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 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 knitting machine has a device for raising and lowering the platen, which comprises a frame, associated with the supporting structure of the machine, which supports the platen above the needle-bearing cylinder. The machine also comprises at least one guiding column for sliding said frame with respect to the supporting structure of the machine along a direction parallel to the axis of the needle-bearing cylinder and a step motor which is connected to an electronic member for controlling the machine and which acts on moving means connected to said frame and to the supporting structure to perform the above described sliding according to a preset program.

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.

Abstract: The device includes a slide movable in a substantially perpendicular direction to the axis of the needle cylinder and being rigidly associated with a knitting cam selectively engageable with the needle butts, and a step motor actuated by an electronic machine control. The step motor is connected to a drive cam which engages with a cam follower carried on the cited slide to produce a preset displacement of the knitting cam with respect to the needle cylinder on account of the knitting cam engaging selectively the needle butts.

Abstract: For controlling selection of needles, intermediate jacks or pattern jacks in a circular knitting machine there is provided a stepwise advanced pattern drum selectively acting on selection slides which interfere with butts of needles, intermediate jacks or pattern jacks. The drum is advanced by a pawl pivoted to a rocking lever controlled by a cam profile the axis whereof is different from the axis of the needle cylinder. The cam is rotated at a speed timed to that of the needle cylinder. The cam has two different profiles at different heights for acting on the lever and may be provided with additional superposed profiles for direct action on the selection slides.

Abstract: For adjusting loop density in a circular knitting machine there is provided a step motor arranged below the needle cylinder and having a threaded shaft threadably engaging one end of a lever pivoted to a stationary structure of the machine. The free end of the threaded shaft abuts against a rotatable stop supported by the stationary portion of the machine, and the housing of the motor is prevented from rotating with respect to the lever. The opposed end of this lever supports a cylinder holder. Rotation of the threaded shaft of the step motor which is controlled by a programming member causes a pivotal movement of the lever and thus a raising or lowering movement of the needle cylinder to vary the loop density.

Abstract: A single or double cylinder circular knitting machine is adapted to effect renewal of a needle selection at one or more successive yarn feeds without requiring a respective pattern selection device therefor. The pattern jacks which have been selected, by a preceding pattern selection device, not to bring their respective needles to knit are moved radially inwards by a guiding cam, and are held separated from the other jacks even after the latter have brought their respective needles to knit. The cam may have a first movable part and a second fixed part. At one position of the movable part, the inoperative jacks are moved radially to the inside of the fixed part, and at the second position thereof, radially to the outside thereof, thereby they are restored to the selection position. This allows operation with a programmed selection even where the selection was formerly just reiterated.

Abstract: A knitwork drawing device which has a hollow piston rod movable axially through one of the needle cylinders in a double cylinder circular knitting machine, and a knitwork retaining member arranged at the height of the stitch-formation area and rotatable with the needle cylinders. The hollow piston rod is secured to a fluid-operated piston slidable in a cylindrical chamber coaxial with the needle cylinders. Tensioning of the knitwork is effected by leaving the hollow piston rod to rest on the knitwork being knitted, which is held at its initial portion by the retaining member internally of the hollow piston rod and by the needles which continue to knit externally of the hollow piston rod. The whole stroke of the piston and hollow piston rod is thus the half of the whole length of the knitwork and the axial dimension of the knitting machine is considerably reduced.

Abstract: For needle selection in a circular knitting machine, a device is disclosed which comprises a plurality of superimposed selecting levers, individually pivoted to a common structure and selectively movable between a position where they do not interfere with the pattern jack butts and a position where they interfere therewith, to urge them toward the needle cylinder. The selective movement is accomplished by means of electromagnets, one for each selecting lever, which are energized in accordance with the machine knitting program and move intermediate, preferably rod-like, drive elements the axial displacement whereof results in a pivotal movement of the respective selecting levers between the cited positions. The engagement of the intermediate elements with the selecting levers is accomplished through geometrical coupling. A minimal force is sufficient for the actuation, so that the size of the electromagnets can be minimized, while a prompt response is ensured.

Abstract: A circular knitting machine, in particular for knitting hosiery, is disclosed, wherein the dial is rotated by the needle cylinder through a rod extending coaxially with the cylinder and dial and rotatively connected to the latter. The rod can be shifted axially from a position of engagement with a drive element rigid with the cylinder, to a position of disengagement therefrom, and viceversa. In the former condition, the dial will be rotated in timed relationship with the cylinder, whereby the fabric is knitted normally, whereas in the latter condition, the knitted fabric is discharged. The rod axial movement may be obtained by pneumatically or hydraulically operated cylinder, whose piston is rotatably connected to the rod itself. It is further possible to make the dial raisable vertically through a pneumatic or hydraulic cylinder, such as to make the loop formation area fully accessible.

Abstract: A knitwork drawing device which has a hollow piston rod movable axially through one of the needle cylinders in a double cylinder circular knitting machine, and a knitwork retaining member arranged at the height of the stitch-formation area and rotatable with the needle cylinders. The hollow piston rod is secured to a fluid-operated piston slidable in a cylindrical chamber coaxial with the needle cylinders. Tensioning of the knitwork is effected by leaving the hollow piston rod to rest on the knitwork being knitted, which is held at its initial portion by the retaining member internally of the hollow piston rod and by the needles which continue to knit externally of the hollow piston rod. The whole stroke of the piston and hollow piston rod is thus the half of the whole length of the knitwork and the axial dimension of the knitting machine is considerably reduced.