Circular machine

Abstract

A circular double-cylinder hosiery knitting machine (1) comprising a lower needle cylinder (51) and an upper needle cylinder (52), which are mutually coaxial and can be actuated integrally with each other with a rotary motion about the common axis (100), said lower needle cylinder (51) and said upper needle cylinder (52) forming a respective lower skirt (51a) and upper skirt (52a) which have a plurality of axial grooves that can be engaged slidingly by a catenary-type movement assembly (10) and by a needle (11) provided with two heads, an upper head (11a) and a lower head (11b) respectively, a yarn feeding and cutting assembly being provided which comprises at least one first yarn finger (3) associated with a respective yarn cutting element (5) to provide a respective yarn tail (6), said circular machine (1) comprising at least one pusher element (7) configured for the insertion of said yarn tails (6) within the tubular manufacture being provided, a first drop and at least one second drop (8, 9) being provided which are positioned around the circumference of the needle cylinders (51, 52), said catenary-type movement assembly (10) being functionally associated with a cam assembly (20) extending around the axis of the cylinders (100) in order to actuate the movement of the needles (11) between a floating position, a tuck stitch position and a drop stitch position; the cam assembly (20) forms, between a first angular position (α), at which, substantially at a drop (9), a yarn tail (6) is provided, and a second angular position (β), which is arranged upstream of the following drop (8) along the knitting forming direction, a lowered path (30) which can be selected on command and can be engaged by the catenary-type movement assembly (10), the lowered path (30) comprising a first path portion (31) at which the catenary-type movement assembly (10) holds the respective needles (11) below the sinker elevation (200) or above the sinker tooth elevation (201) so as to allow the insertion of the yarn tail by said pusher element (7) within the tubular manufacture, and a second path portion to bring the needles (11) to the tuck stitch position.

Description

[0001] CIRCULAR MACHINE

[0002] The present invention relates to a circular hosiery knitting machine, in particular a circular double-cylinder machine.

[0003] As is known, circular double-cylinder hosiery knitting machines generally comprise a lower needle cylinder and an upper needle cylinder, which are mutually coaxial and can be actuated integrally with each other with a rotary motion around the common axis.

[0004] Each cylinder forms a plurality of radial millings or grooves which are identical to the other cylinder; in particular, the millings of the upper cylinder are perfectly opposite the millings of the lower cylinder.

[0005] A respective needle can slide in the grooves of the cylinders and its movement is actuated by two transfer sliders: in particular, for the movement of each needle there is a first slider accommodated in a groove of the lower cylinder and a respective slider accommodated in the corresponding groove of the upper cylinder.

[0006] Each slider has at least one heel that contributes to the ascent and descent of the respective needle. In the specific case, each slider is connected to a sub-needle (commonly termed oscillating jack), also provided with at least one heel, which can be made to knit by means of a sub-needle (or selector jack) that can be actuated by levers positioned radially to the respective cylinder.

[0007] In the lower cylinder, between two needles there is a knockover sinker, while in the upper cylinder there is a knockover tooth.

[0008] The two cylinders of the machine are surrounded by a skirt that carries the cams that act on the heels of the sliders and of the oscillating jacks to guide the needles into the transfer, lock, tuck stitch and drop stitch channels.

[0009] For this reason, in the 360° extension of the skirt cams there are regions that affect the forming of the knitting (usually a region for each drop or feed) and regions where the needle is transferred from one cylinder to the other.

[0010] The needles usually used on these machines are double-headed, or double-beaked with a latch (or double-hooked). Between the upper and lower heads there are two bumps that do not contribute to the ascending and descending movements of the needles.

[0011] The ascending and descending movements of the needle are obtained by virtue of the engagement between the head and the lug of the slider.

[0012] If the needle is engaged with the upper slider, it can produce purl knitting stitches, while if it is engaged with the lower slider it can produce plain knitting stitches.

[0013] In particular, when the needle is moved into the upper needle cylinder it knits with its lower head, while when it is moved into the lower needle cylinder it knits with its upper head.

[0014] The axial movement of the needle, generated by the rotation of the cylinders and by the engagement of the heels of the slider and of the oscillating jack on the cams of the skirt, entails that said needle must pass from one cylinder to the other, obstructing the free space that usually exists between the upper part of the knockover sinker and the lower part of the knockover tooth.

[0015] This interference prevents the knitting input or output tails from being pushed inside the tubular knitted manufacture during construction.

[0016] The operation of inserting the tails inside the tubular manufacture is even more difficult in machines with multiple drops, for example with two or three drops, wherein the spaces identified for inserting the tails inside the tubular manufacture are further reduced.

