PRIORITY DOCUMENTS

[0001] The present application claims priority from Australian Provisional Patent Application No. 2020904228 titled “CORD DISPENSING APPARATUS” and filed on 16 November 2020, the content of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to cord dispensing apparatus. In a particular form the present disclosure relates to an apparatus for dispensing elastic cord to production line machinery.

BACKGROUND

[0003] The COVID-19 pandemic has resulted in an immediate and ongoing need for large quantities of disposable personal protective equipment (PPE) surgical masks to prevent the spread of infection, particularly for healthcare workers and others interacting with potentially infected and infected patients.

[0004] Disposable PPE face masks can be manufactured on production line machinery. Multiple layers of material are fed into production line machinery which cuts, folds, and ultrasonically welds the layers together to form a mask section. Typically disposable PPE masks are made of non-woven materials which provide fluid repellent/resistant properties such as polypropylene (PP), polyester, or polyethylene. For example the mask may be formed as a triple layer SMS material which comprises a spunbond (S) polypropylene layer, a meltblown (M) polypropylene layer and another spunbond (S) polypropylene layer which can be ultrasonically welded together and cut to a desired mask shape. Ear loops, such as elasticated cords, to allow placement of the completed mask over the mouth and nose are also attached to each side of the mask by the production line machinery. The production line machinery may also fit a nose wire, valve or filter to the mask section.

[0005] The elastic cord used for ear loops may be manufactured on an industrial knitting machine that knits together filaments (also referred to as threads or yarn) to form a continuous elastic cord of long length with elasticity (or extensibility) in a desired range. The elasticity of the knitted cord can be controlled through choice of filament materials (e.g. combination of elastic and inelastic threads) in combination with the knitting pattern (e.g. type and frequency of different stitches). The individual filaments may be elastic threads, inelastic threads, or composite yams such as those comprising an elastic/extensible material such as rubber, synthetic rubber, elastane which is covered with an inextensible thread including natural fibres such as cotton, bamboo, hemp and wool fibres or from synthetic fibres such as polyester, nylon and rayon to provide some controlled elasticity/extensibility. For PPE mask applications synthetic or water repellent threads are typically used. After knitting the elastic cord is placed on a roll or in a box in loose (i.e. un-stretched) form and transported to the mask manufacture site where it is dispensed to the production line machinery.

[0006] During manufacture of a PPE mask a section of elastic cord is dispensed and then attached or welded to a mask. Accordingly the cord dispensing operation is an on-demand start- stop type operation (i.e. periodically repeated for each mask). However due to the composition and elasticity of the cord, direct dispensing of elastic cord from a roll, box or bag, to the production line machinery is problematic. In particular the on-demand nature, combined with the elasticity of the cord can lead to variations in tension (or elasticity) of the attached cord). Further knitted elastic cord is prone to snagging on itself particularly if provided in a box or bag form. Such snags are undesirable as they intermpt production whilst the cord is freed.

[0007] Thus to ensure rapid and uninterrupted manufacture of PPE face masks it is desirable to dispense the elastic cord for ear loops in a controlled manner. This places a number of constraints on the dispensing apparatus. First the dispensing apparatus must be configured to be in a permanent “ready to move immediately” state to ensure on-demand supply of cord. The production line may operate at a range of speeds, and thus the speed of the dispensing apparatus should be able to operate consistently over the required speed range (e.g. from zero to some maximum speed). Further it is desirable that the dispensing apparatus be able to automatically detect the speed, or otherwise be configured to be self-adjustable to operate at the desired speed without the need for an operator to set or adjust the speed. A further constraint is that as soon as cord is requested the cord should be fed at the required speed whilst maintaining tension of the cord in a desired range.

[0008] There is thus a need to provide an improved dispensing apparatus or at least a useful alternative to existing dispensing apparatus. SUMMARY

[0009] According to a first aspect, there is provided a dispensing apparatus for elastic cord, the apparatus comprising: a roller which in use feeds cord from a cord source; a plurality of cord guides; a primary cord feeder comprising a pair of pincher wheels comprising a drive wheel and an idle wheel, a first bobbin, a first bobbin mounting arrangement which is configured to constrain movement of the first bobbin along a first linear path, and a first bobbin position sensor configured to detect a position of the first bobbin in the first linear path; a secondary cord feeder comprising a second bobbin and a second bobbin mounting arrangement which is configured to constrain movement of the second bobbin along a second linear path; and a drive motor configured to drive rotation of the drive wheel; a roller motor configured to drive rotation of the roller; a control circuit configured to receive the output of the first bobbin position sensor, and turn the drive motor on and off, and the roller motor on and off, wherein, in use, the plurality of cord guides guide the cord from the cord source along a path towards and around the second bobbin, and then between the drive wheel and idle wheel of the pincher wheels, then towards and around the first bobbin and then towards a production line machinery wherein when the production line machinery is stopped, the first bobbin rests in a first idle position and the second bobbin rests in a second idle position and when the dispensing apparatus draws cord from the dispensing apparatus, the drawn cord causes the first bobbin to move along the first linear path and when the control circuit detects that the cord is being drawn by the production line machinery the control circuit turns the drive motor and the roller motor on, and when the control circuit detects that cord is no longer being drawn by the production line machinery, the control circuit turns the drive motor and the roller motor off.

[0010] In one form, the secondary cord feeder further comprises a second bobbin position sensor configured to detect a position of the second bobbin in the second path and the control circuit is configured to receive the output of the second bobbin position sensor, wherein the output of the first bobbin position sensor is used to control the drive motor, and the output of the second bobbin position sensor is used to control the roller motor. [0011] In a further form, the first bobbin mounting arrangement is vertically orientated to constrain movement of the first bobbin along a first vertical path and the second bobbin mounting arrangement is vertically orientated to constrain movement of the second bobbin along a second vertical path, and the first idle position is a lowermost position of the bobbin in the first vertical path and the second idle position is a lowermost position of the bobbin in the second vertical path.

