Improved Process and Apparatus for Shelling Liberian Coffee-fruit.
Year: 1896

page_text: Date of Application, 3rd Jan., 1896-Accepted, 21st Mar., 1896
COMPLETE SPECIFICATION.
Improved Process and Apparatus for Shelling Liberian Coffee-fruit.
I, THOMAS FREDERIK DOIJER of Pasoerean, Java, 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:
In preparing Liberian coffee the shelling of the fruit is of special importance
because the inner kernel is enclosed in a woody fibrous husk which is surrounded
by a red, tough fruit shell or peel containing tannin. But as far as I am aware no
satisfactory process or machinery has hitherto heen discovered for so freeing the
coffee kernel and its husk from the red fruit shell or peel that the coffee kernel
remains entirely free from the objectionable taste of tamin, because the substance
of the red fruit shell or peel adheres so firmly to the inner husk surrounding the
kernel that it has not been possible by the processes heretofore in use to separate
it completely from the kernel without imparting the taste of tannin to the latter.
The failure of the various attempts heretofore made to effect the complete
removal of the parts surrounding the firm kernel, without injuring the latter is
attributable in some degree to the varying nature or condition of the fruit to be
treated; for example during the early and late harvest it is not possible to gather
wholly ripe fruit, and unripe as well as diseased fruit is particularly difficult to
shell.
According to my invention I submit the fruit to a kneading process before
effecting the shelling of the coffee kernel in order to soften the substance of the
fruit shell or peel, and to loosen the same from the inner husk. The fruit with its
outer shell or peel thus softened and loosened from the inner husk is next subjected
to the action of a constant current of water, is thereby completely freed from the
said outer shell or peel and is then conducted to a suitable shelling machine con-
structed for that purpose.
The accompanying three sheets of drawings illustrate the machinery | employ
for carrying my invention into effect.
Figure 1 is a longitudinal section of the kneading apparatus.
Figure 2 is an end elevation of the same.
Figure 3 is a front elevation of the shelling machine.
Figure 4 is a half side elevation, and a half sectional elevation taken on the
line - of Figure 3.
Figure 5 is a plan of the shelling machine.
Figures 6 and 7 a side view and a plan respectively of the side cheeks to be con-
nected by screws or otherwise to the frame of the machine.
Figure 8 is a section through part of a preparatory bruising or squeezing roller.
Figures 9 to 11 inclusive are frout, side and top views of a funnel or hopper
to be placed in the side channels.
Figure 12 shows a general arrangement of the machinery as erected for work.
As seen in Figure there is mounted in the case a a suitably constructed
screw b by means of which the fruit is rubbed together and carried along to the
end of the case a where it falls through an outlet opening d, regulated by a slide e,
into a shoot e. This shoot has au culargement e 1 into which a stream of water is
delivered. The connection of the kneading apparatus with the shelling machine is
effected by means of a pipe p which leads to the bopper f of the shelling machine.
As shown in Figures 6 to 8 the hopper is in one piece with the side cheeks fl

page_text: and 2, and the flanges 3 serve to connect the cheeks with the frame of the
machine. On the hopper are two slides for regulating the inlet openings to the
dividing saddle h placed below the said hopper. These slides 9 can be clamped
in position by wing nuts as shown in Figure 4 or otherwise. The two sided
dividing saddle rests on two bars 3 connected by bolts 1 to the bar 2. These
bars 3 are pivoted lengthwise of the hopper in the two end walls/1 of the said
hopper, and are provided with slots to enable the distance of the dividing saddle
from the fluted rollers to be increased or diminished at pleasure. Below the
dividing saddle are arranged in suitable bearings two transporting and shelling
rollers having serew threads formed therein which start at a suitable angle right
and left from the middle of the length of the rollers as seen in Figures 3 and 5.
At a short distance from the fluted rollers j are arranged, in suitable bearings,
smooth rollers k, and these two pairs of rollers j k form the separator. To prevent
loss of fruit, wooden scrapers k1 are fitted to the rollers k; furthermore on the
inside of each of the two side cheeks 2 is placed a slide which can be so adjusted,
by means of wing nuts or otherwise that the opening m formed by the rollers j
and on the one hand, and the slide 7 on the other corresponds exactly to the size
of a tolerably smooth, shelled husk containing the inner kernel. The slides are
made and arranged so that they take the wear and tear due to the constant rubbing
of the hard husks, which wear and tear would otherwise be taken by the side
cheeks 2. The said slides are arranged so that they can be easily removed and
fresh ones put it. their places. As shown in Figures 3, 4 and 5 a funnel or hopper
(Figures 9 to 11) is placed behind each slide opening for receiving the shelled
husks; each of these funnels opens into a delivery pipe 1 delivering into a single
pipe n 2.
The substance forming the red fruit shell or peel falls between the two
rollers j and k, and is carried away by the washing water, whilst the parts adhering
to the rollers; and k are removed therefrom by the scrapers o.
The action of the machinery is as follows:
The fruit to be shelled is thrown into the kneading apparatus where it is seized
by the revolving screw and carried along thereby to the opening d. The fruit
shells or peels are rubbed one against the other, and against the screw b and the
red shell or peel surrounding the firm husk is loosened therefrom. The fruit thus
prepared or worked in the kneading machine is now ready for the shelling process.
The amount of rubbing to which the fruit has to be subjected in order to reach
the required condition varies according to the condition of the fruit, and this time
can be varied by suitably adjusting the size of the opening d by means of the
slide c.
The fruit thus prepared is now carried by the current of water through
the pipe p, shown in the general arrangement Figure 12, and the inlet of the
shelling machine on to the finely fluted dividing saddle h where it is torn up by
the latter and the preparatory bruising or squeezing rollers i, so that the substance
of the outer shell or peel remains hanging loosely to the firm husk of the kernel,
which with the said outer shell or peel falls on to the rollers the right and left
handed screw-like flutes of which force the said husk and substance of the shell
and peel outwards against the side cheeks 2. The smooth rollers & act along with
the rollers to form trays in which the material lies while being pushed along
towards the aforesaid side cheeks 2. As the slides arranged on the side
cheeks 2 are adjusted so that the openings they regulate correspond exactly to
the size of the shelled husk, only those husks that are completely freed from the
substance of the red shell or peel, and are polished clean, are allowed to pass
through such openings.
The machine may be driven by means of belt pulleys and tooth gearing in any
suitable way.
The advantages of this process and machinery are:-
1. That the kernel husk can be completely freed from the red fruit shell or peel.
2. That sifting and sorting apparatus is avoided, and
3. That the shelling process can be controlled and regulated without difficulty.

page_text: Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
First. The process for preparing Liberian coffee for the shelling process which
consists in subjecting the coffee fruit to a kneading process for the purpose of
loosening the fruit shell or peel from the kernel husk before the latter is submitted
to the shelling process substantially as described.
Second. For the purpose of carrying out the process herein described of
kneading the coffee fruit a kneading machine consisting of a screw b rotating in a
case a provided with an adjustable opening d at one end substantially as described
with reference to Figures 1 and 2 of the drawings.
Third. For the purpose of removing from the kernel husk the outer shell or
peel which has been previously softened by the kneading process herein described,
the shelling machine consisting of one or more pairs of fluted rollers j and smooth
rollers k, the flutes of the rollers being inclined at a suitable angle to the axis of
the roller and side cheeks 2 with openings therein which can be regulated by
slides to correspond to the exact size of the shelled husks, combined, arranged
and operating substantially as described with reference to Figures 3 to 11 of the
drawings.
Dated this 2nd day of Januar 1906
T. F. DOIJER,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.