[0017] The angular reduction of the extension of the drops or the transfer region in order to recover space for inserting the tails would entail modifying the inclination of the sliding surfaces of the flat parts, compromising the machine's performance.

[0018] In fact, to avoid excessive stresses on the flat parts (i.e. the jacks and sliders), it is not possible to tilt excessively the sliding surfaces of the cams and consequently the space available to insert the tails inwards on the second drop is reduced with respect to that available for the first drop.

[0019] One of the solutions commonly used to solve this problem is to move the needles in the float channel so as to create a sufficiently large space that allows to move the cut tails towards the inside of the cylinders.

[0020] However, this solution is not always feasible, since it alters the design of the hosiery item, in particular when working in Jacquard knitting. This is mainly due to the fact that the needles that remain in the floated condition after the second drop cannot “pick up” the color dispensed in the first drop.

[0021] Moreover, in passing through the float channel of the first drop to create the space necessary for inserting the yam tails, a yarn bridge is created which is as long as the number of needles floating along the primary drop.

[0022] The aim of the present invention is to provide a hosiery knitting machine that is able to improve the background art in one or more of the aspects indicated above.

[0023] Within this aim, an object of the invention is to provide a hosiery knitting machine that can facilitate the insertion of the yarn tails inside the cylinders.

[0024] A further object of the invention is to provide a hosiery knitting machine capable of handling the steps of inserting the tails into the cylinders in an extremely flexible way without modifying the structure of the machine and the various control apparatuses.

[0025] Not least object of the invention is to provide a hosiery knitting machine that is highly reliable, relatively easy to provide and at competitive costs.

[0026] This aim, as well as these and other objects which will become more apparent hereinafter, are achieved by a hosiery knitting machine according to claim 1, optionally provided with one or more of the characteristics of the dependent claims.

[0027] Further characteristics and advantages of the invention will become more apparent from the description of a preferred but not exclusive embodiment of the hosiery knitting machine according to the invention, illustrated by way of nonlimiting example in the accompanying drawings, wherein:

[0028] Figure 1 is a schematic top view of a machine according to the invention;

[0029] Figure 2 is a flat projection view of the cam skirt that actuates the selector assembly, with the heel paths marked during knitting with floated and dropped stitches;

[0030] Figure 3 is an enlarged- scale view of a portion of the flat projection of the skirt of Figure 2;

[0031] Figure 4 is a sectional view, taken along a diametrical plane, of the cylinders of the circular machine according to the invention.

[0032] With reference to the figures, the circular double-cylinder hosiery knitting machine according to the invention, generally designated by the reference numeral 1, comprises a machine for the provision of a tubular manufacture comprising a lower needle cylinder 51 and an upper needle cylinder 52, which are mutually coaxial and can be actuated integrally with each other with a rotary motion around the common axis, designated by the reference numeral 100.

[0033] The lower needle cylinder 51 and the upper needle cylinder 52 form a respective lower skirt 51a and upper skirt 52a which have a plurality of axial grooves that can be engaged slidingly by a selection assembly 10 and by a needle 11 equipped with two heads, respectively an upper head I la and a lower head 11b.

[0034] Depending on whether it is desired to provide plain knitting stitches or purl knitting stitches, the needle 11 is translated into the upper needle cylinder 52 so that it knits with its lower head 11b, or into the lower needle cylinder 51 so that it knits with its upper head I la.

[0035] The needle 11, having no heel, is actuated by means of sliders 13 placed in the upper needle cylinder 52 and in the lower needle cylinder 51 depending on whether it must form plain stitches or purl stitches.

[0036] The circular machine 1 moreover has a yam feeding and cutting assembly 3 which comprises at least one first yam finger 4 associated with a respective element 5 for cutting the yam to create a respective yarn tail 6.

[0037] The at least one first yam finger 4 is movable on command, between a yarn finger inserted position and a yarn finger extracted position.

[0038] The circular machine 1 comprises at least one pusher element 7 configured for the insertion of the yarn tails 6 inside the tubular manufacture being provided.

[0039] According to the present invention, the feeding and cutting assembly 3 comprises a first drop 8 and at least one second drop 9, which are positioned around the circumference of the needle cylinders.

[0040] The first drop or feed 8 is typically the primary drop and is usually equipped with five or more yam fingers 4. For this reason, the space occupied by the first drop is greater than the space occupied by the other drops.

[0041] The second drop or feed 9 is usually equipped with two or three yarn fingers 4 and precedes, i.e., is arranged upstream along the direction of rotation of the cylinders 51 and 52, the transfer region of the needles 11.

[0042] This drop tends to take up less space because it is less important than the primary drop 8 and houses fewer yam fingers 4.