[0012] In a further form, the first bobbin is a hanging bobbin in which the bobbin is supported by the cord passing under a bobbin shaft, and the bobbin mounting arrangement is configured to allow the bobbin to move freely up and down the vertical linear path.

[0013] In a further form, the first bobbin comprises a shaft passing through an inner flange, a middle flange and an outer flange, wherein a distance between the inner surfaces of the inner flange and middle flange is denoted by D, and a length of a channel formed from the shaft to the outer edge of the inner flange is F, and the first bobbin mounting arrangement comprises a pair of vertical rods and held in a spaced apart relationship by an upper mount and a lower mount, wherein the vertical rods each have a diameter d which is less than distance D and are spaced apart a distance .s which is greater than or equal to the shaft diameter S so the shaft can freely pass between the pair of vertical rods, and the length F is greater than or equal to the mid-point of the rods such that F ≥ d/2+(s-S)/2), and the middle flange and outer flange form a cord channel that constrains the cord such that the cord can loop around the shaft and support the bobbin.

[0014] In a further form, the first bobbin position sensor generates a binary output indicating whether the first bobbin is in the first idle position and the second bobbin position sensor generates a binary output indicating whether the second bobbin is in the second idle position.

[0015] In one form, the cord source is a pre-wound tube of elastic cord, and the dispensing apparatus further comprises a cord support arrangement which supports the pre-wound tube such that an outer surface of the pre-wound tube rests against the roller to dispense cord.

[0016] In one form, the dispensing apparatus further comprises a frame which supports a mounting panel and the mounting panel supports the plurality of cord guides, the primary cord feeder and the secondary cord feeder. [0017] According to a second aspect, there is provided a double cord dispensing apparatus comprising two dispensing apparatus each of the first aspect, wherein a single control circuit is used to control both of the dispensing apparatus.

[0018] According to a third aspect, there is provided a method for dispensing elastic cord, the method comprising: detecting, by a control circuit, movement of a first bobbin constrained to move along a first linear path away from an initial position due to a production line machinery drawing elastic cord from a dispensing apparatus wherein the drawn elastic cord passes around the first bobbin; turning on a drive motor to drive a drive wheel of a pair of pinch er wheels comprising the drive wheel and an idle wheel to dispense elastic cord towards and around the first bobbin; turning on a roller motor to drive a roller to draw elastic cord from a cord source, wherein the drawn elastic cord is guided towards and around a second bobbin constrained to move along a second linear path, and the elastic cord is guided into the pair of pincher wheels from the second bobbin; detecting, by the control circuit, return of the first bobbin to the initial position in response to the production line machinery ceasing to draw elastic cord from the dispensing apparatus; turning off the drive motor by the control circuit; and turning off the roller motor by the control circuit.

[0019] In one form, the method further comprises detecting, by a second bobbin position sensor, a position of the second bobbin in the second linear path, and controlling, by the control circuit, the roller motor based on an output of the second bobbin position sensor.

[0020] In a further form, the first linear path is a first vertical path and the second linear path is a second vertical path and the first idle position is a lowermost position of the bobbin in the first vertical path and the second idle position is a lowermost position of the bobbin in the second vertical path.

[0021] In a further form, the first bobbin position sensor generates a binary output indicating whether the first bobbin is in a first idle position and the second bobbin position sensor generates a binary output indicating whether the second bobbin is in a second idle position. BRIEF DESCRIPTION OF DRAWINGS

[0022] Embodiments of the present disclosure will be discussed with reference to the accompanying drawings wherein:

[0023] Figure 1 is a front view of a cord feeder mechanism of a cord dispensing apparatus according to an embodiment;

[0024] Figure 2A is a side sectional view of a cord dispensing apparatus according to an embodiment;

[0025] Figure 2B is a top view of a cord dispensing apparatus according to an embodiment;

[0026] Figure 2C is a sectional view of a bobbin according to an embodiment;

[0027] Figure 3A is a schematic drawing of the cord feeder mechanism of Figure 1 in an idle state according to an embodiment;

[0028] Figure 3B is a schematic drawing of the cord feeder mechanism of Figure 1 in an initial draw state according to an embodiment;

[0029] Figure 3C is a schematic drawing of the cord feeder mechanism of Figure 1 in a feeding state according to an embodiment;

[0030] Figure 3D is a schematic drawing of the cord feeder mechanism of Figure 1 in a first paused state according to an embodiment;

[0031] Figure 3E is a schematic drawing of the cord feeder mechanism of Figure 1 in an extended paused state according to an embodiment;

[0032] Figure 4A is an isometric view of a cord dispensing apparatus according to an embodiment;

[0033] Figure 4B is a front view of a cord dispensing apparatus according to an embodiment;

[0034] Figure 4C is a first side view of a cord dispensing apparatus according to an embodiment; [0035] Figure 4D is a second side view of a cord dispensing apparatus according to an embodiment;

[0036] Figure 4E is a top view of a cord dispensing apparatus according to an embodiment;

[0037] Figure 4F is an isometric view of a cord dispensing apparatus including a lid and front panels according to an embodiment;

[0038] Figure 5 A is an isometric view of a dual cord dispensing apparatus according to an embodiment;

[0039] Figure 5B is a front view of a dual cord dispensing apparatus according to an embodiment;

[0040] Figure 5C is a first side view of a dual cord dispensing apparatus according to an embodiment;

[0041] Figure 5D is a second side view of a dual cord dispensing apparatus according to an embodiment;

[0042] Figure 5E is a top view of a dual cord dispensing apparatus according to an embodiment; and

[0043] Figure 5F is an isometric view of a dual cord dispensing apparatus including a lid and front panels according to an embodiment.

[0044] In the following description, like reference characters designate like or corresponding parts throughout the figures.

