An Improved Mode and Apparatus for Manufacturing by Pressure Flower Pots, Jars, and other Vessels from Semi-plastic Materials.
Year: 1890

page_text: Date of Application, 1st May, 1890
Complete Specification Left, 2nd Feb., 1891-Accepted. 14th Mar., 1891
PROVISIONAL SPECIFICATION.
An Improved Mode and Apparatus for Manufacturing by Pressure
Flower Pots, Jars, and other Vessels from Semi-plastic Materials.
1, WILLIAM WEST, of 18, Albion Street, Leeds, in the County of York,
Tailor and Draper, do hereby declare the nature of this invention to be as
follows:-
Amongst other matters this invention deals with the difficulties which are
encountered in removing the pressed articles from the moulds.
I use a central core of suitable shape for forming the interior of the vessel,
fixing it on a suitable head with its nose pointing downward.
On an upper
parallel part of this core I mount a closely fitting sleeve whose lower rim is
shaped to form the brim of the vessel. To this sleeve I give, say by gravity or
by springs, a power of advancing down the core through a suitable distance which
may be regulated by stops. A contrary stronger pressure against the rim will
again raise the sleeve against an upper stop.
Below the plunger I arrange an outer-mould, shaped to suit the exterior of the
vessel, and I mount it on a suitably guided frame which works up and down in a
true line with the centre of the overhead core. The base of this outer mould is a
sparute piece, fitted with a central spindle, suitably guided below, and it is so
ranged that it can advance into the interior of the mould and so effect the
ection of the contents.
When this base rests in its lowest position in the mould it does so on a mitred
Ige, so that the whole bottom is airtight as long as the base is held down on its
valve-like seat; otherwise the bottom of the mould is open.
"
Supposing now the proper weight of plastic material to be placed in the
ter-mould and the whole advanced to a pre-arranged point against the
Overhead core.
It will follow-secing that the rim of the sleeve fills the brim of the
oter-mould-that a semi-plastic vessel will now have been pressed into shape.
The difficulties may now be said to begin :-Under ordinary but favourable
rcumstances, on withdrawing the mould one of two things will happen; (1) either
the vessel will draw away along with the outer mould, the atmosphere then entering
and holding it there, or (2) the vessel will remain on the central core, with the
surrounding atmosphere pressing it tightly thereon.
My apparatus is arranged to compel the vessel to leave the core, and adhere to
the outer-mould, in every case, and this I accomplish, first, by the action of the
brim-forming sleeve which follows down along with the descending mould until the
atmosphere has entered between it and the core, and second, by arranging that
the base of the mould shall be tightly held down on its valve-like seat at this
important time, so that the atmosphere has no opportunity of entering below and
so releasing the vessel from the mould.
The holding down of this base is accomplished by making it or its spindle
advance at the far end of the stroke against a stop governed by a spring or by
gravity, and the recoil of this during the corresponding part of the return stroke
effects the desired object.
Now that the atmosphere is inside the vessel, with a vacuum behind the clay
under ordinary circumstances-it follows that it will be difficult to eject the vessel
without spoiling it.
To assist me in contending against this 1 arrange a supply of heat to the mould,
and as the tendency of this, acting on the damp semi-plastic material, is to lead to a
slight vapour being formed, it follows that the strength of the vacuum will be thereby
more or less vitiated or destroved.

page_text: Hence, when, by any suitable action the base is raised, and air thus admitted all
round its valve-like periphery, the ejection is accomplished without difficulty;
nevertheless the condition of the clay must be dry enough to leave a solidly
compressed vessel, otherwise it will be spoilt by the necessary ejecting pressure.
The ejector raises the vessel high enough out of the monild for the attendant to
take it away.
The machinery for advancing the would against the central core is of secondary
importance as it can be necomplished by a variety of means,
Anti-factory way because simpler than using an hydraulic or other press,
a less costly than using a revolving table with multiple moulds, is got by
using a ba-e-plate from out of which spring two steel or wrought iron straining
posts.
At the top of these posts is fixed an adjustable stationary cross-hend on which is
mounted the central core which carries the brim-forming sleeve.
