« PreviousContinue »
VERTICAL PARALLEL TRANSPORTATION
CROSS-REFERENCE TO RELATED
This application claims benefit under 35 U.S.C. § 120 and is a divisional of U.S. application Ser. No. 10/829,387, filed Apr. 22, 2004 now U.S. Pat. No. 7,331,443.
FIELD OF THE INVENTION
The invention is concerned with a process for the conveying of closures made from metal sheet (metallic sheet).
BACKGROUND OF THE INVENTION
Conveyer devices for preferably vertical conveying of closure lids made from magnetically attractable (ferromagnetic) metal sheet are in essence a way of separating a quantity of 20 individual closures collectively conveyed or taken from a container, and which are guided together to form a line of closures, which line is conveyed upwards by a conveyer belt in longitudinal direction. In the course of longitudinal conveying, a blow-off device, which is coupled functionally to a 25 sensor device which detects whether the closure, which in each case has just arrived below the sensor device, is placed in the row in the correct position or in the wrong position, is arranged laterally at one point of the conveyer belt. This identification can be achieved easily due to the cap structure 30 of the closure lid, because the covering wall (surface or "panel") of the closure lid of U-shaped section produces a different sensor signal than the measurement in the hollow interior of the cap. Therefore the closure lids, which lie in the row with their edge bars or edges on the conveyer belt and 35 with their flat upper sides (covering walls) pointing towards the sensor, may be easily identified. These caps are blown off laterally by a pulse of compressed air so that fewer closures remain, which are conveyed in longitudinal direction, after the sensor and discharge device. Hence the closures are 40 cleared-up with regard to their position. Hence, only correctposition closures are found in the row which is now provided with gaps, so that the conveying capacity is reduced (internal use, no publicly accessible reference known).
In order to compensate the reduction in conveying capac- 45 ity, attempts have been made for a long time and also developments successfully concluded, in which the cap-like closures—instead of being blown off—are rotated using a turning device and again placed in the row, see for example WO-A 01/55014 (CCS&CMB), page 8 there, lines 16 to 22 50 and claim 13 there, feature (ii). A reduction in the performance, measured in (correctly lying) closure lids ("closure") per minute (or lids or caps per minute) may thus be avoided, in each case compared at the same speed of the conveyer belt.
BRIEF SUMMARY OF THE INVENTION
The invention takes a different path. As a technical way of looking at a problem, it may not only retain the conveying capacity (performance), but optionally also increase it with- 60 out using an expensive device for turning the lids or having to accelerate the belt. Rej ecting the aim of the state of the art, the performance should thus be able to be increased even if the speed of the belt is reduced. Performance is understood to mean below the number of conveyed lids/minutes, which 65 currently reaches an order of magnitude of about 800 lids/ minute.
According to the invention as claimed, considerably more or a large number of lids are supplied in parallel to a sensor and discharge device on the conveyer belt, so that the loss due to discharge of lids not placed in correct position is not crucial or hardly crucial.
According to the invention, the performance may be almost doubled, easily dependent on how many closures are situated in the wrong position in the several rows (preferably two rows) of supplied lids.
For two tracks or lines of parallel conveyed lid rows which are supplied adjacently on the conveyer belt, separated by a bar which divides the conveyer belt preferably essentially centrally into two longitudinally directed elongated conveying sections, the conveying capacity is virtually doubled. The two rows supplied to the sensor and discharge point are guided together again after the end of the bar physically separating them, following the sensor and discharge device, in order to form a row of closures following one another closely or a virtually gap-less chain of closures. This row may also be called a "closure string" or a virtually gap-less chain of lined-up closures, whicharereleasedforfurtherprocessing or processing at the outlet of the conveyer device.
The supply of such closure lids may take place from a container, in which they are stored in bulk. Suitable metallic (ferromagnetic) closures are those which are used in packaging technology, for example sheet metal lid closures with covering wall and peripheral wall and thereon radially inwardly pointing cams for forming "cam rotary closures". They may be conveyed by the device, wherein the released closure string of lids is either further processed or is further conveyed to the closing machine.
Under the assumption of doubling the supplied quantity indicated above at the same speed of the conveyer belt, it depends on the number of lids not lying in the correct position as regards the actual capacity increase achieved. Assuming hypothetically that no such lids are in both conveying strings, the capacity may be doubled. However, usually this cannot be assumed so that a certain number of supplied lids do not lie in the correct position, statistically seen in each row half, so that the performance is at least equal even without a lid turning device with respect to single-track conveying supplied only in correct position. In a comparison with single-track conveying—with lids statistically distributed half in correct position and half in wrong position—the invention achieves essentially virtually double the performance.
Those lids which lie in the wrong position are rejected at the sensor and discharge station only from the direction of running of the belt, in most cases laterally ejected, and fall back into the container described, from where they are taken up again and supplied.
Ej ection of the lids may take place on two sides, depending on the separating device as, for example the bar, which both lid rows pass guided in parallel. Starting from that, ejection may take place to the one or to the other side, that is on both sides. A blow-off pulse of compressed air thus comes from the centre of the belt and is triggered by nozzles which are directed in opposite manner. They are arranged firmly on the bar and do not change their height relative to the surface of the belt for a size/height of closure lids. If the type of conveyed closure lids is changed, that is either in their diameter or in their height, adjustment may take place at the sensor and discharge device. At least the sensors of the sensor and discharge device may thus be adjusted at a height relative to the surface of the belt. The sensitivity of the sensors may also be adjusted by the height adjustment.
