The invention relates to a compactor for compacting e.g. plastic bottles and/or cans of metal, said compactor being constructed in a chassis which contains two rotating bodies with conical surfaces having a compaction area, said conical surfaces being disposed close to each other, as well as a receiving area and an ejection area, in which the plastics bottles and the cans of metal are respectively fed to and ejected from the compactor, said conical surfaces being formed with an embossment thereon.

A compactor for compacting metal cans is known e.g. from US Patent No. 4 432 278. In this known compactor, the metal cans are moved inwards be¬ tween two conical plates which are driven by the same motor. The two conical plates may have a rough surface which contributes to retaining the metal cans between the plates in the area just before the actual compaction of these takes place.

A similar compactor is known from the published CA Patent Application No. 2095402. In this compactor, the conical surfaces are formed with radially extending ribs which contribute to ensuring that the metal cans get into the compaction area.

It has been found, however, that feeding of particularly plastics bottles into the compaction area may be problematic, since they will tend to jump back as soon as they get close to the compaction area.

Accordingly, an object of the invention is to provide a compactor of the type defined in the opening paragraph, which is capable of rapidly and effec¬ tively feeding plastics bottles and metal cans into the compaction area in a compactor. The object of the invention is achieved by a compactor of the type defined in the introductory portion of claim 1, which is characterized in that discrete, resilient retention elements are formed in the one conical surface, or that a plurality of pressure rollers is arranged on the outer side of the two rotating bodies, preferably two on the outer side of each rotating body.

Hereby, the metal can or the plastics bottle is retained in such a manner that the retention takes place somewhat before the actual compaction area, and such that the retention increases in step with the approaching of the plastics bottle or the metal can to the compaction area.

When, as stated in claim 2, the resilient retention elements are constructed as pistons which are mounted in bushings, said pistons and said bushings having a spring disposed between them, the retention elements may be provided with a relatively great height, causing metal cans and plastics bottles to be retained with a not too strong initial pressure just after they have been received in the receiving area of the compactor.

Expediently, as stated in claim 3, the pressure rollers are biased by springs, such as disc springs, as this provides an even pressure between the rotat¬ ing bodies, which is advantageous in particular in connection with the com¬ paction of packages of an uneven wall thickness.

As will be known, a deposit-refund system has been established for metal cans and plastics bottles. To ensure that a deposit is not refunded several times for the same metal can or plastics bottle, it is expedient, as stated in claim 4, that circular grooves are additionally provided in the surface of the one rotating body, said grooves being adapted to receive elevations which are provided on the surface of the other rotating body.

This is important in particular if the compactor is set up at a self-service lo- cation where customers return used metal cans and plastics bottles.

To ensure that the compactor is not unduly overloaded during the compac¬ tion of plastics bottles and metal cans, it is an advantage if, as stated in claim 5, the rotating bodies are driven by their respective motors, and that they are resiliently connected with the motors by means of a spherical bearing.

This provides for some resilience in the compactor, thereby preventing the application of great, undesired forces between the conical plates.

When, as stated in claim 6, a wall section is arranged along the circumfer¬ ence of the rotating bodies at their opening, and, as stated in claim 7, that the wall section is formed by two movable guide bands, where the one movable band extends from the start of the narrow part of the open area toward the broader part of the open area, and where the band extends a small length which merges into a greater length perpendicularly to the small length, and that the other band extends longitudinally of the open area, said plastics bottles and/or said cans of metal being fed from the broad part of the open area toward the narrow part of the open area in the compaction area, it is ensured even more that the plastics bottles and/or the cans of metal do not "jump" out of the compactor during their transport toward the compaction area. The band ensures an even feeding toward the compac¬ tion area of the plastics bottles and/or the cans of metal.

To completely avoid the situation that the plastics bottles and/or the metal cans jump out of the compactor, it is advantageous if, as stated in claim 8, a plate part is mounted along and above the other band.

