Sewing machine

Abstract

The present invention relates to a weaving machine 100 comprising a base 1, configured to support a fabric, an upper arm 2, facing the base 1 and arranged at a predetermined vertical height with respect to the base 1. The weaving machine 100 further comprises an inner chamber comprising an upper portion, at least partially defined by the upper arm 2, and a lower portion, at least partially defined by the base 1, and a working assembly 200, operating between the base 1 and the upper arm 2, configured to carry out a processing of the fabric, at least partially mounted within the upper and lower portion. The weaving machine 100 also comprises a lubrication assembly for dispersing the lubricating liquid within the lower portion of the inner chamber. In greater detail, the lubrication assembly is arranged within the lower portion and the upper portion is fluid-dynamically separated from the lower portion.

Description

[0001] DESCRIPTION

[0002] TITLE:s SEWING MACHINE

[0003] Technical field

[0004] The present invention relates to a weaving machine.

[0005] In particular, the present invention relates to an industrial or domestic weaving machine for processing fabrics.

[0006] For example, the weaving machine subject-matter of the present invention is a machine for processing fabrics by sewing. In other words, the weaving machine allows carrying out stitching points on a fabric, or on a plurality of fabrics for them to be sewn together.

[0007] In other words, the present invention is part of the field of the processing of fabric, or of other similar materials, carrying out at least one processing thereon such as, for example, stitching points.

[0008] In a second aspect, the present invention relates to a fabric tension control system in a weaving machine.

[0009] In particular, in the second aspect, the present invention relates to a weaving machine having a voltage control system comprising electronic actuators managed by a control unit. The weaving machine in which the tension control system is provided is for example a "reverse arm" sewing machine.

[0010] Background art

[0011] Generally, a weaving machine comprises a body, which externally defines a base, configured to support a fabric being processed, and an upper arm upperly facing the base.

[0012] The body internally comprises a cavity, to define an inner chamber, comprising an upper portion, at least partially defined by the upper arm, and a lower portion, at least partially defined by the base.

[0013] Generally, a weaving machine comprises a working assembly, operating between the base and the upper arm, in such a way as to carry out a processing of the fabric arranged on the base. In greater detail, the working assembly is at least partially mounted within the inner chamber.

[0014] The body also comprises a casing arranged as a connection between the base and the upper arm, intended to contain transmission belts, in turn intended to move the working assembly.

[0015] In particular, the working assembly comprises a fabric conveying assembly, arranged at the base, configured to intercept and move the fabric being processed.

[0016] The working assembly may comprise, in an embodiment in which the weaving machine is a sewing machine, a needle, arranged at the upper arm and facing the conveying assembly, movable between a rest configuration, in which it is spaced apart with respect to the conveying assembly, and a work configuration, in which it is arranged at the conveying assembly to intercept the fabric being processed, thereby contributing to carrying out a stitching point on the fabric being processed. The working assembly may comprise, in an embodiment in which the weaving machine is a sewing machine, a crochet intended to carry out in cooperation with the needle a stitching point.

[0017] Generally, the working assembly further comprises a movement mechanism, configured to actuate the needle and / or the fabric conveying assembly, together with the thread necessary to carry out one or more stitching points.

[0018] Nowadays, the movement mechanism comprises a motorized member arranged outside the body, disadvantageously defining excessive overall dimensions, as well as generating unwanted vibrations.

[0019] The movement mechanism is actuatable by means of the motorized member, in such a way as to define a respective actuation of the needle and / or of the conveying assembly, together with the thread.

[0020] In greater detail, the movement mechanism comprises a plurality of rotating and / or translating components, such as for example shafts or levers, in contact with each other. Thus, when the movement mechanism is actuated, its rotating and / or translating components are in a relative sliding condition.

[0021] In order to avoid a machine seizure, as well as to decrease the wear of the movement mechanism, and therefore in order to reduce the costs related to the maintenance of a weaving machine, it is known to arrange a lubrication system within the inner chamber.

[0022] In order to decrease a torque necessary for an actuation of the working assembly, it is known to arrange a lubrication system within the inner chamber.

[0023] Nowadays, the lubrication system provides a forced lubrication made by means of a lubricating liquid, such as an oil, within the inner chamber, in such a way that the lubricating liquid is deposited on said rotating and / or translating components in relative sliding, reducing a friction between the same.

[0024] The dispersion of oil within the inner chamber requires an integration of sealing devices within the weaving machine, in such a way as to avoid any leaks.

[0025] Disadvantageously, the integration of sealing devices within the weaving machine causes an increase in the production and maintenance costs of the same.

[0026] In addition, a sealing device may be subject to malfunctions, and therefore to leaks.

