Improvements in that Form of Sifting Machine known as Plansichters, and other Mechanism in which Granular or Pulverulent Material is Caused to Travel along Sieves, Channels, or Trays.
Year: 1896

page_text: Date of Application, 14th Jan., 1896
Complete Specification Left, 21st Aug., 1896-Accepted, .10th Oct., 1895
PROVISIONAL SPECIFICATION.
Improvements in that Form of Sifting Machine known as
Plansichters, and other Mechanism in which Granular or
Pulverulent Material is Caused to Travel along Sieves,
Channels, or Trays.
A communication by GOTTLIEB LUTHER, of Brunswick, in the Duchy of
Brunswick, in the Empire of Germany, Milling Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118 New Street, Birmingham, in the County of
Warwick, and 31, High Holborn, in the County of Middlesex, Civil Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention has for its object an improvement in that type of machines known
as plansichters in order to enable the material to travel continuously forward in the
channels. It is applicable however to all machines where granular or pulverulent
materials have to travel along channels which receive a rapid rotary motion like a
hand-sieve.
The invention consists essentially in means whereby the backward resultant of
the circular motion is neutralised or impeded while the forward resultant is as
much as possible given free play.
The invention can be carried out in several ways, namely as follows:-I form a
long skeleton plate of wire netting with metallic binding at the edges. This wire
netting or other rough material is placed at one side of the channel and is fastened
at each end of the sieve, and if necessary at intermediate points to stays so as to
hold it rigidly in position, one edge being a short distance above the sieve and the
other preferably at a greater distance, the entire plate being therefore oblique.
The material on the sieves by its rotary motion comes in contact with this wire-
work and the metallic bindings and thus is impeded in its backward motion but the
other side of the channel being plain snooth walls it is nut impeded in the forward
motion, which is on that side. In place of this wire-work plate I may form a
horizontal or nearly horizontal plate of wire-work tin plate, perforated metal or
other stout material supported loosely on projections from the sides or ends of the
sieve or lying on ledges. Out of this plate I cut at intervals three sides of a
rectangle or other shape and bend these down so that they shall project downwards
at right angles or at an oblique angle towards the sieve. They are also preferably
at right angles to the sieve walls but their lower edge is preferably sloping from
near the side of the channel upwards so that towards the centre of the channel and
still more towards the other side there is little or no obstruction. These bent
pieces at intervals form obstructions to the motion of the material on one side and
therefore act in the same manner as the oblique plate. The supports of the plate
can be adjustable so that it can be raised or lowered either on both sides or on one
side. The plate is also made loose so that as the sieve revolves it jerks backwards
and forwards and so shakes the sieve. In place of these partially cut out pieces
I may fix dependent pieces to a solid plate or may form these dependent pieces of
steel or other elastic or springy material and curved or placed oblique to the
direction of travel and extending the whole way across the sieve or sieve channel.
In this case the elastic plate allows the material to slide under it giving way to the

page_text: material but when the backward motion takes place the material comes against a
much more rigid surface or forces the plate against the sieve and thus stops the
passage of the material being sieved. In this case as in the last the forward
resultant of notion is comparatively unimpeded. It is only the backward which is
arrested. It is obvious that the wire-work or other rough oblique plate first
mentiqued could be fixed to a loose plate resting on the supports and can be used
instead of these springy plates. The cover plate is useful in preventing the dust
rising as well as forming a restricting weight to shake the sieve.
Dated the 13th day of January 1895.
WM. P: THOMPSON & Co.,
Of.6 Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in, that Form of. Sifting Machine known as
Plansichters, and other Mechanism in which Granular or
Pulverulent. Material is Caused to Travel along. Sieves,
Channels, or Trays.
A communication by GOTTLIEB LUTHER, of Brunswick,. in the Duchy of
Brunswick, in the Empire of Germany, Milling Engineer.
1, WILLIAM PHILLIPS THOMPSON,. F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham in the County, of
Warwick, and 322, formerly of 31, High Holborn in the County of Middlesex,
Civil 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 :-
This invention has for its object an improvement in that type of machines known
as plansifters in order to enable the material to travel continuously forward in the
channels. It is applicable however to all machines where granular or pulverulent
materials have to travel along channels which receive a rapid rotary motion like a
hand sieve.
The invention is best described by aid of the accompanying drawings, in
which
Fig. 1 is a longitudinal section,
Fig. 2 transverse section, and
Fig. 3 a plan of one mode of carrying the invention into effect.
Figs. 4 to 6 show a slight variation, and
Figs. 7 to 9 another slight variation.
In these A A is a plate suspended either horizontally or obliquely above the
sieve and somewhat less in horizontal dimensions than the sieve box or frame,
whereby this plate, when the sieve is shaken with a rotary motion, oscillates
slightly from side to side and from end to end of the sieve frame striking the sieve
frame and thus giving it four knocks in the course of one revolution, two at the
sides and two at the ends producing thus a dither which assists in shaking the
frame free. To prevent. this plate. cutting into the sides and ends of the sieve
frame it is bent round at each end and at each side so as to present a large surface
to the sieve frame. B B are blades either flat or curved projecting down from
plate A to near the surface of the sieve and offering a greater impediment to the
material travelling on one side of the sieve than to material travelling on the other
side, or else so sloped. either with a curve, as in Figs. 7 to 9, or straight but oblique
as to cause much more resistance to the material travelling in one direction than

