IMPROVEMENTS IN THE TREATMENT OF RICE AND APPARATUS THEREFOR."
Year: 1882

page_text: LETTERS PATENT to George Pawsey Witt of No 30, Mark Lane, in the City of
London, for an invention of "IMPROVEMENTS IN THE TREATMENT OF RICE
AND APPARATUS THEREFOR."
PROVISIONAL SPECIFICATION left by the said George Pawsey Witt at the
Office of the Commissioners of Patents on the 11th March 1882.
GEORGE PAWSEY WITT of No 30 Mark Lane in the City of London
MENTS IN THE TREATMENT OF RICE AND APPARATUS THEREFOR
"
"IMPROVE-
Rice is sometimes imported in the form of paddy with the hulls on all the grains,
but it is more commonly imported with the hulling partly effected, a large propor-
tion of the grains still remaining in the condition of paddy. My invention relates
to a method and apparatus for treating rice so as to facilitate the operation of
hulling and largely to diminish the amount of time and work which it involves,
also the breakage of the grains which usually occurs in shelling. For this purpose
when dealing with paddy, I first after cleansing the grain, size it by the use of
sieves or screens of successive degrees of fineness so as to collect in separate groups
(of which there may be three or four) grains of different sizes, each group consisting
of grains of approximately equal dimension I then hull each group separately in
the usual way, and thus produce with very little breakage rice to a large extent
hulled but with a proportion of the grains still retaining their hulls, and I deal with
the grain in this condition in the same way as I deal with the imperfectly hulled
rice above referred to after I have cleansed it. For this purpose I arrange in a
framing a number of screens or sieves of successive degrees of fineness, one above
the other, each placed somewhat inclined, and each having fixed under it a smooth
plate. To these screens with their plates I give quick and very short vibratory
movement by means of cranks, eccentrics or cams. I feed the grains to be operated
on at the higher end of the uppermost screen along which it is caused to travel by
the vibratory movement, the smaller grains dropping through the holes of the
screen and then travelling along the plate under it. At the farther end of the first

page_text: screen, the largest grains that had not passed through its holes are thrown off into
a receptacle, while those which had passed through and lodged on the plate are
delivered on to the upper end of the next screen in order, where a like selection of
grains is effected. And thus by the use of successive screens the grains having
their hulls on them being larger than like grains when bulled, become separated,
and can be subjected to hulling. Thus, instead of having to put through the
hulling process the whole bulk of rice because a proportion of it has escaped hulling,
I select from the bulk those grains which require hulling and operate only on
them, without having to deal with the others that are already bulled.
The arrangement of screens above described besides serving to separate the hulled
from the unhulled grains, can be used also for sizing the grains in the first instance,
or for sizing the rice when finished, screens of suitable perforations being employed.
Also while the grains are undergoing such screening they may be subjected to a
fan blast to carry off the lighter impurities.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Pawsey Witt in the Great Seal Patent Office on the 11th
September 1882.
GEORGE PAWSEY WITT of No 30 Mark Lane in the City of London
MENTS IN THE TREATMENT OF RICE AND APPARATUS THEREFOR
"
"
IMPROVE-
Rice is sometimes imported in the form of paddy with the hulls on all the grains,
but it is more commonly imported with the hulling partly effected, a large
proportion of the grains still remaining in the condition of paddy.
My invention relates to a method and apparatus for treating. rice so as to facili-
tate the operation of hulling and largely to diminish the amount of time and work
which it involves, also the breakage of the grains which usually occurs in shelling.
For this purpose, when dealing with paddy, I first after cleansing the grain, size it
by the use of sieves or screens of various degrees of fineness so as to collect in
separate groups (of which there may be three or four) grains of different sizes, each
group consisting of grains of approximately equal dimension. I then hull each
group separately in the usual way, and thus produce with very little breakage rice
to a large extent hulled but with a proportion of the grains still retaining their
hulls and I deal with the grain in this condition in the same way as I deal with
the imperfectly hulled rice above referred to, after I have cleansed it.
For this purpose I arrange in a framing a number of screens or sieves of various
degrees of fineness, one above the other, each placed somewhat inclined and each
having fixed under it a smooth plate. To these screens with their plates I give
quick and very short vibratory movement by means of cranks eccentrics or cams.
I feed the grains to be operated on at the higher end of the uppermost screen along
which it is caused to travel by the vibratory movement, the smaller grains dropping
through the holes of the screen and then travelling along the plate under it. At
the farther end of the first screen, the largest grains that had not passed through
its holes are thrown off into a receptacle, while those which had passed through
and lodged on the plate are delivered on to the upper end of the next screen in
order, where a like selection of grains is effected. And thus by the use of succes-
sive screens the grains having their hulls on them being larger than like grains
when hulled, become separated, and can be subjected to hulling. Thus instead of
having to put through the hulling process the whole bulk of rice because a portion
requires hulling I select from the bulk those grains which require hulling and
operate only on them without having to deal with the others that are already hulled.
The arrangement of screens above described besides serving to separate the
hulled from the unhulled grains, can be used also for sizing the grains in the first
instance, or for sizing the rice when finished, screens of suitable perforations being
employed. Also while the grains are undergoing such screening they may be
subjected to a fan blast to carry off the lighter impurities.
Fig. 1 of the accompanying drawings is a vertical section shewing how four
successive screens A¹ A* A³ A' may be arranged with their respective plates B' B*
B³ B to operate according to my invention. The rice partly bulled and partly
unhulled falls from the hopper C on to the upper part a' of the screen A¹ which
part is covered with a smooth plate so that the grains as they slide along it may
arrange themselves to lie on their sides before they reach the perforated part of the
screen. The small grains which are mostly those that are already hulled pass through
the screen to the plate B', and slide down it to its lower end where they are delivered
on to the covered part a* of the second screen A³. The larger grains that do not
pass through the screen A¹, being most unhulled are delivered by the shoot D' to