[0027] Disadvantageously, in the event that the sealing device is positioned at the upper arm, facing the base that supports the fabric being processed, any leak would cause damage to the fabric being processed, causing a product to be discarded due to the fouling of the same by the lubricating liquid. As a result, these leaks lead to an increase in the costs for the production and the procurement of the raw material, i.e. of the fabric.

[0028] Object of the Invention

[0029] Therefore, the technical task underlying the present invention is to propose a weaving machine that overcomes the drawbacks that have emerged from the known art.

[0030] In particular, aim of the present invention is to propose a weaving machine that prevents leaks of lubricating liquid, while maintaining efficient lubrication.

[0031] Aim of the present invention is also to propose a weaving machine that allows a saving in terms of costs for the production of the fabric product and for the procurement of fabric to be processed.

[0032] Aim of the present invention is also to propose a weaving machine that allows a saving in terms of production and maintenance costs thereof.

[0033] In a second aspect, aim of the present invention is to propose a tension control system, particularly for "reverse arm" weaving machines, having reduced overall dimensions in the stitching zone, which must be minimal in order to be able to thread the fabric to produce a sleeve or a sock, and / or the like.

[0034] Brief description of the drawings

[0035] The specified technical task and the specified objects are substantially achieved by a weaving machine comprising the technical features set forth in one or more of the appended claims.

[0036] The dependent claims correspond to possible embodiments of the invention.

[0037] Further features and advantages of the present invention will become more apparent from the approximate and thus non-limiting description of a preferred, but non-exclusive, embodiments of a weaving machine.

[0038] This description will be set forth below with reference to the attached drawings, provided for indicative and, therefore, non-limiting purposes, in which:

[0039] - Figure 1 shows a schematic view of a weaving machine subject-matter of the present invention;

[0040] - Figure 2 shows the weaving machine of Figure 1 mounted on a bench;

[0041] - Figure 3 shows a schematic view of a lower portion of an inner chamber of the weaving machine subject-matter of the present invention; - Figure 4 shows a partially sectional view of a weaving machine subject- matter of the present invention;

[0042] - Figures 5 to 10 show schematic representations of different components of the weaving machine subject-matter of the present invention;

[0043] - Figure 11 shows a schematic representation of the electronic differential device of Figure 9;

[0044] - Figure 12 schematically shows the different adjustment speeds of the front claw.

[0045] Detailed description of preferred embodiments of the invention

[0046] The present invention provides a weaving machine 100, illustrated in Figure 1.

[0047] The weaving machine 100 comprises a base 1 , defining a rest portion 1a and configured to support a fabric, and an upper arm 2, facing the base 1 and arranged at a predetermined vertical height with respect to the base 1 . The term "vertical height" means a height measured along a normal direction, perpendicular to the base 1 , starting from the rest portion 1 a.

[0048] In other words, the upper arm 2 is spaced apart from the base 1 along an axis perpendicular to the base 1 itself, and defines with the base 1 a working space "S",

[0049] As illustrated in Figure 2, the weaving machine 100 is mountable on a bench 1000, such that it is stably maintained in an elevated position.

[0050] Advantageously, the bench 1000 allows to support a portion of a fabric being processed, after processing it.

[0051] Advantageously, the bench 1000 allows to maintain the weaving machine 100 at a position that is functional to an operator tasked to interact with the weaving machine 100.

[0052] The weaving machine 100 comprises an inner chamber 4, comprising an upper portion 4a (schematically represented in Figure 6), and a lower portion 4b, illustrated in Figure 3.

[0053] In greater detail, the upper portion 4a is at least partially defined by the upper arm 2. In other words, the upper arm 2 comprises a respective inner cavity, defining the upper portion 4a of the inner chamber 4.

[0054] The lower portion 4b is at least partially defined by the base 1 , in other words, the base 1 comprises a respective inner cavity, defining the lower portion 4b of the inner chamber 4.

[0055] Preferably, the upper portion 4a and the lower portion 4b are communicating with each other.

[0056] With reference to the attached figures, the weaving machine 100 comprises a working assembly 200 operating between the base 1 and the upper arm 2, in other words the working assembly 200 operates within the working space "S".

[0057] The working assembly 200 is configured to carry out a processing of the fabric arranged on the base 1.

[0058] In greater detail, the working assembly 200 is at least partially mounted within the upper portion 4a and the lower portion 4b.

[0059] In other words, the working assembly 200 is at least partially mounted within the inner chamber 4, thus the working assembly 200 is at least partially arranged within the cavities of the base 1 and of the upper arm 2, respectively.

[0060] The weaving machine 100 further comprises a lubrication assembly 300, illustrated in Figures 3-5.

