EP3395521A1

EP3395521A1 - A mould

Info

Publication number: EP3395521A1
Application number: EP18169023.1A
Authority: EP
Inventors: Bernard Kennedy
Original assignee: Carlow Precast Manufacturing
Current assignee: Carlow Precast Manufacturing
Priority date: 2017-04-24
Filing date: 2018-04-24
Publication date: 2018-10-31
Also published as: IES20180131A2

Abstract

The present invention provides a split mould (10) for particular use in moulding large concrete components (12) having a weight bias to one end, the split mould (10) comprising a pair of mould sections (14, 16) separable from one another and defining a mould cavity (20) therebetween, and a guide member (18) which is adapted to allow the mould (10) to be rolled into an inverted position, in order to allow the mould (10) to be emptied.

Description

Field of the invention

The present invention is concerned with a mould, and in particular a mould used to manufacture components formed from concrete or the like.

Background of the invention

Conventionally, the moulding of structural concrete components, for example perimeter wall units for large concrete tanks or the like, is undertaken using conventional flat bed moulds. However, there are a number of disadvantages with this method. Removal from the mould generates considerable stress on the component, even under self weight. This therefore requires additional reinforcement to be designed into the component in order to stiffen the fresh concrete, which therefore results in a component which is reinforced above the level required for the in service conditions experienced by the component. Consequently, each component uses more material than is necessary, thereby increasing the cost of same, in addition to the weight thereof, rendering the component more difficult to manoeuvre/lift/etc.
Furthermore, the component generally has to be left in the mould for a minimum of 16 hours, in order to develop sufficient strength to allow removal from the mould. This therefore allows production of only one component per day, per mould. Additional production requires additional moulds, taking valuable space on the factory floor. Furthermore, only one concrete face has a high quality finish. The internal face is trowelled, thereby reducing the appearance of the quality of the product.
It is an object of the present invention to provide a mould facilitating the extraction of complex three-dimensional shapes in a manner which significantly redu stresses on the product.
It is a further object of the invention to provide a mould from which the product is released in a standing position therefore not subject to local forces which may otherwise define the design while low early-age strengths prevail.
It is a still further object of the present invention to provide a mould which is capable of producing a component having only in service reinforcement qualities required at demoulding.
It is an additional object of the present invention to provide a mould which allows production of multiple components per day.
It is a still further object of the present invention to provide a mould in which the extraction process is sympathetic to the component produced therefrom.
It is a further object of the invention to provide a mould from which extraction of the component should be possible using a conventional gantry crane, or similar lifting device.

Summary of the invention

According to a first aspect the present invention provides a split mould comprising two separable sections defining a cavity therebetween; and a guide member which is adapted to allow the mould to be rolled into an inverted position for demoulding.
Preferably, the guide member defines at least one curved support surface.
Preferably, the or each curved support surface extends between a base and a top of the mould.
Preferably, the curved support surface is a continuous surface.
Preferably, the guide member projects from one section of the mould.
Preferably, the split mould comprises at least one lifting point located on the other section of the mould.
Preferably, the guide member comprises a frame.
Preferably, the cavity is open at a top thereof, when the mould is in an upright position.
Preferably, when the mould is in the inverted position, the open top of the cavity is located substantially flush with a surface on which the mould has been rolled.
Preferably, the cavity is shaped and dimensioned, when in an upright position, to produce a top heavy component.
Preferably, the two sections of the mould are hinged together.
Preferably, the two sections of the mould are hinged together adjacent a base of the cavity.
Preferably, the split mould comprises a damper operable to effect the controlled roll of the mould into the inverted position.
Preferably, the damper is in the form of at least one spring biased retractable wheel which projects beyond the guide member such as to contact a surface on which the mould is being rolled.
Preferably, the split mould comprises a platform located to facilitate access to an open top of the cavity.
According to a second aspect the present invention provides a method of moulding a component, the method comprising the steps of filing a cavity of a mould with a flowable material; allowing the material to at least partially set; rolling the mould into an inverted position; and demoulding the component.
Preferably, the method comprises the step of rolling the mould into the inverted position on at least one guide member provided on the mould.
Preferably, the method comprises the step of separating two sections of the mould to facilitate demoulding.
Preferably, the method comprises damping the speed of rotation of the mould towards the inverted position.
As used herein, the term "upright" is intended to mean the orientation of a mould during the gravity fed filling of the mould cavity, which preferably occurs via an open upper face of the mould.
As used herein, the term "inverted" is intended to mean an orientation turned upside down or through approximately 180 degrees from an upright position.
As used herein, the term "top heavy" is intended to mean the state that a component is in due to shape and orientation, in which a greater proportion of the mass of the component is located about an upper portion of the component when in that orientation, generally resulting in an unstable component that has a risk of overturning.