These posts also form the guides for the lower frame which carries the outer
mould.
The upper ends of a set of toggle levers are attached to this moving frame
whilst their lower ends are connected below with the ha-e-plate. A connecting rod
netuated by a suitably geared crank moves the toggle levers in and out of line with
the guide posts, and thus the main parts of the press and its movements are
olitainet.
'
As th lower eros-head descends, he ejecting spindle comes in contact with a
stop which cafeets the ejection.
When lower pots are made a central spindle with a limited movement may be
carried down inside the overhead core. and thus the base of the ejector may be
held down, from above, at this all important time otherwise this must be done
from below.
The noe of the central core may, in some cases, require a revolving or twisting
movement to be given to it, just as the withdrawal commences, to detach any
material that may have a tendency to adhere to it. In such a case I introduce a
central rocking spindle down the central core, or otherwise revolve the nose of
the core.
The semi-plastic material is best introduced into the mould in an annular form, a-
this assists the nose of the core to retain its share of any lubricant used to effect a
clean separation of the vessel from off' it.
In some cases air may with advantage be admitted at the foot of the central
core.
Heat may in some cases also be applied inside the central core.
Although the application of heat decreases the amount of lubrication, required to
release the material from the mould &e., I do not find continuous work to be
satisfactorily accomplished without soine lubrication. In order however to avoid
stopping the machine to lubricate the core, mould, and have, I make a semi-elastic
porous russel of the shape required, and after dipping it in the lubricant I introduce
it into the mould and give it a press against the core this from time to time as
required. Or a moulded semi-plastic vessel may be dipped in a lubriennt and may
then be given a second squeeze, this both lubricates the moulds for the next vessel
and gives a superior finish to the one this used; this second pressing of a vessel coated
with a lubricant may be carried out systematically.
Any semi-plastic lubricant, say bee's wax &c., such as has the power of
retaining its moulded shape, may be used in a similar way as a lubricating
vehicle ; a little more material being added to it from time to time to supply that
given off.
T
1
11000

page_text: COMPLETE SPECIFICATION.
An Improved Mode and Apparatus for Manufacturing by Pressure
Flower Pots, Jars, and other Vessels from Semi-plastic Materials.
I, WILLIAM WEST, of 18, Albion Street, Leeds, in the County of York, Tailor
and Draper, 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 :-
1. Amongst other matters this invention deals with the difficulties which are
encountered in removing the pressed articles from the moulds.
2. I use a central core of a suitable shape for forming the interior of the vessel
fixing it on a suitable head with its nose pointing downward. On an upper parallel
part of this core I mount a closely fitting sleeve whose lower rim is shaped to form
the brim of the vessel. To this sleeve I give, say by gravity, or by springs, a
power of advancing down the core through a suitable distance which may be regulated
by stop. A contrary stronger pressure against the rim will again raise the sleeve
against an upper stop.
3. Below the plunger I arrange an outer-mould, shaped to suit the exterior of the
vessel, and I mount it on a suitably guided frame which works up and down in a true
line with the centre of the overhead core. The base of this outer mould is a
separate piece, fitted with a central spindle, suitably guided below, and it is so
arranged that it can advance into the interior of the mould and so effect the
ejection of the contents.
4. When this base rests in its lowest position in the mould, it does so on
a mitred edge, so that the whole bottom is airtight as long as the base is held down
on its valve-like seat; otherwise the bottom of the mould is open.
5. Supposing now the proper weight of plastic material to be placed in the
outer-mould and the whole advanced to a pre-arranged point against the overhead
core.
6. It will follow, seeing that the rim of the sleeve fills the brim of the outer-
mould, that a semi-plastic vessel will now have been pressed into shape.
7. The difficulties may now be said to begin. Under ordinary but favourable
circumstances, on with-drawing the mould one of two things will happen; (1) either
the vessel will draw away along with the outer mould, the atmosphere then entering
and holding it there; or (2) the vessel will remain on the central corc, with the
surrounding atmosphere pressing it tightly thereon.
