The present invention relates to a method of casting a body of concrete having a surface part defining a recess and including a lifting member having a first end portion anchored in the concrete body and a free second end portion extending into the recess.

In order to facilitate transporting, placing and other handling of heavy bodies of concrete, such as large con¬ crete pipes, it is conventional to cast such concrete bodies with lifting members or lifting anchors having one end portion embedded in the concrete material and a free end, which is adapted to be connected to lifting equipment or lifting gear, extending from the outer surface of the concrete body. Usually, the free end of the lifting member extends into a recess formed in the outer surface of the body, so that the lifting member or lifting anchor does not extend beyond the maximum outer dimension of the body.

It is known to cast such concrete pipes in a mould having a mould cavity defined by walls having one or more openings therein, which may be closed by closure plates being fastened to the mould wall by screws or bolts. A unitary, hemispherical filler member or recess plug with a pair of jaws interconnected by a hinge portion is screw-fastened to the inner side of each closure plate with the jaws in a closed position. Before fastening the filler member to the closure plate, the second end portion of the lifting mem¬ ber, which is to be exposed in the recess to be formed, is arranged between and held by the jaws of the filler member. Concrete is now poured into the mould cavity and compacted, for example by vibration, while the lifting member and the filler member are held in position in relation to the closure plate and the mould by means of the screw connec¬ tions.

After pouring and compacting the concrete the closure plate is released and the jaws of the filler member or recess plug are opened, whereafter the filler member is removed through the mould opening. It has been proposed to release the screw connection between the closure plate and the filler member or recess plug, but to leave the filler member in the recess of the cast concrete body until the concrete has set to avoid deformation of the recess. It is also known to cast concrete pipes of the above type with lifting anchors or lifting members in a mould in which the lifting members or lifting anchors are automatically with¬ drawn from a magazine and arranged in position within the mould cavity. This known apparatus comprises a filler head, which is movable by means of a fluid cylinder from a re- tracted position in which a lifting member or lifting anchor is fed from the magazine into the filler head, to an advanced position in which the free end portion of the filler head extends into the wall opening of the mould and closes the opening, while the lifting member is held in a moulding position. When concrete has been poured into the mould and compacted the filler head is released from the lifting member and moved to its retracted position prior to removing the cast concrete pipe from the mould cavity. This means, that the concrete being poured into the mould must have a rather stiff consistency in order to avoid deforma¬ tion of the recess being formed.

The present invention provides an improved method of cast¬ ing a concrete body of the above type, said method compri¬ sing releasably mounting said second end portion of the lifting member between a pair of jaws of a filler member, so that said first end portion of the lifting member is exposed, releasably connecting the filler member to a supporting device, moving the filler member and the lifting member mounted therein into the cavity of a mould through an opening defined in a wall part of the mould to a moul¬ ding position, in which said first end portion of the

lifting member is exposed in the mould cavity and the filler member is positioned totally inside the inner wall surface of the mould, filling concrete into the mould cavity while retaining the filler member and the lifting member in said position by means of the supporting device, so as to form said concrete body in which the recess is filled out by the filler member, releasing the supporting device from the filler member after the filling of concrete into the mould cavity, and subsequently removing the cast concrete body from the mould cavity with the filler member nested in the recess, and the method according to the invention is characterized in moving the jaws of the filler member to a closed position by means of the supporting device, in which position the second end portion of the lifting member is pinched between the jaws and the filler member is interlocked with the supporting device. Thus, the supporting device may simultaneously lock the lifting member to the filler member and the filler member to the supporting device prior to moving the filler member and the lifting member into the mould cavity by means of the sup¬ porting device. Similarly, when concrete has been filled into the mould cavity the supporting device may be released from the filler member before the cast concrete body is removed from the mould, and the filler member may be left in the recess of the cast concrete body until the concrete has set, whereby deformation of the recess is avoided. The method according to the invention may be performed by a manually operated or an automatic or semi-automatic opera¬ ting moulding apparatus. The lifting member or lifting anchor as well as the filler member used may be of any suitable type. Preferably, it should be possible to release the filler member positioned in the recess of the moulded concrete body from the lifting member having its one end embedded in the concrete without damaging or disintegrating the filler member so that it may be re-used. Alternatively, the filler member may be of a relatively cheap disposable type which is to be used only once. As an example, the

filler member may be of a type known per se, in which the jaws are interconnected by hinge means formed by a connec¬ ting part being more or less flexible or bendable, said jaws having an outer contour forming part of a circle having its centre on the axis of the hinge means. The filler member may be made from two or more separate parts, which may be disconnected when the filler member is removed from the recess of said concrete body. Preferably, however, the filler member is a unitary member made from a flexible material such as rubber or plastic material.