DESCRIPTION OF EMBODIMENTS

[0045] Referring now to Figure 1, there is shown a front view of a cord feeder mechanism 10 of a cord 20 dispensing apparatus 1 according to an embodiment. Figures 2A and 2B are side sectional and top views of a dispensing apparatus 1 according to an embodiment. Embodiments of the dispensing apparatus are configured to have a standby condition in which the components are ready to move immediately to dispense elastic cord to a production line machinery - that is on demand as required by the production line machinery. Embodiments of the dispensing apparatus are further configured to dispense elastic cord over a range of different speeds to match the requested speed of the production line machinery. Thus the dispensing speed ranges from 0 m/min to a maximum speed. Further the speed of the dispensing apparatus is self- adjustable without requiring attendance of any operator (i.e. the apparatus dynamically or automatically responds to the speed requested by the production line machinery). In some embodiments the dispensing apparatus starts feeding the elastic cord whenever the manufacturing machine pulls the elastic cord according to the required speed whilst maintaining the tension of the cord at a minimal permitted (or desired) range.

[0046] The cord feeder mechanism 10 comprises a primary cord feeder (pinch er) system 30 and a secondary cord feeder (unwinder) system 31. A cord tension sensing system that is based on detecting the position of at least a first hanging bobbin is used. The primary cord feeder system 30 comprises a pair of pincher wheels comprising a drive wheel 32 and idle wheel 34 and a bobbin 52 whose motion is restricted to a first linear path by a first bobbin support arrangement 40 and a bobbin position sensor 54. The first bobbin position sensor 54 is configured to detect a position of the first bobbin in the first linear path. The secondary cord feeder system 31 comprises a similar second bobbin 52' whose motion is restricted to a second linear path by second bobbin support arrangement 40' and a second bobbin position sensor 54'. The second bobbin position sensor 54' is configured to detect a position of the second bobbin in the second linear path. In the embodiments shown in Figure 1 the first linear path and the second linear path are both vertical paths and the first bobbin support arrangement and second bobbin support arrangement are both vertically orientated.

[0047] The cord is guided through the cord feeder mechanism 10 by four cord guides comprising a first guide 13 which receives cord from a cord source and guides the cord into the secondary cord feeder system 31 towards the second bobbin 52', second and third guides which guide the cord out of the secondary cord feeder system 31 and towards the primary cord feeder system 30, and a fourth guide 16 which guides the cord out of the primary cord feeder system 30 towards the production line machinery. With reference to Figure 1 the cord feeder mechanism receives cord 20 from a source and the cord 20 can be divided into a first segment 21 from the source entry point to the first guide 13, a second segment 22 entering the secondary cord feeder system 30 towards second bobbin 52', a third segment 23 exiting the second bobbin 52' and secondary cord feeder system towards the second guide 14 located above the pincher wheels, a fourth segment 24 between second guide 14 and third guide 15 to position the cord above the pincher wheels, a fifth segment 25 exiting the third guide 15 towards driver wheel 32 and idle wheel 34 (where the cord is pinched between the wheels), a sixth segment 26 from the pincher wheels to the first bobbin 52, and a seventh segment 27 exiting the first bobbin 52 and primary cord feeder system 31 towards the fourth guide 16, and an eighth segment 28 which exits the fourth guide towards the production line machinery. It is noted that the cord is continuous and extends beyond the entry and exit points in Figure 1.

[0048] In this embodiment the cord guides are manufactured from tubular steel rods bent into an open spiral configuration. However it will be understood that other guide arrangements such as idle wheels, loops, and shaped guides manufactured from low friction materials may be used. The various components of the cord feeder mechanism 10 are mounted to a mounting panel 12. The mounting panel 12 may be mounted in a frame 80 comprising a first side 81, a front side 82, a second side 83 and a rear side 84. The sides of the frame may be comprised of tubular members such as rectangular steel members, and panels arranged to support and protect the components. The frame 80 may also support the cord source.

[0049] In this embodiment the cord source is a pre-wound tube 60 of elastic cord which has been wound onto a support tube 61 from which it is unwound and dispensed by the dispensing apparatus. The support tube 61 is mounted in a U shaped cord support arrangement comprising side arms 62 and rear plate 63 (e.g. a clevis type arrangement). The U shaped cord support arrangement has two rear projections 64 which are pivotally mounted to a tubular cross beam in the rear side 84 of the frame 80. Prior to use, a pre-wound tube 60 of elastic cord can be mounted in the U shaped cord support by manually pivoting the arms 62 rearward to loading position 66. Once a pre-wound tube 60 is loaded the end of the cord can then be fed over the roller 68, through circular guide 85 and lateral guide 86 and then through the feeding mechanism 10 of the dispensing apparatus 1 and then outwards to the production machinery. The arms 62 are then pivoted forward until the outer surface of the pre-wound tube 60 rests against a roller 68 mounted in an upper portion of the frame in a transverse orientation from the first side 81 to the second side 83. The roller is driven by an unwinder motor 72 via belt 69 to drive unwinding of the cord 20 from the pre-wound tube 60 via frictional contact with the outer surface of the pre wound tube 60. As cord is progressively wound off the pre-wound tube 60, and the diameter of the pre-wound tube 60 reduces and the arms 62 pivot downward under gravity to maintain contact between the outer surface of the pre-wound tube 60 and the roller 68. [0050] The location of the roller 68 is chosen such that when all the cord has been dispensed the empty tube 61' rests against the roller 68. This is indicated in Figure 2A by pivot position 67 (dotted line corresponding to centre line of arms 62) along with empty support tube 61 ' (also shown in dotted lines). When all the cord has been dispensed (or a desired amount of the cord) the arms 62 can then be pivoted up to the loading position, and the empty/dispensed tube 61 removed, and another pre-wound tube of elastic cord 60 is loaded. Note that if required reloading can be performed prior to full dispensing of cord, for example just prior to full dispensing when only a few metres are left on the tube 61. An arm position sensor may be used to generate an alarm when the arm reaches a threshold position indicating the pre-wound cord is almost unwound (or fully unwound) and thus needs to be replaced (or will shortly need to be replaced). In one embodiment an angle sensor measure is attached to the arm or U shaped cord support arrangement to detect the angle of the arm with respect to a horizontal plane. The threshold value may correspond to the pivot position 67 or a position just prior when the pre-wound tube is almost empty. The output of the sensor may be sent to the control circuit for processing and generation of an alarm, or the sensor may generate a binary output indicating whether the angle is above or below a threshold angle.

