The present invention concerns a molding apparatus for shaping pieces of soft and pasty substances, such as normal, extra grease and synthetic soaps, their mixtures and similar substances.

Soap molding machines of the most common type presently on the market 5. include an element called a disk or star or star-disk rotating on an axis set at right angle with respect to the direction of travel of the soap on feeder and discharge conveyor belts. This type of equipment, called "rotating disk machine", does not allow that a large number of molds be mounted because if the number of molds is 10. increased, the disk diameter also increases and the resulting inertial forces cause severe mechanical and process problems. With such machines the production can be increased by increasing the speed while maintaining a constant number of molds and therefore they can be defined as "fast" type machines.

15. There is also another type of apparatus, less common, which includes

an element, called a rotor, which rotates with a rotation axis parallel to the direction of travel of the soap on the feeder and discharge conveyor belts. Machines of this type, that could be called "rotor machines", allow a theoretically unlimited number of molds to 5. be mounted along the major rotor axis; in practice, given the present state of the art, such machines are equipped with eight molds at the most, mounted on one or two rotors . These machines can thus increase production by increasing the number of molds while operating at constant speed and they are therefore called "slow" type machines.

10 ^• The machine speed in terms of strokes per minute is presently about 100-150 on the "fast" or disk type machines and 50-60 for the "slow" or "rotor" type machines, depending on the model.

Known molding machines, of the slow or rotor ty e, are subject to a series of disadvantages and problems. If 180° rotor rotation is

15- envisaged, it will be difficult to keep the molded piece on the rotor, since the high centrifugal force developed by the high rotor speed pulls the soap off the mold. Those types of equipments where the pieces to be shaped are delivered by means of arms mounting suction cups or other cumbersome feeder units, require a long

20. displacement of the translating half-molds to allow enough space for the insertion of said feeder units; to travel the additional distance, the half-molds will also have to travel very quickly. In addition, feeder units increase manufacturing and operating costs.

In those machines where for each piece to be mold two half-molds are

25. foreseen facing each other, at 180° on the same rotor, there is a total of three half-molds for each piece to be molded: two for feeding and molding and one for discharging and cleaning. This

increases operating costs of the molding machine.

The rotor carrying the half-molds must be cooled with an appropriate coolant. The use of a vacuum device to hold the soap in the rotational/translation phase is also normally required, as well as 5. that of compressed air to expell it during the discharging phase. In those machines where the rotor always rotates in the same direction, fluid sealing problems will also arise.

From the Japanese publication No. JP-A-58 160 108 a molding machine for plastic material is known, in which the mold and countermold are 10. capable of a rotating motion and a reciprocating linear motion.

The aim of the present invention is to improve molding machines of the "rotor" type, in particular machines for molding soap pieces or the like, so that the above problems can be avoided.

This object has been reached by providing an apparatus that includes 15. at least three rotors having parallel axes, the two lateral rotors having a rotating/translating motion, so that when they reach the central rotor moving in a radial direction, they shape the product, then they move away with the molded piece and deposit it on the discharge conveyor belt by effecting a 90° rotation alternately with 20. respect to each other, while the central rotor, equipped with two half-molds rotates by 90° and moves alternately one or the other half-mold in front of each one of the two lateral rotors while discharging excess molding product from the one of said half-molds which is not molding a piece of soap.

The apparatus, according to the instant invention, includes in Its. simplest form, a central rotor equipped with two half-molds placed at 90° and capable of a reciprocating rotating motion and two lateral rotors, placed on the opposite sides of the central rotor, capable of

5. a reciprocating rotating translating motion, each supporting a half-mold, the rotors having their axis of rotation parallel to the conveyor belts.

Preferably the apparatus comprises elevators/lifting devices mounted between the rotors which raise the bars to be molded up to the height 10. of the mold.

Preferably in the apparatus according to the invention in the half-mold carrying the molded piece, the vacuum is created by means of flexible tubes so as to hold said piece.

The apparatus according to the invention can have any desidered 15- number of molds placed longitudinally along each rotor so that it can mold two, three, four e.tc. pieces at each translation of each lateral rotor.

The rotors can also be of greater number and have complex movements for solving particular feeding problems of the product.

20. An apparatus according to the invention, without any cumbersome feeding units , has the additional advantage of requiring only a short rotor translation motion during molding operation. The alternate rotor rotation at only 90° has as an advantage the fact that the molded piece is easily held on the rotor itself. For this same

reason, coolants and compressed air, as well as the vacuum can be fed to the mold with simple flexible tubes in the mold. This is not possible with known rotor systems that rotate in the same direction and where rotating seals and complex constructive devices are 5. necessary.

The present invention will be now better described on the basis of exemples of embodiments illustrated in the accompanying drawings, in which:

Figs, la, lb, lc, Id, and If schematically show a molding machine 10. comprising three rotors in various subsequent working positions.

