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(11) | EP 3 168 352 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | UNIT AND METHOD FOR WASHING NEEDLE HOLDER PLATES FOR KNITTING MACHINES |
| (57) Described is a unit for washing needle holder plates for knitting machines equipped
with a tank with a longitudinal axis inside of which a shelf supports a needle holder
plate which comprises a plurality of grooves extending transversely to the axis of
the tank closed on one side and open on the working side; a plurality of needles,
each of which is positioned inside the respective groove, is free to move along the
groove itself coming out partly from the working part; the washing unit comprises
a washing head and a device for supporting the washing head, the latter comprising
a first guide extending parallel to the longitudinal axis of the tank and a second
guide extending in a direction perpendicular to the first; the device for supporting
the head can perform a first sliding with a first law of motion along the first guide
in both forward and return directions and the washing head is mounted slidably on
the second guide and perform a second sliding with a second law of motion along the
second guide in both directions; the washing head comprises a first nozzle able to
generate a first jet of washing liquid directed and oriented perpendicularly towards
the needle holder plate, a second nozzle able to generate a second washing jet directed
and oriented inclined towards the plate and a third nozzle able to generate a third
washing jet directed and oriented inclined specularly towards the first towards the
plate itself; by performing the first and second sliding in combination with the first
and second law of motion, the washing unit makes it possible to effectively washed
the needle holder plate move the needles inside the respective grooves under the action
of the third jet. [Figure 1]
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[0001] The invention relates to a unit and a method for washing needle holder plates for knitting machines.
[0002] More specifically, this invention relates to a unit and a method for washing needle holder plates, so-called "needlebeds", which form part of the current machines for the industrial production of knitwear fabrics and sheets.
[0003] These types of machines, for the industrial production of knitwear sheets, and in particular the needle holder plates, to which reference is explicitly made in this description, require regular maintenance mainly on account of the dirt which deposits on all the components in contact with or in the vicinity of the area where the thread is processed, releasing residue of different extent and size, such as, for example, the fluff of the fabrics and wool processed. These residues in turn mix with lubricants and other chemical products necessary for the correct operation of the needlebeds, in which solid sediments are consequently created, having dimensions also in the order of millimetres, which adhere with force on the surfaces and on the apertures of the needlebeds themselves.
[0004] The necessary cleaning planned in the regular maintenance of industrial knitting machines is currently performed manually by qualified personnel who dismantle the parts to be washed in relative sub-components in order to avoid damaging the more delicate ones and to clean the areas which are difficult to reach, including the grooves of the needlebeds along which run the needles which create the weave and the needles which are the most delicate components.
[0005] As is known, the needle holder heads of the current knitting machines of the movable carriage type generally consist of a supporting plate made of metallic material, usually of rectangular elongate shape, which has a series of transversal rectilinear grooves on the upper face.
[0006] The grooves, one parallel to the other, extend at right angles to the longitudinal axis of the plate for the entire relative width.
[0007] Inside each groove a respective needle of oblong and flattened shape is inserted in an axially slidable manner in such a way that it can move between a completely extracted position wherein the hook shaped end of the needle protrudes in a cantilever fashion from the side wall of the supporting plate by a maximum predetermined length and a completely retracted position wherein the entire needle is housed inside the body of the support plate.
[0008] Inside each transversal rectilinear groove, the above-mentioned needle holder head comprises a needle moving selector, which is also inserted in an axially slidable manner inside the rectilinear transversal groove behind the needle, and is hooked to the latter in such a way as to be able to move forwards and backwards between the two limit positions described above.
[0009] Usually, the above-mentioned selector element is equipped with a control tooth which projects in a cantilever fashion and at right angles from the upper face of the supporting plate.
[0010] Each tooth is designed to be selectively hooked by the cam movement device of the movable carriage of the knitting machine, in such a way as to be moved along a direction parallel to the transversal rectilinear groove, allowing the needle to be selectively moved inside the groove.