[0061] The lubrication assembly 300 comprises a pumping member 301 , i.e. a device adapted to pressurize a liquid, and a tank 302, configured to contain a lubricating liquid therein. In other words, the pumping member 301 is configured to pressurize the lubricating liquid.

[0062] The pumping member 301 and the tank 302 are in fluid communication with each other, so as to disperse the lubricating liquid in the lower portion 4b of the inner chamber 4.

[0063] In other words, the lubrication assembly 300 is configured to carry out a lubrication of a portion of the working assembly 200 arranged within the inner chamber 4, in particular within the lower portion 4b of the inner chamber 4.

[0064] Therefore, the lubrication assembly 300 is configured to disperse lubricating liquid on the portion of the working assembly 200 arranged within the lower portion 4b of the inner chamber 4, so as to carry out its lubrication.

[0065] In greater detail, the lubrication assembly 300 is arranged within the lower portion 4b, in other words, the pumping member 301 and the tank 302 are arranged within the lower portion 4b of the inner chamber 4. Preferably, the tank 302 is at least partially defined by the lower portion 4b itself.

[0066] Further, the upper portion 4a and the lower portion 4b are fluid- dynamically separated from each other.

[0067] In other words, the lubricating liquid dispersed by the lubrication assembly 300 within the lower portion 4b cannot reach the upper portion 4a.

[0068] Advantageously, the fluid-dynamic separation between the upper portion 4a and the lower portion 4b, together with the positioning of the lubrication assembly 300 within the lower portion 4b, prevent leaks by gravity of lubricating liquid through the upper arm 2, from the inner chamber 4 to the base 1.

[0069] In other words, the weaving machine 100 prevents losses of lubricating liquid that may affect the fabric being processed, arranged at the base 1. Advantageously, moreover, the above technical characteristics guarantee a saving in terms of costs for the production of the fabric product and costs for the procurement of fabric to be processed as the weaving machine 100 allows to prevent the fabric from being fouled by the lubricating liquid.

[0070] With reference to the lubrication assembly 300 and Figure 4, the lower portion 4b of the inner chamber 4 comprises the tank 302 and a side compartment 40 which are separated by a wall "P".

[0071] With reference to Figure 4, the lower chamber 4b comprises a portion 41 intended to contain a crochet for moving and thus feeding the thread to the working assembly 200. Therefore, the portion 41 is lubrication-free to prevent damage to the thread and is separated from the rest of the lower chamber 4b by means of the wall "P". In other words, the wall "P" isolates the portion 41 from the rest of the lower chamber 4b so as to prevent the oil from creeping into the portion 41.

[0072] The pumping member 301 is positioned within the tank 302 and is connected or connectable to the working assembly 200, such that an actuation of the working assembly 200 corresponds to an actuation of the pumping member 301.

[0073] Preferably, the pumping member 301 comprises a gear pump.

[0074] In greater detail, the lubrication assembly 300 comprises a tube 303, fluid- dynamically connected to the pumping member 301 and to the side compartment 40, while the wall "P" comprises a cavity 400 arranged as a connection between the tank 302 and the side compartment 40, configured to house the tube 303.

[0075] As depicted, for example, in Figure 4, the portion 41 is arranged at the top with respect to the cavity 400 (i.e. with respect to the tube 303).

[0076] With reference to Figures 3 and 5, the lubrication assembly 300 further comprises a lubrication plate 304 and a diffuser 305 facing each other and arranged to close the side compartment 40 at the top.

[0077] In greater detail, the diffuser 305 is arranged lower than the lubrication plate 304 and an open end of the tube 303 faces the lubrication plate 304 and the diffuser 305, so as to pour lubricating liquid at the lubrication plate 304 and to disperse the same by means of the diffuser 305 into the side compartment 40.

[0078] The diffuser 305 comprises a plurality of holes, therefore the lubricant is diffused into the lower portion 4b by falling through the holes.

[0079] As illustrated in Figure 4, the cavity 400 comprises a first open end facing the tank 302 and a second open end facing the side compartment 40, as well as a diameter greater than a diameter of the tube 303.

[0080] In detail, the first end is arranged at a vertical height lower than a vertical height of the second end.

[0081] Thus, a recirculation of oil from the side compartment 40 to the tank 302 occurs by gravity.

[0082] The weaving machine 100 comprises, within the upper portion 4a of its inner chamber 4, at least one bearing 5, illustrated in Figure 6.

[0083] In more detail, the bearing 5 is connected to the working assembly 200.

[0084] In other words, the bearing 5 is connected to a portion of the working assembly 200 arranged within the upper portion 4a of the inner chamber 4, so as to achieve a low friction coupling with a respective component of the working assembly 200.

