TITLE METHOD AND APPARATUS FOR STEAMING ON FORMS HOSIERY ARTICLES AND THE LIKE
DESCRIPTION Field of the invention
The present invention relates to a method for steaming on forms hosiery articles and the like. The method applies to steaming and packaging lines of articles such as stockings, tights, knee socks, panty hose, leotards, socks and other articles, capable of being steamed automatically on forms.
Furthermore the invention relates to an apparatus that carries out this method. In particular, the invention relates to a machine with a plurality of forms on which the articles are loaded that are carried through a loading and shaping station, a steaming station, a drying station and finally an unloading station of the steamed articles for packaging them. Description of the prior art Automatic or semi-automatic machines are known that provide a step of loading the articles on forms arranged vertically on a carousel with several stations. The carousel brings in turn the forms to:
- a loading station, wherein the articles are loaded unstretched on the forms;
- a station of stretching the articles on the forms;
- a steaming station, where the forms and the articles on it loaded are steamed;
- a station of drying, in a chamber heated by air, - a station for unloading from the forms the articles dried and fixed.
To increase productivity and to let the tights stay longer on the forms, the carousel may have more
couples of forms than the number of stations, for example 8, 10, 12 and more.
The forms usually are arranged tangentially with respect to the carousel, even if in some locations of the path they are radial. Machines also exist that have forms arranged radially for all the stations or for large part of the path.
The articles are loaded on the forms in two steps. At first, they are loaded from the above on the forms in the loading station, in crumpled or unstretched condition. Then, in one or several following steps the articles are stretched on the forms by mechanical hands. Then, by means of mechanical fingers that move integrally to the forms, they are kept in position up to the unloading station.
The steaming step is critical when the forms enter the steaming chamber so that the article is steamed at a chosen temperature, that causes the relaxation of the fiber. The stretching of the fiber on the forms determines a better distribution of the tension of the relaxed fiber and of the article same. Furthermore, the anatomical profile of the forms is copied by the article.
The steaming chamber has walls containing the steam, an inlet and an outlet. The forms proceed tangentially following the trajectory of their bases in order to offer a minimum cross section when entering or leaving the chamber.
Problems of seal are critical at the base of the forms, since the supports are wide and often have on board bulky devices of rotation of the forms same.
In the machines with forms arranged radially on the carousel, in particular, the step of entering and leaving the steaming chamber is further complicated, since either the forms must rotate for orienting
tangentially themselves before entering, or the chamber must have a wide aperture.
In order to dry the steamed articles at the exit of the steaming chamber a drying chamber is normally provided with several stations. It is however necessary to define a closed space for containing the hot air delivered by radiating elements and to produce a drying flow. The definition of this closed space requires inner and outer walls in radial direction and ducts for recirculating the hot air.
Summary of the invention
It is therefore object of the present invention to provide a method for steaming on forms hosiery articles and the like, wherein the steam losses in the steaming chamber are reduced to the minimum.
It is another object of the present invention to provide such a method wherein the steaming chamber has dimension less than the known systems.
It is a further object of the present invention to provide such a method wherein forms arranged radially can be used without affecting the steps of entering and leaving the steaming chamber.
It is also object of the present invention to provide a machine for steaming on forms hosiery articles and the like that is capable of achieving the same objects.
It is a particular object of the present invention to provide such a machine wherein the articles are steamed on the forms in the steaming chamber without the need of complex devices integral to the forms same. It is another particular object of the present invention to provide such a steaming machine wherein a drying chamber is present of easy structure and wherein the air flow is most favourable.
According to a first aspect of the invention, a method for steaming hosiery articles and the like comprises the steps of:
- arranging a plurality of forms on a carousel rotatable about a driven axis, the forms being oriented radially with respect to the axis, a wall being present next to the forms that extends tangentially with respect to the axis;
- moving the forms through a plurality of stations one of which is a steaming station comprising a steaming chamber having a radial opening;
- moving radially the steaming chamber relatively with respect to the steaming station, so that the forms can move to the steaming station and can enter the steaming chamber through the radial opening; - ending the radial movement when the radial opening touches the wall and is sealed on it;
- supplying steam in the steaming chamber;
- radially moving the steaming chamber away from the wall freeing the forms in it present and allowing the rotation of the carousel.
According to another aspect of the invention, an apparatus for steaming hosiery articles and the like comprises :
- a carousel rotatable about a driven axis; - a plurality of forms arranged radially with respect to the axis along the boundary of the carousel, a wall being present next to the forms that extends tangentially with respect to the axis;
- a plurality of stations where the forms in turn are stopped ;
- a steaming chamber arranged in at least one of the stations and having a radial opening directed towards the wall;
- means for moving radially the steaming chamber, so that the forms enter the chamber through the radial opening, up to when the latter sealingly touches the wall, as well as for withdrawing the chamber at the end of steaming;
- means for introducing steam in the steaming chamber when that is sealingly closed against the wall.
In a preferred embodiment, the wall next to the forms that extends tangentially is a cylindrical wall integral to the carousel and to the forms.
Advantageously, on the cylindrical wall devices are mounted for holding the articles in a stretched position in the steaming chamber. Such devices, in particular for steaming tights, provide a mechanical finger that moves under the panties for holding them. Alternatively, in the case of stockings, socks or knee socks, such devices provide instead friction jaws.
The cylindrical wall can define a closed space in the carousel, this closed space being used as channel for ventilating hot air through the drying chamber.