The supporting device should be connectable to and releas- able from the filler member. The connecting means for mutually connecting the supporting device and the filler member may be of the stud-and-socket type. In the preferred embodiment, the supporting device is connected to and released from the filler member by moving stud-like connec¬ ting members of the supporting device into and out from bores formed in the jaws of the filler member. Alternative¬ ly, projections formed on the jaws of the filler member could be received in socket-like connecting members of the supporting device.

The stud-like connecting members may be moved individually into and out of engagement with the bores of the filler member and may extend in different directions. In the preferred embodiment, however, the stud-like connecting members are moved into and out of engagement with the bores of the filler member in a mutually parallel position. In the latter case the engagement and disengagement of the connecting members may be obtained by moving the supporting device in a direction parallel with the axial direction of the connecting members. When the stud-like connecting members have been moved into engagement with the jaws of the filler member, these jaws may be moved to their closed position by mutually tilting the connecting members to a position in which they define an acute angle therebetween.

whereby the lifting member is pinched between the jaws, and the stud-like connecting members cannot be retracted from the bores of the jaws before the connecting members are moved back to their mutually parallel position.

When the supporting device and the filler member are inter¬ connected by means of stud-like connecting members, they may be locked together by moving the connecting members in relation to each other, for example by tilting the connec¬ ting members as indicated above. The connecting members may be moved in relation to each other by means of a toggle device or by any other suitable force transmitting device.

When the cast concrete member has set it should be possible to remove the filler member from the recess formed therein as explained above. Therefore, the supporting device may comprise an abutment member defining an abutment surface thereon for abutting engagement with the filler member when connected to the supporting device. This means that the filler member surface being in abutting engagement with the abutment surface of the supporting device will be exposed at the surface of the concrete body being cast. The opening in the mould wall through which the filler member is inser¬ ted into the mould cavity should preferably be substantial¬ ly closed before concrete is filled into the mould cavity. Therefore, this opening may be substantially closed by means of the abutment member in the moulding position of the filler member, and the abutment surface of the abutment member may substantially flush with or be located inside the adjacent inner wall part of the mould, so that the filler member cannot interfere with the opening when the cast concrete member is removed from the mould.

The supporting device could, for example, be moved between the said moulding position and a retracted position, for example by means of a fluid cylinder unit, which is mounted stationarily in relation to the mould, and the abutment

member could then be biassed towards the mould wall by the fluid pressure of the fluid cylinder unit. Alternatively, the supporting device may be a separate, manually operated device, which is manually moved to the opening of the mould wall. Such movement could, for example, be guided in rela¬ tion to the mould by suitable guide means, such as a lin¬ kage. The supporting device may then be retained in said moulding position by means of releasable clamping means for forcing a rim portion of the abutment member against an outer surface part of the mould. The supporting device may then be released from the filler member, while the abutment member is still forced against the outer surface part of the mould, whereby the filler member is prevented from being moved out of the recess formed in the concrete body. In order to allow movement of the stud-like connecting members between the positions in which they release and lock the filler member to the supporting device, respec¬ tively, the connecting members may extend through openings formed in the abutment member, and be moved in relation thereto.

The present invention also relates to a supporting device for use in carrying out the method described above, said supporting device comprising an abutment member having an abutment surface for abutting engagement with the filler member, and stud-like connecting members extending through openings defined in the abutment member, and the supporting device according the to the invention is characterized in an actuating mechanism for moving the connecting members from a releasing position, in which the connecting members extend substantially parallel, and a locking position, in which the connecting members are converging towards their free ends. This supporting device may be a separate, por¬ table device, which is power-operated or manually operated. Alternatively, the supporting device may be an automatic or semi-automatic operating device, which is mounted statio¬ narily in relation to the mould. Despite the fact whether

the supporting device is manually or power operated, its movements in relation to the mould may be defined by guide means, such as guide rails or a linkage defining the move¬ ment of the supporting device between an operative or moulding position, and an inoperative position in which the filler member and the lifting member are mounted on the supporting device.

The actuating mechanism may comprise mechanical mechanisms, such as toggle devices, electromechanical devices, such as solenoid operated devices, and hydraulic and pneumatic devices, such as hydraulic and pneumatic cylinder units. As an example, the toggle device may comprise a slide member mounted movably in relation to the abutment member and first link members each being pivotally connected to the slide member and one of the connecting members, respec¬ tively.

The present invention also provides a mould comprising a wall part defining an opening communicating with the mould cavity and comprising a supporting device as that described above.

The invention will now be further described with reference to the drawings, wherein

Figs. 1-6 diagrammatically illustrate various steps of an embodiment of the method according to the present inven- tion.