Brief description of the drawings

The present invention will now be described with reference to the accompanying drawings, in which;

Figure 1 illustrates a perspective view of a mould according to the present invention;
Figure 2a - 2e illustrates, in schematic sectional view, the various stages in the process of rolling the mould of Figure 1 into an inverted position for demoulding; and
Figure 3 illustrates a partial end view of an optional damper which may be utilised on the mould of the present invention.

Detailed description of the drawings

Referring now to the accompanying drawings, there is illustrated a mould, generally indicated as 10, for use in manufacturing a structural component 12, in particular when formed from concrete or the like. It will however be appreciated from the following description of the invention that the component 12 need not be limited to the shape illustrated, and the mould 10 may be adapted to produce components (not shown) of any desired shape. The mould 10 is however particularly suited to producing large concrete components that are "tall" and relatively "thin", for example wall components, that as a result of their relative dimensions are conventionally difficult to demould due to the self weight of the component which can impose significant stresses on the component if stood in an upright or vertical orientation immediate following demoulding, resulting in potential damage to the component.
The mould 10 comprises two sections, which in the embodiment illustrated comprise a first half 14 and a second half 16 separable from one another, as will be described in detail hereinafter. It should be understood that the invention does not require the two separable sections to be formed as halves, and one section could be significantly larger that the other. It is also envisaged that the mould could have more that two sections separable from one another to allow for demoulding. The two halves 14, 16 may be formed from any suitable material or combination of materials, and may include any additional conventional features (not shown) which aid in the moulding and/or demoulding procedures.
The mould 10 is also provided with a guide member 18 which is shaped and dimensioned to enable the mould 10 to be rolled from an upright position, as illustrated in Figure 1, to an inverted position as shown in Figure 2d and generally about a longitudinal axis XX, again as will be described in detail hereinafter. It will be understood that the terms "upright" and "inverted" may refer only to the orientation of the mould 10 and not necessarily to the working orientation of the component being produced in the mould 10.
The first half 14 and the second half 16 together define a cavity 20, into which, in use, concrete or the like is poured in order to create the component 12. When in the upright position ready for filing with concrete the cavity 20 has a base 22, an open top 24, and shuttering 26 at either end of the cavity 20 in order to seal the ends of the cavity 20. The first half 14 and the second half 16 are also secured together, adjacent the base 22 of the cavity 20, by means of a hinge 28 or any other functional equivalent. Thus the mould 10 may be opened to facilitate demoulding of the component 12, as will be described hereinafter in detail.
The guide member 18 is comprised of a pair of frames 30 an outer face of each of which defines a curved or arcuate support surface, which are substantially semi-circular in profile in the preferred embodiment illustrated, the frames 30 being reinforced by the provision of a strut 32 extending therebetween. The frames 30 are secured to the first half 14, preferably at or adjacent either end thereof, in order to provide the maximum stability to the mould 10 during the rolling thereof. It will be appreciated from the following description of the operation of the mould 10 that the number, design and exact position of the frames 30 is not critical, and simply act to provide at least one and preferably a pair of the curved support surfaces spaced from one another to provide stability as the mould 10 is rolled into an inverted orientation as hereinafter described. The curved support surfaces preferably extend between the base 22 and the top 24 of the mould 10.
In the embodiment illustrated, the mould 10 is also provided with a platform in the form of a walkway 34, extending between the frames 30, which enables access to the top 24 of the cavity 20 when the mould 10 is in the upright position. It will be appreciated that the exact location and configuration of the walkway 34 may be varied once it provides access to the top 24 of the cavity 20.
Thus, in use, and referring to Figure 2a, the mould 10 is stood in an upright position, as illustrated in Figure 1, with the first half 14 and the second half 16 secured together by conventional releasably engagable locking means (not shown) which may be hydraulically or otherwise actuated. Wet concrete is then poured into the cavity 20, until the cavity 20 is filled flush to the top 24. The mould 10 is then left for a suitable period of time in order to set sufficiently to permit demoulding, which may vary depending on the composition of the concrete or other material used to fill the cavity 20. In order to provide increased stability to the mould 10 when in the upright position shown in Figure 1 and 2a, and also optionally when in the inverted orientation, each of the frames 30 preferably comprises a substantially horizontal element 30a extending between the curved portion of the frame 30 and the first half 14, the outer face of each element 30a being substantially flush with the top 24 or bottom 22 of the mould 10 in order to provide a footing to stabilise the mould 10 in the upright or inverted orientations.
