GB2264920A - Shrink packaging ring-type items in a seamless tube - Google Patents

Description

1 1 1 - 2.264920 A method of and an apparatus for the portion-wise

packaging of small items stacked on a removable magazine rod The invention relates to a method of and an apparatus for the portion- wise packaging of small items stacked on a removable magazine rod, and in particular ring travellers for ring spinning frames, in a seamless shrinkable tube.

The packaging of stackable small items, particularly stacks of ring travellers, has so far mainly been carried out with manually operated tools. The reasons for this are manifold. The main cause lies above all in the exacting demands of the packaging of the stacks of ring travellers, the small size and the widely diverse sizes and shapes of ring travellers.

This is very time consuming and entails considerable cost and it is an extremely monotonou task for the workers. The exacting demands of the packaging arise mainly from the fact that while retaining the stack structure, it must be possible for the ring travellers to be fitted on the magazine rods of the ring inserting appliances easily, in the correct position and without loss.

These demands call for a precisely retainable simple technology for removal of the stacks of ring travellers from the packaging.

To date, this demand is satisfied only by packaging in a seamless shrinkable tube.

- 2 This endlessly produced seamless tube by virtue of its structure which is regularly orientated in the longitudinal direction, permits of a permanently repeatable tearing open of the tube along a surface line.

The positionally precise packaging of the stacks of ring travellers in an endless tube does however present considerable difficulty which is a hindrance to further mechanisation or even automation of this process.

Above all, the difficulties resided in guaranteeing precisely positioned insertion of the objects to be packaged, the stack of ring travellers, through the single accessible aperture in the endless tube against the direction in which this latter is being fed.

The necessary reliability of opening of the endless tube after separation of a packaged portion remained unresolved.

The automatic portion-wise packaging of other mainly larger objects in tube-like casings was accomplished mainly by means of endless strips of flat film.

The objects are continuously placed on the film strips. The edges of the film strip are folded laterally around the items to be packaged and are welded from above, preferably by ultrasound.

The resulting tube is shrunk onto the packaged items by heat and a portion is then cut off.

The application of this method is not suitable for the portion-wise packaging of stacks of ring travellers. In order to safeguard an allround stable packaging, relatively large empty portions have to be provided between the stacks of ring travellers. These empty portions are intended to ensure that during the shrinking process the length of the tube is sufficient to enclose securely even the outermost ring travellers of a stack.

So that this additional portion of tube can also be drawn onto the stack without any problems during the shrinking process, it is necessary during welding to secure the periphery of the tube in the empty portions as well, to the same degree as in those portions in which a stack is present.

The state of the art offers no solution to this problem.

A further reason why continuous packaging with a tube weldable during packaging has not become established lay in the fact that the inner structure of the flat film strips is not regularly orientated in the longitudinal direction, by reason of the method of production of the film.

Welding by ultrasound produces additional irregularities in the structure of the welded tube.

On account of these still considerable difficulties in the packaging of ring travellers in tubes, attempts have been made to package the ring travellers in so-called clips (DE-PS 3402402).

These traveller carriers are elongate hollow bodies of elastic material, open on one side and adapted to the profile of the ring travellers. The stack of ring travellers is inserted into the end of the clip while this latter is opened up at the same time and is then held by the elasticity of the clip. However, there are significant shortcomings to such storage of stacks of ring travellers.

The outside dimensions even in the case of ring travellers of the same size are subject to quite considerable variation on account of the tolerances in the shape and internal structure of the material used. The relatively minor tolerances in the size of the ring travellers mean that the legs of the clips actually fix only a few of the ring travellers in a stack by resilient clamping.

The result is that the ring travellers which are not fixed in the marginal zones slip out during transport or storage.

To avoid the ring travellers dropping out, attempts have been made to keep the travellers in the clip by applying a small sealing point, using varnish. However, this results in particles of varnish being deposited an the ring when the ring travellers are fitted onto the ring of the ring spinning frame, preventing the ring traveller from slipping.

on the other hand, traces of varnish remain clinging to the ring travellers. Given the working conditions of the ring traveller, these residues interfere with trouble-free functioning- The sliding conditions of the thread become altered.

This in turn has decidedly negative effects on the regularity of the yarn spun on the frame.

For this reason, the use of these clips has not so f ar become established and as already mentioned at the outset, ring traveller stacks are still predominantly packaged manually in seamless tubes.

The object of the invention is further to reduce the number of operations which have to be performed manually, saving on labour, reducing costs and at the same time guaranteeing the user-specific properties of use of the stacks of small items, particularly ring traveller magazines.

The invention provided method of and apparatus for the portion-wise packaging of small items which can be stacked on magazine rods in endless seamless tubes of shrinkable material and which can be carried out automatically.