Fig. 7 is a plan view and partially sectional view showing an embodiment of the supporting or mounting device accor¬ ding to the invention used in connection with a concrete mould, Fig. 8 is a side view of the device shown in Fig. 7 in its locked position, and

Fig. 9 is a side view as that in Fig. 8, but with the device in its released position.

Fig. 1 shows a filler member or recess plug 10 having a semicircular outline 11 and a radially extending slit 12, which divides the recess plug into a pair of jaws 13 inter¬ connected by a hinge portion 14 defining a hinge axis extending transversely through the centre of the circular outline 11. The recess plug 10 is preferably a unitary member made from rubber or plastic material and may, for example, have a hemispherical shape or be shaped like a semi-circular disc. Thus, in its neutral, non-stressed position (Figs. 2 and 5) , the recess plug defines a sub¬ stantially plane surface 15, and each jaw 13 defines there¬ in a bore 16, Fig. 3, opening in the plane surface 15 and extending substantially mutually parallel in the non- stressed condition of the recess plug.

The recess plug 10 is adapted to receive one end portion of a lifting member or lifting anchor 17, which is preferably made from steel or another metal. The lifting anchor 17 has a bobbin-like shape with flange portions 18 and 19 at its free end. Opposed jaw surfaces 20 are recessed to define a shape, which is substantially complementary to the outer shape of the flange portion 19 and the adjacent end part of the lifting anchor 17, so that the said one end portion of the lifting anchor 17 may be fully enclosed in the recess plug 10 as shown in Fig. 2.

The recess plug 10 may be mounted in a mould 21 by means of a supporting or mounting device 22 which will be described in more detail below with reference to Figs. 7-9. The mounting device 22 comprises a pair of stud-like connecting members 23 and a closure plate 24. The connecting members 23 extend through openings 25 defined in the closure plate 24 and are movable in relation to the closure plate and also in relation to each other.

In Fig. 2 the connecting members 23 are arranged substan¬ tially parallel with a mutual spacing corresponding sub-

stantially to the spacing of the bores 16 in the recess plug 10. Therefore, the parallel connecting members 23 may be moved through the openings 25 and into engagement with the bores 16 of the plug 10. When the connecting members 23 have been fully received in the bores 16, and the surface 15 of the plug 10 is in abutting engagement with the clo¬ sure plate 24 the connecting members 23 are tilted to a mutually converging position shown in Fig. 3, whereby the jaws 13 of the recess plug 10 are pressed into engagement with each other so that the lifting anchor 17 is held safely therebetween. In this position, the connecting members 23 are locked to the recess plug 10 and cannot be retracted from the bores 16.

The unit illustrated in Fig. 3 and comprising the mounting device 22, the recess plug 10 and the lifting anchor 17 may now be mounted in an opening 26 defined in a wall part of the mould 21 so that the opening 26 is substantially closed by the closure plate 24, and the recess plug 10 with the lifting anchor 17 extending into the cavity of the mould, vide Fig. 4. Concrete 27 may now be introduced into the mould cavity and, subsequently, the connecting members 23 may be moved to their mutually parallel position and with¬ drawn from the recess plug 10. The connecting members 23 are preferably withdrawn prior to settling and possible compacting of the concrete 27. This means that during such settling of the concrete the recess plug 10 and the lifting anchor 17 may freely move in relation to the wall of the mould 21 as indicated in Fig. 5 whereby improved anchoring of the lifting anchor 17 in the concrete 27 may be ob- tained. When the concrete body moulded has been removed from the mould 21 the recess plug 10 may remain in its position therein until the concrete has set. Thereafter, the plug 10 may be removed by opening its jaws 13, for example in a known manner by means of rod members which are inserted in the bores 16 of the plug 10. A recess 28 having an end portion 29 of the lifting anchor 17 exposed therein

has now been formed in the outer wall of the moulded con¬ crete body, which may, for example, be a concrete pipe.

As illustrated in Figs. 7-9, the supporting or mounting device 22 comprises a slide member 30, which is pivotally connected to the stud-like connecting members 23 by means of links 31, and the slide member 30 is movable along a guiding rod 32, which is fastened to the closure plate 24, for example by welding, and which extends from the outer surface of the closure plate at substantially right angles. The mounting device 22 is operated by means of a handle 33, which is swingably mounted about a pivot axis defined by a pivot member 34. The pivot member 34 is fixedly mounted at the free end of the guiding rod 32, and its position is adjustable along the length of the guiding rod 32 by means of a pair of adjustment nuts 35 cooperating with a threaded free end part of the guiding rod. A pair of arms 36 form¬ ing a bifurcated end of the lever-like handle 33 are pi¬ votally connected to the slide member 30 by means of a pair of links 37, and a cross member 38 interconnecting the arms may cooperate with a stop member 39 which is adjustably mounted on the guiding rod 32 by means of a locking screw 40. The outer ends of the connecting members 23 are sur¬ rounded by and biassed towards each other by an O-ring 41 located between the closure plate 24 and the links 31.

