Patent Description:
<FIG> shows a known method for simultaneously forming a plurality of piles by pouring concrete into an elongate mould. Before the concrete is poured into a mould <NUM>, post-tension cables <NUM> are first placed in mould <NUM>. These are for instance unwound from a roll situated at a first outer end of mould <NUM>. A pulling device <NUM>, with which post-tension cables <NUM> can be pulled through mould <NUM> toward the second outer end, can optionally be provided at the opposite, second outer end of mould <NUM>. Before post-tension cables <NUM> are pulled toward the second outer end by pulling device <NUM>, an end surface partition <NUM> is first placed in mould <NUM>. An example of an end surface partition <NUM> is shown in <FIG> at top left.

<FIG> shows an example wherein two piles <NUM> are manufactured by means of a single end surface partition <NUM>. It must be noted that this is merely a simplified representation. Mould <NUM> can thus have a length of more than <NUM> metres, wherein a plurality of end surface partitions <NUM> is used. The length of a pile <NUM> can for instance lie between <NUM> and <NUM> metres.

End surface partition <NUM> comprises a pair of side walls <NUM>, <NUM> which are placed at a mutual distance and which are connected by an upper wall <NUM>. A first side wall <NUM> forms here the underside of a pile <NUM> and a second side wall <NUM> the upper side of another pile <NUM>. Second side wall <NUM> is usually provided with a recess 102A through which pile <NUM>, shown at bottom left, is provided on an upper side with a convex portion 4A.

Shown in the centre of <FIG> is a top view of mould <NUM> with placed therein end surface partition <NUM> and three post-tension cables <NUM> for the formation of two piles <NUM>. Mould <NUM> comprises a mould bottom 1A and mould side walls 1B.

An example of a pile <NUM> made with mould <NUM> is shown at left in <FIG>. The schematic view of end surface partition <NUM> at top left in <FIG> and the cross-sections of end surface partition <NUM> at two different positions in the longitudinal direction of mould <NUM> show openings <NUM> in first side wall <NUM> and second side wall <NUM>, through which post-tension cables <NUM> are passed. In order to pass post-tension cables <NUM> through openings <NUM> a user must manually insert an end of a post-tension cable <NUM> through opening <NUM> and then string end surface partition <NUM> onto post-tension cables <NUM>. After this, the ends of post-tension cables <NUM> can be engaged by pulling device <NUM>. For this purpose pulling device <NUM> can comprise a pulling plate to which post-tension cables <NUM> are attached. Pulling device <NUM> can further comprise a winch with which the pulling plate is pulled toward the second end. Once attached at the second outer end, post-tension cables <NUM> can be pre-tensioned by a pulling device <NUM>. Once pre-tensioned, post-tension cables <NUM> are further fully tensioned by means of pulling device <NUM>. After the pre-tension has been applied, cage reinforcement can likewise be positioned in mould <NUM> at the end surface partitions and be coupled to post-tension cables <NUM>. This cage reinforcement serves to strengthen pile <NUM> close to the head and foot of pile <NUM>.

As subsequent step, mould <NUM> is poured full of concrete. Two piles <NUM> are hereby formed more or less simultaneously. After the concrete has cured, end surface partition <NUM> must be removed. For this purpose a user must cut through post-tension cables <NUM> in the space of an end surface partition <NUM> between the first and second side walls <NUM>, <NUM>. Piles <NUM> can then be removed from wall <NUM>, for instance using vacuum lifting equipment. During this removal, end surface partition <NUM> will also be pulled out of mould <NUM> because it is still coupled to the post-tension cable ends protruding from pile <NUM>. A user must then separate end surface partition <NUM> from pile <NUM>. As final step, the post-tension cable ends must be cut off.

The above method for manufacturing piles is particularly labour-intensive, particularly the stringing of the end surface partitions onto the post-tension cables and the removal of the end surface partitions from the mould.

<CIT> discloses a splicing device for concrete structural members that includes two mating connectors positioned in axial alignment adjacent to each other that are interlocked by a key inserted through a keyway provided in the sidewalls of the connectors. Prestressing strands in the structural members to be spliced are fastened to the connectors by inserting them into axial holes located in the ends opposite the mating ends of the connectors, and thereafter wedging the strands within frustum-shaped cavities forming part of the holes, by means of frustum-shaped segments, or feathers, forced against the elements within the cavities.

<CIT> discloses a milling device for wire reinforced cast concrete article that includes means for tensioning reinforcing wires when in working position.

<CIT> discloses a strand holder and dam for prestressed concrete moulds.