[0085] In accordance with an embodiment of the present invention, the bearing 5 requires a slight initial lubrication with grease or oil, prior to mounting the weaving machine 100.

[0086] Advantageously, the bearing 5 replaces a lubrication made by forced lubrication of lubricating oil within the upper portion 4a of the inner chamber 4, preventing a possible seizure of the weaving machine 100, as well as the wear of its components.

[0087] Advantageously, the bearing 5 allows to prevent any leak by gravity of lubricating liquid from the upper portion 4a to the fabric being processed, supported on the base 1 .

[0088] Advantageously, moreover, the bearing 5 guarantees a saving in terms of costs for the production of the fabric product and costs for the procurement of fabric to be processed.

[0089] The bearing 5 avoids a need for integration of sealing devices within the weaving machine 100, at least at the upper portion 4a of its inner chamber 4.

[0090] Therefore, advantageously, the bearing 5 also ensures a saving in terms of production and maintenance costs of the weaving machine 100, and avoids a need for expensive and complicated mechanical machining for a realization of the weaving machine 100.

[0091] According to a further embodiment, by bearing 5 it can be meant a device that does not require any addition of oil or grease prior to mounting the weaving machine 100. For example, the bearing 5 comprises or can be made in the form of a low friction coefficient sliding bearing, or a rolling bearing.

[0092] In the embodiment illustrated in Figure 6, the bearing 5 is made in the form of a rolling bearing, in other words a first bearing 5 (on the left with reference to Figure 6 itself) is made in the form of a roller shell while a second bearing 5 (on the right with reference to Figure 6 itself) is made in the form of a ball bearing.

[0093] Advantageously, the aforementioned components ensure a high useful life, possibly with an initial lubrication of the same after mounting within the weaving machine 100.

[0094] In accordance with a further embodiment, the bearing 5 is made in the form of a sliding bearing, produced through a powder compaction process, i.e. through a sintering process.

[0095] Preferably, the sintering process is followed by a process of impregnation with a lubricating liquid such that when the weaving machine 100 is in use, the lubricating liquid contained in the bearing 5 is released thanks to the heat dispersed by the friction between the bearing 5 itself and other components of the weaving machine 100.

[0096] Therefore, thanks to the bearing 5, a dispersion of lubricating liquid within the upper portion 4a is not required, whereas with the stationary weaving machine 100, the lubricating liquid is reabsorbed by the porosity of the bearing 5.

[0097] Even more preferably, the bearing 5 is made of sintered bronze, which, advantageously, is a material suitable for applications in a weaving machine 100, i.e. for applications with high speeds and low loads, as well as suitable for allowing hydrodynamic lubrication during an intermittent, i.e. oscillating, rotation motion.

[0098] In accordance with one embodiment, the bearing 5 is made of polymeric material of aeronautical derivation, advantageously able to withstand high frequency stresses.

[0099] With reference to Figure 6, the working assembly 200 comprises an upper shaft 201 , developing along a respective development axis "X" substantially parallel to the base 1 .

[0100] In greater detail, the upper shaft 201 is arranged within the upper portion 4a and the bearing 5 is arranged around the upper shaft 201 .

[0101] Preferably, the upper shaft 201 is adapted to rotate about the development axis "X", in other words, the upper shaft 201 is adapted to rotate within the bearing 5.

[0102] Advantageously, the bearing 5 is in contact with the upper shaft 201 and allows, during a rotary and / or translational movement of the upper shaft 201 itself, a lubrication without dispersion of a lubricating liquid.

[0103] Preferably, the upper shaft 201 comprises a respective full section "A”. In other words, the upper shaft 201 does not comprise any channel or hole therein, advantageously ensuring a decrease in costs for producing the upper shaft 201 itself and consequently the weaving machine 100.

[0104] In order to allow, in a mounting step of the weaving machine 100, an assembly between the bearing 5 and the upper shaft 201 , the latter is composite, i.e. composed of a plurality of segments 201a, 201 b, as illustrated in Figure 6.

[0105] In greater detail, the upper shaft 201 comprises a pair of side segments 201a that are coaxial with each other, i.e. developing along the axis "X", and comprising, at respective ends facing each other, a housing seat "C", and a central segment 201 b, inserted or insertable into the housing seat "C" of each side segment 201a.

[0106] Preferably, the central segment 201 b and the side segments 201a are made by forging in special moulds.

[0107] Advantageously, the upper shaft 201 thus shaped ensures a decrease in the costs for producing the weaving machine 100.

[0108] Preferably, the central segment 201 b comprises a respective pair of side portions, each facing a side segment 201a, which are arranged eccentrically with respect to the axis "X".

