GB2175021A - Linking machine - Google Patents

Abstract

There is described a linking machine for joining various parts of knitted articles. The linking machine comprises a point ring onto which the parts to be joined are mounted and is provided with a single sewing station. The single sewing station is of the double stitch type and has a first needle bar and first co- operating yarn guide arranged on either side of the point ring and a second needle bar and second co- operating yarn guide arranged at said single sewing station, the second needle being parallel to and above the first needle bar and the second yarn guide being rigidly mounted adjacent the first yarn guide. The needle bars and yarn guides are provided with suitable drive means such as to effect the necessary sewing of the parts of the knitted garments with two chains of stitches. <IMAGE>

Description

SPECIFICATION Linking machine The present invention relates to a linking machine for joining knitted articles.

Conventional linking machines comprise a point ring for carrying the knitted garment to be worked and a needle, mounted on a needle bar and arranged internally or externally of the point ring. The needle co-operates with a yarn guide arranged on the opposite side of the point ring to that of the needle and therefore, respectively, externally or internally of said ring.

Each needle-yarn guide pair and its associated control means, constitute a sewing station capable of forming a corresponding chain of stitches.

For some applications such as, for example, the joining of sleeves, sides and other parts of knitted articles, it is convenient and often necessary to carry out a more robust sewing which is obtained by providing two sewing needles on traditional linking machines acting integrally and spaced in relation to the point ring by an amount which is constant, each needle being individually adapted to form a respective chain of stitches. The reciprocal arrangement of the sewing needles as well as being spaced, is such that the chains of stitches are formed at different heights, that is, one arranged above the other such that one needle works on a plane which is arranged above the plane of the points of the ring.

These known double stitch linking machines have a number of disadvantages and more importantly the requirement to use needles of the latch type in order to prevent the upper needle becoming entangled in the stitches of the fabric as a result of missing or reduced support effected by the points and of the resultant forward movement of the fabric.

It is an object of the present invention to obviate or mitigate these disadvantages and to this end employs, as illustrated in earlier Italian Patent Specification No 757,021 of the same applicant, a needle supported eccentricically on a needle bar which is provided with reciprocating axial and reciprocating angular motion.

According to the present invention there is provided a linking machine for joining knitted articles comprising:.

a point ring for supporting the knitted articles to be joined; a first needle bar and a first co-operating yarn guide arranged at a single sewing station adjacent the point ring; means to impart to said first needle bar reciprocating axial motion combined with reci procating angular motion; a second needle bar and second co-operating yarn guide arranged at said single sewing station, said second needle bar being arranged parallel to and above said first needle bar and said second yarn guide being rigidly mounted adjacent said first yarn guide; means for imparting to said second needle bar reciprocating axial motion combined with reciprocating angular motion; and each needle bar eccentrically carrying an needle, the eccentricity of the end of the needles in relation to the axis of its associated needle bar being such that, on each oscillation of the bar, the first needle moves in the same direction as the direction of motion of said point rings, and the second needle moves in a direction opposite to the direction of motion of the point ring.

The machine of the invention permits, on the one hand, the transformation of traditional linking machines into double stitch linking machines maintaining substantially unchanged the base structure and the needle bar movement mechanisms, and on the other hand, permitting the use of simple hook needles, not requiring latches. In fact, movement of the upper needle in the direction opposite to the motion of the points produced by the angular oscillation of the bar and the eccentricity of the needle, prevents the hook from becoming entangled in the stitches of the fabric during the phases in which the needle is extracted from the fabric itself.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an overall perspective view of a linking machine made in accordance with the present invention; Fig. 2 is a partial sectional perspective view showing a detail of the yarn guide means and their arrangement in relation to the point ring; Fig. 3 is a perspective view showing details of the double needle, single sewing station with the means for movement of the needle bar; Fig. 4 is an underneath view, to a greater scale, taken in the direction of the arrows IV IV of Fig. 3; Fig. 5 is a perspective view, showing the arrangement the eccentricity of the two needles in relation to each other and the direction of movements of each of the needles in relation to movement of the point ring;; Fig. 6 is a sectional view taken along the line VI-VI of Fig. 4; Fig. 6a is a sectional view similar to Fig. 6 showing the method of adjustment of the height of the second needle in relation to the points; Fig. 7 is a sectional view taken along the line VII-VII of Fig. 6; and Fig. 8 is a perspective view schematically showing the double row of chain stitches formed by the machine of the present invention.