Tests have shown that increases in capacity up to 1,500 lids/minute may be achieved using the conveyer method as claimed for essentially the same belt speed of a comparable plant.
Discharge is favoured if the sensor device and the dis- 5 charge device are spaced slightly in longitudinal direction in each case on one of the two adjacent conveying sections. Hence, time delays may be compensated by the sensor when detecting a wrong-position closure, whereas the conveyer belt continues to move the closure lid just measured and detected by the sensor.
Laterally projecting guide strips may conduct the rejection of the lid and ensure that the lateral ejection movement is always converted into a downward movement, supplemented 15 by the force of gravity, so that the lids lying in the wrong position are returned to the collecting container.
If the sensors can be adjusted in their height position relative to the belt surface, the conveyer device may be adapted in height to different lids. Different lid diameters between, for example about 27 mm up to for example about 53 mm may also be conveyed by the same arrangement which is only limited in the conveyable maximum diameter in that the remaining belt sections on both sides of the bar should still be 25 so wide to be able to accommodate the flat sides (the ferromagnetic covering walls) of the lids and to convey them by frictional force, whereas magnets are provided which press the lids onto the surface of the conveyer belt with their magnetic force. Adjustment of the distance of the elongated mag- 30 net may influence this force, which acts on the ferromagnetic lids.
In the guiding-together region, an elongated magnet, which is at an angle with respect to the longitudinal axis of the belt and which favours guiding together is provided. It starts from the end of the first elongated magnet which essentially terminates where the sensor and discharge device is arranged, and extends at an angle upwards in the direction towards one edge of the belt in the case of a vertically standing device. 4Q Both rows of closures cleared of wrongly lying closures are guided together by this magnet guide lying at an angle and reach the discharge end. Guiding together takes place on the same conveyer belt, on which supply to the sensor and discharge device also took place, only after the latter. Without 45 interposing further conveyer belts or diverting points for the conveyed closure lids, supplying of the non-uniform lid rows and guiding together of only correct-position lid rows is achieved in a small space or a short length.
A further guide member may achieve support here and 50 improve the formation of the row of closures following one another closely. It is arranged upstream of the discharge and at a distance from the sensor and discharge device. It has a guide surface or guide edge at an angle to the longitudinal axis of the belt or central plane and can be pivoted in a small 55 pivoting angle about a pivotable bearing, depending on a pressure which is exerted on the guide member by the several closure lids supplied—in the guiding-together region.
The guide member at the discharge end is biased by a spring force (resiliently flexible), so that deflection effects an 60 increase in spring force, in order to optionally release wedged lids at their pointed end (nose end) and to make them either into such lids which run into a feed hopper to form the lid row following one another closely or to make them into such lids which slide along a deflecting edge of this guide member and 65 are deflected laterally from the conveyer belt in order to also fall back into the collecting container.
The guide member after the sensor and discharge device guides together the several separate rows in a guiding-together section into the row of closures following one another closely.
The elongated magnetic device in the guiding-together region and/or the elongated magnetic device in the upstream region, which upstream magnetic device extends into the sensor and discharge region, may be composed of individual piece magnets, which are inserted in an elongated, flat support arrangement. An elongated magnetic device, which fixes the single individual magnets against one another, is thus produced. Due to the position of the accommodation points in the support arrangement, track sections (guide lines) are defined which consist in each case of individual magnets. At least one of these track sections is inclined with respect to a central plane of the conveyer belt in order to form the inclined elongated magnetic device. This inclination relates to the guidingtogether region, where a row is formed from several rows of closure lids, which takes place like points by presetting the individual magnets along guide lines at different angles—to a vertical (for example the central plane).
Also upstream of the guiding-together region, the elongated magnetic device may consist of two spaced rows of individual magnets, which are arranged so that in each case one row lies on this side and that side of the bar and is arranged below the conveyer belt.
BRIEF DESCRIPTION OF FIGURES
The invention is illustrated and supplemented using exemplary embodiments.
FIG. 1 is a schematic view of a first section 2, 3 of the conveyer device.
FIG. 2 is a schematic view of a second section 4, 5 of the conveyer belt, above FIG. 1.
FIG. 3 is a complete view of the vertically erected conveyer device with sections 1 to 6.
FIG. 4 illustrates schematically elongated magnetic devices 50, 51 which are arranged in the upper part section 3 of the first section 2, 3 and in the lower part section 4 of the second section 4, 5 below the conveyer belt. The magnet pieces, which are circular here, are not closure lids as have been illustrated in FIGS. 1 to 3.
FIG. 5 is a section in the direction of the central plane corresponding to the track path 56, wherein at the top the conveyer belt 10 and at the bottom an elongated support device 53 with the magnet pieces, which can be seen in FIG. 4, are shown in detail.
FIG. 6 is a schematic view of the distance relationships of the magnet pieces based on a closure lid D to be conveyed.
DETAILED DESCRIPTION OF PREFERRED
The device for conveying the metallic closure lids operates vertically, as may be seen using an example from FIG. 3. Starting from a container—not shown in more detail—lying at the bottom in section 1 of the conveyer device, into which a continuous conveyer belt 10 engages, closure lids D are moved upwards along two tracks on the continuous conveyer belt 10. A combined section of sensors 17, 19 and discharge devices 16, 18, which may be formed as metal sensors or blowing nozzles for compressed air ejection, is situated in section 3 approximately at the central height. A bar 15 extends into the collecting container and lies above the upper side of the upper conveyer strand of the conveyer belt 10. The bar extends into the section 3, where the sensor and discharge