Device for feeding yarn from a stack of multiple yarn feeders to a textile machine

Abstract

The present application relates to a device for feeding yarn from a stack of multiple yarn feeders to a textile machine. A device comprises at least one stack of feeders (F1, F2, F3), each feeder being provided with a motorized yarn winding reel (12) suitable for drawing yarn from a bobbin in order to feed it to the textile machine. The feeders (F1, F2, F3) are all electrically connected to a primary communication channel (32) for bidirectional communication with a central control unit (CU), the feeders (F1, F2, F3) being provided with electronic interconnection means (RXF, TXF) suitable for providing a secondary communication channel (34) which locally interconnects the stacked feeders (F1, F2, F3) with each other, and each feeder being programmed to transmit its own identification code (ID1, ID2, ID3) to the subsequent yarn feeders in the stack via the secondary communication channel (34).

Description

[0001] The invention relates to an apparatus for feeding yarn from a plurality of stacks of yarn feeders to a textile machine.

[0002] As is known, general purpose textile machines such as circular knitting machines may be fed by a plurality of yarn feeder devices.

[0003] One type of feeder, known as a positive feeder, is provided with a motorized reel on which the yarn is wound (e.g., 3 or 4 turns). By rotating the reel, the feeder extracts the yarn from the upstream spool and feeds it to the downstream textile machine. The local control unit can adjust the rotation rate of the reel based on the signal received by the voltage sensor, so as to keep the tension of the yarn substantially constant at the desired value.

[0004] EP 2664569 discloses a positive yarn feeder, which is suitable for being installed in a stacked configuration with other identical feeders. The yarn feeders are mechanically (e.g., by a screw or snap connection system) and electrically (by male and female connectors arranged on respective opposing interconnection surfaces of the yarn feeders) connected one above the other.

[0005] From an electronic point of view, the yarn feeders are all connected to a central control unit, which typically monitors and manages the coordinated operation of the individual yarn feeders via a linear bus (BUS) communication link (hereinafter referred to as "bus").

[0006] Each yarn feeder connected to the bus is provided with a unique identification code. This allows the central control unit to communicate only with any selected feeder.

[0007] Typically, the assignment of identification codes requires some manual operation by the operator. For example, after the numbering program is started, the operator presses buttons on the yarn feeders in the order corresponding to the desired numbers, and the desired numbers typically correspond to the positions of the yarn feeders in the stack.

[0008] This operation is not only susceptible to human error, but also requires a lot of time, especially considering that a textile machine may be fed by dozens of feeder stacks, each stack may contain, for example, 3, 4 or more feeders.

[0009] Besides this, it is also desirable to reduce the data flow on the bus during the weaving process, especially in error management steps (eg yarn breakage, sensor failure, etc.).

[0010] The object of the present invention is therefore to provide a device which allows the central control unit to automatically know the position of the feeders in the respective stack and to reduce the data flow on the bus during the weaving process, in particular in the error management steps.

[0011] This aim and other objects which will become more apparent as the description proceeds are achieved by a device having the features described in claim 1 , while the dependent claims describe other advantageous, albeit secondary, features of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention will now be described in more detail with reference to some preferred but non-exclusive embodiments of the invention, which are illustrated by way of non-limiting examples in the accompanying drawings, in which:

[0013] Figure 1 is a front view of a stack of yarn feeders belonging to an apparatus according to a first embodiment of the invention;

[0014] Figure 2 yes Figure 1 A block diagram of a stack of yarn feeders;

[0015] Figure 3 The central control unit is used to know the yarn feeder Figure 1 A block diagram of the program for the position in the stack;

[0016] Figure 4 is Figure 1 A block diagram of an error management procedure in a stack;

[0017] Figure 5 is a front view of a stack of yarn feeders belonging to an apparatus according to a second embodiment of the invention;

[0018] Figure 6 yes Figure 5 A block diagram of a stack of yarn feeders;

[0019] Figure 7 is Figure 5 A block diagram of an error management procedure in a stack;

[0020] Figure 8 is a block diagram of a stack of yarn feeders belonging to an apparatus according to a third embodiment of the present invention;

[0021] Fig. 9 is based on Figure 8 A block diagram of an error management procedure in a stack of an embodiment of the present invention;

[0022] Fig.10 Is based on Figure 8A block diagram of two yarn feeders stacked in an apparatus of an embodiment of the present invention;

[0023] Fig.11 The central control unit is used to know the yarn feeder Fig.10 A block diagram of the program with the position in the stack.