To avoid unnecessary noise nuisances, which may arise if plastics bottles with plugs or cans or bottles which are perhaps full, are fed toward the compaction area, it is an advantage if, as stated in claim 9, a perforator is arranged along the circumference of the lower rotating body, and, as stated in claim 10, that the perforator is arranged after the other band before the compaction area.

This perforator may expediently be constructed as stated in claim 11 , said perforator being formed by a toothed wheel which is mounted rotatably on a spring-biased rod.

To ensure that all compacted plastics bottles and metal cans are ejected from the compactor after compaction, it is an advantage if, as stated in claim 12, an ejector in the form of two plates is arranged in the gap be¬ tween the conical surfaces after the area where the conical surfaces touch each other, one rim of each plate adjoining a conical surface of its own, said plates being connected with each other by means of a resilient ar¬ rangement.

Hereby, the ejector will never allow creation of a lowermost slot through which a flattened plastics bottle or metal can may pass.

Since, as mentioned, the compactor is adapted for compacting both metal cans and plastics bottles, and since it is desirable that these are sorted separately, it is an advantage if, as stated in claim 13, a chute is arranged in the area between the compaction area and the ejector, said chute being capable of assuming an inclined or an almost vertical position, said chute being controlled by an identification unit which signals the chute whether a plastics bottle or a can of metal is compacted, said chute sorting the com¬ pacted packages such that all compacted plastics bottles are fed down into a first section in a two-part container, while the compacted metal cans are fed down into a second section of the two-part container. As stated in claim 14, the movement of this chute may expediently be pro¬ vided in that the chute is connected with one end of the connecting rod, while the other end of the connecting rod is connected with a crank which is driven by a motor.

The invention will now be explained more fully with reference to the draw¬ ing, in which

fig. 1 shows the compactor according to the invention, seen in perspective,

fig. 2 shows the compactor of fig. 1 , seen from another angle,

fig. 3 shows a detailed cross-section of the rotating bodies,

fig. 4 shows in detail the structure of a retention body which forms part of the compactor according to the invention,

fig. 5 shows the structure of an ejector whch forms part of the compactor according to the invention,

fig. 6 shows the compactor of fig. 1 , said compactor being equipped with a guide band,

fig. 7 shows the structure of the guide band,

fig. 8 shows the compactor of fig. 1 and fig. 6 equipped with a perfora¬ tor,

fig. 9 shows the structure of the perforator, fig. 10 shows the two rotating bodies with pressure rollers on their outer sides, seen from the side, while

fig. 11 shows how the pressure rollers are disposed on the outer side of the uppermost rotating body.

In figs. 1 and 2, the numeral 1 generally designates a compactor according to the invention which is incorporated in a chassis.

As will be seen, it has two rotating bodies 2 and 3, respectively, with conical surfaces having axes of rotation which form an angle with each other, thereby providing a varying opening between the bodies which extends such that the place where the opening is greatest is offset by 180° from the place where there is no or just a very limited opening, cf. also the following.

The rotating bodies are driven by their respective motors 15, 16 via shafts 24, 25.

An ejector 4, whose structure and function will be explained more fully in connection with fig. 5, is arranged between the rotating bodies.

As will additionally be seen, a chute 5 is disposed near the ejector 4 just outside the rotating bodies, said chute being connected by means of a con¬ necting rod 7 and a crank 6 with a motor 8, which may cause the chute 5 to assume two positions, as will be explained later.

A container is placed below the chute 5 inside the chassis, having two sec¬ tions 10 and 11 which are intended to receive compacted plastics bottles 9, 12 in the section 11 , while the section 10 is intended to receive compacted metal cans 13. As will be explained more fully later, it is the setting of the chute 5 which determines that compacted plastics bottles are to be fed down into the container section 11 , while compacted metal cans are to be fed down into the container section 10.

