WO1988005463A1

WO1988005463A1 - A pressing apparatus for shaping pieces of material of pasty consistency such as soap, and related process

Info

Publication number: WO1988005463A1
Application number: PCT/IT1988/000002
Authority: WO
Inventors: Aldo Mazzoni
Original assignee: Costruzioni Meccaniche G. Mazzoni S.P.A.
Priority date: 1987-01-14
Filing date: 1988-01-11
Publication date: 1988-07-28
Also published as: ES2006047A6; AU1158688A; IT8719076A0; IT1201145B

Abstract

A pressing apparatus for soap cakes having a smooth peripheral band around them comprises an intermittently rotating plate (13) equiped with compartments (11, 12) with a projecting cutting edge (16') on one face. At least one pair of dies (20, 21) cooperates with the plate, one of the dies being of such a size that it fits into a compartment, whereas the other, which is generally larger, stops at a certain distance from the cutting edge. Through holes (30) in the plate around each compartment and a cleaning element (40) with rods (33) which pass through the holes are provided for scrap elimination.

Description

"A PRESSING APPARATUS FOR SHAPING PIECES OF MATERIAL OF PASTY CONSISTENCY SUCH AS SOAP, AND RELATED PROCESS"

In order to press or stamp pieces of material having a pasty consistency, and particularly cakes of normal or synthetic soap o soap made from a mixture of normal and synthetic soap, use is made generally of machines of a known type, for example those described in Mazzoni patent No. 47588 of May 23, 1.964 or in Jones (U.S.A.) patent No. 501873 of July 9, 1930.

Cakes of soap are currently produced in various shapes. The present invention relates to cakes of soap having a shape including a smooth or flat peripheral band, joining two larger faces which are generally convex or shaped in another way.

In order to stamp cakes of soap with a peripheral flat band on the aforementioned machines, two opposing dies are used, said dies acting with a reciprocating movement to penetrate one after the other in a series of through compartments in an intermittently rotating element, designed to perform the following steps in sequence: feeding a rough piece or blank to be pressed, bringing said piece into a correct position to undergo an opposing action of the dies, holding the piece during pressing (stamping) and providing the shape of the peripheral band not affected by the dies, bringing the pressed piece or cake into a correct position for unloading onto a conveyor belt.

Usually when pressing cakes of soap with a flat peripheral band around them, during the pressing step the two opposing dies penetrate precisely for a certain length into the compartment in the rotating element, preventing escape of the material to be pressed. Thus the volume of the rough piece to be pressed must exactly coincide with the volume and thus the weight of the finished cake.

The rough piece to be stamped is usually obtained from a continuous bar produced by extrusion and automatically cut into pieces of a suitable length to be fed into the compartment of the rotating element. If the outline of the compartment, and thus of the finished cake, is formed of straight lines, for example if it is rectangular, the length and width of the parallelepipedal blank will be only slightly less than the length and width of the finished cake, while the thickness of the parallelepiped will be determined so that its volume is related with the weight of the final cake.

If, on the other hand, the peripheral outline of the compartment and thus of the finished piece, is made up of curves, for example if it is elliptical, the rough piece is preferably pre-shaped as it is fed into the compartment in the rotating element by passing it through a fixed punch or die which has a cutting edge or rim of the same shape and size as the elliptical outline of the compartment and is appropriately situated in the space between the blank feed belt and the side of the rotating element.

In this way the parallelepipedal blank, cut out from the extruded bar to a length 6 to 10 mm greater than the major axis of the elliptical-shaped punch and to a width equal to or slightly smaller than the minor axis of the elliptical punch and carried on a feed belt to the exact position in front of the elliptical punch, is pushed through said punch by a feeder-pusher and when it is subsequently fed into the elliptical compartment in the rotating element, it is of the same size or slightly smaller than the compartment itself.

