Apparatus for charging a further processing system with objects which are in the form of bulk material

Objects, such as, for example, preforms for producing PET bottles, are feedable to silo as bulk material by a bulk material feeding device. A fill level sensor of the silo is connected to the control device. The control device actuates the feed drive in order to refill the silo with objects in dependence on the determined fill level of the silo. Connected downstream of the silo is an overhead conveyor and downstream of the overhead conveyor a separating-into-singles system. Both the overhead conveyor and the separating-into-singles system comprise sensors and drives, all the sensors being connected to the control device and the control device controlling all the drives.

The present invention relates to an apparatus for charging a further processing system with objects which are in the form of bulk material.

Apparatuses of this type are known in general and are used, in particular, for charging stretch blow machines with preforms for producing PET bottles or for charging inspection machines with objects which are to be inspected by said machines.

Document WO 2012/126129 A1 discloses a feeding device which is realized as a tipping device, has its own control device and feeds objects which are delivered as bulk material, such as preforms for hollow bodies, to a silo for refilling said silo. A control device is connected to a tipping drive, which forms a feed drive, and serves, in particular, for the purpose of ascertaining the fill level of the silo and, where necessary, refilling objects or rather preforms into the silo by means of the tipping device.

A conveyor device serves for the purpose of removing objects or rather preforms out of the silo and conveying them by means of a conveyor belt to a higher plane. In this case, this is an overhead conveyor which moves the objects or rather preforms to a transfer region. The objects or rather preforms are transferred from said transfer region to a separating-into-singles system which serves, in a known manner, for the purpose of positioning the objects or rather preforms correctly and arranging them in a row.

In the known devices for charging the further processing system with objects which are in the form of bulk material, further control devices are regularly present in addition to the control device of the feeding device, such as, for example, for the conveyor device and the separating-into-singles system.

Separating-into-singles systems are also known, for example document EP 2 441 708 A1 thus discloses a device and a method for aligning objects, in particular preforms for producing plastics material containers. The preforms are transferred to the input side of an alignment section by means of a conveyor device. In addition, the device is provided with an ejecting device which, by means of a return conveyor, returns non-aligned preforms, preferably directly to the input side of the alignment section.

Separating-into-singles systems with ejecting devices are also disclosed in documents WO 2010/006461 A1, WO 2010/006462 A1 and WO 2011/069268 A1.

The known apparatuses for charging a further processing system with objects which are in the form of bulk material require a great deal of space and are expensive and complex in regard to control measures.

It is consequently an object of the present invention to develop a generic apparatus further in such a manner that it can be realized compactly with simpler control means.

Said object is achieved with an apparatus for charging a further processing system with objects which are in the form of bulk material with the features of claim1.

The apparatus comprises a bulk material feeding device with a feed drive and a silo. Objects which are delivered as bulk material, such as preforms for the production of PET bottles, caps for the production of coffee capsules or other containers or hollow bodies, are feedable to said silo by means of the bulk material feeding device for intermediate storage. A control device actuates the feed drive in order to refill the silo with objects; this occurs at least in automatic mode.

A conveyor device, in particular an overhead conveyor, which comprises a conveyor drive, is connected downstream of the silo and a separating-into-singles system which comprises a separating-into-singles drive is connected downstream of said conveyor device.

The conveyor device is intended for the purpose of removing objects from the silo or rather of receiving objects fed to it from the silo and feeding them in a disordered manner to the separating-into-singles system. A disordered manner means that the objects comprise an arbitrary alignment and can be conveyed at a varying number per unit time.

The separating-into-singles system aligns the objects fed to it such that they can be conveyed further in a desired orientation and, in a preferred manner, in a row one behind another in the direction of the further processing system.

Both the conveyor device and the separating-into-singles system comprise sensors which are connected to the control device; the control device also controls the conveyor drive and the separating-into-singles drive in dependence on the signals from said sensors.

The apparatus according to the invention consequently comprises one single control device to which the sensors output their signals and which actuates the drives in dependence on signals from said sensors. Sensors can also be formed by switches which carry out the function of a sensor.

In a preferred manner, the control device comprises one single programmable control means which controls the entire apparatus.