[0011] In the majority of cases, the needle holder head comprises, inside each rectilinear groove, also a "plate" which, acting in conjunction with the heal of the needle and/or the needle moving selector, is able to give differential commands to the needle, varying the relative position inside the rectilinear groove.
[0012] In order for the needle holder heads to operate normally they must be regularly subjected to washing since, as mentioned above, during normal operation of the knitting machine, the fluff tends to accumulate on the bottom of the individual transversal rectilinear grooves until they completely block the movement of the needle inside the groove.
[0013] Machines are currently known for the industrial production of knitwear which comprise a tank inside of which there is a structure for supporting the above-mentioned needle holder head positioned with its longitudinal axis parallel to the longitudinal axis of the tank.
[0014] According to a first embodiment of these machines, a runner is mounted in a movable fashion above the needle holder head in such a way that it can move with a to and fro motion along the same direction parallel to the axis of the tank, relative to the head.
[0015] The head cleaner runner is shaped in such a way as to touch the upper face of the needle holder head over its entire length.
[0016] The cleaning runner is provided with a plurality of nozzles each of which is connected to a hydraulic circuit from which it receives a flow of water and/or solvents under pressure and directs them against the upper surface of the needle holder head.
[0017] The head cleaner runner is provided, on its surface facing the surface of the needle holder head, with a mechanism for movement of the needles, consisting usually of a cam profile which, when advancing along the above-mentioned longitudinal direction, encounters the teeth of plates and allows the forwards and backwards movement of each needle inside the respective seat or groove.
[0018] This enables the liquid which is shot under pressure by the nozzles against the needle holder head to reach the bottom of the grooves and the needles in a more energetic and complete manner.
[0019] A second embodiment of these machines comprises a supporting frame located inside the tank and on which the needle holder plate is placed.
[0020] A shelf positioned on the supporting frame in an inclined fashion in such a way that the needle holder plate, when it is positioned on the shelf, is inclined with its front part, coinciding with the working part from which the needles protrude, positioned at a height lower than that rear part.
[0021] This arrangement is important in order to guarantee a complete washing of the needle holder plate and a correct drainage of the washing fluid and the dirt through the grooves and their escape through the working side.
[0022] Once the needle holder plate is positioned on the inclined surface, they are pushed manually, applying force on the respective "plate", so that needles slide along the grooves towards a contact bar.
[0023] When the working ends of the needles reach the contact bar and the needles remain in the inclined configuration a dispensing device, equipped with nozzles which are able to direct a jet of washing fluid towards the needle holder plates, starts the washing procedure moving forwards and backwards along washing lines with directions parallel to the longitudinal axis of the needle holder plate and parallel to each other in such a way as to cover the entire surface of the plate.
[0024] In order to reach all the various longitudinal feed and return directions, the dispensing device, once it has travelled completely along the first washing line, moves transversally to reach another washing line which it travels along in the opposite direction.
[0025] And so on until having completed the washing of the entire surface of the needle holder plate.
[0026] The two embodiments described above, although they are extremely reliable and efficient systems, have several drawbacks of a mechanical and practical nature.
[0027] With regard to the first embodiment, it is clear that the cam movement device of the movable carriage which selectively couples each tooth of the plate and allows the movement forwards and backwards of each needle into the respective seat or groove constitutes, simultaneously, a rotoidal and prismatic pair which requires maintenance and is also expensive.
[0028] With regard to the second embodiment, it is evident that the manual movement of the needles inside and along the grooves is not a practical, fast and efficient solution.
[0029] Moreover, with regard to the use of the nozzles, in the first case these cannot be oriented and cannot, therefore, be optimised on the basis of the model and the manufacture of the needle holder plates, and in the second case they require a very complex movement system which, however, does not protect it against damage.
[0030] It should also be noted during recent times these solutions are even more complex and uneconomic since the problem of cleaning the needle holder heads has been further complicated in recent years with the arrival on the market of new needle holder heads which are even more complex, where the hook shaped end of each needle acts in conjunction with another hook-shaped movable element, called "jack" in the jargon of the trade, to make the jacquard type twisted threads. The new components, in effect, tend to obstruct the escape of fluff from the rectilinear transversal grooves, and to compact even more deeply the fluff on the bottom of the grooves.