[0043] The needles 11 are moved by means of the action of a catenary-type movement assembly 10 which comprises the sliders 13; the catenary-type movement assembly 10 is functionally associated with a cam assembly 20 extending around the axis of the cylinders 100 to actuate the movement of the needles 11 between a float position, a tuck stitch position, and a dropped position. In particular, the catenary-type movement assembly 10 comprises, for each cylinder, the lower one 51 and the upper one 52, in addition to the sliders 13 that engage with the needle 11, an oscillating jack 12 and a selector jack 14.

[0044] According to the present invention, the cam assembly 20 defines, between a first angular position (designated by the letter a), in which, substantially at a drop, in particular the second drop 9, the yam tail 6 is provided, and a second angular position (designated by the letter 0) arranged upstream of the next drop, in particular upstream of the primary drop 8, according to the knitting forming direction, a lowered path 30 that can be selected on command and engaged by the catenary-type movement assembly 10.

[0045] The lowered path 30 is located immediately downstream of the stitch cam 9 a of the second drop 9.

[0046] In particular, the lowered path 30 comprises a first path portion 31 at which the catenary-type movement assembly 10 keeps the respective needles 11 below the sinker height, indicated with 200, if the needle 10 is located at the lower cylinder 51 , or above the height of the knockover tooth, indicated by 201, if the needle is arranged in the upper needle cylinder 52, so as to allow the insertion of the yam tail 6 by the pusher element 7 inside the tubular manufacture, and a second path portion 32 to bring the needles 11 into the tuck stitch position.

[0047] In fact, between the sinker elevation 200 and the sinker tooth elevation 201 there is an insertion portion, configured, among other things, to allow the pusher element 7 to act on the tails 6, when the needle 11 is in the floating position.

[0048] Advantageously, the cam assembly 20 comprises, at the skirt of the lower 51 and upper 52 cylinders, at least one band of skirt cams 21 that can be engaged by the respective slider 13 associated with the needle 11.

[0049] The at least one band of skirt cams 21, which can be engaged slidingly by the sliders 13, forms, between the first angular position a and the second angular position 0, at least one channel 33 for connection between the first path portion 31 , arranged below the at least one skirt cam band 21, and the second path portion 32, arranged above the at least one skirt cam band 21.

[0050] Spaced from the skirt cam band 21, in a downward region in the case of the lower cylinder 51 and in an upward region in the case of the upper cylinder 52, there is an engagement cam 22 configured to actuate the oscillating jacks 12 and therefore to actuate the respective sliders 13.

[0051] In particular, at the engagement cam 22 there is a control cam 40, in order to act on the oscillating jacks 12 so as to move the respective slider 13 from the first path portion 31 to the second path portion 32 through the connecting channel 33.

[0052] Advantageously, the first path portion 31 extends, at the lower cylinder 51, at a height greater than or equal to the knockover elevation.

[0053] Conveniently, the control cam 40 comprises a fixed cam, but nothing prevents the control cam 40 from being constituted by a movable cam.

[0054] According to a preferred practical embodiment, the circular machine 1 comprises a command and control device for the movement of the needles 11.

[0055] According to a particularly important aspect of the present invention, the command and control device comprises a links pattern actuator; said links pattern actuator is configured to actuate the oscillating jack 12 on the profile of the cam 40.

[0056] Of course, it is possible to provide for the actuation of the control cam 40 to be performed by an actuator that is dedicated to it.

[0057] Conveniently, the pusher element 7 comprises a device for emitting a jet of air 7a or a bristle brush device.

[0058] The pusher element 7 is arranged along the circumference of the cylinders between the first angular position and the second angular position. According to a preferred embodiment, the lowered path 30 can be provided at one of the cylinders 51 or 52 or at both cylinders 51 and 52.

[0059] Preferably, the lowered path 30 is provided at the lower cylinder 51 since generally it is necessary to provide for the insertion of the tails 6 inside the tubular element being provided.

[0060] However, in certain applications, for example in the case of the production of socks that are worn with turned-down cuffs, it is possible to provide the lowered path 30 at the upper cylinder 52.

[0061] The operation of the circular machine 1 , according to the invention, is substantially similar to the operation of a classic double-cylinder machine.

[0062] When, according to the “design” of the hosiery item being manufactured, a yam change or color change is required, for example at the second drop 9, the command and control device actuates the sliders 13 so that, upstream of the cutting element 5, they engage slidingly in the lowered path 30 and in particular along the first path portion 31 to keep the respective needle 11 in the floating position. In this way, the insertion space, formed between the sinker elevation 200 and the sinker tooth elevation 201, is not occupied by the needle 10 and therefore the pusher element 7 can easily act on the yam tail 6 cut by the cutting element 5.