[0051] During normal use the direction of rotation of the roller 68 is configured to unwind cord of the support tube 61 (e.g. rotates counter clockwise in Figure 2A). If the cord is supplied in a loose form, for example in a box or a bag, then the direction of rotation of the roller apparatus can be reversed (e.g. clockwise in Figure 2A) and used to wind loose cord onto the roller. In other embodiments, the apparatus could be adapted for dispensing cord which is not supplied on a pre-wound tube, such as from a box or a bag. This may be stored in a coiled or pre-wound configuration in the box or bag, or in loose form in the box or bag. In these embodiments, the U shaped apparatus could be replaced with a shelf to store a box or support or hang a bag. The single roller 68 could be replaced with a pair of rollers comprising a driver roller 68 and an idle roller 61 ' which receives cord from the box or bag. The pair of rollers could then dispense and direct the cord towards circular guide 85 and/or lateral guide 86, or be placed between circular guide 85 and lateral guide 86.

[0052] The circular guide 85 may comprise a steel rod mounted to the front side 82 of the frame with a circular loop located at the distal end of the rod. The lateral guide 86 may comprise a steel rod extending from the first side 81 to the second side 83 and located vertically above the mounting panel 12 of the cord feeder mechanism 10. The use of the central guide ensures the cord is delivered at a constant fixed angle to the first guide 13 on the front face of the mounting panel 12 of the cord feeder mechanism 10, whilst the angle from the roller 68 to the circular guide 85 varies across the face of the pre-wound tube of elastic cord 60. In some embodiments the circular guide 85 and/or lateral guide 86 could be omitted and other arrangements could be used, such as shaped guides made of low friction materials (e.g. plastics) or a cable run could be formed using conduit tube to guide the cable.

[0053] The operation of the primary and secondary cord feeders 30, 31 and the cord tension sensing system will now be discussed with reference to Figures 1 to 3E. The primary cord feeder (or pincher) system 30 comprises a pair of pincher wheels (cord feeder wheels) comprising a drive pincher wheel 32 and an idle wheel 34 and an electro mechanic cord tension sensing system which is triggered when the cord is under its minimal tension and stretch. When the tension sensing system of pincher system 30 is triggered, the pincher wheels start feeding the elastic cord to the production line machinery (by driving drive pincher wheel 32). The secondary (or unwinder) cord feeder system 31 uses a similar electro mechanic cord tension sensing system which senses the tension of the cord behind the pincher which triggers the secondary cord feeder to start unwinding the tube 60.

[0054] The pincher wheels (or cord feeder wheels) comprise a drive wheel 32 which is driven by a drive motor 74 via belt 75 and an idle wheel 34 which is mounted to the panel 12 via mounting arrangement 39 (the drive motor 74 could also be called the pincher motor as it drives the drive wheel of the pincher wheels). The belt 75 drives an axle of the driver wheel through the panel 12 and is supported by a first bearing mounted to (or in) the panel 12. The idle wheel is mounted so that it is free to rotate and is biased towards the pincher wheel 32 by a tension spring 37 located behind the mounting panel 12. In one embodiment the mounting arrangement comprises a pivot arm where the idle wheel is mounted on the distal end and the distal end is further attached to the tension spring 37 which is anchored proximal to the drive wheel. The contact normal force between the drive wheel 32 and idle wheel 34 is thus controlled by the tension spring 37 which functions to hold the wheels 32, 34 in contact with each other and to keep the elastic cord pinched at a controlled friction force (and thus a desired cord tension).

[0055] The cord tension sensing system comprises a control circuit which is configured to receive the output of the first bobbin position sensor and the second bobbin position sensor, and turn the drive motor on and off, and the roller motor on and off. When the dispensing apparatus draws cord from the dispensing apparatus, the drawn cord causes the first bobbin to move along the first linear path and the control circuit is configured to detect that the cord is being drawn by the production line machinery via movement of the first bobbin from an initial idle position. The control circuit turns the drive motor and the roller motor on, and when the control circuit detects that cord is no longer being drawn by the production line machinery, the control circuit turns the drive motor and the roller motor off. This may be determined by the control circuit by detecting that the first bobbin has returned to the initial idle position.

[0056] The primary cord feeder system 30 comprises a bobbin 52 around which the cord passes, a bobbin mounting arrangement 40 and a bobbin position sensor 54. An identical bobbin 52', bobbin mounting arrangement 40' and a bobbin position sensor 54' is used for the secondary cord feeder (unwinder) system 31. Similar part numbers are shown in the Figures and denoted with a

Accordingly given the similarities the bobbin 52 around which the cord passes, a bobbin mounting arrangement 40 and a bobbin position sensor 54 will now be described and it is to be understood a similar arrangement is used for the secondary cord feeder (unwinder) system 31.

[0057] A cross section of the bobbin 52 is shown in Figure 2C. The bobbin comprises a shaft 58 passing through three flanges which we will refer to as inner flange 55, middle flange 56 and outer flange 57 (defined with respect to panel 12). The distance between the inner surfaces of the inner flange and middle flange is denoted by D, and the length of the channel formed from the shaft 58 to the outer edge of the inner flange 55 (and middle flange 56) is F.

