Improvements in Apparatus for Grinding or Triturating Middlings and other like Materials.
Year: 1899

page_text: Date of Application, 2nd June, 1899
Complete Specification Left, 27th Feb., 1900-Accepted, 31st. Mar., 1900
Improvements in Apparatus for Grinding or Triturating Middlings
and other like Materials.
SIDNEY LEETHAM, of Elm Bank, in the City and County of York, Corn Miller,
do hereby declare the nature of this invention to be as follows:-
This invention relates to that type of apparatus for grinding or triturating
comparatively soft materials such as middlings, in which the material is fed along
a tubular chamber by an archimedian screw or spiral conveyer against a yielding
plate or end piece, between which and the end of the chamber, the material
escapes. In such machines, as at present constructed and employed, the action
of gravity prevents the distribution and discharge of the material uniformly
ground around the whole of the outlet from the chamber, from which it follows.
that the available efficiency of the apparatus cannot be realised.
According to my present invention, I so construct, arrange. and employ the
yielding end piece that the material is distributed and discharged uniformly
ground at the end of the chamber, thereby obtaining a higher efficiency for the
apparatus.
In the case of an apparatus of the existing construction I may so arrange the
end piece that the outlet from the chamber is wider at the top than at the bottom.
This may be accomplished in various ways, as for example, by inclining the end
piece so that at the upper part it is a little further from the end of the chamber
than at the lower part; by arranging the centre of the end piece a little below
the produced axis of the chamber; by cutting away the upper part of the end
piece, and the like.
When the apparatus is arranged vertically instead of horizontally as at present,
I may however use a circular end piece concentric with the chamber.
In any case, I may also construct upon the inner face of the yielding end
piece, a conical or conoidal projection, coaxial with the screw or conveyer, or
thereabouts.
The end piece, instead of yielding by resisted swinging, is arranged to yield in
the direction of the produced axis of the apparatus. It may be normally forced
in the direction of the screw or conveyer by a weight or spring.
Dated this 1st day of June A.D. 1899.
W. E. HEYS & SON,
Agents for the Applicant.
Improvements in Apparatus for Grinding or Triturating Middlings
and other like Materials.
I. SIDNEY LEETHAM, of Elm Bank, in the City and County of York, Corn
Miller, do hereby declare the nature of this invention, and in what manner the
[Price 8d.]

page_text: same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to that type of apparatus for grinding or titurating com-
paratively soft materials such as middlings cocoa spices certain ores dry clay
and the like, in which the material is fed along a tubular chamber by an archi-
medean screw or spiral conveyer against a yielding plate or end piece, between
which and the end of the chamber, the ground material escapes.
In such machines as at present constructed and employed, the action of gravity
prevents the distribution and discharge of the material uniformly ground around
the whole outlet of the chamber, from which it follows that the whole available
efficiency of the apparatus cannot be realised.
According to my present invention, I so construct arrange and employ the
yielding end piece that the material is distributed and discharged uniformly
ground at the end of the chamber, thereby obtaining a higher efficiency for the
apparatus.
In the case of an apparatus of the existing type of construction, I may so
arrange the end piece that the outlet from the chamber is wider at the top than
at the bottom. This may be accomplished in various ways, as for example, by
inclining the end piece so that at the upper part it is a little further from the
end of the chamber than at the lower part; by arranging the centre of the end
piece a little below the produced axis of the chamber; by cutting away the upper
part of the end piece or of the end of the chamber, and the like.
It will be clear that when the apparatus is arranged vertically instead of hori
zontally as at present, and when the upper end of the chamber is cut away, and
when the end piece is rotated, I may use a circular yielding end piece concentric
with the chamber.
In any case, I may also construct upon the inner face of the vielding end
piece, a conical or conoidal projection, coaxial with the screw or conveyer, or
thereabouts.
The end piece, instead of yielding by resisted swinging, is arranged to yield in
the direction of the produced axis of the apparatus. It may normally be forced
in the direction of the screw or conveyer by a weight or spring.
I will further describe my said invention with reference to the accompanying
drawings, in which: —
Figure 1 represents a longitudinal section; Figures 2 and 3, partial longi-
tudinal sections shewing modifications in connection with the yielding end piece
and outlet; Figure 4, a longitudinal section shewing a modification of the outlet
end of the grinding screw or conveyer; Figure 5, a partial section illustrating
the application of a weighted lever to the yielding end piece; and Figure 6. a
diagram shewing a crescent shaped outlet.
In the construction represented by Figure 1, A, indicates the grinding
chamber; B, the inlet for the unground material; D, the working shaft driven
by the pulley E, and carried by suitable bearings; G, the screw fixed upon the
shaft D; F, an extension of the shaft D; and P, the yielding end piece. This
violding end piece has an extended hub p, fitting upon F, but not rotating
therewith, rotation being prevented by a fixed stop or screw H, which engages
in a slot, formed in the extended hub p. The upper part of the end piece is
cut away as shewn, so that, as illustrated by the diagram Figure 6, a narrow
crescent-shaped opening is produced through which the ground or triturated
material can escape with an amount of resistance which is gradually reduced from
the bottom of the chamber to the top. By this construction, which can be vari-
ously modified, full allowance is made for the action of gravity. which normally
causes the material to escape principally at and near to the bottom where the
pressure is greatest. The pressure at the outlet being thus made uniform, the
material is uniformly ground or triturated, and more. uniformly escapes from the
outlet to the discharge opening 0.

