Patent Application
20090049867
The present invention relates to methods and devices for handling tubular knitted articles, in particular, although not exclusively, stockings and socks.
More specifically, the present invention relates to methods and devices which have the function of correctly orienting tubular articles picked up from a container in which they are placed randomly.
To produce stockings and socks, semi-finished tubular knitted articles are usually produced by either single or double cylinder circular knitting machines. The semi-finished article delivered from the circular machine has an elastic band at one end and an open toe at the opposite end. The open toe must be sewn or linked to form the closed toe of the finished tubular article. In some machines closing of the toe is performed using devices combined with the needles of the cylinder and/or of the dial of the machine. Nonetheless, this requires a specifically designed knitting machine, or a modification to existing machines.
When, on the other hand, the semi-finished articles are unloaded from the circular machine with the toe still open, a subsequent processing operation is required on each article, which consists of picking up the article and inserting it with the correct end, i.e. the end forming the open toe, into a linking or sewing machine. These operations to pick up the tubular articles, which have been placed randomly in a container, and position them on a tubular transport member or directly in the sewing or linking machine are conventionally performed by hand, resulting in labor costs having a high incidence on the finished product.
Machines have also been designed to allow these operations to be performed automatically.
For example, U.S. Pat. No. 5,040,475 describes complex machinery that picks up individual tubular articles from a container in which they have been placed randomly. By feeding the article along a specific processing path, detection means first detect the orientation of the tubular article along the feed path, recognizing whether the toe or the elastic band of the article is the leading end. After this has been detected, the tubular article is placed in an intermediate station, from which it is delivered in one direction or in the opposite direction according to the orientation with which it entered the station.
Therefore, when exiting the intermediate station the tubular article is always facing in the same direction (i.e. always with the toe being the leading end, or always with the elastic band being the leading end) to be then spread longitudinally and inserted over a transport tube which transfers the tubular article towards a sewing machine. This machinery is extremely complex and not very reliable.
JP-A-7468502 and JP-A-1272801 describe other appliances for handling tubular articles such as stockings or socks for the purpose of suitable orientation thereof.
U.S. Pat. No. 6,719,577 describes a device, which longitudinally orients individual tubular articles collected from a container, in which they are placed randomly.
EP-A-1221502 describes a device in which individual socks or other tubular articles are picked up from a container in which they are placed randomly and are then oriented so that they are always positioned with one of their ends facing forwards by means of a specific pneumatic path and using detection systems capable of distinguishing the elastic band from the toe of the article through different characteristics of elasticity of the fabric.
U.S. Pat. No. 5,769,286 describes a spreading device for longitudinally spreading socks or other tubular knitted articles.
EP-A-178143 describes a further system for detecting the orientation of a tubular textile article by distinguishing between the elastic band and the toe.
U.S. Pat. No. 5,511,501 describes complex machinery, which picks up individual tubular articles from a container in which they are placed randomly and separates them, placing each tubular article in a respective container of a smaller size. Subsequently, each article is picked up from the respective smaller container and fed to a specific pneumatic path inside which the tubular article is oriented so that it is delivered from the pneumatic path always with the same orientation.
U.S. Pat. No. 5,884,822 describes a further device and method for picking up individual tubular articles from a container.
U.S. Pat. No. 5,992,712 describes yet a further device for picking up individual tubular knitted articles and orienting them appropriately.
Similar problems regarding the orientation of tubular articles can be found when feeding stockings or socks to a pressing machine. For example, in the production of women's stockings, the problem exists of inserting each stocking, with the toe already sewn, over a pressing template and for this purpose the individual stockings must be picked up from a container in which they are placed randomly to be inserted over the form. Similar problems also occur in machines for packaging knitwear and hosiery articles, such as stockings and socks.
An object of the present invention is to provide a particularly simple, efficient and reliable device to perform orientation of tubular knitted articles, in particular, although not exclusively, stockings and socks, picked up from a container in which they are placed randomly, to be subsequently fed with the correct orientation towards machines, devices or instruments which perform the subsequent processing on said articles, for example and in particular (although not exclusively) sewing or linking of the toe, pressing or the like.
According to a different aspect, the object of the present invention is to provide a simple and effective method for correct orientation of tubular knitted articles, such as stockings and socks, picked up individually from a container in which they are placed randomly.
In substance, a first aspect of the present invention relates to a device for handling tubular knitted articles having a first end and a second end comprising in combination:
With an arrangement of this type it is unnecessary to perform detection on the tubular article while it is traveling along the feed path in order to subsequently perform orientation by inverting, if necessary, the direction of feed along the transport duct, as is the case in conventional devices. On the contrary, once the tubular article has been spread and the position of the end to be engaged for subsequent handling operations has been identified, one or other of the two pick-up members is actuated selectively.
In a particularly advantageous embodiment of the invention, the pick-up members are arranged and designed to engage each tubular article at the level of the first end of the tubular article, typically the elastic band, and to open it. It would also be possible for the pick-up members to be designed to engage the other end, i.e. the toe. The choice depends on the handling operations that must be performed on the tubular article in the subsequent processing steps. The edge at which the article is to be engaged is typically elastic when the article is a sock, but it must be understood that this edge could also be non-elastic, for example in the case of women's stockings or components of pantyhose. Moreover, the opposite end can be an open toe, when the function of the device is to feed (with the correct orientation) the articles to sewing or linking means. However, this second end could be a closed toe (sewn or linked), for example when the article is handled to be sent for pressing operations. In general, the device according to the invention is useful each time tubular articles having two structurally different ends are required to be fed in a predetermined direction to members, means, devices or machinery for further processing, said articles being picked up from a container in which they are placed randomly or in any case fed to the device with a random and undefined orientation.