[0109] The term "eccentric position” means that a centre or a central portion of the housing seat "C" does not lie along the development axis "X", i.e. it does not coincide with a centre of a section of the side segment 201a.

[0110] Preferably, the central segment 201b is inserted into the housing seat "C" of each side segment 201a by cold forcing. In other words, the central segment 201 b is mounted with the side segments 201a to form the upper shaft 201 by interference fit ensuring a reduced overall dimension during a realization of cold forcing.

[0111] With reference to the attached figures, and In particular Figures 9 and 10, the working assembly 200 may comprise at least one needle 202 facing the base 1 and movable along a vertical direction "X1" towards and away from the base 1 itself.

[0112] In other words, the needle 202 is movable along a direction normal to the base 1.

[0113] Therefore, the needle 202 is movable between a rest configuration, in which it is spaced apart from the base 1 , and a work configuration, in which it is arranged at the base 1 to intercept the fabric being processed arranged thereon, thereby contributing to carrying out a stitching point on the fabric being processed.

[0114] A movement of the needle 202 is imposed by means of a movement of the upper shaft 201 : with reference to Figure 6, the working assembly 200 in fact comprises a connecting rod "B1", connected to the upper shaft 201 and configured to carry out a respective movement of the needle 202.

[0115] Referring to Figure 7, the working assembly 200 further comprises a lever 203, interposed between the upper shaft 201 and the needle 202, configured to move the needle 202 along the vertical direction "XT' between the rest configuration and the work configuration as a function of a rotation of the upper shaft 201 .

[0116] The lever 203 is connected with the bearing 5.

[0117] Advantageously, the bearing 5 ensures a lubrication without dispersion of lubricating liquid in a portion close to the needle 202 of the weaving machine 100, preventing any leak at the needle 202 itself. 3

[0118] Consequently, the bearing 5 avoids a possible leak of lubricating liquid from the upper portion 4a, ensuring a decrease in costs for the production and procurement of fabric.

[0119] With reference to Figure 7, preferably, the lever 203 comprises a pair of side plates 203a, 203b facing each other and connected or connectable by means of pins 203c interposed between the side plates 203a, 203b themselves.

[0120] Advantageously, the lever 203, being composed of several components, i.e. the plates 203a, 203b and the pins 203c, guarantees a reduction in the costs for producing the same and, consequently, the weaving machine 100.

[0121] Even more preferably, the side plates 203a, 203b each comprise a housing seat 203d for the bearing 5.

[0122] Advantageously, the housing seat 203d ensures a correct positioning of the bearing 5 in a mounting step of the weaving machine 100, as well as a maintenance of the bearing 5 in the seat during a step of actuation of the weaving machine 100.

[0123] Similarly to the above upper shaft 201 , and with reference to Figure 8, the weaving machine 100 comprises a lower shaft 204 developing along a respective development axis "Y" substantially parallel to the base 1 .

[0124] The lower shaft 204 is mounted within the lower portion 4b of the inner chamber 4 (as visible in Figure 3 and Figure 4), and is lubricated by means of the lubrication assembly 300, i.e. by dispersion of lubricating liquid.

[0125] In greater detail, similarly to the upper shaft 201 , the lower shaft 204 is composite, i.e. it comprises a pair of side segments 204a that are coaxial with each other and comprising, at respective ends facing each other, a housing seat "D", preferably arranged in an eccentric position, and a central segment 204b, inserted or insertable into the housing seat "D" of each side segment 204a.

[0126] Preferably, the central segment 204b comprises a spherical portion thereof, connected to a respective connecting rod "B2" in such a way as to carry out a movement of the iatter.

[0127] The connecting rod "B2" is intended for moving a crochet of the weaving machine 100, in such a way as to carry out, in cooperation with the needle 202, a stitching point on a fabric being processed.

[0128] As schematically depicted in Figure 4, a portion of the lower shaft 204 is at least partially inserted into the portion 41 of the lower chamber 4b. In other words, at least one of the side segments of the pair of side segments 204a and at least part of the central segment 204b are contained within the portion 41.

[0129] Preferably, similarly to the upper shaft 201 , the central segment 204b and the side segments 204a are made by forging in special moulds, advantageously ensuring a reduction in production costs.

[0130] Preferably, similarly to the upper shaft 201 , the central segment 204b is inserted into the housing seat "D" of each side segment 204a by cold forcing.

[0131] Advantageously, the composite lower shaft 204 ensures a decrease in costs for producing the same and consequently the weaving machine 100. In accordance with one aspect of the present invention, and as illustrated in Figure 5, the lower shaft 204 is connected with the pumping member 301 by means of at least one pair of gears 7, made of reinforced technopolymer, such that an actuation of the working assembly 200 corresponds to an actuation of the pumping member 301.