[0058] The bobbin 52 is restricted to freely move back and forth along a linear path by a bobbin mounting arrangement 40. In this embodiment the linear path is a vertically orientated linear path so the bobbin is restricted to vertical movements (i.e. up and down) over the mounting panel 12. The bobbin mounting arrangement (which we also refer to by the shorter name: bobbin support) comprises a pair of vertical rods 45 and 48 held in a spaced apart relationship by an upper mount 47 and a lower mount 48. The vertical rods 45, 47 have a diameter d which is less than the distance between the inner surfaces of the inner flange and middle flange D (i.e. d<D) and are spaced apart a distance s (as measured from the inner surfaces of both rods) which is greater than or equal to the shaft diameter S so the shaft can freely pass between the rods 45 and 47. Strictly in the equal case the shaft 58 and rods 47, 45 are required to be frictionless (or nearly so) to allow free movement of the bobbin and thus it is preferable to maintain at least some small gap (i.e. s > S). Additionally the length of the flanges F from shaft to outer edge should extend to or past the mid-point of the rods (i.e. F ≥ d/2+(s-S)/2), and preferably the distance F is at least the diameter of the rods (i.e. F > d). The vertical rods may be solid or hollow with a circular or square cross section, although other geometries could be used provided they constrain the bobbin within the inner and middle flanges 55, 56 so as limit movement along a vertical linear path.

[0059] The channel formed between the middle flange 56 and outer flange 57 (the cord channel) constrains the cord such that the cord can loop around the shaft 58 and support the bobbin (ie to create a hanging bobbin). The distance between the inner surfaces of the middle flange 56 is selected to exceed the diameter of the cord 20, and similarly the length of the channel formed from the shaft 58 to the outer edge of the outer flange 57 is larger than the diameter of the cord 20. As illustrated in Figures 1 and 2C, the sixth segment 26 passes around the shaft and exits the bobbin as seventh segment 27.

[0060] In this embodiment a bobbin position sensor 54 is located behind the bobbin 52 and the output is used by the control circuit 71 to control the drive motor 74 (i.e. turn on or off) used to drive the drive wheel of the pincher wheels. The first bobbin position sensor is configured to detect a position of the first bobbin in the first linear path. In one embodiment the bobbin position sensor 54 is configured to detect if the bobbin 52 is in an idle (or initial) position in the (vertical) linear path, corresponding to the first bobbin resting (in an idle state) on the lower mount 48. When the bobbin position sensor 54 detects (vertical) motion of the bobbin 52 away from the idle position (in response to cord being drawn by the production line machinery) the drive motor 74 is turned on to drive the drive wheel 32 of the pincher. When the bobbin returns to the idle position (in response to the production line machinery pausing or stopping) the return is detected by the bobbin position sensor 54 and the drive motor 74 is stopped. Similarly in the secondary cord feeder system, a second bobbin position sensor 54' is located behind the second bobbin 52' and is used to control the cord feeder motor 72. Similarly when (vertical) motion of the second bobbin 52' away from the idle position is detected by the second bobbin position sensor 54' this turns on (triggers) the roller motor 72 to drive the roller 68 to dispense cord from the cord source (pre-wound tube 60). The bobbin position sensor may generate an output signal which is used by a control circuit 71 which controls (i.e. turns on and off) the drive motor 74. In one embodiment the control circuit 71 uses a programmable logic controller (PLC) which processes the output of the first and second bobbin position sensors 54, 54' output signals and controls the start and stop of the pincher and roller motors 72, 74 in response. Other control circuit arrangements may be used including discrete components, microcontrollers, microprocessors, etc. [0061] The operation of the primary cord feeder 30 (and control circuit 71) will now be described with reference to Figures 3 A to 3E. It is first noted that the motors rotate at a constant speed however there is acceleration and deceleration for all motors. This means that all motors need time for start from zero to reach the nominal speed and similar time for deceleration to stop.

[0062] However as noted above, the dispensing apparatus is required to cover a range of production rates; from zero rate (when the production line is paused or not working) to the maximum production rate (i.e. maximum speed) which will be predefined prior to operation (e.g. in a design phase). Thus in order to enable motors operating at a constant speed to cover a range of production rates, this apparatus uses a hanging bobbin 52. The bobbin 52 is supported by the cord passing under a bobbin shaft 58, and the bobbin mounting arrangement 40 is configured (or arranged) to allow the bobbin 52 to move freely up and down the vertical linear path. i.e. upward movement of the cord drives movement of the bobbin upward along the path, and as the cord moves down (which may be due to a gravitational force due to the bobbin), the bobbin moves down. The bobbin 52 plus the height of its position during dispensing, has two functions: namely keeping a very low tension on the elastic cord being dispensed and accumulating enough cord when the production machinery works at high speed (rate). More details of the mechanisms are explained in figures 3 A to 3E which show how the pincher wheel driven by a motor with constant rotation can cover a variable production rate.

[0063] As noted the production line machinery pauses to perform other operations thus the feed rate to the machinery is not constant but intermittent (i.e. on-demand). The process time for fed material is nearly fixed but the feed speed changes and thus the average production rate of the machinery basically depends on the feed rate not the processing time. In designing the dispensing apparatus, the design took advantage of the processing time of the production line machinery to accumulate the cord with running a low speed motor which requires low power.

[0064] Figure 3 A is a schematic drawing of the cord feeder mechanism of Figure 1 in an idle state according to an embodiment. This represents stage 1 where the pincher wheels 32, 34 (tension sensing mechanism) are stationary, and the bobbin 52 is in its lowest position. We denote the tension of the cord in the stationary (static) position as T1. It can be seen in Figure 1 that the tension in the sixth 26, seventh 27 and eighth 28 cord segments are identical and is each T1. We define Wb as the weight of the bobbin, L as the travelling distance of the bobbin (the vertical length from lower mount 48 to upper mount 47 of the bobbin mounting arrangement). We further define the angle between the elastic cord and horizontal line (extending from fourth guide 16) as α, and Fx as the tension force on the idle wheel 34 due to bias spring 37 (Fx = k.x where k is the spring constant). We further assume that there is no or negligible friction on the contact surface between the elastic cord and the wheels, rollers, or guides, and there is no or negligible friction in the bearings of the rollers or wheels. Finally we note that if 70° < α < 90° then T1 ≈ Wb/2.