[0031] The aim of this invention is to provide a unit and a method for washing needle holder plates for knitting machines which overcomes the above-mentioned drawbacks of the prior art.
[0032] More specifically, the aim of this invention is to provide a unit and a method for washing needle holder plates for knitting machines which are able to remove the deepest and most compact deposits of fluff without the use of complex mechanical devices for moving the needles along their grooves and without the need for manual intervention by the operator.
[0033] These aims are fully achieved by the unit and by the method for washing needle holders plates for knitting machines according to the invention, as characterised in the appended claims.
[0034] More specifically, a unit for washing needle holder plates for knitting machines, the latter comprising a tank with a longitudinal main axis of extension and comprising therein a supporting shelf, a rectangular needle holder plate which extends along the direction of the longitudinal axis of the tank and is positioned on the supporting shelf, the needle holder plate comprising a plurality of grooves which extend transversely to the axis of the tank and one after the other, closed on one side and open on an operating side, a plurality of needles, each of which is positioned in the respective groove and is free to move along the groove, protruding partly on the operating side to then retract completely, characterised in that the washing unit comprises a washing head, a device for supporting the washing head comprising a first guide which extends in longitudinal direction parallel to the longitudinal axis of the tank, and a second guide which extends in a direction transversal perpendicular to the first, the head supporting device may performs a first sliding with a first law of motion along the first guide in both the forward and return directions, the washing head is mounted slidably on the second guide and perform a second sliding with a second law of motion along the second guide in both directions; the washing head comprises at least one first nozzle able to generate a first jet of washing liquid directed and oriented perpendicularly towards the needle holder plate, and at least one second nozzle able to generate a second washing jet directed and oriented inclined towards the needle holder plate; the first and second jet extend in a lying plane perpendicular to the longitudinal axis of the tank; the complete execution of the first sliding of the device for supporting the washing head and of the second sliding of the washing head, carrying out the combination of the first and of the second law of motion, allows the washing unit to wash the needle holder plate effectively.
[0035] This and other features will become more apparent from the following description of a preferred embodiment of the invention, illustrated by way of non-limiting example in the accompanying tables of drawings, in which:
- Figure 1 is a schematic plan view of a washing tank for knitting machines equipped with a washing unit according to this invention, in which the needlebed has the needles completely inserted inside respective grooves;
- Figure 2 illustrates the washing head with the first and the second nozzle open;
- Figure 3 illustrates the washing head with the first and the third nozzle open;
- Figure 4 is a schematic plan view of the washing tank for knitting machines of Figure 1 equipped with a washing unit according to this invention, in which the needlebed has the needles partially extracted from the respective grooves at the work side of the needlebed;
- Figure 5 shows a schematic perspective view of the washing head:
- Figure 6 is a cross section of the washing head of Figure 5 illustrating the valve device with the shutter piston;
- Figure 7 is a partial schematic perspective view of the tank of Figure 1 with the washing unit according to this invention.
[0036] The washing unit 1 uses an innovative washing head 2 based on a multi nozzle system, with tendentially different pressures, amplitudes and orientations. The activation of the nozzle is performed thanks to a mechanical system directly implemented on the nozzle mounting head and triggered by simply reaching the stroke end.
[0037] The pressurised jets of cleaning liquid may be generically classified as:
- Low pressure and full jet - the purpose is to pre-wash the surfaces and soften the dirt;
- Medium pressure jet and medium amplitude - has the purpose of removing the surface layer of dirt and evacuating effectively what has been removed by it and the high pressure jet.
- High pressure jet and localised amplitude - has the purpose of completely removing the dirt not yet removed by the medium pressure and already treated with the previous nozzles. Thanks to the high pressure it may reach even the narrowest and most hidden areas.
