Improvements in the Trays or Carriers of Apparatus for Exposing Tea, Coffee, Cocoa, Grain, and other Substances, to the Drying or other Action of Air, Vapor, or Gases.
Year: 1896

page_text: Date of Application, 3rd Feb., 1896-Accepted, 14th Mar., 1396
COMPLETE SPECIFICATION.
Improvements in the Trays or Carriers of Apparatus for Exposing
Tea, Coffee, Cocoa, Grain, and other Substances, to the Drying or
other Action of Air, Vapor, or Gases.
I, SAMUEL CLELAND DAVIDSON of Sirocco Engineering Works, Belfast,
Ireland, Merchant, 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 reference more particularly to the trays or carriers which are
pivotted between the endless chains or bands of the apparatus described in the
Specifications of previous Letters Patent dated (a) 2nd February 1892 No. 2046
and (6) dated 19th November 1894 No. 22341 (which Specifications for brevity of
description are hereinafter referred to as the previous Specifications) but they are
also applicable to any other apparatus in which pivotted or tilting trays are used
for similar purposes, on endless chains or bands, so that the said trays when
horizontally in line form a continuous perforated web upon which material is
carried for drying or other purposes.
The trays or carriers as described in the previous Specifications were constructed
preferably of a single sheet of perforated metal plate, stiffened from end to end
by means of iron rods or bars rivetted thereto longitudinally on one or both sides
of the plate, but the employment of these stiffening bars in this construction of
tray made it so heavy that it was inclined to sag in centre where unsupported, and
these stiffening bars also filled up the perforations of the trays, so far as the same
were covered thereby. The object of the hereinafter described invention is to so
construct these trays that the stiffening bars used in them will not block up any of
the perforations; and that the trays will be considerably stiffer from end to end
than formerly, and yet lighter in weight, while at the same time a portion of the
air, vapor or gas may pass through the tray comparatively freely, so as to reach the
material on the next succeeding stretch or web of trays without its initial
iemperature or condition being thereby to any considerable extent reduced or
altered.
According to the present invention the trays are constructed with two perforated
or foraminous metal plates or strips, in the centre of each of which lengthwise a
comparatively large corrugation of approximately semi-circular or V-shaped cross-
section is formed from end to end, with a smaller one on each side and the two
plates are then laid face to face with the concave sides of the corrugations opposite
to one another, so as to form tubular.cavities between them, extending the entire
length of the tray. One of the plates is preferably made slightly wider than the
other, so that when they are placed against one another, with their concave
corrugations immediately opposite, the excess in width of the wider plate can be
folded over upon the edge of the narrower one, and when these over-folds are
pressed down tightly, they securely hold the enclosed plate between them, the flat
meeting faces of the plates being further secured together by rivets. The tubular
cavities thus formed between the two plates give the trays great strength and
stiffness combined with lightness. In order to further add to their stiffness, I insert
into the large and central tubular cavity at right angles to the surfaces of the
tray, a longitudinal strip of metal plate of preferably about No. 10 or No. 12 B.W.G.
the full diameter of the cavity and a tight fit therein from end to end, so that it
presses against the top and bottom inuer faces of the cavity.

page_text: The trays when thus formed have next metal ends bolted or rivetted on to them,
of suitable form for pivotting to the conveyor chains between which the trays are
carried, with a projecting bar or pin thereon which fits tightly into the ends of the
large central tubular cavities of the trays, with a slot or groove cut into it at
right angles to the flat surface of the tray and into which slots each end of the
central metal stiffening slip is inserted, and thereby held securely in position.
When thus constructed the complete tray has similar convex corrugatious on both
.sides. When the material to be dried, is spread on these trays it necessarily lies
very thinly over the large central corrugation, so that the air passes through the
same more easily than through the deeper layers on the flat surfaces, and conse-
quently this corrugation in each tray practically acts as a by-pass for allowing a
portion of the air, vapor or gas to pass through to the material on the next
succeeding stretch or web of trays, without its initial temperature or condition
being to any considerable extent reduced or altered, and it thereby reaches the
same in a comparatively fresh state, and so equally distributed that it acts very
evenly all over it from end to end.
