Plastic and nonmetallic article shaping or treating: processes – With measuring – testing – or inspecting – Positioning of a mold part to form a cavity or controlling...
Reexamination Certificate
1999-03-02
2001-09-04
Vargot, Mathieu D. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
With measuring, testing, or inspecting
Positioning of a mold part to form a cavity or controlling...
C264S086000, C264S219000, C264S314000, C264S333000, C425S084000, C425S149000, C425S175000, C425S417000
Reexamination Certificate
active
06284172
ABSTRACT:
The present invention relates to a method and apparatus for making long concrete poles, particularly for use as power poles.
In British Patent Specification No. 2137924 (instant strip) by the present inventor there is disclosed a process and apparatus for forming an elongate concrete moulded article from high slump concrete wherein surplus liquid is removed through a porous membrane extending around the outer perimeter of the article where the membrane is arranged to provide compression to the concrete within the mould, and thereafter separating the membrane from the surface of the partially dried concrete and removing the article from the mould without significant damage to the cast concrete article. This enables almost immediate reuse of the mould.
A disadvantage of this method is that the external periphery of the concrete article, although visually undamaged, is not smooth. Furthermore, the process disclosed therein cannot be easily utilized by application of a membrane to the internal periphery of the article.
In International Publication No. WO86/07559 (corresponding to U.S. Pat. No. 4,996,013) (Pole Dry) also by the same inventor there is disclosed apparatus and a method of casting annular concrete articles such as poles or pipes. The apparatus and method comprises establishing a suitable mould, defining the desired mould cavity or shape into which wet or uncured concrete is introduced. Thereafter excess water is removed from the concrete by pressing the movable internal liner of the core radially against the concrete in one direction within the mould cavity to pass water therefrom through drainage means associated with the movable internal liner to thereby provide a moulded concrete article having the characteristics of at least a partly cured concrete article whereby the mould and core can be removed from the article for reuse.
Problems have been experienced in the method and apparatus disclosed previously which results from an excess of water in the uppersection of the mould which may lead to improper filling of the mould. This problem appears to be caused by water being segregated from the mix during pumping of concrete into the mould and may occur largely because the composition of the concrete mix is designed to allow water to be readily removed during the moulding procedure described in the above mentioned patents. This excess water must be removed in order to properly fill the mould to produce a satisfactory finished article after removal of water from the mix.
Further problems have been encountered with dean removal of the core due to inadequate clearance between the finished concrete and the movable liner and fitter system against which the concrete is cast.
This latter problem is accentuated in the moulding of lengthy tapered poles such as poles used for power lines, with which the invention is particularly, although not exclusively, concerned.
The inner core incorporates a movable liner comprised of relatively abradant sensitive filter material. Therefore, rubbing or relative movement between the filter material and the concrete should be avoided or at least minimized.
Furthermore it is important that the relative movement of the core and mould and reinforcement cage be minimized during filling of the concrete into the mould space and that the formation of air pockets in the concrete is avoided during the mould filling operation.
It is an objective of the present invention to provide improved moulding methods and apparatus that will minimize some or all of the aforementioned problems associated with production of elongated annular concrete products such as poles. It is a further objective to provide improved parts of moulding apparatus as aforesaid mentioned above.
According to one aspect of the present invention there is provided a method of filling a mould with flowable concrete, the method including positioning a core within at least one outer mould section to form an annular moulding space around the core, capping one upper end region of the annular moulding space in a manner permitting escape of fluids therefrom but retaining solid partides within the annular moulding space, introducing flowable concrete into the annular moulding space from a second end region of the mould until the lowable concrete reaches the upper end of the annular moulding space where fluids escape through the one end region of the annular moulding space and fine cement and sand particles are retained therein. Preferably the method may further include sensing a predetermined pressure rise within the moulding space indicative of solid materials in the flowable concrete reaching the one end region of the moulding space whereupon introduction of flowable concrete to the moulding space is stopped. Conveniently the annular moulding space is disposed in a substantially upright configuration and the predetermined pressure rise is sensed at a position located above halfway up the annular moulding space. More preferably, the pressure rise is sensed at or adjacent the one end region of the moulding space.
In accordance with a further aspect, the present invention also provides a method of moulding an elongated annular concrete product, the method including positioning a core within at least one outer mould section to form an annular moulding space around the core, capping one end region of the annular moulding space in a manner permitting escape of fluids therefrom but retaining solid particles within the annular moulding space, introducing flowable concrete into the annular moulding space from a second end region of the mould until the flowable concrete reaches the one end region of the annular moulding space where fluids escape through the one end region of the annular moulding space and fine cement and sand particles are retained therein, thereafter stopping the flow of concrete to the annular mould space, applying inwardly and outwardly directed radial pressure forces to the concrete located in the annular moulding space while at the same time removing surface fluid drawn to an adjacent surface of the concrete in response to application of the pressure forces; removing the outer mould section or sections and the core from the elongated annular concrete product in the moulding space, at least the core being withdrawn while in a substantially upright configuration. Preferably the method also includes sensing a predetermined pressure rise within the moulding space indicative of solid materials in the flowable concrete reaching the one end region of the moulding space whereupon introduction of flowable concrete to the moulding space is stopped. Conveniently the inwardly and outwardly directed radial pressure forces are applied by each of the core and the or each the outer mould section.
In one preferred embodiment, the radial pressure forces applied by the core and the outer mould sections are removed at the same time in a manner preventing substantial pressure force differentials across the concrete in the mould. In a still further embodiment the core applies pressure forces to the concrete prior to pressure forces being applied by the outer mould sections. In a still further embodiment the outer mould sections apply pressure forces to the concrete prior to the core applying pressure forces to the concrete, the pressure forces applied by the outer mould section being initially removed prior to removal of pressure forces applied by the core.
According to a second aspect of the present invention there is provided apparatus for moulding an elongated annular concrete product, the apparatus including at least two outer mould sections relatively movable to form in a first position a substantially enclosed moulding cavity and in a second position opening the moulding cavity, a core member movable into or out of the moulding cavity and when located in the moulding cavity defining an annular moulding zone between the core member and the outer mould sections, filling means arranged to fill the annular moulding zone with flowable concrete from a first end region of the annular moulding zone, and end
Connolly Bove Lodge & Hutz
Hume Brothers Pty Ltd
Vargot Mathieu D.
LandOfFree
Rapid moulding of long concrete poles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rapid moulding of long concrete poles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rapid moulding of long concrete poles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2525843