WO2007138629A1

WO2007138629A1 - Pneumatic conveying device for articles

Info

Publication number: WO2007138629A1
Application number: PCT/IT2007/000361
Authority: WO
Inventors: Nerino Grassi; Antonio Magni
Original assignee: Golden Lady Co SpA
Current assignee: Golden Lady Co SpA
Priority date: 2006-05-31
Filing date: 2007-05-23
Publication date: 2007-12-06
Anticipated expiration: 2008-11-30
Also published as: ITFI20060133A1

Abstract

A pneumatic conveying device (5) for articles (M), in particular textile articles such as socks and the like, comprising: a pick-up member (7) movable inside a first duct (9); a second duct (11), extending between an inlet (11A) provided in the wall of the first duct (9) and a station (3) of a processing path of said article; the second duct (11) is connectable to a suction source to generate a conveying air flow from the first duct (9) towards said station (3). In front of the inlet (11A) of the second duct a blowing nozzle (13) is arranged, associated with openings (15) produced in the wall of said first duct (9), communicating with the outside of said first duct.

Description

"Pneumatic conveying device for articles"

DESCRIPTION Technical Field

The present invention relates to improvements to devices for conveying articles in production or conversion lines. More specifically, the invention relates to a pneumatic conveying device for flexible and elongated articles, for example textile articles such as stockings, socks or the like. State of the art

In many industrial fields and in particular in the knitwear and hosiery industry pneumatic systems are used to pick-up, handle and convey finished or semi-finished articles. In these systems the articles to be transferred, for example, from one to another of several processing stations are drawn by suction into conveying ducts or tubes in which, by means of a suction system, a conveying air flow is maintained. In the specific hosiery filed, to which however the present invention must not be considered limited, conveying systems of this type are known, for example, from EP-A-1.221.502, US-A-5.769.286, US-A-5.511.501 , US-A- 5.884.822, US-A-5.992.712, US-A-5.040.475, JP-A-1.272.801 , US-A- 3.129.573. These pneumatic systems are used, for example, to transfer semifinished articles from circular knitting machines towards collection areas, towards further handling stations, such as cutting-and-sewing machines, sewing machines or the like. Conveying systems are also used from containers to collect semi-finished articles to further processing stations. Object and summary of the invention

An object of the present invention is the production of a particularly efficient pneumatic conveying system, to be applied for example and in particular (but not exclusively) to convey flexible and elongated articles, such as stockings or socks. This and further objects and advantages, which shall be apparent to those skilled in the art by reading the text hereunder, are obtained in substance with a pneumatic conveying device for articles, in particular textile articles such as socks and the like, comprising: a pick-up member movable inside a first duct; and a second duct, extending between an inlet provided in the wall of _ _

said first duct and a station of a processing path of said article; said second duct being connectable to a suction source to generate a conveying air flow from the first duct towards said station; wherein in front of the inlet of the second duct there is disposed a blowing nozzle, associated with openings provided in the wall of said first duct, communicating with the outside of said first duct. The air blown through the nozzle draws air through the openings in the wall of the first duct and, as a result of the specific arrangement in front of the inlet of the second duct, particularly efficient insertion of the articles from the first to the second pneumatic conveying duct is obtained. According to an advantageous embodiment, the blowing nozzle is carried by the wall of the first duct and is surrounded by the openings in connection with the outside.

In a practical embodiment, the pick-up member is provided with a translational movement along a trajectory from a pick-up position to a release position of said articles, inside the first duct. The release position is disposed above the inlet of the second duct.

Further features and particularly advantageous embodiments of the invention are indicated in the appended claims and will be described with reference to a non-limiting embodiment of the invention. Brief description of the drawings

The present invention will be better understood by following the description and accompanying drawing, which shows a non-limiting practical embodiment of the invention. More specifically, in the drawing:

Figures 1 to 6 show a schematic section of a device according to the invention in successive operating steps;

Figure 7 shows a view of a detail according to the line VII-VII in Figure 6; and

Figure 8 shows a detailed and partly sectional view according to the line VIII-VIII in Figure 6. Detailed description of an embodiment of the invention

The example illustrated shows a pneumatic conveying device provided in particular to convey individual socks or other textile articles picked up from a container 1 , in which they lie randomly, to transfer them towards a processing station 3 which (in this example) is formed by an article spreading section, but _ _g _

which can be represented by any other processing, standby or other station of a manufacturing system for processing the aforesaid articles.