Referring to the drawings, a double sewing linking machine 10 comprises a support tripod 11, a base 12 carrying a movable point ring 13, and an arm 14 which extends beyond the ring 13.

On the base 12 there is provided a drive train including a pair of helical cylindrical gears 15 and a pair of cylindrical gears 16, adapted to transfer motion from a motor 17, arranged in the centre of the tripoid 11, to a movable support 18 for first and second yarn guides 19,20.

The support 18 includes an eccentrically mounted bush 21 freely rotatable on an output shaft 22 of the pair of cylindrical gears 16 and a block 23, engaged through simple contact by a rod 26 which prevents rotation of the bush 21 whilst permitting, however, its eccentric orbital motion produced by rotation of the shaft 22. To the side of the bush 21 there is provided a seat 25 in which there is located the rod 26 at the extremity of which there is keyed a support arm 27. The free end of the arm 27 carries a transverse bar 28 at each of the ends of which there is integrally fixed a respective yarn guide 19,20.

As clearly shown in Fig. 2, the yarn guides are arranged internally of the- point ring 13 and their ends-provided with eyes 29,30 (Fig. 8) for the through passage of yarn -move along circular trajectories resulting from orbital motion of the bush 21. The point ring 13 rotates, in a known manner, about its own axis due to the action of a pinion (not shown) engaging a rack 31 integral with the ring itself; the pinion being driven by a worm screw/helical gear pair (not shown) integral with an output shaft 24 of the reduction gear pair 16.

At the end of the arm 14 there is removably fitted, by means of bolts 32, a head 33 with a shaft 34 which, through a conical.pair of gears 35, and other known drive means schematically illustrated and indicated by the numeral 36, receives motion from the motor 17. To the rigid structure of the head 33 there is articulately joined, through a hollow bush 37, an oscillating shackle type support 38.

Within the bush 37 there is freely movable a first needle bar 39 arranged opposite the first yarn guide 19. The free end of the shackle support 38 is in turn provided with a cylindrical through seat in which there is freely movable, parallel to the first needle bar 39, a second needle bar 40 arranged opposite-the second yarn guide 20. The two needle bars 39,40 are controlled in order to effect reciprocal axial movements combined with angular oscillations which are also reciprocal, and, to this end, a crank 41 is keyed to the lower end of the shaft 34 and, through a connecting rod 42 passes the reciprocal axial motion to a transverse yoke 43 connected to each of the needle bars 39,40 through movable clamping collars 55,56.The yoke 43 is provided with a pivot pin 44 for the connecting rod 42 which carries a triangular extension 42A with two end bushes 45,46 having bi-furcated lower portions in which there are engaged respective rigid pins 47,48. Each pin 47,48 is connected to the end of a corresponding crank arm 49,50 which in turn are keyed to the end of a respective needle bar 39,40.

Thus, rotation of the crank 41 provides, over and above reciprocal axial movement of the yoke 43, oscillation of the connecting rod 42 converted into angular oscillation of the needle bars themselves by the arms of cranks 49,50 and pins 47,48 which co-operate with them.

Also, by varying the inclination "I" of the shackle support 38 (Fig. 6a) there is varied the height of the second needle bar 40 in relation to the plane of the points 13. To this end, the support 38 is made to rotate relative to the bush 37 and fixed in the desired position through locking scews 51.

Each needle bar 39,40 carries a respective needle 59,60 of the known simple hook type, adapted to co-operate with its associated opposite yarn guide to form, in a known manner, a corresponding chain of stitches C1,C2.

As illustrated in Fig. 8, the chains are formed one above the other and the distance between them can be varied by varying the inclination of the shackle support 38 and consequently the height of the second needle 60 in relation to the first needle and to the plane of the point ring 13.

Further, the distance in the transverse direction between the two needles is chosen such that the chains of stitches are offset preferably by a half stitch.