[0038] The operation of the machine comprises starting up the washing cycle in the direction longitudinal to the tank using at least a low pressure jet and at least a medium pressure jet: the dirt is pre-treated by the low pressure and the less stubborn part is removed and evacuated by the medium pressure. The head carrying device is moved to the end of the stroke in a transversal direction, the mechanical system deactivates the low pressure jet and activates the high pressure jet: the more stubborn dirt or that which is difficult to reach is finally removed and evacuated towards the tank of the hydraulic system.
[0039] On the areas where damage is likely due to the high pressure jet, the cleaning cycle is performed solely using the low and medium pressure washing head configuration.
[0040] The first advantage lies in the availability of jets of cleaning liquid which are suitable for washing any type of dirt present in knitting machines in the fabric production area.
[0041] The second advantage lies in the availability of jets of cleaning liquid which are suitable for washing any type of metal and plastic component present in knitting machines in the fabric production area.
[0042] The third advantage lies in the further optimisation of the timing and the effectiveness of the pressurised jets since several washing steps are no longer necessary as pre-washing, cleaning and discharging are carried out almost at the same time (superposed steps).
[0043] The fourth advantage lies in the simplicity and optimisation of the change of washing configuration of the nozzles which requires simply the mechanical movement of the piston which passes through the washing head, a movement already provided for the correct reaching of the various areas to be washed. The innovation of the washing head therefore allows the complete elimination of systems dedicated to the change of configuration of the active needles.
[0044] Guards are not required to prevent damage since the above-mentioned innovations provide pressurised jets suitable for each condition and simplify the implementation of a program for the complete control of the head carrying device and the relative jets.
[0045] As illustrated in the accompanying drawings, the unit 1 for washing plates 3 of needle holders 4 is designed to be mounted on knitting machines.
[0046] The latter comprising a tank 5 with a main longitudinal axis 6 of extension which comprises inside it a support shelf 7.
[0047] A plate 3 for needle holders 4 which is rectangular in shape that extends along the direction of the longitudinal axis 6 of the tank 5 is positioned on the support shelf 7.
[0048] The needle holder plate comprises a plurality of grooves 8 which extend transversely to the axis of the tank. They are positioned one after another and are closed on one side 9 and open on a working side 10.
[0049] A plurality of needles, each of which is positioned inside the respective groove, is free to move along the groove itself coming out partly from the working part 10 and then re-entering completely.
[0051] The supporting device comprises a first guide 11 extending in a longitudinal direction parallel to the longitudinal axis of the tank and a second guide extending in a transversal direction perpendicular to the first.
[0052] The device for supporting the head can perform a first sliding with a first law of motion along the first guide in both the forward F1 b and return F2b directions.
[0053] The washing head is mounted slidably on the second guide 12 and may perform a second sliding with a second law of motion along the second guide in both directions, F1a and F2a.
[0054] The washing head 2 comprises at least one first nozzle 13 able to generate a first jet 13a of washing liquid directed and oriented perpendicularly towards the needle holder plate, and at least one second nozzle 14 able to generate a second washing jet 14a directed and oriented inclined towards the needle holder plate.
[0055] The first and the second jet extend in a plane lying perpendicular to the longitudinal axis of the tank.
[0056] It should be noted that the complete execution of the first sliding of the device for supporting the washing head and of the second sliding of the washing head, carrying out the combination of the first and of the second law of motion, allows the washing unit to wash the needle holder plate effectively.
[0057] The washing head comprises a third nozzle 15 positioned on the opposite side of the second nozzle 14 relative to the first 13, and able to generate a third washing jet 15a directed and oriented inclined towards the needle holder plate, in mirrored direction relative to the second washing jet and lying on the same lying plane.
[0058] More specifically, the washing head comprises a valve body 16 with an inlet for the washing liquid and three paths for feeding the first, second and third nozzle.
[0059] A piston shutter 17 positioned inside the valve body can move between two positions along a seat made in the valve body and defined by a first end position wherein it opens the first and the second nozzle, thus closing the third nozzle, and a second end position wherein it opens the first and the third nozzle, thus closing the second nozzle.
[0060] It should be noted that in performing the first sliding along the first guide, the device for supporting the head reaches a first and a second operating end position.
