[0001] The present invention patent relates in an entirely general manner to a mould for
casting a ceramic material of slip form. More particularly, it relates to a mould
for casting sanitary appliances in which separate mould parts are required to remain
suspended, for example a mould for forming sanitary appliances with a closed integral
rim such as water closets, bidets or urinals, or generally with internal projecting
undercut parts, such as a rib or undercut edge an example of which is an anti-drip
edge.
[0002] For casting such articles, plaster moulds of the built-up type are known inter alia,
which usually comprise a lower mould piece, lateral mould pieces arranged to close
together on said lower mould piece to define a moulding cavity, an upper mould piece
arranged to close said moulding cavity and provided lowerly with a core arranged to
shape the inner part of the bowl of the article, and a collar or another analogous
mould part or section for disposing in a removable manner at the base of said core,
and which can either be divided into a group of separate parts or can be in one piece.
[0003] For example, the upper faces of said separate parts can be designed to form the lower
wall of a possible integral rim closed by the appliance cast in the corresponding
built-up mould, or a possible projecting edge inside the appliance. When the mould
has been assembled, i.e. during the casting stages, the parts which constitute said
separate mould part are supported by said upper mould piece by means of suitable coupling
means.
[0004] In certain cases, these coupling means are in the form of one or more springs for
each separate mould part, these being housed in suitable apertures provided in the
upper mould piece, and being hooked to the corresponding part at one. end, whereas
their other ends comprise a hook or a cross-bar.
[0005] Said hook and cross-bar are designed respectively, when the spring is under tension,
to be hooked to a suitable member of the upper mould piece or to be disposed transversely
relative to the aperture housing the corresponding spring.
[0006] In other cases, the aforesaid coupling means are in the form of threaded members
which traverse the upper mould piece to reach and support the underlying separate
parts which constitute said collar.
[0007] In further cases, said coupling means are essentially constitut-
ed by rings of metal wire used together with hooks, wedges or other similar elements.
[0008] The continuous widespread use of the known moulds equipped in this manner has however
brought to light drawbacks which are briefly listed hereinafter, and which are due
practically entirely to the means for coupling the separate mould part or parts.
[0009] These drawbacks arise from the fact that the coupling and uncoupling of said coupling
devices require excessively long times and are complicated, and in certain cases are
not sufficiently precise.
[0010] Moreover, the larger the number of separate mould parts, the larger the number of
coupling devices necessary, because of which said drawbacks are felt to a greater
extent.
[0011] In addition, these drawbacks are considerably multiplied if account is taken of the
fact that the casting operations for the articles are carried out in casting installations
which comprise a large number of complicated moulds, which can exceed fifty in number.
[0012] Because of this, when removing the sanitary appliances from the moulds and when building-up
the moulds again for a subsequent casting stage, a very large employment of labour
is required.
[0013] This fact, together with the aforesaid excessive times necessary for coupling and
uncoupling the known coupling devices, also affects the costs of the finished articles
and the economy of the firm.
[0014] The aforesaid drawbacks are for example felt to a large extent in complex moulds
for sanitary appliances with an integral rim, in which the rim is formed by a multi-piece
collar suspended from the upper mould part.
[0015] The main object of the present invention patent is to provide a casting mould which
remedies the aforesaid drawbacks by means of a simple, functional, rational and highly
reliable constructional design.
[0016] According to the invention, the proposed mould is of the type comprising separate
mould parts which, together with one or more mould pieces, are designed to form a
hollow or solid casting portion in the article cast in the mould, and is characterised
by providing, for each of said separate parts, at least one rotatable member housed
in a convenient seat in said one or more mould pieces, its free end extending until
it practically reaches the zone of contact between the corresponding mould piece and
the relative separate part, where it is provided with an eccentric magnetic block
or metal pad which, when the corresponding rotatable member is in two opposing angular
positions, becomes aligned with and disposed laterally to a metal pad or a magnetic
block embedded in said corresponding separate part, so as to respectively couple together
and uncouple the corresponding mould piece and the relative separate part.
