The present invention relates to a block stone moulding machine and a mould system therefor. For pro¬ ducing block stones with different shapes in such a machine use is made of mould systems consisting of mould frames with respective, particularly shaped moulding cells and associated compacting heads in the form of a plate with downwardly projecting, rigid pressing foot portions having lower, horizontal press plates matching the shape of the moulding cells, such that all these press plates can be moved down into the moulding cells at the same time. The mould frame is placed on a mould¬ ing surface, and for each operation concrete mass is filled into all the moulding cells by means of a con¬ crete charged filler cart or the like, which is dis¬ placed over the top side of the mould frame and re¬ tracted therefrom, whereafter the compacting head is lowered from a raised position for pressing the press plates against the concrete mass in each of the moulding cells, while the mould is vibrate ¹ . Hereby the concrete mass is compacted. When the desired product height has been achieved the compacting head is arrested in its lower position and the mould frame is pushed upwardly, such that the moulded block stone members are left free¬ ly standing, and finally also the compacting head is raised from its holding engagement with these members, whereafter the stone members with the associated mould¬ ing plate are automatically removed from the production area. The mould frame is lowered into its working posi¬ tion on the moulding plane, and a new working cycle can be initiated.

The means for anchoring and vertically moving the

mould frame should be mounted and controlled with high accuracy relatively to the means carrying the compacting head, such that by the lowering of the compacting head the press plates thereof will pass down into the mould¬ ing cells without hitting the top edges of the cells. Often the clearance between the outer edges of the press plates BAOand the surrounding walls of the moulding cells should be only some 0.5 mm, and the tolerance of the associated guiding should be still much finer.

The relevant holding means are constituted by heavy machine parts, which can well be held and guided with a high mutual accuracy. The rest, then, will be a question of the mould parts being secured to the holding means with the same high accuracy, and here it is important that different sets of mould systems should be mount- able, such that it is not sufficient to arrange for an accurate mounting once and for all.

The mould frame is suitably made with laterally protruding flanges having accurately placed holes for receiving spanner means on the associated, guided rais¬ ing and lowering means, while the compacting head is secured to an overlying carrier head, which is mounted and guided just as accurately relatively to the holding means of the mould frame. Traditionally, this carrier head is provided with accurately positioned holes for receiving clamp bolts for the fixation of the top plate of the compaction head, this top plate correspondingly being provided with accurately positioned bolts or bolt holes, such that the desired result will be obtained when both the mould frame and the compaction head are fastened by bolting, with the use of the already pre¬ pared bolt holes.

In practice, however, this implies two significant problems, viz. that it is a difficult and time consuming work to carry out the fixation of the compacting head on the carrier head, and that the bolts or bolt holes of

the compacting head shall have to be positioned with the said high accuracy.

It is the purpose of the present invention to pro¬ vide an arrangement, with which these problems are mini¬ mized.

According to the invention the holding means of the carrier head are constituted by depending, upwardly tightenable gripping members, which are profiled so as to be able to receive correspondingly profiled, upstand¬ ing engagement members at the top side of the compacting head, such that the compacting head can be mounted on the carrier head by a horizontal insertion movement and a subsequent tightening up of the gripping members of the carrier head for effectively anchoring clamping the engagement members of the compacting head. This inser¬ tion is effected with the compacting head in engagement with the mould frame and with the press plates centered in the moulding cells, viz. by a premounting of distance pieces between selected edge portions of the press plates and the adjacent wall portions of the respective moulding cells. The insertion of the mould frame with the compacting head already mounted therein is effected until the mould frame assumes its position for being fixed to the complementary holding means of the machine, whereafter this fixation is worked out, whereby the entire mould system is secured in a reference position relatively to the machine. At the same time the engage¬ ment members of the compacting head will be brought into a 'floating' engagement position relative to the grip¬ ping means of the carrier head, and when the gripping means are thereafter actuated for fixation of this posi¬ tion of engagement it will be achieved that the compact¬ ing head is automatically secured to the machine in a correct position relatively to the mould frame. There¬ after the said distance pieces in the mould frame can be removed, and the machine can be taken in use.

Just because of the 'floating' engagement between the carrier head and the compacting head as hereby made possible it is also made possible to neglect qualified tolerance requirements for the positioning of the an¬ choring means, since an accurate positioning will be obtained anyway, namely due to the temporarily estab¬ lished primary centering of the compacting head rela¬ tively to the mould frame and the primary orientation of the mould frame relatively to the machine, and already the elimination of these requirements will be an impor¬ tant advantage.

However, the invention provides for an additional important possibility, viz. that of the compacting head being secured to the carrier head automatically, without the troublesome use of the spanner bolts as used herein¬ before. With the invention no bolt tightening is to be effected, but just a pulling up of the said gripping members, and such a pulling up may be effected in an easy manner by means of one or more working cylinders or correspondingly simple moving and holding means. Such cylinders may well be placed and perform tightening operations at manually not easily accessible places, and it is thus an attractive result of the invention that the centered fastening of the compacting head can be effected in a quite simple manner at suitable places, also where these would not be easily accessible.

Moreover, the consumption of time for changing out a mould system will be reduced considerably, whereby the production can be increased, and the better and safer centering of the press plates in the mould cells will reduce the wear on the mould.

In the following the invention is described in more detail with reference to the drawing, in which:-

Fig. 1 is a perspective view of parts of a block stone machine and a mould system adapted therefor,

Fig. 2 is a lateral view thereof, and

Figs. 3 and 4 are detailed views of a fastening arrangement.