An object of the present invention is to provide an end surface partition whereby a plurality of piles or other type of elongate concrete product can be formed in a less labour-intensive manner.

According to the present invention, this object is achieved with the end surface partition according to claim <NUM>, which is configured to mutually separate elongate concrete products which are formed by pouring concrete into and curing concrete in an elongate mould with the end surface partition and one or more post-tension cables placed therein. According to the present invention, the end surface partition comprises a wall comprising a slot in which at least one of the one or more pre-tension cables can be received. The end surface partition further comprises confining means which are configured to confine the pre-tension cable(s) received in the slot in order to ensure a respective minimum penetration depth into the slot for each received pre-tension cable. The end surface partition also comprises operating means for releasing the confinement by the confining means so that the end surface partition can be removed from the elongate mould, wherein the operating means are configured so that they can be operated after pouring and at least partial curing of the concrete in the elongate mould.

Making use of a slot in which the pre-tension cable(s) can be confined makes it possible to place the end surface partition in simple manner. This is because, in the known end surface partition, the pre-tension cables had to be passed through openings in the end surface partition. With the end surface partition according to the present invention the end surface partition is placed over the pre-tension cable(s) such that the pre-tension cable(s) enter(s) the slot. Such a placing is much less intensive than stringing end surface partitions onto pre-tension cables.

The confining means provide for a determined positioning of the pre-tension cable(s) relative to a bottom of the mould. Without confining means, the pre-tension cable(s) would sag, whereby the position of the pre-tension cable(s) relative to the bottom of the mould would become highly dependent on the position in the longitudinal direction of the mould and could even come into contact with the bottom of the mould. In respect of the known end surface partition, confinement of the pre-tension cable(s) to prevent the pre-tension cable(s) from entering further into the slot is not necessary or not present.

The operating means can also be configured to, by engagement thereof, remove the end surface partition from the elongate mould after at least partial curing of the concrete. The operating means can thus be configured to remove the end surface partition from the elongate mould after at least partial curing of the concrete by means of pulling on the operating means. The operating means can particularly be configured to, when pulled, perform a movement wherein the confinement is released and wherein the end surface partition can simultaneously or contiguously be removed from the mould.

The confining means can comprise a first arm which is connected pivotally to the wall and which can be moved between a first position, in which position the first arm overlaps the slot at least partially, and a second position, in which position the first arm does not overlap the slot, or hardly so. The first arm is here movable from the first position to the second position by engagement with a pre-tension cable which moves into the slot, and wherein the confining means are configured to hold the first arm in the first position when engaging with a pre-tension cable which wants to move out of the slot. The first arm can for instance comprise an end which, with the first arm in the first position, prevents the pre-tension cable in the slot from dropping toward the bottom of the mould below a determined height relative to the bottom of the mould.

The operating means can be translatable in a direction parallel to the slot. The confining means can also comprise a connecting element which is connected pivotally to the first arm and which is connected pivotally to the operating means. By operating the operating means, more particularly by translating the operating means, the first arm will pivot with interposing of the connecting element. The wall can here comprise a first plate part in which the slot is arranged and the operating means can comprise a second plate part which is attached slidably to the first plate part. The first plate part can further comprise a slotted hole and the second plate part can comprise a coupling element, such as a pin, whereby the second plate part is coupled slidably to the first plate part. It is however also possible for the second plate part to comprise a slotted hole and the first plate part a coupling element, such as a pin, whereby the first plate part is coupled slidably to the second plate part. Using a plurality of slotted holes and a plurality of coupling elements makes it possible to limit the freedom of movement of the second plate relative to the first plate, for instance to just the above stated translating movement in the longitudinal direction of the slot.

The connecting element can be a rigid element which is connected pivotally to the second plate part at a pivot point, wherein the pivot point is configured to move relative to the connecting element or the second plate part when the first arm moves from the first position to the second position. The connecting element can for instance comprise a slotted hole, wherein the second plate part comprises a coupling element, such as a pin, which engages in the slotted hole and thus forms a hinge for pivoting the connecting element relative to the second plate part. It is however also possible for the second plate part to comprise a slotted hole and the connecting element a coupling element, such as a pin, which engages in the slotted hole and thus forms a hinge for pivoting the connecting element relative to the second plate part.

The connecting element can be a rigid element which is connected pivotally to the second plate part at a pivot point, wherein the pivot point is stationary relative to the connecting element and the second plate part when the first arm moves from the first position to the second position. In this case the first arm can move from the first position to the second position by the mutual translation of the first and second plate part.