In a practical embodiment, the device according to the invention includes an intermediate station, in which the tubular articles are positioned individually and in sequence in a substantially spread position, with the first and the second end approximately aligned with each other according to the longitudinal extension of the tubular article, said first and said second pick-up member being associated with said intermediate station. The detection means can in this case be advantageously arranged and designed to determine the orientation of the first and of the second end of the tubular article when it is in said intermediate station.
In a practical embodiment of the invention, the detection means are arranged and produced to detect whether said first end of the tubular article located in the intermediate station is positioned in proximity to the first or second pick-up member. Moreover, the pick-up members are controlled so that the tubular article is engaged at its first end by the first or second pick-up member at the level of which said first end is positioned.
Preferably, the detection means are optical means, capable of distinguishing and discerning the two ends of the tubular article from each other on the basis of the shape of the end. For example, the detection means can use a camera interfaced with an electronic processor, or in any case a control unit, equipped with image processing software. In a simpler version, the detection means can include an arrangement of photocells, such as a linear matrix or array, to identify the form of the end of the article which is interposed between the emitters and receivers of the photocells. Detection can be performed with the article at a standstill or with the article moving, on the basis of the sequence with which the photocells are intercepted by the article, said sequence being determined by the form of the article. For example, a linear matrix, i.e. a linear array of photocells can be provided, controlled by specific software capable of identifying with which temporal sequence the photocells are obscured when the article is gradually carried over them. This temporal sequence in fact depends on the shape, or form, of the contour of the article which in turn differs between edge and toe.
Notwithstanding the type of optical detection chosen, it is preferably configured so that the use of particular measures is not required on the articles, such as strips or bands of fabric in a different color to the body of the article, provided purely for the purpose of allowing discernment between the two ends. In fact, these measures cannot always be implemented due to the type of machinery used to produce the articles and, moreover, increase the cost of the article. Further, the device according to the present invention can still be used with detection means which make use of the aforesaid measures to allow recognition of the two ends.
Advantageously, a spreading system can be provided to longitudinally spread said tubular articles and longitudinally align the first and the second end of the articles. Advantageously, in this case the two pick-up members can be associated with the two ends of the spreading system.
According to an advantageous embodiment of the device according to the invention, the spreading device has an inlet for the tubular articles at one of its longitudinal ends and an outlet for the spread articles, which can appropriately be positioned on the side, so that the individual spread articles are delivered in a direction orthogonal to the direction in which they were inserted in the spreading member. The delivery direction of the tubular article from the spreading member is independent from the orientation of the article, which has not yet been identified.
The articles can advantageously be inserted in the spreading system by means of a pneumatic transport duct.
In a possible embodiment of the invention, a conveyor belt is combined with the spreading system to remove the individual tubular articles from said spreading system. This can define the base of an inner volume of said spreading system, the tubular articles being inserted in said inner volume.
According to a possible embodiment, each of the pick-up members has opposed engaging elements designed and controlled to engage and move opposite edges of textile material forming a corresponding end of the tubular article away from each other, to open said end.
According to a possible embodiment of the invention, a respective transfer device is associated with each pick-up member, arranged and designed to transfer a tubular article engaged by the respective pick-up member towards further manipulator members. These further manipulator members are designed and arranged to position each tubular article on a tubular transport member, either directly or after it has passed over a tubular reversing member.
The manipulator members can include a gripper which receives the tubular articles from one or other of said transfer devices. Advantageously, the transfer devices can each include a stretching member designed and arranged to be inserted into the open end of the tubular article, supported by a transfer member which moves the stretching member transferring it towards other manipulator members.
In a possible embodiment, each stretching member is supported by a respective slide actuated with translational motion, forming part of a respective transfer device.
In an improved embodiment of the invention, the pick-up members can be designed so as to directly perform transfer to further manipulator members, such as a gripper to load the tubular article onto a transport tube or the like.
In an advantageous embodiment, a single common stretching device can be associated with the two pick-up members. In this case, each tubular article is carried to the common stretching device, which can comprise mechanical or pneumatic, or combined mechanical and pneumatic engaging means. One or other of the pick-up members is then activated to pick up the tubular article, the end of which has been opened by the stretching device (which is preferably located in an intermediate position between the pick-up members) to transfer the tubular article towards other members, work stations or positions.
The invention also relates to a device for handling tubular knitted articles having a first end and a second end, comprising: an operating position; associated with the operating position, a first pick-up member and a second pick-up member for tubular articles which can be actuated alternatively to engage one or other of the two ends of the tubular articles.
The device can advantageously include detection means to determine the orientation of the first and of the second end of the tubular article, said first pick-up member and said second pick-up member being controlled to engage the tubular article alternatively, according to the orientation of the tubular article detected by said detection means, so that each tubular article is engaged always at the first end notwithstanding its orientation in the operating position. The detection means can be arranged and designed to determine the orientation of the tubular article when it is in the operating position. A control unit can be provided, programmed to receive information from said detection means and to control actuation of one or other of said first pick-up member and of said second pick-up member according to the information received from said detection means.