Naturally scraps are formed at the two outer ends of the elliptical punch as a result of the excess length at the two ends of the blank, which is cut into an elliptical shape. The following conclusions can be drawn from the above: a) irrespective of its shape, the rough piece or blank to be pressed which is fed into the compartment of the rotating element situated level with the feeding line almost completely fills the compartment and, during the subsequent pressing stage, it undergoes the combined action of the two opposing dies which do not allow material to escape from the compartment; b) if the pressed cake of soap has a curved outline, the soap blank must be pre-shaped with the same curved shape as the outline or profile of the pressed cake, by passing the blank through a suitable fixed punch, set in front of the compartment in the rotating element, in the space between the feed conveyor belt and the side of the rotating element bearing the compartments.

Some drawbacks have been found in practical use of soap pressing (stamping) machines using the above described devices, resulting in significantly reduced machine efficiency.

In the situation described under point a), for example, the pressing machine is blocked if two soap tablets are accidentally pressed at the same time in the same compartment. This drawback occurs whenever a tablet of soap sticks to one of the two dies during pressing, instead of remaining attached to the compartment in the rotating element and proceeding to the unloading stage. In the next cycle a new blank of soap to be pressed is brought into the compartment in the rotating element and positioned between the dies, while a cake of soap which has already been pressed is still stuck to one of the two dies. As a result the two dies, as they come together, exert pressure on twice the volume of soap which, remaining trapped between the two dies and the compartment in the rotating element with no possibility of escape, causes the blockage of the press.

If the situation described under point b) occurs, the parts of the soap cut away by the punch remain stuck to the outer surface of the punch, where they gradually accumulate. If this build-up of soap is not removed by mechanical or pneumatic means, it hinders normal feeding of the blanks to the punch and, as a result, it impairs or prevents operation of the press.

An aim of the present invention is to provide an improved device to permit pressing, on two faces, of soaps having any shape but having a flat peripheral band, without the drawbacks described above.

A further aim is to produce a perfectly operating apparatus with no need for a separate punch element.

A further aim still is to produce a device that can be fed on only one side of the rotating device.

These and other aims have been achieved with an apparatus according to claim 1 and a process according to claim 6.

The new apparatus and the new process make it possible to rule out the risk of jamming due to accidental pressing of a greater volume of soap than was intended, thus increasing productivity; they make it possible to eliminate the separate punch element; they permit easy and rapid removal of scraps; lastly, they make it possible to feed rough pieces on one side only of the rotating element. The attached drawings are a schematic representation of an exemplary embodiment of the device of the present invention, and precisely:

Fig. 1 is a perspective view of the new apparatus as a whole; Fig. 2 drawn to a larger scale than fig. 1, is a horizontal section through part of the apparatus during feeding of a blank to the rotating device; Fig. 3 is a vertical section through part of the apparatus during the pressing stage; Fig. 4 is a horizontal section through part of the apparatus during unloading;

Fig. 5 is a vertical section through part of the apparatus during cleaning.

Fig. 1 is a schematic view of the new apparatus relating to an unrestrictive exemplary embodiment, capable of pressing or stamping four soap cakes at each pressing movement. This exemplary apparatus is designated by numeral 1. Apparatus 1 substantially comprises an intermittently rotating element, designated by 2, one or more feeder-puchers, designated by 9 and 10, opposing dies 20 and 21, one or more knock-out pushers, designated by 24, cooperating with unloading suckers 25, one or more cleaning elements 40.

Rough pieces or blanks 6 and 7 are fed to the apparatus by means of a conveyor belt 8 which cooperates with positioning stops 14 and 15, while a belt 26 (or a plurality of belts) carries away the pressed soap cakes S and a belt 34 conveys the processing scraps 28.

Intermittently rotating element 2 comprises a flat plate 13, made of metal or another suitable material. From the side of said plate facing feeder conveyor belt 8, box-shaped bodies or rims 16 and 17 protrude, each of which defines a compartment 11 or 12 for shaping the soap cakes.

The inner shape of each box 16 or 17 exactly reproduces the shape and size of the flat peripheral surface of each cake of soap to be produced. The edge 16' of each box facing conveyor belt 8 is a cutting edge with bevels to cut the excess part of each blank piece pushed by pushers 9 and 10 towards the inside of the box or pair of boxes. The direction of rotation of element 2, for this exemplary embodiment only, is indicated by arrow A in fig. 1.