As will be seen best from fig. 2, a plurality of resilient retention elements 17, 18, whose structure will be explained in connection with fig. 3, are secured on the upper conical body 2, on its surface. In the figure, the resilient reten¬ tion elements are shown with positions which may be close to the centre of the conical body or close to the periphery of the conical body.

Further, the uppermost conical body is formed with some circular depres¬ sions which, in the area where the rotating bodies adjoin each other, may engage grooves 20, cf. fig. 1 and fig. 3, which are provided in the lowermost conical body 3.

With reference now to fig. 3 and fig. 4, the structure of the rotating bodies and their function will be explained more fully.

Fig. 3 also shows the retention elements 17, 18, which are shown in fig. 4 on an enlarged scale and in section. The retention elements are formed by a piston 17 which is mounted by means of a spring 21 in a cavity of a bushing 18 in which it may be moved. As will additionally be seen, the bushing is secured to the upper side of the upper, conical body 2 by means of screws (not shown) which may be inserted into screw holes 22.

Fig. 3 shows a plastics bottle 14 which is about to be compacted, it being fed in a clockwise direction during the rotation of the lower conical body. The upper conical body also rotates in a clockwise direction.

During the rotation of the rotating bodies the plastics bottle will slide in- wards toward the narrower part of the opening between the rotating bodies, which causes a piston of a retention element to grip the plastics bottle and retain it with an increased force, since the spring 21 of the piston will affect the plastics bottle with an ever increasing force until the piston 17 is seated entirely in the bushing, and such that the surface of the piston is flush with the surface of the upper conical body.

The plastics bottle is compacted during the continued rotation, and when it reaches the area where the rotating conical bodies touch each other, the grooves 20 and the elevations 19 will provide an embossment in the com¬ pacted plastics bottle.

To prevent the creation of a force between the rotating bodies which is so great as to involve the risk that the compactor fails, which may be the case if an attempt is made at compacting a solid body by mistake, the axes of the two conical bodies are suspended resiliently by means of spherical bearings, which are designated 22 and 23.

These spherical bearings will allow the rotating bodies to tilt slightly, such that the smallest distance between the rotating bodies may be varied. For instance, the upper rotating body in fig. 3 will be able to tilt slightly to the left, while the lower rotating body 3 will be able to tilt slightly to the right.

In addition, a switch may be provided, which activates an interruption of the compaction if e.g. it is attempted to compact a very rigid and thick object.

This interruption may be provided in many different ways, e.g. as weighing cells registering at desired places whether the forces between the rotating bodies exceed a maximally permissible value during a compaction process.

After the compaction and the embossment of the plastics bottle, it is con- veyed toward the ejector 4, where it is pushed away from the rotating bodies down into the two-part container. Since the rotating bodies are allowed to perform a certain mutual tilting relative to their axes, it is necessary that the ejector is constructed with this in consideration. However, it is necessary that the distance between the lowermost edge of the ejector and the lowermost rotating body is constantly kept as small as possible, since, otherwise, compacted plastics bottles or compacted cans of metal will slide below the ejector and move once more round between the two rotating bodies, which, of course, is not desirable since it may cause unintentional operational stoppages if a plastics bottle already compacted continues round between the rotating bodies of the compactor together with a newly arrived plastics bottle, which is to be com¬ pacted.

Therefore, cf. fig. 5, the ejector 4 is constructed as two triangular plates 26, 27 with edges 32, 33 forming an abutment with the uppermost 2 and the lowermost 3 rotating body. The two plates are connected with each other by means of springs 28 which try to urge the plates 26, 27 apart with a certain force, and such that the edges 32, 33 are constantly in contact with the ro¬ tating bodies 2, 3, which means that the plates may follow the tilting move¬ ment of the rotating bodies so that openings will not be created between the surfaces of the rotating bodies and the edges 32, 33 of the plates.

The two plates of the ejector moreover have elongated holes 30 through which pins from a mounting plate (not shown) are passed, such that the plates may be secured by the pins and are allowed to perform a sliding movement whose extent is defined by the length of the holes.