According to a further aspect, the invention relates to a device for handling tubular knitted articles, such as stockings or socks, with a first end and a second end, provided with two substantially symmetrical pick-up members which can be activated alternatively to engage one or the other of the ends of the article, in combination with detection means to determine the orientation of the article, so that the article is always engaged at one of the two ends by one or the other of the pick-up members, according to the detection implemented by the detection means. According to a possible embodiment, the pick-up members can each include a pair of fingers which can be inserted into the corresponding end of the tubular article. The end which is engaged by one or by the other of the pick-up members can, for example, the elastic edge of the article.
According to a possible embodiment, associated with the two pick-up members is a single common stretching device, that is, a member which opens, stretches or spreads the end of the tubular article to be engaged by the pick-up members. This common stretching device can have a pair of opposed engaging members, mechanical, pneumatic or a combination of mechanical and pneumatic, or of other suitable type, which are arranged and designed to engage and move apart opposite portions of an edge surrounding one or the other of the ends of the article. In a preferred embodiment, the common stretching device is arranged in an intermediate position between the stand-by positions of the pick-up members.
Besides being controlled to alternatively engage the tubular article (depending on how said article is oriented), so that said article is always engaged at the same end, the pick-up members can also be designed and controlled to transfer the tubular article thus engaged towards further manipulator members, such as a transfer device, a loading tube, a gripper for subsequent transfer to a loading tube, a manipulator to insert the tubular article onto an inspection, pressing or finishing template, or for other operations, such as those known in the field of manufacturing stockings, pantyhose, tights and other hosiery articles.
The tubular articles can be conveyed with any known means through various stations of which the device is composed, such as and typically a single or double spreading station, a reading station, a station where the ends are engaged. According to a particular and currently preferred embodiment, said transfer is obtained by arranging the tubular article transversely on a continuous conveyor, i.e. composed of a continuous member which moves along a closed path, such as a mat, a belt, a track, a plurality of slats joined to one another on a flexible belt or chain member, or the like.
According to another aspect, the invention concerns a method for handling tubular articles with a first end and a second end, comprising the steps of:
According to a possible embodiment, the method can include the following steps:
In a possible embodiment, the first end of the tubular article, typically the elastic band, is engaged and opened by the respective pick-up member. In another possible embodiment of the invention, the article can also be engaged at the toe and said toe can, for example, be opened.
According to another aspect the invention relates to a method for handling tubular articles with a first end and a second end, comprising the steps of:
The method can also include the steps of:
In an improved embodiment of the invention, the method also includes the steps of:
According to a possible embodiment of the method according to the invention, the first end of the tubular article can be engaged by a common stretching device, and one or the other of at least two pick-up members can be made to cooperate with said end, according to the orientation taken by the article in the work station.
The invention also relates to a device for handling tubular knitted articles having a first end and a second end, including: a working position; associated with said working position, a first pick-up member and a second pick-up member for the tubular articles, which pick-up members can be activated alternatively to engage one or the other of the two ends of the tubular articles. According to a possible embodiment the pick-up members are designed to open the ends of the tubular article which must be engaged by the pick-up member. In a further possible embodiment of the invention, the first pick-up member and the second pick-up member are combined with a common stretching device, which opens, i.e. stretches the end of the tubular article which must be subsequently engaged by the corresponding pick-up member.
According to an advantageous embodiment of the invention, the first and the second pick-up member in said working position are controlled to engage each tubular article in said working position always at the first end, which can be, for example, the edge or the toe of articles in the form of stockings or socks. The pick-up members are controlled so that they are always activated selectively and alternatively according to the orientation taken by the articles in the operating position. In practice, therefore, the invention consists of a device which by means of at least two pick-up members, engages each tubular article which is carried to a working position or workstation always at a same end, regardless of the random orientation with which said article is placed in the working position or workstation.
The pick-up member can be a member which also opens the tubular article at the end engaged by the pick-up member. In this case, a system to engage the tubular article can be associated with each pick-up member, to subsequently transfer said article to a different workstation. In another embodiment, this pick-up member can be composed of a member to engage the article once it has been stretched at the end thereof, for example by a common device in an intermediate position between the two pick-up members. The pick-up member can be composed of a mechanical member which also transfers the tubular article to a subsequent station.
Further advantageous embodiments of the method and of the device according to the invention are set forth in the appended dependent claims and will be described in greater detail with reference to possible non-limiting examples of embodiment of the invention.
The invention will now be better understood following the description and accompanying drawing, which shows a non-limiting practical embodiment of the invention. More specifically, in the drawing:
A device incorporating the present invention and which has the function of loading socks provided with an elastic band and an open toe onto a transport tube to convey the individual socks to a sewing machine is described below. However, it must be understood that the principles and the specific technical solutions described herein can also be utilized in other machinery, which handle, for example, tubular articles with a non-elastic open band and/or with the toe already sewn, for example to load the articles onto pressing templates, in a packaging machine, or the like.
In
Connected to the pneumatic transport duct 7 is a pneumatic return duct 11, which transfers, through an unloading device 13, any tubular articles which cannot be further handled, for example, when the pick-up device 5 due to an operating error picks up two tubular knitted articles simultaneously and feeds them to the pneumatic transport duct 7.
The numbers 105 and 111 indicate gate valves or valves used to open and close the individual branches of the pneumatic paths, and in particular the pneumatic duct 7 and the pneumatic return duct 11. The number 103 indicates a connection with a suction line, not shown, for example connected to a suction fan.