[0024] Figure 1 is a view of a stack 1 of positive yarn feeders 10 of the type to which the invention relates.

[0025] Each feeder 10 is provided with a motorized yarn winding reel 12. Yarn (not shown) is adapted to be wound between the reel 12 and the spacing pin 14 (e.g., 3 or 4 turns). By rotating the reel 12, the feeder 10 picks up the yarn from the upstream bobbin (not shown) through the first input yarn guide eyelet 15a and feeds it to the downstream textile machine (not shown) through the output yarn guide eyelet 15b.

[0026] The feeder 10 may be provided with a local control unit (not shown) adapted to adjust the rotation rate of the reel 12 based on a signal received from a tension sensor 16 arranged between the reel 12 and the output yarn guide eyelet 15b, thereby stabilizing the tension of the yarn supplied to the textile machine at a desired value.

[0027] Typically, feeders 10 are mechanically interconnected in a stacked configuration, such as by screws (not shown), and electrically interconnected by male and female connectors 20, 22 disposed on opposing interconnection surfaces 26 and 24 of feeders 10, respectively.

[0028] The feeder at the top of the stack 1 is connected to a terminal 28 provided with fixing means 30 for anchoring to a frame (not shown), which in the case of a circular knitting machine is typically an annular frame.

[0029] exist Figure 2 In the block diagram, Figure 1 The three feeders of the stack 1 are uniquely identified by respective reference signs F1 , F2 , F3 .

[0030] In a manner known per se, the feeders F1 , F2, F3 are all electrically connected via connectors 20, 22 to a main linear bus communication channel or bus 32 via which they communicate bidirectionally with the central control unit CU.

[0031] The central control unit CU monitors and manages the coordinated operation of the individual yarn feeders of the individual stacks.

[0032] According to the present invention, each of the feeders F1, F2, F3 is provided with an electronic interconnection device suitable for providing a secondary communication channel 34 (the secondary communication channel 34 locally interconnects the feeders F1, F2, F3 with each other), and is programmed to transmit its own identification code via the secondary communication channel 34 to the yarn feeder behind it in the stack.

[0033] In this specification, the term "follow" refers to an adjacent relationship between two feeders in a selected direction, which is valid for all feeders in a stack (ie, from the top feeder to the bottom feeder of the stack, or vice versa).

[0034] refer to Figure 1 On a practical level, the electronic interconnection device can be of optical type and can include an LED (light emitting diode) transmitter TXF located on one of the interface surfaces 24 and a receiving photodiode RXF aligned with the LED transmitter TXF and located on another interface surface 26, the other interface surface 26 being suitable for being adjacent to the first interface surface when the feeder 10 is in a stacked configuration.

[0035] Thus, in this embodiment, communication between feeders 10 via the secondary communication channel 34 is unidirectional.

[0036] Figure 3 is a schematic diagram of a procedure for the central control unit CU to learn the position of the feeders F1 , F2 , F3 in the stack.

[0037] exist Figure 3 Messages via the secondary communication channel 34 are represented by double lines, whereas messages from and for the control unit CU sent via the bus 32 are represented by a single solid line and a single dashed line, respectively.

[0038] In a first step 101, each of the yarn feeders F1, F2 and F3 transmits its own identification code ID1, ID2, ID3 via the secondary communication channel 34 to the yarn feeder following it in the stack.

[0039] In a second step 102, the central control unit CU asks each of the feeders F1, F2, F3 about the feeder preceding it with a corresponding message RQ1, RQ2, RQ3 via the bus 32. Each of the feeders F1, F2, F3 replies to the central control unit CU by transmitting the identification code ID1, ID2 of the feeder following it via the bus 32, except for the first feeder F1 at the top of the stack, which transmits a null signal NULL indicating the fact that there is no feeder preceding it.

[0040] For example, in order to globally control all the feeders in the stack in a given step of the weaving process, the central control unit CU has all the information necessary to determine the order in which the various feeders are arranged in the stack, upon learning the end of the program.

