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ALIGNMENT AND ORIENTATION FEEDER Technical Field
The present invention applies to devices used for aligning and orienting randomly oriented parts in order to feed them in a desired orientation to a subsequent production process.
The particular applicability envisaged for this invention, by way of example, is in the feeding of short, double open ended flexible plastic or metal/plastic laminated tubular articles, being the bodies of toothpaste or similar tubes, known as and referred to hereinafter as "squeeze" tubes, which have been printed externally and subsequently stored prior to being fitted with the tube heads. The "head" of the tube, in this context, is the generally conical transition region which adapts the cylindrical body portion of the tube, typically 20 to 50 mm diameter, to a threaded neck able to accept a screw-on cap, the neck opening typically being of 5 to 8 mm diameter.
As well as for the purpose of supplying squeeze tube bodies to a heading operation, a further example of the applicability of the invention is in the taking of a randomly oriented supply of headed squeeze tubes in order to present them in a desired orientation for filling with a particular product.
Squeeze tubes are typically manufactured in a limited number of diameters, perhaps in the order of ten, but are finished in a considerable number of lengths and a very great number of differently decorated designs. The decoration consists of usually multiple colour printed matter on the tube body and the term
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"decoration" includes such matter as trade description and mark(s), mass or volume of contents and user instruction.
It is only rarely economical for a manufacturer or filler of squeeze tubes to devote a single purpose production line to a single tube size and filled product type, because of the high investment cost in a tube production line and the diversity of sizes of tube and diversity of filled product types involved. The various machines used in the entire process are multi-purpose having a complexity which results in considerable time expenditure by skilled technicians each time resetting and adjusting each machine variable is required. For maximum economy of production it is therefore preferred to minimise the number of line changes and so, as a regular practice, to store printed tube bodies waiting heading. Subsequently it is also preferred to store printed and headed tubes completed up to the point where they will most probably have been delivered to the premises of a filler of such tubes and are ready to be fed to a filling machine. In both these instances it is most convenient to store the articles randomly aligned in large bulk containers such as plastic bags. Although a method involving the storing of the aligned and oriented tubes in magazine type containers is known, this option is not very frequently adopted because of the high cost of magazines together with their limited capacity. Hence there is a need for a device capable of accepting an unsorted and unoriented bulk supply of tubes and feeding them in a desired alignment to subsequent processes, the device requiring minimal human attendance once set up and started.
The preferred order of manufacturing steps in the production of all-plastic tube bodies is as
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1. Manufacture tube body material by extruding tube of the desired diameter;
2. Cut to length as soon as cooled following extrusion;
3. Store the tube bodies randomly bagged in bulk; 4. Print the decoration and the like on tube bodies;
5. Store the tube bodies randomly bagged in bulk;
6. Mould the heads onto the printed bodies; 7. Apply caps such as screw caps to the heads of the tubes;
8. Store the tube bodies randomly bagged in bulk;
9. Deliver to tube filler; and, 10. Fill with product through the open bottom and seal that end.
The present invention can be advantageously applied between the above steps 5 to 6 and 9 to 10.
Background Art The printing of tube bodies requires randomly bagged tube bodies ( that is, without heads) of a single diameter and length to be aligned, and fed to support mandrels for printing. In doing this there is no need to orient them with either end fed front first. A machine which simply aligns and feeds the tubes, but does not differentiate in any way between the end of the tubes has been developed already and is capable of substantially unattended operation. The present invention is an enhancement of such a known type of machine having a number of new and useful features which
- 4 - enable the tubes not only to be aligned, but also to be identified for a desired leading end (hereinafter termed a polarity) when such has been imparted by a preceding manufacturing step. Further, the new machine detects a polarity with respect to one end of the top of the decoration and has means provided to reverse those tubes detected as having the undesired polarity after alignment. This reversal of direction is achieved with the advantage of not requiring the rejected tubes to be returned to the alignment section of the machine and therefore not being subjected to any more than the minimum amount of scuffing.
The already known device consists of a large horizontal disc of typically 1 to 1.2 metres diameter, rotatable about a vertical axis; the disc is overlain by a first vertical wall of sheet metal rolled into substantially a full circle of a diameter about 50 to 100 mm less than that of the rotating disc. This first wall is about 150 to 200 mm high and is assembled approximately concentrically with respect to the rotating disc by mounting it on a frame which holds the wall just clear of the upper surface of the disc. A second vertical wall generally similar to the first but shaped in circle generally concentric with the first wall and spaced apart from the first wall by an amount sufficient to allow the tubes to be driven with longitudinal axes in the direction of travel as imparted by the motion of the disc. The second or outer wall is in the form of substantially a full circle and is provided with an outlet point in the form of a cut out portion of the wall. Means can be provided to varu the distance between the guiding walls so that more than one tube diameter can be aligned and fed.
The above described, known alignment feeder
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receives tube bodies having random alignment (conveyed on demand from a bulk hopper) being dropped in the central region of the rotating disc. The unscrambled tube bodies in the central portion of the disc progress radially outwardly until restrained from further outward movement by contact with the inner vertical wall. A suitably shaped cut-out in the wall together with an inlet guide permits only tube bodies which have become aligned with their longitudinal axes tangential with respect to the disc to enter the guide path between the inner and outer vertical walls. They are then conveyed end-to-end to the point in the outer wall where they leave the outer periphery of the disc tangentially and become driven by a straight, driven, approximately horizontal belt conveyor. On this conveyor the tube alignment is preserved by guide walls similar to those around the rotating disc, the guide walls being supported just above and clear of the upper surface of the belt.
