Automatic molding press adapted for making molded pieces from an extruded continuous strand of soap and the like materials

Abstract

 The present invention has for its object an automatic molding press which is adapted for molding finished pieces (P) from an extruded continuous strand (B) of a plastic material, such as a solid soap, a paraffin wax, and the like, characterized in that it comprises means (2) for conveying the extruded strand (B) along a horizontal path length, in correspondence of which molding means (3, 4) are arranged, which are adapted for acting in a horizontal direction upon the strand (B), transversely thereto, so as to make finished pieces (P) therefrom, to be taken up by underlying unloading means (14).

Description

[0001] The present invention concerns the automatic molding presses that are adapted for molding finished pieces from an extruded continuous strand of a plastic material, such as a solid soap, a paraffin wax, and the like.

[0002] A molding press of this kind is described and shown in a former Patent Application of the same Patentee. In the said molding press the extruded strand is led along a substantially horizontal path length, where it is cyclically engaged by vertically operated molding means which make from the strand the finished single pieces, while leaving there= around a continuous strip of waste material. Typically, between the molded pieces and the relative waste material a thin connecting burr is purposely left, which allows the continuous waste material itself to withdraw the molded pieces from the molding means and to take them away there= from. Then, the molded pieces are separated from the waste material with or without the aid of separating means, by guiding these pieces and the waste material in diverging directions. Since the said molding press is provided with sensing means that conform its operative speed to the output speed of the strand-extruding means, it is capable to mold the pieces directly from the strand issuing from the extruding means, while the conventional similar molding presses must first cut the strand into sections of a proper length, and then feed these sections to the molding means.

[0003] The molding press that has been briefly described above, affords sure advantages, such as a simple construction and a good standard of production, but since it leaves a continuous strip of waste material, it requires special contrivances for unloading the said waste material, which sometimes are complex in construction.

[0004] This problem is entirely overcome by the present invention that, for this purpose, proposes an automatic molding press of the type initially mentioned, in which means are provided for conveying the extruded strand along a horizontal path length, in correspondence of which molding means are arranged, which are adapted for acting in a horizontal direction upon the strand, transversely thereto, so as to make therefrom finished pieces to be taken up by underlying unloading means.

[0005] In one preferred embodiment of the molding press according to the invention, the said means for conveying the extruded strand comprise two facingly arranged horizontal ribbons between which the extruded strand is engaged, where= by the end of the strand can be stepwise moved forward between two opposite molding members, preferably consisting of a mold which is imparted a reciprocating motion, and of a relative matrix, or box, with a movable bottom; under the said molding members an unloading ribbon is provided, onto which the just finished piece is caused to drop.

[0006] These and other features of the molding press according to the invention and the advantages arising there= from will clearly appear in the following detailed description of one preferred embodiment thereof, disclosed by way of a non-limiting example, and by referring to the annexed sheets of drawings, in which:

Figure 1 shows in perspective view a molding press according to the invention, which is adapted for molding finished pieces from an extruded continuous strand of solid soap and like materials.

Figure 2 shows in a different scale a vertical section through the said molding press, taken transversely to the direction of the strand forward movement.

Figure 3 is another vertical section through the molding press, taken on line III-III of figure 2.

Figure 4 finally showsa constructional detail of the means for causing the strand to be advanced stepwise.

[0007] In figures 1 to 3, numeral 1 denotes as a whole the fixed supporting structure of an automatic molding press according to the invention, which is for molding finished pieces P directly from a strand B of soap and any similar products, continuously extruded from an extruder (not shown) of a known type.

[0008] At the side turned toward the extruder, the said structure 1 carries means for entraining the strand B, which preferably comprise a pair of horizontal parallel ribbons 2 facingly arranged at a short distance from each other, with the strand B being engaged therebetween.

[0009] Generally, in order to avoid any undesired slippage, each one of the said ribbons 2 consists of an inwardly toothed belt stretched between two guide sprockets 102, of which one is a motor-driven sprocket.

[0010] By the said ribbons the strand B is advanced step= wise, in such a manner that its end portion will be brought exactly in correspondence with molding means provided at the sides thereof, which are adapted for cutting and molding the pieces P.

[0011] Preferably, the said molding means comprise a mold 3 which is imparted a reciprocating motion, and cooperates with an oppositely arranged, box-shaped stationary matrix 4.

[0012] The mold 3 is carried by a slide 5 slidably mounted between rollers 6 and connected to a rockable driving arm 7, which by means of a connecting rod 8 is connected to a disk crank 9, which through reduction gearings 11, 12 is driven in rotation by the motor 10.

