter is pivotted
at one end and has a spiral spring bearing against its inner side.
The semicircular or concave piece or plate, extends about half
way round the cylinder, and is toothed or corrugated at its inner
side. This concave plate is concentric with the cylinder and may be
composed of sections bolted to side plates, one at each side of the
cylinder. A hopper conducts the unhulled coffee or other substance
down between the concave plate and cylinder.
It is designed to have a space of about one inch in length between
the ends of the pressure plates, and to have the latter but slightly
exceed in width the length of a coffee bean or berry. By this means
the beans are allowed to adjust themselves and turn freely between the
concave plate and pressure plates as the cylinder rotates. The object in
allowing spaces between the ends of the pressure plates is to permit
the dropping of the unhulled beans or berries between the ends of the
same.
The beans or berries are subjected to a rotation independent of the
rotation of the cylinder, so far as regards the carrying around of the
beans with the cylinder, and they thus have two motions, one with but
slower than the cylinder, and another (a rotary one) on their own axes.
It is designed, in practice, to have several longitudinal rows of pressure
plates across the cylinder, the number of rows corresponding of course
to its diameter, and the number of plates in each row corresponding to
its length.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Scal Patent
Office on the 3rd December 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," Southampton a
Buildings, London, Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of June, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-fourth

page_text: year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence
that I, the said William Robert Lake, my executors, administrators,
and assigns, or such others as I; the said William Robert Lake, 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 "AN IMPROVED
MACHINE FOR HULLING COFFEE AND RICE," (a communication to me from
abroad by Henry Thomas Pratt and John Carver Alden, both of Bridge-
water, Massachusetts, United States of America, upon the condition
(amongst others) that I, the said William Robert Lake, 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 William Robert Lake, do hereby
declare the nature of the 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
Drawing forming a part of this Specification:-
This Invention relates to machines (for hulling coffee, rice, and other
like substances,) in which a rotary cylinder and stationary concave plate
are employed. The object of the said Invention is to obtain a machine
for the purpose specified which will not become choked or clogged while
in operation or injure the article being operated upon (especially the
coffee) by breaking or grinding the hulls of the same.
The said Invention is more especially designed for hulling coffee, for
which purpose many machines have been devised, the most common
consisting of two metallic abrading surfaces, between which the coffee
is passed. In some of these machines the abrading surfaces have been
equidistant, a space being left between them just sufficient to allow
the decorticated coffee beans to pass through without injury, in most of
them one or both of the surfaces are made yielding by means of a spring
'or otherwise in order to operate on beans of unequal size.

page_text: The devices for giving motion to these surfaces have been various.
Discs have been used, one or both of which revolve, cylinders revolving
in a concave piece concentric with its axis have also been employed.
Planes having toothed or corrugated surfaces have also been used for
the purpose of hulling coffee, and arranged so as to have a progressive
or a reciprocating motion, the coffee being held against the planes or
corrugated surfaces by springs, pads, or pressure plates, double plancs
have also been used, one having a motion in one direction, and the
other a motion crosswise or reversely to that of the first, and one or both
planes being made with yielding surfaces.
It is evident that the cylinder machines have one advantage over
all others mentioned, from the fact that the friction is nearly all thrown
upon the bearings of the cylinder, but these machines have hitherto
been less successful than the others except under extremely compli-
cated conditions.
By this Invention I greatly improve the cylinder machine, and I
can best describe how this result is effected by alluding briefly to the
difficulties attending the operation of the ordinary cylinder machines.
A cylinder with a fixed or unyielding surface revolving in a concave
piece which is also fixed and concentric, would of course only operate
on coffee beans of uniform dimensions. To avoid this difficulty the
concave piece has been made yielding in many ways, all of which are
highly objectionable. The yielding concave piece has been made in
sections or parts; these sections or parts having each a separate yielding
movement, one portion or section will be caused to recede and increase
the distance between it and the cylinder, either by the passage of a
large bean or berry or bunch of beans or a stone, the tendency of
the coffee will then be to pack at that point, particularly if it is at the
lower part of the cylinder, so that the coffee by its own gravity may
fall or roll into the cavity thus created. The consequence of this
packing is that the beans or berries cease to roll for a moment, and
being held stationary while the cylinder is revolving are broken or
abraded. Cylinders and cones made of some yielding substance like
india-rubber have also been used.
My machine consists of a cylinder rotating in fixed bearings and a
fixed concave plate or piece, the said concave plate being a half circle
or less, and made in one or more parts secured in a position concentric
with the cylinder, and at such a distance from it that a single bean of

