Abstract: The thread guide structure for double-cylinder circular knitting machines comprises a thread guide body which has an elongated configuration and has, proximate to one of its longitudinal ends, a thread dispensing passage. The thread guide body has a first part and a second part which are mutually articulated proximate to an intermediate region of the thread guide body. The first part, which is provided with the thread dispensing passage, is oscillatable with respect to the second part about an oscillation axis which is arranged transversely to the longitudinal extension of the thread guide body.

Abstract: The thread feed unit has a supporting block which can be associated with a knitting machine laterally to the needle cylinder or cylinders and is provided with at least one thread guide which has a body provided with an elongated configuration associated with a supporting element and slidable along a direction substantially parallel to its longitudinal extension. The supporting element is associated with the supporting block for oscillation about an oscillation axis transverse to the sliding direction of the thread guide body. A first thread guide actuator is provided and controllably acts on the supporting element to oscillate the thread guide about the oscillation axis, and a second actuator controlling the thread guide body to slide it longitudinally with respect to the supporting element. The first actuator and the second actuator are associated with the supporting block and can be actuated independently of one another.

Abstract: The twin-cylinder circular knitting machine with knitted fabric tensioning device having members for retaining the fabric proximate to a knitting forming region. A first fluid-activated piston is accommodated in the upper needle cylinder and is provided with a hollow stem which is open at its ends. The lower end of the stem is engageable, by means of the sliding of the piston parallel to the axis of the needle cylinders, with the knitted fabric being formed in order to apply tension thereto. The retention members have dimensions for allowing the stem to slide outside of the retention members. The tensioning device also has an auxiliary actuation piston which acts on the piston to achieve its descent at a controlled rate at least until the lower end of the stem of the piston makes contact with the fabric in the region comprised between the retention members and the knitting forming region.

Abstract: The circular knitting machine has a pneumatic service circuit with pneumatically actuated service devices arranged around the needle cylinder. An annular body surrounds the needle cylinder, and a main duct is defined in the annular body. The main duct is supplied with pressurized air and is connected to the supply ducts of pneumatic actuators which actuate the service devices. Valve for operating the actuators are arranged between the actuator supply ducts and the main duct.

Abstract: The single-cylinder circular machine comprises a substantially vertical needle cylinder which is rotatable about an axis and supports a plurality of needles which are arranged in axial grooves of the outer skirt of the needle cylinder and can move individually along directions which are parallel to the needle cylinder axis. A platen is arranged coaxially above the needle cylinder and is supported, so as to be rotatable about the needle cylinder axis, by the supporting structure of the machine. The machine comprises first connecting members which can be controllably activated or deactivated in order to rigidly associate the platen, in its rotation about the axis, with the needle cylinder, and second connecting members arranged on a wing of the platen which extends inside the needle cylinder and on a portion of the inner surface of the needle cylinder which faces the wing.

Abstract: The direct drive circular knitting machine has a main structure rotatably supporting a needle cylinder having a needle cylinder axis. An electric motor is provided for rotating the needle cylinder with respect to the main structure about the needle cylinder axis. The electric motor has a rotor rigidly and coaxially connected to the needle cylinder, and a stator located adjacent to the rotor and supported by the main structure.

Abstract: The circular knitting machine for socks, stockings or the like, in particular for producing knitting with towelling stitches, comprises, at the set of knitting-forming cams which actuate the motion of the needles during the engagement of the thread or threads at one feed of the machine, an additional cam. The additional cam is arranged above the central cam and defines a descending portion which is engageable with the heel of the needles, excluded from knitting at that feed and raised with respect to the needles which knit at that feed. The controlled lowering of the needles which do not knit at the feed facilitates the positioning of the thread or threads fed at the feed and the correct forming of the loops by the needles which knit at that feed.

Abstract: The machine has a rotatable needle cylinder and a casting-off sinker actuation device including a coaxial sinker ring supporting a cam and an external countercam. The needle cylinder supports a plurality of casting-off sinkers each having a heel which follows a path, extending around the needle cylinder axis, which is partially defined by the cam and the countercam. A pin is connected to the countercam and is engaged by an actuation element associated with the sinker ring and bilaterally engaging the pin. The actuation element is controllably activatable for bilaterally moving the countercam with respect to the needle cylinder along a direction having a radial component, toward or away from the axis of the needle cylinder.

Abstract: The present machine has a device for repeating the selection of the needles at least at one thread feed, which includes a memory element arranged proximate to the lower end of the selectors, which can oscillate in a plane radial to the needle cylinder by virtue of the action of selection levers arranged upstream of a thread feed of the machine, according to the direction of the rotation imparted to the needle cylinder about its own axis. The selectors can individually oscillate in a radial plane with respect to the needle cylinder from an extraction position, whereat they protrude from the needle cylinder with a main heel so as to engage actuation cams arranged about the needle cylinder, to a sunk position, whereat they do not engage the cams.

Abstract: The process consists in producing a body of knitting having a substantially tubular extension, with portions which are to be removed and a remaining part. The remaining part is knitted with a plurality of threads. The portions which are to be removed are knitted with fewer threads than the remaining part.

Abstract: In the process a first thread differing in color with respect to a second thread which constitutes the stocking is fed by a thread guide alternatively to the second thread to a preset number of needles during the formation of a row of stitches. The first thread, which constitutes the design, is cut proximate to the ends of the portion of the row knit by the preset number of needles and the ends of the thread are moved towards the inside of the needle cylinders by means of a flow of air.