Each pusher 9, 10 comprises a plate 9' and a shaft 9" and can move back and forth, substantially at right angles to the plane of device 2, following arrows B, for a stroke which ends at a distance d (fig. 2) from cutting edges 16' of the device.

Each first die 20 has a reciprocating movement shown by arrows C, comprises a shaped face 43 and is of an appropriate external shape and size to fit precisely into a compartment 11 of device 2; it also comprises a labyrinth 23 for circulation of a cooling liquid, to prevent the soap from sticking to the die; the die preferably also comprises a per se known ejector means 22 consisting of a plunger which slides axially in the die and is connected to a compressed air circuit.

Each second die 21 comprises a shaped face 45 and its external dimensions are preferably greater than those of compartment 11, so that part 45 cannot enter compartment 11. This die also has a cooling labyrinth 23 and an ejector 22 and can move back and forth as shown by arrows 0. The minimum distance d' between the maximum extension of die 21 and cutting edge 16' of the boxes is a few hundredths of a millimetre.

The ejectors or knock-out pushers 24 (fig. 4) consist, in the usual manner, of plates 24' which are smaller in size than compartment 11 in rotating device 2 and integral with shafts 24", as well as having a reciprocating movement along arrows E. Suction cups 25, of a per sέ known type, have a rotating movement as shown by arrows F and a downward movement as shown by arrows F' (fig. 1).

Figure 5 is an enlarged sectional view of the elements involved in the cleaning stage. A special cleaning element 40 consisting of a plate 29 attached to a reciprocating slide (not illustrated) bears projecting rods 33 of plastic material, which enter holes 30 made for this purpose around the outside of boxes 16, and two pairs of plates 31 holding a felt or rubber pad 32 the outside surface of which reproduces the internal shape of boxes 16. Ducts for compressed air jets (not illustrated) can be provided.

A description follows of the process for pressing soap cakes and operation of the apparatus.

With reference to figure 1 , blanks of soap 6 and 7 for pressing are carried on conveyor belt 8 and come from a per se known extrusion and cutting line, not shown in the figure. In the described example, blanks 6 and 7 are fed in two rows side by side and numerals 6 and 7 respectively designate blanks of one row or the other. The length of the blanks is determined so that two adjacent pressed cakes of soap are obtained from one blank, together with a certain quantity of excess soap which is expelled from the dies.

Pushers 9 and 10 push blank 7 and blank 6 into the respective pairs of comparments 11 and 12 situated in intermittently rotating element 2. The exact position of the blanks with respect to the pairs of compartments is established by stops 14 and 15 on the conveyor belt.

The stroke of pushers 9 and 10 is restricted, as previously mentioned, to a distance d from edges 16' so that the blanks are pushed only partly into boxes 16, without being cut right through by the cutting edge of the boxes. Figure 2 is an enlarged view of a single pair of boxes acting on a single blank 7, showing how the blank is partially fed into boxes 16 by the action of pusher 9.

The partial introduction of the blank into the box causes the blockage of the blank into said box, which ensures the transport to the subsequent pressing stage by a 90° rotation of the rotating element 2.

In figure 1 numerals 18 and 19 refer to the wedged blanks of soap, carried level with the pair of dies 20 and 21 for pressing.

At this stage dies 20 and 21 are brought closer to rotating element 2. With reference to figure 3, showing an enlarged sectional view of the pressing stage for a double soap cake, it can be seen that at the end of its stroke, the pair of dies 20 fits exactly into the inner compartment of box 16. The distance between the edge of die 20, when it enters the compartment of box 16 or 17 and the cutting edge 16' of said box determines the thickness of the smooth peripheral band of the pressed cake of soap.

At the end of its stroke, the pair of dies 21 stops at a distance d' of a few hundredths of a millimetre from the cutting edge of box 16, exerting the maximum pressure on the pressed cake of soap and at the same time squeezing out of boxes 16 the volume of rough soap delivered in excess with respect to the volume held in box 16.