Finally, the edge 32 of the uppermost plate 26 is formed with recesses 31 which allow the pistons 17 of the retention elements to pass during the ro¬ tation of the rotating bodies.

As mentioned, the compacted plastics bottles and cans of metal are pushed away from the rotating bodies after completed compaction.

Since it is desirable to sort the compacted plastics bottles from the com¬ pacted cans of metal, a two-part wheeled container is inserted at the bot- torn in the chassis, said container having two container sections 10, 11 , where the one container section 10 is intended to receive compacted cans of metal, while the other container section 11 is intended to receive com¬ pacted plastics bottles 12.

The sorting takes place by means of a chute 5 which is arranged above the two-part container, and which is movable between two positions controlled by a motor 8, which is connected with the chute 5 via a crank 6 and a con¬ necting rod 7.

The movement of the motor is controlled by a signal which is provided by an identification unit known per se, which identifies which types of pack¬ ages are fed into the compactor.

The sorting takes place as follows:

If the identification unit has identified a compacted can of metal, the motor 8 is signalled to place the chute vertically or almost vertically, and then the compacted can of metal, when reaching the ejector 4, will drop down into the container section 10. If the situation is such that it is a compacted plas- tics bottle, which is shown at 9 in fig. 1 , then the chute will assume the in¬ clined position shown in fig. 1 via the activation of the motor, which causes the plastics bottle 9 to slide down the chute 5 into the second container section 11.

Fig. 6 also shows the compactor of fig. 1, but now, cf. also fig. 8, equipped with a wall section 34 which is formed by two guide bands 35, 36 and 37, where the first guide band 35 extends longitudinally a small length from a narrow part of the open area between the rotating bodies toward a broader part of the open area between the rotating bodies. The first guide band is extended by a greater length 36 which is perpendicular to the small length.

The second guide band 37 extends longitudinally of the broad part of the open area toward the narrower part of the open area toward the compac¬ tion area. The first band is driven by a motor (not shown) and is mounted on three rollers 40, 41 , 42 as well as a pressure roller 39, while the second band, which is also driven by a motor (not shown), which may be common to both bands, extends around two rollers 43, 44. A plate part 38 is mounted on top of the second band 37.

Fig. 8 also shows the compactor of fig. 6, but now equipped with a perfora- tor 45, cf. also fig. 9.

The perforator 45 is arranged just before the compaction area longitudinally of the circumference of the lower rotating body in extension of the second wall section 37.

As will be seen best in fig. 9, the perforator is formed by a toothed wheel 46 mounted on a rod 47 which is biased by a spring 48 such that the rod is fixed between a curved plate part 49 and a holding bushing 50 mounted on a mounting plate 52. The rod is secured to the mounting plate 52 via a shaft which has a pivot 51 so that the rod may be pivoted away from the curved plate part 49 against the force of the spring 48, which may also have a certain spring effect. The toothings may be configured as awls or knives and serve to perforate bottles and/or cans of metal just before they are compacted, such that loud crashes during the compaction are eliminated.

With reference now to fig. 9 and fig. 10, it will be explained how the two ro- tating bodies 2, 3 may be pressed against each other in an alternative em¬ bodiment with respect to the retention elements 17, 18, which were ex¬ plained in connection with fig. 3 and which are disposed on the inner side of the one rotating body.

According to figs. 9 and 10, pressure rollers 51 are used, which press against the outer side of the two rotating bodies 2, 3 by means of springs 52 expediently formed by disc springs, which may be placed in a holder (not shown) secured to an attachment point at a suitable place on the chas- sis of the compactor.

The pressure rollers are fixed such that the direction of movement of the rollers is tangent to the rotating bodies.

A total of two pressure rollers is arranged on each of the rotating bodies, two of which are seen from above in fig. 11. The one is designated 51 , while the other is designated 55. All four pressure rollers press independ¬ ently of each other so that optimum compaction may be achieved, also in connection with packages whose thickness may vary from top to bottom.