The invention relates to a device for manufacturing mouldings of clay or such material, as defined in the preamble of claim 1.

Such a device is disclosed in Eλitch patent 161.832. With this well-known device the press is operating in a continuous manner, while the iiraulding tray is inteαήttently displaced. Each moiilding tray comprises a number of moulding cavities, some of which, usually two, are filled by the same press.

In case of a breakdown necessitating the device to be switched off, problems are encountered. Immediately upon switching off or shortly after the device being put into operation again following a breakdown, pieces of clay may get at an incorrect location in or on the moulding tray. This leads to the situation that not all of the moulding cavities of some of the moulding trays are correctly filled and/or that a second piece of clay is deposited on top of a piece of clay which has already been dropped into a iioulding cavity. Moulding trays, with which such phenomenons have occurred cannot be processed any further, so that in case of a breakdown loss of production as a result of the problem indicated is taking place in addition to the loss of production caused by mac± ne standstill. The invention aims at providing a device of the type above referred to, with which these objections do not exist.

With a device according to the present invention this aim is achieved by the measure mentioned in the characteristic clause of claim l. In case of a breakdown the said obstruction means are moved into their operative position, due to which the ribbon of clay is blocked.

A piece of clay breaking off from the ribbon by force of gravitation, is now prevented from falling in an uncontrolled manner into the direction of transportation and is thus prevented from getting into or onto a moulding tray in an uncontrolled manner as well. Upon removal of the breakdown and putting the device into operation again, the obstruction means are returned into the rest position, so that the device is allowed to operate in the usual manner. The obstruction means effectively avoid additional loss of production by moulding trays which have been incorrectly filled as a result of a breakdown.

A particularly useful embodiment of the device according to the invention is characterized in claim 2. With brick moulding devices according to the prior art guide rollers per se are used to ensure

that ^" the pieces of clay will get in the right position in the direction of transportation or the depositing device. For the cutting device is usually operating with a cutting wire which is pulled through the ribbon transversally to the longitudinal direction of the ribbon. As a result of this movement the cut piece of clay may be subjected to a lateral displacement, which is corrected by the guide rollers. Ey mounting at least one of said guide rollers in such a way, that it may be moved in a position under the ribbon, the desired obstructing ef ect may be achieved in a favourable manner without many additional parts being required.

Preferably the feature of claim 3 is applied with this embodiment.

Especially when use is made of the feature of claim 4, due to which all of the guide rollers functioning as obstruction means are simultaneously placed in the operative obstruction position within a usual multiple brick moulding machine, a simple and reliable construction may be obtained.

For ensuring a correct controlling of the obstruction means the feature of claim 5 is to be preferred. As soon as the device is switched off, the control device will automatically place the obstruction means into the operative position.

Ey means of the feature of claim 6 it is achieved that the obstruction means are returned into the rest position only after the device , and in particular the transportation of the moulding trays of it, has reached the normal speed. This avoids even the small chance that a piece of clay iπight be delivered untidy.

For an accurate working, which may be dependent of the further properties of the device and of the type of clay material used, the feature of claim 7 is to be preferred. A simple embodiment is achieved by means of the feature of claim 8.

The invention will be hereinafter further explained by reference to the embodiments shown by way of example in the accompanying drawings.

Fig. 1 is a partially sectional perspective view of the device -acxxirding to the invention in a preferred embodiment, only that part of the device being shown which is relevant for a good urderstanding of the present invention.

Fig. 2 is a similar view, relating more in detail to the obstruction means of the device of Fig. 1.

In Fig. 1 there is shown a part of a device 1 for producing mouldings of clay or similar material. A plurality of such parts may be placed side by side in one device 1 and operate simultaneously for filling clay into moulding trays. The device 1 thus comprise at least one press 2, adapted to deliver a ribbon 5 of clay (indicated by dotted lines) which is expelled downwardly through a press nozzle 4. The press also comprises a supply bin (not shown) from which the clay material is pressed towards the press nozzle 4 by means of a shaft with blades 3. Under the press nozzle 4 a sanding device 6 is provided. The sanding device 6 comprises a sand pan 7 surrourκ±Lng the ribbon 5. Sand may be supplied to the sand pan 7 from a main screw conveyor 8 through a supply screw conveyor 9. A metering device 10 supplies the sand in the desired amounts into the main conveyor 8. In case a plurality of the units shown in Fig. 1 are incor¬ porated in one device, as herebefore remarked, the supply conveyors 9 of each sanding device are all connected to the main conveyor 8.