8. My apparatus is arranged to compel the vessel to leave the core, and adhere
to the outer-mould in every case; and this I accomplish, first, by the action of the
brim-forming sleeve which follows down for some little distance along with the
descending outer mould until the atmosphere has entered between it-the vessel-and
the core and, secondly, by arranging that the base of the mould shall be tightly
held down on its valve-like seat at this important time, so that the atmosphere
has no opportunity of entering below and so releasing the vessel from the mould.
9. The holding down of this base is accomplished by making it or its spindle
advance at the far end of the stroke against a stop governed by a spring or by
gravity, and the recoil of this during the corresponding part of the return stroke
effects the desired object.
10. Now that the atmosphere is inside the vessel, with a vacuum behind the
pressed material under ordinary circumstances: it follows that it will be difficult
to eject the vessel without spoiling it.
11. To assist me in contending against this I arrange a supply of heat to the
mould, and as the tendency of this, acting on the damp semi-plastic material, is to
lead to a slight vapour being formed, it follows that the strength of the vacuum
will be thereby more or less vitiated or destroyed.
12. Hence, when, by any suitable action the base is raised, and air thus admitted

page_text: all round its valve-like periphery, the ejection is accomplished without difficulty;
nevertheless the condition of the material must be dry enough to leave a solidly
compressed vessel; otherwise it will be spoilt by the necessary ejecting pressure.
13. The ejector raises the vessel high enough out of the mould for the attendant
to take it away.
14. In order to facilitate the entry of air to the inside of the moulded vessel, when
it is being withdrawn from of the central core, a series of perforations are made us
near as practicable to the edge of the brita-forming-sleeve, so that there may be a
supply of air all round the core.
15. Should the material to be pressed contain any air, or hould the mode of
feeding it into the mould entrap air, it will be found necessary to provide an outlet.
at the base; nevertheless great care must be exercised to so arrange this outlet that
no air is readmitted thereat.
16. The central con, the outer mold, and the ejecting base must, of course, be
so shape that they will withdraw from off, or out of, the mouldel vessel, but they
neel not arily be circular, in plan: although a circular ejecting base has the
advantage of being easily made and kept airtight.
17. The machinery for advancing the mould against the central core is of
secondary importance as it can be recomplished by a variety of meats,
18. A satisfactory way, because simpler than using an hydraulic, or other press,
and less costly than using a revolving table with multiple mould, is got by
using as-plate from out of which spring two steel or wrought iron straining
10-1-
19. At the top of these posts is fixed an adjust: ble stationery cross-head
on which is mounted the central core which carries the brim-forming-leeve.
20. These post also form the guides for the lower frame which carries the outer
mould.
21. The upper ends of a set of toggle levers are attached to this moving frame,
whilst their lower ends are connected below with the base‐plate.
22. A connecting rod actuated by a suitably geared crank moves the toggle lever,
in and out of line with the guide posts, and thus the main parts of the press and its
movements are obtained.
23. As the lower cross head de-cends, the ejecting spindle comes in contact with
a stop which effects the ejection.
24. When flower pots are made a central spindle with a limited movement may be
carried down inside the overhead core, and thus the base of the ejector may be held
down from above at the all important time-otherwise this must be done from
below.
25. The nose of the central core may, in some cases, require a revolving or
twisting movement to be given to it, just as the withdrawal commences, to detach
any material that may have a tendency to adhere to it. In such a case I introduce
a central rocking spindle down the central core, or otherwise revolve the nose of
the core.
26. If the semi-plastic material to be pressed is of a very unyielding nature it
may be introduced into the mould in an aumular form, as this assists the nose of the
core to retain its share of any lubricant placed thereon to effect a clean separation
of the vessel from off it whilst this said form requires a less pressure to make it
fill the mould.
27. In some cases air may with advantage be admitted at the foot of the
central core in order to prevent a vacuum being formed when the withdrawal takes
place.
28. Heat may in some cases also be applied inside the central core, when not
revolved, but revolving is preferable; stenm may here be used.