In the left side of Fig. 1 a couple of main parts of a block stone machine is indicated, viz. carrier means 2 for holding a mould frame above a moulding table 4 and an upper carrier head 6 for an underlying compact¬ ing head for cooperation with the mould frame. In the right hand side an associated mould system is illu¬ strated, consisting of a lower mould frame 8 having throughgoing moulding cells and an upper compaction head 12 provided with depending pressing foot portions 14, which project down into the moulding cells and are pro¬ vided with lowermost, transverse press plates 16 shaped according to the cross sectional shape of the moulding cells and being only slightly smaller than that. The compacting head has a top plate 18, to which the foot portions 14 are secured by welding, and the mould frame 8is provided with laterally projecting flanges 20 having bolt holes 22.

The carrier means for the mould frame 8 are con¬ stituted by opposed, horizontal carrier pieces 24 oper¬ able to support the flanges 20 of the mould frame and having bolting holes 26 for cooperation with the holes 22, such that the mould frame 8 may be anchored in a conventional manner with a highly accurate positioning relatively to the moulding machine, despite that in connection with the invention it is not so important that this accuracy by particularly high. The carrier pieces 24 are mounted in a vertically movable manner in the machine, here illustrated by the the use of an underlying, vertical working cylinder 28. Conventional¬ ly, corresponding bolt holes 30 and 32 could be provided in the lower flange portions 34 of the carrier head 6 and in the top plate 18 of the compacting head 12, but in connection with the invention such holes are not used. On the other hand, the invention is of a character

such that these holes may well be present, inasfar as the invention can be exploited by simple additions to already consisting machine and mould parts.

According to the invention there is. mounted on the top side of the top plate 18 of the compacting head some lying C-profiled holding members 44, which are open upwardly and in the length direction forwardly towards the carrier head 6. On this head there is corresponding¬ ly mounted some holding pieces 46 rigidly secured to the lower ends of piston rods depending from respective, rigidly secured working cylinders 48. When these holding pieces 46 assume a lowered free position they will be operable to freely receive the inserted holding members 44 as illustrated in Fig. 3. This insertion is effected by the mould system 8,12 as shown in Fig. 2 being placed on a carriage 50, which, on a conveyor surface 52 in front of the moulding plate 4, is moved onto this plate with the carrier head adjusted to such a height position that the lower holding pieces 46 are situated just in level with inner recesses of the C-profiled members 44, i.e. the latter can freely be driven into respective positions in which they are entirely loosely engaging the holding pieces 46. In this inserted position of the mould system 8,12 there is effected an anchoring of the mould frame 8 to the carrier pieces 24, these being raised to the relevant mounting level. Hereby the posi¬ tioning of the mould frame in the moulding machine will be determined.

It is important to notice that before the intro¬ duction of the cart 50 the compaction head 12 has been centered relatively to the mould frame by means of distance pieces 52, which are mounted between edge areas of some of the press plates 16 and the adjacent wall portions of the moulding cells 10, whereby a correct mutual positioning of the mould frame 8 and the compact¬ ing head 12 will be ensured in a direct manner, i.e. not

indirectly as if based on the use of the bolt holes 30 and 32.

When the mould system 8,12 has been brought into position and the mould frame secured to the carrier pieces 24 the cylinders 48 are actuated for pulling up the holding pieces 46, whereby these, as shown in Fig. 4, will clamp the upper profile flanges 54 of the C-profiled holding members 44 upwardly against the lower side of the lower flanges 34 of the carrier head 6, such that hereby the entire compacting head 12 will be fixed the the carrier head in a correctly centered position relative to the the mould frame. In the profile members 44 there is a certain clearance for the holding pieces 46 in both the longitudinal and the cross direction, such that the tolerance requirements will here be very low.

Once the compacting head 12 has thus been secured by clamping to the carrier head the distance pieces 52 can be removed, whereafter these parts 12 an 6 are free¬ ly displaceable in the vertical direction, with a main¬ tained accurate mutual centering in the horizontal plane. The mould frame 18 can be lifted slightly, so as to get free of the cart 50, whereafter the cart can be removed from the area. Then the mould frame 8 is lowered to rest on the moulding table 4 , and the compacting head 12 can be raised until there is sufficient room for the introduction of the said filler cart or frame for sup¬ plying concrete mass to the mould frame 8.

Thereafter the moulding machine can operate fully conventionally, the compacting head 12 being lowered for compacting the concrete mass in the single moulding cells 10 and later being arrested for pressing down the moulded stone members towards the moulding table 4 while the mould frame 8 is moved upwardly from the moulded stone members for liberating these to be delivered out¬ wardly along the conveyor path 53, Fig. 2.

The invention is of course not restricted to the illustrated arrangement, in which the carrier head 6 is provided with upwardly retractable holding pieces 46, since, by way of example, it would be equally well pos¬ sible to make use of upwardly retractable profiled hold¬ ing portions cooperating with upstanding, rigid holding head portions on the compacting head 12.

It is not strictly necessary to modify the carrier head 6 by adding the parts 48,46, as these parts might be provided on a separate carrier plate that can be fastened to the carrier head by bolting, using the bolt holes 30. This will even make possible that the carrier head can be used alternatively in a conventional manner, which might be desirable in certain situations that should not here be described in more detail.

It may occur that it is desired to introduce distance means between the underside of the carrier head 6 and the top side of the compacting head 12, but in connection with the invention this will be perfectly possible, e.g. by securing to the compacting head 12 by means of the bolt holes 32 an upstanding structure hav¬ ing upper holding rails or members corresponding to the profiled members 44.

It is to be emphasized that the invention provides for the special advantage that in a relatively simple manner the invention can be realized also in connection with already existing moulding machines, namely with only the discussed modifications of the carrier head and the compacting heads 12, respectively.