According to the invention there is provided a method for the portionwise packaging of small items stacked on a removable magazine rod, particularly ring travellers for ring spinning frames, in a seamless shrinkable tube, comprising the steps of feeding the closed seamless tube in strip form to a slipping-on station, at least partly expanding the tube in the centre by means of an expanding mandrel which can be fitted onto the magazine rod while remaining constantly at the front end of the tube, gripping the tube along fold edges of the f ront end of the tube and drawing the tube over the magazine rod on which there is a stack of small items, cutting the tube at intervals corresponding to the length of the magazine rod and an amount for shrinkage and progressively heating each filled tube at least partly at a further working station whereat the tube is shrunk into place.

This method makes it possible for the endless tube stored on a roll in the minimum of space to be opened out and transported in a precisely defined manner, being thereby drawn over the stack present on the magazine rod.

It is also ensured that the additional shrinkage length ascertained from experience can be adjusted and cut off prior to shrinking without interrupting the opening-out of the tube.

The partial shrinkage of the tube from the base of the stack to the head permits an unhindered feeding of the additional shrinkage length to the actual shrinkage zone.

Preferably the small items are ring travellers which are stored and maintained in a correct positional orientation by means of a vibrator and a f eed wire and are then pushed one after another stack-wise onto successive presented magazine rods, the filled magazine rods being fed to the working stations for packaging. These measures makes it possible to automate the supply - 7 of magazine rods loaded with stacks of ring travellers.

The shrunk-on tube can be additionally cut off close to the end of the stack and provided with respective axial incisions at both stack ends. This assists in providing a clearly defined opening of the packaging.

The strip-like seamless tube can bear printing identifying the packaging and the most important parameters of the small items packed. This is of importance because ring travellers in particular often have to be used in different sizes which cannot be differentiated without a direct visual comparison.

In another aspect the invention provided an apparatus for the portionwise packaging of small items which can be stacked on a magazine rod, particularly ring travellers for ring spinning frames, in a seamless shrinkable tube, comprising a workpiece carrier in the form of a rotary indexing table carrying magazine rods at indexed intervals and defining working stations means for stacking the small items on the magazine rods, means for expanding and slipping the tube onto each filled magazine rod, means for cutting off the excess tube portion and - a for cutting the tube ends of the magazine and means for heating and shrinking the separate tube into place.

Other features of the invention and the most expedient alternative configurations of the working elements associated with the individual stations for the apparatus are described hereinafter.

The invention will be explained in greater detail hereinafter with reference to an example of embodiment shown in the accompanying drawings, in which:

Figure 1 is a diagrammatic view of an automatic station for the packaging of ring traveller magazines in seamless shrinkable tube portions; Figure 2 illustrates the basic structure of a ring traveller; Figure 3 shows the principle of the construction of a storage station for the magazine rod; Figure 4 shows the principle of the construction of a slip-on station; Figure 5 is a section taken on the line VV in Figure 4; 9 - Fig.6 shows the shrinking station; Fig.7 shows the cutting station, and Fig.8 shows the take-off station.

For the automatic packaging of ring traveller magazines, an automatic apparatus is used which is equipped with a stepwisely switchable rotary indexing table 9 to accommodate the magazine rods 1 (Fig. 1).

These magazine rods 1 are disposed with their heads pointing upwardly close to the periphery and at intervals corresponding to the indexing step.

Individual working stations A to E are rigidly positioned around the periphery of the rotary indexing table 9,. likewise at the same intervals as the indexing step.

At the storage station A, the magazine rod 1 is loaded with a stack 11 of ring travellers 111.

The second station, the slip-on station B, serves for slipping the endless tube 2 onto the magazine rod which is filled with a stack 11 of ring travellers 111 and cutting off the tube portion 24 necessary for one stack 11.

The third station is the so-called shrinking station C. It is used for shrinking the tube portion 4 onto the stack 11 and consists of a hot air source 71, a vertically displaceable ring nozzle 72 and a switch over valve 74 disposed in the feed line to the ring nozzle 72.

The fourth station, the cutting station D, is used for cutting off the excess tube and for cutting in the shrunken tube 25 at both ends of the stack 11 in a longitudinal direction.

The take-off station E is for removing the packed stack 11 from the magazine rod 1_ An additional station can be used for cleaning the surround of the magazine rod 1 and for checking its fixing on the rotary indexing table 9.

For better understanding of the problems of packaging, Fig. 2 shows a side view of a ring traveller 111. The size and shape of the ring travellers 111 vary considerably. Their greatest dimensions may be chosen between 3 and more than 20 mm.

The diagrammatic structure of the individual stations is shown in Figs. 3 to 8.