The sand supply into the sand pan 7 is pressed against the sides of the ribbon 5 by means of blades 11. In order to have the blades 11 carry out the desired pressure movement they are each provided at the end of a rockingly driven shaft

12. The shafts 12 are journalled in a disc 13 which is rotatably mounted about the axis of the press 2, said disc being rotated by means of a drive mechanism 14. Actuating arms 16 are fixedly connected to the shafts 12 and carry a cam follower 17 at their free end. The cam follower 17 is kept, by spring action, in contact with a cam 15 which is fixedly connected with the device. It will be appreciated that the cam 15 has a suitable non-circular shape, so that rotation of the disc and consequently of the shafts 12 around the cam 15 will cause the cam followers 17, which are in spring contact with the cam

15, to move inwardly and outwardly in a regular manner. The latter movement is transferred, through the actuating arm 16 and the shaft

12, to the respective blade 11, so that the latter, while performing a rotational movement, will s-Lmultaneously perform the desired pressing movement and thereby press the sand against the sides of the ribbon 5.

A membrane assembly 18 is provided in the bottom of the sand pan

7 and has a suitably shaped passage opening. The ribbon 5 is moving through the latter opening, whereby the sand is pressed into the surface of the ribbon 5 by means of the edges of the resilient

membrane assembly 18. The membrane assembly is mounted in a removable cassette, so that for particular circumstances a suitable membrane assembly 18 may be used.

Under the sanding device 6 an assembly of four pressure rollers 20 is provided which is adapted to further press the sand adhering to the ribbon 5 and to catch loose sand moving along with the ribbon through the passage opening and press such sand also into the ribbon.

By means of a cutting device which is synchronized with the further parts of the device and in particular with the conveyance of the moulding trays 40 to be described hereinafter, pieces of clay are cut from the sanded ribbon of clay 5. The cutting device performing this function comprises a cutting frame 25 which is guided by means of rollers 26 and is mounted for a reciprocating movement within the framework. The reciprocating movement is effected by a cylinder device 27. A cutting wire 28 is stretched in the cutting frame 25. In case of a device comprising a number of press and depositing units one ∞mmon cutting frame 25 may be provided, in which all of the cutting wires are mounted. The working is such that during each extension of the cylinder 27 a piece of clay is cut from each ribbon supplied by each press and the same procedure is taking place during each retraction. Between each retraction and extension of the cylinder 27 the cutting device is in a rest position for some time.

Guide rollers 30 and 31 are mounted under the cutting device. The guide roller.30 shown in Fig. 1 is fixedly joumalled onto the framework of the device 1, while the guide roller 31 is joumalled onto a sliding frame 32 which may be displaced by means of a cylinder 33. Daring normal operation of the device 1 the sliding frame 32 with the roller 31 is taking a position displaced to the left as compared with that of Fig. 1, in which the roller 31 is spaced from the roller 30 to such an extent, that the cut piece of clay may readily pass therebetween. In this stage of the procedure the guide rollers 30 and 31 ensure that the cut piece of clay, which might be given a certain lateral movement due to the movement of the cutting wire, will be brought in the correct position above the depositing device 35. In the position of the sliding frame 32 shown in Fig. 1 the guide roller 31 is kept within the path of the ribbon of clay 5. In a rest position of the device 1 the guide roller 31 is kept in this position in order to avoid that pieces which have become separated from the ribbon 5 could get into the depositing device 35 or might

pass through the latter onto the moulding tray 40 in an uncontrolled manner.

The depositing device 35 comprises the set of two juxtaposed pairs of a drive roller 36 and an underlying idle roller 37, a belt 34 being trained around each pair of rollers 36, 37. The rollers 36 are driven such, that the mutually facing runs of the belts 34 between the drive rollers 36 and the idle rollers 37, are both moving downwards. A piece of clay 38 supplied from above will thus be taken between the belts 34 and driven downwardly at a certain depositing speed. As a result of this the clay 38 will be thrown into the moulding cavity 39, allowing the clay to spread a little so that the moulding cavity 39 of the moulding tray 40 will be completely filled. It is to be remarked that in general the deposited piece of clay 38 will have a larger volume than the moulding cavity 39, and that the excess of clay will contribute to a complete filling of the moulding cavity 39. The excess of clay is removed in a later stage of the procedure.

