WO2009149709A1

WO2009149709A1 - A negative disposable mould piece for the casting of well bottoms and a method of making a disposable mould piece as well as a method of casting a well bottom with the disposable mould piece

Info

Publication number: WO2009149709A1
Application number: PCT/DK2009/000118
Authority: WO
Inventors: Søren Duelund SØRENSEN
Original assignee: Grindsted Betonvarefabrik A/S
Priority date: 2008-06-09
Filing date: 2009-05-27
Publication date: 2009-12-17
Also published as: DK176847B1

Abstract

The invention relates to a negative disposable mould piece (1) for the casting of well bottoms (12) of concrete in cooperation with an outer form and one or more core mould pieces (9), said well bottoms comprising bottom channels (5), banquettes (6) and two or more connection openings (13,14) for pipes. The invention moreover relates to a method of making the disposable mould piece (1), as well as a method of making an individual well bottom (12) of concrete in a mould comprising a disposable mould piece (1), a bottom frame (8), an outer form (7), a profile ring (10), a core mould piece (9) and a top plate (11). The invention provides a rapid and efficient method of making individual well bottoms. The production time is reduced considerably, and the method is without the environmental drawbacks which characterize the production of hand-made well bottoms.

Description

A NEGATIVE DISPOSABLE MOULD PIECE FOR THE CASTING OF WELL BOTTOMS AND A METHOD OF MAKING A DISPOSABLE MOULD PIECE AS WELL AS A METHOD OF CASTING A WELL BOTTOM WITH THE DISPOSABLE MOULD PIECE

The invention relates to a negative disposable mould piece for the casting of well bottoms of concrete in cooperation with an outer form and one or more core mould pieces, said well bottoms comprising bottom channels, banquettes and two or more connection openings for pipes.

Moreover, the invention relates to a method of making the disposable mould piece as well as a method of casting an individual well bottom of concrete in a mould comprising a disposable mould piece, a bottom frame, an outer form, a profile ring, a core mould piece and a top plate.

The prior art

Sewer systems are composed of pipelines and wells, which have been de- veloped for the discharge of sewage, wastewater and rainwater from roads, open spaces and squares, fields, dwellings and industrial buildings. The wells serve to gather or change the direction of the pipelines, just as they provide the possibility of inspecting the clearance in a pipeline and of implementing cleaning of the pipeline system if this should be required.

Wells are made in many sizes and consist of a well bottom, one or more well rings, a cone and a cover. The size of well rings, cones and covers are standardized, and, therefore, these components are typically stock goods. The well bottom, on the other hand, must be made individually for each well. There are two types of well bottoms for a sand trap well and a banquette well, respectively.

The bottom for a sand trap well is made of a well ring in which a plane bot- torn is cast. The pipe connections are typically arranged half a metre above the bottom, thereby allowing precipitation of sand and other particles. The positions of the pipe connections in the well ring are determined by the courses and directions of the pipelines.

The bottom for a banquette well is made of a well ring in which a bottom is cast. The bottom is provided with a bottom channel between the connection openings to ensure the hydraulic flow through the well. The bottom channel may be branched. Banquettes are cast between the bottom channels and the walls of the well, said banquettes having an inclination which directs particles, sludge and other aqueous waste down toward the bottom channels, thereby avoiding accumulations of waste in the well bottom, thus preventing rats from establishing nets.

The well bottom for a banquette well is made individually for a specific task. The total working time amounts to between 4 and 6 hours distributed over 3 days. The process is slow, which is caused by the individual construction. A well ring is taken from the store, holes are drilled for pipe connections, and then the bottom is cast and left to cure for at least 12 hours. Casting of bottom channels and banquettes is then carried out as manual work. Since, typically, the well rings are from 50 to 100 cm tall, this gives a very inexpedient working posture. The bottom channel and the banquettes are constructed in coarse concrete, which is subsequently given a finishing treatment. This work thus takes place in a forwardly bent posture down in the well bottom and constitutes a great strain on the person performing the work. Attempts have been made at remedying this disadvantageous production method by standardizing the well bottoms, so that they may be made in moulds having different mould cores and are stocked in a plurality of variants. However, it has been found that the projecting enterprises frequently require solutions which cannot be realized by a standardized product. Levels as well as angles slip during the projecting process and subsequently during the assembly, the result of this being that an individual well has to be made.

Frequently, the order for the supply of an individual well is placed so late that the three days which have to be spent on the production, involve delays in the construction work.

The object of the invention

It is the object of the invention to remedy these many drawbacks, and this is achieved by introducing a disposable mould piece, which is made of an undivided, solid and mouldable material, and which additionally comprises a first boundary made as a negative cast of a complete well bottom having bottom channels and banquettes, and a second boundary facing in the opposite direction in the form of an essentially circular, plane face, as well as a third boundary which is essentially perpendicular to the plane face and extends between the first and second boundaries and has a course which follows the periphery of the plane face.