With reference to
In
The tubular reversing member 25 is employed, as will be more apparent below, when the individual tubular articles fed to the assembly of equipment 21 must be reversed to turn the finished tubular article inside out.
With specific reference to
The end 7B of the transport duct 7 terminates at a first end of a spreading device indicated as a whole with 27, inside which each tubular article fed through the pneumatic duct 7 is spread to position the first end (e.g. the elastic band) and the second end (e.g. the toe to be closed) of the tubular article aligned according to the longitudinal extension of the tubular article.
The internal structure of the spreading device 27 and its operating modes will be described in greater detail with reference to
A load-bearing structure 31, which also supports the spreading device 27 and the conveyor belt 29, supports a second conveyor belt 33 provided with a movement according to the double arrow f33 in a direction oriented substantially through 90° with respect to the direction f29 of the movement of the conveyor belt 29. The motor 35 (
The conveyor belt 33 is supported by side elements 37, to which the motor 35 is also fastened, which can move towards and away from each other with respect to the conveyor belt 29 below moving in the direction of the double arrow f37 for the purposes described below. The lifting and lowering movement of the side elements 37 is provided by an actuator 39 (
When an individual tubular article is delivered from the side of the spreading device 27 conveyed out of it by the conveyor belt 29, it must be transferred with a movement parallel to its longitudinal extension under a detection means to detect which of the two ends is the toe, or the elastic edge. In substance, the individual tubular article must be arranged at the level of at least one system capable of recognizing and distinguishing the two ends of the tubular article from each other. In the embodiment illustrated schematically here, the detection means include a camera 41 (represented schematically only in
Yet again, alternatively or in combination, a system capable of recognizing the presence of conductive materials, such as a metal thread, inserted in the band surrounding the toe of the tubular article to be closed, could be provided as detection means.
Yet again, alternatively or in combination, detection means could be provided which are based on recognition and discernment of the two ends of the tubular article through characteristics of elasticity, thickness, or of another nature, of said article.
Alternatively or in combination, in a preferred solution it would also be possible to use a system of photocells arranged according to a geometrical configuration which allows recognition of the form of the end of the article which is interposed between emitters and receiver of the photocell, to distinguish the elastic edge from the toe. Various types of devices having this functionality are known and those skilled in the art can easily select the most suitable detection or recognition device for the particular application.
In any case, the detection means can be single or double, i.e. present on only one side or on both sides of the conveyor belt 29, although to economize it would be preferably for them to be provided only on one side.
As the tubular knitted article, which is delivered from the side of spreading device 27, is positioned on the conveyor belt 29, it must be translated longitudinally to be taken with one of its ends, which has yet to be determined whether it is the toe or the elastic edge, to the level of the detection means 41. The transverse conveyor belt 33 positioned over the conveyor belt 29 has the function of translating the tubular article parallel to its longitudinal extension, according to the arrow f33, to take the end closest to the detection means 41 and under said means. To allow this translational movement of the tubular knitted article the surface of the conveyor belt 29 has a coefficient of friction at least slightly lower than the coefficient of friction of the conveyor belt 33, so that when the conveyor belt 33 is taken with its lower branch to press against the tubular article which is located on the conveyor belt 29, the movement imparted by the motor 35 to the conveyor belt 33 causes the tubular article to slide on the upper surface of the conveyor belt 29 until it is under the detection means 41.
It would also be possible to move the detection means 41 while the article remains at a standstill.
As mentioned, the purpose of these detection means 41 is to recognize whether the end of the tubular article positioned under them is the first end (e.g. the elastic band) or the second end (e.g. the toe), in order to communicate the effective orientation of the tubular article on the conveyor belt 29 to a central control unit (indicated schematically with 42 in
As the tubular article must be removed from the operating station or position, or intermediate station, in which the spreading device 27 and the conveyor belt 29 are located always with one of its ends being the leading end, i.e. always with the same orientation, for each tubular knitted article to be inserted over the tubular reversing member 25, or over the tubular transport member 23 always with the correct end, and typically with the elastic band, two groups of essentially symmetrical members 51A and 51B are arranged at the two sides of the conveyor belt 29, which are used to open and stretch the end of the tubular article to be subsequently inserted over one or over the other of the tubular members 23, 25. These groups 51A, 51B include pick-up and transfer members for the tubular articles. The one of said group or pick-up members 51A, 51B is actuated, at the level of which the end of the tubular article is positioned, which is to be opened and inserted over one or other of the members 23, 25. The members and the mechanisms forming the two symmetrical groups 51A, 51B are indicated with the same reference numbers followed by the letters A or B.
Each of the groups 51A, 51B firstly has a fixed suction surface 53A, 53B provided on a flat sliding surface 55A, 55B positioned along the side of the conveyor belt 29. Arranged over the suction surface 53B is a respective pick-up means 57A, 57B provided with a vertical movement imparted by an actuator 59A, 59B. The pick-up means 57A, 57B can thus move towards the corresponding suction surface 53A, 53B and away therefrom. The suction surface 53A, 53B and the corresponding pick-up means 57A, 57B with its actuator 59A, 59B form means to alternatively engage the elastic band, i.e. the first end of the tubular article which is brought over the suction surface 53A or 53B to open said end.