The articles, shown at M, are in substance picked up individually from the container 1 , which can advantageously rotate about an approximately vertical axis A-A, to be inserted in the pneumatic conveying device indicated as a whole with 5 and by means of said device they are conveyed to the station 3.

The device 5 comprises a movable pick-up member 7 provided with a translational reciprocating movement according to the double arrow f7 in a substantially vertical direction. The pick-up member 7 has at the lower end thereof a pick-up element 7A, which can be constituted by a mechanical member, such as a gripper (indicated schematically in the drawing), a pneumatic member or any other device suitable to pick up individual articles M from the container 1. The pick-up member is movable inside a first duct 9 by means of an actuator (not shown). The movement can be guided by sliding guides (also not shown) of a conventional type.

A second duct 11 with an inlet 11A in connection with the inside of the duct 9 extends between the first duct 9 inside which the pick-up member 7 moves and the station 3. The second duct 11 is connectable, in the manner to be described hereunder, to a suction source, for example a blower, a fan, a compressor or the like, to generate inside the duct 11 a conveying air flow from the inlet 11A towards the station 3, with which the pneumatic duct 11 is in fluid connection through an outlet 11 B.

In front of the inlet 11 A of the duct 11 , disposed at an opening 9A of the side wall of the duct 9, there is provided a blowing nozzle 13, i.e. a nozzle from which air is blown into the duct 9 at an adequate pressure, preferably above atmospheric pressure.

The nozzle 13 is preferably positioned in an approximately coaxial position with respect to the opening 9A of the duct 9 and consequently to the inlet 11 A of the duct 11. Said nozzle is surrounded by openings, holes or ports 15 produced in the wall of the duct 9. The openings 15 place the inside of the duct 9 in connection with the outside. When a pressurized air flow is generated through the nozzle 13, directed towards the inside of the duct 9 oriented against the inlet 11A of the duct 11, by means of Venturi effect an air flow is generated, drawn by suction from the outside towards the inside of the duct 9 through the openings 15. This combined flow of pressurized air from the nozzle 13 and air drawn by suction through the holes or openings 15, together with the suction through the duct 11 , increases the efficiency of suction of the articles M in the pneumatic conveying duct 11. In an intermediate position of the duct 11 there is disposed a further station 17 represented in this embodiment by a standby station, or by a sort of magazine that allows an article M to be prepared inside the conveying path between the basket 1 and the station 3, when the latter is occupied by an article previously picked up from the basket 1 and on which the processing operation for which the station 3 is intended is being performed.

The standby station 17 comprises an inlet 17A and an outlet 17B and extends inside the duct 11 , so that the articles M picked up from the basket or container 1 pass through the station 17, if necessary remaining therein for a certain period of time, to be subsequently fed to the station 3. At the inlet opening 17A and at the outlet opening 17B of the standby station 17 there are disposed respective inlet shutter 19A and outlet shutter 19B, having the function of opening and closing the inlet and the outlet of the station 17. The shutters 19A, 19B are in substance formed by sliders movable in a direction f19 transverse with respect to the direction of feed of the articles M inside the duct 11 , said movement being imparted by suitable actuators, for example piston-cylinder actuators, not shown to simplify the drawing and easy to design by those skilled in the art.

In practice, in the embodiment shown, the standby station 17 comprises, between the inlet 17A and the outlet 17B a standby volume 21 defined between the shutters 19A and 19B and surrounded by a tubular member 23 with a wall provided with a plurality of holes 23A (see in particular also Figure 8).

The tubular member 23 is in turn surrounded by an outer sleeve 25, which is also substantially tubular in shape, so that between the tubular member 23 and the sleeve 25 there is defined a space or volume 27with an annular cross section. This space 27 with an annular cross section is in turn in communication by means of a suction duct 29 with a suction source, not shown, which can be the same one that also generates the air flow in the section of suction duct 11 between the shutter 17B and the outlet 11B. When suction through the suction duct 29 is activated, it creates a vacuum pressure in the inner volume 21 of the standby station 17 due to the presence of the communication holes or ports 23A.