The silo preferably has assigned thereto a fill level sensor which is connected to the control device. The control device actuates the feed drive in order to refill the silo with objects in dependence on the fill level of the silo which is determined by way of the fill level sensor—at least in automatic mode.

The silo can be realized as a so-called silo rucksack. It can, however, also be realized as a so-called silo belt, comprising a silo container and a silo conveyor belt. This latter is driven by means of a belt drive which is controlled by the control device. Objects are fed from the silo container to the silo conveyor belt or rather it removes them from the silo container and conveys them to the conveyor device.

The conveyor device is realized in a preferred manner as an overhead conveyor.

In its upstream starting region, the conveyor device preferably comprises a takeover funnel into which the objects delivered from the silo fall.

In a preferred manner, in the starting region, the conveyor device comprises an overfill sensor, which, where applicable, is assigned to the takeover funnel and is connected to the control device. If the overfill sensor detects an overfill with objects in the starting region, it outputs an overfill signal to the control device, which stops the belt drive or rather the feeding of objects out of the silo in order to prevent further feeding of objects until the overfill sensor detects that the overfill level has fallen below again as a result of the forwarding of objects by the conveyor device. A corresponding signal from the overfill sensor to the control device causes said control device to set the belt drive or rather the feeding of objects out of the silo in motion once again.

In a preferred manner, in its inlet region, the separating-into-singles system comprises a conveyor funnel into which the conveyor device delivers the objects.

In a preferred manner, in its inlet region, the separating-into-singles system comprises an overfilling sensor which, where applicable, is assigned to the conveyor funnel. If the overfilling sensor detects a predetermined overfill level has been reached, it outputs an overfilling signal to the control device which stops the conveyor drive. Where applicable, the belt drive of the silo conveyor belt is also stopped.

If the overfilling sensor detects the overfill level or a predetermined top-up level has fallen below, it outputs a corresponding signal to the control device such that said control device is able to restart the conveyor drive and, where applicable, the belt drive.

In a preferred manner, the bulk material feeding device is realized as a tipping device, as is disclosed in document WO 2012/126129 A1. The silo disclosed here for intermediate storage comprises a raisable cover which is raisable from the silo for refilling purposes by means of a mechanical connecting and power transmitting element of the tipping device.

A cover of this type can be present in conjunction with the present invention, but does not have to be present.

The tipping device comprises a tipper part, which is pivotably mounted on a frame and, controlled by the control device, is pivotable back and forth within an operating range between a lower loading position and an upper unloading position by means of a feed drive which is realized as a tipping drive.

The loading position and the unloading position each have assigned thereto a positional switch which is connected to the control device, forms a sensor and outputs a signal to the control device when the tipper part reaches the loading position or rather unloading position. The control device then stops the feed drive.

For safety reasons, in a preferred manner the loading position and the unloading position each have assigned thereto an emergency limit switch which also forms a sensor and is also connected to the control device. The control device triggers an emergency stop of the feed drive or rather of the tipping drive if the tipper part overshoots the operating range and, at the same time, actuates the relevant emergency limit switch.

In a preferred manner, the bulk material feeding device or rather the tipping device comprises a safety light grid which is connected to the control device. In a preferred manner, said safety light grid is arranged in the loading region of the tipping device. If the safety light grid detects an obstacle, it outputs a corresponding signal to the control device which stops the feed drive or rather the tipping drive in a reliable manner.

In a preferred manner, the tipping device is realized in such a manner that, with the tipper part situated in the loading position, a conveyor container with objects can be moved into the pivotable tipper part or an empty conveyor container can be removed from said pivotable tipper part. This is effected in the majority of cases using floor-level conveyors, e.g. using fork lift trucks.

To empty the conveyor container, the tipper part together with the conveyor container received by said tipper part is pivoted into the unloading position in which the parts are conveyed or rather poured out of the conveyor container into the silo.

The separating-into-singles system can be realized as is disclosed, for example, in documents EP 2 441 708 A1, WO 2010/006461 A1, WO 2010/006462 A1 and WO 2011/069268 A1.

The separating-into-singles system, which is realized in a preferred manner as a roller sorter, comprises in a preferred manner a maximum sensor which is connected to the control device and is arranged in a preferred manner in an upstream end region of the separating-into-singles system, where applicable at a spacing from the conveyor funnel. If the maximum sensor outputs a maximum signal to the control device, said control device stops the conveyor drive and, where applicable, the belt drive of the silo conveyor belt.