page_text: unhulled coffee will be held in place without slipping between them.
It will therefore be seen that when the cylinder is revolved the bean
will also be revolved, and at the same time carried around with it, but at
a speed less than that of the cylinder. This rotary motion is of great
importance as it prevents the packing of the beans, and no portion of
the surface of the bean is held in one place long enough to be injured.
It is of little consequence whether the body of the cylinder be
smooth or roughened, either surface will operate well. The cylinder
is made with openings extending the whole length of its milling
surface. There may be ten of them in a cylinder of fifteen inches in
diameter, that is to say, ten rows of openings.. These openings are
filled by roughened pressure plates which have the same curvature as
the cylinder, as will be herein-after more fully described. The effect is
to subject the coffee to a constant rolling motion under pressure without
grinding or cutting it.
The hull soon yields to this treatment and when sufficiently crushed
the bean will slip out of it. When hulled some of the beans are carried
along upon the solid portion of the cylinder and some continue to be
revolved but are not injured. The number of the rows of pressure plates
depends on the diameter of the cylinder, a space of one inch being
allowed between the rows. The number of plates in each row depends
on the length of the cylinder, the plates being placed as closely together
in the rows as practicable.

page_text: other pressure plate C¹ operates substantially in the same way, but is
pivoted at one end, as shewn at c', and has a spiral spring d bearing
against its inner side, as shewn clearly in both Figures.
however, the arrangement shown applied to plate C¹.
I prefer,
E is a semicircular or concave piece or plate which extends about
half way around the cylinder A, and is toothed or corrugated at its inner
side. This concave plate is concentric with the cylinder, and may be
composed of sections bolted to plates e, one at each side of the cylinder,
the said concave plate being fixed or stationary. F is an opening for a
hopper which conducts the unhulled coffee or other substance down
between the concave plate and cylinder.
It is designed in practice to have a space of about one inch in length
between the ends of the pressure plates, and to have the latter but
slightly exceed in width the length of a coffee bean or berry, say, about
half an inch. By this means the beans are allowed to adjust themselves
and turn freely between the concave plate and pressure plates as the
cylinder rotates. The object in allowing spaces between the ends of the
pressure plates is to permit the dropping of the unhulled beams or
berries between the ends of the same, a freedom of adjustment being
thereby allowed to the beans which greatly favours the stripping of the
hulls from the same. The springs c, d, give the requisite degree of
pressure to the plates C¹, to ensure the splitting of the hulls and the
detachment of the same from the beans without grinding or breaking
up the hulls, so that there will be no dust or powder to contend with
and also to prevent injury to the beans by abrasion.
This machine although it does not seem to differ at first sight or by a
superficial observation very materially from many other rotary machines
of the same class and for the same purpose effects very important
The beans or berries are sub-
results not attained by other machines.
jected to a rotation as the cylinder turns, and this rotation of the beans
is independant of the rotation of the cylinder so far as regards the
carrying around of the beans with the cylinder, the former having full
power to adjust themselves, and be deprived of their hulls without being
crushed or abraded, as would be the case were there any recesses in the
periphery of the cylinder for the beans to lodge and be carried around
in; they thus have two motions, one with the cylinder but slower
than the same, and another (a rotary motion) on their own axes.
two motions ensure the desired result previously alluded to, and such
These

page_text: result is favoured by having an unbroken concave surface, or one that has
no recesses in which the beans can collect or lodge, and be subjected to
unnecessary abrasion or be crushed.
It is designed in practice to have several longitudinal rows of pressure
plates across the cylinder, the number of rows depending of course upon
its diameter, and the number of plates in each row depending upon its
length.
Having thus fully described the said Invention as communicated
to me by my foreign correspondents, I wish it understood that I
claim,―
The hollow rotary cylinder A provided with the pressure plates C, C¹,
in combination with the fixed semicircular concave piece E, all arranged
substantially in the manner as and for the purpose set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Third day of December,
in the year of our Lord One thousand eight hundred and
Witness,
E. C. JACKSON.
WILLIAM ROBERT LAKE. (L.S.)