The space or volume 27 with an annular cross-section surrounding the tubular member 23 can, moreover, be placed in fluid communication with the outside through an opening 31 which can be intercepted, i.e. closed, by a valve 37.

In the example illustrated the processing station 3 has a hollow member 35 into which the articles M are individually drawn by suction to undergo a spreading operation. This operation takes place with the aid of a suction system through the end 35A and the end 35B of the hollow member 35. In brief, as the structure of the station 3 does not form the object of the present invention, the members disposed therein are formed by a movable element 39 controlled by an actuator 41 to modify the cross section for passage through the hollow member 35 and by a manipulator 43 having the function of engaging each individual article and drawing it out of the hollow member 35. The manipulator 43 has a screen 45 behind which there is positioned a suction chamber 57 connected by means of a flexible suction pipe 49 to a suction source, which can be the same one to which the opening 35A of the hollow member 35 and the suction duct 29 are connected. In front of the screen 45 there is disposed a retaining element 50 that holds the article during handling and the numeral 51 indicates an auxiliary retaining tooth. The numeral 53 indicates an actuator that imparts a lifting and lowering movement to the manipulator 43 according to the double arrow f43, while the numerals 55 and 57 indicate linear actuators that move the members 50 and 51 respectively.

Having described the mechanical structure of the device 5 and of the standby station 17 and processing station 3, the operation thereof will be illustrated hereunder with reference to the operating sequence represented in Figures 1 to 6. In Figure 1 the pick-up member 7 has been lowered to take the gripping end 7A thereof inside the basket or container 1 , to engage an article M.

With an upward stroke, the pick-up member 7 takes the individual article M inside the first duct 9. A sensor, shown schematically in Figure 2 only and represented here by way of example by an emitter 61 and receiver 63 pair of a - D - photocell, detects the passage of the article M and causes the upward movement of the pick-up member to stop when the lower end (in this case the band end B) of the article M has reached approximately the height at which the opening 9A of the duct 9 and the inlet 11 A of the duct 11 are positioned, such that the article is consequently placed in front of the nozzle 13.

The article must at this point be transferred inside the standby station 17. For this purpose, the shutter 19B closes the outlet 17B of the standby station 17 while the shutter 19A is in the open position. In this position suction through the suction duct 29 (arrow F) generates an air flow from the inside the duct 9, through the opening 9A and the inlet 11A of the duct 11 to the inside of the standby volume 21 of the standby station 17. The shutter 19B prevents the article M from exiting from the station 17.

According to the invention, while air is drawn by suction according to the arrow F through the suction duct 29, pressurized air is blown according to the arrow F1 through the nozzle 13 inside the duct 9 towards the opening 9A and the inlet 11 A of the suction duct 11. This flow of compressed air causes air to be drawn according to the arrows F2 from the outside through the openings or ports 15 in the wall of the duct 9. This combined effect substantially increases the speed with which the article M enters the interior of the duct 11 and is positioned in the standby compartment 21 of the standby station 17. The manipulator or gripping member 7A located at the end of the pick-up member 7 is suitably deactivated to allow the article M to be released into the air flow towards the inside of the duct 11.

In this first operating step the opening 31 of the standby station 17 is maintained closed by the valve 37 to prevent the air drawn by suction through the suction duct 29 from being drawn from the outside through the opening 31 instead of through the opening 9A of the duct 9.

To prevent the article from penetrating with excessive violence and consequently knocking with excessive force against the temporarily closed shutter 19B, the holes 23A are preferably only provided in an initial portion of the wall 23, while the portion of said wall that is nearest to the outlet 17B of the standby station 17 is without holes 23A.

In the subsequent operating step (Figure 4) the outlet shutter 19B is opened, the opening 31 is freed by opening the valve 37 and, maintaining the manipulator 43 in proximity to the hollow member 35, through a suction port 49A in connection with the flexible suction duct or tube 49, a conveying air flow F4 is generated to cause the article M to be drawn by suction from the standby volume 21 of the standby station 17 to the inside of the hollow member 35 and against the screen 45 of the manipulator member 43.

