Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
53S
The present invention refers, in a very general way,
to a mould for casting hygienic-sanitary apparatus in "vitreous
china" and more particularly it concerns a mould for casting
articles with integral rim, the latter either closed or open.
For example, such articles can be water closet bowls, bidets
or other similar apparatus.
It is noted that these latter are cast in complex
moulds which are composed of a series of mould parts that can
be assembled one with the other to form a casting cavity in
which a ceramic material is introduced in slip form.
Amongst other things there are known casting moulds
which comprise a lower mould part suitable for shaping the inner
cavity of the pedestal of th.e article to be cast, two side mould
parts suitable for being closed on said lower mould part
according to a horizontal movement and intended to shape the
article externally, and an upper mould part or cover which is
intended to be placed on the side mould parts to close the upper
opening of the casting cavi.ty defined by the aforesaid lower and
side mould parts.
The aforesaid cover, in plaster lik.e the other mould
parts comprising the mould, is normally constituted by a flat
body whose perimetral edge is supported on the upper faces of
the side mould parts wh.ilst from its lower face there projects
a sinker which penetrates a certain distance inside the casting
cavity of the mould. The lower end of this sinker may be flat
or may be provided with a depres~ion generally shaped like a
dome, which faces towards the said casting cavity. This lower
end in addition is usually covered ~y a thin resinous synthetic
layer, impermeable to air, or is constituted by a synthetic
insert which is embedded in the plaster of the cover.
In addition, the side wall of the sinker of this latter
is spaced by a certain distance from the upper edge of the inner
surface of the side mould parts so as to thus constitute~in the
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finished article, with the combination of said upper edges of
the side mould parts and lower face of the cover, an integral
rim of the open type.
The casting moulds of the above described type,
however, although at present widely used, have shown, and still
show, the disad~antages that will be briefly listed below.
These latter are practically totally due to the shape of the
aforesaid cover and upper edges of the side mould parts.
In fact, because of the fact that the uppex horizontal
and inner vertical walls of the rim are intended xespectively to
be formed on the lower face of the cover and against the side
face of the sinker of this latter, in the course of taking the
article out of t~e mould, and more precisely in the course of
lifting the cover, in certain cases they cause damage to the
rim that has just been cast, in particular in correspondence
with the point of contact of its horizontal wall with the wall
cast on the side mould parts, with the serious and obvious
consequences which result from it.
This obviously is due to the extremely extended face
of the cover against which there is cast and attached the rim
that is not yet fully hardened and hence not yet sufficiently
resistant to the shearing force due to the raising of the cover.
In addition, another disadvantage of the known casting
moulds derives from the fact that the surface of the cover,
subject to the hydrostatic force of the slip put in hy gravity
in the mould, is excessive and so the resultant force which
tends to raise the cover, is relatively great and so as to
maintain this latter constantly supported against t~e side
mould parts it is necessary to prepare vertical clamping devices
of the moulds which are suitable for counterbalancing said
relatively great forces.
As a direct conse~uence of this, these vertical
clamping devices must of necessity be strong, complex and costly,
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taking into account that usually hygienic-sanitary apparatus
is cast in correspondence with a casting installation or bench
which also comprises fifty or more casting moulds.
Besides, a cover of the type described is extremely
clumsy and heavy and hence awkward to lift and to manoeuvre by
the operator. The present patent of invention proposes to
present and protect a mould for casting hygienic-sanitary
apparatus with integral-rim which, within the scope of a simple,
functional, rational and extreme.ly reliable constructional
solution, finds a remedy for the above disadvantages.
According to the invention the casting mould proposed
is of the type comprising a lower mould part, suitable for
shaping internally the pedestal of the article to be cast in
the mould, two side mould parts suitahle for being closed on
said lower mould part according to a horizontal movement of
reciprocal bringing-together, and is characterised by the fact
that these latter are individually provided, on the top, with
a perimentral bracket which projects towards the central zone
of the mould and on whose lower face there is formed, during
the casting stages, the horizontal upper wall of the integral
rim of the articles.
Finally, the above-mentioned brackets are provided on
the top with a widened shoulder-like abutment which acts as a
seat for a closure insert which, when the mould is a~sembled,
closes the aperture defined by said two brackets.
In addition, said closure insert suitable for being
inserted a certain distance inside the casting cavity defined
by aforesaid side and lower mould parts, is advantageously
constituted by a core of light material, for example an expanded
synthetic material which is laterally covered with a suitable
layer of plaster in which.there is formed the inner wall of the
integral rim, this being of the closed or open type.
~he aims and advantages of the invention, together with
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its characteristics and its constructional values will be better
clarified and proved more clearly in the light of the detailed
description that follows which is made with reference to the
Figures in the only sheet of drawings attached which illustrates
a particular and preferred form of embodiment, but are given
merely by way of non-limitative example.
Figs. 1 and 2 show two vertïcal sections, at right angles
to each other, of the upper part of an assembled mould like the
invention.
