Note: Descriptions are shown in the official language in which they were submitted.
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FILE, ~ THIS f~h~lD~D`
-` ~3~ TRAN SLATION
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"Mold for concrete-block molding machine~"
Description:
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The invention relates to a mold for concre~e-
block molding machines, with a molding frame having at
least one chamber which iB open at the top and bottom and
which is bounded by chamber walls.
A mold of this type i~ known from
EP-A2 0,318,708. In order to carry out the molding
operation, the mold is placed onto a vibrating table and
filled with a relatively dry concrete mixture. A ram
fitting exactly into the chamber then plunges from above
into the chamber, and the load of the ram can likewiee be
provided with a vibrator. After compaction, the molding~,
which remain adhering in the chamber even after the
removal of the vibrating table, are deposited onto a
conveying means or on moldings produced in a preceding
operation, after dry sand has been scattered on as a
separating agent (multi-layer finisher). For this pur-
pose, the molding frame moves upwards, 80 that the r~m,
initially remaining in its position, pre~ses the molding
out of the chamber.
However, there are also concrete moldings which,
a~ a result of their high weight and as a result of
reduced contact with the chamber walls, would fall out of
the chamber while the mold is being raised. One 0xa~ple
of this i~ curbstones which have a rounding and an
oblique face which are shaped by means of a special ram
(blade). The oblique face does not contribute to adhe~ion
in the mold.
Other concrete bodies acquire a special design of
their lower surface by means of a so-called undersleove.
By this is meant a mold part which i~ inserted into the
ampty chamber and which remains on the molding after the
molding operation. Only after the molding has harden~d is
the undersleeve detached from it.
Finally, it i~ necessary to consider the in~tance
where a layer element i~ introduced into the empty
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I chamber and is to be connected permanently to the con-
~ crete body to be produced, in order to form a co~posite
3 body. The connection is obtained by means of a rough or
specially bonding surface of the layer element on the
side facing the concrete and/or by the use of suitable
bonding agents. Examples of layer elements, which, in the
instance of use, lie on the top side or on the visible
side of the compsite body, are ceramic or clay elements,
natural-stone slabs or the like.
The object on which the invention is based is to
design a mold in such a way that even heavy moldings can
bo held in the mold and be raised together with the
latter, and that the mold can automatically receive and
retain insertion parts and layer elements before the
concrete i8 introduced and, even after the molding
operation, can raise and carry the insertion part,
together with the concrete body or the composite body, 80
that the latter can be deposited on a base different from
the production base (vibrating table).
In a mold of the type defined in the introduc-
tion, this object is achieved, according to the i~en-
tion, by means of the characterizing features of Claim 1.
The proposed clamping device increases the transver~e
force exerted on the particular part to be retained and
thereby, within a specific time interval which i8 select-
able, increases the friction on the chamber wall. Thu~,
concrete bodies produced in the empty chamber c~n be
retained. In other cases, it is possible to slip the
molding frame or the molding chambers over the part or
parts to be received and then actuate the clamping
device, 80 that these parts are then retained after the
base has been removed from the mold.
Since molds of this type are used in production
machines working automatically, it is essential that the
clamping device should work automatically. It is there-
fore advantageous to actuate it by means of a pressure
medium, the pressure of which can be controlled.
The particular difficulty in the conctruction of
the clamping device is that molds of this type are
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subjected to extremely harsh vibrating stres~. ~oreover,
the thickne6s of the chamber walls is limited. In ~rinci-
ple, the clamping device can contain flat tapered slide
valves which are movable by means of a working cylinder
and which are themselves connected operatively to a
suitably designed clamping member. The return of the
clamping members into the initial position could be
carried out by means of springs or likewise hydraulical-
ly/pneumatically.
It is proposed, as a particularly simple and
therefore preferred embodiment, that the chamber walls
have on the inside a groove, into which an elastic ho~e
loaded by the pressure medium is inserted. ~he groove
extends preferably horizontally, that is to say parallel
to the lower edge of the chamber wall. When the hoss is
put under pressure, it inflates and endeavors to swell
beyond the groove. At the same time, it presses onto the
part to be retained. A clamping device of this type can
extend from chamber corner to ch~her corner or al~o be
shorter than the respective chamber wall. If the part to
be retained is relatively light, a clamping de~ice on one
chamber wall may already be sufficient. However, clamping
arrangements can also be mounted on two opposite or on
all chamber walls.