Fig. 2 show an axonome ric view of a first embodiment of the invention;

Fig. 3 shows an axonometric view of a second embodiment;

Fig. 4 shows an axonometric view of a third embodiment.

15. Figures la, lb, lc, Id, and If schematically show a soap molding apparatus during various production phases. This apparatus comprises a first ..rotor 1, capable of a reciprocating rotating/translating motion, having in a section of its periphery a half-mold 3. A second rotor 2 having two half-molds 4 and 4' on its periphery at 90° one

20. from the other is placed near the rotor 1, at a certain distance therefrom. Near the rotor 2, but opposite to rotor 1, another rotor 1', similar to the first one, is placed, supporting a half-mold 3'. Under each rotor 1 and l ¹ a conveyor belt 6 and 6' respectively is placed and under rotor 2 another conveyor belt 8 is placed. In the

25. open space between the rotors 1 and 2, l ¹ and 2' respectively, conveyors belts 7 and 7' respectively are visible as well as

elevators 5 and 5' respectively, each supporting a bar of soap 9, 9'.

The operating cycle of this apparatus described hereunder, with reference to the only couple of rotors 1 and 2, taking Into consideration that the molding occurs alternatively between rotor 1 5. and rotor 2 (figg. la and lb) and between rotor 1' and 2 (figg. Id and le) . While a lateral rotor is molding the other rotor rotates so as to discharge the molded piece and vice versa.

The soap piece 9, already cut and ready to be molded is carried on feeder belt 7 to the elevator/lifting device 5, which lifts it

10. between the half-molds 3 and 4 (fig. la). At this point, rotor 1 approaches rotor 2 and piece 9 is positioned in the half-molds 3 and 4, while lift 5 is lowered and ready to receive immediately a piece 9 for molding (fig. lb) . While it is being molded, excess soap 11 exits from the mold. When the pressing action is terminated, rotor 1 moves

15. away (fig. Ic) and rotates (fig. Id and le) and deposits the molded piece 10 on the discharge conveyor belt 6 (fig. le) ; rotor 2 rotates (fig. lc) in opposite direction with respect to rotor 1 and deposits excess soap 11 on the discharge conveyor belt 8 (fig. le) . The molded piece 10 is held in half-mold 3 during the rotation/translation

20. return motion of rotor 1 by a vacuum; during the releasing phase the vacuum is cut off and compressed air is blown into the mold to allow the release of the soap from the mold. Excess soap 11 can be held on the outside of half-mold 4 during rotation of rotor 2 by known anchoring means, not included In this invention. Rotors 1 and 2

25. rotate in the opposite direction to the previous one (fig. If) and reach the position shown in fig. la so as to be able to receive a new piece 9 to be molded.

The half-molds 3, 3', 4 and 4' are cooled by means of flexible tubes (not shown) , which in addition to the coolant, also delivers to molds 3 and 3' the air necessary for releasing the pieces and the vacuum to keep them in the mold. As the rotors move with reciprocating motion 5. the air and coulant feeding can be carried out by means of tubes without rotating connectors.

Fig. 2 shows an apparatus, having an operating system as shown in figures la to If, which is foreseen for molding two pieces of soap at each translating motion of each lateral rotor, as soap bars 19 and 10. 19' are pre-cut to such a length as to allow two pieces of soap to be molded. Each of them produces two pieces of soap 10 and two pieces 10' as well as excess soap 21 and 21' respectively, which is the double with respect to the excess soap 11 and 11'.

Fig. 3 shows an apparatus made up of two units A and B of three

15. rotors disposed one right after the other so that each rotor of one unit is coaxial with the corresponding rotor of the other unit. Each unit operates, if taken singly, like the apparatus shown in fig. 2.

The two units are synchronized with each other in such a way that when the first unit A is molding with the lateral rotor 1, placed on

20. the right in the illustration, the second unit B is molding with the lateral rotor l ¹ placed on the left in the illustration and vice versa. There are two feeder belts, 7 and 7', common both to the first unit A of three rotors and the second unit B. In a similar way discharge belts 6 and 6' of molded pieces and belt 8 for excess soap

25. 21 and 21' are common to both units A and B.

Fig. 4 shows an apparatus operating as shown in figures la to If.

This apparatus is foreseen for molding four pieces of soap at each translation of rotors 1", I" ¹ and 2". To this purpose blank soap bars

29 and 29' are fed on belts 7 and 7'; said bars 29 and 29' are of such a length to be used to form four pieces 10 and four pieces 10',

5. that are removed by means of belts 6 and 6' respectively. Excess soap 31 and 31' is removed by belt 8.

In the attached figures, arrows Indicate the direction of travel of each element.