A shaped sinker for knitting machines, in particular for manufacturing open-work knitted fabrics

Abstract

A shaped sinker ( 1 ) for knitting machines includes a main horizontal body ( 2 ), destined to be slidingly housed inside a radial groove of a sinker-holding crown of a knitting machine and having a main longitudinal development between a rear portion ( 2 A) and a front portion ( 2 B); an upright ( 3 ) developing vertically from the main body near the front portion ( 2 B) and ending on top with an upper portion ( 4 ) defining an upper resting plane ( 30 ) destined to receive one or more yarns resting thereupon during stitch formation; and a protrusion ( 6 ) rising from the upper portion of the upright, developing towards the front portion of the main body and having on top a sliding plane ( 60 ). The protrusion rises from the upper portion of the upright so that the sliding plane is moved forward with respect to the upper resting plane of the upright. The protrusion is laterally offset or inclined with respect to the upright, from which it rises, and is configured for loading and stretching an interstitch and arrange it on an adjacent needle of the knitting machine so as to form an open work. The sliding plane of the protrusion is lowered with respect to the upper resting plane of the upright.

1 . A shaped sinker ( 1 ) for knitting machines, the shaped sinker being configured in particular for manufacturing open-work knitted fabrics and comprising:
 a main body ( 2 ) shaped like a horizontal flat bar and destined to be slidingly housed inside a radial groove ( 103 ) of a sinker-holding crown ( 102 ) of a knitting machine so as to move radially in a controlled manner inside the groove, the main body ( 2 ) having a main longitudinal development and extending between a rear portion ( 2 A) and a front portion ( 2 B);   an upright ( 3 ) shaped like a vertical flat element and developing vertically, i.e. rising, from said main body ( 2 ) near or at said front portion ( 2 B) or in an intermediate position between the rear portion ( 2 A) and the front portion ( 2 B), wherein said upright ( 3 ) ends on top with an upper portion ( 4 ) defining an upper resting plane ( 30 ) destined to receive one or more yarns resting thereupon during stitch formation;   wherein said main body ( 2 ) and said upright ( 3 ) preferably lie on one lying plane (G) of the shaped sinker ( 1 );   the shaped sinker ( 1 ) further comprising a protrusion ( 6 ) rising from said upper portion ( 4 ) of the upright ( 3 ) and developing on the upright side facing the front portion ( 2 B) of the main body ( 2 ),   wherein said protrusion ( 6 ) has on top a sliding plane ( 60 ), the protrusion ( 6 ) protruding from the upper portion ( 4 ) of the upright ( 3 ) so that the sliding plane ( 60 ) of the protrusion is moved forward with respect to the upper resting plane ( 30 ) of the upright ( 3 ), according to a direction pointing to the front end of the main body,   wherein said protrusion ( 6 ) is laterally offset or inclined with respect to the upright ( 3 ) of the shaped sinker ( 1 ), from it rises, the protrusion ( 6 ) being configured for loading and stretching an interstitch and arrange it on an adjacent needle of the knitting machine so as to form an open work, and   wherein said sliding plane ( 60 ) of the protrusion ( 6 ) is at least partially lowered with respect to the upper resting plane ( 30 ) of the upright ( 3 ), the sliding plane ( 60 ) of the protrusion being configured for receiving thereon one or more yarns when loading and stretching the interstitch during open work formation.   
     
     
         2 . The shaped sinker ( 1 ) according to  claim 1 , wherein the protrusion ( 6 ) is bent, inflected or curved laterally with respect to the upright ( 3 ), in particular with respect to the upper portion ( 4 ) of the upright ( 3 ), and/or wherein the protrusion ( 6 ) is offset or inclined laterally with respect to the upright ( 3 ) so as not to lie on said lying plane (G) of the shaped sinker, and/or wherein the protrusion ( 6 ) can be offset or inclined laterally, with respect to the upright, to the right or to the left with respect to the lying plane (G) of the shaped sinker. 
     
     
         3 . The shaped sinker ( 1 ) according to  claim 1 , wherein the sliding plane ( 60 ), lowered with respect to the upper resting plane ( 30 ) of the upright ( 3 ), develops in a continuous manner with respect to the upper resting plane ( 30 ), a connecting step ( 61 ) being present, downwards, in the transition from the upper resting plane to the sliding plane, and/or wherein said step ( 61 ) is rounded off or connected so that the passage from the upper resting plane ( 30 ) to the sliding plane ( 60 ) takes place without discontinuity between the surface of the upper resting surface ( 30 ) and the surface of the sliding plane ( 60 ), and/or wherein the resting plane ( 30 ) is a planar surface, i.e. lying on one, preferably horizontal plane, and the sliding plane ( 60 ) is a respective surface at least partially lowered downwards, i.e. towards the main body ( 2 ) of the shaped sinker. 
     