For the last-mentioned instance, it is proposed
that the ho~e or a plurality of hose portions be part of
a closed ring conduit which extends over the entire
chamber circumference and of which the connecting conduit
coming from a pressure-control device is brought through
a chamber wall. It is possible to use angular pipe~ at
the corners and a pipe T-piece made of metal for the
connecting conduit and to connect these pipes to etraight
flexible ho~e pieces. However, a ready-vulcanized annular
hose can also be used. The advantage of this is that, in
addition to its clamping effect, the annular hose also
perform~ a sealing function and, all-round, prevents the
penetration of concrete slurry into the gap between the
chamber wall and the part to be retained.
Various alternatives are proposed for the
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cross-section of the hose and of the groove. In order to
assist the retraction of the hose in the pres~ureless
state, it is expedient if the grooYe i8 narrowed toward~
groove orifices by means of bead-like projection~ of the
~ 5 groove side walls. However, the groove side walls can
3 also intentionally be kept plane, 80 that the ho~e,
likewise provided with plane flanks, can slide between
them. In order to achieve a high bearing force, the hose
can have, between the flanks, a plane pre~ure face.
However, this can also be provided with sealing lips or
flutes. In a development of thiR idea, it can be
expedient to depart completely from the cros6-section of
a hose with an essentially uniform wall thickness and to
form onto it a rectangular gripping and sealing strip of
solid cross-section. It iB proposed, furthermore, that
the hose be retained at the rear, that is to say on the
inside of the groove, 90 that it retracts completely into
the groove a~ a result of its elasticity or by being
sub~ected to a vacuum. This fixing of the hose in the
groove can also be brought about by an appropriate design
of the cross-section, for example by forming onto the
hose at the rear a bead which snaps into a corre~pond-
ingly de~igned receiving groove.
In order to protect the hose against abrasion and
damage, it is proposed that a strip covering the hose be
inserted as a clamping member into the groove. This strip
can consist of a suitable plastic, but also of metal, and
be connected to the hose by means of flat clip8 partially
surrounding the hose or in another way.
Instead of a hose in the narrower sense, a wider
expansion element, that is to say a cushion or a concert-
ina loaded by the pressure medium, can also be provided,
in which case such an expansion element could actuate a
plate-like clamping member.
When layer elements consisting of a relativQly
brittle, that is to say impact-sensitive, or soft materi-
al are used, there is the risk that the edges of the
layer element will be damaged by impact against the
chamber wall during vibration. In order to counteract
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this risk, it is proposed that a lower region of the
inner face of the chamber wall which contains the clamp-
ing device be set back relative to the remaining inner
face, for example by a few millimeters. The height of the
Ret-back region should exceed a little the height of the
layer element on its outer circumference.
In order to prevent the rebound contact men-
tioned, it is expedient if the chamber wall posse~ses, if
appropriate in addition to the set-back of the inner
face, above the clamping device a horizontally extending
groove, into which is inserted an elastic impact-protec-
t~on strip which is softer than the chamber wall, but
nevertheless harder than the inflated clamping hose.
Preferably, the impact-protection strip, which can have
a rectangular or trapezoidal cross-section, is arra~ged
directly below the shoulder which forms the transition
between the inner face and the ~et-back inner-face
portion of the chamber wall.
Exemplary embodiments of the invention are
explained below by mean~ of the drawing.
In particular, in this:
Figure 1 shows a diagrammatic representation
in vertical section of a mold for a
concrete curbstone,
Figure 2 shows, in a corresponding repre~en-
tation, a mold for a light well with
a frame-like undersleeve of angular
cross-section,
Figure 3 shows, in a corre~ponding represen-
tation, a mold for a concrete gutter
with an undersleeve,
Figure 4 shows, in a corresponding repre~en-
tation, a mold for a gutter stone in
the form of a composite body con-
sisting of a gutter made of clay and
of a lower concrete body,
Figure 5 shows a vertical section of ~he
lower part of a chamber wall and of
a composite slab produeed in thi~
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chamber, in approximately natural
size,
Figures 6-9 ~how different versions of ho~e cro-
ss-section~, likewise on an approxi-
mately natural scale,
Figure 10 shows a multi-sectional top view of
an annular hose, such as i~ used in
the molding chamber according to
Figure 5, on a smaller ~cale, and
Figure 11 shows a vertical section of the
lower part of another chamber wall,
the hose not being shown for the
sake of clarity.