Fig. 3 shows, according to a perspective ~ie~, the same
upper part of the mould with the closure însert in the extxacted
position.
From the above figures it can be seen that in this there
has been shown only the upper part of a plaster mould for casting
a ceramic material in sl;p form so as to form hygienic-sanitary
apparatus like, for example, water closet bowls, bidets and other
similar articles.
From the particular shape of the upper part of the mould
in question it is noted also that this is of the type suitable
for the casting of hygienic-sanitary apparatus with integral
rim. The latter may be of the open type, as can be seen from
the attached drawings, but it can also be of the closed type as
will be further described.
The invention is composed of a lower mould part, not
shown, which is intended to shape the inner zone of the pedestal
of the article which is to be cast inside the same mould. This
latter in addition comprises two side mould parts 1 , symmetrical
with one another, which are constituted from plaster like the
lower mould part just mentioned.
These side mould parts 1 are intended to be held on
the lower mould part according to a horizontal movement of
reciprocal bringing-together so as to shape the outer faces of
the corresponding hygienic-sanitary apparatus.
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From the perimetral upper edge of the inner face of each
side mould part 1 , see Figs. 1 and 2, there projects a
perimetral ~racket 2 which extends a certain distance towards
the central ~one of the casting cavity which is defined by the
said side mould parts 1 and lower mould part.
The inner edge of the perimetral brackets 2 is slightly
flared upwards whilst their upper corner is crossed by a widened
shoulder-like abutment 3 .
When the mould is assemhled the two perimetral brackets
2 define an aperture 66 which is closed by means of a closure
insert 4 .
According to a plan view, the closure insert 4 has a
generally oval shape which matches exactly the aperture 66
above mentioned.
The closure insert 4 comprises a central core 5 in
light material like, for example, a synthetic expanded material
whose upper part is surrounded by a suitable easing depression
which in its turn is transverseIy provided with a stiffening
flange 98 .
The side wall of the synthetlc core 5 is covered with
a suitable thickness in plaster 7 , the outer face of which has
an incline which is substantially coincident with the incline
of the inner edge of the psrimetral brackets 2 .
This layer of plaster 7 is provided at the top and
peripherally with a lip 6 which is suitahle for contacting the
widened shoulder-like abutment :3 of the brackets 2 when the
mould is assembled. In add;tion the lower face of the synthetic
core 5 is constituted by a concave depression 8 , generally
dome-shaped, the concavity of which is turned towards the casting
cavity where the hygienic-sanitary apparatus is to be cast.
Obviously the synthetic material which comprises the
core 5 can by a synthetic material impermeable to air or can
also be a material that is permeable to air, which is covered,
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at least in correspondence with the surface of the dome 8 , with
a suitable resinous synthetic layer, impermeable to air.
In the course of use of the casting mould in question, on
the lower mould part of the mould there are assembled, by means
of a horizontal movement of reciprocal bringing-together, the two
side mould parts 1 which are successively clamped in the lateral
or horizontal direction.
Consequently, in the aperture 66 which defined the upper
opening of the casting cavity in the mould, there is inserted the
closure insert 4 which is then pressed against the brackets 2
by means of a vertical clamping device.
This latter, as clearly shown in the enclosures figures,
is composed of a metallic arm 96 which at one end is hinged to
a small piller 94 . At the opposite end the arm 96 is provided
with a seat 86 for hooking a ~econd small pillar ~92 , this
latter with an enlarged head. The pillars 94 and ~2 project
from the upper faces of the side mould parts 1 and are symmet-
rically disposed either relatively to the vertical dlviding
plane of these latter or with respect to a vertical plane which
is at right angles to said div;ding plane. Finally, the arm 96
is provided with two threaded gripping pins 82 , individually
provided with an upper actuation crosspiece, the lower ends of
which, intended to act on the flange ,98 , have pressure plates.
At this point the mould is ready for casting and, through
a suitable channel which normally is provided in correspondence
with the lower mould part of the mould, inside the casting
cavity defined by the mould parts which constitute the mould,
some slip is introduced by gravity. This latter rises upwards
inside the aforementioned casting cavity, displacing the air
present in it which leaves through normal vents whic~ are in
correspondence with the common separation plane of the side
mould parts.
It will certainly be noted that the closure insert 4
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extends inside the casting cavity for a certain distance the slip
continues to rise until it reaches the lower end of the closure
insert 4 .
At this point it is necessary to state, even if not
mentioned before, that the lower opening of the dome 8 is
slightly inclined, for which reason, during the aforesaid casting
stages, the casting mould is disposed with an incline suitable
for positioning horizontally the aforementioned opening of the
dome 8 .
When the ceramic material in slip form arrives in corres-
pondence with the above mentioned opening it continues to rise,
completely filling the annular cham~er which is compressed
between the closure insert 4 and the upper ends of the inner
suxfaces of the side mould parts 1 . In this way the mould is
completely filled with slip with the exception of almost the
whole of the dome 8 where there is trapped a certain quantity
of air which i8 at the same pressure as the hydrostatic charge
of the slip coming from a conventional and overlying supply tank.
