IMPROVEMENTS IN APPARATUS FOR WITHERING AND DRYING TEA LEAF and TREATING OTHER SUBSTANCES
Year: 1884

page_text: I, JOHN DICK of Glasgow in the County of Lanark, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
WITHERING AND DRYING TEA LEAF and TREATING OTHER SUBSTANCES' to be as
follows:-
"
This Invention relates to improvements in apparatus for withering and drying
the green leaf of the tea plant in the manufacture of tea and which apparatus is
also applicable to be used in drying hops, grain, and other substances and it is a
further development of or alternative arrangement for part of the apparatus
constituting the subject matter of the invention under the application for Letters
Patent made by James Andrew Ramsey Main and myself the 26th day of May 1884.
Number 8195.
The present Invention has for its object to expose the leaf or other substance
being treated in a thin shower to the action of the air current instead of blowing
air through the substance in bulk as under the said prior application.
The apparatus constituting the Invention consists essentially of two hollow
longitudinal shelves preferably curved in cross-section and open at their inner ends.
The said shelves, the upper surfaces of which are perforated or formed partly of
sheet metal and partly of wire cloth are contained in a casing open at the top for
egress of the moist air after use and at each end they are fitted with a lever arm
working on a trunnion or centre. The outer end of each arm is attached by means
of a pin and slot to a connecting rod whose other end is secured on a pin fixed
eccentrically in the side of a toothed wheel engaging with spur gearing on a
longitudinal shaft constituting the main or driving shaft of the machine.
By this arrangement the shelves are raised through an arc alternately and
they are thus brought into position to slowly discharge or pour the substance
under treatment on to the other shelf during which discharge the air, which
ascends from inlets at the bottom or sides of the casing, or is conveyed to the
interior of the shelves by means of a hollow trunnion, acts upon the said substance
to dry or wither it.
The shelf after discharging the substance rapidly descends and remains at rest
whilst the other shelf ascends and discharges the contents back to the first and so
on alternately and constantly by which arrangement the ventilating and consequent
TD.31

page_text: .
drying of the substance is efficiently performed by the intimate nction of the air
current upon it whilst the operation of the machine is free from liability to injure
the leaf or substance by concussion or abrasion.
The substance to be treated is delivered intermittently from a hopper at one end
of the machine on to one end of one or both shelves by an endless band or its
equivalent actuated from the main shaft and the shelves are so arranged as in their
operation to gradually deliver the substance into a hopper formed at the outer end
of one shelf.
Instead of having two shelves as described the apparatus may have a series
of shelves arranged to discharge the substance from a higher to a lower one
in the series until the discharging hopper at the bottom of the machine is
reached and at its inner end each shelf may have a lip or edge which when the
shelf is discharging is or may be folded down by coming in contact with a rod or
otherwise.

page_text: COMPLETE SPECIFICATION.
I, JOHN DICK of Glasgow in the County of Lanark, Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR WITHERING
AND DRYING TEA LEAF AND TREATING OTHER SUBSTANCES;" and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
This invention relates to improvements in apparatus for withering and drying
the green leaf of the tea plant in the manufacture of tea the said apparatus being
also applicable to be used in drying hops grain and other substances and it
has for its object to expose the leaf or other substance being treated in a
thin shower or otherwise to the action of an air current the material when
sufficiently treated being delivered from the apparatus through a hopper or
shoot.
On the sheet of drawings hereunto appended figure 1, is a longitudinal vertical
section, figure 2 a part end elevation and part transverse section and figure 3 a plan
of the apparatus constituting the Invention and which consists of two hollow
shelves A, X, extending longitudinally between two end frames B, the space in which
the shelves are situated being boxed in or enclosed by a sheet metal, wood or other
casing C, The shelves A, X, are preferably dished or concave in transverse section
and they are open at their inner ends the upper surface being solid, or perforated:
in which latter case it is formed of wire cloth or sheet metal or partly of wire
cloth and partly of sheet metal. At both extremities each shelf is furnished with
a lever arm D, centred or fulcrumed at E, other levers D', being also ful. rumed on
the same centre and each connected to one end of a link F, whose other end is
attached to a pin G, fixed eccentrically in a spur wheel H, keyed on a shaft I,
extending underneath the casing C, from end to end of the apparatus. The
shafts I, are preferably geared at both ends and the wheels H, on one shaft I, gear
with corresponding wheels J, keyed on a shaft K, whilst the wheels H, on the
other shaft I, gear with similar wheels L, also fixed on the shaft K, which receives
notion through the bevel wheel M, and pinion N, the latter being fixed on a
shaft O, furnished with fast and loose pulleys P, or other equivalent means of
operating the moving parts of the apparatus.
Excepting the wheels M, N, the toothed gearing employed is preferably elliptical
as indicated and arranged to give a slow upward travel to the shelves A, X whilst
the travel in the reverse direction is accelerated.
The levers D, extend from the centres E, to the outer parts of the hollow.
shelves A, X, and the levers at ono side of the machine are or may be solid or of
the usual construction whilst those at the other side constitute pipes or tubes which
after passing between the upper and lower part of the shelf to the outer edge
thereof are bent and pass longitudinally to the other ends of the apparatus as seen
at D. These hollow levers work through trunnions E, each formed with a
branch b, for the inlet of air which passes up the hollow lever to the part Du
parallel with the length of the apparatus the said part being made with holes.