Brief description of the drawings
Further characteristics and advantages of the method and of the apparatus according to the present invention, for steaming hosiery articles and the like, will be made clearer with the following description of an embodiment thereof, exemplifying but not limitative, with reference to the attached drawings wherein:
- figure 1 shows a top plan view of a steaming machine for stockings according to the invention with a plurality of couples of forms belonging to a carousel with several stations and arranged radially;
- figure 2 shows a partial view of the engagement/ disengagement of the steaming chamber with respect to the forms in the steaming station;
- figure 3 is an elevational view of the carousel of figure 1, cross sectioned according to arrows III-III of figure 1;
- figure 4 shows a partial plan view from below of the system actuating the translation of the steaming chamber;
- figure 5 is an elevational view of the carousel of figure 1, cross sectioned according to arrows V-V of figure 1;
Description of a preferred embodiment
With reference to figures 1, 3 and 5, an apparatus for steaming stockings and tights is formed by a carousel 1 rotatable about a central axis 2 with respect to a base frame 3.
To carousel 1 twelve couples of cantilever-like mounted forms 4 are radially connected that follow a circular trajectory indicated with a dotted line. Forms
4 have anatomical shape for leg and foot and are stiff enough to stand right towards the above.
The following are provided:
- a loading station 5 with a relative loading unit of the stockings that are going to be steamed on forms 4,
- a double station 6 for fitting the stockings on forms 4;
- a steaming station 7, having steam supplying means,
- an air drying station 8 that extends for about 180°, and
- an unloading station 9 of the steamed articles. According to the invention, carousel 1 is formed by a tubular body 10 (figure 3 and 5) with cylindrical wall 11, pivotally connected by means of bearings 12 to the base frame 3. The rotation of carousel 1 is obtained by means of a pinion gear 13 mounted to the base frame 3 by means of a support 14 and operated by a motor 15.
Forms 4 are mounted cantilever-like to wall 11 by means of cantilever arms 16. Stretching devices 17 are provided at the sides of arms 16, arranged between each
couple of forms 4 and suitable for holding the panties of the tights between the forms.
Wall 11, besides having the function of rotating the forms, has also the task of supporting radially the forms 4 by means of cantilever arms 16 so that they do not require supports arranged below, which are bulky and cause problems when entering the steaming chamber.
In the fitting station 6 (figure 1), devices are provided 18 and 19 of known type, and for this reason not described in detail, suitable for fitting the stockings and the panties when steaming panty hoses.
With reference to the steaming station 7, the steaming chamber, indicated with the numeral 20 (figure 2), has U-shaped cross section, with an opening 21 directed radially towards axis 2 and having seals 22. The chamber 20 is closed at the top and bottom where it is connected to flexible tubes 24 for feeding and discharging the steam (figure 3) . The chamber 20 is kept hanging on a guide and is moved by actuator arms 25, shown also in figure 4, articulated to crank arms 26. A vertical shaft 27 is integral to crank arms 26 and is pivotally connected to carousel 1 held by an axial bearing 28 at the base frame 3. A motor 29 operates the rotation of vertical shaft 27 thus causing crank arms 26 to rotate and then to reciprocate chamber 20 by means of actuating arm 25.
Steaming chamber 20 can move from a open position, indicated in figure 2 with a continuous line, to a closed position, indicated in figure 2 with a dotted line. In the open position steaming chamber 20 does not block the movement of forms 4 and allows their free rotation integrally to wall 11. In the closed position steaming chamber 20 fully incorporates the form 4 and its cantilever arm that is located in the steaming
station 7, and its opening 21 touches against wall 11, in order to prevent steam leaking by means of seals 22.
The cylindrical wall 11 has then the third function of providing a closure wall for steaming chamber 20. Furthermore wall 11 has a fourth function of supporting devices 30, one for each couple of forms 4, which operate mechanical fingers 31 that in some stations extend radially towards outside for supporting the article or for cooperating at loading. In particular when the articles are tights, mechanical fingers 31 hold the panties in the step of loading, for a fitting step by devices 18 and 19.
Alternatively, in the case of stockings, socks or knee socks, such devices provide friction jaws not shown. In any case, wall 11 that moves integrally to forms 4, can support a desired device that has, in one or more stations, functions that are auxiliary to the forms same, with the advantage that this device follows the forms without causing any obstruction. With reference to figure 1 and to figure 5, in drying stations 8 a drying chamber 40 is formed between doors 41 and wall 11. To base frame 3 five heating elements 42 are mounted that send hot air towards the above against forms 4 that are carried through chamber 40. Fans 43 re-circulate the air within tubular body 10 defined by wall 11, up to flow back to heating elements 42.
This way, wall 11 has the fifth function of defining drying chamber 40 and the sixth function of allowing hot air circulation without the need of specially provided ducts.
As shown in figure 3, the stockings (not shown) present in the unloading station 9 are drawn from the above in a way known by a carrying unit to rollers 45 not described in detail, since of known type. In this
case, stretching device 17 is divaricated and causes a disengagement of the stockings from forms 4 as well as an enlargement of the panties that allows a correct picking up of the stockings by unit 45. Finally, in figures 1 and 5 the loading unit 50, 51, 52, 53, 54, is shown as present in the station 5, which is also of known type and then not described in detail.
Notwithstanding reference has been made to an U shaped steaming chamber and to a cylindrical wall, obviously the concept underlying the invention may be extended without any further inventive effort to a steaming chamber formed differently by the movement of a chamber defining element against the wall. The chamber defining element may also be a door and the chambers may be defined by recesses formed by the wall and the door. In this case the forms may be mounted on cantilever arms inside the recesses and may be extended outside the recesses in the loading, fitting and unloading station, whereas they stay in the recesses in the steaming and drying station. The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.