The maximum sensor ascertains whether a separating-into-singles system or rather an alignment section of the separating-into-singles system is filled with objects up to the limit of its detection range or not. If it is not filled, the conveyor device can continue to feed objects to the separating-into-singles system.

In addition, in a preferred manner, the separating-into-singles system comprises a minimum sensor which is also connected to the control device. Said minimum sensor is arranged in a preferred manner in a downstream end region of the separating-into-singles system or rather of the alignment section. If the minimum sensor outputs a minimum signal to the control device, said control device increases the speed of the separating-into-singles drive and, where applicable, of the conveyor drive and, if needs be, of the belt drive.

In a preferred manner, the separating-into-singles system, in a preferred manner approximately in the middle of the alignment section, and consequently, if present, between the maximum sensor and the minimum sensor, comprises a normal sensor which is also connected to the control device. Said control device controls the speed of the separating-into-singles drive in dependence on the normal signal output by the normal sensor.

The normal sensor ascertains for example, whether the separating-into-singles system or rather the alignment section is filled with objects from the downstream end up to said normal sensor. If this is the case and if the maximum sensor, which is present if needs be, ascertains that the separating-into-singles system or rather the alignment section is not filled with objects up to the limit of its detection range, the control device can allow the separating-into-singles drive to run at a constant speed.

If the normal sensor ascertains, for example, that the separating-into-singles system or rather the alignment section is not filled with objects up to the limit of said normal sensor, the control device actuates the separating-into-singles drive in such a manner that it operates at a faster speed.

In a preferred manner, the separating-into-singles system has connected downstream thereof a feed rail. A preferred embodiment of a feed rail is disclosed, for example, in document WO 2012/100357 A1. The feed rail takes over objects which have been aligned and arranged in a row one after another by the separating-into-singles system and guides them, usually sliding on sloping rails, to the further processing system which is connected downstream.

The feed rail, however, can also be realized as a horizontal rail; the aligned objects, which are arranged one behind another, are conveyed in a sliding manner along the rails thereof by means of an air or belt drive.

In a preferred manner, in an upstream end region which faces the separating-into-singles system, the feed rail comprises a rail maximum sensor which is connected to the control device. When the feed rail is being filled with aligned objects when the apparatus is started up, the maximum sensor outputs a rail maximum signal to the control device when the feed rail is filled with objects up to the limit of the maximum sensor.

The control device, as a result, outputs a ready signal to the further processing system. This ensures that the entire system can be started up in a reliable manner.

In many cases, further processing systems comprise an inlet unit to which the feed rail feeds the aligned objects. The inlet units in the majority of cases do not allow objects to be fed during system start-up until the further processing system has received a ready signal.

However, it is also possible for the feed rail to comprise, at a downstream end, a lock which prevents objects being delivered to the further processing system for filling the feed rail with aligned objects when the apparatus is started up. In said case, the control device opens the lock when it has received a rail maximum signal from the rail maximum sensor. This ensures that the entire system can be started up in a reliable manner.

In a preferred manner, in a downstream end region, where applicable upstream of the lock, the feed rail comprises a rail minimum sensor which is connected to the control device. Said rail minimum sensor outputs a rail minimum signal to the control device if it ascertains that no objects are present at said rail minimum sensor. In said case, the control device outputs a stop signal to the further processing system as objects can no longer be delivered in a reliable manner in the desired cycle for further processing.

In a preferred manner, the separating-into-singles system comprises a return belt which is driven by a return drive which is controlled by the control device. Said return belt is intended for the purpose of conveying incorrectly aligned objects which have been separated out by the separating-into-singles system either back into the silo or to the conveyor device or to the start of the separating-into-singles system.

In a preferred embodiment, the tipping device comprises a safety bolt by means of which the pivoted-up tipper part can be prevented mechanically from pivoting down. This is for safety reasons, for example when a person has to carry out work underneath the tipper part. A switch, which is connected to the control device, forms a sensor and, when the safety bolt is activated, outputs a corresponding signal to the control device which prevents the motors from starting-up, is present in a preferred manner with the safety bolt.

