Improvements in Apparatus for Mixing Tea and other Granular Substances.
Year: 1895

page_text: Date of Application, 23rd May, 1895
Complete Specification Left, 24th Feb., 1896-Accepted, 9th May,
1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Mixing Tea and other Granular
Substances.
I, CHARLES HENRY BARTLETT, of 2, and 3, Welsh Back, Bristol, in the
County of Gloucester, Weighing Machine Manufacturer, do hereby declare the
nature of this invention to be as follows:-
My invention relates to apparatus particularly designed for mixing or blending
teas, but also applicable for mixing other granular substances, and has reference
more especially to that class of apparatus which is self delivering through an
axial aperture in the end of the mixing drum.
According to my present invention the discharge of the contents of the mixing
drum is effected through an inclined shoot which projects inwardly through the
front trunnion of the drum a distance sufficient to receive, and outwardly so far as
may be required to conveniently deliver, the tea, the shoot being carried by a
circular plate adapted to completely close the aperture of the trunnion, and
retained in place therein by means of a gland, or similar contrivance, but
prevented from turning with the drum.
It will thus be seen that whilst the mixing drum is rotating, the shoot remains
The inwardly
constantly in position for receiving and discharging the contents.
projecting or receiving part of the shoot is provided with a sliding door or hood
for preventing the delivery whilst the mixing is in progress and is covered by a
sieve for the purpose hereafter mentioned.
In order to deliver the tea to the inner or receiving end of the shoot, helical
blades are arranged within the drum so as, when the latter is rotated in the proper
direction, to bring the contents to the front end where they are received by con-
verging cups delivering the contents gently on to the screen above the inwardly
projecting end of the discharging shoot. So long, however, as the sluice door or
hood remains closed, no tea can escape, that which is deposited thereon falling
back on to one or more helical conveyors of reverse twist to the blades whereby
the contents are returned to the back end of the drum.
The object of the sieve before referred to is to prevent the separation of
differing grades of fineness during the discharge. It will be obvious that in a
flowing stream of tea or other granular material there is a tendency for the
smaller particles to sink to the bottom and lag behind the larger which run more
freely on the upper surface of the stream. In order to check this tendency,
which neutralizes to some extent the efficiency of the mixing apparatus, the
receiving end of the discharge shoot is covered by a sieve of which the mesh is so
proportioned to the grades of the tea or other material in the mixer as to retard
to the necessary extent the passage of the larger particles whilst affording a
comparatively free passage to the smaller, and thus to maintain the desired
proportions of the blend.
Both the screen aud the hood may be gable shaped, the hood being fitted, in
any case, to slide in and out through the shoot carrying plate to admit of the
discharge being controlled whilst the machine is running and the screen may be
similarly fitted to admit of being changed as required.
Dated this 22nd dow of May 1895
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.