     
         4 . The shaped sinker ( 1 ) according to  claim 1 , wherein the protrusion ( 6 ) is configured so that, in use, the backward movement of the shaped sinker ( 1 ), carrying a yarn on the resting surface ( 30 ) of the upright, causes the passage of the yarn on the protrusion ( 6 ) which, being offset laterally, loads and stretches the interstitch so as to arrange it on an adjacent needle, wherein the sliding plane ( 60 ), lowered with respect to the upper resting plane ( 30 ), is configured for counterbalancing/containing the increase in tension on the yarn caused by the stretching introduced by the lateral offset of the protrusion ( 6 ), so as to maintain a correct and/or constant tension of the interstitch when forming the open work, and/or wherein the structure, e.g. the respective shape or vertical height, of the resting plane ( 30 ) and the sliding plane ( 60 ) is configured for counterbalancing the stretching caused by the lateral offset of the protrusion ( 6 ), so as to maintain a correct length of the interstitch when forming the open work, and/or wherein the sliding plane ( 60 ) lowered with respect to the upper resting plane ( 30 ) is configured for reducing the tension and/or pressure exerted by the interstitch, during loading, on the protrusion ( 6 ). 
     
     
         5 . The shaped sinker ( 1 ) according to  claim 1 , wherein the protrusion ( 6 ) has a base ( 62 ), connected to the front side ( 3 A) of the upper portion ( 4 ) of the upright ( 3 ), from which the protrusion itself develops and protrudes as far as an end tip ( 63 ) of the protrusion, opposed to said base ( 62 ), and/or wherein the sliding plane ( 60 ) of the protrusion, lowered with respect to the upper resting plane ( 30 ) of the upright, is made like an inclined plane ( 64 ) downwards, developing in a continuous manner from the base ( 62 ) of the protrusion to the end tip ( 63 ), and/or wherein the inclination of the sliding plane ( 60 ) of the protrusion ( 6 ) increases from the base ( 62 ) to the end tip ( 63 ), so that the lowering of the sliding plane ( 60 ), with respect to the resting plane ( 30 ), is greater towards the end tip. 
     
     
         6 . The shaped sinker ( 1 ) according to  claim 1 , wherein the lateral offset of the protrusion ( 6 ) with respect to the lying plane (G) of the shaped sinker increases from the base ( 62 ) to the end tip of the protrusion ( 63 ), i.e. the protrusion ( 6 ) gets progressively away along the protrusion itself, from the base ( 62 ) to the end tip ( 63 ), and/or wherein, the protrusion ( 6 ) being bent with respect to the lying plane (G) so as to get progressively away from the lying plane itself towards the end tip ( 63 ), the stretching of the interstitch placed on the sliding plane ( 60 ) increases progressively as the shaped sinker moves backward, the tension on the yarn increasing at the same time when loading it onto the protrusion, and the downward inclination of the sliding plane ( 60 ) is configured for retrieving and counterbalancing gradually the progressive increase in tension on the yarn caused by the stretching introduced by the lateral offset of the protrusion ( 6 ), so as to maintain a correct and/or constant tension of the interstitch while forming the open work, and/or as the protrusion ( 6 ), with the shaped sinker moving backward, widens the interstitch and increases progressively the tension on the yarn, the inclined plane ( 64 ) of the protrusion counterbalances the increase in tension that would be introduced without a lowering or an inclination of the sliding plane of the protrusion ( 6 ), and/or wherein the end tip ( 63 ) comprises a stopping portion ( 65 ), raised with respect to a lower end of the sliding plane ( 60 ), and wherein the stopping portion ( 65 ) represents an abutment at the end of the sliding plane, configured for stopping the sliding of the yarn at the end of the protrusion ( 6 ) and retaining the yarn and preventing it from detaching from the sliding plane ( 60 ) and separating from the protrusion. 
     
     
         7 . The shaped sinker ( 1 ) according to  claim 1 , comprising a fin ( 70 ) placed behind the upper portion ( 4 ) of the upright ( 3 ), i.e. on the upright side opposed to the side from which the protrusion develops, wherein the fin ( 70 ) has on top a supporting plane ( 71 ), and/or wherein the fin ( 70 ) can be positioned so that its supporting plane ( 71 ) is moved backward with respect to the upper resting plane ( 30 ) of the upright ( 3 ), according to a direction towards the rear end ( 2 A) of the main body ( 2 ). 
     