At the storage station A (Fig. 3), a per se known vibrator 13 conveys the ring travellers 111 one after another onto a guide wire 12- A controllable abutment 14 at the bottom end of the guide wire 12 maintains the accumulating stack of ring travellers 111 on the guide wire 12. When a magazine rod 1 is positioned coaxially below the end of the guide wire 12, a second controllable abutment 15 disposed at the stack height above the first abutment 14, is moved into an active position. It holds the ring travellers 111 back above the stack 11 when the bottom abutment 14 is withdrawn. The stack 11 lowers onto the magazine rod 1.

When this has taken place, the abutment 14 moves back into its active position and the abutment 15 releases the stack which has accumulated above so that it can drop down onto the abutment 14.

The process is repeated in cadence with the packaging machine.

At the slip-on station, there is a storage means for the packaging tube hereinafter referred to as the tube 2. The storage means is a roll 3.

The front end of the tube 2 carries an expanding mandrel 4 and is held by guide means 41.

The grippers 6 which bring about the intermittent transport of the tube 2 are adapted to be raised and lowered by at least the length of the magazine rod 1 by a drive device 64 on a separate guide 63 for the gripper mountings.

The guide means 41 for the front end of the tube 21 and the expanding mandrel 4 are aligned substantially crosswise to the plane of the strip of tube 21.

A plate 42 which can be raised and lowered in its entirety serves as a support for the expanding mandrel 4, while a clamping member 43, by means of springs 44, presses the expanding mandrel 4 over the tube 2 and against the plate 42.

These guide means 41... 44 are generally in a stable and f ixed position. Since it is nec essary for the tube 2 which is pushed onto the stack 11 of ring travellers to be longer than the magazine rod 1, in order to allow the reserve length needed for the shrinking process, the plate 42 with the guide means 41 is raised by a lifting device 45 before a separating device 5 fixed to the guide means 41 cuts off the partially expanded tube portion 24 in the region of the expanding mandrel 4.

Once the tube portion 24 has been cut off to the predetermined length, the guide means 41... 44 raise the expanding mandrel out of the cut-off tube portion 24 and the rotary indexing table 9 is moved farther on. A fresh magazine rod 1 with a stack 11 of ring travellers is again positioned under the expanding mandrel 4.

12 - The drive device 45 lowers the guide means 41... 44 with tube 2 and expanding mandrel 4 onto the head of this magazine rod 1 and the progress of slipping-on recommences, the grippers being incorporated.

By way of further explanation, Fig. 5 shows a horizontal cross-section through the working elements of the expanding station. The drawing shows how the grippers 6 engage the fold edges 23 for transporting the tube 2 and show that the expanding mandrel 4 only opens out the middle portion 22 of the tube.

Fig. 6 shows the shrinking station C. The hot air source 71 with its feed line to the ring nozzle 72 and the switch-over valve 74 is held in the upper position during packing of the magazine rods 1. When the magazine rod 1 with the tube portion 24 slipped over it reaches this station, the ring jet 72, usually together with the hot air source 71 and the switchover valve 74, is moved vertically downwardly by a lifting device 73.

In the lower position, the switch-over valve is so switched that the stream of hot air is directed onto the tube portion 24 via the ring jet 74.

At the same time, the hot air source 71 is moved slowly upwardly with the ring jet 74 and thus the tube portion 24 is partially shrunk onto the stack 11.

By the movement from the base to the head part of the stack 11, the additional necessary shrinkage length of the tube portion is easily drawn over the top part of the stack 11.

When the ring jet 74 has reached the head level of the magazine rod, also the upper piece of the tube portion, now 25, is shrunk down to the diameter of the magazine rod 1 so that also the upper ring travellers 111 in a stack 11 are securely held.

The retention of the lower ring travellers is ensured in that the stack 11 of ring trave-1lers is supported on a very narrow abutment and the tube portion 24 also engages around this abutment. At the onset of shrinkage, therefore, also the bottom ring travellers are formlockingly held.

At the next station - referred to as the cutting station D - then, three different knives 81, 82, 83 are disposed and each has its own drive. The knife 81 cuts off close to the top edge of the stack that portion of the tube which still protrudes beyond the magazine rod.

A cutting device 82 provides the top end of the shrunk tube portion 25 with a notch. The cutting device 83 does this at the bottom.

Both notches serves to allow removal of the stack 11 or individual ring travellers from the packaged stack by simple means.

As has already been stated in detail in the preamble to the description, the effortless and tidy removal of the shrunk-on tube from the stack 11 is one of the main arguments in favour of the present invention.

This tube 2 which here serves as a basis of the packaging is seamlessly manufactured and has an emphatically longitudinally orientated structure, i.e. when torn, the tear will in all probability always propagate itself along a surface line of the tube 2 so that the notches provided here at this working station permit in the region of the opening of the ring travellers and accurate and tidy withdrawal of either the ring traveller stack 11 or of individual ring travellers 111 without visual contact and in a one-handed process.

There is absolutely no possibility of the ring travellers 111 falling out of the marginal areas of the stack 11.