page_text: travelling in the other, in which case these plates extend down to nearly the entire.
width of the frame, whereas when they are required to give greater resistance on
one side than on the other, the plate is cut away more on the side where the
resistance is not required than on the other side, or as in Fig. 1'the plate A or the
bottom of the plate itself gradually rises higher and higher from the sieve surface
as it approaches the side at which the material is required to be not impeded or less
impeded. C is the sieve frame, and D the sieve. Like figures relate to like parts
in all the drawings.
The mode of working is as follows:-The sieve being placed either horizontally
or inclined and being rotated by two equal cranks one at each end rotating
horizontally, or by a single crank in the centre with guiding devices or in other
ways, whereby a circular motion shall be given to every part of the sieve and sieve
frame, the material is passed on to the sieve at one end, say F (Fig. 1) and escapes.
over the tailings, say G (Fig. 1) at the other end, the lighter particles having fallen
through the sieve. The sieve rotating in the direction shown by the arrow opposite
Fig. 3 the material can freely travel in a circular path along the side H, but in its.
circular path it arrives near the side I, its upper portion at least comes in contact.
with the lower portion of the blades B and is thus impeded or shot straight across.
the sieve instead of following the circular course. The result is, the forward.
resultant of motion being impeded and the backward resultant being impeled, the
material slowly travels along the sieve. In Figs. 7 to 9 a somewhat different.
action ensues. Here the lower edges of plates B extend nearly across the sieve and
are preferably at equal distance throughout from the sieve. This sieve differs.
from that above too in that it can be driven with a reciprocating motion if desired
instead of a rotary motion and in fact this form of sieve is best driven with
reciprocating motion. The forward reciprocation sends the grain forward under
the plates B and that portion of the grain which strikes the blades is yet deflected
downwards and forwards consequently there is little impediment to the material
going forwards. In the case however of the backward reciprocation a large part.
of the material strikes the blade and is deflected upwards and when the forward
reciprocation takes place this grain is thrown forward by the blade, or if in the
meantime it has fallen down, the very slope of the blade causes it to fall forward.
In this way these blades deflect the material onward to the tailings G. Figs. 10.
to 12 show a third variation, also used with a rotary motion. In this case the
frame of wirework is placed obliquely on the side in which impeding is required
with its lower edge preferably a little above the sieve and the sieve is rotated in the
direction set forth by the arrow opposite Fig. 12, the material consequently passing
in the direction set forth in the arrow on Fig. 12. This wirework plate is also
préferably made somewhat shorter in length than the interior of the sieve frame
and laid loose on its supports so that it also shall act as an anchor to knock the
sieve. In place of wirework it is obvious that perforated metal, roughened metal
or even smooth metal or plate or bored could be used instead of the wirework. It
is found however that wirework is much superior to any of these. In thus
describing the invention so far my correspondent has simply described it for sieves,.
but it is obvious that precisely the same arrangement can be used when the bottom
is imperforate in fact on channels or trays.
Having now particularly described and ascertained the nature of the said inver-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent I declare that what I claim is :-
1. The improvement in plansifters and other mechanism in which granular or
pulverulent material is caused to travel along a sieve channel or tray which consists
in suspending a series of blades impeding wire-work or other impediments arranged
above the sieve channel or tray in combination with rotary motion substantially as
described, whereby greater impediment is given to the backward resultant of
motion than to the forward one, and thus the material is caused to gradually travel
forward.

page_text: 2. In combination with a sieve tray or channel, a series of oblique blades or like
impediments suspended a little above the surface forming an oblique angle with the
forward line of travel of the material in combination with a reciprocating or
equivalent motion, whereby the material is little impeded in its forward movement
but is considerably impeded in its backward movement substantially as described.
3. In combination with impediments above the sieve substantially as described
in Claims 1 and 2, an arrangement whereby the said impediments are free to move
in a body independently of the sieve frame to a limited extent and to come against
the frame, whereby with the motion of the sieve the impediments are caused to
strike the sides and ends or either of them of the sieve, and thus assist by the dither
in keeping the sieve clear.
Dated the 20th day of August 1896.
WM. P. THOMPSON & Co.,
Agents.