Each group 51A, 51B also includes a stretching device, composed in this embodiment of a pair of fingers 61A or 61B, In the
The two fingers 61A, 61B of each pair can be moved towards and away from each other by means of a piston-cylinder actuator 63A, 63B. The pair of fingers, with the respective actuator 61A, 63A or 61B, 63B, are supported on a support 65A or 65B movable vertically according to the double arrow f65 controlled by an actuator 67A or 67B (see in particular
The piston-cylinder actuator 67A or 67B is supported by a slider 69A, 69B. Integral with the slider is a rack 71A or 71B, meshing with which is a pinion 73A, or 73B, keyed on a shaft 75A or 75B, attached to the opposite end of which are the fingers 61A, 61B with the respective actuator 63A, 63B which moves them towards and away from each other. With this arrangement, a vertical lifting and lower movement of the support 65B or 65A controlled by the actuator 67B or 67A, besides a lifting and lowering movement of the respective fingers 61B, 61A, also causes rotation of the fingers about the axis of the corresponding shaft 75B, 75A.
The two sliders 69A and 69B are supported (see in particular
Each slide 77A, 77B in turn supports a guide 87A, 87B on which the respective slider 69A, 69B slides. This slider is provided with a movement according to the double arrow f69 in a direction orthogonal to the direction of the guide 79. This movement according to the arrow f69 is imparted to one or other of the two sliders 69A, 69B by a cam and tappet mechanism. This mechanism has a track which forms a cam profile 91, inside which two idle pins 93A, 93B, integral with respective sliders 69A, 69B, engage. The profile of the channel 91 is substantially symmetrical with respect to a vertical median plane and is configured so that a translational movement of one or other of the sliders 69A, 69B with their respective slides 77A, 77B in the direction of the arrow f61 from the position farthest from the median plane to the position closest to the median plane of the device causes the slider 69A, or 69B to move away with respect to the position of the spreading device 27.
With reference to the example in
The functions of the various movements described herein will be explained below with reference to an operating sequence of the entire device.
In the central zone of the box structure 150 the spreading device has movable pressers 161 actuated by actuators 163 (five in number in the example shown) which have the dual function, described in greater detail below with reference to an operating sequence, of reducing the cross section of the compartment or inner volume of the spreading device 27, reducing the vertical dimension, during the spreading step of the tubular article, and of allowing complete and correct spreading of said article also at its end which is inserted into the spreading device 27 first.
As can be seen in particular in
Alternatively, the screen 165 can be arranged on a surface approximately orthogonal to the direction from which the tubular articles are fed and the retention member can, for example, be composed of a gripper.
The box structure 150 is supported slidingly in the direction of the double arrow f150 to perform a transverse movement with respect to the direction of movement f29 of the conveyor belt 29. This transverse movement according to f150 of the box structure 150 of the spreading device 27 is imparted by a piston-cylinder actuator 171 and its purpose will be described with reference to an operating sequence of the machine.
Arranged in an intermediate position along the front of the conveyor belt 29 are the tubular members 23 and 25, the latter supported by a fixed structure 26, while the tubular member 23 is attached, for example, to a conveyor, not shown, of a machine which loads the tubular articles onto the sewing or linking machine.
At the level of the tubular members 23, 25 (which are superimposed and substantially coaxial with each other), is a gripper, indicated as a whole with 180, the function of which is to receive the individual tubular articles picked up from the pair of fingers 61A or 61B, stretch the elastic band and insert it alternatively over the upper tubular member 25 or over the lower tubular member 23.
The gripper 180 has a rotational movement through 180° around a vertical axis, imparted by means of a piston-cylinder actuator 183 supported by a slide 185 which also supports the gripper assembly 180. The piston-cylinder actuator 183 controls a rack 187 (see in particular
The slide 185 is provided with a vertical movement according to the double arrow f185 along a vertical guide 188. The vertical movement is obtained by means of a transmission belt 189 and a motor 190 arranged at the upper end of the guide 188. The movement according to the double arrow f185 allows the gripper to transfer the tubular article to the corresponding end of the tubular member 25 or 23.
The gripper 180 is composed of two flat jaws 201 supported by brackets 203. The two jaws 201 each cooperate externally with a pair of bars 205 which, as shall be apparent below, are used to block the elastic band of the tubular article on the jaws 201. The movement of the jaws 201 towards and away from each other is controlled by two piston-cylinder actuators 207, 209.
Operation of the entire machine described above is illustrated with specific reference to
An individual tubular article M is picked up by the pick-up device 5 from the rotating container 1 and sucked inside the pneumatic transport tube 7, which leads into the inner compartment of the spreading device 27. The suction that transports the tubular article from the inlet 7A of the pneumatic duct 7 inside the spreading device 27 is applied through the suction mouth 151.
In
By inverting suction inside the duct which connects in 7B with the inner compartment of the spreading device 27, the tubular article M is pulled and spread with a force applied by the air flow in the direction of the arrow F1 in
At this point, the tubular article M is in the spread position inside the volume of the spreading device 27. If two tubular articles are fed inside the spreading device 27 by error, the second tubular article will not be engaged by the retention member 167, thanks to the particularly narrow configuration of the end zone of the cuneiform volume defined by the screen 165 and will therefore be unloaded through the device 13 and the unloading duct 11 into the container 1 through inversion of suction. In fact, in this step suction inside the spreading device 27, a portion of the duct 7 and the pneumatic duct 11 is produced through the suction mouth 103, the gate valve 111 being open and the gate valve 105 being closed.