As clearly illustrated in Fig. 5, each needle is supported by its associated needle bar such that its end is eccentric with respect to the axis of the bar but the eccentricity has a different orientation for the two needles.

The needle 59 has in fact its end at point A of the section of the bar 39 which, as a result of the angular motion of the bar 39, is moved in the same direction as movement of the ring 13, indicated by the arrow F. On the other hand the needle 60 has its end at point B of the bar 40 diametrically opposed to the point A. Therefore, as a result of the angular motion of the bar 40, the needle 60 moves in a direction opposite to that of the points 13.

This arrangement of opposed eccentricity prevents the hook of the needle 60 from becoming entangled with the stitches of the fabric during extraction of the needle itself. The needle 60 in fact acts above the point ring and, that is, in a portion of the fabric which is not maintained stretched by the points themselves such that, in the absence of said eccentric rotation, the hook has a marked tendency to become entangled in the fabric. Naturally, it is necessary that the hook of the needle is turned in the direction opposed to the movement of the needle itself, and therefore in the direction opposed to movement of the points.

From the preceding description it is evident that the machine according to the invention is easily derived from a similar conventional linking machine which can be transformed into the machine of the invention by replacing the known head, of the single needle bar type, by the head 33 having double needle bar as described, and providing on the arm 27 the transverse bar 28 for supporting the pair of yarn guides 19,20.

This transformation leaves unchanged the general structure of the machine and therefore also the kinematic chain for transmission of motion to the various mechanisms of the single sewing station.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims (10)

1. A linking machine for joining knitted articles comprising: a point ring for supporting the knitted articles to be joined; a first needle bar and a first co-operating yarn guide arranged at a single sewing station adjacent the point ring; means to impart to said first needle bar reciprocating axial motion combined with reciprocating angular motion; a second needle bar and second co-operating yarn guide arranged at said single sewing station, said second needle bar being arranged parallel to and above said first needle bar and said second yarn guide being rigidly mounted adjacent said first yarn guide; means for imparting to said second needle bar reciprocating axial motion combined with reciprocating angular motion; and each needle bar eccentrically carrying an needle, the eccentricity of the end of the needles in relation to the axis of its associated needle bar being such that, on each oscillation of the bar, the first needle moves in the same direction as the direction of motion of said point rings, and the second needle moves in a direction opposite to the direction of motion of the point ring.

2. A machine as claimed in Claim 1, wherein said single sewing station comprises a head removably connected to the structure of the machine and wherein said first and second needle bars are carried by an oscillating support mounted on said head; said support being articulated to the head through a hollow bush in which there is contained, in a freely movable manner, said first needle bar and being provided with a through hole in which there is freely movable said second needle bar.

3. A machine as claimed in Claim 2, wherein said oscillating support permits adjustment in height of the second needle bar with respect to the first needle bar and to the plane of the point ring.

4. A machine as claimed in either Claim 2 or 3, wherein said head includes a motor shaft with an end crank acting on a connecting rod which, through a connecting yoke produces the integral axial movement of both the needle bars, and through a triangular extension and co-operating crank arms, produces angular oscillation of said needle bars.

5. A machine as claimed in any preceding claim, wherein said yarn guides are mounted on a transverse bar mounted on an arm carried by an eccentric bush freely rotatable on a shaft controlled to carry out orbital motion.

6. A machine as claimed in any preceding claim, wherein the end of the needle carried by the first needle bar is arranged at a point on the section of the first needle bar such that, as a result of the angular motion of the bar, moves in the same direction as the point ring and wherein the end of the needle carried by second needle bar is arranged at a point on the section of the second needle bar such that, as a result of the angular motion of the bar, is moved in a direction opposite to that of the point ring.

7. A machine as claimed in any preceding claim, wherein said needle bars are mounted externally of the point ring and said yarn guides are mounted internally of the point ring.

8. A machine as claimed in any one of Claims 1 to 6 , wherein said needle bars are mounted internally of the point ring and said yarn guides are mounted externally of the point ring.

9. A machine as claimed in any preceding claim, wherein each needle bar carries a respective simple hook needle.

10. A linking machine for joining knitted articles substantially as hereinbefore described with reference to the accompanying drawings.