AUTOMATIC DEVICE TO INSERT STOCKINGS IN KNITTED- SEAMING-MACHINES .

DESCRIPTION

.The present invention relates to an automatic device for inserting stockings into knitted-seaming machines. It is known that the process for manufacturing men's, women' s and children' s socks and stockings involves producing with dedicated circular machines a semifinished item made up of a tubular element which is open both on the elastic side (from which knitting begins) and on the toe side, the latter being closed through a suitable knitted-seaming step which is car- ' ried out - as was said - with a knitted-seaming machines. As is generally known, the knitted-seaming step ends with the stocking being turned inside-out, since for aesthetic reasons seaming is carried out on the reverse in a pre-established position. Then some finishing steps have to be provided for, such as an automatic hot ironing step. The present invention mainly relates to the step in which the stocking is inserted onto a knitted-seaming machine, thus upstream from the station in which the toe is seamed. A first known type of knitted-seaming machines . in- volves manual loading of the stockings onto said ma-

chines. In further detail, stockings are conveyed from the knitting area to the knitted-seaming area for seaming the toe, for instance inside baskets, with handling means such as forklift trucks. Then one or more operators pick up the stocking manually and insert it into a slide in which conveyor chains travel which convey it towards the area in which the toe is seamed. It should be pointed out that the upper portion of the stocking is inserted into the slide, so that the portion to be seamed is easily accessible to the elements carrying out seaming.

The step of insertion into the slide between the conveyor chains is highly critical since the stocking should be positioned correctly so that seaming is ho- mogeneous, standardized for all stockings and the finished item thus has a good aesthetic appearance and a high quality.

However, such type of devices for inserting stockings onto knitted-seaming machines has the drawback of re- quiring much labor, which is quite relevant especially as far as costs are concerned and is crucial for the quality of the finished item. Due to the variability introduced by the human element the various stockings are often positioned in a slightly different manner and once they are seamed they are therefore slightly

different one from the other. Moreover, this manufacturing step is highly repetitive for operators and human intervention does not result in a particular value added also from an economic point of view. A further disadvantage consists in that, since the manufacturing steps downstream and upstream from the knitted-seaming step are more or less automated, the knitted-seaming step, which requires a large number of operators, can be a bottleneck. This results for in- stance in a more complicated management of the manufacturing process and in an increase of lead time and therefore of costs.

In order to overcome the drawbacks referred to above, automatic devices for loading stockings onto knitted- seaming machines were conceived. The automatic loading onto knitted-seaming machines occurs as a rule through a pick-and-place station and a loader. In particular, in the pick-and-place station the stocking is picked up and conveyed by means of air jets into a pipe frame inside which it is oriented. The stocking is then picked up by a loader which slips it onto a tubular mold on which a particular positioning is carried out, which is required for the automatic loading onto the knitted-seaming machine. In particular, both stocking orientation and positioning are carried out by sensor

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systems that detect specific features ^• of the item (such as notches made on the elastic area for instance) . The stocking is picked up from the tubular molds, which are generally located on a carousel, by automatic tongs for instance, which insert it onto the slide of. the knitted-seaming machine where it is hooked by the conveyor chains.

Also this type of insertion for stockings onto knitted-seaming machines has some drawbacks. First of all, human presence is always necessary since, as was said before, a correct insertion and positioning of the stockings onto the conveyor chains are quite difficult and delicate. As a consequence, there is quite a high- probability of obtaining non- compliant finished items.

Moreover, the step of positioning on the conveyor chains is very often controlled and managed by complex detection and control systems which significantly increase the cost of the machine and make its management more complicated.

The present invention aims at obviating the above drawbacks .