[0132] In greater detail, the pair of gears 7 preferably comprises straight teeth and is actuated by a rotation of the lower shaft 204.

[0133] Advantageously, the reinforced technopolymer guarantees a reduction in costs for producing the weaving machine 100 as well as giving it a greater noiselessness.

[0134] According to one aspect of the present invention, and with reference to Figures 1-5, the weaving machine 100 comprises a servomotor 6, preferably of type direct-drive. Advantageously, the servomotor 6 is compact, ensuring a reduction in the overall dimensions of the weaving machine 100.

[0135] Even more advantageously, a servomotor of direct-drive type is economical, guaranteeing a reduction in the costs for producing the weaving machine 100, as well as efficient in that its power is transmitted with small losses, guaranteeing lower energy consumption and therefore reducing the costs for actuating the weaving machine 100.

[0136] The servomotor 6 is at least partially arranged within the inner chamber 4 and is connected or connectable to the working assembly 200 to actuate the same.

[0137] In greater detail, the weaving machine 100 further comprises a casing 3 arranged between the base 1 and the upper arm 2 and intended to at least partially house the servomotor 6. Furthermore, the casing 3 is adapted to contain transmission belts which are arranged as a connection between the servomotor 6 and the upper 201 and lower 206 shafts.

[0138] Preferably, the casing 3 is arranged in respective side portions, facing each other, of the base 1 and of the upper arm 2.

[0139] Advantageously, the servomotor 6 generates low vibrations and low noise, helping to reduce the fatigue of an operator interfacing with the weaving machine 100.

[0140] According to one aspect of the present invention and with reference to Figures 9 and 10, the working assembly 200 comprises a conveying assembly 206, at least partially arranged on the base 1 .

[0141] In greater detail, a movement of the conveying assembly 206 corresponds to a movement of the fabric, arranged on the base 1 , with respect to the base 1 itself.

[0142] The conveying assembly 206 comprises a pair of movable claws 206a, 206b. More in detail, the conveying assembly 206 comprises a front claw 206a, configured to feed a fabric and a rear claw 206b, configured to convey the fed fabric and to define a distance between two consecutive points. The conveying assembly 206 further comprises an electronic differential "M", configured to increase or decrease an amount of fabric fed by means of the front claw 206a.

[0143] The electronic differential "M" comprises a movable slider 207, connected to the front claw 206a, such that a movement of the slider 207 corresponds to a respective conveying speed of the fabric of the claw 206a.

[0144] Preferably, the slider 207 is connected to the front claw 206a.

[0145] In greater detail, the electronic differential "M" comprises an electric stepper motor 208 and a shaft, which are connected to each other by means of a pair of gears such that an actuation of the electric stepper motor 208 corresponds to a rotation of the pair of gears and thus of the shaft.

[0146] The electronic differential "M" further comprises a lever 210 interposed between the shaft and the slider 207, therefore the lever 210, when actuated by a rotation of the shaft, carries out a movement of the slider 207.

[0147] In more detail, it is possible to increase and decrease the stroke of the elliptical movement of the front claw 206a, consequently increasing or decreasing a conveying speed of the fabric.

[0148] The elliptical movement is illustrated by means of arrows "F" in Figure 10. Preferably, the conveying assembly 206 comprises a limit switch sensor configured to generate a signal representing a working area, i.e. an area in which the fabric is arranged.

[0149] According to one aspect of the present invention, the stepper electric motor 208, and consequently the electronic differential "M" and the conveying assembly 206, is managed in an electronic manner.

[0150] Advantageously, it is therefore possible to set a work configuration during a processing of the fabric.

[0151] With reference to the attached figures, preferably, the weaving machine 100 comprises a control unit 8 operatively connected with the working assembly 200 to drive an actuation thereof.

[0152] It is therefore possible to vary the conveying speed of the fabric of the front claw 206a according to a law configurable and implementable by means of the control unit 8, consequently commanding a variation in speed even during the sewing operation.

[0153] Advantageously, it is therefore possible to vary the conveying speed of the fabric during a processing of the same, carrying out different seams during the same work cycle.

[0154] Preferably, the weaving machine 100 comprises a user interface 9, configured to allow an operator to enter operating parameters of the weaving machine 100.

[0155] Even more preferably, the user interface 9 comprises a touch-screen display 9a.

[0156] Advantageously, the weaving machine 100 is able to overcome the drawbacks that have emerged from the known art.

[0157] Advantageously, the weaving machine 100 allows to prevent liquid leaks on the fabric being processed.