The connecting element can however also be a flexible element which can move between a taut state, in which further extension of the flexible element is not possible, or hardly so, and a slack state. The connecting element can be configured to, in the taut state, hold the first arm in the first position upon engagement with a pre-tension cable which wants to move out of the slot and to move from the taut state to the slack state by engagement with a pre-tension cable which moves into the slot.

The wall can comprise a plurality of the above stated slots, wherein each slot is configured to receive at least one of the one or more pre-tension cables. Additionally or instead, the slot can be configured to receive a plurality of pre-tension cables per slot, wherein the confining means are configured to ensure a respective minimum penetration depth into the slot for each received pre-tension cable.

The end surface partition comprises a first side wall and a second side wall, wherein the end surface partition is configured to simultaneously form a first end surface of a first elongate concrete product with the first side wall and a second end surface of an adjacent, second elongate concrete product with the second side wall during pouring of the concrete into and curing of the concrete in the elongate mould. The above stated wall is placed between the first side wall and second side wall.

The top of a pile, i.e. the side which is struck during placing of the pile, can comprise a protrusion for better distribution of the exerted forces. The inverse of this shape can be arranged in the first or second side wall. The first or second side wall can for instance be provided with a recess.

The first side wall is provided at a surface thereof which is directed toward the first elongate concrete product to be formed with a first flexible sealing layer comprising a first cut which coincides with the slot. The second side wall is also provided at a surface thereof which is directed toward the second elongate concrete product to be formed with a second flexible sealing layer comprising a second cut which coincides with the slot. The first and second flexible sealing layer are configured to prevent concrete from entering the end surface partition during pouring of the concrete and/or curing thereof.

The first and second side walls can be configured to pivot toward each other to enable the end surface partition to be released from the mould. After pivoting, the end surface partition will widen in upward direction, as seen from the bottom of the mould. The end surface partition can here comprise an upper wall, wherein the first side wall and second side wall are pivotally connected to the upper wall to enable the first and second side wall to be pivoted toward each other. The upper wall can be provided at a side remote from the mould with a third sealing layer to prevent or impede concrete from entering the end surface partition from an upper side during pouring of the concrete. This third sealing layer can comprise a third cut through which the operating means extend outward.

The operating means can be configured to, when engaged, pivot the first and second side walls toward each other. The end surface partition can thus comprise a first coupling arm which couples the first side wall pivotally to the operating means and a second coupling arm which couples the second side wall pivotally to the operating means, such that when the operating means are engaged, the first and second side walls pivot toward each other.

The first and second coupling arm can here each be pivotally connected to the second plate part.

According to a second aspect of the present invention, a method is provided for simultaneously forming elongate concrete products, such as piles. The method comprises here the steps of arranging one or more pre-tension cables in an elongate mould, placing an end surface partition according to the present invention in the elongate mould, sliding the pre-tension cable(s) into the slot or slots of the end surface partition such that it is/they are confined in the slot or slots, pouring concrete into and allowing at least partial curing of concrete in the elongate mould, and operating the operating means of the end surface partition and removing the end surface partition from the elongate mould.

Prior to placing of the end surface partition in the elongate mould, the one or more post-tension cables can be pre-tensioned. The tension in the one or more pre-tension cables can further be increased after the end surface partition is placed in the elongate mould.

The present invention will be discussed further hereinbelow with reference to the accompanying figures, wherein the same or similar components will be designated with identical reference numerals and wherein:.

<FIG> shows an embodiment of an end surface partition <NUM> according to the present invention, which is placed in a mould <NUM> having a mould bottom 1A and mould side walls 1B. End surface partition <NUM> comprises a first side wall <NUM> which is provided with a flexible sealing layer, for instance made of polyurethane. This sealing layer comprises a cut 101A which coincides with a slot <NUM> of end surface partition <NUM> as shown in <FIG>. The sealing layer prevents liquid concrete from entering end surface partition <NUM>. As shown, end surface partition <NUM> comprises three slots <NUM> in which a total of five post-tension cables <NUM> are received. A handle 104A connected to second plate part <NUM>, as will be elucidated in <FIG>, further protrudes from upper wall <NUM>.

<FIG> shows a perspective side view of the end surface partition of <FIG>. An internal mechanism <NUM> of end surface partition <NUM>, which will be further elucidated in <FIG> and <FIG>, is visible here. <FIG> shows that internal mechanism <NUM> comprises a transverse connection <NUM> which is connected by means of hinges 112A, 112B to support parts 113A, 113B of respectively first side wall <NUM> and second side wall <NUM>. It can further be seen that support part 113B is connected pivotally to second plate part <NUM> by means of hinge <NUM>, coupling arm <NUM>, second hinge <NUM> and plate part <NUM>. Support part 113A is connected pivotally to second plate part <NUM> in similar manner. <FIG> also shows a recess 102A for the formation of a protrusion 4A of pile <NUM> as shown in <FIG>.