When, as stated in claim 2, a mouldable material is used, comprising polystyrene foam or another foamed plastic material, which is likewise workable, and which has strength properties like polystyrene foam, an inexpen- sive, durable and readily workable material for the making of a disposable mould piece is achieved. Claim 3 discloses a method of making a disposable mould piece, where the boundaries of the disposable mould piece are converted into program specifications for a programmable machine, and these program specifica- tions are entered into the programmable machine, following which a single block of solid plastics is worked into a disposable mould piece on the machine according to the specifications entered. This method provides a rapid and efficient way of making a disposable mould piece.

When, as stated in claim 4, the program specifications are produced by means of CAD and CAM systems, a rapid and efficient way of producing program specifications for a programmable machine is provided.

When, as stated in claims 5 and 6, a method for the individual casting of a well bottom is disclosed, wherein it is described how the disposable mould piece is arranged in a mould, which is then filled with concrete and is left to cure, it is advantageously ensured that a well bottom may be made in one working operation, and that the harmful working postures are avoided.

The drawing

Preferred working examples will be described more fully below with reference to the drawing, in which

Fig. 1 shows a sectional view of a negative disposable mould piece according to the invention,

Fig. 2 shows a sectional view of a mould for the casting of a well bottom prior to the mounting of a disposable mould piece, Fig. 3 shows a sectional view of an assembled mould having a negative mould piece,

Fig. 4 shows a sectional view of a mould with poured concrete, and

Fig. 5 shows a sectional view of a cast well bottom.

Description of the working examples

Working examples shown in figs. 1 - 5 will be described below.

Fig. 1 shows a negative disposable mould piece 1. The mould piece is made of a mouldable material comprising polystyrene foam or other plas- tics, which may likewise be foamed and worked and have strength properties like polystyrene foam.

The mould piece 1 is configured so as to cover the entire well bottom and comprises three boundaries. The first boundary 2 is configured as a nega- tive cast of a complete well bottom with a bottom channel 5 and banquettes 6. The second boundary 3 is configured as a circular, plane face 3a, whose periphery adjoins the third boundary 4, which is essentially perpendicular to the plane face 3a and establishes a connection between the first boundary 2 and the second boundary 3, and has a course which matches the di- ameter of a core mould piece 9 (see fig. 2).

The mould piece 1 may be constructed with the bottom channel 5 in various variants. It may be constructed with a rectilinear course, as a course with a bend or as a course with branches, and with different levels for the inlet and outlet openings 13, 14. The banquettes 6, which constitute the part of the well bottom which is disposed between the bottom channels 5 and the inner side of the well, are configured with a fall toward the bottom channels, so that particles, sludge and other aqueous waste cannot accumulate, and so that rats cannot es- tablish nests.

The mould piece 1 is made of a single solid block of plasties on a programmable machine according to specifications entered. The programmable machine is typically a robot or a CNC machine having milling tools mounted thereon, but also other types of tools suitable for the working of foamed plastics may be used on the programmable machine.

The information on the size of the well bottom, the course of bottom channels, the inclination of the banquettes, the size of the openings of the con- nections, their number, the angle between the openings and their levels forms the basis for the preparation of 3D drawings on a CAD system, said drawings being applied for the creation of program specifications in a CAM system which are to be entered into the programmable working machine.

Fig. 2 shows a sectional view of a mould for the casting of a well bottom of concrete before the disposable mould piece 1 is mounted.

The mould comprises an outer form 7, which consists of two halves of steel which may be clamped together to form a cylindrical chamber. The outer form is provided with collars at the top and the bottom for stiffening the mould and for clamping on a bottom frame 8.

The bottom frame 8 is cross-shaped and has a size so as to be capable of receiving the outer form with collar for clamping. A mould core 9 of steel is placed on the bottom frame internally of the outer form. The mould core is clamped to the bottom frame 8. The height and the diameter of the mould core may be adjusted to the task by adjustment on a clamping device. The thickness of the sides of the well bottom is determined by the difference between the internal diameter of the outer form and the external diameter of the mould core. The thickness of the bottom may be adjusted inter alia by changing the height of the mould core 9.

The uppermost boundary of the mould core is formed by a top plate 11 , which is clamped on the mould core.

A profile ring 10 is arranged externally on the mould core. It is clamped to the bottom frame 8. The profile ring forms a depression in the finished object and extends all the way round in the centre of the edge of the well ring. A sealing element may be arranged in the depression. The depression also serves as a guide for a subsequent well ring.

Fig. 3 shows a sectional view of an assembled mould with a disposable mould piece 1. The disposable mould piece 1 is secured to the top plate 11 , such that the vertical boundary 4 of the mould piece is flush with the external boundary of the mould core. The mould piece is secured to the top plate by an adhesive.