[0063] By virtue of the action of the control cam 40, the oscillating jack 12, in a position that is upstream with respect to the region affected by the subsequent drop in the advancement direction (in this case with respect to the first drop 8), causes the passage of the respective slider 13 through the connecting channel 33 so as to bring the needle 11 to the tuck stitch position.

[0064] The solution devised allows, in particular, to increase the space available to insert the yam tails 6, without however altering the design of the Jacquard knitting.

[0065] In practice it has been found that the invention achieves the intended aim and objects, providing a double-cylinder circular machine provided with a selection assembly capable of facilitating the insertion of the yam tails inside the tubular manufactures being provided.

[0066] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

[0067] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art. The disclosures in Italian Patent Application No. 102024000014293 from which this application claims priority are incorporated herein by reference.

[0068] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. A circular double- cylinder hosiery knitting machine (1) for the provision of a tubular manufacture comprising a lower needle cylinder (51) and an upper needle cylinder (52), which are mutually coaxial and can be actuated integrally with each other with a rotary motion about the common axis (100), said lower needle cylinder (51) and said upper needle cylinder (52) forming a respective lower skirt (51a) and upper skirt (52a) which have a plurality of axial grooves that can be engaged slidingly by a catenary-type movement assembly (10) and by a needle (11) provided with two heads, an upper head (I la) and a lower head (11b) respectively, a yam feeding and cutting assembly being provided which comprises at least one first yarn finger (3) associated with a respective yam cutting element (5) to provide a respective yam tail (6), said at least one first yarn finger (3) being movable on command between an inserted yam finger position and an extracted yarn finger position, said circular machine (1) comprising at least one pusher element (7) configured for the insertion of said yam tails (6) within the tubular manufacture being provided, a first drop and at least one second drop (8, 9) being provided which are positioned around the circumference of the needle cylinders (51, 52), said catenary-type movement assembly (10) being functionally associated with a cam assembly (20) extending around the axis of the cylinders (100) in order to actuate the movement of the needles (11) between a floating position, a tuck stitch position and a drop stitch position, characterized in that said cam assembly (20) forms, between a first angular position (a), at which, substantially at a drop (9), a yarn tail (6) is provided, and a second angular position (0), which is arranged upstream of the following drop (8) along the knitting forming direction, a lowered path (30) which can be selected on command and can be engaged by said catenary-type movement assembly (10), said lowered path (30) comprising a first path portion (31) at which said catenary -type movement assembly (10) holds the respective needles (11) below the sinker elevation(200) or above the sinker tooth elevation (201) so as to allow the insertion of the yarn tail by said pusher element (7) within the tubular manufacture, and a second path portion to bring said needles (11) to the tuck stitch position.

2. The circular machine (1) according to claim 1, characterized in that said cam assembly (20) comprises, at the skirt (51a) of at least said lower cylinder (51), at least one skirt cam band (21), said at least one skirt cam band forming, between said first angular position (a) and said second angular position (0), at least one channel (33) for connection between said first path portion (31), arranged below said at least one skirt cam band (21), and said second path portion (32), arranged above said at least one skirt cam band (21), a control cam (40) being provided in order to move at least one element of said catenary-type movement assembly (10) from said first path portion (31) to said second path portion (32) through said at least one connecting channel (33).

3. The circular machine (1) according to claim 1, characterized in that said catenary -type movement assembly (10) comprises, at each groove formed at at least the lower cylinder (51), respective sliders (13) which are movable on command along respective axial grooves in order to move said needles (11) between a floating position, a drop stitch position and a tuck stitch position, said sliders (13) having at least one heel which is configured to be engaged, on command, along said lowered path (30).

4. The circular machine (1) according to claim 3, characterized in that said slider (13) is functionally associated with a respective sub-needle or oscillating jack (12) which can be engaged by said at least one control cam (40).

5. The circular machine (1) according to one or more of the preceding claims, characterized in that said catenary-type movement assembly (10) comprises sub-needles or oscillating jacks (12) associated with respective sliders (13) for the actuation of respective needles (11), said control cam(40).

6. The circular machine (1) according to claim 2, characterized in that it comprises a command and control device for the movement of said catenary-type movement assembly (10).

7. The circular machine (1) according to claim 6, characterized in that said command and control device comprises a links pattern actuator, said links pattern actuator being configured to control said at least one control cam (40).

8. The circular machine (1) according to claim 1, characterized in that said pusher element (7) comprises a device for emitting an air jet (7a) or a bristle brush device.

9. The circular machine (1) according to claim 1, characterized in that said pusher element (7) is arranged along the circumference of said lower and upper needle cylinders (51, 52) between said first angular position and said second angular position.

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