[0013] In order to enable the slide 5 to slide rectilinearly, the rockable arm 7 is fulcrumed at 107 about a compensating lever 13, which is in turn pivoted at 113 to the supporting structure of the molding press.

[0014] The box-shaped matrix 4, which is also called box, comprises an elastically movable molding bottom 104. More particularly, the bottom 104 is fitted to one end of a slidable stem 204 which is co-axially engaged by a cylindrical spiral thrust spring 304 that when in rest condition, positions the said bottom in correspondence of the opening of matrix 4. The said spring 304 bears against two spring-­supporting elements 404 and 504, of which the first is screwed to the free end of stem 204 and is designed for abutting, under the bias of spring 304, against a fixed abutment block 604, while the second is applied to the end of a bolt 704 screwed in a fixed support 804. Such an assembly of these components permits both to alter the position of the molding bottom 104 at the opening of matrix 4, and to adjust the thrust load of spring 304.

[0015] In the molding step, the mold 3 is moved forward against the opposite matrix 4, so that a portion of strand B located therebetween is inserted into the matrix, and a commensurate backward movement of the bottom 104 under the thrust of the piece molded, is caused to occur. Therefore, owing to the concurrent action of the matrix and the mold, every single piece is cut and is simultaneously molded by the mold, in cooperation with the opposed bottom 104.

[0016] Nextly, the mold 3 is drawn away from the matrix 4, and owing to the thrust of spring 304, the bottom 104 of the matrix can expel therefrom the finished piece P, which is taken up by an underlying horizontal ribbon 14 with its active upper stretch running either continuously or stepwise in the same direction as the strand B.

[0017] The separation from the matrix 4 of the already expelled piece P is assured by a pushing member 15 which in rest position is located just over the opening of matrix 4. The said pushing member 15 is carried by two lateral arms 115 which are pivotally connected at 215, and one of them is a square-shaped arm. At its opposite end, the square-shaped arm 115 comprises a washer element 315 which is engaged between two antagonistic means consisting of a cylindrical spiral compression spring 415 and a rod 16 fitted on pivot 17 so as to be rockable thereabout. The rocking movement of rod 16 is controlled by a cam 18 keyed onto the same shaft 19 for the rotation of the already mentioned disk crank 9, the cam 18 being into engagement with a roller 116 carried by the rod 16. It is obvious that the alternate prevalence of the spring 415 and of the rod 16 over their relative antagonistic means will respectively bring about the activation and the de-activation of the pushing member 15.

[0018] Of course, the operative sequence of the pushing member 15 and the molding means 3, 4, 104 results from the angular displacement between the cam 18 and the crank disk 9 on the common shaft 19 for their rotation.

[0019] As shown in figure 4, the sprockets 102 driving the facingly arranged ribbons 2 for moving forward the strand B carry on the shafts 202 for their rotation respective freewheel devices 302 which are engaged in counter-rotation by a chain length 20 which is alternately pulled in one direction by a driving lever 21 (see figure 2) and in the opposite direction by a return spring 22. The said driving lever 21 that causes the active travel of chain 20, i.e., the travel by which the freewheels 302 come to be coupled with the respective shafts 202 for the rotation of the driving rollers 102, is fulcrumed at 121 and is swung by a lever 23 connecting it to a second crank disk 24 which is also keyed onto the shaft 19. The said lever 23 is pivotally connected to a rod 25 which is fulcrumed at 125. The position of the fulcrum 125 of rod 25 is adjustable by means of the threaded stem 26, in order to render it possible to alter the arc over which the lever 21 swings, and thus the extent of the forward step of strand B.

[0020] Also in this case, the proper operative sequence of the means for moving forward the strand B and of the means for molding it, derives from the relative angular displacement of cranks 24 and 9.

[0021] In the molding press according to the invention some safety devices are provided.

[0022] One of these devices prevents the mold 3 and the movable bottom of matrix 4 from mutually coming into contact, thus damaging each other, in the instance in which, for any reason, the relative section of strand B is not present therebetween. The said device, which in itself is very simple, consists of a lever 27 which is fulcrumed at 17, and through a trace 28 is connected to a lever 7. Under normal operative conditions, the said lever 27 rocks idly, but when the said anomalous conditions occur, this lever pushes the spring-supporting element 404 so as to draw the bottom 104 away from the mold 3 in the course of being engaged with the matrix 4.

[0023] Another safety device provides for the possibility of an elastic sliding movement of the compensating lever 13, in the instance in which in correspondence of the molding means the thickness of the strand B comes to be increased owing to any accidental cause (such as, for example, owing to a finished piece sticking to one side of the strand end). In order to permit the said sliding movement, the lever 13 is movably engaged in a bushing 213 pivotally connected at 113, and cooperates with a return spring 313.