The comparative largeness of the central corrugation of each tray, relatively to
that on either side also assists in effecting a more even distribution of the material,
when discharged by the trays to the lower stretch or web, as described in the
previous Specification No. 22341 of 1894, as it longitudinally divides the material
on the tray so that in the working of the apparatus, when the tray makes its first
partial drop, only the portion of the material which is on the lower side of the
corrugation is discharged therefrom to the under stretch of trays after which on
the tray being further drawn forward in its course, and making its second drop to
a completely vertical position, the remaining portion of the material on the upper
side of the corrugation is discharged. A better distribution of the material upon
the under stretch of the web, than was the case with the trays when constructed
as described in the previous Specification No. 22341 of 1894 is thus ensured.
Reference to the accompanying drawings will more fully explain the nature of
the invention and how it is carried into effect: In these drawings:--
Figure 1 is a plan of the improved tray or carrier, constructed to hinge or
swing on a pivot about one-third of its width from one of its edges and in which
V-shaped corrugations are formed on each strip or plate whereby when the two
plates are put together to form the complete tray approximately rectangular
tubular cavities are formed between them.
Figure 2 is a cross-section of Figure 1 showing the V-shaped corrugations
forming the above mentioned approximately rectangular tubular cavities.
Figure 3 is a plan of the improved tray or carrier with semi-circular corruga-
tions on each strip or plate, whereby when the two plates are put together to
form the complete tray approximately circular tubular cavities are formed between
them.
Figure 4 is a cross-section of Figure 3 showing the semi-circular corrugations
forming the above mentioned approximately circular tubular cavities between
them.
Figure 5 is a plan of the improved tray or carrier similar to Figures 3 and 4
but constructed to hinge or swing on a pivot at or near the edge of the tray.
Figure 6 is a cross-section of Figure 5.
Figure 7 is a sectional elevation of a portion of the apparatus mentioned in the
previous Specification No. 22341 of 1894, to illustrate the adaptation of the
improved trays or carriers therein as hereinafter referred to.
The letters indicating the various parts are the same in all the figures and are as
follows:-
A and B are plates or strips of perforated metal or other foraminous material
(A being the wider plate) in each of which are formed approximately semi-circular
or V-shaped corrugations, the larger and central ones of which are marked C, and
the smaller and side ones D D. A narrow strip of metal E is (when the trays are
required to be extra stiff aud strong), inserted into the circular or rectangular

page_text: tube X formed by the two semi-circular or V-shaped corrugations in the centre of
the tray when the plates A and B are attached together face to face. FF are
metal ends which are secured firmly by bolts H H or other suitable fastenings on
each end of the tray formed when the plates A and B are rivetted together face to
face; these ends being so constructed that the tray as a whole may be pivotted
thereby in any suitable way to the conveyor chain G, either by having the pivots
projecting from the said chain into a sufficiently slack fitting recess in the tray
end F to let the tray swing freely thereon, as illustrated in the accompanying
drawings or by the pivot being on the tray end itself, and projecting into a suitable
recess or carrier in the conveyor chains. H'H' are bars or pins on the tray ends F
which project a short way into the large central tubular cavity C of the trays,
which pins H have slots H at right angles to the flat surfaces of the tray,
into which slots H the ends of the stiffening strip E are inserted, and are thereby
held firmly at right angles to the flat surfaces of the tray. K is a sprocket wheel as
used in the apparatus described in the previous Specification No. 22341 of 1894;
L and M are the stops against which (as also described in the said previous
Specification) the trays or carriers swing in the working of the apparatus.