29. Although the application of heat, previously mentioned, decreases the amount
of lubrication required, or at any rate assists in releasing the material from the
mould, and, further, by drying it, enables it to more effectually withstand the
ejecting pressure without bulging out of shape, I do not find continuous work to be

page_text: satisfactorily accomplished without some lubrication. In order however to avoid
stopping the machine to lubricate the core, mould, and base, a semi-elastic porous
vessel of the shape required may be smeared with, or dipped into, a lubricant, and
afterwards introduced, from time to time, into the moulds, thereby lubricating the
whole.
30. Or one of the already moulded semi-plastic vessels may be (1) lubricated,
and (2) replaced in the moulds, and be given a second squeeze; this both
lubricates the moulds and gives a superior finish to the one thus used; this secondl
pressing of a lubricated vessel may be carried out systematically thus:-
31. Instead of pressing a vessel twice in the same mould, I pass it through two
sets of moulds, the first of which forms it into a comparatively thick vessel well
able to withstand ejection.
This opens up a further opportunity for lubrication so that when put into the
finishing moulds it can be easily formed into a vessel with sides and bottom of the
requisite thinness.
32. It is worthy of note that when a vessel is thus pressed (in two or more
operations) little or no heat need be applied to the moulds. As the application of
heat has its disadvantages, owing to its expanding the ejector base, &c., this latter
mode of proceedure is the more valuable and the one I recommend whenever it can
be carried out.
33. The condition of the material should be such that its softness will allow it to
be easily pressed into shape, but it must nevertheless be sufficiently dry to enable
the pressed vessel to be ejected without damage from bulging, &c. It must of
course be drier than the material usually used on the potter's wheel. The pressed
vessels are soon dried and are therefore sooner ready for the kiln.
When the material is to receive two or more squeezes it is best fed into the
moulds in a flat-cheese shape, such cheeses being smeared on the top and bottom
with a lubricant (common brick yard oil" will do). Between any two squeezes
further lubrication is easily effected.
In order to fully explain my invention and the mode of operating and carrying it
into effect I have annexed four drawings. The same letters refer to the same parts
(or their equivalents) in all the figs.
Fig. 1 is a general plan with the upper crosshead, &c. removed; and Fig. 2. is
a corresponding side elevation.
Fig. 3 is a side elevation of the upper crosshead and head-piece etc.; and Fig. 4
is a corresponding front elevation.
Fig. 5 is an elevation of the lower parts of the front, being a continuation
of Fig. 4.
Fig. 6 is a plan of the upper crosshead, and Fig. 7 a plan of the worm and worn
wheel bracket for revolving the central core-fitting thereon, and into which the
central core barrel is screwed.
Fig. 8 is an enlarged sectional elevation showing the ejector base, &c. and Fig. 9
shows the ejector apart.
Fig. 10 shows an arrangement for holding down the ejector from above—at the
time the outer mould is being withdrawn-when the central core is not revolved,
and Fig. 11 shows a mode of doing this when the core is revolved. Many parts of
the drawings are sectioned for explanatory purposes.
A is the central core or plunger; B the crosshead; C the brim-forming-sleeve;
D are the springs (adjustable); and D₁ the regulating stops; whilst the
crosshead B forms the upper one; all referred to in paragraph 2.
E is the outer-mould: Fis the moving-frame; G is the ejector, and Gits
central spindle guided at (and G, referred to in paragraph 3. H is a ring of
gas jets to supply the heat referred to in paragraph 11; this gas arrangement for
heat allows the moulds, E, to be easily interchanged. The ring may rest on a
duplex cramping bar J. This latter when screwed down presses down the guiding
bracket of the ejector spindle, for convenience bolted to the foot of the outer
nould, and so holds all tightly in position.

page_text: Referring to paragraphs 12 and 13, the ejecting base may be raised, see Fig. 2.
by the counterbalanced lever K, which is coupled to the said base, striking the toe
of the tappet, 1, attached to the lower toggle lever: as soon as this release is
given the counterweight carries the moulded vessel to the desired height out of the
mould a chain K¹ for regulating this being provided.