[0065] Figure 3B is a schematic drawing of the cord feeder mechanism of Figure 1 in an initial draw state according to an embodiment. This represents stage 2 where the production line machinery begins to pull out the elastic cord 20 with linear speed of Vm. The tension in the cord when the production line machinery pulls out the cord is designated Tm and the velocity of the cord when it is pulled out by the production line machinery is Vm. This causes the bobbin to move upwards from its rest position on the lower mount 48 (of the bobbin support) at velocity Vb. We note that when Tm > Wb/2 then Vb < Vm/2.

[0066] Figure 3C is a schematic drawing of the cord feeder mechanism of Figure 1 in a feeding state according to an embodiment. This represents stage 3 where the bobbin position sensor 54 detects (upward) movement of the bobbin and triggers the drive motor 74 to turn on (and stay on) and drive the drive wheel 32 at a constant speed to feed the cord from pincher mechanism. We denote Vf as the linear speed of the cord fed by the pincher wheels 32, 34. As Vm > Vf the bobbin 52 moves upwards. In this dynamic condition, cord tensions in the fifth segment 25 (RHS of bobbin 52) and sixth segment 26 (LHS of bobbin 52) are not the same and they vary as the bobbin keeps moving. We denote Tf as the tension of the cord in fifth segment 25 (RHS of bobbin in figure 3C). We further note that Tm+Tf > Wb/2 and thus the bobbin stays above the lower mount 48 of the bobbin support.

[0067] Figure 3D is a schematic drawing of the cord feeder mechanism of Figure 1 in a first paused state according to an embodiment. This represents stage 4 where the production line machinery first pauses for processing time (or for complete stop) and thus no more cord is required. Thus the production line machinery velocity drops to zero (Vm=0) and Tension drops to zero (Tm = 0). At this point in time the drive motor 74 is still running because the bobbin 52 is still up (i.e. away from idle position) and thus the bobbin position sensor 54 is still triggered (and thus Vf > 0). As the production line machinery velocity is zero (Vm =0), the tension T in the sixth segment 26 T<< W b/2 and thus the bobbin will start to move downward under gravity as we have T+Tf < Wb/2. In this case the length of cord fed to the production line is approximately 2L. [0068] Figure 3E is a schematic drawing of the cord feeder mechanism of Figure 1 in an extended paused state according to an embodiment. This represents stage 5 where the production line machinery has remained paused for an extended time (e.g. processing time), and thus as in the previous stage 4 case Vm=0 and Tm=0. However as the bobbin 52 is still elevated and has not yet made it back to the lower mount 48 of the bobbin support (the idle position), the bobbin position sensor 54 is still triggered and thus the drive motor 74 is still running. Accordingly Vf > 0, T << Wb/2 and T+Tf < Wb/2.

[0069] As the production line machinery remains paused, the bobbin 52 will eventually drop back down to the lower mount 48 of the bobbin support, the bobbin position sensor 54 will detect the return of the bobbin 52 to the initial/idle position and turn off the drive motor 74. The pincher mechanism is thus once again stationary and we return to the state shown in Figure 3 A.

[0070] As noted above the secondary (or unwinder) cord feeder system 31 uses a similar electro mechanic cord tension sensing system as described above. In this system the second bobbin position sensor 54' detects movement of the second bobbin 52' due to a change in tension in the third cord segment (i.e. behind the pincher wheels 32, 34) and this triggers the secondary cord feeder to turn on the unwinder motor 72 to drive unwinding of the cord 20 from the pre-wound tube 60 (or similar source) to supply the cord feeder mechanism.

[0071] Thus to summarise, turn on/operation of the production line machinery draws cord from the cord feeder mechanism and thus induces vertical movement of the first bobbin 52. This (vertical) movement is detected by the first bobbin position sensor 54 which turns on drive motor 74. This is turn draws cord from the secondary cord feeder system and induces vertical movement of the second bobbin 52'. This (vertical) movement is detected by the second bobbin position sensor 54' which turns on roller motor 74 to supply cord from the cord source. Whilst the production line machinery is operating, the tension in cord keeps the bobbins raised above their idle positions. Then when the production line machinery stops the drop in tension in the seventh segment 27 allows the first bobbin 52 to return to the initial position (i.e. lower mount 48) which is detected by the bobbin position sensor 54 which turns off the drive motor 74. This in turn leads to a reduction in the tension in the third segment, thus allowing the second bobbin 52' to return to the initial position (i.e. lower mount 48') which is detected by the second bobbin position sensor 54' which turns off the roller motor 72. [0072] The first and second bobbin position sensors 54, 54' are configured to detect whether the respective bobbins 52, 52' are in the idle position or not. This may be detected using a sensor mounted on the panel 12 behind the bobbin in the idle position (i.e. proximal to the lower mounts 48, 48'). A range of sensor types may be used. For example an optical sensor such as photodiode may be used to detect a reflected signal from the bobbin or a magnetic or electromagnetic sensor may detect the proximity of a metal bobbin or metal component attached to the bobbin based on field strength or induced current. Mechanical trip or deflection switches could also be used which physically detect movement of the bobbin. A computer vision system could also be used which views the bobbin position. This may be configured to identify the bobbin position in an image and determine if it is in the idle position or not. The output state of the sensor is provided to the control circuit.

[0073] In the above embodiments the drive motor 74 and roller motor 72 are independently driven based on first and second bobbin position sensors 54 and 54' respectively. However in other embodiments a single bobbin position sensor 54 may be used to drive both the drive motor 74 and roller motor 72. In this embodiment the drive motor 74 and roller motor 72 may be simultaneously started (and stopped) based on detection of movement of the bobbin 54 by the control circuit 71. Alternatively the control circuit may start (and end) the motors in sequence by applying a fixed (or predetermined) delay. For example the control circuit 71 may start (or stop) the drive motor 74 and after a suitable delay (e.g. 100ms, 500ms, Is) start (or stop) the roller motor 72.

