The present invention relates to molded articles. More specifically, the present invention relates to a molding station and a method for molding articles.
Concrete articles are typically molded at high speed in molding stations incorporating a filling station, and filling of and molding in the mold are usually done on the same spot.
Recently, filling stations comprising an upper door and a lower door have been developed, which allows an increased surface quality of the upper surface of the molded articles (surface opposite the closed bottom of the mold) by reducing an aspiration effect upon opening of the doors, as well as an increased control of the filling of the molds from the filling hopper.
Ongoing efforts for improvement relate to increase the quality of the lower outer surface of the articles, i. e. molded in the bottom of the mold, since it is a visible part of the articles.
Moreover, recurrent problems of overfilling of the mold are still unresolved.
More specifically, there is provided a molding station, comprising a container of moldable material, having a mouth closable with at least a lower door, and a mold to be filled with the moldable material; at least one of: i) the container and ii) the mold being movable into a filling position in which the container is closed by the lower door, the lower door opening to allow an amount of the moldable material to be released into the mold, wherein the mold is made in a deformable material, an interior volume of the mold being temporarily reduced when releasing the moldable material thereinto.
There is further provided a molding station, comprising a container of moldable material, the container having a lower door closing a mouth thereof, and an upper door located above the lower door and defining a compartment therebetween; and a mold to be filled with the moldable material; the container and the mold being brought into a filling position in which the container is closed by the lower door, the compartment comprises a first amount of material and the upper door is closed; the lower door opening to allow the first amount of the moldable material to be released from the compartment into the mold, the upper door then opening to allow a second amount of the moldable material to be released into the mold; wherein the mold is made in a deformable material, an interior volume of the mold being temporarily reduced when releasing the moldable material thereinto.
There is further provided a molding station comprising a container of a moldable material, the container having a lower door closing a mouth thereof, and an upper door located above the lower door; a feedbox movable between the upper door and the lower door of the feedbox; and a mold to be filled with the moldable material; wherein the container, the feedbox and the mold are brought into a filling position in which the container and the mold are separated by the feedbox, the upper door and the lower door is closed and the feedbox contains a first amount of the moldable material; the lower door then opening to allow the first amount of material to be released from the feedbox into the mold; and the upper door further opening to release a second amount of material into the mold, the lower door and the upper door shutting closed when the mold is filled, the lower door and the feedbox being then withdrawn and the mold and the container returned to a separated position; wherein the mold is made in a deformable material, an interior volume thereof being temporarily reduced when releasing the moldable material thereinto.
There is further provided a method for filling a mold with a moldable material, comprising the acts of bringing a container of moldable material, the container having a mouth closable with a lower door, and a mold to be filled with the moldable material into a filling position in which the container is closed by the lower door; reducing an interior volume of the mold; opening the lower door to allow an amount of the moldable material to be released into the mold; closing back the lower door when the mold is filled; and withdrawing the mold.
There is further provided a mold for molding an article, wherein the mold is made in a deformable material, an interior volume thereof being temporarily reduced when pouring a moldable material thereinto.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.
In the appended drawings:
The present system and method generally allow controlling overfilling of the mold.
In a first embodiment of an aspect of the present invention, as shown in
The mold 22 is typically made in urethane or flexible polyurethane, for easy demolding as well as for surface finish, or neoprene, natural rubber etc, for example.
The mold 22 and the hopper 16 are brought in a filling position, in which the lower door 20 closes the mouth of the hopper 16 and the mold 22 is in position beneath the lower door 20 (
The lower door 20 may be actuated by sets of pneumatics and/or hydraulics as known in the art.
In
As can be seen in the Figures, the mold 22 is provided with a support 28 made in a material allowing compressing the mold 22 as the mold is being filled. As a result, due to a slight buckling of the sidewalls of the mold 22 as seen in
Other ways of reducing the interior volume of the mold 22 prior to releasing the material therein may be contemplated, as will be described hereinbelow, for example in relation to
Alternatively, it may be contemplating having the mold fixed into position and the hopper coming into the filling position with the lower door closed above the mold, and submitting the mold to compression during pouring of the moldable material.
Another way may be to have empty molds being fed in a line under the hopper, with the lower door closed, through a passage putting them in a slight compression, for the pouring of the moldable material.
It is to be noted that upon withdrawal of the mold 22, once filled, from under the hopper 16, a scraping action by the closed lower door 20 on the upper surface of the mold 22 further contributes to avoid overfilling of the mold 22 by removing any material in excess, if any.
In a second embodiment illustrated in
Then, as shown in
Again, the interior volume of the mold 22 may be decreased prior to pouring the material therein, by a pression submitted by a support 28, for example.
Again, it is to be noted that upon withdrawal of the full mold from under the hopper 16 in
Furthermore, in this embodiment, the pouring of the material takes place in several stages, which may be beneficial, especially in the case of deep molds, as people in the art will appreciate.
In a further embodiment described in
Each one of the upper and lower doors 18 and 20 may be actuated by sets of pneumatics and/or hydraulics as known in the art.
The wet moldable material is contained in the hopper 16 when the upper door 18 is in the closing position, and the feedbox 26 may be filled with material upon opening the upper door 18.
Here, prior to releasing a first amount of the moldable material from the feedbox 26, the feedbox 26, containing this first amount of wet moldable material 30, is prepared in position on the upper surface of the lower door 20 in the open position, the upper door 18 being closed, the mold 22, empty, being in a low position (see
Then, the empty mold 22 is moved up towards the mouth of the hopper 16 (see
The new empty mold may be filled along the same acts as described hereinabove.
As may be seen from the Figures, the interior volume of the mold 22 may be reduced prior to filling, by a number of ways, including for example by buckling of the sidewalls of the mold 22 submitting the mold to a compression exerted by the hopper and the feedbox between the doors during pouring of the moldable material as described before, or having empty molds being fed in a line under the hopper and the feedbox through a passage putting them in a slight compression, for the pouring of the moldable material, as mentioned hereinabove.
In still another way, illustrated in
Furthermore, as may be seen in the Figures, the feedbox 26 may be provided with a scraper 32, so that, upon withdrawal of the lower door 20 and the feedbox 26, the scraper 32 removes material in excess 31 at the surface of the filled mold 22 (see
It is found that a multiple-stage filling of a mold as described hereinabove, whereby a first amount of material is released in the mold in a first act, before a second amount of material is then poured in, allows obtaining a lower part of the molded article, corresponding to the first amount of material, devoid of bubbles or asperities.
As people in the art will appreciate, the mold 22 may be further connected to a vibration platform 24 as shown in
In the case of a mold displaceable up to and down from the mouth of the hopper, a lifting member, such as a scissor table 12, for example on a base 14, as shown in
In the embodiments described hereinabove, the mold 22 and the hopper 16 are brought into a filling position by a movement of the mold 22 relative to the hopper 16. Obviously, the mold 22 could be fixed and the hopper 16 displaceable.
Moreover, a circular arrangement may be contemplated, as illustrated in
Using a deformable mold 22, thus allows preventing overfilling of the mold 22, which may be further corrected by using a scraping action as described hereinabove.
Although the present invention has been described hereinabove by way of embodiments thereof, it may be modified, without departing from the nature and teachings of the subject invention as defined in the appended claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA07/02345 | 12/20/2007 | WO | 00 | 6/17/2009 |
Number | Date | Country | |
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60871180 | Dec 2006 | US |