After the tubular article M has reached the spread position inside the volume 150 of the spreading device 27, the box structure of the spreading device is translated to the left (in the figure) by means of the piston-cylinder actuator 171 to take the position in
With the tubular article M engaged in this way against the upper surface of the conveyor belt 29, the box structure 150 of the spreading device 27 can be translated again from left to right (in the figure) by the actuator 171 to be returned to the position in
At the end of these operations the side panel 153 of the box structure 150 of the spreading device 27 is lifted by the actuator 155 and the conveyor belt 29 is actuated to transfer the spread tubular article out of the inner compartment of the spreading device 27.
In a subsequent step, not shown, the tubular article M is translated in a transverse direction with respect to the direction of feed of the conveyor belt 29, by means of the conveyor belt 33 until its end which entered the spreading device 27 last is under the camera 41 or other detection means arranged on one of the two sides of the conveyor belt 29. The camera is capable of distinguishing whether the end of the article under it (i.e. the end which entered the spreading device 27 last) is the toe or the elastic band of said article, i.e. if it is the second or the first end of the article.
As the article M must be engaged by pick-up means 53B, 57B or 53A, 57A at the level of its elastic band, according to the detection performed by the camera detection means 41 or other equivalent devices, the unit 28 controls the subsequent movement of the conveyor belts 33 and 29, which is coordinated to take the tubular article M with its elastic edge at the level of the pick-up means and in particular with its elastic band resting on the suction surface 53A or 53B.
Evidently, the tubular article M is in this way transferred from one or other of the symmetrical groups 51A, 51B according to the position of the elastic band, which is random as the tubular article is picked up from the container 1 in a random position.
If the tubular article M had entered the suction duct 7 with the opposite orientation, i.e. with the elastic edge B at the back and the toe P at the front, it would have been transferred with the elastic band B at the level of the group 51B. In the example illustrated the subsequent steps will be performed on the elastic band B by the group 51A. If the tubular article M had been facing in the opposite direction the group 51B would have been used instead, to perform the subsequent operations.
From the layout in
Once the band B has been engaged by the stretching fingers 61A, by means of the handling members described with specific reference to
When the fingers 61A are in the intermediate position they are placed above the gripper 180, as shown in the layout in
After reaching this position, also visible in the perspective view in
The overturning movement through 180 degrees which the gripper 180 can perform by means of the actuator 183 allows the mouth of the tubular article to be positioned facing the lower tubular member 23 (position in
When the tubular article M is fed from a double cylinder circular knitting machine it is already reversed, i.e. with its inner surface facing outwards. In this case the tubular article M is inserted directly onto the lower tubular transport member 23. If, on the other hand, the tubular article M is fed from a single cylinder circular machine, it must be reversed to take the surface normally on the inside to the outside before it is sewn. For this purpose, the gripper 180 rotates through 180° about the horizontal axis to insert the elastic edge B of the article over the upper tubular reversing member 25, which in a known way reverses the tubular article by means of additional members, not shown. The reversed tubular article is then transferred to the lower tubular transport member 23.
As will be clear from the description above of the structure and of the functions of the various members of the machine, it is capable of performing the following functions in parallel:
Therefore, three distinct tubular articles, on which the aforesaid operations are performed in succession, can be present at all times in the machine.
The members which spread the tubular articles longitudinally, detect their orientation and pick-up the end of the article to be handled are shown in
The suction duct 7 (
As in the embodiment shown in
The connector 7B leads into a compartment with a rectangular cross section 513 which has, at the opposite end with respect to the connector 7B, a shutter 515 having the function of modifying the conformation of the section of passage defined by the compartment 513, constricting it in a specific operating phase. The shutter 515 has a shutter element 515A controlled to translate according to the double arrow f515 orthogonal to the longitudinal axis of the compartment 513, by means of a piston-cylinder actuator or other suitable actuator shown at 517. As can be seen in particular in
Integral with the spreading system 510 is a suction mouth 521, connected to which is a suction duct 523, of which only the initial portion is shown in the drawing.
Cooperating with the spreading system 510 is a mechanism 525 to pick up the tubular articles which are sucked inside the spreading system 510 and which has the function of pulling each tubular article through the section of passage defined by the inner wall of the end portion 513A of the compartment 513 and by the shutter element 515A described above.
The mechanism 525 is supported by a slide 527, movable according to the double arrow f525 along a guide 529. Movement of the slide 527 is controlled by a belt 531 operated by a motor 533 and entrained around two pulleys. The mechanism 525 is constrained to the slide 527 by means of a piston-cylinder actuator 535 which controls the lifting and lowering movement in a vertical direction according to the double arrow f525X of the mechanism 525. The lifting and lowering movement of the mechanism 525 has the function of positioning said mechanism in line with the spreading system 510 and, alternatively, above the latter. This facilitates and improves the efficiency of flattening of the article when it is made to pass through the shutter 515, as the article is pulled against the shutter element 515A.
The mechanism 525 comprises an approximately box-shaped compartment 539, inside which a vacuum can be created by means of suction through an aperture 541 which is connected with a tubular connector 543 through a suction box 543A. The tubular connector 543 can be connected to the suction mouth 521 of the spreading system 510. This pneumatic connection is achieved by moving mechanism 525 along with its connector 543 according to the arrow f525 towards the suction mouth 521 and therefore towards the spreading system 5101, to make the elements 510, 525 take the reciprocal position shown in
Operation of the spreading system and of the relative mechanism 525 described above will be explained later on with reference to the detailed description of an operating cycle of the device.