The distance between dies 21 and the cutting edge of boxes 16 is adjusted so that the soap pressed in the box is not completely separed from the excess soap expelled from the boxes; this serves to ensure that the expelled soap is then carried to the unloading stage which follows. The next 90° rotation of rotating element 2 brings boxes 16 level with knock-out pushers 24 (figures 1 and 4) which enter the boxes pushing the pressed soap cakes out, detaching them from the excess expelled soap (scrap) 28 and causing them to adhere to suction cups or suckers 25 which, being connected to a suitable vacuum circuit, suck up the pressed soap cakes S and place them on the unloading conveyor belt or belts, after the suction cups with the soap cakes have been rotated at 90°, in the direction of arrow F, to set the soap cakes on the surface of the unloading conveyors. The unloading conveyor belts can be double or single, depending on whether the pressed soap cakes S are desired to be in two parallel rows or in one row.

Excess soap 28 ejected from the boxes remains attached to the outside surface of the boxes and a further 90° rotation of rotating element 2 carries it to the cleaning stage.

Here reciprocating rods 33 of cleaner 40 enter one after the other the corresponding holes 30 and remove the scrap from the outer rim of boxes 36, while at the same time pads 32 drag the inside surface of the box 16 and clean it, removing any remaining specks of soap. Ducts for jets of compressed air may be provided. The ejected excess soap and any specks fall onto conveyor belt 34 below, which re-cycles these scraps.

Claims

C L A I M S

1. A pressing apparatus for shaping pieces of material of pasty consistency, such as normal soaps, synthetic soaps and mixtures of the two, to obtain pressed cakes with a flat peripheral band, said apparatus comprising. an intermittently rotating element (2) equipped with through compartments (11, 12) which can be presented in a succession of operating positions as the element rotates; at least one pair of dies (20, 21) cooperating with said through compartments so that a cake of soap is pressed between them and the wall of the compartment, characterized in that on its feed side said rotating element (2) has a projecting rim (16, 17) around each of said compartments, said rim having a cutting edge (16').

2. An apparatus according to claim 1, comprising at least one reciprocating feeder-pusher (9, 10) to feed blanks of soap into the compartments (11, 12) of the rotating device, characterized in that the closest position of the feeder-pusher to the rotating element is at an appreciable distance from the cutting edges (16') of said rotating element.

3. An apparatus according to claim 1, said pair of dies (20, 21) comprising a first and a second die which move forwards and away with respect to the rotating device, characterized in that said first die (20) has a part of such a size as to fit tightly into a said compartment and said second die (21) has a stroke which ends at a minimal but not null distance from the cutting edge of the rotating device.

4. An apparatus according to claim 1 , characterized in that the rotating element has through holes (30) around the rim, said apparatus also comprising cleaning elements (40) which cooperate with said holes, said cleaning elements being carried on a reciprocating element and comprising small rods (33) which pass through said holes (30).

5. An apparatus according to claim 4, characterized in that the cleaning elements comprise ducts for jets of compressed air.

6. A process for shaping pieces of material of pasty consistency, such as soaps with a flat peripheral band, starting from cut blanks, on a shaping apparatus with a rotating device having through compartments with a cutting edge, characterized in that it comprises the following stages: - pre-cutting the blanks (6, 7) to a size at least slightly larger than the dimensions of a compartment (11, 12);

- pushing each blank against the edge of one or more compartments by means of a pusher (9, 10) ; - stopping the pusher at substantial distance from the cutting edge so that the blank remains wedged in the cutting edge;

- shaping a cake of soap (S) by means of two opposing dies (20, 21), of which only one enters the compartment, while a small but not null gap is left between the other and the cutting edge of the compartment;

- detaching each pressed cake of soap from its scrap (28) by means of an ejector element (24) which pushes the soap out of the compartment.

7. A process according to claim 6, characterized in that it comprises the further stage of eliminating the scrap (28) which remains attached to the cutting edge.

8. A process according to claim 6, characterized in that the length of the blanks of soap to be pressed is calculated so that one cake of soap can be obtained from a single blank, or two or three or more cakes of soap can be obtained at the same time from a single blank, or two cakes of soap can be obtained from two separate blanks, or four or more cakes from two separate blanks.

9. A process according to claim 6, characterized in that the blanks are fed on only one side of the rotating device.

10. Apparatus and process according to what is described herein and illustrated in the attached drawings.