The air that generates the flow F4 is not drawn by suction through the inlet openings 17A, as the shutter 19A is closed. This allows the initial portion of the duct 11 , and consequently also the duct 9 to be isolated with respect to the standby station 17 and to the pneumatic path downstream thereof, so that a new article M1 can be picked up from the container or basket 1 and undergo the same operating cycle described above, while the article M in the station 3 undergoes the processing operations for which this station is intended.

In fact, in Figure 5 it can be seen how a second article M1 has been picked up by the pick-up member 7 and taken in front of the inlet 11A of the duct 11 to be drawn by the air flow F drawn by suction through the suction duct 29. Before starting suction through the suction duct 29 and blowing of compressed air through the nozzle 13, the outlet shutter 19B and the valve 37 are closed to obtain the desired air flow from the inlet 11A to the suction duct 29. In this step in the processing station 3 it is not necessary to generate suction through the duct 11 , as the article M is already in position and engaged by the retaining member 50. The station 3 performs flattening of the article M holding the edge thereof by means of the manipulator member 43, which moves away to regularly remove the article M from the hollow member 35 as shown in Figure 6. In this step a suction air flow F5 can be established inside the hollow member 35 through the opening 35A of said member. This suction does not involve the standby station 17 due to closing of the shutter 19B, but allows the article M to be maintained longitudinally in tension while it is gradually extracted from the station 3 and flattened by means of the element 39 which, for this purpose, has been lowered to narrow the section of passage of the hollow member 35 (Figure 6).

It is understood, therefore, that while the article M is processed in station 3 (which as mentioned can also have different functions and structures to those illustrated), a new article M1 is positioned in the standby station 17 which acts as magazine. The arrangement described therefore allows the rate of pick-up of semi-finished articles M by the pick-up member 7 inside the container 1 to be independent of the processing rate of the station 3. This function can also be implemented in the absence of the system It is understood that the drawing only shows an example provided by way of a practical arrangement of the invention, which can vary in forms and arrangement without however departing from the scope of the concept on which the invention is based. Any reference numerals in the appended claims are provided purely to facilitate reading of the claims with reference to the description and accompanying drawing, and do not limit the scope of protection represented by the claims.

Claims

_ _CLAIMS

1. A pneumatic conveying device for articles, in particular textile articles such as socks and the like, comprising: a pick-up member movable inside a first duct; - a second duct, extending between an inlet produced in the wall of said first duct and a station of a processing path of said article; said second duct being connectable to a suction source to generate a conveying air flow from the first duct towards said station; characterized in that in front of the inlet of said second duct a blowing nozzle is arranged, which is associated with openings provided in the wall of said first duct, communicating with the outside of said first duct.

2. Device as claimed in claim 1 , characterized in that said blowing nozzle is surrounded by said openings.

3. Device as claimed in claim 1 or 2, characterized in that said nozzle is carried by the wall of the first duct.

4. Device as claimed in claim 1 , 2 or 3, characterized in that said pickup member is provided with a translational movement along a trajectory from a pick-up position to a release position of said articles, the release position being arranged above the inlet of the second duct.

5. Device as claimed in one or more of the previous claims, characterized in that it comprises a sensor along said first duct, which generates a signal to control stopping of the pick-up member.

6. Device as claimed in one or more of the previous claims, characterized by an article-standby station along said processing path.

7. Device as claimed in claim 6, characterized in that said station comprises an inlet shutter and an outlet shutter, disposed in sequence along the processing path, between said inlet shutter and said outlet shutter a standby volume for said articles being defined.

8. Device as claimed in claim 7, characterized in that a suction duct leads into said standby volume to draw the article by suction inside said standby volume when the inlet shutter is open and the outlet shutter is closed.

9. Device as claimed in claim 7 or 8, characterized in that said standby volume communicates with the outside through a port provided with an opening and closing valve. _ _

10. Device as claimed in claim 8 and 9, characterized in that said opening and closing valve and said inlet and outlet shutters are controlled so that said valve opens to generate in said standby volume a flow delivered through said outlet shutter, said outlet shutter being open and said inlet shutter being closed.

11. Device as claimed in one or more of claims 8 to 10, characterized in that standby volume is defined inside a tubular member with a perforated wall, surrounded by an external sleeve, in fluid connection with said suction duct.

12. Device as claimed in claim 9 and 11, characterized in that said port is produced in said external sleeve.