[0041] Figure 4 is a schematic diagram of an error management procedure by which the central control unit CU can automatically stop all feeders F1 , F2 , F3 in a stack after receiving an alarm signal from one of the feeders.

[0042] This procedure can only be carried out after the control unit CU has learned the position of the individual feeders in the respective stack, for example by means of the previously described and Figure 3 The acquisition is performed according to the acquisition procedure shown in .

[0043] In a first step 201, a feeder, for example the second feeder F2, transmits its own alarm state ALF2 to the central control unit CU via the bus 32. In a manner known per se, when the second yarn feeder F2 enters the alarm state, it stops automatically.

[0044] In a second step 202, the central control unit CU transmits stop commands STOP1, STOP3 to all other feeders F1 and F3 of the stack via the bus 32, making it easier for the operator to intervene in the second feeder F2. Feeders F1 and F3 again reply via the bus 32 with corresponding confirmation signals OK1 and OK3.

[0045] In a third step 203, the second yarn feeder F2 transmits its own all-clear status ALF2_END to the central control unit CU via the bus 32. In a manner known per se, once the alarm state is over, the second yarn feeder F2 automatically restarts. At this point, the central control unit CU transmits the start commands START1, START3 to the other yarn feeders F1 and F3 in the stack via the bus 32, and the feeders F1 and F3 again reply via the bus 32 with corresponding confirmation signals OK1 and OK3.

[0046] Figure 5 and Figure 6 An alternative embodiment of the present invention is shown, which differs from the previous embodiment in that the secondary communication channel 34' is bidirectional, that is, each of the yarn feeders F1', F2', F3' is capable of transmitting information to / receiving information from any one of two adjacent yarn feeders in the stack.

[0047] On a practical level, Figure 5As shown, a bidirectional secondary communication channel 34' can be provided by mounting an LED (light emitting diode) transmitter TXF' and a receiving photodiode RXF' on both interface surfaces 24', 26', obviously in inverted positions relative to each other.

[0048] In this embodiment, the procedure for learning the position of the yarn feeder within the stack can be performed in a manner similar to the previous embodiment.

[0049] Figure 7 An error management procedure is shown which directly disables all yarn feeders of the same stack when one of them enters an alarm state using the bidirectional secondary communication channel 34', without requiring intervention of the central control unit CU' via the bus 32'.

[0050] Therefore, the error management procedure can be executed even if the position learning procedure is not executed.

[0051] In particular, in a first step 301, a yarn feeder, for example the third feeder F3', transmits an alarm state ALF3' to the central control unit CU' via the bus 32'. In a manner known per se, when the third feeder F3' is in an alarm state, it stops automatically. The central control unit CU' stops the machine.

[0052] In a second step 302, the third feeder F3' transmits the alarm status ALF3' to an adjacent feeder (in this case the second feeder F2') via the secondary communication channel 34', which stops and transmits the alarm status ALF2' to an adjacent feeder (in this case the first feeder F1'), which in turn stops.

[0053] In a third step 303, the third feeder F3' transmits the cleared alarm state ALF3_END' to the central control unit CU' via the bus 32'. In a manner known per se, the third feeder F3' automatically restarts when the alarm state ceases. The central control unit CU' restarts the machine. At this point, via the secondary communication channel 34', the third feeder F3' transmits the cleared alarm state ALF3_END' to the adjacent feeder (in this case the second feeder F2'), which restarts, and transmits the cleared alarm state ALF2_END' to the adjacent feeder (in this case the first feeder F1'), which in turn restarts.

[0054] Figure 8Another embodiment of the present invention is shown, which differs from the previous embodiment in that the terminal M″ to which the feeder at the top of the stack is connected is provided with its own control unit for managing one or more sensors, for example, a yarn break sensor independent of the feeder (not shown), and the terminal M″ is also configured for bidirectional communication via a secondary communication channel 34″. In the example previously described, the terminal M″ can be provided with its own LED transmitter (not shown) to transmit data to the first yarn feeder F1″ of the stack, and with its own receiver photodiode (not shown) to receive data from the first yarn feeder F1″ in the case of a bidirectional connection.