<FIG> shows schematically the operation of a part of internal mechanism <NUM> and shows the confinement of a post-tension cable <NUM> as according to the present invention.

Internal mechanism <NUM> comprises a first plate part <NUM> and a second plate part <NUM>. First plate part <NUM> is provided with a slot <NUM> in which a post-tension cable <NUM> is received. First plate part <NUM> is connected pivotally to an arm <NUM> by means of a hinge <NUM>, which arm is in turn connected to second plate part <NUM> by means of a hinge <NUM>, rigid coupling arm <NUM> and hinge <NUM>. Hinge <NUM> is here formed by a pin which is fixed to coupling arm <NUM> and which can translate in a slotted hole <NUM>.

The figure at top left in <FIG> shows that a post-tension cable <NUM> moves upward in slot <NUM>. If post-tension cable <NUM> comes into contact with first arm <NUM>, which lies partially over slot <NUM>, post-tension cable <NUM> pushes hinge <NUM> to the right as shown at top right in <FIG>. If post-tension cable <NUM> moves further into slot <NUM>, first arm <NUM> will return to the position as shown at top left in <FIG>.

Hinge <NUM>, arm <NUM>, hinge <NUM>, coupling arm <NUM> and hinge <NUM> form part of confining means which can confine post-tension cable <NUM>. The operation of these confining means is as follows. If post-tension cable <NUM> moves further into slot <NUM>, on the basis of the situation at top right in <FIG>, arm <NUM> will move back to the position shown at top left in <FIG>. This situation is shown at bottom left in <FIG>. Arm <NUM> can optionally be under spring tension in order to bring about this movement. If post-tension cable <NUM> moves downward in this position of arm <NUM>, arm <NUM> will block this movement. This is because post-tension cable <NUM> presses on arm <NUM>, whereby hinge <NUM> runs up against an end of slotted hole <NUM>.

The confinement can be released by translating second plate part <NUM> relative to first plate part <NUM>. Other relative movements of first plate part <NUM> and second plate part <NUM> for the purpose of releasing the confinement are not precluded.

By moving second plate part <NUM> upward, for instance by pulling handle 104A, arm <NUM> is pulled out of engagement with post-tension cable <NUM> and the situation as shown at bottom right in <FIG> is reached.

In the embodiment shown in <FIG> post-tension cable <NUM> can push arm <NUM> away during an upward movement in slot <NUM>. This is possible in that hinge <NUM> is able to move in slotted hole <NUM>.

In another embodiment hinge <NUM> is unable to move, and coupling arm <NUM> is coupled to second plate part <NUM> at a fixed position. In such a case arm <NUM> can only move away by moving second plate part <NUM> upward. Confinement can be achieved by moving second plate part <NUM> back down at the moment that post-tension cable <NUM> is positioned sufficiently high in slot <NUM>.

<FIG> shows an alternative embodiment wherein, in contrast to <FIG>, coupling arm <NUM> does not take a rigid form but a flexible form. In the position of arm <NUM> shown at top left in <FIG> coupling arm <NUM> is here in a taut state, wherein coupling arm <NUM> is not extendable, or hardly so. If arm <NUM> is however engaged by a post-tension cable <NUM>, as shown at top right in <FIG>, coupling arm <NUM> will take on a slack state and arm <NUM> will be moved by post-tension cable <NUM>. Confinement is in this embodiment similar to that shown at bottom left in <FIG>, with the difference that further movement of coupling arm <NUM> is prevented in that further extension of coupling arm <NUM> is impossible, as opposed to hinge <NUM> running up against an end of slotted hole <NUM>. Releasing the confinement proceeds similarly to the figure at bottom right in <FIG>.

Coupling arm <NUM> can comprise a resilient element which presses first arm <NUM> against a stop <NUM>. In such a case confinement is achieved in that arm <NUM> lies against stop <NUM>. In this case the confinement can also be released by moving first plate part <NUM> and second plate part <NUM> relative to each other. A post-tension cable <NUM> which is placed in slot <NUM> will here move counter to the spring tension in arm <NUM> and coupling arm <NUM>.