     
         8 . The shaped sinker ( 1 ) according to  claim 1 , wherein the fin ( 70 ) rises from the upper portion ( 4 ) of the upright ( 3 ) and develops from the upright side facing the rear portion of the main body, and/or wherein the fin ( 70 ) develops from the rear side ( 3 B) of the upright, opposed to the front side ( 3 A) from which the protrusion ( 6 ) develops, and/or wherein the fin ( 70 ) protrudes on the back from the upper portion ( 4 ) of the upright ( 3 ) so that said supporting plane ( 71 ) is moved backward with respect to the upper resting plane ( 30 ) of the upright ( 3 ), according to a direction towards the rear end ( 2 A) of the main body ( 2 ), and/or wherein the fin ( 70 ) protrudes on the back from the upright ( 3 ) so that the supporting plane ( 71 ) of the fin develops in a continuous manner from the resting plane ( 30 ) of the upright, and/or wherein the supporting plane ( 71 ) of the fin ( 70 ) and the resting plane ( 30 ) of the upright ( 3 ) are coplanar and have the same vertical height. 
     
     
         9 . The shaped sinker ( 1 ) according to  claim 1 , wherein:
 during a knitting operation combining an open work with the use of at least one yarn having at least one low trajectory portion, i.e. passing at a lower height that the height of the resting plane ( 30 ) of the upright ( 3 );   for making the open work the shaped sinker, in order to transfer the interstitch to one of the adjacent needles, has to perform a backward motion during which the rear side ( 3 B) of the upright ( 3 ) might push, deviate or interfere with the yarn having said at least one low trajectory portion;   the fin ( 70 ) is configured for supporting, by means of said supporting plane ( 71 ), said at least one yarn having said at least one low trajectory portion, by letting said trajectory pass above the supporting plane of the fin and preventing the rear side of the upright from pushing or interfering with said at least one yarn during the backward shifting movement of the shaped sinker, and/or wherein the yarn having at least one low trajectory portion is a yarn fed below a yarn guiding element, typically, a “box”, and/or wherein said yarn having at least one low trajectory portion is a yarn design to take part in a plated design, and/or wherein the fin ( 70 ) is configured for working, supporting a yarn by means of said supporting plane ( 71 ), when the shaped sinker ( 1 ) makes an open works and at the same time adjacent needles make plain or terrycloth knitted structures.   
     
     
         10 . The shaped sinker ( 1 ) according to  claim 1 , wherein the supporting plane ( 71 ) of the fin ( 70 ) and the resting plane ( 30 ) of the upright ( 3 ) are both horizontal surfaces, preferably parallel to the underlying main body of the shaped sinker, and/or wherein the supporting plane ( 71 ) of the fin ( 70 ) is not lowered with respect to the resting plane ( 30 ) of the upright ( 3 ), and/or wherein the supporting plane ( 71 ) of the fin and the resting plane ( 30 ) of the upright are aligned along a longitudinal direction, i.e. the fin ( 70 ) is coplanar with the upright ( 3 ) and lies on said lying plane (G) of the shaped sinker, or wherein the fin ( 70 ) is offset or inclined laterally with respect to the upright ( 3 ), from it rises, so as not to lie on said lying plane (G) of the shaped sinker ( 1 ), and/or wherein the lateral offset of the fin ( 70 ) is configured for avoiding interferences with a further sinker placed laterally, and/or wherein the fin ( 70 ) is offset or inclined laterally, with respect to the upright ( 3 ), in the same offset direction of the protrusion ( 6 ). 
     
     
         11 . The shaped sinker ( 1 ) according to  claim 1 , wherein the main body ( 2 ), the upright ( 3 ) and the protrusion ( 6 ) are made as one piece, thus forming a single-piece shaped sinker, and/or wherein the fin ( 70 ) is made as one piece with said upright ( 3 ), or wherein the fin ( 70 ) is a distinct element from the upright ( 3 ), placed behind the upper portion of the upright, so that the supporting plane of the fin is moved backward and aligned with respect to the upper plane of the upright, and/or wherein the shaped sinker ( 1 ) is completely made as one piece, and/or wherein the shaped sinker ( 1 ) has in all its part a basically constant thickness. 
     
     
         12 . An assembly (A; B) of flat parts of a circular knitting machine, the assembly comprising:
 a knockover sinker ( 7 ) or an interstitch-knockover sinker ( 7 ′) , provided with a pin ( 13 ,  13 ′) configured for cooperating with the needles (N) of a knitting machine and with a butt ( 14 ,  14 ′) destined to cooperate with suitable driving means of the knitting machine so as to cause a shifting movement of the knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), in radial direction with respect to a central axis (X) of the knitting machine;   at least one shaped sinker ( 1 ) according to  claim 1 , the shaped sinker ( 1 ) being movable with respect to the knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′);   wherein the assembly (A; B) is configured for being housed in a respective radial groove ( 103 ) of a crown ( 102 ) arranged around a needle-holding cylinder ( 101 ) of the knitting machine, so that said at least one shaped sinker ( 1 ) lies beside said knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), said at least one shaped sinker ( 1 ) and said knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′) being movable radially, in an independent manner, in the respective radial groove ( 103 ).   
     