The mould piece is lubricated with a slip agent, which ensures that the mould piece may be separated from the poured, cured concrete and leaves a smooth surface in the bottom channels and on the banquettes.

Fig. 4 shows a sectional view of a mould with poured concrete. The concrete is of a vibration-free type, such as e.g. SCC concrete. After curing, the object may be removed from the mould. The curing times may vary according to the type of the concrete, but is typically between 8 and 14 hours. Fig. 5 shows a sectional view of a well bottom 12, which is cast in one working operation, so that the operators are not subjected to inexpedient working postures.

The well bottom 12 is made individually to order. The information of the order forms the basis for the selection of outer form 7, core mould piece 9 and profile ring 10 as well as for the preparation of 3D drawings of the boundaries for a negative disposable mould piece of the well bottom, said drawings being converted into program specifications which may be entered into a programmable machine.

A single solid block of plastics is then worked on the programmable machine into a disposable mould piece according to the specifications entered.

An outer form 7 is arranged on a bottom frame 8, and a core mould piece 9 and a profile ring 10 are arranged at the bottom of the outer form 7 on top of the bottom frame 8.

The disposable mould piece 1 is then secured to a top plate 11 , which is arranged on top of the core mould piece 9 and is secured to it. The mould piece 1 is then lubricated with a slip agent.

Concrete is poured into the assembled form up to the upper edge of the outer form, and the poured concrete is left to cure and is stripped when curing has been completed.

The well bottom may also be made in a mould without a mould core, as the disposable mould piece may also be dimensioned to fill the part of the mould which the mould core normally occupies.

Claims

PATENT CLAIMS

1. A negative disposable mould piece for the casting of well bottoms of concrete in cooperation with an outer form and one or more core mould pieces, said well bottoms comprising bottom channels, banquettes and two or more connection openings, cha ra cte rized in that the disposable mould piece (1 ) is made of an undivided, solid and mouldable material and comprises a first boundary (2), which is configured as a negative cast of a complete well bottom (12) hav- ing bottom channels (5) and banquettes (6), and a second boundary (3) facing in the opposite direction and configured as an essentially circular, plane face (3a), as well as a third boundary (4) which is essentially perpendicular to the plane face (3a) and extends between the first and second boundaries and has a course which follows the periphery of the plane face.

2. A disposable mould piece according to claim 1, ch a racterized in that the workable material comprises the plastic material polystyrene foam or another plastic material which may be foamed and worked and has strength properties like polystyrene foam.

3. A method of making a disposable mould piece according to any one of the preceding claims, characterized in that the boundaries (2, 3, 4) of the disposable mould piece (1) are converted into program specifications for a programmable machine, that the program specifications are entered into a programmable machine for the working of the disposable mould piece (1 ), and that a single solid block of plastics is worked into a disposable mould piece on the programmable machine according to the specifications entered.

4. A method of making a disposable mould piece according to claim 3, characterized in that the boundaries (2, 3, 4) of the mould piece (1) are defined by means of a CAD system, in which 3D drawings of the mould piece are prepared on the basis of the information on the size of the well bottom (12), the course of the bottom channels (5), the inclination of the banquettes (6) as well as the size, number, position and levels of the connection openings (13, 14), and that the specifications from the CAD system are converted into program specifications in a CAM system so as to be readable by a programmable machine.

5. A method of making an individual well bottom (12) of concrete in a mould comprising a disposable mould piece (1) according to any one of the preceding claims, a bottom frame (8), an outer form (7), a core mould piece (9), a profile ring (10) and a top plate (11 ), c h a r a c t e r i z e d in that an outer form (7) is arranged on a bottom frame (8), and that a core mould piece (9) and a profile ring (10) are arranged at the bottom of the outer form on top of the bottom frame, that the disposable mould piece (1 ) is then secured to a top plate (11 ), which is arranged on top of the core mould piece (9) and is secured to it, that the disposable mould piece (1 ) is lubricated with a slip agent, that concrete is poured into the mould to the upper edge of the outer form, and that the well bottom (12) is removed from the mould after the curing has been completed.

6. A method of making an individual well bottom (12) of concrete in a mould comprising a disposable mould piece (1 ) according to any one of claims 1 - 4, an outer form (7), a bottom frame (8), a profile ring (10) and a top plate (11), c h a r a c t e r i z e d in that an outer form (7) is arranged on a bottom frame (8), and that a profile ring (10) is arranged at the bottom of the outer form on top of the bottom frame (8), that the disposable mould piece (1) is then secured to a top plate (11 ), which is arranged on top of the bottom frame (8) and is secured to it, that the disposable mould piece (1) is lubricated with a slip agent, that concrete is poured into the mould to the upper edge of the outer form, and that the well bottom (12) is removed from the mould after the curing has been completed.