page_text: any convenient receptacle. With the other screens and their plates (of which there
may be four as shewn, or other number) the action is the same as described
with reference to the upper screen A¹ and its plate B¹.
Sometimes two screens
suffice for the desired separation of grains in which case the grains from the
plate B² may be prevented from falling on the screen A³ by a stopping plate and
may be delivered by a lateral shoot as indicated by the dotted lines at E³, the
grains from the screen A³ being either delivered outside by a shoot D² or delivered
on to the screen A³.
Obviously this arrangement can be applied at the end of the second as well as at
the end of the third screen according to the condition of the grains treated.
Fig. 2 shews a modified arrangement of the screens in which the part a³ is
perforated while the part a³ is a smooth plate. Below a³ is a smooth plate a' and
beyond this is a perforated screen as. In passing over the screen a² the hulled grains
and possibly a portion of the unhulled grains fall through on to the plate at while
the greater portion of the unhulled grains pass on to the smooth plate a³ and thence
on to the shoot D'. On passing from the plate a' on to the screen a³, the hulled
grains will fall through on to the plate B₁ while any unhulled grains that may be
.mixed therewith will pass along the screen and be delivered into a second shoot D*
or into the same shoot D¹ as the upper grains. The grains passing from the
plate B¹ may either pass on to another screen as at Fig. 1 or on to a shoot.
The inclined screens may receive vibratory motion from cranks cams or eccentrics
in any known manner. The speed of vibration and the extent of stroke may vary,
but practically I find that from 400 to 500 vibrations per minute, each vibration
not exceeding a quarter of an inch, answer very well. The screens are by prefer-
ence supported in an adjustable manner by any suitable known means so that their
inclination may be varied if found necessary.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim :-
Separating the hulled from the unhulled grains of rice by the action of a series of
rapidly vibrating inclined screens or sieves in combination with plates, arranged
and operating substantially as herein described
In witness whereof I the said George Pawsey Witt have hereunto set my
and seal this eighth day of September in the year of our Lord One
thousand eight hundred and eighty two.