The apparatus shown inFIG. 1is intended for the purpose of aligning objects, in the present case preforms8, which are delivered in conveyor containers as bulk material, and feeding them arranged in a row one after another in the desired alignment to a further processing system10which is connected downstream of the apparatus. Said further processing system is shown symbolically as a circle; in the present case it is a generally known stretch blow machine for producing PET bottles from preforms8. Preforms are known in general, an example of a preform8is shown inFIG. 3.

The apparatus comprises a feeding device14which is realized as a tipping device12. A tipper part18is mounted so as to be pivotable about a horizontal pivot axis20on a frame-like frame16which is fastened to a floor or a base. A feed drive22in the form of an electric gear motor, the output shaft of which is connected to the tipper part18, is fastened to the frame16in order to pivot said tipper part from a lower loading position24, shown inFIG. 1, about the pivot axis20in the direction of the arrow S into an upper unloading position and back again.

The tipping device12is, for example, identically designed as is disclosed in document WO 2012/126129 A1. Reference is made explicitly to the disclosure in said document; the cover of the silo shown there not being necessary, but being able to be present.

The tipper part18is intended for the purpose of receiving, in the loading position24, a conveyor container25—for example a cardboard box or a metal box—which is loaded with preforms8as bulk material, it being possible for the conveyor container to be moved into the tipper part18, for example by means of a fork lift truck.

It is also possible to remove an emptied conveyor container25from the tipper part18in the loading position24.

To empty the conveyor container25, the tipper part18, driven by the feed drive22, is pivoted up out of the loading position in the pivoting direction S into the unloading position, whereupon the preforms8slide out of the conveying container, and consequently the tipper part18, as a result of their own weight into a silo26which is connected directly downstream of the tipping device12.

The silo26in the present case is a so-called silo belt, the silo26comprising a silo container28and a silo conveyor belt30.

In the present case, the floor of the silo container28is formed by four flat plates which—when viewed in cross section—are arranged in a W-shaped manner. Between the two lateral plates and the central plates there is in each case an outlet gap, through which preforms8are able to slide downward onto the silo conveyor belt30which is run beneath the silo container28.

A belt drive32(seeFIG. 2), which in the present case is also realized as an electric gear motor and which drives the silo conveyor belt30which is realized as a belt conveyor, is arranged on a silo frame which bears the silo container28and the silo conveyor belt30.

A conveyor device36, which is realized as an overhead conveyor34, is connected downstream of the silo26. Said conveyor device, as is disclosed, for example, in document WO 2012/126129 A1, comprises a conveyor belt with conveyor webs fastened thereon. In the bottom starting region of the conveyor device36, said conveyor device comprises a receiving funnel38, to which the silo conveyor belt30conveys the preforms8. In the receiving funnel38, the conveyor belt entrains preforms8by way of its webs and conveys them to the upper, downstream end of the overhead conveyor34. In the region of the overhead conveyor34, the preforms8comprise an arbitrary position and a varying number of preforms8can be entrained in each case by a web. The conveyor device36or rather the overhead conveyor34is driven by means of a conveyor drive40(seeFIG. 2) also in the form of an electric gear motor.

A separating-into-singles system42is connected directly downstream of the conveyor device36. On the input side, said separating-into-singles system comprises a conveyor funnel44, into which slide the preforms8which are conveyed upward by the overhead conveyor34. In the exemplary embodiment shown, this is a roller sorter, as is disclosed, for example, in documents EP 1 925 575 A1 and EP 2 441 708 A1.

Following the conveyor funnel44, when viewed in the conveying direction F, is an alignment section46of known design which is adapted to the objects to be sorted. Roller sorters include in a known manner two rollers or rather rows of rollers which are located opposite one another at an axial spacing. The preforms8to be aligned can only enter the gap between the rollers or rather rows of rollers in a certain alignment and in said gap they are secured against slipping, for example as a result of the collar that is usually present in the case of preforms8. The alignment section extends downward at an angle between its input side and its output side such that gravitational support for the aligning and the conveying of the preforms8is provided.

The separating-into-singles system42or rather, in the present case of a roller sorter, the two rollers or rather rows of rollers are driven by a separating-into-singles drive48which is also realized as an electric gear motor.