In particular, the present invention aims at proposing an automatic device for inserting stockings into knit- ^' ted-seaming machines which enables and ensures a cor-

rect loading of the stockings onto the- knitted-seaming machine, and which therefore allows to obtain high- quality, standardized finished items. A further aim of the invention is to provide an automatic device for inserting stockings into knitted-seaming machines which requires a small number of operators. Still another aim of the invention is to propose ^' an automatic device for inserting stockings into knitted-seaming machines which does not make the knitted-seaming step critLcal within the global stocking manufacturing process. A final aim of the invention is to propose an automatic device for inserting stockings into knitted- seaming machines which is easy to be carried out, cheap and easy to be managed and handled. These and other aims that will emerge from the following description are achieved according to the present invention by an automatic device for inserting stockings into knitted-seaming machines in accordance with the appended claims . The following contains to a merely indicative and non- limiting purpose the description of a preferred though not exclusive embodiment of an automatic device for inserting stockings into knitted-seaming machines according to the invention, as shown in the accompanying drawings, in which:

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- Figμre 1 shows a side view of an automatic device for inserting stockings into knitted-seaming machines _ according to the invention;

- Figure 2 shows a view from above of the device of Figure 1 in which the conveying means are in a first operating position;

- Figure 3 shows a view from above of the device of Figure 1 in which the conveying means are in a second operating position; - Figure 4 shows a side view of the device of Figure 1 in which the stocking is in a first position;

- Figure 5 shows a view from above of the device of Figure 1 in which the stocking and the conveying means are in a first operating position; - Figure 6 shows a view from above of the device of Figure 1 in which the stocking and the conveying means are in a second operating position.

Referring to the figures mentioned above, an automatic device 1 for inserting stockings 12 into knitted- seaming machines according to the invention comprises means 2 for conveying a stocking 12 along a seaming path I ₁ and loading means 10 designed to pick up the stocking 12 from a collecting station and joining a portion thereof to the conveying means 2 in a loading station 8. As a matter of fact, the conveying means 2

can be joined to a portion of the stocking 12 so that its upper portion 12a is seamed in a seaming station located along the seaming path 7. The device 1 is characterized in that at least one portion of the con- veying means 2 can be shifted in the loading station 8 so as to enable the coupling of the stocking 12 with the conveying means 2.

In particular, the device 1 according to the present invention is joined to a known knitted-seaming machine upstream from the seaming station and is designed to cooperate with a collecting station. Said collecting station is generally represented by the outlet of a pick-and-place device 1 with loader where the stocking 12 is suitably positioned and oriented in an automatic manner and then inserted onto the knitted-seaming machine .

According to the invention, the conveying means 2 comprise at least one pair of conveying elements 3 between which a stocking 12 portion is inserted (Figures 4, 5 and 6) . Advantageously, as can be seen in Figure 4, an upper portion 12a of the stocking 12 - i.e. the portion near the toe so as to make its seaming easier in the seaming station with known elements - is inserted between the conveying means 2. According to the invention., at least one portion 3a of at least one of

the conveying elements 3 of the pair can be shifted between a first position in which said conveying elements 3 are near one another and have basically parallel longitudinal axes 4 in order to convey the stock- ing 12 along the seaming path 7 (Figures 2 and 5) , and a second position in which the conveying elements 3 are away from one another so as to increase the space 5 between them, at least in said portion 3a, in order to make the insertion of the stocking 12 easier (Fi ^' g- ures 3 and 6) .

In a first execution variant of the device 1, at least one portion 3a of at least one conveying element 3 can be shifted between the first and second position in a basically perpendicular direction with respect to the conveying direction of the stocking 12 along the seaming path 7.

In a second execution variant, conversely, at least one portion 3a of at least one conveying elements 3 of the pair can be shifted between the first and second portion in an inclined direction with respect to the conveying direction of the stocking 12 along the seaming path 7. In this case, the two conveying elements 3 of the pair in the second position form a sort of V- shape whose opening is on the loading means 10, pre- cisely so as to make the insertion of the stocking 12

between said conveying elements 3 easier and to ensure its correct positioning.