page_text: Improvements in Apparatus for Mixing Tea and other Granular
Substances.
1, CHARLES HENRY BARTLETT of 2, and 3, Welsh Back, Bristol, in the
County of Gloucester, Weighing Machine Manufacturer, 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:-
My invention relates to apparatus particularly designed for mixing or blending
teas but also applicable for mixing other granular substances and the invention
has reference more especially to that class of apparatus which is self discharging
through an axial aperture in the end of the mixing drum.
My present invention consists in inmounting the discharge shoot permanently in
position within the front trunnion of the drum into which it projects a distance
sufficient to receive the tea from the mixing and discharging pallets, the shoot
projecting outwardly as far as may be required to deliver the tea, the shoot being
carried preferably by a circular plate fitting the aperture of the trunnion but
prevented from turning with the drum. The inwardly projecting or receiving
part of the shoot is provided with a sliding cover or hood for preventing the
delivery of tea to the shoot whilst the mixing is in progress. The drum is
provided with internal helical blades whereby the tea is brought to cups or con-
verging shoots at the front end which deliver the tea gently to the discharging
shoot. So long as the hood remains closed the tea deposited thereon falls back on
to one or more helical conveyors of reverse twist to that of the blades whereby the
tea is returned to the back end of the drum.
The invention is illustrated in the accompanying drawings forming part of this
Specification wherein
Figure 1 is a cross section and Figure 2 a perspective view looking towards the
front or discharge end of the drum.
Figure 3 is a front end elevation and Figure 4 a vertical section through the
discharge trough.
A is the drum supported by its end trunnions A¹ A' (the front one resting on
bearing rollers) and slowly rotated by any suitable means and B are the helical
mixing blades (say four, more or less, in number) fixed to the periphery of the
drum and extending from the back nearly to the front end thereof the pitch of the
helix being about equal to, say, four times the length of the drum so that each
blade B extends over about one-fourth the circumference of the drum. The
blades are not normal to the drum in the direction of their width but make there-
with an acute angle on their leading or advancing side as shewn, the inner edge
of the blade having a forwardly turned lip b as shewn. Each blade B terminates
at one side and at the outermost end of a shoot or cup C these cups C con-
verging more or less radially inwards and terminating at such a point that in
revolving with the drum their inner ends will pass clear around the inwardly
projecting part of the stationary discharge shoot D. This shoot is fixed
permanently in position in a disc E filling the aperture of the front trunnion A
and making a sufficiently tight joint therewith by means of a gland. This disc E
and shoot D are held stationary by an outside bracket F. The shoot D projects
within the drum for about half the length of the shoot or to a distance equal to
the width of the radial shoots or cups C so as to receive the tea therefrom when
this part of the shoot is uncovered. During the mixing operation it is covered by
the hood H which is preferably of gable shape so as not to allow of the tea
lodging thereon, this hood being fitted to slide upon the edges of the shoot D and
through the correspondingly shaped aperture in the plate E when it is drawn
forward to uncover the inwardly projecting part of the shoot. The cover might

page_text: be a flat plate but in that case some tea would lodge thereon which is a slight
disadvantage. This gable shaped hood is closed at the inner end to prevent
escape of dust by abutting against a correspondingly shaped lip d projecting up
from the end of the shoot. G is a helical blade within the drum of reverse twist
to the blades B and extending like the latter from a cup C to which it is attached
to the back end of the drum. Only one such reverse blade G is shewn, to avoid
confusion, but two would generally be used. They are not in contact with the
periphery of the drum (except at the rear end) but at some distance therefrom
and they serve the purpose during the mixing operation of circulating the tea
towards the back end of the drum so that it shall not accumulate at the front end
by being continually brought forward by the blades B and delivered by the cups C
on to the hood covering the shoot.
As in a flowing stream of tea there is a tendency for the finer particles to sink
to the bottom and lag behind the larger particles which run more freely on the
surface of the stream, the larger particles would tend to be discharged before the
smaller particles thus neutralizing to some extent the efficiency of the apparatus,
but I find that the reverse blade G being necessarily arranged as described so as
to pass within the circle described by the inner edge of the first blade B which it
crosses, tends to return towards the back end the uppermost particles of the mass
of tea lying in the drum thus preventing the aggregation of the larger particles
towards the front of the drum and their premature discharge when the shoot is
uncovered.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a machine for blending tea and other granular substances the combination,
with a revolving drum having helical mixing blades and radial cups or shoots as
described of a stationary inclined shoot mounted within the trunnion and projecting
into the drum so as to receive the contents from the radial shoots or cups and
deliver the same as described.
2. Mounting the stationary discharge shoot in a disc filling the aperture of the
trunnion and making a joint therewith as described.
3. Providing the inwardly projecting part of the discharge shoot mounted as
described with a cover or hood fitted to slide through the shoot carrying disc as
described.
4. In a mixing drum provided with peripheral mixing blades of helical form
tending to feed the contents towards the front end the combination therewith of one
or more helical blades of reverse twist passing through the drum within the circle
described by the mixing blades substantially as and for the purpose specified.
Dated this 22nd day of February 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.