In the downstream end region, the separating-into-singles system comprises a known ejecting device, by means of which incorrectly aligned preforms8are ejected and fed in a known manner to a return belt50(seeFIG. 2). The return belt is driven by means of a return drive52which is also realized as an electric gear motor.

The return belt, in the exemplary embodiment shown, guides the ejected preforms8back to the receiving funnel38of the conveyor device36such that they are able to be fed anew to the separating-into-singles system42.

In the exemplary embodiment shown, following the separating-into-singles system42is a feed rail54which slopes in the conveying direction F as is disclosed, for example, in document WO 2012/100357 A1. The preforms8, aligned in their desired position and arranged one behind another, are transferred from the separating-into-singles system42to the feed rail54, along which they slide, aligned and following one after another in a row, to the further processing system10.

A control box58, in which a control device60with a programmable control means is situated, is additionally fastened on the machine frame56, on which both the conveyor device36and the separating-into-singles system42are arranged.

All the drives, that is to say the feed drive22, the belt drive32, the conveyor drive40, the separating-into-singles drive48and the return drive52, are actuated by the single control device60of the apparatus.

As can be explained in conjunction withFIG. 2, the apparatus also comprises, along with the mechanical components and the drives22,32,40,48and52, a number of sensors62which can also be present in the form of switches. In the embodiment shown, all the sensors62are connected to the control device60which actuates the named drives22,32,4048and52as a result of the relevant sensor signals.

In the exemplary embodiment shown, the tipping device12comprises a safety light grid64on the loading side. If an obstacle is present in the safety light grid64, the corresponding signal transmitted to the control device60results in said control device immediately stopping the movement of the feed drive22—in the present case the drive for tipping the tipper part18—or rather in preventing it from pivoting.

A first positional switch66, which is assigned to the loading position24of the tipper part18, and a second positional switch68, which is assigned to the unloading position, is fastened on the frame16of the tipping device12. The tipper part18actuates the first positional switch66in its loading position24and correspondingly the second positional switch68in the unloading position. The two positional switches66,68form sensors62and are also connected to the control device60.

If the tipper part18is loaded with a conveying container25with preforms8and if said preforms are to be fed to the silo26, the control device60controls the feed drive22in such a manner that it pivots the tipper part18from the loading position24about the operating range to the upper unloading position, where the tipper part18actuates the second positional switch68. As a result of the signal from said second positional switch68, the feed drive22is shut-off by the control device60. If the preforms8are discharged into the silo26, the control device60controls the feed drive22in the opposite direction in such a manner that the tipper part18, together with the empty container25, is pivoted downward out of the upper unloading position into the loading position24. Once said loading position24is reached again, the first positional switch66is actuated by the tipper part18, the signal thereof causing the control device60to switch off the feed drive22.

The emptied conveying container25can then be removed from the tipper part18, and said tipper part can be loaded with a new, further conveying container25which contains preforms8as bulk material.

One emergency limit switch70each is additionally fastened on the frame16adjacent to the first positional switch66and the second positional switch68, but outside the operating range. Should the tipper part18pivot outside the operating range due to a fault, the signal of the corresponding emergency limit switch70actuated by the tipper part18initiates the control device60to trigger an emergency of the tipping device12.

In addition, the pivoted-up tipper part18can be prevented mechanically from pivoting down by means of a safety bolt on the frame16. A switch which forms a sensor62ascertains whether the safety bolt is set or not. If it is, the signal it outputs to the control device60leads to the feed drive22not being actuated. If it is not, the feed drive22can be actuated to pivot the tipper part18.

Two fill level sensors72are assigned to the silo26. These monitor the fill level of the silo26with preforms8above the two silo valleys which are generated by the W-shaped realization of the floor of the silo26.

The fill level sensors72are also connected to the control device60. If a predetermined fill level is fallen below, the control device60actuates the tipping device12in such a manner that a conveyor container25filled with preforms8in the tipper part18is emptied into the silo26to fill up said silo. This is effected in such a manner when operated automatically or rather in automatic mode.

It is also possible, in manual mode, to control the tipping as a result of signals given manually.