     
         13 . The assembly according to  claim 12 , comprising a group of flat metal parts destined to slide radially in a respective radial groove ( 103 ) and one with respect to the other, too, the assembly comprising an interstitch-knockover sinker ( 7 ′), a right shaped sinker ( 8 ) and a left shaped sinker ( 9 );
 wherein the interstitch-knockover sinker ( 7 ′) comprises a respective main body shaped like a horizontal flat bar ( 12 ′) oriented as the groove ( 103 ), and a vertical flat upright ( 50 ) developing from the horizontal flat bar ( 12 ′), the interstitch-knockover sinker ( 7 ′) further comprising a vertical tooth ( 51 ) developing above said upright ( 50 ), 
 wherein the tooth ( 51 ) has a front surface ( 52 ) configured for retaining, or “knocking over”, the interstitch loaded and stretched by the protrusions ( 6 ) of the right shaped sinker ( 8 ) and of the left shaped sinker ( 9 ), 
 and/or wherein the tooth ( 51 ) is configured for retaining, by means of the front surface ( 52 ), the interstitch carried by the protrusions of the right shaped sinker ( 8 ) and of the left shaped sinker ( 9 ) during their backward motion made so as to place the interstitch one or more adjacent needles so as to form an open work, and/or wherein the front surface ( 52 ) of the tooth ( 51 ) is configured from preventing, during the backward motion of the right and left shaped sinker so as to form an open work, the interstitch from being drawn radially backwards, and/or wherein the front surface ( 52 ) of the tooth ( 51 ) is configured for pushing forward the interstitch on the protrusions ( 6 ), during the backward motion of the right ( 8 ) and left ( 9 ) shaped sinkers so as to form an open work, so that the interstitch is spread at its maximum on the protrusions themselves. 
 
     
     
         14 . A circular knitting machine for manufacturing open-work knitted fabric, comprising:
 a needle-holding cylinder ( 101 ) having a plurality of longitudinal grooves arranged around a central axis (X) of the needle-holding cylinder ( 101 );   a plurality of needles (N), each being housed in a respective longitudinal groove;   at least one yarn feed operatively associated to the needles (N);   a crown ( 102 ) arranged around the needle-holding cylinder ( 101 ) and having a plurality of radial grooves ( 103 );   at least one guiding ring ( 90 ) operatively associated to the crown ( 102 ), wherein the crown ( 102 ) is rotatable with respect to the guiding ring ( 90 ) and around the central axis (X);   a plurality of knockover sinkers ( 7 ) and/or of interstitch-knockover sinkers ( 7 ′), each housed in one of the radial grooves ( 103 ) and radially movable in the respective radial groove ( 103 ), each knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′) having a pin ( 13 ,  13 ′) configured for cooperating with the needles (N) and a butt ( 14 ,  14 ′) engaged with a first guide ( 91 ) obtained in the guiding ring ( 90 ) and developing around the central axis (X); wherein the first guide ( 91 ) is configured for moving the knockover sinker ( 7 ) or the interstitch-knockover sinker ( 7 ′) radially along the respective radial groove ( 103 ) when the crown ( 102 ) rotates with respect to the guiding ring ( 91 ) and around the central axis (X);   wherein the machine comprises at least one shaped sinker ( 1 ) according to  claim 1 , beside a respective knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), wherein the shaped sinker ( 1 ) is movable with respect to the knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′).   
     
     
         15 . The knitting machine according to  claim 14 , wherein said at least one shaped sinker ( 1 ) comprises a right shaped sinker ( 8 ) and a left shaped sinker ( 9 ) arranged on opposed sides of the respective knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), and wherein:
 the right shaped sinker ( 8 ) has its protrusion offset laterally to the right with respect to the respective upright; 
 the left shaped sinker ( 9 ) has its protrusion offset laterally to left the with respect to the respective upright; 
 and/or wherein the right shaped sinker ( 8 ) and the left shaped sinker ( 9 ) have their protrusions offset laterally to opposed sides of said knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′) and preferably located above the respective knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), and/or wherein the protrusions ( 6 ) are configured for loading and stretching the interstitch and arrange it on two adjacent needles placed on opposed sides of the respective knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′) and form the open work, 
 and/or wherein said at least one shaped sinker ( 1 ) is housed in one of the radial grooves ( 103 ) together with the respective knockover sinker ( 7 ) or interstitch-knockover sinker ( 7 ′), and/or wherein one of the radial grooves ( 103 ) houses: 
 a first assembly (A) made up of the knockover sinker ( 7 ) and of the shaped sinker ( 1 ), or right shaped sinker ( 8 ) and left shaped sinker ( 9 ); or 
 a second assembly (B) made up of the interstitch-knockover sinker ( 7 ′) and of the shaped sinker ( 1 ), or right shaped sinker ( 8 ) and left shaped sinker ( 9 ).