[0017] According to a particular embodiment of the invention, which is especially suitable
for casting sanitary appliances such as bidets, water closets and urinals, the proposed
mould is of the type comprising a lower mould piece, lateral mould pieces arranged
to close together on said lower mould piece to define a casting cavity, an upper mould
piece designed to close said casting cavity, a core branching from the upper mould
piece, and a collar constituted by a set of separate parts and arranged to be disposed
at the base of said core in order to shape the interior of the bowl of the article
to be cast and the lower wall of the corresponding closed integral
rim, and is characterised by providing, for each separate part of the aforesaid collar,
at least one rotatable member housed in a suitable seat of the upper mould piece,
and of which the free end extends until it practically reaches the lower face of said
upper mould piece where it is provided with an eccentric magnetic block which, when
the corresponding rotatable member is in two opposing angular positions, is arranged
to overlie and be disposed to the side of a metal pad embedded in the underlying collar
part, so that this latter becomes retained against the upper mould piece, and released
or uncoupled from it respectively.
[0018] As already stated, it is apparent that the magnetic block and metal pad can be reversed
in position, and disposed on the collar and on the rotatable member respectively.
[0019] In order to provide said support, the rotatable member must be constrained axially
relative to the lower mould piece.
[0020] For this purpose, according to the invention, the rotatable member is of cone-frustum
shape with its minor base facing the internal zone of the mould, and the magnetic
block is embedded in a lateral zone of this latter, of which it occupies preferably
one half.
[0021] The metal pad which is embedded into the corresponding collar part is constructed
of soft iron and is of the same configuration as the magnetic block.
[0022] Finally, the axial constraint of the rotating member can be obtained by other configurations,
such as a cylindrical configuration with differing cross-sections, or a funnel shape.
[0023] The objects and advantages of the invention, together with its characteristics and
constructional merits, will be further clarified and more apparent from the detailed
description given hereinafter with reference to the figures of the accompanying drawings
which illustrate one preferred embodiment thereof by way of non-limiting example only.
Figure 1 is a vertical section through a mould according to the invention, said section
being taken on the vertical plane which separates the lateral mould pieces.
Figure 2 is another vertical section through the invention, the section plane being
orthogonal to the preceding.
Figure 3 is a perspective view of the upper mould piece of a mould according to the
invention, said upper mould piece being shown in an inverted position.
Figure 4 is a perspective view of one of the parts which make up the collar of the
upper mould piece.
Figure 5 is a perspective view of a sanitary appliance obtained with the invention.
Figure 6 is a perspective view of one of the rotatable members with which the invention
is provided.
Figures 7, 8 and 9 are partial sectional views through the mould concerned, which
show the different operating positions assumed by the rotatable members during the
casting stages of a sanitary appliance.
[0024] From said figures, and in particular figures 1 and 2, it can be seen that the mould
according to the invention is composed of a lower mould piece 1, which is of plaster
as are the other mould pieces which constitute said mould, on which two lateral mould
pieces 2 rest and are clamped together. These latter are disposed symmetrically relative
to the lower mould piece 1, and are designed to constitute a suitable casting cavity
inside the mould.
[0025] Furthermore, the pair of lateral mould pieces 2 is designed to externally shape a
sanitary appliance 15 which is cast into the mould. On the pair of lateral mould pieces
2, there rests an upper mould piece 3, with a core 5 projecting from the central zone
of its lower face.
[0026] At the point at which said core 5 joins to the upper mould piece 3, as shown also
in Figure 3, there is provided a perimetral step 11 which, during the casting of the
article 15, receives a collar constructed of plaster as is the core 5, and which is
constituted by a set of separate parts 6, each of which is in the shape of a wedge
or tooth. The mould shown also comprises a rear mould piece 4 which, in combination
with the pair of lateral mould pieces 2, is designed to shape the wall discharge for
the sanitary appliance 15.
[0027] The core 5 and collar 6 are obviously provided for shaping the interior of the bowl
of the sanitary appliance 15 and the lower wall of the closed integral rim thereof.
Although the accompanying figures show a water closet with wall discharge, it must
be stated at this point that the invention is in no way limited to a particular type
or form of article to be cast in the mould, as it is equally suitable for casting
water closets with floor discharge, and for casting bidets and urinals. Each separate
part of the collar 6 is provided, at that longitudinal edge designed to rest against
the perimetral step 11, with a metal pad 10 constructed of soft iron.
[0028] In alignment with the corresponding metal pad 10 when the upper mould piece 3 is
completely assembled, there is provided a cavity 12 which traverses the entire thickness
of the upper mould piece 3 to at least partly emerge above the perimetral step 11.