page_text: This
Exactly the same result is obtained by the modification illustrated by Figure 2.
Here, instead of the upper part of the plate P being cut away, the upper part of
the end of the chamber is cut away or inclined as shewn at Z. In this case, the
end piece is circular and may be rotated by means of the fast key I, fitting in a
key-way or slot in the eye of the hub p. With a rotary end piece it may often
be advantageous to rotate it in a contrary direction to that of the screw.
may be effected by known means as illustrated by Figure 3. A spur wheel 1,
is fixed upon F and gears with the wheel 2, fixed on a shaft 3, parallel with F.
On the shaft 3 there is also fixed a spur wheel 4, gearing with the idle wheel 5,
which in turn gears with the wheel 6, fixed upon the hollow shaft or sleeve 7.
concentric with F. The extended hub of the end piece fits upon and is rotated
by the hollow shaft 7, by means similar to those already described with reference
to Figure 2.
The yielding end, piece is made more or less conoidal on its inner face accord-
ing to the nature of the material to be operated on, the conoidal face being
generally flatter for softer materials than for harder. The form shewn is about
that which I have found to be best for middlings.
It may be kept up to its work by a spring or springs or by gravity. As illus-
trated by Figures 1, 2, 3 and 4, a spring is employed. A spiral spring $, sur-
rounding the shaft F, abuts at one end against the extended hub p, through the
agency of a loose cupped collar as shewn, or not, and at the other end, against.
or in the hollow shaft of the hand wheel J. This hollow hand wheel shaft is
externally screw threaded and fits in a correspondingly threaded fixed nut,
which may conveniently form part of the bearing K; it may also be provided
with the hand locking nut L. The pressure to be exerted by the spring upon
the yielding end plate can be adjusted when desired by rotating the hand wheel J,
the locking nut being first released and afterwards retightened.
In the modification illustrated by Figure 5, the driving shaft D, does not
extend beyond the screw G, and the yielding end piece P, is fixed upon a non-
rotary shaft M. The vertical member N, of a cranked lever is pressed against the
end of the shaft M, by the weight W, suspended from the horizontal arm N¹ of
the cranked lever. Instead of cutting away the upper part of the end piece
with this modified construction, that is to say when the end piece is carried
upon a separate shaft, the end piece may be circular and its shaft be arranged
slightly lower than the shaft D, in which case the shaft M, instead of being
stationary, may be rotated by a separate pulley or otherwise.
If the apparatus has to be arranged vertically, instead of horizontally as illus-
trated by the drawings, since gravity will then act equally over the whole of the
outlet, no provision is made for widening the outlet at any part and the end
piece may be rotated as described with reference to either Figure 2 or Figure 3.
The screw G may have a single blade as shewn by Figure 1, or more than a
single blade as shewn by way of example by Figure 4. In either case, the outlet
end of the screw blade or blades may be extended so as to embrace the conoidal
part of the end piece P', as shewn by Figure 4.
I am aware of a prior arrangement in which a yielding end piece was used in
combination with a screw, the end piece being hinged about one edge thereof and
yielded by turning about the hinge. According to my invention, the end piece
vields by linear longitudinal displacement, and the opening all round the peri-
phery is longitudinally increased by the same amount all round. I regard this
as an important feature of my invention.
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. A machine for grinding or triturating comparatively soft materials, having
a cylindrical chamber and an archimedean screw working therein and having

page_text: a longitudinally displaceable end piece at the outlet acted upon by a spring or
weight, arranged and operating substantially as herein before described.
2. In a machine of the type set forth, the arrangement of a part moving longi-
tudinally under pressure of the material produced by the reaction of an archi-
medean screw so as to release the ground material, in combination with a spring
or weight applied so as to resist the movement of the part, substantially as
described.
3. In a machine of the type set forth, a longitudinally displaceable end piece
subjected to the centrally applied pressure of a spring or weight, arranged and
operating substantially as hereinbefore described.
4. In a machine of the type set forth, the combination and arrangement in con-
nection with the cylindrical chamber, of a longitudinally yielding conoidal end
piece having the conoidal form on its inner surface and around which the outlet
is constituted, with a screw or conveyer coaxial therewith, substantially as here-
in before described with reference to Figure 4, of the accompanying drawings.
5. In a machine of the type set forth, a longitudinally displaceable end piece
at the outlet having a conoidal form on its inner surface and acted upon by a
spring or weight, substantially as herein before described.
6. In a machine of the type set forth, the arrangement of the cylindrical
chamber with the longitudinally displaceable end piece so as to form an outlet
wider at the upper than at the lower part, substantially as and for the purpose
described.
7. The various modifications of the improved machine or apparatus for grinding
or triturating comparatively soft materials, constructed and arranged substantially
as hereinbefore described with reference to the several drawings.
Dated this 96th day of February
1000
W. E. HEYS & SON,
Agents for the Applicant..