It will readily be seen on looking at Figures 2 and 4 that when the wider
plate A is placed against the plate B, with the concave corrugations C and D D of
the one immediately opposite those of the other, and the excess in width of the
plate A is folded over upon the edge of the plate B, and pressed down tightly it
securely holds the plate B, and that the corrugations of the two plates then form
very strong and stiffening tubular cavities X and Y; which are then still further
strengthened by the insertion into the tubular cavity C of the stiffening metal
strip E, and that when the flat meeting faces of the plates are further secured
firmly together by rivets O, and the metal tray ends F F are bolted thereon, a
complete tray is thus formed with similar convex corrugations on both faces.
The more even distribution of the material by means of the comparative largeness
of the centre corrugation C will be more clearly understood on reference to
Figure 7, in which a carrier or tray P is shown as having just fallen to such an
angle against the stop L, that the material on the lower side only of the
corrugation C will fall off on to the tray or carrier Q immediately below, the
central corrugation preventing the other portion of the material on the tray P from
sliding off the tray until it has passed on to the point M when the tray finally
drops to a vertical position as shown and discharges the remainder of the material
to the stretch of trays below.
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 :-
1. The construction of pivotted or tilting trays, for apparatus in which tea,
coffee, cocoa, grain or other substance is exposed to the drying or other action of
air, vapor or gases, with two perforated or foraminous oblong metal plates or strips
having one or more longitudinal corrugations and secured together by rivetting or
otherwise with the concave faces of the corrugations opposite one another, so that
these form tubular cavities between the plates from end to end, and with end
attachments, to pivot them to or between chains or other form of conveyor bands
for carrying them through the chamber in which the material upon them is being
treated, all substantially as and for the purposes hereinbefore described and
represented in the accompanying drawings.
2. The construction of pivotted or tilting trays for apparatus in which tea,
coffee, cocoa, grain or other substance is exposed to the drying or other action of
air, vapor or gases with two perforated or foraminous oblong metal plates or strips
having one or more longitudinal corrugations and secured together by rivetting or
otherwise with the concave faces of the corrugations opposite one another, so that
these form tubular cavities between the plates from end to end with end attach-
ments to pivot them to or between chains or other form of conveyor bands, for

page_text: carrying them through the chamber in which the material upon them is being
treated and with a longitudinal strip of metal plate inserted in the largest of the
said tubular cavities at right angles to the flat surfaces of the tray, the said
longitudinal strip being the full diameter of the cavity so that it bears against the
top and bottom inner faces thereof, all substantially as and for the purposes herein-
before described and represented in the accompanying drawings.
3. The construction of pivotted or tilting trays for apparatus in which tea,
coffee, cocoa, grain or other substance is exposed to the drying or other action of
air, vapor, or gases with one or more sufficiently deep longitudinal convex corruga-
tions on the oblong perforated or foraminous metal plates or strips forming the
trays, so that very little if any of the material to be treated, when thrown or
spread on the trays, will lodge on the corrugations whereby the corrugations
operate as by-passes for a portion of the air, vapor or gases to flow through
comparatively freely, so that its temperature is not to any considerable extent
reduced or its condition altered, and it consequently reaches the material on the
next succeeding stretch of web in a comparatively fresh state, all substantially as
and for the purposes herein before described and represented in the accompanying
<lrawings.
4. The construction of pivotted or tilting trays for apparatus in which tea,
coffee, cocoa, grain or other substance is exposed to the drying or other action of
air, vapor or gases, with one or more sufficiently deep longitudinal convex corruga-
tions on the oblong perforated or foraminous metal plates or strips forming the
trays so that, very little if any of the material to be treated, when thrown or
spread on the trays will lodge on the corrugations whereby the corrugations
operate as obstruction bars which prevent the material on the upper side of the
same sliding off in the first drop of the tray, (as described in the previous
Specification No. 22341 of 1894) for the partial discharge of the material to the
web or stretch of trays below, all substantially as and for the purposes herein-
before described and represented in the accompanying drawings.
Dated this 3rd day of February 1896.
J. C. MEWBURN & ELLIS,
55 & 56 Chancery Lane, London, Chartered Patent Agents.