A rotatable member 7 is intended for insertion into said cone-frustum cavity 12, and
is also of cone-frustum shape, i.e. is configured as a plug, in order to prevent it
moving axially inside the corresponding cavity 12 when the casting mould is completely
assembled.
[0029] As is apparent from the accompanying figures, each rotatable member 7 has its minor
base facing the internal zone of the casting mould, where it is provided with an eccentric
magnetic block 9 which occupies substantially one half of said minor base. This block
is embedded in the material which constitutes the rotatable member 7, and which can
be plaster, a synthetic material or any other convenient material.
[0030] An operating handle 8 projects from the central zone of the major or outer base of
the rotatable member 7.
[0031] The dimensions of the rotatable member 7 are obviously the same as those of the corresponding
cavity 12, so that when said rotatable member 7 is inserted into said cavity 12, the
minor base of the rotatable member 7 becomes disposed substantially coplanar with
the support zone for the perimetral step 11 of the upper mould piece 3.
[0032] When a casting operation is to be carried out, the mould pieces which constitute
the casting mould are assembled in the usual manner, and the separate parts 6 which
constitute the collar of the core 5 are retained against the upper mould piece 3 by
the rotatable members 7 which are rotated in the operational position shown in Figures
1, 2 and 7.
[0033] With this configuration, the magnetic block 9 of each rotatable member 7 lies directly
above the metal pad 10 of the corresponding separate part of the collar 6, so that
it keeps this separate part in its correct operational position.
[0034] With the mould assembled in this manner, the mould is filled with the ceramic material
of slip form, which is subjected to a certain hydrostatic head. After this, a certain
predetermined casting period is allowed to pass, and then the excess slip is drained
from the mould.
[0035] During said casting period, the walls of the sanitary appliance 15 become formed
inside the mould, and at the same time an integral rim of closed type is also defined.
[0036] This is shown in Figure 8, and the rotatable members 7 always maintain the same operating
position described heretofore.
[0037] After said draining stage, the mould is opened, and the article is extracted for
conveying to the next stages of the production cycle.
[0038] The configuration of the parts proposed by the invention offers great advantages
over conventional systems, even during mould opening.
[0039] In this respect, it is known that during mould stripping, all the separate mould
parts fixed to the upper mould piece by means of screws, springs and cross-bars have
to be replaced in position, with serious loss of time and risk of damage.
[0040] This is due to the fact that in order for them to be returned to their position under
the upper mould piece, this latter has to be accessible from above in order to operate
the relative coupling means, and as the upper mould piece is raised this is not possible.
[0041] In contrast, according to the invention, mould stripping is carried out as follows:
The opening of the mould firstly requires extracting the upper mould piece 3, together
with which the core 5 becomes extracted. Before raising said upper mould piece 3,
all the rotatable members 7 are rotated into the position of "disengagement" between
the magnetic blocks 9 and metal pads 10.
The upper mould piece 3 with the core 5 is then raised by means of suitable devices
from which it is suspended, through a small distance for example 1-2 cm, in order
to provide a modest spacing between the blocks 9 and pads 10.
[0042] After this the members 7 are again rotated into their position of "engagement", and
the mould pieces 3 and 5 are then completely extracted.
[0043] Because of the aforesaid spacing, there is obviously no locking action between the
blocks 9 and pads 10.
[0044] At this point, the separate pieces of the collar 6 are removed, and these are then
returned to their position under the raised upper mould pieces 3-5. This is made possible
because the members 7 are rotated into their position of "engagement", and avoids
having to temporarily replace the collar parts, with amongst other things the risk
of damaging them.
[0045] It should be noted that in order to carry out said extraction, each separate part
of the collar 6 has to be pulled downwards and towards the inside of the bowl of the
appliance 15.
[0046] When all the separate parts of the collar 6 have been removed and reassembled with
the upper mould piece, the entire upper part of the mould 3-5-6 is already recomposed
and ready for the next casting.
[0047] As soon as the collar 6 has been completely removed, the rear mould piece 4 is extracted
and the lateral mould pieces of the mould 2 are opened. Finally, the sanitary appliance
15 is removed from the lower mould piece 1, and the mould is ready for a new casting
stage.
[0048] Although not stated heretofore, it is apparent that the upper or outer base of each
rotatable member 7 is provided with a suitable index mark which enables the position
occupied by the corresponding underlying magnetic block 9 to be determined.