At the following station - the take-off station E - then, only an abutment is needed which can be raised by a drive. This lifts the packaged ring traveller magazine off the magazine rod and conveys it on to further processing or packaging.

The distribution of the working functions over the individual stations may differ from that which has been outlined. What is essential is that the working functions can be carried out in the working cadence without hindrance to one another.

Vital to the distribution of the working functions is also the space which is available.

Shown as the cutting elements are knives which as a rule can be driven. It is readily possible instead of these knives also to use heated wires, laser beams or the like. The state of the art offers a wide range of possibilities in this respect.

Shown here as a hot air source 71 is a hot air pistol such as is usually commercially available. It is however entirely possible to use for the purpose different means such as for instance burners.

It is expedient for the hot air, after it has passed over the tilbe, or for the stream of hot air initially passed out into the open, to be returned to the heating process, after which the air is reheated and used again f or the shrinking process.

16 - List of reference numerals used 1 11 ill 12 13 2 21 22 23 24 25 26 3 4 41 42 43 44 45 6 61 62 63 64 Magazine rod Ring traveller stack Ring traveller Guide wire VibraIL-or Tube Tube, strip-like Tube, Tube, fold edges Tube portion, cut off Tube portion, shrunk Tube portion, notched expanded portion Roll Expanding mandrel Guide mans Plate Clamping member Springs Lifting device Cutting-off device Grippers Gripper jaw, movable Drive for jaw Guide for gripper mountings Drive device for gripper mountings 17 - 7 71 72 73 74 75 81 82 83 B D Hot air stream Hot air source Ring jet Lifting device Switch-over valve Dispersal pipe Cutting device (magazine length) Cutting device (top notch) Cutting device (bottom notch) Rotary indexing table Storage station Slipping-on station Shrinking station Cutting station Take-off station

Claims (10)

1. A method for the portion-wise packaging of small items stacked on a removable magazine rod, particularly ring travellers for ring spinning frames, in a seamless shrinkable tube, comprising the steps of feeding the seamless tube in strip form to a slipping-on station, at least partly expanding the tube in the centre by means of an expanding mandrel which can be fitted onto the magazine rod while remaining constantly at the front end of the tube, gripping the tube along f old edges of the f ront end of the tube and drawing the tube over the magazine rod on which there is a stack of small items, cutting the tube at intervals corresponding to the length of the magazine rod and an amount for shrinkage and progressively heading each filled tube at least partly at a further working station whereat the tube is shrunk into place.

2. A method according to Claim 1, wherein the small items are ring travellers which are stored and maintained in a correct positional orientation by means of a vibrator and a f eed wire, the ring travellers are pushed one after another stack-wise onto successive presented magazine rods, and the filled magazine rods are 1 19 - fed to the working stations for packaging.

3. A method according to Claim 1 or 2, wherein that the shrunk-on tube is also cut again close to the end of the stack and is provided with respective axial incisions at both stack ends.

4. A method according to any one of Claims 1 to 3, wherein that the strip form tube is printed with means of identifying the small items to be packed.

5. A method of packaging substantially as described with reference to, and as illustrated in any one or more of the Figures of the accompanying drawings.

6. An apparatus for the portion-wise packaging of small items which can be stacked on a magazine rod, particularly ring travellers for ring spinning frames, in a seamless shrinkable tube, comprising a workpiece carrier in the form of a rotary indexing table carrying magazine rods at indexed intervals and defining working stations, means for stacking the small items on the magazine rods, means for expanding and slipping the tube onto each filled magazine rod, means for cutting off the excess tube portion and for cutting the tube ends of the magazine and means for heating and shrinking the separate 1 tubes into place.

7. An apparatus according to Claim 6 and further comprising a vibrator for arranging the small items on a guide wire which leads downwardly to the head of each magazine rod positioned at the appropriate working station and at a distance from each other corresponding to the height of the stack and controllable supports for positioning the stack.

8. An apparatus according to Claim 6 or 7, wherein the means for slipping the tube onto the filled magazine rod consists of an expanding device with an expanding mandrel which constantly remains at a front end of the tube and the diameter of which is slightly greater than the maximum stack diameter and which bears elastically on the tube cross-wise to the plane of the tube strip, guide means with a lifting device for caaxially placing the mandrel on the magazine rod and which in the plane of the strip of tube has controllable grippers for gripping fold edges of the tube and a drive device for imparting a reversible lifting movement to the device and controllable parting or cutting means connected to the guide means acting as the cutting means for severing the v 21 - tube.

An apparatus according to any one of Claims 6 to 8 wherein the means f or heating and shrinking-on the tube portion comprises a hot air source, a ring jet displaceable parallel with the magazine rod and a controllable switch-over valve disposed in the air line between the hot air source and ring jet.

10. Packaging apparatus substantially as described herein with reference to and as illustrated in any one or more of the Figures of the accompanying drawings.