More precisely, since the air is a compressible fluid, the
free surface of the slip which is placed in front of the dome
8~ also affects for a short perimetral distance the surface of
the dome 8 , said short distance being a function of the
hydrostatic charge of the slip.
The mould thus filled is left to rest for a specific
period of casting during which, on the mould parts which con-
stitute the mould, there are formed the walls of the article
since the plaster which constitutes the aforesaid mould parts
absorbs the moisture of the slip.
More precisely, in correspondence with the annular
chamber which is defined by the closure insert 4 and ~y the
upper ends of the side mould parts 1 there is formed the
integral rim, of the open type, of the corresponding article.
Besides, the closure insert 4 is intended to define
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the aperture of the bowl of said article.
In fact, in correspondence with the upper perimetral
edge of the inner surfaces of the side mould parts 1 there is
formed the outer wall of said open integral rim whilst, on the
other hand, respectively in correspondence with the outer
surface of the plaster rillg 7, there are formed the upper
horizontal wall and the inner wall of said open integral rim.
After the above speci.fied period of casting has passed,
through the same aperture for casting there is effected the
drainage of the mould which may occur simply by gravity or can
be actuated also by using compressed air which is inserted in
the upper zone of the mould in known ways, this latter type of
drainage being particularly advantageous for accelerating
drainage and for preventing possible whirlpool effects wh.ich are
extremely damaging for the walls that have just been cast.
At a certai.n point in thi.s drainage the free or level
surface of the slip bath present inside the casting cavity of the
mould completely frees the lower opening of the dome .8 and
substantially at this point the drainage operation is stopped
for a certain time to let the closure insert 4 drip and to
prevent this dripping from damaging the integrity of the bowl of
the article just cast.
Hardly has this dripping stopped than the drainage
operation is brought to an end and then one proceeds to take out
the article from the mould. This final drainage can be brought
to an end by removing the closure insert from the side mould
parts.
As a result of the full descri.ptive relationship given
previously one will certainly note great advantages made available
by a mould thus equipped but, so as to avoid wrong interpretations
or useless obscurities, said advantages will be briefly listed as
follows. A first major advantage is due to the fact that with a
mould thus shaped it is practi.cally impossible, during the
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extraction of the closure insert 4 , to damage the integral rim
of the article since the inner wall of said rim is supported
against the lower face of the perimetral brackets 2 .
Another great advantage is due to the fact that hydro-
static pressue due to the liquid charge of the slip during the
casting stages is not discharged completely on the closure insert
4 but a great part of it i5 supported ~y the ~rackets 2 which
are monolithic with the side mould parts 1 .
For this reason, in correspondence with a casting
installation or bench, it is possi~le to prepare ver~ical clamping
devices much less sturdy, less complicated and hence less costly
than those known, for example of the type shown in the enclosed
figures.
Further, thanks to the lightness of a closure insert 4
thus constituted, the operators are greatly helped and the
manipulations of the closure inserts 4 are made less heavy and
this also in relation to their inconvenience which is relatively
contained with respect to the known prior art.
Finally, the presence of the dome 8 is extremely
advantageous since during the casting stages only a small edge
which is close to its mouth is wetted by the slip so that the
cleaning operations of said dome that are necessary before
proceeding to a subsequent casting stage, are considerably
~implified.
However, it is not necessary that the invention provides
a closure insert 4 provided on the ahove-mentioned dome 8 .
In fact, for example, a mould thus constituted is just as efficient
for the casting of hygienic-sanitary apparatus with integral closed
rim.
For this purpose it is sufficient with the invention to
provide an upper mould part known per se which comprises a flat
annular body suitable for being placed on the side mould parts 1 ,
a projection which projects centrally from the lower zone of said
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flat annular body to close the aperture 66 and a removable
collar, placed laterally of the area of attachment of said
projection to the flat annular body, which is composed of a
seri.es of separate plaster parts which are individually generally
like a wedge or a tooth.
During the casting stages the aforementioned removable
collar is supported by suitable coupling means which are put on
the lower face of the flat annular body of the upper mould part
of the mould.
In this above-described case there is provided, on the
projection of the upper mould part, a seat suitable for receiving
the correct positioning of the remova~le collar, the upper.flat
surface of which, as is know, is intendedl during the casting
stages, to form the lower horizontal wall of a closed integral
rim.
Qbviously for the æame reasons gi.ven above in this
specific case also, i.e. hygi.eni.c-sanitary apparatus with closed
integral rim, the upper central zone of the mould is constituted
as is shown in the attached figures.
However, it is not necessary for the upper mould part of
the mould to comprise a central core .5 covered by a plaster
thickness 7 but it can simply be constituted by a full shaped
body, in plaster, suita~ly e~uipped to receive the above-
mentioned ~emovable collar.
It is understood that the invention is not limited
merely to the embodiments descrihed above and that variants and
improvements can be brought in without, however, departing from
the scope of the invention, the fundamental characteristics of
which are summarised in the following claims:
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