Abstract: The device has a box-like supporting structure which slidably accommodates at least one slider arranged laterally facing the needle cylinder of the machine and is movable, by virtue of the action of a linear motor, along a direction which is radial to the needle cylinder. The slider is rigidly associated, with its end which protrudes out of the box-like structure, with a knitting cam which is selectively engageable with needle actuation elements by moving the slider. The slider is constituted by a shaft which is slidably supported, along its axis, by the box-like structure by means of a first bearing which is arranged inside the box-like structure and has balls partially accommodated in longitudinal seats defined on the outer surface of the shaft and in seats correspondingly defined on the inner surface of a bush which extends around the shaft and is prevented from rotating about its axis.

Abstract: The device for locking selectors on the bottom of the needle cylinder grooves in circular knitting machines has a locking element which extends around the needle cylinder of the machine proximate to the lower end of the selectors, accommodated in the grooves of the needle cylinder. The locking element is controllably movable in a direction substantially parallel to the axis of the needle cylinder from an inoperative position, wherein the locking element is arranged substantially below the lower end of the selectors to allow the lower end of the selectors to perform an extraction movement from the related groove in a radial direction with respect to the needle cylinder, to an operative position, wherein at least one portion of the locking element is arranged above the lower end of the selectors for their retention in an inserted position in the related grooves, and vice versa.

Abstract: The device is provided with a plurality of selection levers pivotally connected to a support structure and having an end adjacent to the needle cylinder in the zone of the selectors. Actuators oscillate the selection levers in a plane parallel to the extension of the selectors, from an operative position, whereat the end is located at an intermediate level between the selector butts to avoid interference therewith, to an operative position whereat the end is located at the level of the selector butts to interfere therewith. Each selection lever has a first portion and a second portion which are spaced apart, extend parallel to the axis of their pin, and are connected together by cross-members defining a seat for the pin. The first portion has, at its intermediate part, a plate which extends in the direction of the selector butts, and which constitutes the end engageable therewith.

Abstract: The device comprises a plurality of superimposed selecting levers, individually pivoted in an intermediate portion thereof to a supporting structure and oscillatable in a plane substantially parallel to the extension of the plurality of selecting levers. The selecting levers are oscillatable from a first position, in which one of their ends is at a level which is intermediate between the heels of the selectors so as to avoid interfering therewith, to a second position, in which this end is at the level of the heels of the selectors, so as to interfere therewith and push the related selectors to an inoperative position. The other end of the selecting levers is shaped, at least for a portion, like a flat blade which extends in a plane substantially perpendicular to the extension of the plurality of selecting levers, the blade-like portion having its two opposite faces engaged with actuating levers for the oscillation of the selecting levers.

Abstract: The device comprises a plurality of superimposed selection levers, individually pivoted at an intermediate portion thereof to a supporting structure. The selection levers have an end facing the needle-bearing cylinder in the region of the selectors and are oscillable on a plane parallel to the extension of the plurality of selection levers to interfere or not interfere with the heels of the selectors. An actuating lever acts on the other end of each selection lever, is pivoted at an intermediate portion thereof to a frame, and can oscillate on a plane parallel to the plane of oscillation of the selection levers. For the oscillation of the actuating lever, two electromagnets, arranged on opposite sides with respect to the fulcrum of the actuating lever and alternately operable, are employed.

Abstract: The control device comprises a switching valve acting on the pneumatic circuit for passing from a first tensioning phase to a second transport phase and vice versa, and a step motor operated by an electronic machine control member and operatively connected to the cutoff element of the switching valve. The step motor allows to perform, according to a preset program, the passage from the first phase to the second phase and vice versa, and to achieve, at least in the first phase, a choking of the flow which crosses the switching valve to adjust the tension to which the product is subject.

Abstract: The machine comprises: a space defined between the needle cylinder and cylinder holder, and in communication with the delivery conduit of a feed pump, delivery ports defined on the needle cylinder for connecting the space to the outside, a collector pan located in the proximity of the needle cylinder base and supplying an oil collecting case in communication with the feed conduit of the cited pump. The delivery conduit is in communication with the cited space through the needle cylinder bearing and the oil collecting case houses the gear train for transmitting the rotary motion to the needle cylinder. The delivery ports are provided on the bottom of the needle cylinder flutes which accommodate the needles and jacks. Thus, thorough and continuous lubrication of the machine main members is achieved.

Abstract: The circular knitting machine has a protective screen in the processing area which comprises a containment body extending around and above the needle-bearing cylinder to define a chamber, containing the needle-bearing cylinder and being isolatable from the environment. The containment body has a lateral surface provided in at least two parts, of which at least one is movable with respect to the other for opening or closing said chamber; holes being also provided for the passage of the threads passing through the containment body for feeding the machine.

Abstract: The machine comprises a plurality of selectors which are slideably accommodated in the grooves of the lower needle-bearing cylinder and act each with its upper end on a transfer sinker, or slider, for moving the matching needle. The machine has the peculiarity that in a same groove of the lower needle-bearing cylinder is accommodated, proximate to the upper end of the selector, a pusher element, controllably engageable with the lower end of the matching transfer sinker. The pusher element has the possibility of being operated independently from the selector accommodted in the same groove, since it is provided with a heel which is engageable in suitably defined tracks on the skirt of the cams of the lower needle-bearing cylinder.