Referring now to Figure 2A, it will be appreciated that the shape of the component 12, when inverted as in Figure 2A, will result in the component 12, and consequently the mould 10, being top heavy. At this point, the mould 10 is secured to a conventional gantry crane (not shown) or the like by means of suitable hardware provided on the mould 10, and preferably such as one or more steel eyelets or the like, preferably at or adjacent point A on the second half 16, being a position remote from the first half 14 and the frames 30. The gantry crane (not shown) is then operated to raise the mould 10, which will thus become unstable, due to the lowered and eccentric position of point A relative to the axis XX of rotation as defined by the curved support surfaces of the frames 30, which in conjunction with the top heavy state of the mould 10, will result in the mould 10 tending to topple over onto the first half 14. However, as the guide member 18 is mounted to the first half 14, the curved support surfaces of the frames 30 will constrain the mould 10 to a smooth rolling motion as it topple sideways. Thus, referring to Figure 2B, the mould 10 is shown as it begins to roll about the guide member 18, wherein the mould 10 will accelerate due to the top heavy nature of the component 12 therein. This acceleration will reduce significantly the load carried by the gantry crane, thereby resulting in slack developing in the rope (not shown) of the gantry crane, which must be compensated for by accelerating the uptake of the rope
Figure 2C shows the mould 10 having rolled beyond the horizontal, at which point the ropes of the gantry crane are again fully loaded. Raising of the mould 10 is continued in order to maintain the rolling motion of same. Thus, referring to Figure 2D, the mould 10 eventually reaches a fully inverted position, at which point the gantry crane is uncoupled from point A. Thus, when the mould 10 is completely rolled over, the component 12 is left sitting neatly on the factory floor, but still confined within the mould 10. The mould 10 is thus designed to place the underside of the finished component 12 on the factory floor at extraction. Thus the component 12 is positioned in its optimum configuration for strength on demoulding. In addition, during rotation of the mould 10 into the inverted position, the component 12 is completely confined, and therefore subject to no external forces.
The ropes (not shown) of the gantry crane (not shown) are then connected to the second half 16, at or adjacent point B. At this point, the locking means (not shown) securing the first half 14 and the second half 16 are uncoupled, and the gantry crane then actuated to raise the mould 10 away from the component 12, as illustrated in Figure 2D. Due to the hinged nature of the mould 10, the second half 16 will therefore pivot outwardly away from the component 12, leaving the component 12 exposed at one face. By continuing to raise the second half 16 the mould 10 will reach a fully open state, at which point further raising of the first half 14 results in the entire mould 10 being rotated away from the component 12, as is illustrated in Figure 2E. The profile of the component 12 is preferably designed such as not to present any obstacle to this path of removal. Thus the component 12 is left in a "fresh" state standing on the floor.
The mould 10 is then restored to its upright position, and manufacture of another component 12 can commence immediately. At this stage the mould 10 can be moved such that discharge of this second component (not shown) is not obstructed by the first component 12, which may not have gained sufficient strength to be moved using its cast in lifting inserts (not shown). Thus using this roll-over method, a conventional lifting frame (not shown) is not required, and at any time it is only necessary to lift half the mass of the mould 10 and component 12. Thus using this approach, the lifting requirement is reduced to approximately 40% of that required for conventional moulding methods.
However, it has been found that a characteristic of the mould 10 is that it is extremely difficult, if not impossible, to prevent the filled mould 10 from accelerating as it rolls towards the inverted position. Skilled crane operators can avoid this occurrence by anticipating the behaviour of the mould 10 as it rolls. However, unskilled operators react only after the event has occurred. The response of the crane controls are too slow to control the situation and the result is a shock and sideways loading on the crane. The implications are accelerated wear of the cranes ropes and guides (not shown), and a bouncing of the filled mould 10 due to the shock loading on the ropes.
Thus, referring to Figure 3, to prevent or reduce this acceleration of the mould 10 on passing the balance point thereof, a damper 36 may be provided to allow the gantry crane to keep pace with the rotating mould 10. A pair of the dampers 36 are preferably provided, one adjacent each of the pair of frames 30. Each damper 36 comprises a freely rotatable wheel 38, preferably pneumatic, mounted to a compressible hydraulic ram 40 at a position in which the wheel 38 projects partially radially outwardly of the curved support surface defined by the respective frame 30, the hydraulic ram 40 being arranged and positioned to allow the wheel 38 to be displaced effectively radially inwardly relative to the frame 30. A brace 42 is also secured between the first half 14 or the frame 30, and the wheel 38.
Thus, as the mould 10 rolls over on the pair of support surfaces defined by the frames 30, each wheel 38 will contact the ground, slowing the rotation of the mould 10. As the mould 10 continues to roll, the ram 40 will be compressed, forcing the wheel 38 inwardly, permitting the mould 10 to continue to roll along the ground contacting support surfaces of the frames 30. It will of course be appreciated that any other suitable damping mechanism (not shown) may be provided in place of the damper 36, while maintaining the functionality of same.
It will therefore be appreciated that the mould 10 of the present invention at least doubles productivity by allowing at least two of the components 12 to be produced every 24 hours. In addition, the mould 10 is considerably easier to manipulate in order to effect demoulding, while producing a product which has a significant increase in the quality of the external surfaces thereof.