The diagrammatic repre~entations of Figures 1
to 4 are intended to give examples of tha use of the
invention. Figure 1 show~ a box mold with two mutually
opposite longitudinal walls 1 and 2, which servee for the
production of a curbstone 3 made of concrete. To simplify
the diagram, the rear end wall is not ~hown. A ram 4, the
so-called blade, indicated by dot-and-dashed lines
engag~s into the mold from above. The obligue face 5
typical of these concrete bodies i8 obtained therQby.
Without special measures, the freshly compac~ed molding
would 81ip out of the mold while the latter was baing
rai~ed. Consequently, there is formed on the inner faces
of the chamber, in the lower region, a groove whi~h
extonds all-round and which contains an elastic ho~e 6
connected to a pressure-medium source 9 via a connecting
conduit 7 and a pressure-control device 8. Thi~ is shown
in Figure 10. This hose is a frame-like hose having a
connection piece which i8 made in one piece. When this
hoso, which encircles the curbstone 3, is put under
pressure, it prevents the concrete body from falling out
of the mold when the latter is lifted off fro~ the
vibrating table.
The mold according to Figure 2 serves for the
production of a U-shaped light well 10 for ~ellar win-
dows. The sectional plane extends transversely to the ~-
logs. The sectional diagram shows the two outer
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transverse walls 11 and 12 and the two inner tran~v~r~e
walls 11' and 12' which form the legs of the light
~, well 10. In order to provide a clearance at the inner
edge of the light well 10 for the insertion of a grating,
a U-shaped undersleeve 13 is inserted into the mold. It
ha~ an L-shaped cross-~ection, the vertical leg forming
the ~aid clearance. Located opposite this ~ertical leg,
ln the chamber walls 11' and 12', are groove~ having
inserted hoses 6' which could be connected by means of a
groove and a hose piece in the longitudinal wall connect-
ing these two transverse walls.
At the start of the molding operation, this mold
iB lowered over the undersleeve brought up by mea~s of a
conveying base and located exactly in posit~on. The
hose 6 i~ then put under pressure and the undersleeve is
consequently clamped in the mold. The conveying ba~e for
the undersleeve can then be removed and the mold lowerad
onto the vibrating table. Even after the concrete has
been introduced and compacted, the mold, together with
the concrete and the undersleeve, can be deposited again
on another conveying base. For removal from the mold, the
internal pressure of the hose 6' i8 relaxed.
In the example according to Figure 3, a molding
box, similar to that of Figure 1, with longitudinal
walls 1 and 2 is provided. A concrete gutter 14 i~
produced in this. For forming the shape of the gutter,
there is an undersleeve 15, on the top side of which the
gutter shape is formed as a positive counterpart. ~ere
too, the mold initially receives the undersleeve 15 and
retains it by means of the pressurized ho~e. After the
concrete has been introduced and compacted, the concrete
and undersleeve are deposited on any base and remov~d
from the mold. After the setting of the concrete, the
undersleeve 15 is detached from the finished concrete
gutter 14. The number of undersleeves present in a
production plant usually corresponds to a daily produc-
tion of corresponding concrete moldings.
In the example according to Figure 4, a mold
approximately identical to that of the preceding example
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serves for producing a water gutter as a composit~ body
consisting of a lower concrete part 16 and of a gutter
part 17 made of clay. Here, the gutter part 17 is re-
eeived by the initially empty mold in the same way as the
undersleeve 15 according to Figure 3. The e~Qential
difference from this preceding example i~ that, as a
result of the stepped dovetail shape of its top side; the
gutter part 17 bonds firmly with the eonerete body. The
co~posite body thus produced has a high stability ac a
recult of its lower eoncrete part 16 and, on the s~d2 at
the top in the installed state, offers a gutter made of
the eeramie material desired here.
Figure 5 show~ as a further example, in a repres-
entation true to seale, the relevant part of a mold for
the production of a composite slab whieh eonsist~ of a
natural-stone slab 18 and of a eonerete layer l9o The
natural-stone slab 18, on its bonding faee at the top
aeeording to Figure 5, is naturally rough and, to in-
ereace the bonding strength, is provided where possible
with elearanees and is additionally coated with a bonding
agent. Such compo~ite slab~ serve for the production of
partieularly attractive large-area ground eoverings over
whieh heavy vehicles can travel.