[0055] Fig. 9 Involved Figure 8 An embodiment is shown, and an error management program is shown, which uses a secondary communication channel 34" to transmit the alarm state and the clear alarm state from the terminal M" to the stacked yarn feeders F1", F2", F3". This program can also be executed in the case of a unidirectional secondary communication channel.

[0056] In a first step 401, the terminal M″ transmits the alarm state ALS″ of the sensor to the first yarn feeder F1″ adjacent thereto in the stack via the secondary communication channel 34″.

[0057] In a second step 402, the first yarn feeder F1" enters an alarm state, stops and transmits the alarm state ALF1" to the central control unit CU" via the bus 32". The central control unit CU" stops the textile machine.

[0058] In the third step 403, the first yarn feeder F1″ transmits the alarm status ALF1″ to the second yarn feeder F2″ behind it in the stack. The second yarn feeder F2″ stops and transmits the alarm status ALF2″ to the third yarn feeder F3″ behind it in the stack via the secondary communication channel 34″, and advantageously transmits it to the central control unit CU″ via the bus 32″. The third yarn feeder F3″ stops and advantageously transmits the alarm status ALF3″ to the central control unit CU″ via the bus 32″.

[0059] In the fourth step 404, the terminal M″ transmits the sensor's alarm-released state ALS_END″ to the first yarn feeder F1″ in the stack via the secondary communication channel 34″. The first yarn feeder F1″ restarts and transmits the alarm-released state ALF1_END″ to the central control unit CU″ via the bus 32″, and to the second yarn feeder F2″ via the secondary communication channel 34″. The second yarn feeder F2″ restarts and transmits the alarm-released state ALF2_END″ to the third yarn feeder F3″ via the secondary communication channel 34″, and advantageously to the central control unit CU″ via the bus 32″. The third yarn feeder F3″ restarts and advantageously transmits the alarm-released state ALF3_END″ to the central control unit CU″ via the bus 32″.

[0060] One advantage of this solution is that, in the case of an alarm related to a sensor, the error indication is essentially close to the point where the error occurred, in this case before the feeder. In known solutions, for example, the sensors are all connected to a separate bus or communicate on a main bus, with no direct link between the sensor and the feeder. As is well known to those skilled in the art, this situation complicates the management of alarms in known solutions.

[0061] Fig.10 Two stacks Sa", Sb" of yarn feeders are shown, each having a corresponding terminal Ma", Mb" at the top, which are equipped to communicate via secondary communication channels 34a", 34b". Each stack Sa", Sb" consists of two yarn feeders F1a", F2a" and F1b", F2b", respectively. Each feeder is connected to a bus 32".

[0062] Fig.11 The procedure of the central control unit CU" for learning the positions of the yarn feeders F1a", F2a", and F1b", F2b" on the two stacks Sa", Sb" is shown.

[0063] In this embodiment of the invention, this procedure may be performed by storing a corresponding terminal identification code IDMa", IDMb" in each terminal Ma", Mb" on the corresponding stack Sa", Sb".

[0064] In the first step 501, the terminals Ma″, Mb″ transmit their identification codes IDMa″ and IDMb″ to the first yarn feeders F1a″ and F1b″ of the corresponding stacks Sa″ and Sb″ via the corresponding secondary communication channels 34a″ and 34b″. Then, the first yarn feeders F1a″ and F1b″ transmit their own identification codes IDF1a″ and IDF1b″ to the second yarn feeders F2a″ and F2b″ via the corresponding secondary communication channels 34a″ and 34b″.

[0065] In a second step 502, the central control unit CU″ asks all yarn feeders which one is ahead of them in order to connect them in a manner similar to that described in the first embodiment and Figure 3 to understand their position within the corresponding stack.

[0066] In a third step, the central control unit CU″ preferably renumbers all yarn feeders according to their position in the corresponding stacks, or according to the mode that best suits the specific application, for example, for the feeders in the first stack Sa″, they are renumbered as IDF1,1″ and IDF1,2″, and for the feeders in the second stack Sb″, they are renumbered as IDF2,1″ and IDF2,2″.

[0067] Of course, although for simplicity only two stacks are cited, each stack containing two feeders, the procedure is applicable to an unlimited number of stacks containing an unlimited number of feeders, within the limits set by the technology used.