[0074] With reference to Figures 3 A to 3E, it is further noted that at higher production rates, the bobbin will move higher due to the higher acceleration caused by rapid induced tension at higher production rate. Thus the maximum speed that the dispensing apparatus can dispense cord will be determined based on the length of the vertical rods 45, 47 in conjunction with the weight of the bobbin 54. Conversely the maximum design speed of the dispensing apparatus can thus be determined based on length of the vertical rods 45, 47 and the weight of the bobbin 54.

[0075] When dispensing the cord to the production line it is desirable that the tension of the cord should be kept as low as possible (e.g. at some minimum permitted range). As the elastic cord is very soft and stretchy, by a few grams of load it can easily be stretched to 10% of initial length. The rapid detection and feeding of cord by the dispensing apparatus ensures that the production line machinery can be fed with the cord having a small amount of pre-tension within a desired or permitted range (and this pre-tension can be released in production machinery). The weight of bobbin is selected to comply with two opposing requirements. A heavier bobbin (with higher mass) compared to a lighter bobbin will jump up slower and drop faster (due to the higher gravitational force associated with the higher mass) which is in the favour of unwinder reliability and a quick response. However a lighter bobbin (with a lower mass) induces lower tension on the cord and the unwinder can feed nearly a tension free cord to the production line. Thus the weight of the bobbin is limited to a small range to satisfy both requirements.

[0076] An embodiment of a single cord dispensing apparatus is further illustrated in Figures 4A, 4B, 4C, 4D and 4E which, respectively show isometric, first side 81, front side 82, second side 83 and top views. Figure 4F shows an isometric view of the cord dispensing apparatus including a lid and front panels according to an embodiment. In this embodiment the frame 80 further comprises panels to form a cabinet and is mounted on wheels. The cord feeder mechanism 10 is located in the middle of the front side (face) 82 above which is housed the pre-wound tube 60 of elastic cord. Embodiments of the apparatus shown in Figures 4A to 4E each feed a single cord, and thus in manufacturing a mask which requires two ear loops, two units may be placed on either side of the production line to feed cord to each side of a mask (to form a respective ear loop).

[0077] In another alternative illustrated in Figures 5 A to 5E, a double cord feeder apparatus 100 is illustrated which can be used to feed two cords to a production line machinery from a single side. Figures 5 A, 5B, 5C, 5D and 5E respectively show isometric, first side 81, front side 82, second side 83 and top views. Figure 5F shows an isometric view of the cord dispensing apparatus including a lid and front panels according to an embodiment. In this embodiment the frame 80 further comprises panels to form a cabinet and is mounted on wheels. Two separate cord feeder mechanisms 10, 10' are located side by side in the middle of the front side (face) 82 above which is housed two pre-wound tubes 60, 60' of elastic cord. In this embodiment a single control circuit 71 may be used to drive both drive motors 72, 72' and both roller motors 74, 74' (not shown). The control circuit may receive separate inputs from the bobbin position sensors in each cord feeder mechanism 10, 10' and separately drive the motors for the separate cord feeder mechanisms 10, 10' (i.e. so only a single PLC or similar controller is required). Alternatively bobbin position sensors may be used on a single cord feeder mechanism and the sensor output used to drive both drive motors 72, 72' and both roller motors 74, 74', or a single bobbin position sensor may be used to drive all four motors (drive motors 72, 72' and roller motors 74, 74' which may be simultaneous or delayed with respect to the drive motors 72, 72'). [0078] Other variations on the embodiments discussed above are possible. For example as outlined above the bobbin mounting arrangement limits the bobbin to move along a linear path. In the above embodiments the bobbin mounting arrangement is vertically mounted to limit movement along a vertical linear path. This is to maximise the gravitational force on the bobbin to maximise responsiveness of the system. However it will be realised that the bobbin mounting arrangement could be mounted in an inclined arrangement so the linear path is an inclined path. In the above embodiments the bobbin position sensor 54 detects a fixed initial position when the bobbin is resting on the lower mount. However as illustrated in Figures 3A to 3E, when the production line machinery turns on and pulls cord this causes the bobbin to move vertically. Thus in an alternative embodiment the initial position could be a minimum height above the lower mount 48 (i.e. vertically offset from the lower mount). This may assist in preventing a rapid turn on/off in the case of the bobbin bouncing off the lower mount. In this embodiment the output signal of the sensor corresponds to the off state whilst position of the bobbin is between the lower mount and the minimum height. In other embodiments bobbin position sensor could detect the position along the entire linear path and output the position to the control circuit. This output signal is then processed by the control circuit to determine when to turn on and off the motors. In the above embodiments the bobbin position sensor uses the same bobbin position to turn the motors on and off. However it will be understood that the bobbin sensor could be configured to use a first position for turning the motor on, and a second position for turning the motor off. In yet another embodiment the position sensor could be configured to operate in a differential mode which compares the present position with a previous position to detect whether the bobbin is moving or idle (i.e. at rest on the lower mount 48). In yet another embodiment the position sensor could be a movement sensor which detects movement of the bobbin and the position is inferred or estimated from the detected movements. In another embodiment the position sensor detects speed of the bobbin which is used to estimate position.

[0079] In a general form a dispensing apparatus for elastic cord can be provided comprising: a roller which in use feeds cord from a cord source; a plurality of cord guides; a primary cord feeder comprising a pair of pincher wheels comprising a drive wheel and an idle wheel, a first bobbin, a first bobbin mounting arrangement which is configured to constrain movement of the first bobbin along a first linear path, and a first bobbin position sensor configured to detect a position of the first bobbin in the first linear path; a secondary cord feeder comprising a second bobbin and a second bobbin mounting arrangement which is configured to constrain movement of the second bobbin along a second linear path; and a drive motor configured to drive rotation of the drive wheel; a roller motor configured to drive rotation of the roller; a control circuit configured to receive the output of the first bobbin position sensor, and turn the drive motor on and off, and the roller motor on and off, wherein, in use, the plurality of cord guides guide the cord from the cord source along a path towards and around the second bobbin, and then between the drive wheel and idle wheel of the pincher wheels, then towards and around the first bobbin and then towards a production line machinery wherein when the production line machinery is stopped, the first bobbin rests in a first idle position and the second bobbin rests in a second idle position and when the dispensing apparatus draws cord from the dispensing apparatus, the drawn cord causes the first bobbin to move along the first linear path and when the control circuit detects that cord is being drawn by the production line machinery the control circuit turns the drive motor and the roller motor on, and when control circuit detects that cord is no longer being drawn by the production line machinery, the control circuit turns the drive motor and the roller motor off.