[0061] Whilst in performing the second sliding along the second guide, the washing head also reaches a first and a second operating end position.
[0062] The first operating end position reached by the supporting device coincides with the first operating end position of the head to which corresponds the first operating end position of the shutter piston, with subsequent opening of the first and second nozzle;
[0063] While the second operating end position reached by the supporting device coincides with the second operating end position of the head to which corresponds the second operating end position of the shutter piston, with subsequent opening of the first and third nozzle and closing of the second nozzle.
[0064] At the first operating end position reached by the supporting device and at the first operating end position reached by the washing head, the first nozzle generates the first jet of fan-spray type and the second nozzle generates the second full cone jet directed inclined towards the side of the needle holder plate wherein the grooves are closed and the needles remain completely inside the respective grooves without moving along them.
[0065] At the second operating end position reached by the supporting device and at the second operating end position reached by the washing head, the first nozzle generates the first jet of fan-spray type and the third nozzle generates the third full cone jet directed inclined towards the side of the needle holder plate wherein the grooves are open and pushes the needles towards their partly extracted position from the relative grooves with subsequent movement of the needles and increased washing effectiveness of the grooves and of the needles.
[0066] The first nozzle has a full fan-spray jet with low flow rate whereby the force which it applies on the surface of the needle holder plate is relatively low, the second nozzle has a full cone jet which is cylindrical in shape and is at average flow rate with pressure on the needle holder plate greater than the other jets; the third nozzle has a higher flow rate factor than the others and average pressure.
[0067] The second jet and the third jet leave their relative nozzles while forming an alpha angle with the first jet; the alpha angle can vary between 25° and 55°, preferably 45°.
[0068] The above-mentioned first sliding of the device for supporting the head and the second sliding of the washing head are carried out simultaneously with the operation of the first nozzle.
[0069] Whilst the operation of the second nozzle occurs for the entire time during which the first sliding of the washing head support is performed in the first delivery direction between the first and the second operating end position.
[0070] Lastly, the operation of the third nozzle occurs for the entire time during which the first sliding of the washing head support is performed in the second return direction between the second and the first operating end position.
[0071] Figure 1 is a schematic view from above of the tank for containing the washing unit of the needlebeds. The tank has a longitudinal axis, parallel to which extend two guides for the supporting and sliding of a supporting device.
[0072] The movement of the supporting device both from left to right (1st longitudinal direction F1 b) and from right to left (2nd longitudinal direction F2a) - for someone observing, obviously, Figure 1 - is achieved by an endless belt 18 trained around two end pulleys and moved by motor means (the belt and the motor means are not illustrated).
[0073] When the washing head, sliding along its transversal supporting rod (piston without stem), moves to its 1 st transversal position F1a, the piston makes contact on a first stop and moves into the position shown in Figure 2.
[0074] In this position, the first vertical nozzle with the first flow or fan-spray jet and a second nozzle inclined at an angle to the vertical of the first jet are opened.
[0075] At this point, the device starts to move along the first longitudinal direction and carries out a first washing of the needlebed with the 1st and the 2nd nozzle.
[0076] After reaching to the right of Figure 1, and after carrying out the first washing step, the head moves to its 2nd transversal position F2a.
[0077] The piston encounters the second contact element, runs inside the washing head closing the 2nd nozzle and opening the third nozzle
Reference is made to the Figure 3.