[0068] In practice, it has been found that the device according to the invention fully achieves the intended aim and objects since it allows the central control unit to automatically know the position of the feeders in the respective stack, thus preventing the risk of human error and speeding up the start-up steps of the device.

[0069] According to the intended purpose and aim, data transmission via the secondary communication channel also allows reducing the data flow on the bus during the weaving process, in particular in error management steps.

[0070] Some preferred embodiments of the present invention have been described, but a person skilled in the art will of course be able to provide various modifications and variations within the scope of the appended claims.

[0071] In particular, as previously mentioned, the number of stacks and the number of feeders in each stack can vary widely depending on the application.

[0072] Furthermore, the secondary communication channels may use electronic interconnects other than the optical interconnects used in the examples described herein, including physical electronic connectors that may also be disposed, for example, on two opposing interface surfaces of the feeder for direct engagement when the stack is formed.

[0073] Additionally, the error management procedures described herein by way of example have the purpose of illustrating some possible practical applications of the device according to the invention. However, it will be appreciated that the secondary communication channel can be used to propagate any type of message within the stack, and therefore not only identification messages or alarm messages, but also messages relating to, for example, the setting of a feeder (e.g. so that all feeders of a stack can be set up in the same way), status messages, etc.

Claims

1. An apparatus for feeding yarn to a textile machine, comprising a stack of at least one yarn feeder, each yarn feeder being provided with a motorized yarn winding reel, said motorized yarn winding reel being adapted to draw yarn from a bobbin for feeding the yarn to the textile machine, said yarn feeders being all electrically connected to a main communication channel for bidirectional communication with a central control unit, characterized in that Each of the yarn feeders is provided with an electronic interconnection device adapted to provide a secondary communication channel, the secondary communication channel locally interconnecting the yarn feeders in the stack with each other, and each of the yarn feeders is programmed to transmit its own identification code to the yarn feeder behind it in the stack through the secondary communication channel, the electronic interconnection device being arranged on two opposing interface surfaces of the yarn feeders, the interface surfaces being adapted to abut against each other when the yarn feeders are in a stacked configuration, The central control unit is programmed to know the position of the yarn feeder within the corresponding stack, The central control unit is programmed so that when a yarn feeder transmits its own alarm state to the central control unit via the main communication channel, the central control unit transmits a stop command to all other yarn feeders of the stack via the main communication channel, and all other yarn feeders of the stack reply with corresponding confirmation signals via the main communication channel, and The central control unit is programmed so that when a yarn feeder transmits its own cleared alarm state to the central control unit via the main communication channel, the central control unit transmits a start command to all other yarn feeders in the stack via the main communication channel, and all other yarn feeders in the stack respond with corresponding confirmation signals via the main communication channel.

2. The device according to claim 1, characterized in that The secondary communication channel is unidirectional.

3. The device according to claim 1, characterized in that The secondary communication channel is bidirectional.

4. The device according to claim 1, characterized in that The electronic interconnect device includes an LED disposed on a first one of the interface surfaces and a receiving photodiode disposed on a second one of the interface surfaces.

5. A procedure for learning the position of a yarn feeder within a stack belonging to a device according to any one of claims 1 to 4, characterized in that The procedure comprises the following steps: - each of the yarn feeders transmits its own identification code to the yarn feeders following it in the stack via the secondary communication channel, - the central control unit asks each of the yarn feeders via the main communication channel which yarn feeder follows it in the stack, - Each of the yarn feeders, except the first yarn feeder at the top of the stack, replies to the central control unit by transmitting via the main communication channel the identification code of the yarn feeder behind it, the first yarn feeder transmitting a signal indicating the fact that there is no yarn feeder behind it.

6. An error management program for a device according to any one of claims 1 to 4, characterized in that: The error management procedure includes the following steps: - execute the procedure by which the central control unit learns the position of the yarn feeder within the corresponding stack, - when a yarn feeder communicates its own alarm state to the central control unit via the main communication channel, the central control unit transmits a stop command via the main communication channel to all other yarn feeders of the stack, which reply with corresponding confirmation signals via the main communication channel, - When a yarn feeder transmits its own cleared alarm state to the central control unit via the main communication channel, the central control unit transmits a start command to all other yarn feeders in the stack via the main communication channel, and all other yarn feeders in the stack reply with a corresponding confirmation signal via the main communication channel.

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