[0049] Although the magnetic locking heretofore described is particularly suitable for moulds
for casting sanitary appliances with a closed integral rim, such as water closets,
bidets and urinals, it can be advantageously used in all cases in which a mould for
casting a ceramic material of slip form is required to constitute inside the cast
article a hollow or solid casting region, the constituent walls of which are defined
by separate parts, as is the case of the collar 6 and the upper mould piece 3 in the
example shown.
[0050] The invention is not limited to the single embodiment heretofore described, and modifications
and improvements can be made thereto without leaving the scope of the inventive idea.
Thus for example, the rotatable members 7 do not necessarily have to be of cone-frustum
shape, but can assume any shape which prevents them from moving axially inside the
corresponding cavity 12.
[0051] In this respect, alternatively, according to the invention each rotatable member
7 can be in the form of a cylinder of two different cross-sections, of which the smaller
cross-section is that provided for the magnetic block 9.
[0052] In this case, the cavity 12 will obviously have a conjugate cylindrical configuration.
In addition, the rotatable members and corresponding cavities can be of funnel configuration.
[0053] Finally, it will be apparent that for each separate part of the collar 6, more than
one magnetic block of the type represented and described heretofore can be provided.
1. A mould for casting sanitary appliances with internal projecting parts, such as
a closed integral rim or an anti- splash edge, as heretofore described, of the type
comprising separate mould parts which, together with one or more mould pieces, are
designed to constitute a hollow or solid casting portion in the article cast in the
mould, characterised by providing, for each of said separate parts, at least one rotatable
member housed in a convenient seat in said one or more mould pieces, its free end
extending until it practically reaches the zone of contact between the corresponding
mould piece and the relative separate part, where it is provided with one of-the two
parts of a magnetic locking system, this part being eccentric and, when the corresponding
rotatable member is in two opposing angular positions, becoming aligned with and disposed
laterally to the other part of the magnetic locking system, this latter part being
embedded in said corresponding separate part, so as to respectively couple together
and uncouple from each other the corresponding mould piece and the relative separate
part.
2. A mould as claimed in claim 1, characterised in that one of the two parts of the
magnetic locking system is constituted by a magnetic block, whereas the other part
is constituted by a metal pad.
3. A mould for casting sanitary appliances with solid or hollow internal projecting
parts, especially suitable for bidets, water closets or urinals, as heretofore described,
of the type comprising a lower mould piece arranged to be rested on a convenient support,
at least two lateral mould pieces arranged to be assembled on said lower mould piece
to define a casting cavity, an upper mould piece designed to close said casting cavity,
a core branching from the lower face of the upper mould piece, and a collar constituted
by a set of separate parts and arranged to be disposed at the base of said core in
order to shape the interior of the bowl of the article to be cast and the lower face
of the corresponding projecting internal part, characterised by providing, for each
separate part of the aforesaid collar, at least one rotatable member housed in a suitable
seat of the upper mould piece, relative to which it is locked axially, and of which
the free end extends until it practically reaches the lower face of said upper mould
piece where it is provided with an eccentric magnetic block which, when the corresponding
rotatable member is in two opposing angular positions, is arranged to overlie and
be disposed to the side of a metal pad embedded in the underlying separate collar
part, so that this latter becomes retained against the upper mould piece by the rotatable
member, and uncoupled from said upper mould piece respectively.
4. A mould as claimed in claims 1, 2 and 3, characterised in that said at least one
rotatable member is composed of a cone-frustum body of suitable material with its
minor base facing the central zone of the mould, its opposing or outer end being provided
with an operating handle; said magnetic block or metal pad being embedded in a lateral
zone of the minor base of said cone-frustum body, of which the containing cavity has
a form conjugate thereto.
5. A mould as claimed in claims 1 and 3, characterised in that said at least one rotatable
member is composed of a cylindrical body with at least two different cross-sections,
the portion of smaller cross-section facing the central zone of the mould whereas
that of greater cross-section faces the outside, where it is provided with an operating
handle.
6. A mould as claimed in claims 1 and 3, characterised in that said at least one rotatable
member and cavity for this latter are in the shape of a funnel.
7. A mould as claimed in claims 1, 2 and 3, characterised in that said metal pad or
magnetic block for said at least one rotatable member is substantially configured
as the corresponding magnetic block or metal pad this latter being constructed of
mild steel.