[0080] Similarly a method for dispensing elastic cord has also been developed based on the dispensing apparatus as described herein. In one embodiment the method comprises: detecting, by a control circuit, movement of a first bobbin constrained to move along a first linear path away from an initial position due to a production line machinery drawing cord from a dispensing apparatus wherein the drawn cord passes around the first bobbin; turning on a drive motor to drive a drive wheel of a pair of pincher wheels comprising the drive wheel and an idle wheel to dispense cord towards and around the first bobbin; turning on a roller motor to drive a roller to draw cord from a cord source, wherein the drawn cord is guided towards and around a second bobbin constrained to move along a second linear path, and the cord is guided into the pair of pincher wheels from the second bobbin; detecting, by the control circuit, return of the first bobbin to the initial position in response to the production line machinery ceasing to draw cord from the dispensing apparatus; turning off the drive motor; and turning off the roller motor. [0081] The above apparatus and method can be further modified based on the embodiments described above and implemented using the components and apparatus described herein.

[0082] Embodiments of the dispensing apparatus are configured to have a standby condition in which the components are ready to move immediately to dispense elastic cord to a production line machinery - that is on demand as required by the production line machinery. Embodiments of the dispensing apparatus are further configured to dispense elastic cord over a range of different speeds to match the requested speed of the production line machinery - at least up to some maximum speed which may be determined based on the length of the rods 47 and 45 and bobbin weight. Over this range the speed of the dispensing apparatus is self-adjustable without requiring attendance of any operator with the apparatus dynamically (or automatically) responding to the speed requested by the production line machinery. This is enabled by a cord feeder mechanism 10 using a hanging bobbin arrangement in which the cord passes around the bobbin and the bobbin is restricted to move freely up and down along a vertical linear path by a bobbin mounting arrangement 40 as described herein. A bobbin position sensor 54 is used to detect movement of the bobbin from an initial or idle position resting on lower mount 48. The bobbin position sensor 42 detects the vertical movement of the bobbin in response to the production line machinery drawing cord triggering turning on of the drive motor to drive a drive wheel to feed cord to the production line machinery. A similar hanging bobbin and bobbin sensing mechanism may be used to turn on a roller motor to drive a roller to feed cord from a pre-wound tube 60 to the cord feeder mechanism. In some embodiments the dispensing apparatus starts feeding the elastic cord whenever the manufacturing machine pulls the elastic cord according to the required speed whilst maintaining the tension of the cord at a minimal permitted (or desired) range. Single and double feed systems may be constructed to allow feeding from either side or a single side of a production line machinery.

[0083] Those of skill in the art would understand that information and signals may be represented using any of a variety of technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0084] Those of skill in the art would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software or instructions, middleware, platforms, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0085] The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor (including a microprocessor), or in a combination of the two. For a hardware implementation, processing may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, or other electronic units designed to perform the functions described herein, or a combination thereof. Various middleware and computing platforms may be used. In some embodiments the processor module comprises one or more Central Processing Units (CPUs). A CPU may comprise an Input/Output Interface, an Arithmetic and Logic Unit (ALU) and a Control Unit and Program Counter element which is in communication with input and output devices through the Input/Output Interface. The Input/Output Interface may comprise a network interface and/or communications module for communicating with an equivalent communications module in another device using a predefined communications protocol (e.g. Bluetooth, Zigbee, IEEE 802.15, IEEE 802.11, TCP/IP, UDP, etc.). The computing apparatus may comprise a single CPU (core) or multiple CPU’s (multiple core), or multiple processors. Memory is operatively coupled to the processor(s) and may comprise RAM and ROM components, and may be provided within or external to the device or processor module. The memory may be used to store an operating system and additional software modules or instructions. The processor(s) may be configured to load and executed the software modules or instructions stored in the memory.

[0086] Software modules, also known as computer programs, computer codes, or instructions, may contain a number a number of source code or object code segments or instructions, and may reside in any computer readable medium such as a RAM memory, flash memory, ROM memory, EPROM memory, registers, hard disk, a removable disk, a CD-ROM, a DVD-ROM, a Blu-ray disc, or any other form of computer readable medium. In some aspects the computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). In addition, for other aspects computer-readable media may comprise transitory computer- readable media (e.g., a signal). Combinations of the above should also be included within the scope of computer- readable media. In another aspect, the computer readable medium may be integral to the processor. The processor and the computer readable medium may reside in an ASIC or related device. The software codes may be stored in a memory unit and the processor may be configured to execute them. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art.

[0087] Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by computing device. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.), such that a computing device can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

[0088] The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

[0089] As used herein, the term “determining” and “estimating” encompasses a wide variety of actions. For example, these may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining , receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) , resolving, selecting, choosing, establishing and the like. [0090] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the common general knowledge.

[0091] It will be understood that the terms “comprise” and “include” and any of their derivatives (e.g. comprises, comprising, includes, including) as used in this specification, and the claims that follow, is to be taken to be inclusive of features to which the term refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied.

[0092] In some cases, a single embodiment may, for succinctness and/or to assist in understanding the scope of the disclosure, combine multiple features. It is to be understood that in such a case, these multiple features may be provided separately (in separate embodiments), or in any other suitable combination. Alternatively, where separate features are described in separate embodiments, these separate features may be combined into a single embodiment unless otherwise stated or implied. This also applies to the claims which can be recombined in any combination. That is a claim may be amended to include a feature defined in any other claim. Further a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0093] It will be appreciated by those skilled in the art that the disclosure is not restricted in its use to the particular application or applications described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope as set forth and defined by the following claims.