Claims

A split mould comprising two separable sections defining a cavity therebetween; and a guide member which is adapted to allow the mould to be rolled into an inverted position for demoulding.
A split mould according to claim 1 in which the guide member defines at least one curved support surface.
A split mould according to claim 2 in which the or each curved support surface extends between a base and a top of the mould.
A split mould according to claim 2 or 3 in which the curved support surface is a continuous surface.
A split mould according to any preceding claim in which the guide member projects from one section of the mould.
A split mould according to claim 5 comprising at least one lifting point located on the other section of the mould.
A split mould according to any preceding claim in which the guide member comprises a frame.
A split mould according to any preceding claim in which the cavity is open at a top thereof, when the mould is in an upright position.
A split mould according to claim 7 in which, when the mould is in the inverted position, the open top of the cavity is located substantially flush with a surface on which the mould has been rolled.
A split mould according to any preceding claim in which the cavity is shaped and dimensioned, when in an upright position, to produce a top heavy component.
A split mould according to any preceding claim in which the two sections of the mould are hinged together.
A split mould according to any preceding claim in which the two sections of the mould are hinged together adjacent a base of the cavity.
A split mould according to any preceding claim comprising a damper operable to effect the controlled roll of the mould into the inverted position.
A split mould according to claim 13 in which the damper is in the form of at least one spring biased retractable wheel which projects beyond the guide member such as to contact a surface on which the mould is being rolled.
A method of moulding a component, the method comprising the steps of filing a cavity of a mould with a flowable material; allowing the material to at least partially set; rolling the mould into an inverted position; and demoulding the component.