The overhead conveyor34comprises in its starting region, that is to say in the area of the receiving funnel38, an overfill sensor74which is also connected to the control device60. If the overfill sensor74detects a predetermined maximum fill level of the receiving funnel38with preforms8, it outputs an overfill signal to the control device60. Said control device then stops the belt drive32such that the silo conveyor belt30does not feed any further preforms8to the conveyor device36, or rather to the overhead conveyor34. If the fill level in the receiving funnel38drops below a certain level again, the overfill sensor74outputs a corresponding signal to the control device60, which actuates the belt drive32again in order to feed preforms8once more to the overhead conveyor34.

In a corresponding manner, in its inlet region, in the conveyor funnel44in the exemplary embodiment shown, the separating-into-singles system42comprises an overfilling sensor76. If said overfilling sensor ascertains a predetermined level of preforms8present in the conveyor funnel44, it outputs an overfilling signal to the control device60. Said control device stops the conveyor drive40such that the overhead conveyor34temporarily does not feed any further preforms8to the separating-into-singles system42. If the level of preforms8in the conveyor funnel44drops below a certain level again, the corresponding signal of the overfilling sensor76in the control device60results in said control device setting the conveyor drive40in motion again in order to feed preforms8once again to the separating-into-singles system42.

The control device also controls the belt drive32in a manner corresponding to the conveyor drive40as a result of the signals from the overfilling sensor76.

The separating-into-singles system42comprises a maximum sensor78downstream of the conveyor funnel44, but in the vicinity thereof. Said maximum sensor is arranged in the upward end region of the alignment section46and outputs a maximum signal to the control device60if the alignment section46is filled with preforms8from the downstream end up to the maximum sensor78. If a maximum signal occurs in the control device60, said control device stops the conveyor drive40and the belt drive32such that temporarily no further preforms8are fed to the separating-into-singles system42.

In addition, the separating-into-singles system42comprises a minimum sensor80in a downstream end region, at a spacing from the end of the alignment section. If said minimum sensor ascertains that there are no more aligned preforms8present within its sensor range, it outputs a minimum signal to the control device, as a result of which the control device60increases the speed of the separating-into-singles drive48such that the separating-into-singles system42, or rather the alignment section46thereof, is once again filled with aligned preforms8.

In addition, the separating-into-singles system42comprises a normal sensor82in its center region, that is to say between the maximum sensor78and the minimum sensor80. Said normal sensor detects whether aligned preforms8are present in the alignment section46up to its sensor range. Said control device controls the speed of the separating-into-singles drive48in dependence on the normal signal output to the control device60by the normal sensor82.

In its upstream end region of the feed rail54, said feed rail has assigned thereto a rail maximum sensor84which is connected to the control device60. If the feed rail54—when the apparatus is started up—is filled up to the rail maximum sensor84with aligned, consecutive preforms8, the rail maximum sensor84outputs a rail maximum signal to the control device60, which outputs a ready signal to the further processing system. The further processing system can be started up as a result.

As an alternative to this, the guide rail54can comprise a lock at its downstream end. Said lock is intended, when the apparatus is started up and the feed rail54is consequently to be filled with aligned preforms8, for the purpose of preventing the output of preforms8to the further processing system10until the feed rail54is filled up to the rail maximum sensor84with aligned, consecutive preforms8. If this is the case, the rail maximum sensor84outputs a rail maximum signal to the control device60which opens the lock86such that preforms8are then able to be fed to the further processing system10.

In addition, in a downstream end region, where applicable upstream of the lock86, the feed rail54has assigned thereto a rail minimum sensor88which outputs a rail minimum signal to the control device60if no preforms8are present within its sensor range. In this case, the control device60outputs a stop signal to the further processing system10such that said further processing system can be shut down until preforms8are once again ready to be output to the further processing system10.

It must be mentioned for the sake of completeness that the bulk material feeding device14can comprise a different apparatus for feeding bulk material into the silo26in place of a tipping device12. The silo26can also be realized as a “silo rucksack” in place of a so-called silo belt. The conveyor device36does not necessarily have to be realized as an overhead conveyor34nor the separating-into-singles system42as a roller sorter. Correspondingly different forms of realization which fulfill the same task are generally known.

It must also be mentioned that hydraulic drives can also be used in place of gear motors for the drives.