The molding chamber, in the upper region of its
ehamber wall 20 in which the ram runs and eonerete is
introdueed, has a clear width whieh eorresponds exaatly
to the width of the natural-stone slab 18. Starting a
little above the natural-stone slab 18, the molding
ehamber widens via an oblique shoulder 21 and forms, with
the side faces of the natural-stone slab 18, a gap 22 of
a width of approximately 2.5 mm. The set-back plane
surfaee portion 23 at the lower end of the ehamber
wall 20 merges at the bottom into the oblique faee 24
whieh, ehould the molding frame and the natural-~tone
clab not be located in exaetly eorresponding po~ition~,
i~ intended to prevent them from being damaged during the
lowering of the molding frame and to bring about a
eorrecponding centering.
In the region of the set-baek faee portion 23,
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the chamber wall 20 has an e sentially rectangular
groove 25, the upper side wall of which is approximately
at the same height as the upper face of the natural-stone
slab 18. The groove 25 i8 narrowed towards the orifics,
that is to say towards the natural-stone slab 18, by
means of two bead-like curved projections 26 on the
groove side walls. Finally, the natural-stone slab 18 has
a chamfer 27 at its upper edges. The natural-stone
slab 18 is thus at a distance from the chamber wall 20 on
all sides, 80 that it cannot be damaged during vibration.
However, the width of the gap 22 uniform all-round is
also important because the side faces of the supporting
conGrete layer 19 would have to form a common plane with
the ~ide faces of the natural-stone slab 18. This too is
brought about by the hose 6 which can be loaded by msans
of air pressure. It seals off the gap 22 all-round and
presses 80 firmly onto the side faces of the natural-
stone slab 18 that the latter does not slip out downwards
when the molding frame is lifted out, specifically not
even when concrete has already been introduaed into the
molding chamber and compacted. In conclusion, during
r~moval from the mold, the ho~e 6 ensures that the
concrete ~lurry, which has penetrated into the receea
between the shoulder 21 and the hose 6 during vibration,
is pu~hed upwards and distributed 80 that the finished
composite slab appears with smooth side walls. For thi~
purpose, the air pressure in the hose 6 i8 reduced to
such an extent that the hose can perform this function of
a wiping lip. The result of the complete cancellation of
the air pressure is that the hose 6 retracts completely
into the groove 25 as a consequence of the beads 26.
Figure 7 shows another hose cross-section which
i~ intended for a groove with plane side walls and whick
correspondingly possesses plane flanks 28 and a plane
pressure face 29. Wedge-shaped sealing lip~ 30 are formed
on the latter in the manner of a pressure-sensitive
sucker.
The hose profile according to Figure 8 differs
from the preceding one in a smaller oval cavity and in a
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virtually rectangular solid profile portion which can
also be designated as a formed-on gripping and sealing
strip 31.
Figure 9, in addition to a further hose profile,
also ~hows the associated groove shape. ~ssential here is
a rear T-shaped profile extension 32 which engages into
a corresponding shaped-out portion of the groo~e bottom
and which thus retains the otherwise round hose in the
groove which widens towards the groove orifice. When the
hose is put under pressure, it fills the groove and
reaches beyond the latter over a relatively large width,
this being indicated by dot-and-dashed lines.
Figure 11 shows the design of a further chamber
wall 32 in the relevant region. The hose groove 33 shown
here has a slightly different cross sectional shape from
that in Figure 5. It i8 rounded on the groove bottom.
Above the hose groove 33 is provided a further rectangu-
lar groove which is parallel to the latter and into which
is inserted an impact-protection strip 34 made of rubber
or a suitable plastic. This groove is located at the
point of transition between the upper portion and the
lower set-back portion of the wall inner face. The
natural-stone slab 35 used here has no chamfer at the
transitional edge between its top face and its side face.
The impact-protection strip 34 sarves for protecting this
edge during vibration and for the additional sealing off
of the gap designated by 22 in Figure 5.
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. 1 1 --
1 Longitudinal wall
2 Longitudinal wall
3 Curbstone
4 Ram
Oblique face
6 Hose
6' Hose
7 Connecting conduit
8 Pressure-control device
9 Pressure-medium source
Light well
11 Transverse wall (outer)
11' Transverse wall (inner)
12 Transverse wall (outer) ~-
12' Transverse wall ~inner)
13 Undersleeve
14 Concrete gutter
Under61eeve
16 Lower concrete part
17 Gutter part
18 Natural-stone slab
19 Concrete layer
Chamber wall
21 Shoulder
22 Gap
23 Face portion
24 Oblique face
Groove
26 Projections
27 Chamfer
28 Flank
29 Pressure face
Sealing lip
31 Gripping and sealing strip
32 Cha~her wall
33 Hose groove
34 Impact-protection strip
Natural-stone slab
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