Disclosure of Invention The present invention is based on the above described known machine. It requires the prior imparting of a means of identifying the polarity of each tube with respect to the printed decoration. After initial alignment of the tubes, on the conveyor path, those of incorrect polarity are rejected from the outgoing conveyor. The apparatus provides a means of turning each rejected tube such that each will be returned, without further realignment, and thence conveyed onto a parallel path straight conveyor to be subsequently recombined into a single stream (if necessary) together with the stream of aligned tubes already having the desired orientation, that is, those not rejected from the outgoing conveyor on the first pass.
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In broad terms the invention can be said to consist of apparatus to feed and orientate a plurality of elongate articles, said apparatus comprising a substantially horizontal planar first disc (1) rotatable about a first central substantially vertical axis, a first circumferential guide path (6) formed between an inner and a middle cylindrical wall (3, 4) each substantially co-axial with said axis and overlying said first disc (l), an entry point (20) located in said inner wall (3) and leading into said first guide path (6) and an exit path (8) leading from said first guide path (6), characterised in that an outer cylindrical wall (5) substantialy co-axial with said axis and overlying said first disc (1) is provided to define a second circumferential guide path (9) between said middle and outer wall (4,5), an inspection station (13) located in said exit path (8) and having an ejecting means to discharge one of said articles at ejection location (16) onto a return path (22) overlying a substantially horizontal planar second disc (2) rotatable about a second central substantially vertical axis and leading into said second guide path (9), said second disc (2) having a peripheral portion located within said return path (22) and overlying a peripheral portion of said first disc within said second guide path (9) whereby said first and second discs rotate in opposite directions and aligned articles (15) moving along said exit path (8) but with an end-to-end orientation -with reference to external pre-applied marking- opposite to that desired, can be ejected at said ejection location (16) and passed to said second guide path (9) with the desired end-to-end orientation by the action of said return path (22).
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Brief Description of the Drawing A preferred embodiment of the present invention is more fully described with the aid of the accompanying Figure 1 which is a schematic unsealed plan view of the alignment and orientation device according to the present invention.
Detailed Description of the Preferred Embodiment A large disc 1 which can be rotated in a substantially horizontal plane in one direction about its central vertical axis, is closely overlain by three vertical walls 3, 4 and 5 of part circular form. These vertical walls define guided paths 6 and 9 in which aligned tubes such as 15 may travel.
The tubes to be aligned and orientated, having been already marked during the printing stage of manufacture by an eccentric encircling band of invisible ink which reflects ultra-violet light, are deposited, unaligned and unorientated, into the central region 7 of disc 1. The unsorted tubes tend to be driven generally toward the disc periphery as the disc is rotated continually, allowing those having a tangential alignment to the disc when in contact with the wall 3 to enter an entry point 20 in wall 3, becoming aligned and moving in guided path 6. They are conveyed around path 6 to point 17 where they leave the circular disc 1 tangentially, longitudinal axes remaining aligned to the direction of travel. As close as possible to the periphery of the disc 1 the tubes pass directly onto a flat conveyor belt 21 on which they continue to be driven by friction along exit path 8. At a convenient distance along path 8 each conveyed tube is caused to stop momentarily at inspection station 13 by a pair of indexed stops 11 and 12 engaging each tube in turn.
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At inspection position 13, an ultra-violet light beam is directed at a point on the halted tube where the encircling pre-applied UV light sensitive ink would be expected to be if the tube happened to be correctly oriented simultaneously with the.alignment step. The UV light beam works in conjunction with a sensing device capable of responding dependant upon the amount of light emitted or reflected from the target area of the tube. Whenever the undesired orientation is detected, which may be by means either of the presence or absence of the encircling band of UV light sensitive ink at the inspection location on the tube, a memory means in conjunction with a signal means causes an ejecting means at ejection location 16 to dislodge any tube having the undesired orientation off to one side of the guided path 8 when that tube is at position 16. those tubes when ejected roll onto a second rotating disc 2, rotating in the opposite direction to that of first disc 1. Suitable guides 18 and 19 define a return path 22 which in conjunction with disc 2 cause each tube ejected off the conveyor belt at 16 to pass through approximately 90 degrees of rotation of disc 2 onto a second guide path where the tube is once again conveyed by disc 1, this time around between guides 4 and 5 in second guide path 9. The plane of rotation of disc 2 is set above and just clear of that of disc 1 and their peripheries overlap approximately one tube diameter (a variable setting) -as illustrated in Figure 1.
In similar manner to that previously described, the tubes are conveyed around path 9 by the rotation of disc 1 until the guides 4 and 5 tangentially guide the tubes away from the disc to a point where the conveying of the tubes is resumed by the same conveyor belt 21 but this time travelling parallel to path 8.
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The tubes remaining on path 8 beyond ejection location 16 and all tubes on paths 9 and 10 will now possess the desired orientation. Depending on how many stations involved in the next operation the two parallel streams of oriented tubes may be reco bined to a single stream, allowed to remain in two streams, or further divided into more than two parallel streams as necessary, in each case using known indexing devices (not shown) .
Variations in the details of the device fall within the scope of the invention. As a further example of this, the number of inspection positions need not be limited to two if additional signalling time is required to achieve proper ejection. Likewise, the number of UV inspection detectors may be increased so that in the event of a tube not being correctly printed with the encircling band of UV sensitive ink, it may be positively rejected from the machine at an additional station provided to cover such a possibility. The larger disc may be formed such that the central region of it is formed higher in the centre than that portion coincident with the innermost guide path in order that tubes supplied to the central region may more readily proceed radially outwardly.
Advantages of the Invention
The proposed invention has the advantage of providing a faster feeding rate than unscrambler feeders which return articles having the undesired orientation back to the unscrambling section and for the same reason has the important additional advantage of minimising scuffing of the highly finished decorated tubes.