1. A unit for washing needle holder plates for knitting machines, the latter comprising
a tank with a longitudinal main axis of extension and comprising therein a supporting
shelf, a rectangular needle holder plate which extends along the direction of the
longitudinal axis of the tank and is positioned on the supporting shelf, the needle
holder plate comprising a plurality of grooves which extend transversely to the axis
of the tank and one after the other, closed on one side and open on an operating side,
a plurality of needles, each of which is positioned in the respective groove and is
free to move along the groove, protruding partly on the operating side to then retract
completely, characterised in that the washing unit comprises a washing head, a device for supporting the washing head
comprising a first guide which extends in longitudinal direction parallel to the longitudinal
axis of the tank, and a second guide which extends in a direction transversal perpendicular
to the first; the device for supporting the head can perform a first sliding with
a first law of motion along the first guide in both forward and return directions,
the washing head is mounted slidably on the second guide and perform a second sliding
with a second law of motion along the second guide in both directions; the washing
head comprises at least one first nozzle able to generate a first jet of washing liquid
directed and oriented perpendicularly towards the needle holder plate, and at least
one second nozzle able to generate a second washing jet directed and oriented inclined
towards the needle holder plate; the first and second jet extend in a lying plane
perpendicular to the longitudinal axis of the tank; the complete execution of the
first sliding of the device for supporting the washing head and of the second sliding
of the washing head, following the combination of the first and of the second law
of motion, allows the washing unit to wash the needle holder plate effectively.
2. The washing unit according to claim 1, wherein the washing head comprises a third
nozzle positioned on the opposite side of the second nozzle relative to the first,
and able to generate a third washing jet directed and oriented inclined towards the
needle holder plate, in mirrored direction relative to the second washing jet and
lying on the same lying plane.
3. The washing unit according to claim 2, wherein the washing head comprises a valve
body with an inlet for the washing liquid and three paths for feeding the first, second
and third nozzle; a piston shutter positioned inside the valve body can move between
two positions along a seat made in the valve body and defined by a first end position
wherein it opens the first and the second nozzle, thus closing the third nozzle, and
a second end position wherein it opens the first and the third nozzle, thus closing
the second nozzle.
4. The washing unit according to one of claims 1 to 3, wherein in performing the first
sliding along the first guide, the device for supporting the head reaches a first
and a second operating end position; and wherein in performing the second sliding
along the second guide, the washing head also reaches a first and a second operating
end position; the first operating end position reached by the supporting device coincides
with the first operating end position of the head to which corresponds the first operating
end position of the shutter piston, with subsequent opening of the first and second
nozzle; while the second operating end position reached by the supporting device coincides
with the second operating end position of the head to which corresponds the second
operating end position of the shutter piston, with subsequent opening of the first
and third nozzle and closing of the second nozzle.
5. The washing unit according to any one of claims 1 to 4, wherein at the first operating
end position reached by the supporting device and at the first operating end position
reached by the washing head, the first nozzle generates the first jet of fan-spray
type and the second nozzle generates the second full cone jet directed inclined towards
the side of the needle holder plate wherein the grooves are closed and the needles
remain completely inside the respective grooves without moving along them; while at
the second operating end position reached by the supporting device and at the second
operating end position reached by the washing head, the first nozzle generates the
first jet of fan-spray type and the third nozzle generates the third full cone jet
directed inclined towards the side of the needle holder plate wherein the grooves
are open and, under the action thereof, pushes the needles towards their partly extracted
position from the relative grooves with subsequent movement of the needles and increased
washing effectiveness of the grooves and of the needles.
6. The washing unit according to any one of claims 1 to 5, wherein the first nozzle has
a full fan-spray jet with low flow rate whereby the force which it applies on the
surface of the needle holder plate is relatively low, the second nozzle has a full
cone jet which is cylindrical in shape and is at average flow rate with pressure on
the needle holder plate greater than the other jets; the third nozzle has a higher
flow rate factor than the others and average pressure.
7. The washing unit according to any one of claims 1 to 6, wherein the second jet and
the third jet leave their relative nozzles while forming an alpha angle with the first
jet; the alpha angle can vary between 25° and 55°, preferably 45°.
8. The washing unit according to any one of claims 1 to 7, wherein the first sliding
of the device for supporting the head and the second sliding of the washing head occur
simultaneously to the operation of the first nozzle, while the operation of the second
nozzle occurs for the entire time during which the first sliding of the washing head
support is performed in the first delivery direction between the first and the second
operating end position, and the operation of the third nozzle occurs for the entire
time during which the first sliding of the washing head support occurs in the second
return direction between the second and the first operating end position.
9. A knitting machine, characterised in that it uses a washing unit according to any one of claims 1 to 8.