[0158] Advantageously, the weaving machine 100 therefore ensures a limitation of the costs for the production and the procurement of the raw material, i.e. of the fabric.

[0159] Advantageously, the weaving machine 100 guarantees low production and maintenance costs, as well as low costs related to its energy consumption. Advantageously, the weaving machine 100 is during use noiseless and is subject to low vibrations, promoting the well-being of an operator destined to its use.

[0160] In a second aspect, the present invention relates to a system for conveying and controlling the tension of the fabric in a weaving machine (electronic differential).

[0161] With reference to Figures 9 and 10, as described above, the working assembly 200 comprises a conveying assembly 206, at least partially arranged on the base 1 , wherein a movement of the conveying assembly 206 corresponds to a movement of the fabric with respect to the base 1 .

[0162] Preferably, the conveying assembly 206 comprises a pair of movable claws 206a, 206b, a movable slider 207, connected to at least one claw of the pair of claws 206a, 206b, wherein a movement of the slider 207 corresponds to a respective stroke of the claw 206a, 206b during a movement thereof.

[0163] A conveying shaft 220, a crank arm element 221 , a slider 22, a joint for differential slide 223 and a slide crank arm of the point 224 are part of the working assembly 206.

[0164] The fabric conveying system with the differentiated claws usually includes separate conveying mechanisms for each of the two claws, a front claw 206a (differential claw) and a rear claw 206b (claw of the point).

[0165] Both conveying mechanisms are commanded by a common drive shaft. This system is used more to solve some sewing defects, especially when light or elasticated fabrics are used.

[0166] Currently this type of mechanism is commanded manually by means of an adjustable positioning lever before sewing. By acting on this lever the speed with which the front claw moves is adjusted, while the rear one will always make the same rotation. This adjustment remains fixed during the sewing operation.

[0167] The present invention allows the conveying and tensioning system to be managed electronically. In this way, it is possible to vary the speed of the front claw 206a with a configurable law managed by a control unit. The advantage is that the system can be used even during the sewing operation.

[0168] One of the major innovations of the present invention is the implementation of the fabric tensioning device.

[0169] A fabric conveying system with differentiated claws includes separate conveying mechanisms for each of the two claws, one front (differential claw) and one rear (claw of the point). Both mechanisms are commanded by a common drive shaft.

[0170] This system is used more to solve some sewing defects, especially when light or elasticated fabrics are used. Currently this type of mechanism is commanded manually by means of an adjustable positioning lever before sewing. By acting on this lever the speed with which the front claw moves is adjusted, while the rear one will always make the same rotation. This adjustment remains fixed during the sewing operation.

[0171] The present invention allows to manage the fabric tensioning system electronically: in this way it is possible to vary the speed of the front claw with a configurable law managed by a control unit.

[0172] The advantage is that the system can be used even during the sewing operation.

[0173] The tensioning device is composed of an electric stepper motor 208 where a pair of toothed wheels constituting a gear 216 (or reducer) that transmit the motion to a first shaft 217 is connected. The shaft 217 moves a lever 218 which, during operation of the weaving machine, will displace the slider 222 and consequently the differential slide 226.

[0174] In this way, the rotation speed of the claw 206a of the differential will be increased or decreased.

[0175] Preferably, the fabric tensioning device comprises a limit switch sensor 215 configured to monitor the work area via a reader (Figure 11).

[0176] The conveying and tensioning device is composed of an electric stepper motor 208 where it is connected to a reducer composed of a gear, preferably two toothed wheels, which transmits the motion to a shaft 217.

[0177] The shaft 217 moves a lever 219 which will displace a slider 222 and consequently the differential slide 226. In this way, it will be possible to increase or decrease the rotation speed of the claw of the differential 206a.

[0178] In the conveying and tensioning device there is also a safety / limit switch sensor 215 that will monitor the work area through a reader 215a. Depending on the type of fabric it is possible to decide to set different rotation speeds of the front claw 206a.

[0179] Figure 12 illustrates, by way of non-limiting example, various rotation speeds of the front claw 206a with respect to the rear claw 206b.

[0180] For example, by selecting the setting parameter 2, the front claw 206a will rotate at twice the speed of the rear claw 206b, displacing much more fabric than the latter. Conversely, when the parameter is set to 0.7 value, the front claw 206a will displace a smaller amount of fabric than the rear claw 206b. In such a case, the rear claw 206b will stretch the fabric while it is being sewn. By selecting the parameter or value 1 , both claws 206a, 206b will move at the same speed.

[0181] In this way, through the electronic tensioning system it will be possible to vary the setting even during the sewing operation, establishing that the parameter can be changed after a precise number of sewing points.