In the station 509 is another spreading system 510X which has members equivalent to those described with reference to the spreading system 510, indicated in the figures with the same reference numbers followed by the letter X. The suction compartment 513X with rectangular section is connected to a suction duct indicated with 8B and corresponding to the suction duct 7B. As opposed to a mechanism like the one indicated with 525, the spreading system 510X located in station 509 cooperates with a simple conveyor belt or mat 563 supported by a supporting structure 565 of the device and provided with a movement according to f563 imparted by a motor 565. The conveyor belt 563 is driven about rollers which are supported, together with the motor 565 and the other members transmitting motion to the conveyor belt 563, by side panels 567 which move vertically by means of piston cylinder actuators 569, to allow the conveyor belt 563 to move towards or away from the conveyor 503. The conveyor belt 563 moves each individual article longitudinally, i.e. parallel to the extension thereof, in a transverse direction with respect to the direction of feed F of the conveyor belt 503 to take each tubular article inside the spreading system 510X and remove it gradually therefrom when the shutter element, equivalent to the shutter element 515A, is in the substantially closed position and suction continues through the slot it leaves open.
Downstream of the second spreading station 509 (with respect to the direction of feed F of the articles by conveyor 503) is a station 570 for detecting the ends of the tubular article. Located in this station is a presser 571, provided with a vertical lifting and lowering movement according to the double arrow f571 to press against the slats 503A forming the continuous conveyor 503, or to be lifted therefrom. The lifting and lowering movement of the presser 571 is controlled by an actuator 573 (
The presser 571 is positioned between two inclined profiles 581A, 581B which extend transversely to the direction of feed F of the articles, i.e. parallel to the slats 503 of the conveyor 503. The profiles 581A, 581B are supported by a cross-member 583, in turn supported by piston-cylinder actuators 585 interposed with the fixed structure 565. At the ends thereof, the cross member 583 supports actuator and guide systems 587, to which the profiles 581A, 581B are constrained, and which have the function of imparting a movement according to the double arrow f581 to the profiles 581A, 581B. In substance, the profiles 581A, 581B can be moved towards and away from each other. They have the function of centering each individual article which is positioned between the two profiles 581A, 581B.
At the station 570, located on the side of the conveyor 503 is a detection device which can comprise a camera, the images of which are processed by a suitable image recognition software, or a series of photocells or other means in general suitable to recognize, i.e. to distinguish the two ends of each tubular article inserted in the device from each other. This detection system is indicated generically with 590 in the figure, and can be supported by a C-shaped profile, which holds, for example, a series of photoemitters and an opposed series of photoreceivers, between which the end of each article closest to the sensor or detection device 590 is inserted.
To carry the article with the end thereof under the detection elements the previously described presser 571 is provided, and for this purpose it is lowered to press the article gently against the conveyor 503 and then, by translating horizontally (arrow f575), to take it to the desired position. This is made possible by the low coefficient of friction with which the slats 503A forming the conveyor 503 are produced.
In place of photocells, cameras or other optical reading systems, the detection device 590 can also use other mechanisms. For example, the two ends of each article could be made recognizable and distinguishable by inserting a specific material in only one and not the other of the two ends. For example, a metal yarn, a magnetic thread or the like could be inserted in one of the two ends (preferably the toe to be sewn when the articles being handled are stockings or socks). Recognition of these threads can take place with a capacitive sensor, a magnetic sensor or other suitable mechanism.
In general, the present invention is not limited to the type of reading or distinguishing mechanism to recognize and distinguish the two ends of each article from each other. However, and preferably, optical systems capable of recognizing and distinguishing the two ends on the basis of their geometrical conformation are used, as with these systems it is possible to avoid using special materials during production of the articles and therefore the device according to the invention can be more generally used and the manufacturing costs of the articles are reduced, by avoiding the need to carry out special procedures in the production steps upstream.
As can be seen in particular in
With this arrangement, once the article has been taken under the sensors or other detection members 590 and after the electronic control system of the device 501 has checked whether the end positioned under the detection systems 590 is the first or second end, with a horizontal movement of the presser 571 in one direction or the other, the article can be translated transversely with respect to the direction F of feed, to take the desired end to the apertures or slots 503C. This is the position the article must be in, to be able to proceed, in the subsequent station 600, with opening of the end of the article and consequently engage it by means of the engaging members of the station 600.
In practice, movement of the presser 571 is controlled so that the end of the article to be subsequently engaged by the pick-up members is always positioned on the apertures 503C. If the article to be handled is a sock, which must always be engaged at the elastic edge, movement of the presser 571 will be controlled to take said elastic edge to the perforated area 503C. If the elastic edge is the end recognized by the detection system 590, the presser 571 will move away from the detection system 590. Vice versa, if the end identified by the detection system 590 is the toe, this means that the opposite end must be taken to the perforated area 503C, and therefore the presser 571 will move in the opposite direction towards the detection system 590. If necessary, the presser 571 can perform several repeated movements, lifting up from the article between one movement and the next to avoid moving it in the wrong direction. Once the desired position has been reached with the end of the article over the perforated area 503C, suction can be activated to hold the article in position during the subsequent forward movement of the conveyor 503.
