Circular knitting machine and a method for moving the needles of a circular knitting machine

Patent metadata

Field	Value
Publication number	US-11214899-B2
Application number	US-201816608052-A
Country	US
Kind code	B2
Filing date	Mar 27, 2018
Priority date	Apr 24, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A circular knitting machine includes a needle-holding cylinder having plurality of longitudinal grooves housing plurality of needles, at least one yarn feed operatively associated to needles, actuating cams arranged around and movable relative to cylinder, drive chain for each needle operatively placed between needle and actuating cams. Drive chain includes: sub-needle, selector having butt which can be engaged with selector paths, selecting device acting, punch equipped with butt which can be engaged with punch paths. Punch paths include a tuck stitch ascent and drop stitch ascent for each yarn feed. Inlet of drop stitch ascent circumferentially precedes inlet of tuck stitch ascent. Selector paths include a single track defining first and second ascents placed in succession for each yarn feed. First ascent circumferentially precedes second and is operatively associated to drop stitch ascent and second ascent is operatively associated to tuck stitch ascent.

First claim

The invention claimed is:

1. A circular knitting machine, comprising:
a needle-holding cylinder having a plurality of longitudinal grooves arranged around a central axis of the needle-holding cylinder;
a plurality of needles, each being housed in a respective longitudinal groove;
at least one yarn feed operatively associated to the needles;
actuating cams arranged around the needle-holding cylinder and movable with respect to said needle-holding cylinder around the central axis for causing or allowing the movement of the needles along the longitudinal grooves so as to enable stitch formation by said needles;
a drive chain for each needle inserted into the respective longitudinal groove, located below the respective needle and operatively placed between the respective needle and said actuating cams;

wherein said drive chain comprises:
a sub-needle arranged below the needle;
a selector arranged below the sub-needle having at least one respective butt radially movable between an operating position, in which it is extracted so as to engage with respective selector paths defined by selector cams, and a non-operating position, in which it is retracted so as not to engage with said selector paths;
at least one selecting device acting under control upon said selector for switching the latter into or retaining it in the operating position or the non-operating position;
a punch arranged between the sub-needle and the selector, wherein a lower portion of the punch is engaged with the selector and an upper portion of the punch is engaged with the sub-needle, wherein the punch has a respective butt which can be engaged with respective punch-paths defined by punch cams;
wherein, taking as reference the drive chain which is configured to rotate with respect to the actuating cams around the central axis in a sense of rotation, the punch-paths comprise a tuck stitch ascent and a drop stitch ascent for each yarn feed, and wherein an inlet of the drop stitch ascent is adapted to circumferentially precede an inlet of the tuck stitch ascent; wherein the selector paths comprise a single track defining a first ascent and a second ascent placed in succession one after the other for each yarn feed; wherein the first ascent is adapted to circumferentially precede the second ascent; wherein the first ascent is operatively associated to the drop stitch ascent and the second ascent is operatively associated to the tuck stitch ascent.

2. The machine according to claim 1 , wherein an inlet of the drop stitch ascent is adapted to immediately precede an inlet of the tuck stitch ascent.

3. The machine according to claim 1 , wherein the tuck stitch ascent and the drop stitch ascent merge one into the other after respective maximum height points.

4. The machine according to claim 1 , wherein the single track has at least one wavy segment with peaks and valleys, and wherein said wavy segment comprises the first ascent and the second ascent; wherein the wavy segment comprises a first descent, wherein the first descent connects the first ascent to the second ascent; wherein the wavy segment comprises a second descent following the second ascent; wherein inlet points of the butt of the selector in the wavy segment are defined on a base of the first ascent and on a base of the second ascent.

5. The machine according to claim 4 , wherein the single track has a disengaging area for each yarn feed; wherein the disengaging area follows the second descent and is configured for enabling the respective butt to radially get out from said single track.

6. The machine according to claim 5 , wherein said disengaging area has at least one outlet ramp extending between a bottom surface of the single track and a radially more external surface.

7. The machine according to claim 1 , wherein an axial extension of the first ascent is basically the same as an axial extension of the second ascent; wherein a circumferential extension of the first ascent is basically the same as a circumferential extension of the second ascent.

8. The machine according to claim 1 , wherein the first ascent is circumferentially offset in advance with respect to the respective drop stitch ascent, and the second ascent is circumferentially offset in advance with respect to the respective tuck stitch ascent.

9. The machine according to claim 1 , wherein a maximum height of the first ascent is adapted to circumferentially precede an inlet of the respective drop stitch ascent; wherein a base of the second ascent is adapted to circumferentially precede an inlet of the respective tuck stitch ascent; wherein a maximum height of the second ascent is adapted to circumferentially precede a maximum height of the respective tuck stitch ascent.

10. The machine according to claim 1 , wherein the yarn feed follows respective maximum height points of the tuck stitch ascent and of the drop stitch ascent.

11. The machine according to claim 1 , comprising at least two yarn feeds, wherein the single track comprises a disengaging area associated with each yarn feed and at least two wavy segments, each being placed between two disengaging areas one circumferentially after the other.

12. The machine according to claim 11 , wherein the disengaging area is symmetrical with respect to the respective yarn feed; wherein the wavy segment is symmetrical with respect to a middle axial straight line located in an intermediate position between two yarn feeds one circumferentially after the other; wherein the disengaging area has two outlet ramps placed on opposite ends thereof.

13. The machine according to claim 11 , wherein the wavy segment comprises a central protrusion symmetrical with respect to the middle axial straight line and two side protrusions; wherein a valley is defined between the central protrusion and two side protrusions.

14. The machine according to claim 11 , wherein the punch paths comprise a first pair of tuck stitch and drop stitch ascents and a second pair of tuck stitch and drop ascents coupled to each yarn feed and arranged symmetrically with respect to said yarn feed; wherein the tuck stitch and drop stitch ascents of the first and second pair merge into a central area of the punch paths aligned with the respective yarn feed.

15. The machine according to claim 1 , wherein said at least one selecting device comprises two actuators circumferentially placed one beside the other and located between two successive yarn feeds; wherein each of the actuators is placed on a respective valley defined by the wavy segment.

16. The machine according to claim 1 , wherein the actuator comprises a first array of levers and a second array of levers axially overlapping the first array of levers; wherein the first array of levers is configured for operating if the relative rotation of the needle-holding cylinder with respect to the actuating cams occurs in counterclockwise sense; wherein the second array of levers is configured for operating if the relative rotation of the needle-holding cylinder with respect to the actuating cams occurs in clockwise sense.

17. A method for moving the needles of a circular knitting machine, wherein said machine is in accordance with claim 1 , comprising the steps of:
causing a relative rotation between the needle-holding cylinder and the actuating cams;

wherein the following steps are provided for:
engaging the butt of the selector into a first inlet point defined on a base of the first ascent;
lifting the selector by means of said relative rotation and a subsequent sliding of the respective butt on the first ascent;
lifting the pun

Assignees

• Santoni & C Spa

Inventors

• Lonati Andrea
• Alghisi Mauro
• Lodrini Maurizio

Classifications

• D04B15/78

  Electrical devices · CPC title

• D04B9/20

  with provision for narrowing or widening; with reciprocatory action, e.g. for knitting of flat portions · CPC title

• D04B15/68

  characterised by the knitting instruments used · CPC title

• D04B15/32 Primary

  Cam systems or assemblies for operating knitting instruments · CPC title

• D04B9/02 Primary

  with one set of needles · CPC title