As remarked before, a device of this 'type may comprise a number of the press and depositing units described so far. As an example such a device may comprise two rows of three units, said rows being mutually offset through half the spacing between two adjacent units.

With such a sixfold device moulding trays 40 having twelve moulding cavities 39 may be filled in four steps. The mutual spacing of the moulding cavities in a moulding tray will preferably correspond with a quarter of the spacing between two units in a row. In the first step the moulding tray may e.g. be positioned such that the moulding cavities of the order 1, 5 and 9 are being filled by the units of the first row. The moulding tray will then be displaced in longitudinal direction through a distance which is equal to the spacing between two moulding cavities, so that the itioulding cavities of the order 2, 6 and 10 will then be filled.

For the third step the moulding tray is displaced in transversal direction until under the second row of units, whereby, as a result of the offset position of this second row relative to the first row, the moulding cavities of the order 4, 8 and 12 will get positioned under the respective units and filled by the same. At last the moulding tray is returned in the longitudinal direction through a distance corres¬ ponding to the spacing between two moulding cavities in the moulding tray, so as to have the last three moulding cavities, viz. thos of the order 3, 7 and 11 filled.

It will be appreciated that the moulding tray conveyance is controlled in such a way, that at each time a moulding tray will be positioned under each row of units.

The loaded moulding trays 40 are discharged, by a conveyor not shown, to a device in which the excess of clay is removed. Thereafter the mouldings will be transferred, in an inverting device, onto a drying shelf for further processing. This further processing will generally comprise the steps of drying and firing, so that fired products such as bricks or tiles will be formed from the mouldings. As shown in more detail in Fig. 2 the guide roller 30 is jou alled in brackets 45 which are fixedly connected with the frame. In the brackets 45 slots 46 are provided permitting the shaft bearing 44 to be transversally adjustably connected by means of screw 47. The guide roller 30 can be adjusted such that it will just contact the right-hand side of the ribbon 5 (vide Fig. 2) or of the piece 38 separated therefrom.

The guide roller 31 which constitutes the obstruction means accxDrding to the invention serving to block the ribbon of clay 5, may be adjusted in a similar way by means of slots 51 and screws 52 provided in brackets 50 on the sliding frame 32. The sliding frame 32 carries, at its left-hand end shown in the drawing, two sliding rods 49, which slidingly pass through brackets 48. On the right-hand side (not shown) the sliding frame is guided in a similar way. m case of a multiple decive, comprising a plurality of press and depositing units, one ∞mmon sliding frame is provided for all of the units positioned in one row. For each unit the left-hand guide roller 31 is mounted on -the sliding frame 32.

Under normal operational conditions of the device of the present invention the sliding frame 32 is taking the left-hand end position indicated by dotted lines. In this position the guide roller 31 is taking a position in which it is just contacting the side of the ribbon of clay 5 or of the piece of clay 38 separated therefrom, in a similar manner as is the case with guide roller 30.

As soon as the device is switched off in connection with a breakdown at any location, the cylinder 33 will be immediately activated to move the sliding frame 32 to the right into the position shown in the drawing. This places the guide roller 31 into the path of the ribbon of clay 5, so that, if, e.g. during a standstill of the machine a piece of clay gets separated from the ribbon 5, such piece

is caught by the roller 31 and is thus prevented from dropping into the depositing device 35 or, while passing therethrough, into the moulding tray 40.

In the embodiment shown in the drawing the cylinder 33 is a pneumatic cylinder; the air supply for activating said cylinder 33 for returning the sliding frame 32 to the left is adjustable, so that the returning movement will be started after a certain delay upon switching the air supply on. During this delay time the device and more particular the moulding tray transporation may reach the normal speed, so that, as soon as the guide roller 31 fuiictioning as obstruction element has been displaced out of the path of the ribbon 5, an empty moulding cavity 39 will have been positioned under the depositing device 35.

The embodiment of the present invention described hereinbefore is to be preferred, because it enables an element already present to be used in a simple manner as the obstructing means according to the invention. It will, however, be clear that the obstructing means may be performed in various ways and e.g. may comprise elements which are exclusively provided for the purpose aimed at and which are movable from a position beyond the path of the pieces of clay into a position within the path and under the cutting device.