The first member found in the station 600 is a stretching device 601 (
Also fixed to the structure 565 in station 600 are the mechanisms and the devices forming the two pick-up members which are activated alternatively according to the orientation of the tubular article, to always engage the same end of the tubular article with one or other of said pick-up members. When this is, for example, a sock, the pick-up member which is correctly positioned to engage the elastic edge of said sock, forming the end previously stretched or opened by the stretching device 601, is activated. As the stretching device is disposed between the two pick-up members, it forms a common stretching device or member to cooperate alternatively with one or with the other of the two pick-up members. The opening of the edge will be oriented towards one or the other of the two sides of the conveyor 503 according to the orientation with which the article was delivered from the suction duct 7 (toe or edge facing forward).
The mechanical elements which form the first and the second pick-up member, and the relative actuators are shown in their movements in
In the station 600 a motor 611 is constrained to the fixed structure 565, which motor by means of a belt 613 supplies the movement to a splined bar 615, on which pulleys 617 are coupled. These pulleys are torsionally engaged with the splined bar 615 but can slide longitudinally along the axis thereof. The pulleys 617 supply the motion to respective belts 619, entrained around the pulleys 617 and also around further idle pulleys 621. The pulleys 621 are supported by slides 623 guided along a guide 624 integral with the load-bearing structure 565 and extending parallel to the splined bar 615.
The slides 623 can slide according to the double arrow f623. They are also constrained by supports 625 to the drive pulleys 617 torsionally engaged with the splined bar 615. Ultimately, therefore, the two belts 619 can move towards and away from each other and also move independently from each other according to the double arrow f623 in a direction orthogonal to the direction of feed F of the articles on the conveyor 503.
The movement of the individual slides 623 is controlled, independently for each slide, by a piston-cylinder actuator 627. Each of the actuators 627 is constrained to the load-bearing structure 565. Of these actuators, 627X indicates the rod which is rigidly constrained to the respective slide 623.
Reference number 631 indicates two pick-up members of the articles, each of which is supported by a slide 633 sliding along a guide 635 rigidly constrained to the corresponding slide 623. In substance, therefore, each of the slides 623 which translates orthogonally to the direction F of feed of the articles and of the conveyor 503, respectively supports one of the two pick-up members of the articles, each indicated with 631, movable parallel to the direction of feed F. Movement of the pick-up members 631 along the guides 635 is indicated in the drawing with the double arrow f631.
Each pick-up member 631 has a pair of brackets 637, each of which pivots about a respective horizontal axis 637A. A respective arm 639A, 639B is integral with each bracket 637. The pivoting movement of the brackets 637 is controlled by a piston-cylinder actuator 641 arranged in an intermediate position between two supporting side panels. Each of the arms 639A, 639B has, at the lower end thereof, hinged about respective pivoting axes, respective fingers 643A, 643B, The pivoting movement of the fingers 643A, 643B is controlled by a respective piston-cylinder 645A, 645B.
The oscillating movement of the arms 639A, 639B, in combination with the oscillating movements of the fingers 643A, 643B allows, as will be explained hereunder, insertion of the fingers 643A, 643B of one pair into the open end of a tubular article and subsequent engaging by said fingers of the end of said article. The moving apart motion the fingers of each pair causes transverse stretching of the ends of the tubular article.
A bracket 651 supporting a piston-cylinder actuator 653 is rigidly connected to each slide 633 supporting each pick-up member 631. The piston cylinder actuator 653 controls the oscillating movement according to double arrow f655 about a horizontal axis of a unit 655 which supports the tubular article engaged by one or other of the pick-up members 631. More specifically, the unit 655 constrained to one slide 633 cooperates with the unit 631 constrained to the opposite slide 633, as will be more apparent from the description of a complete operating cycle of the device.
The unit 655 has at the end thereof a gripper member 657, the function of which is to hold the tubular article in an intermediate area between the two ends to prevent it from interfering with other mechanical members when, by means of the pick-up member 631 which engages the first end thereof, said article is transferred e.g. to a pair of jaws 201 of subsequent manipulator members, for example to insert each tubular article onto a transport tube or the like. The jaws 201 are represented only schematically and separately from the rest in the figures described herein, and can be substantially the same as and have the same functions as the jaws 201 described with reference to
Having described the principal member of the device, the complete operating cycle thereof will now be described with reference to the sequence in
To spread the article M, at this point suction in the duct 7 is reversed and the article is sucked into the duct again. If by error two articles enter the compartment 513 simultaneously, one of them is unloaded back into the container 1, as the retaining pawl 547 is dimensioned so that it is unable to retain two articles M.
A similar process takes place for the opposite end (in this case the edge B) of the article in the station 509, as schematically illustrated in
In the station 570 (
In
To facilitate the subsequent operations of loading onto the jaw 201, the article M is engaged in an intermediate point of the longitudinal extension thereof by the gripper member 657 which is on the right (in the drawing). If the article M had been oriented in the opposite direction, the opposed gripper member 657 would have been activated.
Finally, the fingers 643A, 643B are made to pivot from the horizontal position to the vertical position (
It is understood that the drawing only shows an example provided as a practical embodiment of the invention, which may vary in forms and arrangements without however departing from the scope of the concept on which the invention is based. Any reference numbers in the appended claimed are provided to facilitate reading of the claims with reference to the description and to the drawing, and do not limit the scope of protection represented by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| IT2005/000496 | Aug 2005 | IT | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IT06/00191 | 3/24/2006 | WO | 00 | 5/23/2008 |