The opening 26 in the mould wall 21 is defined by a frame member 42, and the closure plate 24 has an annular, radial¬ ly extending flange 43 for abutting engagement with the frame member 42 when the mould wall opening 26 is closed by the closure plate 24. The closure plate 24 may be held in its closing position by means of a clamping device, which is generally designated by 44, and which is fixedly mounted on the outside of the mould wall adjacent to the wall opening. The clamping device comprises a pair of L-shaped levers 45 having an adjustable abutment screw 46 at a free end and being swingably mounted about a pivot axis 47

between a pair of mounting fins 48 fastened to the outer wall of the mould 21. An actuating lever 49 comprising a handle 50 is rotatably mounted between the fins 48 so as to be swingable about a pivot axis 51. One end of the lever 49 is pivotally connected to the shorter arm of the L-lever 45 by means of a link 52, and a stop member 53 provided with an adjustable stop screw 54 is mounted on the handle 50 and may cooperate with an abutment plate 55 welded to the outer wall of the mould 21.

The clamping device 44 may be moved from its releasing position shown in solid lines in Fig. 7 to its clamping position which is indicated in dot-and-dash lines. When the handle 50 is moved to the clamping position the L-shaped levers 45 are swung by toggle action to a position in which the abutment members or abutment screws 46 are pressed against the outer surface of the closure plate 24, whereby the closure plate and the mounting device 22 fastened thereto are held in position in relation to the mould 21.

In Fig. 9 the supporting our mounting device 22 is shown in a position in which the slide member 30 has been moved away from the closure plate 24 and into abutting engagement with the stop member 39. In this position the stud-like connec¬ ting members 23 are moved substantially out of engagement with the openings 25 of the closure plate 24, and the connecting members are substantially mutually parallel as shown in Figs. 2 and 5. By moving the handle 33 from the position shown in Fig. 9 towards the position shown in Fig. 8 the slide member 30 is forced by toggle action to move towards the closure plate 24 and the mutually parallel connecting members 23 are moved into the openings 25 of the closure plate 24 till enlarged base members 23a of the connecting members 23 engage with the outer surface of the closure plate. Now, a recess plug 10 with a lifting anchor 17 mounted therein as shown in Fig. 2 may be mounted on the parallel connecting members 23 extending from the inner

side of the closure plate 24. Subsequent movement of the handle 33 to the position shown in Fig- 8 causes tilting of the connecting members 23 to the converging position shown in Fig. 7 whereby the jaws 13 of the recess plug 10 are pinched around the lifting anchor 17 and the connecting members are interlocked with the recess plug 10. By this movement the O-ring 41 is elastically expanded and the connecting members 23 are guided by diverging inner surfa¬ ces of the openings 25 in the closure plate 24.

The assembly comprising the supporting device 22 with the recess plug 10 and the lifting anchor 17 carried thereby is now arranged on the mould wall 21 so that the closure plate 24 closes the opening 26 and the recess plug 10 with the lifting anchor 17 extends into the cavity of the mould (Fig. 4) as described above. Now, the clamping device 44 may be moved from its releasing position shown in solid lines in Fig. 7 to its clamping position which is indicated in dot-dash lines in Fig. 7. When the handle 50 is moved to the clamping position the L-shaped levers 45 are swung by toggle action to a position in which the abutment members or abutment screws 46 are pressed against the outer surface of the closure plate 24, whereby the mounting device 22 and the recess plug 10 with the lifting anchor 17 carried thereby are held in position in relation to the mould wall 21.

When concrete 27 has been filled into the mould cavity, the handle 33 is moved from the position shown in Fig. 8 to the position shown in Fig. 9, whereby the stud-like connecting members 23 are swung back to their mutually parallel posi- tion and are withdrawn from the bores 16 of the recess plug 10. The plug 10 with the anchor 17 may now move freely in relation to the mould 21 as indicated in Fig. 5.

It should be understood that the separate, portable, manu¬ ally operated mounting device 22 could be replaced by an

automatic or semi-automatic power operated device, which is fixed in relation to the mould 21. Also in that case the closure plate 24 and the recess plug 10 with the lifting anchor 17 mounted therein could be positioned on the paral- lei connecting members 23 while the slide member 30 is in its retracted position corresponding to that shown in Fig. 9. Thereafter, the supporting or mounting device 22 could be moved to the position shown in Fig. 8 and the closure plate 24 could then be clamped by means of the clamping device 44 or the clamping device could be dispensed with. Similarly, the hand-operated clamping device 44 may be power operated, if desired, for example by means of a fluid cylinder.