It should be pointed out that, in case only a portion 3a of the conveying element can be shifted, said por- tion 3a is the one located in the loading station and designed to cooperate with the loading means 10. Advantageously, at least one portion 3a of either only one of the conveying elements 3 of the pair or of both elements can be shifted between the first and second position. Moreover, the conveying elements 3 can be shifted from the second to the first position when at least one stocking 12 portion is positioned in the space 5 between them by means of the loading means 10 (as can be inferred from Figure 6) . As was already said, the conveying means 2 can comprise at least two pairs of conveying elements 3 arranged along the seaming path 7 and designed to cooperate so as to convey the stocking 12. In this case, at least one of the conveying elements 3 of at least one of said pairs, preferably at least one portion 3a of at least one element 3 of the one cooperating with the loading means 10 in the loading station 8, is designed to be shifted between the first and second position. s a. rule, therefore, in case of only one pair of con-

veying elements 3 at least one portion 3a of either one conveying element 3 or of both elements 3 can be shifted between the first and second position. In case of more joined pairs of conveying elements 3, con- versely, at least one portion 3a of either one or of both the conveying elements 3 of the first pair, i.e. the one joined to the loading means 10 and cooperating with them, can be shifted between the two positions. However, the protected inventive idea is not limited to said pattern but includes all types of shift of the various conveying elements 3 of the various pairs between the two positions in order to make the insertion of the stocking 12 and its correct positioning between said conveying means 2 easier and to ensure a good quality seaming.

Preferably, the conveying elements 3 of each pair comprise conveyor chains 6. As an alternative, they can comprise conveyor belts. Still according to the invention, as can be inferred from the accompanying figures, the device 1 further comprises means 11 for shifting the conveying means 2 between the first and second position. Said means 11 can be represented for instance by hydraulic devices. Advantageously, the device 1 according to the present invention also comprises a slide 9 suitable to define

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the aforesaid seaming path 7 and to cooperate with the loading means 10 and with the conveying means 2. More to the point, in a preferred embodiment of the invention shown in the accompanying figures, the loading means 10 pick up the stocking 12 from the collecting station, insert it into the slide 9 and then reach the loading station 8 where they cooperate with the conveying means 2 in order to insert the stocking 12 between the first pair of conveying elements 3. The stocking 12 further remains preferably joined to said slide 9 for the whole seaming path 7 as far as the station getting out of the knitted-seaming machine where it generally gets into a device 1 which turns it inside-out. Preferably, the loading means 10 comprise tongs and can be shifted between the collecting station and the loading station 8. As -a rule, said means remain in the loading station 8 until the stocking 12 starts being shifted by means of the conveying elements 3 along the seaming path 7, thus ensuring its correct insertion and positioning.

The device 1 further comprises adjustment and control means acting at least upon the loading means 10, upon the conveying means 2 and upon the shifting means controlling their operation. Still according to the invention, the conveying means

2 can further comprise at least one pair of secondary conveying elements 3 (not shown) designed to cooperate with the conveying elements 3 so as to convey the stocking ^' 12 along at least one portion of the seaming path 7. Also the secondary conveying elements 3 preferably comprise conveyor belts 6.

The inventive idea protected by the present invention includes a knitted-seaming machine characterized in that it comprises at least one automatic device 1 for inserting stockings 12 as previously described, positioned upstream from the seaming station. . _r • The invention thus conceived can be subject to several changes and variants, all which fall within the inventive idea. Practically, any material or size can be used depending on the various needs .

All details can further be replaced by other technically equivalent elements. The invention has important advantages. First of all, a knitted-seaming machine having a device according to the invention requires only personnel with controlling tasks. As a consequence, there is a reduction as far as costs and manufacturing times are concerned and the item is no longer affected by the operator's sensibility.

The mobility of the conveying means further enables a stocking positioning which is always optimal and unchanged in time (at least until machine inputs are not changed in order to obtain different items) , and therefore a high quality of the finished item and a significant reduction of rejects.

A further advantage consists in that the device is not very expensive since it does not require complicated control systems or particular components. Finally, a knitted-seaming machine equipped with an automatic device for inserting stockings according to the invention has an effective operating interconnec- tivity with upstream and downstream steps with respect to the knitted-seaming step, thus making the manufac- turing process of the stockings fluid eliminating critical spots and optimizing manufacturing lead time.