<FIG> and <FIG> show internal mechanism <NUM> of the end surface partition of <FIG> and <FIG> in two different states. <FIG> shows the situation in which arm <NUM> is in a position for confining a post-tension cable and <FIG> a situation in which a post-tension cable can move up and downward in slot <NUM>. Compared to the schematic operation shown in <FIG>, it is noted that the embodiment in <FIG> and <FIG> has three slots and, per slot, two confining means for confining different post-tension cables <NUM> at different heights. It is further noted that the position of the middle post-tension cable in <FIG> does not correspond with the position shown in <FIG> and <FIG>, but it will be apparent that the same operating principle can be applied.

Second plate part <NUM> further comprises slotted holes <NUM> and first plate part <NUM> comprises pins <NUM> which engage in slotted holes <NUM>. The use of a plurality of slotted holes <NUM> and pins <NUM> limits the relative movement of first plate part <NUM> and second plate part <NUM> to a translation. It is further shown that plate part <NUM>, likewise shown in <FIG>, is coupled to second plate part <NUM>.

<FIG> and <FIG> show the embodiment of <FIG> and <FIG> corresponding to the states of respective <FIG> and <FIG>. In <FIG> the second plate part <NUM> has been moved upward. Side walls <NUM>, <NUM> have hereby pivoted inward relative to the situation shown in <FIG>. It can further be seen that upper wall <NUM> comprises parts 104B, 104C which connect to side walls <NUM>, <NUM> in the situation shown in <FIG>, but which are located at a distance in <FIG>.

The operation of the end surface partition of <FIG> and <FIG> will be elucidated hereinbelow. On the basis of a situation in which post-tension cables <NUM> have been pre-tensioned in mould <NUM>, end surface partitions <NUM> are placed over post-tension cables <NUM>. First plate part <NUM> and second plate part <NUM> are here in the position as shown in <FIG>. Owing to engagement of the post-tension cables on arms <NUM> they will move from the position as shown at top left in <FIG> to the position as shown at top right in <FIG>. A user will here generally pull post-tension cables <NUM> upward in slot <NUM> because, in the pre-tensioned state, they do not have the height which corresponds with the height reached in slot <NUM> after post-tension cables <NUM> have been confined therein. In practice, the user will move post-tension cable <NUM> to a position above the desired height in slot <NUM>, after which arm <NUM> can take up the desired position for confinement of post-tension cables <NUM>.

After end surface partitions <NUM> have been placed, the concrete can be poured. If the concrete has cured sufficiently, the user can operate handle 104A, whereby side walls <NUM>, <NUM> pivot inward on one hand and the downward movement of post-tension cables <NUM> in slot <NUM> is released on the other. This makes it possible to remove end surface partition <NUM> from mould <NUM> without post-tension cables <NUM> having to be cut. After removal of end surface partitions <NUM>, post-tension cables <NUM> can be cut very close to the end surfaces of the formed piles. The piles can then be removed from mould <NUM>.

Claim 1:
End surface partition (<NUM>) for mutually separating elongate concrete products which are formed by pouring concrete into and curing concrete in an elongate mould (<NUM>) with the end surface partition (<NUM>) and one or more post-tension cables (<NUM>) placed therein, the end surface partition (<NUM>) comprising:
a wall comprising a slot (<NUM>) in which at least one of the one or more pre-tension cables (<NUM>) can be received;
confining means which are configured to confine the pre-tension cable(s) (<NUM>) received in the slot (<NUM>) in order to ensure a respective minimum penetration depth into the slot (<NUM>) for each received pre-tension cable (<NUM>);
operating means for releasing the confinement by the confining means so that the end surface partition (<NUM>) can be removed from the elongate mould (<NUM>), wherein the operating means are configured so that they can be operated after pouring and at least partial curing of the concrete in the elongate mould (<NUM>);
wherein the end surface partition (<NUM>) further comprises a first side wall (<NUM>) and a second side wall (<NUM>), wherein the wall is placed between the first side wall (<NUM>) and second side wall (<NUM>) and wherein the end surface partition (<NUM>) is configured to simultaneously form a first end surface of a first elongate concrete product with the first side wall (<NUM>) and a second end surface of an adjacent, second elongate concrete product with the second side wall (<NUM>) during pouring of the concrete into and curing of the concrete in the elongate mould (<NUM>);
characterized in that the first side wall (<NUM>) is provided at a surface thereof which is directed toward the first elongate concrete product to be formed with a first flexible sealing layer, wherein the first sealing layer comprises a first cut (<NUM> A) which coincides with the slot (<NUM>), and wherein the second side wall (<NUM>) is provided at a surface thereof which is directed toward the second elongate concrete product to be formed with a second flexible sealing layer, wherein the second sealing layer comprises a second cut which coincides with the slot (<NUM>).