M, M. are the air holes in the sleeve C. referred to in paragraph 14, and internal
grooves may lead the air still nearer to its work. In Fig. 8 and 9 air passages
may be eat in the valve-like seat of the ejector so as to supply air quickly when
the base is once raised.
Referring to paragraph 15, in Fig. 8, N. is the smell air outlet. This permits
air to escape into the open-ended hollow spindle (of the ejector, and as the hole
is closed by the material pressing therein after the exit of the air, and as the hole
is small in proportion to the length of the escaping channel, and the taper allow
the escaping material to expand and waige itself, no rntry of rir tak place.
O is the base plate, and P, P. are the straining post referred to in paragraph 19.
whilst a Q'are the upper and lower toggle lovers of paragraph 21,
Ris the connerting rod, of paragraph 22, which couples the eutral toggle joint
to the erenk in R. This pin is fixed on the wheel S, which is driven by the
pinion S mounted on the fir-i motion shaft, SF, whereon are mounted fast and lonse
driving pullies Sand St. A fly wheel inay be mounted at S when necessary.
The lower toggle joint Q' has its bearing in the bracket, T, which is held in its
place by the two-training and guide posts P, P. The latter P, P, run through
to the top of the machine so that all heavy strains are dealt with by these rol.,
whilst their nuts permit various adjustments to be made.
Referring to paragraph 24, Fig. 10 shows a central spindle running through the
central core, connected, for convenience, to the brim-forming-sleeve, and its prings
(not shown); this ensures the holding down of the ejector base when the inmuild
commences to retire from the central core. Fig. 11 shows a modified form of this
arrangement suited for case in which the central core is revolved; here the
gjecting base when pressed home compresses the spring D which re-asserts itself
by pressing the central spindle down on to the bases the withdrawal commences,
When this holding down pressure on the ejecting base is given from below, as it
must be in making cups bowls &c. &c. with a solid bottom, the arrangement shown
in Figs. 2 & 3 is applicable: here the ejecting lever is provided with adjustable
rods l” which extend upwards towards the flange of the brim-forming-sleeve and
are actuated by the springs of the latter. Other modifications may be arranged
the requirement being that some recoiling force shell be provided and brought
into play for a short distance when the mould commences its return -troke.
a vertical
With reference to paragraph 25, V is a pulley on the first motion shaft driving
belt which in its turn drives an overhead pulley mounted on the worm
shaft The worm (1) drives the worm wheel 'V' mounted on
shaft which extends downwards, through a guiding barrel V, and revolves the
central core.
Under extra heavy pressure the belt slips and relieves the revolving
gear from strain. The head piece W is introduced to carry a pin W' to take the
thrust of this vertical central shaft, so as to reduce friction when revolving under
pressure. Counter-weights, X, X, may be used to balance the moving frame or
crosshead.
A back-stay Y steadies the upper part of the machine.
The toe of the tappet is arranged to pivot on the centre L' which is easily
adjusted (1) by slotted holes and the studs L L and also (2) by the supporting
bolt L. This pivoting allows the toe to give way-upwards-if from any cause
the lever K gets under it, the spring 1 drawing it back to its proper place.
I prefer to make the bolts in the connecting rod end very light so that they may
give way without further damage being done should anything hard get into the
mould.
The ejector base instead of being flat, may have projections, or depressions,
arranged thereon, in order to produce corresponding formations in the base of the

page_text: vessal; in any case I prefer to raise, or cup, the outermost elge of the eject,
se Fig. 8. The rim of the brim-forming sleeve I prefer to make somewhat
enpped also see Fig. 3.