[0182] Preferably, the weaving machine 100 according to one or more of the preceding claims, comprises a control unit 8 operatively connected with the working assembly 200 to drive an actuation thereof.

Claims

CLAIMS1. Weaving machine (100) comprising:- a base (1 ), configured to support a fabric;- an upper arm (2), facing the base (1 ) and arranged at a predetermined vertical height with respect to said base (1);- an inner chamber (4) comprising an upper portion (4a), at least partially defined by said upper arm (2), and a lower portion (4b) at least partially defined by said base (1);- a working assembly (200), operating between said base (1 ) and said upper arm (2), configured to carry out a fabric processing and at least partially mounted within said upper portion (4a) and said lower portion (4b);- a lubrication assembly (300) comprising a pumping member (301) and a tank (302), configured to contain a lubricating liquid, in fluid communication with each other so as to disperse the lubricating liquid in said lower portion (4b) of the inner chamber (4), characterized in that the lubrication assembly (300) is arranged within the lower portion (4b) and in that the upper portion (4a) is fluid-dynamically separated from the lower portion (4b).

2. Weaving machine (100) according to claim 1 , comprising, within the upper portion (4a), at least one bearing (5) connected to said working assembly (200).

3. Weaving machine (100) according to claim 1 or 2, wherein- the working assembly (200) comprises an upper shaft (201 ), developing along a respective development axis (X) substantially parallel to said base (1 ), arranged within the upper portion (4a), and wherein- the weaving machine (100) comprises at least one bearing (5) arranged around the upper shaft (201),said upper shaft (201 ) being adapted to rotate about said development axis (X) and / or being adapted to slide along the development axis (X).

4. Weaving machine (100) according to claim 3, wherein the working assembly (200) comprises:- a needle (202), facing the base (1), and movable along a vertical direction (X1 ) towards and away from the base (1 );- a lever (203), interposed between the upper shaft (201) and the needle (202), configured to move the needle (202) along said vertical direction (X1 ) as a function of a rotation of said upper shaft (201 ), and wherein the bearing (5) is interposed between the lever (203) and the upper shaft (201 ).

5. Weaving machine (100) according to claim 4, wherein the lever (203) comprises a pair of side plates (203a, 203b) facing each other and connected or connectable by means of pins (203c) interposed between the side plates (203a, 203b) themselves, said side plates (203a, 203b) each comprising a housing seat (203d) for a respective bearing (5).

6. Weaving machine (100) according to one or more of claims 3 to 5, wherein said upper shaft (201) comprises:- a pair of side segments (201 a) that are coaxial with each other and comprising, at respective ends facing each other, a housing seat (C);- a central segment (201 b), inserted or insertable into the housing seat (C) of each side segment (201a) of the pair of side segments (201a).

7. Weaving machine (100) according to one or more of the preceding claims, wherein the working assembly (200) comprises a lower shaft (204), developing along a respective development axis (Y) substantially parallel to said base (1), arranged within the lower portion (4b), said lower shaft (204) comprising a pair of side segments (204a) that are coaxial with eachother and comprising, in respective ends facing each other, a housing seat (D) and a central segment (204b), inserted or insertable within the housing seat (D) of each side segment (204a) of the pair of side segments (204a).

8. Weaving machine (100) according to one or more of claims 2-7, wherein the bearing (5) comprises a low friction coefficient sliding bearing, or a rolling bearing.

9. Weaving machine (100) according to one or more of the preceding claims, comprising a servomotor (6) at least partially arranged within the inner chamber (4) and connected or connectable to said working assembly (200) to actuate the working assembly (200) itself.

10. Weaving machine (100) according to one or more of the preceding claims, wherein the tank (302) of lubricating liquid is at least partially defined by means of the lower portion (4b), and wherein the pumping member (301) is connected or connectable to the working assembly (200) by means of at least a pair of gears (7), made of reinforced technopolymer, such that an actuation of the working assembly (200) corresponds to an actuation of the pumping member (301 ).

11. Weaving machine (100) according to one or more of the preceding claims, wherein the working assembly (200) comprises a conveying assembly (206), at least partially arranged on the base (1), wherein a movement of the conveying assembly (206) corresponds to a movement of the fabric with respect to the base (1 ).

12. Weaving machine (100) according to claim 11 wherein the conveying assembly (206) comprises:- a pair of movable claws (206a, 206b);- a movable slider (207), connected to at least one claw of the pairof claws (206a, 206b), wherein a movement of the slider (207) corresponds to a respective stroke of the claw (206a, 206b) during a movement thereof.

13. Weaving machine (100) according to one or more of the preceding claims, further comprising a control unit (8) operatively connected with the working assembly (200) to drive an actuation thereof.

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