[0024] The adoption of molding means located at the sides of the strand being moved forward solves every problem of unloading the finished pieces P, which can be easily fed to underlying unloading means, such as the already mentioned ribbon 14. This ribbon is preferably driven at a higher speed than the strand, whereby a spacing between the finished pieces is obtained.

[0025] Of course, between the molding press and the strand-­extruding means adjusting means are provided, which conform the production rate of the molding press to the speed at which the extruded strand is advanced. The said adjustment means are described and shown in a former Patent Application of the same Patentee, relating to a similar molding press, and for this reason they are not discussed here in detail.

[0026] Moreover, in order to make the stepwise forward movement of strand B possible, it is provided for the same to take upstream of ribbons 2 a sinuous configuration, which is necessary for giving rise to an off-hand reserve.

[0027] From the foregoing, it is apparent that the molding press according to the invention affords very many technical and functional advantages, among which/
- an easy unloading of the finished pieces and of the waste material, if any,
- a simple construction and a high productivity,
- a reliable operation.

Claims

1. An automatic molding press which is adapted for molding finished pieces (P) from an extruded continuous strand (B) of a plastic material, such as a solid soap, a paraffin wax, and the like, characterized in that it comprises means (2) for conveying the extruded strand (B) along a horizontal path length, in correspondence of which molding means (3, 4) are arranged, which are adapted for acting in a horizontal direction upon the strand (B), transversely thereto, so as to make finished pieces (P) therefrom, to be taken up by underlying unloading means (14).

2. The molding press according to claim 1, wherein the means for conveying the extruded strand (B) comprise a pair of parallel horizontal ribbons (2) facingly arranged at a short distance from each other, with the strand (B) being engaged therebetween.

3. The molding press according to claim 2, wherein each ribbon (2) consists of an inwardly toothed belt stretched between two guide sprockets (102), one of which is a motor-driven sprocket.

4. The molding press according to claims 1 to 3, wherein the molding means comprise a mold (3) which is adapted for being cyclically engaged in an opposite box-­shaped stationary matrix (4) provided with a movable molding bottom (104).

5. The molding press according to claims 1 to 4, wherein the means (2) for conveying the extruded strand (B) are so operated as to cause the strand (B) to be advanced stepwise.

6. The molding press according to claims 4 and 5, wherein the mold (3) is imparted a reciprocating motion.

7. The molding press according to claims 4 to 6, wherein the mold (3) is carried by a slide (5) which is slidably mounted preferably between idle rollers (6), and is connected to a rockable driving arm (7) which by means of a connecting rod (8) is connected to a disk crank (9), which through reduction gearings (11, 12) is driven in rotation by a motor (10).

8. The molding press according to claim 7, in which the driving arm (7) is fulcrumed by its free end about a compensating lever (13), which in turn is pivoted to the supporting structure (1) of the molding press.

9. The molding press according to claim 4, wherein the bottom (104) of the box-shaped matrix (4) is slidable therewithin, and cooperates with adjustable elastic means (304).

10. The molding press according to the preceding claims, and provided with a pushing member (15) located over the matrix opening, which is adapted for assuring the separation of every single piece (P) formed by the matrix (4).

11. The molding press according to claim 10, wherein through an intermediate leverage (115, 16) the operation of the pushing member (15) is derived from a cam (18) that is keyed onto the same shaft (19) for the rotation of the crank disk (9) provided for operating the mold (3).

12. The molding press according to the preceding claims, wherein the sprockets (102) driving the ribbons (2) for moving forward the strand (B), carry on the shafts (202) for their rotation respective freewheel devices (302) which are engaged in counter-rotation by a chain (20) length alternately pulled in one direction by a driving lever (21) and in the opposite direction by a return spring (22).

13. The molding press according to claim 12, wherein the driving lever (21) is fulcrumed at an intermediate region (121), and through an adjustable intermediate leverage (23) it is swung by a second crank disk (24), that is keyed onto the same shaft (19) for the rotation of the said first crank disk (9).

14. The molding press according to the preceding claims, and provided with a lever device (27, 28) for preventing the mold (3) and the movable bottom (104) of the matrix (4) from fortuitously contacting each other.

15. The molding press according to the preceding claims, wherein the means for unloading the finished pieces (P) comprise a ribbon (14) which is driven either continuous= ly or stepwise, and is located under the molding means (3, 4).

16. The molding press according to claim 15, wherein the unloading ribbon (14) is driven at a higher speed than the means (2) for moving forward the strand (B).

17. The molding press according to the preceding claims, and comprising means which are adapted for forming, immediately upstream of the means (2) for moving forward the strand (B), a sinuous strand length that is necessary for giving rise to a certain off-hand reserve.

Drawing