Many of the details may be altered if the points herein set out are carefully
rttended to. All parts needing it should have adjusting nuts as shown. The
maus operandi is as follows:- lump of material of the proper weight is placed
on the ejecting base C, and the moving crosshead is advanced against the
overhead core A; when the central toggle joint has reached the vertical line
(taking this arrangement as an example) everything will have been pressed home,
and a pressed vessel will be enclosed in the mould, see Fig. 3. The head of the
brim-forming sleeve C has been thrust against an upper stop (the crosshead B.);
whilst the lower rim has fully entered the mould, as shown the springs, D, are
compressed; and the rods, U, U, whose duty is to hold down the ejecting base, are
in close contact with the flange of the sleeve C. Hence when the crosshead F
commences to retire two important movements at once commence; first, the
sleeve C, actuated by the adjustable springs D, follows down and continues the
pressure on the rim of the moulded vessel, thus keeping it in the mould whilst
permitting the core A to withdraw; and, secondly, the rods, U, U, in moving
down under the spring pressure continue to be held down tightly and therefore in
turn hold down the ejector. This continues until the flange of the sleeve (
reaches the adjustable stops D', by which time air has entered between the core A
and the vessel in the mould. The downward movement of the crosshead
continuing, the roller on the end of the counterweighted lever, K, see Fig. 2
"oines in contact with the toe of the tappet L when it is jerked somewhat suddenly
upwards, the vessel being delivered ready for the attendant to remove.
The crank should revolve in the directions shown by the arrow. During this
whole time the belt will have been revolving the central core.
In Fig. 3, 10, and 11, the brim-forming-sleeve is shown in its lower position,
laving advanced automatically downward.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
.
(1) The herein explained mode (applied both to single and multiple pressings)
of manufacturing flower pots, jars, and other hollow vessels; consisting essentially
of feeding semi-plastic material, suitable for the work, into an outer mould, which
is, first, advanced against an overhead central core (or inner mould) on which is
mounted a brim-forming-sleeve, or ring, which retreats to its utmost extent before
the material in the mould when the squeeze is given then, secondly, when
the withdrawal of the said onter mould is commenced, the said brim-forming-sleeve,
or ring, automatically advances (to the extent necessary) and assists in pushing
the then moulded vessel from oif the central core, or, otherwise, assists in holding it
in the said outer mould; the ejecting base of the said outer mould being meanwhile
mechanically prevented from rising off its valve-like seat at this all important
time; after which, thirdly, when the moulded vessel has been ultimately left in the
outer mould, and this latter has been sufficiently withdrawn, a sudden push is given
to the ejecting base, so as to raise it quickly from off its seat, and thus eject the
vessel.
(2) In pressing hollow vessels from semi-plastic materials the use of an
automatically worked brim-forming-sleeve, or ring, mounted and working on, or
concentrically with, the central core, for the purpose of assisting the said central
core to clear itself from, or out of, the moulded vessel, or, otherwise, of assisting in
keeping the vessel in the outer mould, after the manner set forth.
(3) The use of an automatically worked brim-forming-sleeve, as in Claim 2,
arranged so that the nose of its central core may revolve under all but excessive
pressure, after the manner set forth.

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(4) The combination of (1) an automatically worked brim-forming-sleeve, or
ring, mounted and working on, or concentrically with, (2) a central core,
with (3) an outer mould, fitted with (4) an ejecting-base having a valve-like seat
at the base of the said outer mould, with the object and for the purpose set forth.
(5) The combination of parts set out in Claim 4 supplemented by (1) the toggle
lever arrangement for moving the frame which carries the unter mould, and (2) an
ejecting tappet carried in and out by the toggle levers, with the object and for the
purpose set forth.
(6) The combination as in Claim 5, supplemented with the swivelling-back tappet
arrangement, shown on Fig. 2, with the object and for the purpose set forth.
(7) The combination of parts set out in Claim 5 supplemented by a counter-
weighted ejecting arrangement for giving rapidity to the ejection, with the object
and for the purpose set forth.
(8) The combination of ports set out in Claim + supplemented by gear for
holding down the ejecting base at the time when the vessel is being withdrawn
from off the central core, with or without the non-return air escape tube shown in
Fig. 8, with the object and for the purpose set forth.
(9) The machine herein set forth, arranged, constructed, and operated sub-
stantially as described and shown, with the oljeet and for the purpose set forth.
Datel this 30th day of January 1891.
WM. SNOWDON,
9. Old Bank Chambers, Leeds, York, Agent for the Applicant.