page_text: through which the air is discharged a portion of the volume passing out through
the perforated upper surface of the shelf and a portion through its open inner end
or when perforations are not made in the upper surface then the whole volume
discharges through the open inner end of the shelf.
Instead of the lever D, at one end of each shelf being solid both levers may be
hollow for the admission of air, or both levers may be solid in which case the air
is admitted through inlets in the bottom or sides of the casing C. The green tea
leaf or other substance to be treated is filled into the hopper Q, which is furnished
with a bottom or discharge part R, centred on a spindle c. The said discharge part
has an open portion d, and a closed portion e, and it is worked from a lever D, by a
link, and crank g, so as to intermittently bring its open and closed parts opposite
the lower part of the hopper and so feed or cut off the supply of material to the
upper shelf A, or instead of the link f, and crank g, the feed may be worked
by an endless band passed round pulleys on the shafts K, and c, or by equivalent
means.
As scen at figure 1, the shelves A, and other parts of the apparatus incline down-
wards in the direction of their length that is from the feeding to the discharge ond
the amount of inclination being regulated by screws S, the lower parts of which
are connected to the end frame B, whilst their upper parts work through brackets T,
by which the said frame is supported. At the other end of the apparatus the
frame B, is carried on studs or trunnions h, to enable the adjustment of inclination
to be effected.
By the arrangement of levers herein before described the shelves A, are raised
alternately through an arc around the centres E, that is to say, one shelf is in
the upper whilst the other is in the lower position shown by figure 2.
The shelf A, when in its lower position receives the substance to be treated from
the hopper Q, and in the act of being raised it slowly discharges the material in a
thin stream on to the shelf X, during which discharge the substance is ventilated
and dried by the air issuing through the perforations in the upper surface-and
through the open end of the shelf A, or through its open end merely the saturated
nir escaping through the opening V, in the top of the casing C. After so discharging
its material the shelf A, is by the elliptical gearing caused rapidly to descend
whilst the shelf X, slowly ascends and gradually pours the substance back to the
shelf A, the ventilating or drying action being continued by the air issuing from
or through the shelf X
An operation very analogous to pouring materials from one hand to the
other and in the act blowing through the falling stream with the breath is thus
performed.
The pouring from shelf to shelf is continued until on account of the downward
inclination in the length of the shelves the substance is finally discharged from the
upper shelf A, into the hopper U, by which it is conducted out of the apparatus a
quantity of material equal to that discharged being fed in at the other end of the
shelf from the hopper Q.
By the intimate action of the air currents upon it the drying of the substance is
efficiently performed whilst the operation of the machine affords an important
freedom from liability to injure the leaf or substance by concussion or abrasion.
Instead of having only two shelves as shown on the drawings the apparatus
may have a series of shelves arranged to discharge the substance from a higher
to a lower one until the discharge hopper at the bottom of the machine is
reached.
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
First The general arrangement and combination of parts constituting the
improved apparatus for withering and drying tea leaf and treating other sub-
stances substantially as hereinbefore described and in part shown on the drawings
annexed.

page_text: Second-In apparatus for withering and drying tea leaf and other substances the
arrangement of shelves, operating so as to pour the material from one to the other
and successively back again or not substantially as described and in part shown on
the appended drawings, the material during such discharge being blown through by
air currents as set forth.
Third In apparatus for withering and drying ten leaf and other substances
the use of shelves acting so as to pour the material from one to the other and
back again in successive operations the material the while being blown through by
air currents.